GuidebookfortheevaluationofstreammorphologicalconditionsbytheMorphologicalQualityIndex(MQI)

M.Rinaldi1,M.Bussettini1,2,N.Surian3,F.Comiti4,A.M.Gurnell5

1UniversityofFlorence;2ItalianNationalInstituteforEnvironmentalProtectionandResearch(ISPRA);3UniversityofPadua;4FreeUniversityofBozen;5QueenMaryUniversityofLondon.

October2016

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PremiseThis guidebook provides a detailed description of theMorphological Quality Index (MQI)and some integrated tools (MQIm, HMQI). The Morphological Quality Index (MQI) wasoriginallydevelopedinItaly(Rinaldietal.,2013),andthenexpandedandappliedtootherEuropeancountrieswithinthecontextoftheREFORMproject(Rinaldietal.,2015).The guidebook is an extension of the REFORM report (Rinaldi et al., 2015) with moreemphasis on low-energy streams and the inclusion of an Extended River Typology (ERT,Rinaldietal.,2016),whichishelpfulatvariousphasesofcharacterizationandassessment.Furthermore, an original tool, the Hydro-Morphological Quality Index (HMQI), has beendevelopedand isdescribed indetail.This tool includesanadditional indicator,concerningthealterationof flowswithoutpotentially relevanteffectsonchannelmorphology,whichprovides the opportunity to make an assessment of the overall hydromorphologicalconditionofariverreach.TheEvaluationFormsforconfinedandforpartlyconfined/unconfinedstreamsrespectively,adetailedGuidetotheCompilationoftheEvaluationForms,whichisusedtosupporttheapplicationof thetwo indices,andan IllustratedGuideareprovided in theAppendixesofthisguidebook.AcknowledgementsThe research has received funding from ISPRA (Istituto Superiore per la Protezione e laRicerca Ambientale, Roma) (project “Development of a system for the analysis, post-monitoring evaluation and definition of measures of impact mitigation aimed to anintegratedmanagement according to European Directives 2000/60/CE and 2007/60/CE”),and from the European Union’s FP7 programme under Grant Agreement No. 282656(REFORM).Laura Nardi, Barbara Belletti, Barbara Lastoria, and Bruno Golfieri have contributed invariousstagesoftheresearchandareacknowledged.

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Summary1 TheMorphologicalQualityIndex(MQI)..........................................................................71.1 Introduction....................................................................................................................................71.2 Maincharacteristicsofthemethod.........................................................................................71.3 Generalsettingandsegmentation...........................................................................................81.3.1 Step1:Physiographicsetting..............................................................................................................91.3.2 Step2:Confinement..............................................................................................................................111.3.3 Step3:Channelmorphology.............................................................................................................141.3.4 Step4:Otherelementsforreachdelineation............................................................................18

1.4 Furthercharacterization..........................................................................................................191.4.1 TheExtendedRiverTypology(ERT).............................................................................................211.4.2 Low-energyalluvialreaches.............................................................................................................27

1.5 Structureandkeycomponentsoftheevaluationprocedure.......................................281.6 Indicators.......................................................................................................................................301.7 Classesandscoresoftheindicators......................................................................................331.8 CalculationoftheMorphologicalQualityIndex(MQI)...................................................361.9 ApplicationoftheMQI...............................................................................................................381.9.1 Expertise....................................................................................................................................................381.9.2 Workingphasesandtimerequired................................................................................................381.9.3 Rangesofapplication...........................................................................................................................40

2 Integratedtools:HMQIandMQIm...................................................................................412.1 TheHydro-MorphologicalQualityIndex(HMQI).............................................................412.2 TheMorphologicalQualityIndexformonitoring(MQIm)............................................412.2.1 Introduction.............................................................................................................................................412.2.2 CharacteristicsoftheMQImanddifferenceswiththeMQI.................................................422.2.3 Scoringsystemandmathematicalfunctions.............................................................................422.2.4 Evaluationprocedures,limitationsandapplications.............................................................44

3 References...............................................................................................................................46

Appendix1.EvaluationFormforConfinedChannels......................................................50Appendix2.EvaluationFormforPartlyConfinedorUnconfinedChannels............56

Appendix3.GuidetotheCompilationoftheEvaluationForms..................................62A3.1 Introduction.....................................................................................................................63

A3.2 Generalityanddelineationofspatialunits............................................................63

A3.3 GeomorphologicalFunctionality...............................................................................64A3.3.1 F1:Longitudinalcontinuityinsedimentandwoodflux..........................................64A3.3.2 F2:Presenceofamodernfloodplain..............................................................................67A3.3.3 F3:Hillslope–rivercorridorconnectivity...................................................................73A3.3.4 F4:Processesofbankretreat............................................................................................74A3.3.5 F5:Presenceofapotentiallyerodiblecorridor..........................................................78A3.3.6 F6:Bedconfiguration–valleyslope...............................................................................80A3.3.7 F7:Planformpattern............................................................................................................83A3.3.8 F8:Presenceoftypicalfluvialformsinthefloodplain.............................................90A3.3.9 F9:Cross-sectionvariability..............................................................................................92A3.3.10 F10:Structureofthechannelbed.................................................................................98A3.3.11 F11:Presenceofin-channellargewood..................................................................102A3.3.12 F12:Widthoffunctionalvegetation..........................................................................105A3.3.13 F13:Linearextensionoffunctionalvegetation.....................................................109

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A3.4 Artificiality.....................................................................................................................111A3.4.1 A1:Upstreamalterationofflows..................................................................................112A3.4.2 A2:Upstreamalterationofsedimentdischarges....................................................119A3.4.3 A3:Alterationofflowsinthereach..............................................................................126A3.4.4 A4:Alterationofsedimentdischargeinthereach.................................................128A3.4.5 A5:Crossingstructures....................................................................................................132A3.4.6 A6:Bankprotections.........................................................................................................134A3.4.7 A7:Artificiallevées............................................................................................................136A3.4.8 A8:Artificialchangesoftherivercourse...................................................................139A3.4.9 A9:Otherbedstabilizationstructures........................................................................142A3.4.10 A10:Sedimentremoval.................................................................................................146A3.4.11 A11:Woodremoval........................................................................................................148A3.4.12 A12:Vegetationmanagement.....................................................................................150

A3.5 ChannelAdjustments.................................................................................................154A3.5.1 CA1:Adjustmentsinchannelpattern..........................................................................154A3.5.2 CA2:Adjustmentsinchannelwidth.............................................................................159A3.5.3 CA3:Bed-leveladjustments............................................................................................162

A3.6 Scores...............................................................................................................................166

A3.7 Sub-indices.....................................................................................................................167A3.8 References......................................................................................................................176

ListofFiguresFigure1.1DelineationofthecatchmentoftheVolturnoRiver(Italy)intolandscapeunits.__________________ 10Figure1.2PanoramicviewsofthelandscapeunitsintheVolturnoRivercatchment.________________________ 10Figure1.3Confinementclasses. __________________________________________________________________________________ 12Figure1.4Examplesofdifferentconfinementclasses. __________________________________________________________ 13Figure1.5ThesevenrivertypesoftheBasicRiverTypology(BRT)usedforthedelineationphase._________ 15Figure1.6Morphologiesofconfinedchannels.__________________________________________________________________ 16Figure1.7Examplesofmorphologiesofpartlyconfinedandunconfinedchannels.___________________________ 17Figure1.8Examplesofdiscontinuitiesconsideredduringthefinalstepofsegmentation.___________________ 19Figure1.9Initialdistinctionofbedconfigurationatreachscale.______________________________________________ 20Figure1.10Classificationofbedconfigurationatreach-scaleinsingle-thread,alluvialchannels.__________ 20Figure1.11Reach-scalemorphologiesinsingle-thread,alluvialchannels.___________________________________ 21Figure1.12Rivertypesfrom0to7oftheExtendedRiverTypology.__________________________________________ 24Figure1.13Rivertypesfrom8to22oftheExtendedRiverTypology._________________________________________ 24Figure2.1ProcedureforthedefinitionofthemathematicalfunctionofaMQImindicatorderivingfromthediscreteclassesofthesameMQIindicator.______________________________________________________________________ 44FigureA3.1Longitudinalcontinuityinsedimentandwoodflux.______________________________________________ 64FigureA3.2Longitudinalcontinuityinsedimentandwoodflux.______________________________________________ 65FigureA3.3Longitudinalcontinuityinsedimentandwoodflux.______________________________________________ 66FigureA3.4SketchoftheinteractionsbetweenF2andotherrelatedindicators._____________________________ 69FigureA3.5Differencesbetweenamodernfloodplainandarecentterrace. _________________________________ 71FigureA3.6Case1._______________________________________________________________________________________________ 71FigureA3.7Case2._______________________________________________________________________________________________ 72FigureA3.8Case3._______________________________________________________________________________________________ 72FigureA3.9Case4._______________________________________________________________________________________________ 72FigureA3.10Case5. _____________________________________________________________________________________________ 73FigureA3.11Case6. _____________________________________________________________________________________________ 73FigureA3.12Connectivitybetweenhillslopesandfluvialcorridor.____________________________________________ 74FigureA3.13Processesofbankretreat._________________________________________________________________________ 77

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FigureA3.14Potentiallyerodiblecorridor._____________________________________________________________________ 79FigureA3.15Bedconfigurationandvalleyslope._______________________________________________________________ 82FigureA3.16Bedconfigurationandvalleyslope.______________________________________________________________ 82FigureA3.17Examplesofalteredreaches._____________________________________________________________________ 87FigureA3.18.Planformpattern:examplesformulti-thread,transitional,andsingle-threadchannels._____ 89FigureA3.19Presenceoftypicalfluvialformsinthealluvialplain.___________________________________________ 91FigureA3.20Presenceoftypicalfluvialformsinthefloodplain.______________________________________________ 92FigureA3.21Variabilityofthecross-section.___________________________________________________________________ 94FigureA3.22Variabilityofthecross-sectioninconfinedchannels.___________________________________________ 95FigureA3.23Alterationofcross-sectionvariabilityinpartly-andunconfinedchannels.____________________ 96FigureA3.24Variabilityofthecross-sectioninpartly-andunconfinedchannels.___________________________ 97FigureA3.25Sometypesofalterationsofthesubstrate. _____________________________________________________100FigureA3.26Alterationofsubstrateinconfinedchannels.___________________________________________________101FigureA3.27Alterationsofsubstrateinpartly-andunconfinedchannels. __________________________________101FigureA3.28Presenceoflargewood.__________________________________________________________________________103FigureA3.29Vegetationinthefluvialcorridor________________________________________________________________105FigureA3.30Widthoffunctionalvegetationinconfinedchannels.__________________________________________107FigureA3.31Widthoffluvialcorridorinpartly-andunconfinedchannels._________________________________108FigureA3.32Widthoffunctionalvegetationinpartlyconfinedandunconfinedchannels._________________108FigureA3.33Linearextensionofthefunctionalriparianvegetationalongthebanks._____________________110FigureA3.34Ruleforassigningatransversalstructurethatcoincideswiththelimitbetweentworeachesanditseffectsonthealterationofsedimentandwaterdischarges.___________________________________________111FigureA3.35FlowchartoftheindicatorA1.__________________________________________________________________114FigureA3.36Alterationofflows.Typicalalterationstructures.______________________________________________116FigureA3.37Rangeofchannel-formingdischarges.__________________________________________________________116FigureA3.38Upstreamalterationofflows.____________________________________________________________________117FigureA3.39Transversalstructuresofalterationofsedimentdischargesinmountainareas._____________123FigureA3.40Transversalstructuresofalterationofsedimentdischargesinhillyandlowlandareas.____124FigureA3.41Upstreamalterationofsedimentdischarges(1)._______________________________________________125FigureA3.39Upstreamalterationofsedimentdischarges(2)._______________________________________________126FigureA3.42Otherstructuresthatcancauseanalterationofflowswithinareach._______________________127FigureA3.43Alterationofflowsinthereach._________________________________________________________________128FigureA3.44Ruleofevaluationoftheeffectsofadam/reservoiratthedownstreamlimitofthereach. _129FigureA3.45Alterationofsedimenttransport. _______________________________________________________________131FigureA3.46Caseswithveryhighdensityoftransversalstructures:________________________________________131FigureA3.47Crossingstructures.______________________________________________________________________________133FigureA3.48Crossingstructures.______________________________________________________________________________133FigureA3.49Bankprotectionstypes.__________________________________________________________________________135FigureA3.50Bankprotections:classification._________________________________________________________________135FigureA3.51Caseofgroynes. __________________________________________________________________________________136FigureA3.52Artificiallevées. __________________________________________________________________________________138FigureA3.53Artificiallevees. __________________________________________________________________________________138FigureA3.54Casesofbank-edgelevéesoccurringformostofthereach.____________________________________139FigureA3.55Artificialchangesofrivercourse._______________________________________________________________141FigureA3.56DrainageanddredgingworksinLow-Energy,fine-grainedstreams._________________________141FigureA3.57Artificialchangesofrivercourse._______________________________________________________________142FigureA3.58Otherbedstabilizationstructuresandrevetments.____________________________________________144FigureA3.59Otherbedstabilizationstructuresand/orrevetments.________________________________________145FigureA3.60Sedimentremoval. _______________________________________________________________________________147FigureA3.61Woodremoval.___________________________________________________________________________________149FigureA3.62Vegetationmanagement.________________________________________________________________________153FigureA3.63Adjustmentsinchannelpattern. ________________________________________________________________158FigureA3.64Adjustmentsinchannelwidth. __________________________________________________________________161FigureA3.65Bed-levelchanges.________________________________________________________________________________164FigureA3.66Fieldevidenceofincision.________________________________________________________________________164FigureA3.67Estimationoftheamountofincisionbasedondifferencesinelevationamongsurfaces.____165

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ListofTablesTable1.1Summaryofthegeneralsettingandsegmentationprocedure...........................................................................9Table1.2Definitionoffinalconfinementclassesbycombiningconfinementdegreeandconfinementindex.12Table1.3Criteriaandthresholdvaluesofindicesorotherdistinctivecharacteristicsforthemorphologicalclassificationofpartlyconfinedandunconfinedchannels.n.a.:notapplied...................................................................15Table1.4Characteristicgeomorphicunitsdefiningthebedconfigurationofalluvialchannelsatreachscale.............................................................................................................................................................................................................................20Table1.5Maincharacteristicsofthe7BasicRiverTypesand22morphologicaltypesoftheExtendedRiverTypology.........................................................................................................................................................................................................23Table1.6Descriptionofthe22morphologicaltypesoftheExtendedRiverTypes(ERT).........................................25Table1.7Listofindicatorsasafunctionofthemainaspects(continuity,morphology,vegetation)andcomponentsofassessment(functionality,artificiality,channeladjustments)...............................................................30Table1.8Definition,assessedparameters,assessmentmethods,andrangesofapplicationofeachindicator.............................................................................................................................................................................................................................31Table1.9Indicatorsofgeomorphologicalfunctionality:descriptionofclassesanddefinitionofscores...........34Table1.10Indicatorsofartificiality:descriptionofclassesanddefinitionofscores...................................................35Table2.1MaindifferencesbetweenMQIandMQIm.................................................................................................................42Table2.2Listofindicatorsforwhichthescoresaredefinedbymathematicalfunctions........................................43TableA3.1Relationsbetweenrangeofbedslopeandexpectedbedforms....................................................................81TableA3.2Channelmorphologiesgenerallyexpectedforsomemainphysicalsettings..........................................86TableA3.3DefinitionoftheclassesfortheindicatorA1.....................................................................................................114TableA3.4FlowchartforindicatorA1H...................................................................................................................................119TableA3.5DefinitionofclassesforindicatorA2.....................................................................................................................121TableA3.6FlowchartoftheindicatorA2..................................................................................................................................122TableA3.7Definitionofclassesasafunctionofthelengthofbank-edgeandcloselevées.................................137TableA3.8DefinitionoftheclassesfortheindicatorA12whenmanagementofemergentaquaticmacrophytesoccurs................................................................................................................................................................................151TableA3.9Classesforthedifferentpossibleadjustmentsinchannelmorphologies..............................................156

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1 TheMorphologicalQualityIndex(MQI)

1.1 Introduction

TheEUWaterFrameworkDirective (WFD) introduced the term ‘hydromorphology’,whichrequires the consideration of anymodifications to flow regime, sediment transport, rivermorphology, and lateral channel mobility. Several methods have been adopted forimplementing the WFD in European countries — in most cases coinciding with physicalhabitatassessmentprocedures(e.g.,RHS,Ravenetal.,1997;Lawa,2000).A critical analysis of hydromorphological assessmentmethods has been conducted in theREFORMDeliverable1.1(Rinaldietal.,2013),andsummarizedinBellettietal.(2015),withtheaimofidentifyingthemainstrengths,limitations,gaps,possibleintegrationofdifferentapproaches,andneedsforfurtherimprovements.Themaingapidentifiedinmostmethodsisaninsufficientconsiderationofphysicalprocesses.Toaddressthisgap,anincreasingefforthasbeenrecentlymadetodevelopmethodsbasedon a sounder geomorphological approach, with a stronger consideration of physicalprocessesatappropriatespatialandtemporalscales.TheRiverStylesFramework(BrierleyandFryirs,2005),theSYRAH(SystèmeRelationneld’Auditdel’HydromorphologiedesCoursd’Eau;Chandesrisetal.,2008),theIHG(IndiceHydrogeomorfologico;Ollero et al., 2007, 2011), the method proposed by Wyżga et al. (2010, 2012), and theMorphological Quality Index (MQI) (Rinaldi et al., 2013) are examples of morphologicalassessmentproceduresthatarebasedonageomorphologicalapproach.TheMorphologicalQualityIndex(MQI)wasinitiallydevelopedtobespecificallysuitableforthe Italian context, i.e. cover the full range of physical conditions, morphological types,degree of artificial alterations, and amount of channel adjustments. During the REFORMproject (Gurnell et al., 2014; Rinaldi et al., 2015), this method has been verified andexpanded to cover the full rangeofphysical conditions (physiographicunits,hydrological,andclimaticconditions,etc.)andthemorphologicaltypesofriversatEuropeanscale.

1.2 Maincharacteristicsofthemethod

ThemaincharacteristicsandinnovativefeaturesoftheMQIcanbesummarizedasfollows(Rinaldietal.,2013).(i) Themethod is based on anexpert judgement (i.e., a selection of variables, indicators,classes, and relative scores), deriving from the specific knowledge and experience of theauthors. This reflects the use of a ‘special’ rather than a ‘natural’ classification scheme(SneathandSnokal,1973;Kondolf,1995;Kondolfetal.,2003a).(ii) Themethod was designed to comply withWFD requirements, but could be used forotherpurposesinrivermanagement.(iii) Because themethod is to be usedby environmental orwater agencies on a nationallevel, it has been designed to be relatively simple and not excessively time consuming.However, its application should be carried out by trained people with an appropriatebackgroundandsufficientskillsinfluvialgeomorphology.(iv) Themethod is based on the consideration of processes (‘process-based’) rather thanonlyofchannelforms.Aspectssuchascontinuityinsedimentandwoodflux,bankerosion,lateralmobility,andchanneladjustmentsare taken intoaccount.On theotherhand, it isworthstressing that theaimof themethod is toassessmorphologicalquality,andnot to

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provideaquantificationofprocessesoranin-depthunderstandingofchannelevolutionandfuture dynamics. A rigorous evaluation of geomorphological processes would implymeasurementsatdifferenttimesofprocessrates(e.g.,bankerosionordeposition)ortheuseofquantitativemodellingoranalyses(e.g.,toassessalterationsinsedimenttransport).Suchaquantificationisnotfeasiblehavinginmindthepreviouspoint(iii).(v) The temporal component is explicitly accounted for by considering that an historicalanalysisofchanneladjustmentsprovidesinsightintothecausesandtimeofalterationsandinto future geomorphic changes. Lack of consideration of the temporal component isconsidered as oneof themain limitationsofmanyof theother geomorphic classificationschemes(Kondolfetal.,2003a). Inthismethod,weexplicitly includeindicatorsofchanneladjustmentsintheevaluationofrivermorphologicalquality.(vi) Concerning the spatial scales, the multiscale, hierarchical approach developed inREFORMbyGurnelletal.(2014,2016)isadopted,wherethe‘reach’(i.e.,asectionofriveralong which present boundary conditions are sufficiently uniform, commonly a fewkilometresinlength)isthebasicspatialunitfortheapplicationoftheevaluationprocedure.(vii)Morphological conditions are evaluated exclusively in terms of physical forms andprocesses without any reasoning on their consequences or implications in terms ofecologicalstate.Thismeansthatahighmorphologicalqualityisnotnecessarilyrelatedtoagood ecological state, although this is commonly the case. In fact, it iswidely recognisedthatthegeomorphicdynamicsofariverandthefunctioningofnaturalphysicalprocessesspontaneously promote the creation and maintenance of habitats and ensure theecosystem’sintegrity(e.g.,Kondolfetal.,2003b;BrierleyandFryirs,2005;Wohletal.,2005;Florsheimetal.,2008;Fryirsetal.,2008;HabersackandPiégay,2008).(viii) Reference conditions. According to the WFD, the reference state is given by‘undisturbed’ conditions showing no or only ‘very minor’ human impacts (EuropeanCommission,2003).Adetaileddiscussionon reference conditions forhydromorphology isreportedinRinaldietal.(2013).Insynthesis,referenceconditionsfortheMQIentailariverreachindynamicequilibrium,wheretheriverisperformingthosemorphologicalfunctionsthatareexpectedforaspecificmorphologicaltypology,andwhereartificialityisabsentordoesnotsignificantlyaffecttheriverdynamicsatthecatchmentandreachscale.(ix)TheMQIisnotsuitableforassessingsmallchangesinmorphologicalqualityand,moregenerally,formonitoringtheeffectsofaspecificmanagementorrestorationaction.Forthispurpose,theMorphologicalQuality Index formonitoring (MQIm:seechapter2) shouldbeused.(x)ThoughtheMQIdoesnotprovideanexplicit“targetvision”forpossibleriverrestoration,the evaluation structure provides a rational framework that is potentially useful forsupporting analyses of interventions and impacts and for identifying and prioritizingmanagementstrategies,adequaterestorationschemes,andmeasurementprogrammes.

1.3 Generalsettingandsegmentation

Thefirstphaseofthemethodisaimedatprovidingageneralsettingofphysicalconditionsandsubdividingtherivernetworkintorelativelyhomogeneousreaches,definedassectionsofriveralongwhichpresentboundaryconditionsaresufficientlyuniform(i.e.,withnosignificantchangesinvalleysetting,channelslope,imposedflowandsedimentload;BrierleyandFryirs,2005;Gurnelletal.,2014).

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Thisdelineationphasecoincideswith themulti-scalehierarchical frameworkdeveloped inREFORM(seeGurnelletal.,2014andRinaldietal.,2015formoredetails).Thefinalproductofthisphaseisthesubdivisionoftherivernetworkintoreaches.Thesearecommonlyafewkilometres in lengthand represent theelementary spatialunits for theassessmentof themorphologicalconditions.Table1.1Summaryofthegeneralsettingandsegmentationprocedure.(modifiedfromRinaldietal.,2013)

Steps Criteria OutputsStep1:generalsettingandidentificationoflandscape(orphysiographic)unitsandsegments

-geologicalandgeomorphologicalcharacteristics

-Landscapeunits-Segments

Step2:definitionofconfinementtypologies

-lateralconfinement -Confinementtypologies:confined(C)partlyconfined(PC)unconfined(U)

Step3:identificationofmorphologicaltypologies

-planimetriccharacteristics(sinuosity,braiding,andanabranchingindices)

-Morphologicaltypologies:Confined:singlethread,wandering,braided,anabranchingpartlyconfined-unconfined:straight,sinuous,meandering,wandering,braided,anabranching

Step4:otherelementsforreachdelineation

-furtherdiscontinuitiesinhydrology,bedslope,characteristicgeomorphicunits,bedsedimentcalibre,channelwidth,floodplainwidth

-Reaches

AccordingtotheoriginalversionoftheMQI(Rinaldietal.,2012,2013), fourstepscanbeusedduringthedelineationprocedure(Table1.1), includingsomeslightmodificationfromtheoriginalversiontoensurefullconsistencywiththeREFORMdelineationframework.ThefourstepsaresummarisedinTable1.1andinthefollowingsub-sections.

1.3.1 Step1:PhysiographicsettingAim: derive a general setting of the physiographic context and identify macro-areas(landscape or physiographic units) and macro-reaches (segments) with similarmorphologicalcharacteristics.Information/datanecessary:watershedarea,dominantlithologies,climateandhydrologicregime,landuse,riverlongitudinalprofiles.Methods: geological, geomorphological, and land usemaps; existing studies; hydrologicaldatacollectionandanalysis;Remotesensing/GIS;fieldreconnaissance.Results:divisionofthecatchmentintolandscapeunitsandoftheriversintosegments.Thelatteraremacro-reachesdefinedbytheintersectionofthechannelnetworkwithlandscapeunits, and by additional factors (e.g., major changes of valley setting, major tributaryconfluences).Description: based on existing material, the main landscape units in the catchment areidentified (Figures1.1and1.2).Theycanbe included in the followingmainphysiographicsettings: (1)mountains; (2)hills; (3)plains. Intermediatecases (e.g.,hillymountainareas)canbealsodefined.

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Theportionsofstreamsincludedwithinalandscapeunitaredefinedassegments.Withinasingle landscapeunit, the rivermaybe furtherdivided intomore segmentsdependingonadditional factors, including major changes of valley setting (confined, partly-confined,unconfined, as well as continuity of alluvial deposits) and gradient, major tributaryconfluences (a significant increase in upstream catchment area and river discharge).Segmentsnormallyhavealengthoftheorderofseveralkm(mountainareas)anduptotensofkm(lowlandareas).

Figure1.1DelineationofthecatchmentoftheVolturnoRiver(Italy)intolandscapeunits.(1)Mountainousunit;(2)Hillyunit;(3)Intermontaneplainunit;(4)Lowplainunit.

1

2

3

4

Figure1.2PanoramicviewsofthelandscapeunitsintheVolturnoRivercatchment.(1)Mountainousunit;(2)Hillyunit;(3)Intermontaneunit;(4)Lowplainunit.

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1.3.2 Step2:ConfinementAim: define river confinement in more detail, and sub-divide segments based onconfinement.Information/data necessary: width of the entire floodplain, confinement degree,confinementindex.Methods:Remotesensing/GIS;topographicandgeologicalmaps.Results:divisionofsegmentsbasedonconfinement.Description:toanalyzetheconfinementindetail,twoparametersareused:(1)confinementdegree;(2)confinementindex.

(1) Confinement degree. This evaluates the lateral confinement in the longitudinal valleydirection.Itcorrespondstothepercentageofriverbanksnotdirectlyincontactwiththeplain but with hillslopes or ancient terraces, over the total length of the two banks(BrierleyandFryirs,2005).Theplainishereidentifiedastheentirefloodplain,generallyconstituted by alluvial sediments (also indicated as alluvial plain), and is normallyidentified on geological maps with “present alluvium” or “Holocene alluvium”, whileancient terraces are older. Recent terraces generated by historical bed incision (e.g.,duringthelast100÷200years,asveryfrequentlyoccurinmanyEuropeancountries)arenotconsideredasancientterracesandforthepurposeoftheconfinementarepartoftheentirefloodplain.Inadditiontoachronologicalcriterion,furtherfactorsfordefiningtheconfinementcanbethedifferenceofelevationandtheerodibilityofthematerial.Forexample,aHolocene terraceof10÷15m isnotpartof the floodplain.However,aPleistoceneterraceseparatedbyadifferenceinlevelofafewmeterscanbeconsideredas part of the floodplain, exceptwhen thematerial is strongly cemented. Finally, thefloodplain is not always comprised of alluvial sediments. In Northern Europe, someplains have been generated by fluvio-glacial or fluvio-lacustrine processes, and arecharacterised by a large sediment size variability, ranging from very fine (lacustrinedeposits) to coarse (glacial or fluvio-glacial deposits). In these cases, the floodplain isintendedinabroadersenseasasurfacethatdoesnotconfineriverdynamics(intermsof floodingand/or lateralerosion),andthealtimetricanderodibilitycriteriashouldbeused (i.e., thedifference inelevationwith thechannelbedshouldbe limited toa fewmeters,andthematerialshouldnotbestronglyconsolidatedorcemented).Oncetheelementsofconfinement(hillslopesandancientterraces)havebeendelimited,threecasescanbedistinguishedbasedontheconfinementdegree (BrierleyandFryirs,2005;Rinaldietal.,2013;Gurnelletal.,2014):- Confined channels: more than 90% of the banks are directly in contact with

hillslopesorancient terraces.The floodplain is limited to some isolatedpockets (≤10%).

- Partlyconfinedchannels:banksareincontactwiththefloodplainforalengthfrom10to90%.

- Unconfinedchannels: lessthan10%ofthebanklengthis incontactwithhillslopesorancientterraces.Infact,thefloodplainisnearlycontinuous,andtheriverhasnolateralconstraintstoitsmobility.

In some cases, the confinement degree previously defined is not sufficient toappropriately define the confinement characteristics. In fact, it is not infrequent

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(particularly inmountainareas) tohavestreamswithaverynarrow(somemeters)butquitecontinuousfloodplainonthesidesoftherivermakingcontactwiththehillslopes.Accordingtothepreviousdefinitions,suchstreamsmayfallintothecategoriesofpartlyconfined or unconfined, while for the purposes of this method it would be moreappropriate to consider them as confined. Therefore, an additional parameter is usedherewhichtakesintoaccountthewidthofthefloodplain,andisdefinedasfollows.

(2) Confinement index. It is defined here as the ratio between the floodplain width(including the channel) and the channel width. Consequently, the index is inverselyproportionaltotheconfinement:aminimumvalueof1indicatesthatthefloodplainandchannel coincide (i.e. there is no floodplain), while the index increases when thefloodplainincreasesitswidthrelativelytothechannelwidth.Basedontheconfinementindex,thefollowingclassesareidentified:- highconfinement:indexrangingfrom1to1.5;- mediumconfinement:indexrangingfrom1.5ton;- lowconfinement:indexhigherthann;where n = 5 for single-thread channels, and n = 2 for multi-thread or transitional(wandering)morphologies.Thehighervalue forsingle-threadchannels reflects the factthat a sufficientlywide floodplain is needed for these channels to develop completelyfreemeanders,equaltoabout4.5timesthechannelwidth(LeopoldandWolman,1957).

Based on the confinement degree and confinement index, the three final classes ofconfinementaredefined,accordingtoTable1.2(Figures1.3and1.4).Table1.2Definitionoffinalconfinementclassesbycombiningconfinementdegreeandconfinementindex.(fromRinaldietal.,2012)

Confinementclass DescriptionConfined

Allcaseswithconfinementdegree>90%Confinementdegreefrom10%to90%andconfinementindex≤1.5

Partlyconfined Confinementdegreefrom10%to90%andconfinementindex>1.5Confinementdegree≤10%andconfinementindex≤n

Unconfined Confinementdegree≤10%andconfinementindex>n

Confined Partlyconfined Unconfined

CD>90% CD=10÷90% CD=10÷90% CD≤10% CD≤10% CD=0 CI≤1.5 CI>1.5 CI≤n CI>n CI>n

Figure1.3Confinementclasses.Ingreen:floodplain;inbrown:hillslopes(orancientterraces).Cd:confinementdegree;Ci:confinementindex=Wp/W,whereWp:floodplainwidth(includingthechannel)andW:channelwidth.

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1

2

3

4

5

6

Figure1.4Examplesofdifferentconfinementclasses.(1),(2)Confinedchannels;(3),(4)partlyconfinedchannels;(5),(6)unconfinedchannels.

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1.3.3 Step3:ChannelmorphologyAim:defineandclassifychannelmorphology.Information/data necessary: confinement, sinuosity index, braiding index, anastomosingindex(bedconfiguration).Methods:Remotesensing/GIS;fieldreconnaissance.Results:divisionofsegmentsbasedonchannelmorphology.Description: the first levelofmorphological classificationused for thedelineationof riverreaches is based on river channel planform character (number of threads and planformpattern) in the context of valley setting (confinement). This Basic River Typology (BRT)(Rinaldietal.,2011,2015,2016;Gurnelletal.,2014)definessevenrivertypesusingreadily-available information,mainlyby remotely-sensed imagery (Figure1.5).Different typesareassociatedwithtwobroadcategoriesofvalleyconfinement.

Confinedchannelsarefirstdividedintotwobroadcategories(single-thread,multi-threadorwandering).Forsingle-thread,sinuosity isnotmeaningfulas it isdeterminedbythevalleyrather than the channel planform. These channels are not further classified at this stage,becauseitisnotpossibletomakeaccuratedistinctionsbasedonothercharacteristics(e.g.,bed configuration) from remotely sensed sources. Transitional andmulti-thread confinedreaches are identified using the same criteria as for unconfined and partly-confinedchannels (seebelow). In conclusion,only fourBRTof confinedchannelsarediscriminated(Figure1.6):single-thread(straight-sinuous),wandering,braided,anabranching.

Partly confined and unconfined channels are classified based on their planimetriccharacteristics using the following indices: (1) sinuosity index; (2) braiding index; (3)anabranchingindex.- SINUOSITYINDEX(Si)isdefinedastheratiobetweenthedistancemeasuredalongthe

(main) channel and the distance measured following the direction of the overallplanimetriccourse(or‘meanderbeltaxis’forsinglethreadrivers).

- BRAIDINGINDEX(Bi)isdefinedasthenumberofactivechannelsatbaseflowseparatedbybars.

- ANABRANCHING INDEX (Ai) is defined as the number of active channels at baseflowseparatedbyvegetatedislands.

Based on these parameters, the following six Basic River Types of partly confined andunconfinedchannelsaredefined(Table1.3,Figure1.7):- Single-threadchannels:straight,sinuous,meandering- Transitionalchannels:wandering- Multi-threadchannels:braided,anabranching.

Furthermorphologies,describedby theExtendedRiverTypology (ERT: seeGurnelletal.,2014; Rinaldi et al., 2015, 2016), are identified during Step 4 and/or during thecharacterizationandassessmentstages.

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Table1.3Criteriaandthresholdvaluesofindicesorotherdistinctivecharacteristicsforthemorphologicalclassificationofpartlyconfinedandunconfinedchannels.n.a.:notapplied.(modifiedfromRinaldietal.,2012,2013,andfromGurnelletal.,2014)

Typology Sinuosityindex(Si)

Braidingindex(Bi) Anabranchingindex(Ai)

Straight(ST) 1≤Si<1.05 1÷1.5(normallyapprox.1)

1÷1.5(normallyapprox.1)

Sinuous(S) 1.05≤Si<1.5 1÷1.5(normallyapprox.1)

1÷1.5(normallyapprox.1)

Meandering(M) ≥1.5 1÷1.5(normallyapprox.1)

1÷1.5(normallyapprox.1)

Wandering(W) n.a. 1≤Bi<1.5 1≤Ai<1.5Braided(B) n.a. ≥1.5 <1.5Anabranching(A) n.a. 1÷1.5 ≥1.5

Figure1.5ThesevenrivertypesoftheBasicRiverTypology(BRT)usedforthedelineationphase.

Extended river typology (ERT)

Following the initial delineation of river reaches, the multi-

scale hierarchical framework includes a characterizationphase, during which additional information on reach

properties and indicators is collected. Based on this addi-

tional knowledge, an extended river typology (ERT) hasbeen developed.

Although the ERT is informed by previous geomor-

phological research (e.g. Schumm 1985; Rosgen 1994;Knighton and Nanson 1993; Nanson and Knighton 1996;

Montgomery and Buffington 1997; Church 2006; Fuller

et al. 2013; Nanson 2013), it is designed for practicalapplication by stakeholders and river managers, and it

builds explicitly on the simple BRT classification described

in the previous section.Twenty-two extended morphological types are dis-

criminated (Table 1; Figs. 2 and 3) according to their

confinement (confined, partly confined, unconfined), dom-inant bed material size (bedrock, boulder, cobble, gravel,

sand, silt), and planform (straight-sinuous, meandering,

pseudo-meandering, wandering, braided, island-braided,anabranching). The following points should be noted:

1. the extended types are intended as ‘naturally-function-ing’ morphologies to the degree that they have some

ability to adjust their plan- and bed-form. Therefore

type 0 (highly altered reaches) is retained in the

extended typology for any reach with a predominantly

artificial bed and/or heavily engineered, stabilisedbanks.

2. Straight and sinuous types are combined in the ERT(Table 1), because both types are related to similar

morphological units when they possess similar bed

material and level of confinement. However, to avoidinconsistency between the classifications, the combi-

nation of, for example, a ‘straight’ channel (simple

classification) with a ‘straight-sinuous with alternatebars’ (extended classification) should lead to a ‘straight

with alternate bars’ extended type.

3. A new transitional type, ‘pseudo-meandering’ isincorporated to describe straight or sinuous channels

that display large, alternate bars at low flow (Bartholdy

and Billi 2002; Rinaldi 2003; Visconti et al. 2010).While the bankfull channel conforms to a straight or

sinuous channel, the low flow channel is so heavily

affected by the exposure of alternate bars that it wouldbe defined as meandering if its Si index were to be

calculated.

The river types are arranged in Figs. 2 and 3 to provideindirect information on the typical spatial distribution of

channel morphologies in a fluvial system, as they are

linked to confinement, sediment particle size (decreasingfrom top to bottom of the figures), and to sediment quantity

and river energy (from left to right along each line in the

Fig. 1 The seven river types of the basic river typology

20 M. Rinaldi et al.

123

Author's personal copy

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1

2

3

4

Figure1.6Morphologiesofconfinedchannels.(1)Confinedsingle-thread;(2)confinedwandering;(3)confinedbraided;(4)confinedanabranching.

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1

2

3

4

5

6

Figure1.7Examplesofmorphologiesofpartlyconfinedandunconfinedchannels.(1) Straight; (2) sinuous; (3)meandering; (4)wandering; (5) braided; (6) anabranching (in the photo, the islands andfloodplainareinundated).

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1.3.4 Step4:OtherelementsforreachdelineationAim:finalizethedelineationofreachesaccountingforadditionalfactors.Information/data necessary: hydrologic discontinuities (tributaries, dams), longitudinalprofile,artificiality,widthoffloodplain,channelwidth.Methods: Remote sensing/GIS; longitudinal profile by topographic maps; fieldreconnaissance.Results: segments are divided into reaches, representing the basic spatial unit for theapplicationoftheMQI.Description: the following additional aspects are considered in this step as criteria for afurtherdivisionintoreaches(Figure1.8).

- Changeingeomorphicunits.WithinareachwithasameBasicRiverType(accordingto step3), adistinct change in the typical assemblageof geomorphicunits canbenoted and used as an additional criterion for sub-dividing the reach. Changes ingeomorphic units and/or in sediment size are reflected in a change of river type,according to the Extended River Typology (ERT: see next section). For example, asinuousreachmaybecharacterisedbyafirstportionwithcontinuous,alternatebars(type12oftheERT)andasecondpartwithonlyoccasionalbars(type13oftheERT):in this case, two distinct sinuous reaches can be distinguished characterised by adifferentpatternofbars.

- Discontinuities in bed slope. This is particularly important in the case of confinedchannelswhere importantandabruptchanges inbedslopecanbenotedfromthelongitudinalprofile.

- Tributaries. Tributaries determining significant changes in flow discharge orsedimenttransportcanbeconsideredinthisstep.

- Dams and other artificial elements. Artificial discontinuities are mainly identifiedwithdams,whicharealwaysassumedasa limitbetween reaches. Similarly,checkdamsordiversionstructuresof relevantsizesarenormallyconsideredasa limitofthe reach. Furthermore, heavily artificial streams (type 0 of the ERT) are alsoconsideredinthisstep,suchasastreamreachcrossinganurbanarea,oramountainstreamwithbedrevetmentsand/orasequenceofconsolidationcheckdams.

- Change in confinement and/or size of the floodplain: in some cases, this can beconsideredasanadditionalcriterion.

- Changes in sediment size: casesofa considerableandsuddenchange in sedimentsize, e.g. a passage from gravel-bed to sand-bed, can be considered a criterion ofseparation in different reaches. This can be reflected in a change of river type,according to the Extended River Typology. For example, a sinuous reach may becharacterisedbyafirstportionwithagravelbed(type13oftheERT),andasecondpartwithasand-bed(type17oftheERT):inthiscase,twodistinctsinuousreachescanbedistinguished.

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1

2 3

Figure1.8Examplesofdiscontinuitiesconsideredduringthefinalstepofsegmentation.(1) Hydrological discontinuity due to a major tributary (reaches 1 and 2); dam (D) (reaches 2 and 3: note that thereservoirisnotconsideredasariverreach).(2)Discontinuityinbedslope(confinedreaches).(3)Otherdiscontinuitiesthatcanbeusedforriversegmentation:changeinsizeofthefloodplain(from3to4);changeinchannelwidth(from4to5).

1.4 Furthercharacterization

Following the initial delineation of river reaches, the multi-scale hierarchical frameworkincludesacharacterizationphase,duringwhichadditionalinformationonreachpropertiesandindicatorsiscollected.Thisinformationiscollected,partly,duringthefieldsurvey,andtherefore is not required for the segmentation. In some cases the segmentation can beamended if field observations lead to the identificationof some additional elements thatwerenotobservedbyremotesensing(forexample,asignificantchangeinsedimentsize).Thefirstsetofinformationconcernsthefollowingfeatures:(i)drainagearea;(ii)dominantbed sediment; (iii)meanbed slope; (iv)meanchannelwidth; (v)bedconfiguration. ThisinformationsupportsthedefinitionoftheExtendedRiverTypeandenergysetting(seenextsections). Additional data/information concerning sediment size and discharge, whenavailable,canbealsoincluded.

Concerning bed configuration, the following bed morphologies are distinguished(MontgomeryandBuffington,1997;Gurnelletal.,2014)(Figures1.9,1.10,1.11;Table1.4):- Bedrockchannels;- Colluvialchannels;- Alluvialchannels:cascade,steppool,planebed,rifflepool,duneripple;- Artificialbed.

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1 2 3

Figure1.9Initialdistinctionofbedconfigurationatreachscale.(1)Bedrockchannel;(2)colluvialchannel;(3)alluvialchannel.

Figure1.10Classificationofbedconfigurationatreach-scaleinsingle-thread,alluvialchannels.(modifiedfromMontgomery&Buffington,1997)

Table1.4Characteristicgeomorphicunitsdefiningthebedconfigurationofalluvialchannelsatreachscale.

REACHSCALE GEOMORPHICUNITSCASCADE CASCADESSTEPPOOL STEPS,POOLSPLANEBED RAPIDS,GLIDESRIFFLEPOOL RIFFLES,POOLS,GLIDESDUNERIPPLES DUNE,RIPPLES

Bed profile Planform

Cascade

Step pool

Riffle pool

Dune ripple

Plane bed

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1

2

3

4

5

Figure1.11Reach-scalemorphologiesinsingle-thread,alluvialchannels.(1)Cascade;(2)steppool;(3)planebed;(4)rifflepool;(5)duneripple.

1.4.1 TheExtendedRiverTypology(ERT)Based on this additional knowledge, the Extended River Typology (ERT) (Gurnell et al.,2014;Rinaldietal.,2015,2016)isapplied.Thismoredetailedcharacterizationoftherivertype of the assessed reach is important, given that many MQI indicators are type-dependent, i.e. the range of application of each MQI indicator is mainly based on theExtendedRiver Type. TheERT classification is alsouseful tobetterplace the reach in thecontextofthecatchmentandofthecontrollingphysicalconditions(e.g.,valleyslope,flowenergy,sedimentsupply,etc.),specificallytosupporttheassessmentof impactedreacheswherechannelmorphologymaybeoutofcontext(seelater).Although theERT is informedbypreviousgeomorphological research, itwasdesigned forpracticalapplicationbystakeholdersandrivermanagers(Rinaldietal.,2016),anditbuildsexplicitlyonthesimpleBRTclassificationdescribedintheprevioussection.Twenty-two Extended River Types are discriminated (Table 1.5, Figures 1.12 and 1.13)according to their confinement (confined, partly confined, unconfined), dominant bedmaterial size (bedrock,boulder, cobble, gravel, sand, silt), andplanform (straight-sinuous,meandering, pseudo-meandering, wandering, braided, island-braided, anabranching). Thefollowingaspectsshouldbetakenintoaccount:(i) The Extended River Types are not intended to be ‘reference conditions’ (for thedefinition of reference conditions see section 1.5). It is important to note that reference

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conditionsarenotdefined in termsofaprecisechannelconfigurationorasetofchannelcharacteristicsbuttheyareratherdefinedintermsofdynamicprocessesandfunctionsthatareexpected tonormallyoccur inagivenphysical context.The typeof reasoningsuchas‘reachmorphology is type13but shouldbe type8’has tobeavoided,becausea reliablepredictionofwhichshouldbethe‘natural’morphologyintheabsenceofhumanpressuresisnotfeasibleandisoutofthescopesoftheMQI.(ii) The extended types are intended as ‘naturally-functioning’ morphologies to thedegree that they have some ability to adjust their plan- and bed-form. Therefore type 0(highly altered reaches) is retained in the extended typology for any reach with apredominantlyartificialbedand/orheavilyengineered,stabilisedbanks.(iii) StraightandsinuoustypesarecombinedintheERT(Table1.5),becausebothtypesare related to similarmorphological units. However, to avoid inconsistency between theclassifications, thecombinationof, forexample,a ‘straight’channel (BRT)witha ‘straight-sinuouswithalternatebars’ (ERT) should lead toa ‘straightwithalternatebars’extendedtype.(iv) Anewtransitionaltype,‘pseudo-meandering’,isincorporatedtodescribestraightorsinuouschannelsthatdisplay large,alternatebarsat lowflow.Whilethebankfullchannelconformstoastraightorsinuouschannel,thelowflowchannelissoheavilyaffectedbytheexposureofalternatebarsthatitwouldbedefinedasmeanderingifitsSiindexweretobecalculated.

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Table1.5Maincharacteristicsofthe7BasicRiverTypesand22morphologicaltypesoftheExtendedRiverTypology.(from Rinaldi et al., 2016). ERT: Extended River Type; BRT: corresponding Basic River Type; C: Confined; PC: Partlyconfined;U:Unconfined.Inbold:dominantbedmaterialtype/size.ERT(BRT) Predominant

confinementclass

Bedmaterialsize Planform Typicalslope(mm-1)

HeavilyArtificial0(0) C,PC,U Artificial Any AnyBedrockandColluvialChannels1(1) C Bedrock Straight-Sinuous Usuallysteep2(1) C Coarsemixed Straight-Sinuous Steep3(1) C Mixed Straight-Sinuous Lowerthan

ERTs1and2AlluvialChannels4(1) C Boulder Straight-Sinuous >>0.045(1) C Boulder,Cobble Straight-Sinuous >0.046(1) C Boulder,Cobble,

GravelStraight-Sinuous >0.02

7(1) C Cobble,Gravel Straight-Sinuous >0.018(6) C,PC,U Gravel,Sand Braided <0.049(6) C,PC,U Gravel,Sand Island-Braided <0.0410(7) C,PC,U Gravel,Sand Anabranching(high

energy)<0.01

11(5) C,PC,U Gravel,Sand Wandering <0.0412(3) C,PC,U Gravel,Sand Pseudo-

meandering<0.04

13(2/3) PC,U Gravel,Sand Straight-Sinuous <0.0214(4) PC,U Gravel,Sand Meandering <0.0215(6) C,PC,U FineGravel,Sand Braided <0.0216(3) C,PC,U FineGravel,Sand Pseudo-

meandering<0.02

17(1/2) PC,U FineGravel,Sand Straight-Sinuous <0.0218(4) PC,U Finegravel,Sand Meandering <0.0219(7) C,PC,U FineGravel,Sand Anabranching <0.00520(2/3) PC,U FineSand,Silt,Clay Straight-Sinuous <0.00521(4) C,PC,U FineSand,Silt,Clay Meandering <0.00522(7) C,PC,U FineSand,Silt,Clay Anabranching <0.005

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Figure1.12Rivertypesfrom0to7oftheExtendedRiverTypology.

Figure1.13Rivertypesfrom8to22oftheExtendedRiverTypology.

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TherivertypesarearrangedinFigures1.12and1.13toprovideindirectinformationonthetypicalspatialdistributionofchannelmorphologiesinafluvialsystem,astheyarelinkedtoconfinement,sedimentparticlesize(decreasingfromtoptobottomoftheFigures),andtobedloadtransportandriverenergy(fromlefttorightalongeachlineintheFigures).Figure1.12 illustrates typical confined channel morphologies located in the upper portion of acatchment, whereas in Figure 1.13 the typical downstream distribution of channelmorphologies tendstomovefromtop left tobottomright.However,deviations fromthisprinciplearepossibledependingon the specific conditionsof the catchment (e.g., due tothealternationoflowerenergy,alluvialreachesandhigherenergy,confinedreaches,ortootherfactors).The 22 extended types are not an exhaustive list of possible combinations of planform,valley setting, sediment size, and geomorphic units, but rather an indicative, generalframework for identifying catchment- or region-specific ranges of morphologies. This isbecause river characteristics cannotbeneatlydivided into classes, theyvary continuouslyand thus transitional types are likely to be encountered quite frequently (Kondolf et al.,2003). Furthermore, the set of distinguishingmorphological attributesmay vary betweenbiogeographical regions andmay be degraded or reduced by human interventions, but acheck-listoftheunitsthatmaybepresentwithinthechannelanditsfloodplainisprovidedinTable1.6asastartingpoint.

Table1.6Descriptionofthe22morphologicaltypesoftheExtendedRiverTypes(ERT).(fromRinaldietal.,2016).Geomorphicunits:AB:Alternatebar;AC:Abandonedchannel;B:Bar;Be:Bench;BL:Boulderlevées;Bs:Backswamp;C:Cascade;CC:Crevassechannel;Ch:Chutes;Co:Cut-offchannel;CS:Crevassesplay;F:Forced;G:Glide;I:Island;L:Levées;LB:Lateralbar;MB:Marginalbar;MCB:Mid-channelbar;P:Pool;PB:Pointbar;PBe:Pointbench;Po:Pond;R:Riffle;Ra:Rapids;RD:Ripples(andDunes);RS:Rockstep;RSw:RidgeandSwale;SB:Scrollbar;Sc:Scroll;SP:Step-Pool;SS:Sandsplay;VI:Vegetationinduced.ERT GeomorphicUnits Stability Description0 PossibleoccasionalB VeryStable Highlymodifiedreaches1 RS,C,Ra Usuallystrongly

confinedandhighlystable

Sedimentsupply-limitedchannelswithnocontinuousalluvialbed

2 BL,C,SS,AC Canbehighlyunstable

Small,steepchannelsattheextremitiesofthestreamnetwork

3 Poorlydefined,featurelesschannels.

Verystable,shallow(oftenephemeral)channels

Small,relativelylowgradientchannelsattheextremitiesofthestreamnetwork

4 C,P Stableforlongperiodsbutoccasionalcatastrophicdestabilisation

Verysteepwithcoarsebedmaterialconsistingmainlyofbouldersandlocalexposuresofbedrock

5 SP Stableforlongperiodsbutoccasionalcatastrophicdestabilisation

Sequenceofchannelspanningaccumulationsofbouldersandcobbles(steps)separatedbypools

6 G,Ra,FB,FP Relativelystableforlongperiods,butfloodscaninducelateralinstabilityandavulsions

Predominantlysinglethreadbutsecondarychannelsaresometimespresent

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7 R,P,G,LB Subjecttofrequentshiftingofbars

Coarsecobble-gravelsedimentssortedtoreflecttheflowpatternandbedmorphology

8 MCB,R,P Usuallyhighlyunstablebothlaterallyandvertically

Multiplechannelsseparatedbyactivebars(bar-braided)

9 I,MCB,R,P

Usuallyunstablebothlaterallyandvertically

Distinguishedfromtype11by>20%channelareacoveredbyislandsofestablishedvegetation

10 I,R,P Lateralinstabilityusuallypresent

Islandscoveredbymaturevegetationextendbetweenchannels

11 I,MCB,MB,R,P

Usuallyhighlyunstablebothlaterallyandvertically

Exhibitswitchingfromsingletomulti-thread

12 Large,continuousAB,R,P

Usuallyunstablebothlaterallyandvertically

Differsfromtype11initslowersinuosityandverypronouncedalternatinglateralbardevelopment

13 Largealternate(continuous)PB,R,P

Subjecttofrequentshiftingofbars

Sinuouspatternwithdiscontinuousbarsofcoarsesediment

14 R,P,PB,Ch,Co,SB,Pbe

Laterallyunstablechannelssubjecttolateralmigration

Meanderingpatternwithfrequentpointbarsofcoarsesediment

15 B,RD Unstablebothlaterallyandvertically

Samemorphologyastype8butwithpredominantlysandmaterial

16 Continuous,largeAB,P,RD

Verticallyunstableduetobarmovementandsometimeslaterallymigrating

Highlysinuousbaseflowandalternatingbarswithinastraighttosinuouschannel

17 R,P,PB,RD,occasionalBe,SB,L,Bs

Laterallyunstablechannelssubjecttolateralmigration

Samemorphologyastype13butwithpredominantlysandmaterial

18 P,PB,RD,S,L,RSw,Bs,AC

Unstablechannelssubjecttomeanderloopprogressionandextensionwithcut-offs

Samemorphologyas14butwithpredominantlysandmaterial

19 I,RD,L,VIB,VIBe,RD,AC

Stable Vegetationstabilisingbarsbetweenchannelthreads,formingislandsthatdevelopbyverticalaccretionoffinesediment

20 L,Bs Verystable Silttosilt-claybanksoftenwithhighorganiccontentarehighlycohesive

21 L,Bs,Pbe Verystable Similarto20butwithhighersinuosity22 I,L,CC,CS,Po,VIB,

VIBe,AC,Bs

Verystable Silttosilt-claybanksoftenwithhighorganiccontentarehighlycohesive;extensiveislandscoveredbywetlandvegetation

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1.4.2 Low-energyalluvialreachesBased on the additional knowledge (sediment size, bed slope, etc.) and the furthercharacterization obtained through the ERT, at this stage it is useful to discriminate Low-Energy streams (LE) fromothermedium-highenergy streams. Thisdistinction isuseful tobetterdefinetherangeofapplicationofsomeindicatorsduringtheapplicationoftheMQI.In fact, some indicatorsareexclusive to low-energy streams,whereasother indicatorsdonotapplytothesestreams.Thedefinitionoflow-energystreamsisbasedonthefollowingfeatures:(i) The most suitable parameter to discriminate between low energy and medium-highenergyistheunitstreampower,ω (Wm-2),definedasω =Ω/W,whereΩ=γ QSisthetotal(cross-sectional) stream power, γ is the unit weight of water (= 9800 Nm-3), Q is thedischarge(atformativeflows,i.e.Q1.5orQ2)(m3/s),Sisthebedslope(mm-1).Typicallow-energyconditionsaregenerally identifiedwithunit streampower<10Wm-2 (Nanson&Croke,1992).(ii) If the discharge at formative flows is not available, the unit stream power cannot beestimated.For thesecases,bedslope canbeusedasanalternativeparameter.Aprecisethreshold in termsof bed slope is notwell definedbecause the energy conditions of thestream(i.e.thestreampower)dependontheproductofslopeanddischarge,(e.g.,streamswithverylowslopebuthighdischargemaynotbeclassifiedaslow-energystreamsandviceversa). However, a bed slope ≤ 0.001 is normally associated to low energy conditions.Caution shouldbeused in reacheswith thepresenceof grade-control structures (suchascheckdams) thatmay substantially reduce thebed slope. In such cases, themeanvalleyslopeshouldbeused.(iii) The physiographic context of the reach should be also considered, in terms of thelandscape unit, and consequently the relief of the surrounding areas and the potentialsediment sources, controlling the sediment delivery for bedload. Low-energy streams aretypically associatedwith lowland or coastal plains, with low gradients and relatively lowbedload,mainlycomposedofsandandfinersediment.However,low-energyreachescanbeoccasionally found in mountain or hilly areas, for example along low-slope formerly-glaciatedvalleys.(iv) Bed sediment is predominantly fine (sand, silt, clay), although (fine) gravel canoccasionallyoccur.Bankmaterialisalsomostlycohesive.(v) Channel planform is typically single-thread (from straight to meandering) or multi-thread,anastomosing(i.e.,lowenergyanabranching).Basedonthecombinationofchannelplanformandbed sediment size, theExtendedRiver Typology (ERT) canprovide indirectinformationontheenergyconditions.Predominantlyconfined,alluvial,single-thread(from4 to 7), and alluvial braided (8, 9, 15), gravel-bed anabranching (10), wandering (11),pseudo-meandering (12, 16), and gravel-bed sinuous –meandering (13, 14) are normallyassociated to high or medium energy conditions. Sand- or silt-bed anastomosing andsinuous–meandering(from17to22)aretypicallow-energytypes.NotethattheERTisnotalwaysadiagnosticfeature,i.e.rivertypesfrom17to22arenotnecessarilyassociatedwithlow-energyconditions.Thismaybeespeciallythecasewherethebedrockiscomprisedofsand particles, inhighly impacted reaches, such aswhere there is an artificially imposedmorphology(e.g.,predominantlyartificialbedand/orheavilyengineered,stabilisedbanks),orincaseofdramaticchanneladjustments(e.g.,bedincision).Eventually,thismayresultin

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a typical low-energy ERT planform (i.e., from 17 to 22) but under medium-high energyconditions. During the application of the MQI, the fact that the observed planformmorphology is out of context should be recognised (see indicator F7 in Appendix 3 fordetails).Aparticularcaseoflow-energystreamsisrepresentedbyalluvialgroundwater-fedstreams.Thesestreamsarefedbygroundwaterspringsorbykarstsprings,andtheirflowis largelymaintained by contributions from groundwater during low flow periods (see for exampleBergandAllen,2007).

1.5 Structureandkeycomponentsoftheevaluationprocedure

The following aspects are considered for the assessment of themorphological quality ofriver reaches, and are consistent with CEN (2002) standards and WFD requirements: (i)continuity of river processes, including longitudinal and lateral continuity; (ii) channelmorphological conditions, including channel pattern, cross section configuration, and bedsubstrate;(iii)vegetation.Theseaspectsareanalyzedintermsofthreecomponents:(i)thegeomorphologicalfunctionalityofriverprocessesandforms;(ii)artificiality;and(iii)channeladjustments.Indicatorsofgeomorphic functionalityevaluatewhetherornot theprocessesandrelatedforms responsible for the correct functioning of the river are prevented or altered byartificialelementsorbychanneladjustments.Theseprocesses include,amongothers, thecontinuityofsedimentandwoodflux,bankerosion,periodic inundationofthefloodplain,morphological diversity in planform and cross section, themobility of bed sediment, andprocessesofinteractionwithvegetation.Indicators of artificiality assess the presence and frequency of artificial elements orinterventions,independentlyoftheireffectsonprocesses.Therefore,artificialelementsareaccounted for in twoways, i.e., based on their function or their effects as noted by thefunctionalityindicators(i.e.,aselementspreventingnaturalprocesses,forexample,abankprotection that prevents lateral erosion) and based on their presence and density (i.e.,artificialelementsthatarenotexpectedinunalteredrivers,independentlyoftheireffects).Some elements havemultiple effects on the various components of the evaluation (i.e.,functionality and artificiality), and apparent repeated evaluations are actually useful indiscerningtheimpactoftheseelementsonthedifferentcomponents.Finally, indicators of channel adjustments are included in the evaluation. Adjustmentscausedbyhumandisturbancescanshiftwithinafluvialsysteminspaceandtime,sothatanalterationinchannelformandprocessmayberelatedtodisturbancesthatoccurredinthepastand/orinadifferentlocationwithinthewatershed(SimonandRinaldi,2006).Channeladjustmentsfocusonrelativelyrecentmorphologicalchanges(i.e.,aboutthelast100years)thatareindicativeofasystemicinstabilityrelatedtohumanfactors.Infact,human-induceddisturbancesgreatlycompresstimescalesforchanneladjustments(e.g.,RinaldiandSimon,1998; Simon and Rinaldi, 2006). Channel changes that are not clearly related to humandisturbancesbutthatoccurredduringthistimeframe(e.g.,changesrelatedtolargefloods)mayalsoberecognisedbutarenotconsideredasanalteration.Tothisend,theinformationfrom indicators of artificiality is useful (e.g., intense sediment removal activity or thepresenceofdamsinthewatershedthatcouldbeinterpretedascausesofintensechanneladjustments). As notedpreviously, the historical river conditions (past 100 years) are not

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considered as a reference state but as a comparative situation to infer whether channeladjustmentshaveoccurredoverrecentdecades.Indicators of geomorphic functionality and channel adjustments can be considered as‘responseindicators’,whereas indicatorsofartificialityare ‘pressure indicators’. Includingboth ‘response’ and ‘pressure’ indicators provides a basis for understanding causes ofcurrent river conditions. The same type of pressuremay result in different responses fordifferentrivers,andforthisreason,theartificialityindicatorsidentifythepotentialelementsof alteration, whereas the functionality and channel adjustment indicators assess thegeomorphic responses (effects) to these disturbances, including past off-site impacts andadjustments. This synergic use of the different components of the assessment and theirmutual feedbacks promotes a sound understanding of the river conditions and causes ofalteration,whichcanbeusedtoselecttheappropriatemanagementactions.Although identification of the causes of channel adjustments may not always bestraightforward, a simplified analysis of past evolution, like the one carried out in theevaluationprocedure,allowschangesthatarestrictlyrelatedtohumaninterventionstobedistinguished from those that reflect the natural tendencies of the channel (e.g., naturalevolutionarytrajectoriesrelatedtoclimaticvariationsorchannelresponsetolargefloods).Referenceconditionsarenotdefinedintermsofaprecisechannelconfigurationorasetofchannel characteristics expected in a given reach, because rivers are dynamic and followcomplex evolutionary trajectories, changing their morphology through time. Therefore,referenceconditionsaredefinedconsideringthepreviousthreecomponents(functionality,artificiality, channel adjustments). For functionality, the reference conditions are givenbythe channel form and processes that are expected for the morphological type underexamination. For artificiality, reference conditions are indicated by the absence or onlyslightpresenceofhumanintervention intermsofflowandsedimentregulation,hydraulicstructures, and river maintenance activities. If elements of artificiality exist, they shouldproduce only small to negligible effects on the channelmorphology and river processes.Finally, concerning channel adjustments in relation to reference conditions, the channelcouldbeaggradingor incising inthelongterm(e.g.thelast100-200years),butnotgoingthroughmajorchangesofchannelmorphologycausedbyhumanfactors.Theoverallevaluationiscarriedoutbymakingasynergicuseoftwotypesofmethods:GISanalysis (using available databases and remotely sensed data such as aerial photos andLiDARDTMs)andfieldsurveys.The spatial scale of application is a river reach, as identified during the initial phase ofsegmentation.However,alterationsofflowandsedimentdischargerequireinformationatthe segment and at the catchment scale on the types of interventions affecting thesevariables(i.e.,dams,checkdams,weirs,etc.).GISanalysisiscarriedoutatthereachscale,whilethefieldsurveyisfocussedonrepresentativesubreaches(or ‘sites’). Intermsoftheimplicationsformanagement,anassessmentoftheentireriverisadvisabletoavoidmissingthepotentialcausesofsystemicriver instabilityandtoenableacause-and-effectbasisforrivermanagement.As alreadyexplained in section1.1, theMQI assessment includesonly thosehydrologicalaspects related to alterations of channel-forming discharges, i.e., those having significanteffectsongeomorphologicalprocesses.Theoverallchangesinthehydrologicregimeshould

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beanalysedseparatelybycalculatingaspecificindexofhydrologicalalteration(e.g.,IARIorIAHRIS).In this updated version of the MQI, a new tool has been developed, the Hydro-MorphologicalQualityIndex(HMQI),andhasbeenintegratedbyaddingthesub-indicator(A1H)concerningthealterationofflows,whetherornoteffectsonchannelmorphologyare(as yet) observed. The MQI can continue to be applied alone to assess morphologicalconditions, whereas the HMQI can now provide an assessment of the overallhydromorphological(i.e.,hydrologicalandmorphological)conditions.

1.6 Indicators

The complete set of indicators (28) canbe schematically representedby cross-tabulatingtheaspects(inrows)andcomponents(incolumns)describedintheprevioussection(Table1.7).During the segmentation phase, three classes based on channel confinement weredifferentiated:(i)confinedchannels(hereafter‘C’);(ii)partlyconfinedchannels(hereafter‘PC’); and (iii) unconfined channels (hereafter ‘U’). At this stage, two procedures weredevelopedgiven that thesame indicatorscanbeused forpartlyconfinedandunconfinedchannels.Thisimpliesthatsomedifferencesexistinthenumberandtypeofindicatorsforeachofthesetwoprocedures,assomeoftheindicatorsarespecificforconfinedchannelswhiletheyarenotsuitableforpartlyconfinedandunconfined,andviceversa.Forexample,thepresenceandextensionofamodernfloodplainisnotconsideredrelevantinthecaseofconfinedchannels,whileitisanimportantfeatureforbothpartlyconfinedandunconfinedchannels.A summary of indicators, with assessed parameters, assessmentmethods, and ranges ofapplication, is reported in Table 1.8, while a detailed description of each indicator isreportedintheGuidetotheCompilationoftheMQIEvaluationForms(Appendix3).Table1.7Listof indicatorsasafunctionofthemainaspects(continuity,morphology,vegetation)andcomponentsofassessment(functionality,artificiality,channeladjustments). Functionality Artificiality ChanneladjustmentsContinuity

-longitudinal

F1

A1,A2,A3,A4,A5

-lateral F2,F3,F4,F5 A6,A7 Morphology

-channelpattern

F6,F7,F8

A8(A6)

CA1

-crosssection F9

(A4,A9,A10) CA2,CA3

-bedsubstrate F10,F11

A9,A10,A11

Vegetation

F12,F13 A12

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Table1.8Definition,assessedparameters,assessmentmethods,andrangesofapplicationofeachindicator.(modifiedfromRinaldietal.,2013).Indicatorsandassessedparameters Assessmentmethods RangesofapplicationF1–Longitudinalcontinuityinsedimentandwoodflux

Remotesensingand/ordatabaseofinterventions:identificationofcrossingstructures;fieldsurvey:visualassessmentofpartialorcompleteinterception(qualitative)

Allrivertypes

Presenceofcrossingstructures(weirs,check-dams,bridges,etc)thatpotentiallymayalternaturalfluxofsedimentandwoodalongthereachF2–Presenceofamodernfloodplain Remotesensing–GIS:measurementofwidth

andlongitudinallength(quantitative);fieldsurvey:identification/checkingofmodernfloodplain(qualitative)

PC–U;notevaluatedinthecaseofmountainstreamsalongsteep(>3%slope)alluvialfans

Widthandlongitudinallengthofamodernfloodplain

F3–Hillslope–rivercorridorconnectivity Remotesensing–GIS:identificationandmeasurementoflengthofdisconnectingelements(quantitative);fieldsurvey:checkingdisconnectingelements(qualitative)

CPresenceandlengthofelementsofdisconnection(e.g.,roads)withinabuffer50-mwideforeachsideoftheriverF4–Processesofbankretreat Remotesensingand/orfieldsurvey:

identificationoferodingbanks(qualitative)PC–U;notevaluatedinthecaseofLow-EnergyERTtypesfrom17to22

Presence/absenceofretreatingbanks

F5–Presenceofapotentiallyerodiblecorridor Remotesensing–GIS:measurementofwidthandlongitudinallength(quantitative)

PC–UWidthandlongitudinallengthofanerodiblecorridor,i.e.,areawithoutrelevantstructures(e.g.,bankprotections,levées)orinfrastructure(e.g.,houses,roads)F6–Bedconfiguration–valleyslope Topographicmaps:meanvalleyslope

(quantitative);fieldsurvey:identificationofbedconfiguration(qualitative)

single-thread,alluvialC(ERTtypesfrom4to7),exceptthecaseofdeepstreamswhenobservationofthebedisnotpossible

Identificationofbedconfiguration(i.e.,cascade,steppool,etc.)incaseswheretransversebedstructuresarepresentandincomparisonwiththeexpectedbedconfigurationbasedonvalleyslopeF7–Planformpattern Remotesensing–GIS:identificationand

measurementoflengthofalteredportions(quantitative);fieldsurvey:identification/checking(qualitative)

PC–U;ConfinedERTtypes8,9,10,11,15,19,22Percentageofthereachlengthwithaltered

planformandgeomorphicunits

F8–Presenceoftypicalfluviallandformsinthefloodplain

Remotesensingand/orfieldsurvey:identificationandcheckingoffluvialforms(qualitative)

PC–U

Presence/absenceofappropriatelandformsinthefloodplain(e.g.,oxbowlakes,secondarychannels,etc.)F9–Variabilityofthecrosssection Fieldsurvey:identification/checking

(qualitative);remotesensing–GIS:identificationandmeasurementoflengthofalteredportions(quantitative)

AlltypesPercentageofthereachlengthwithalterationofthenaturalheterogeneityofthecrosssectionthatisexpectedforthatrivertypeandiscausedbyhumanfactorsF10–Structureofthechannelbed Fieldsurvey:visualassessment(qualitative)

Alltypes,exceptthecaseofdeepchannelswhenobservationofthebedisnotpossible

Presence/absenceofalterationsofbedsediment(armouring,clogging,bedrockoutcrops,bedrevetments)F11–Presenceofin-channellargewood Fieldsurvey:visualassessment(qualitative) Alltypes;notevaluatedabove

thetree-lineandinstreamswithanaturalabsenceofwoodyriparianvegetation

Presence/absenceoflargewood

F12–Widthoffunctionalvegetation Remotesensing–GIS:identificationandmeasurementofmeanwidthoffunctionalvegetation(quantitative)

Alltypes;notevaluatedabovethetree-lineandinstreamswithanaturalabsenceofriparianvegetation

Meanwidth(orarealextension)offunctionalriparianvegetationinthefluvialcorridorpotentiallyconnectedtochannelprocesses

F13–Linearextensionoffunctionalvegetation Remotesensing–GIS:identificationandmeasurementoflongitudinallengthoffunctionalvegetation(quantitative)

Alltypes;notevaluatedabovethetree-lineandinstreamswithanaturalabsenceofriparianvegetation

Longitudinallengthoffunctionalriparianvegetationalongthebankswithdirectconnectiontothechannel

A1–Upstreamalterationofflows Hydrologicaldata:evaluationofreduced/increaseddischargecausedbyinterventions(quantitative).Intheabsenceofavailabledata,theassessmentisbasedonthepresenceofflowinterventionanditsuse(qualitative)

AlltypesAmountofchangesindischargecausedbyinterventionsupstream(dams,diversions,spillways,retentionbasins,etc.)

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A2–Upstreamalterationofsedimentdischarges Remotesensing–GISand/ordatabaseofinterventions:identificationofstructuresandrelativedrainagearea(quantitative)

AlltypesPresence,type,andlocation(drainagearea)ofrelevantstructuresresponsibleforbedloadinterception(dams,check-dams,weirs)

A3–Alterationofflowsinthereach SeeA1 AlltypesAmountofalterationsofdischargecausedbyinterventionswithinthereach

A4–Alterationofsedimentdischargeinthereach Remotesensing–GISand/ordatabaseofinterventions:identificationandnumberofstructures(quantitative)

AlltypesTypeandspatialdensityofstructuresinterceptingbedload(checkdams,weirs)alongthereach

A5–Crossingstructures Remotesensing–GISand/ordatabaseofinterventions:identificationandnumberofstructures(quantitative)

AlltypesSpatialdensityofcrossingstructures(bridges,fords,culverts)A6–Bankprotections Remotesensing–GISand/ordatabaseof

interventions:lengthofstructures(quantitative)

AlltypesLengthofprotectedbanks(walls,rip-raps,gabions,groynes,bioengineeringmeasures)

A7–Artificiallevées Remotesensing–GISand/ordatabaseofinterventions:lengthanddistanceofstructures(quantitative)

PC–ULengthanddistancefromthechannelofartificiallevéesA8–Artificialchangesofrivercourse Historical/bibliographicinformationand/or

databaseofinterventions(quantitative)PC–U

Percentageofthereachlengthwithdocumentedartificialmodificationsoftherivercourse(meandercutoff,relocationofriverchannel,etc.)A9–Otherbedstabilizationstructures Remotesensing–GISand/ordatabaseof

interventions:identification,numberorlengthofstructures(quantitative)

AlltypesPresence,spatialdensityandtypologyofotherbed-stabilizingstructures(sills,ramps)andrevetmentsA10–Sedimentremoval Databaseofinterventionsand/orinformation

availablebypublicagencies;fieldsurveyand/orremotesensing:indirectevidence(qualitative)

Alltypes;notevaluatedinthecaseofERTtype1Existenceandrelativeintensityofpastsediment

miningactivity(overthelast100years,withaparticularfocusonthelast20years)A11–Woodremoval Databaseofinterventionsand/orinformation

availablebypublicagencies;fieldsurvey:additionalevidence(qualitative)

Alltypes;notevaluatedabovethetree-lineandinstreamswithnaturalabsenceofriparianvegetation

Existenceandrelativeintensity(partialortotal)ofin-channelwoodremovalduringthelast20years

A12–Vegetationmanagement Databaseofinterventionsand/orinformationavailablebypublicagencies;fieldsurvey:additionalevidence(qualitative)

Alltypes;notevaluatedabovethetree-lineandinstreamswithnaturalabsenceofriparianvegetation

Existenceandrelativeintensity(selectiveortotal)ofvegetationcutsduringthelast20years

CA1–Adjustmentsinchannelpattern Remotesensing–GIS(quantitative) Alltypes;evaluatedonlyforsufficientlylargechannelsChangesinchannelpatternfrom1930sto1960s

basedonchangesinsinuosity,braiding,andanastomosingindicesCA2–Adjustmentsinchannelwidth Remotesensing–GIS(quantitative) Alltypes;evaluatedonlyfor

sufficientlylargechannelsChangesinchannelwidthfrom1930sto1960sCA3–Bed-leveladjustments Crosssections/longitudinalprofiles(if

available);fieldsurvey:evidenceofincisionoraggradation(qualitative/quantitative)

Alltypes;evaluatedincasefieldevidenceorinformationisavailable

Bed-levelchangesoverthelast100years

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1.7 Classesandscoresoftheindicators

The classes and corresponding scores of the indicators are briefly illustrated below andlisted in Tables 1.9, 1.10, and 1.11. As previously mentioned, the scoring system wasdevelopedusingtheexpertjudgementoftheauthors,implyingthatthescoresassignedtoeach indicatorandthe limitsamongclassesarearbitrary.Scoresandclassesweredefinedand subsequently improvedbasedon the results of a testing phase (Rinaldi et al., 2013).Scores have remained unchanged in this extended version, in order to ensure datacomparabilitywhenappliedtodifferentEuropeancountries.Threeclassesaregenerallydefinedforeachindicator(exceptforalimitednumberwithtwoclassesormorethanthreeclasses):(A)undisturbedconditionsornegligiblealterations;(B)intermediatealterations;(C)veryalteredconditions.For each indicator, we started by defining reference conditions for that indicator,correspondingtotheabsenceornegligiblepresenceofalterations(classA),andavalueof0isassignedtothisclass.Fortheindicatorsoffunctionality,ascoreof2to3isassignedtotheintermediateclassofalteration (classB),andascoreof5 to6 toclassC (highestalteration),dependingontherelative importanceattributed toeach indicator. For some indicators (e.g.,F2 andF10), afourthclassisaddedtobetterhighlightthedifferentlevelsofalteration.Asimilarapproachandscoringisadoptedfortheindicatorsofartificiality.ForindicatorsA2(upstream alteration of sediment discharges) andA9 (other bed stabilization structures),morethanthreeclassesaredefinedtoaccountforalargenumberofcases,andamaximumscoreof12isassignedtoclassC2ofA2(presenceofadamattheupstreamboundaryofthereach)becausethisisconsideredaverystrongelementofartificiality.Concerning the indicators of channel adjustments, the first two (CA1 and CA2, i.e.adjustmentsinchannelpatternandchannelwidth,respectively)ascoreof3forclassBand6forclassCareassigned,whereasbed-leveladjustments(CA3)areconsideredtobemorerelevant,andsoafourthclass(C2)isdefinedwithascoreof12,toaccountforthecaseofdramaticbed-levelchanges(>6m).Forexample, insomeItalianrivers,verymarkedriverincision has occurred (up to 10-12m) in the recent past mostly as a response to gravelmining(SurianandRinaldi,2003).Anadditionalruleisdefinedforthecasesofanextremelydenseanddominantpresenceofartificialelementsalongthereach,suchastransversalstructures,bankprotections,levées,artificial changes of river course, bed revetments (indicators A4, A6, A7, A8, and A9,respectively).This rule is includedtoadequatelyrankriverreacheswithonlyasingleorafew types of artificial elements but that have a very large extent and/or density, heavilyaffecting the overall morphological conditions (e.g., completely embanked reaches inurbanized areas; steep mountain creeks with staircase-like sequences of grade-controlstructures).Withoutthis“extra-penalty”,theassignationofclassCtoonlyafewartificialityindicators would result in an underestimation of artificiality (and thus the concomitantoverestimation of morphological quality). To weight these cases more effectively, ratherthandefininganadditionalclass,anextrascoreof6or12isassignedandaddedonlytothenumeratorofEq.(1).

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Table1.9Indicatorsofgeomorphologicalfunctionality:descriptionofclassesanddefinitionofscores.Indicator Classes ScoreF1 A-absenceofalterationinthecontinuityofsedimentandwood 0

B-slightalteration(obstaclestothefluxbutwithnointerception) 3C-significantalteration(completeinterceptionofsedimentandwood) 5

F2 A-presenceofacontinuous(>66%ofthereach)andwidemodernfloodplain(>nW,wheren=1or2forwandering–braidedorforsinglethread-anabranchingchannels,respectively,andW=channelwidth)

0

B1-presenceofadiscontinuous(10÷66%)butwidemodernfloodplainor>66%butnarrow 3B2-presenceofadiscontinuous(10÷66%)andnarrowmodernfloodplain 2C-absenceofamodernfloodplainornegligiblepresence(≤10%ofanywidth) 5

F3

A-fullconnectivitybetweenhillslopesandrivercorridor(>90%) 0B-connectivityforasignificantportionofthereach(33÷90%) 3C-connectivityforasmallportionofthereach(≤33%) 5

F4 A-bankerosionoccursfor>10%andisdistributedalong>33%ofthereach 0B–bankerosionoccursfor≤10%,orfor>10%butconcentratedalong≤33%ofthereach,orsignificantpresence(>25%)oferodingbanksbymassfailures 2

C-completeabsence(≤2%)ofretreatingbanks,orwidespreadpresence(>50%)ofunstablebanksbymassfailures 3

F5 A-presenceofapotentiallyerodiblecorridor(EC)foralength>66%ofthereachandwide(>nW,wheren=1or2forwandering–braidedorforsinglethread-anabranchingchannels,respectively,andW=channelwidth)

0

B-presenceofanarrow(≤nW)potentiallyECfor>66%,orwidebutfor33÷66%ofthereach 2C-presenceofapotentiallyECofanywidthbutfor≤33%ofthereach 3

F6

A-bedformsconsistentwiththemeanvalleyslope 0B-bedformsnotconsistentwiththemeanvalleyslope 3C-completealterationofbedformsorthepresenceofanartificialbed 5

F7

A-absence(≤5%)ofalterationofthenaturalheterogeneityofgeomorphicunitsandchannelwidth 0B-alterationforalimitedportionofthereach(≤33%) 3C-consistentalterationforasignificantportionofthereach(>33%) 5

F8 A-presenceoffloodplainlandforms(oxbowlakes,secondarychannels,etc.) 0B-presenceoftracesoffloodplainlandforms(abandonedduringthelastdecades)butwithpossiblereactivation 2

C-completeabsenceoffloodplainlandforms 3F9 A-absence(≤5%)ofalterationofthecross-sectionnaturalheterogeneity 0

B-presenceofalterationforalimitedportionofthereach(≤33%) 3C-presenceofalterationforasignificantportionofthereach(>33%) 5

F10 A-naturalheterogeneityofbedsedimentsandnosignificantclogging 0B-evidentarmouring(PC–Uonly)orclogginginvariousportionsofthesite 2C1-evidentandwidespread(>90%)armouring(PC–Uonly)orclogging,orburial(≤50%ofthereach),oroccasionalsubstrateoutcrops(PC–Uonly) 5

C2-evidentburial(>50%),orwidespreadsubstrateoutcrops(>33%ofthereach)(PC–Uonly)orwidespreadsubstratealterationbybedrevetments(>33%ofthereach) 6

F11 A–significantpresenceoflargewoodalongthewholereach 0B-negligiblepresenceoflargewoodfor≤50%ofthereach 2C-negligiblepresenceoflargewoodfor>50%ofthereach 3

F12 A-wideconnectedfunctionalvegetation(PC-U:>nW,wheren=1or2forwandering–braidedorforsinglethread-anabranchingchannels,respectively,andW=channelwidth;C:>90%ofhillslopes,50mfromeachbank)

0

B-intermediatewidthofconnectedfunctionalvegetation(PC-U:0.5W÷nW;C:33÷90%ofhillslopes,50mfromeachbank) 2

C-narrowconnectedfunctionalvegetation(PC-U:≤0.5W;C:≤33%ofhillslopes,50mfromeachbank) 3

F13 A-linearextensionofriparianvegetation>90%ofmaximumavailablelength 0B-riparianvegetation33÷90% 3C-riparianvegetation≤33% 5

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Table1.10Indicatorsofartificiality:descriptionofclassesanddefinitionofscores.Indicator Classes ScoreA1M A-nosignificantalteration(≤10%)ofchannel-formingdischarges(returnintervalRIfrom1.5to10

years)andQwithreturninterval>10years 0

B-significantalteration(>10%)ofQwithreturninterval>10years 3C-significantalteration(>10%)ofchannel-formingdischarges 6

A2 A-absenceornegligiblepresenceofstructuresofinterceptionofsedimentfluxes 0B1-presenceofdamswithdrainagearea5÷33%,and/orweirsorcheckdamswithtotalinterceptionofbedloadanddrainageareas33÷66%,and/orweirsorcheckdamswithpartialornointerceptionofbedloadanddrainageareas>33%(plain/hillsareas)or>66%(mountainareas)

3

B2-presenceofdamsfordrainagearea33÷66%,and/orweirsorcheckdamswithtotalinterceptionofbedloadanddrainageareas>66% 6

C1-presenceofdamsfordrainagearea>66% 9C2-presenceofadamattheupstreamboundaryofthereach 12

A3 A-nosignificantalteration(≤10%)ofchannel-formingdischargesandQwithreturninterval>10years 0

B-significantalteration(>10%)ofQwithreturninterval>10years 3C-significantalteration(>10%)ofchannel-formingdischarges 6

A4 A-absenceofstructuresthatinterceptsedimentflux(dams,checkdams,weirs) 0B–channelswithS≤1%:consolidationcheckdamsand/orabstractionweirs(includinginstreamretentionbasins)≤1every1000m;steepchannels(S>1%):consolidationcheckdams/weirs≤1every200mand/oroneormoreopencheckdams(includinginstreamretentionbasins)

4

C-channelswithS≤1%:consolidationcheckdamsand/orabstractionweirs(includinginstreamretentionbasins)>1every1000m;steepchannels(S>1%):consolidationcheckdams>1every200mand/oroneormoreretentioncheckdamsOrpresenceofadamorartificialreservoiratthedownstreamboundary(anybedslope)

6

Wheretransversalstructures,includingbedsillsandramps(A9),are>1everyd1,add6Wheretransversalstructures,includingbedsillsandramps(A9),are>1everyd2,add12

d1=150mandd2=100minsteepchannels,d1=750mandd2=500minchannelswithS≤1%

A5 A-absenceofcrossingstructures(bridges,fordsculverts) 0B-presenceofsomecrossingstructure(≤1every1000monaverageinthereach) 2C-presenceofnumerouscrossingstructures(>1every1000monaverageinthereach) 3

A6 A-absenceorlocalizedpresenceofbankprotections(≤5%totallengthofthebanks) 0B-presenceofprotectionsfor≤33%totallengthofthebanks(sumofbothbanks) 3C-presenceofprotectionsfor>33%totallengthofthebanks(sumofbothbanks) 6

Forahighdensityofbankprotections(>50%)add6Foranextremelyhighdensityofbankprotections(>80%)add12

A7 A-levéesabsent,set-back,orpresentandincontact≤5%totallengthofthebanks 0B-mediumpresenceoflevéescloseand/orincontact(incontact≤50%banklength) 3C-highpresenceoflevéescloseand/orincontact(incontact>50%banklength) 6

Forahighdensityofbank-edgelevées(>66%)add6Foranextremelyhighdensityofbank-edgelevées(>80%)add12

A8

A-absenceofartificialchangesoftherivercourseinthepast(meanderscut-off,channeldiversions,etc.); 0

B-presenceofchangesfor≤10%ofthereachlength 2C-presenceofchangesfor>10%ofthereachlength 3

Inthecaseofhistoricaldrainageanddredgingworksfor>50%ofthereach(whenanadditionalscoreisnotalreadyappliedforA6and/orA7),add 6

Inthecaseofhistoricaldrainageanddredgingworksfor>80%ofthereach(whenanadditionalscoreisnotalreadyappliedforA6and/orA7),add12

A9 A-absenceofstructures(bedsills/ramps)andrevetments 0B-limitedpresenceofstructures(≤1everyn,wheren=200mformountainareas,n=1000mforplain/hillsareas)and/orrevetments(≤15%impermeableand/or≤25%permeable) 3

C1-presenceofmanystructures(>1everyn)and/orsignificantbedrevetments(≤33%impermeableand/or≤50%permeable) 6

C2-presenceofimpermeablebedrevetments>33%and/orpermeablerevetments>50% 8Forahighdensityofbedrevetment(impermeable>50%orpermeable>80%)add6

Foranextremelyhighdensityofbedrevetment(impermeable>80%)add12

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Table1.10(continued)Indicatorsofartificialityandchanneladjustments:descriptionofclassesanddefinitionofscores.

A10 PC–U:

A-absenceofrecent(last20years)andpast(overthelast100years)significantsedimentremovalactivities

0

B1–sedimentremovalactivityinthepastbutabsentduringthelast20years 3B2–recentsedimentremovalactivity(last20years)butabsentinthepast 4C–sedimentremovalactivityinboththepastandduringlast20years 6C:A-absenceofsignificantsedimentremovalactivitiesduringthelast20years

0

B-localizedsedimentremovalactivitiesduringthelast20years 3C-widespreadsedimentremovalactivitiesduringthelast20years 6

A11 A-absenceofremovalofwoodymaterialatleastduringthelast20years 0B–partialremovalofwoodymaterialduringthelast20years 2C-totalremovalofwoodymaterialduringthelast20years 5

A12 A-nocuttinginterventionsonriparianvegetation(last20years)andaquaticvegetation(last5years) 0

B-selectivecutsand/orclearcutsover≤50%ofthereach(last20years)andpartialornocuttingofaquaticvegetation(last5years),ornocuttingofriparianbutpartialortotalcuttingofaquaticvegetation

2

C-clearcutsover>50%ofthereach(last20years),orselectivecutsand/orclearcutsofriparianvegetation≤50%ofthereachbuttotalcuttingofaquaticvegetation(last5years)

5

CA1 A-absenceofchangesinchannelpatternsince1930s–1960s 0B-changetoasimilarchannelpatterntothatofthe1930s–1960s(PC–U)orchangeofchannelpatternfrom1930s–1960s(C) 3

C-changetoadifferentchannelpatternfromthatofthe1930s–1960s(onlyPC–U) 6CA2 A-absentorlimitedchanges(≤15%)since1930s–1960s 0

B-moderatechanges(15÷35%)fromthatofthe1930s–1960s(PC–U)orchanges>15%fromthatofthe1930s–1960s(C) 3

C-intensechanges(>35%)fromthatofthe1930s–1960s(onlyPC–U) 6CA3 A-negligiblebed-levelchanges(≤0.5m) 0

B-limitedormoderatebed-levelchanges(0.5÷3m) 4C1-intensebed-levelchanges(>3m) 8C2–veryintensebed-levelchanges(>6m)(onlyPC–U) 12

1.8 CalculationoftheMorphologicalQualityIndex(MQI)

A total score is computed as the sum of scores across all components and aspects. TheMorphologicalAlterationIndex(MAI)isfirstdefinedasfollows:

MAI=Stot/Smax (1)whereStotisthesumofthescores,andSmaxisthemaximumscorethatcouldbereachedwhenallappropriateindicatorsareinclassC.Therefore,MAIrangesfrom0(noalteration)to1(maximumalteration).TheMorphologicalQualityIndexisthendefinedas

MQI=1-MAI=1–Stot/Smax (2)Thisindexisthereforedirectlyproportionaltothequalityofthereachandinverselytothealterations,varyingfrom0(minimumquality)to1(maximumquality).According to this structure, reference conditions (i.e., class A for each indicator,corresponding to MQI = 1) are identified with the following: (i) the full functionality ofgeomorphic processes along the reach; (ii) the absenceor negligible presenceof artificialelementsalongthereachandtosomeextent(intermsofflowandsedimentfluxes)inthecatchment; and (iii) the absence of significant channel adjustments (configuration,width,bedelevation)overatemporalframeofabout100years.

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As previously mentioned, the overall assessment procedure is carried out by using twodifferent evaluation forms: one for confined channels, and one for partly confined andunconfined channels (see Appendices 1 and 2, respectively). An electronic format of theevaluationformsisavailableathttp://www.isprambiente.gov.it/pre_meteo/idro/idro.html,whichallowsautomaticcalculationoftheindicatorsoncetheinputvaluesareentered.The total score (Smax) can vary within each category (confined, partly confined andunconfined)dependingontherivertypeand/orthephysicalcontext.Forexample,indicatorF6 (bed morphology in single-thread confined channels) is not evaluated for bedrockstreams; or F10 (structure of the channel bed) is not applied in deep channelswhere itsevaluationisimpossible.Duringtheassessmentandthecompilationoftheevaluationforms,someindicatorsmaybeaffectedbya lackofdataor informationormay requirean interpretation that involvesacertaindegreeofsubjectivity.Tohelpinindicatinghowcertaintheuserfeelsconcerningtheanswer,adegreeofconfidence(low,medium,high)andasecond(alternative)choiceintheclassescanbeexpressed.Thisiscalculatedbytakingthescoresforthesecondchoice(withlowormediumconfidenceintheanswer),andobtainingarangeofvariabilityratherthanasinglefinalvalueoftheMQI.The three components (geomorphological functionality, artificiality, and channeladjustments)donothavethesameweightwithinthefinalscoreoftheMQI:artificialityhasthe highest weight on the overall scoring, followed by functionality and channeladjustments. This reflects the authors’ opinion that the knowledge of past channeladjustmentsisimportantbuthasaminorweightintheoverallscorecomparedtotheothertwo components. In other words, past conditions are important and may affect themorphologicalquality,buttheartificialconstraintsandthefunctioningofprocesses inthepresentconditionarethetwomaincomponentsoftheevaluation.The following classes of morphological quality were defined: (i) very good or high,0.85≤MQI≤1;(ii)good,0.7≤MQI<0.85;(iii)moderate,0.5≤MQI<0.7;(iv)poor,0.3≤MQI<0.5;(v)verypoororbad,0≤MQI<0.3.

Additionally,theMQIcanbedividedintoitsvariouscomponents,andaseriesofsub-indicescanbecalculated(seeSub-indicesinAppendix3).

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1.9 ApplicationoftheMQI

ThissectiondetailssomepracticalinformationconcerningtheapplicationoftheMQI.

1.9.1 ExpertiseTheapplicationof theMQI shouldbecarriedoutbypeoplewithappropriatebackgroundknowledgeoftheunderlyingprinciplesinfluvialgeomorphologyaswellasbeingsufficientlytrained. Similarly to other fields of river sciences (e.g., freshwater biology), applicationwithout the necessary background and skills could seriously affect the success of theassessment.

1.9.2 WorkingphasesandtimerequiredThe sequence ofworking phases is summarised as follows,with specific reference to theassessmentphase,i.e.theapplicationoftheMQItoagivendelimitedreach.1.CollectionofexistingmaterialItisassumedthatthegeneralsettingandsegmentationphasehasalreadybeencarriedout.Shouldsegmentationnotbeavailable,aminimumdelineationcanbeachievedonlyforthespecific portionor reachunder investigation. Thiswill require the collectionof additionalmaterial(seesection1.3).Oncethereachdelineationhasbeenestablished,thisphasewillfocusoncollectingdataandinformationmainlyatthereachscale,including:(i)themostrecentremotelysensedimages(aerialphotosorsatelliteimageswithsufficientlyhighresolution)representingthecurrentriverconditions;(ii)historicalaerialphotographs(betweenaboutthe1930sand1960s);(iii)amap layerof interventions (whenavailable), includingexisting informationon sedimentand vegetation management by public agencies. Information on relevant structuresresponsibleforthealterationofflowsand/orbedloadinterceptionisnecessaryforthesub-catchmentupstreamfromthereach.2.Preliminaryremotesensing-GISanalysisDuring this phase, the most recent remotely sensed images are analysed, and somepreliminaryGISanalysisisperformed.Forexample,theboundariesoftherivercorridor(inthecaseofanunconfinedorpartlyconfinedreach)andthechannelmarginsareidentified,andsomeindicatorscanundergopreliminaryassessmentorsometentativehypothesescanbemadebeforethefieldsurvey(e.g.,bankerosion,potentiallyerodiblecorridor,planformpattern,widthandlinearextensionoffunctionalvegetation,etc.).Thiswillaidinidentifyingcritical points and prioritising locations to visit during the field survey (see next step).Measurement of channel width in contemporary and historical conditions (the latterevaluatedonlyinthecaseofsufficiently largerivers)canbecarriedoutduringthisphase:this may require georeferencing of aerial photographs and digitising channel margins.Duringthisandthefollowingphase,thehardcopyoftheEvaluationFormscanbeused.3.FieldsurveyIt is important, if theresultsof thefieldsurveyaretobeoptimized, that itaddressesandchecksthecriticalaspects identifiedduringthepreviousphase.Furthermore,thisphase isstrictlynecessaryforaseriesofindicatorsrequiringfieldobservationand/ormeasurement(e.g., presence and extension of a modern floodplain, structure of the channel bed,presenceofin-channellargewood,etc.).Ifamaplayerofinterventionsisavailable,thiswill

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facilitate and minimize the fieldwork. Therefore, the field survey should possibly beprecededbythedevelopmentofadetailedplanoftheareastobevisited.4.FinalizingGISanalysisOncethecriticalaspectsoftheevaluationhavebeenresolvedbymeansofthefieldsurvey,theGIS analysis and themeasurementofquantitativeparameters canbe finalisedduringthisfinalphase.AswellascompletingthehardcopyoftheEvaluationForms,theelectronicformatcanbecompiledduringthisfinalphase.

Some additional aspects to be considered during the application for the MQI are thefollowing.

PeriodoftheyearforcarryingoutthefieldsurveyTherearenospecificrequirementsorconstraintsonthetimeofyeartocarryoutthefieldsurvey.Theonlyrecommendationistoavoidperiodsofhighflowevents,forobvioussafetyreasons, and because this would create unfavourable conditions for carrying out fieldobservations, as most of the channel bed would be submerged. The assessment is notprecluded during excessively low flow (or dry) periods. It is important to note that theassessment concerns the entire stream channel and river corridor, and not only itssubmergedportion.

TimingoftheMQIassessmentTheprocedure should not be applied shortly after a large flood (e.g., floodwith a returnperiod>10-20years).Theeffectsofsucheventscouldstronglyinfluencetheinterpretationof forms and processes. In such cases, the application of theMQI some years after theoccurrenceofthefloodisadvisable.It is important to note that the channel delimitation is carriedout using themost recentremotesensing imagesselectedfortheMQIapplication.Duringtheexecutionof thefieldsurvey, some channelmodificationdue to erosionor depositionmaybeobserved (this isverylikelytobethecaseindynamicstreams).Insuchcircumstances,however,theoperatorshould notmake anymodification to the channel boundaries (or other natural elements)becausethesearenotrelevantfortheMQIresult.TheevaluationofindicatorsbasedonGISmeasurements, therefore, refers to the date of the remote sensing images. Fieldobservationsareusedtoverifyandintegratethoseaspectswhichcannotbedeterminedbyremotesensing,furthertoevaluatingthoseindicatorswhichcanbeexclusivelyassessedinthefield.Concerningartificiality,fieldobservationscanprovidesomeupdatedinformationregarding interventionsthatwasnotavailable fromexistingmap layers.TheseneedtobeconsideredsincetheyarerelevantfortheMQIresult.Insummary,theMQIassessmentcannotbereferredtoaprecisedate(giventhatitisnotafieldsamplingmethod),butitrefers,rather,toanintervaloftimerangingfromthedateoftheimagesusedfortheanalysisandthedateofthefieldsurvey.

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TimerequiredfortheapplicationoftheMQIAspreviouslyemphasised,theMQIisnotjustafieldsamplingmethodologyandsocannotbe realised in only a fewhours of fieldwork.Quantification of the time required for theapplicationoftheMQIisnotstraightforwardasitdependsonaseriesoffactors,mainly:(i)thecompetence, training level,andexperienceof theoperator; (ii) theavailabilityofdataandotherinformation(e.g.,theexistenceofamaplayerofinterventionsandmanagementpracticeswillsignificantlyreducethetime).Thetimerequiredforanapplicationtoasinglereachalsodependsonthenumberofreachesofthesamesegmentorriverbeingassessed.Application to various reacheswill generally optimise thework and reduce the unit timerequired foreach reach: somestepscarriedout for thewhole segment/rivermay requireabout the same timeas foreachsingle reach.With reference to the fourworkingphasesdescribedearlier,thefollowingcommentscanbemade:1.Collectionofexistingmaterial.Thisisextremelyvariableanddependsconsiderablyonthedataandmaterial that isalreadyavailablebefore starting theassessment. In somecases,whenall thematerial isalreadyavailable,onlyasmallamountoftime isrequired.Shouldthe reach delineation need to be carried out, this will significantly increase the requiredtime,assomeparameters(confinementdegree,sinuosityindex,etc.)needtobemeasuredtodefinetheconfinementclassandtherivertype.2.Preliminaryremotesensing-GISanalysis.Dependingontheriverchanneltypeandsize(forexample, small confined streamsvs. largeunconfined rivers) thisphasecan requireatimeapproximatelyrangingfromafewhourstooneday.3.Fieldsurvey.Timerequiredforthefieldsurveyiscommonlyoneday.Thismaybereduced(to a minimum of half a day, i.e. two reaches per day) in the case of simple, relativelyuniformreaches.4. Finalizing GIS analysis. This phase is also variable, depending on the complexity oruniformity of the reach, but a maximum of one day is likely to be needed to preciselyquantify all the variables required to estimate the indicators, also allowing for theapplicationoftheMQIm.

1.9.3 RangesofapplicationThe MQI evaluation can be applied to any natural (sensu WFD) river water body. Thefollowingrangesofapplicationand/orlimitationscanbeconsidered:-Itcanbeappliedtostronglyartificialreaches,e.g.partiallyorcompletelyfixedreachesinurbanareas.-Itisnotapplicabletoartificialwaterbodies,lakes,orreservoirs.- It is not applicable to transitional water bodies (near the river mouth) as they areinfluencedbytidalandcoastalprocesses.

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2 Integratedtools:HMQIandMQIm

Following theMQI, two integrated tools have been developed for different contexts andapplications.TheHydro-MorphologicalQualityIndex(HMQI)isanextensionoftheMQIwiththe inclusion of an additional hydrological indicator, allowing for an assessment of theoverall hydrological and morphological conditions. The Morphological Quality Index formonitoring (MQIm), has been specifically designed to assess the environmental impactassessmentofinterventions,includingbothfloodmitigationandrestorationactions.

2.1 TheHydro-MorphologicalQualityIndex(HMQI)

TheHydro-Morphological Quality Index (HMQI) is an extension of theMQI designed toassess the overall hydromorphological conditions of a stream reach as envisaged by theWFD.It includes all the same indicators of theMQI, with the addition of a sub-indicator (A1H)concerning the upstream alteration of flows with potentially relevant effects on channelmorphology(seeAppendixfordetails).TheadditionalscoreoftheA1Hindicator(dependingontheclass,fromAtoC)isthenaddedtothesumoftheMQIscores(Stot),providingtheHydro-MorphologicalQualityIndex(HMQI)definedinthesamewayoftheMQI,i.e.:

HMQI=1–Stot/Smax (3)

where Smax remains the same of the MQI (i.e., the A1H score is added only to thenumeratoroftheequation).Similarly to theMQI, the following classes of the overall hydro-morphological quality aredefined: (i) very good or high, 0.85≤HMQI≤1; (ii) good, 0.7≤HMQI<0.85; (iii) moderate,0.5≤HMQI<0.7;(iv)poor,0.3≤HMQI<0.5;(v)verypoororbad,0≤HMQI<0.3.

2.2 TheMorphologicalQualityIndexformonitoring(MQIm)

2.2.1 IntroductionTheMorphologicalQuality Index (MQI)wasmainlydesigned toassess theoverall currentmorphological conditionsofa streamreach (i.e., a relativelyhomogeneousportionof theriverwitha lengthof theorderofsomekm),reflectingalterationsovera longtimescale.Therefore, the MQI may not be suitable for monitoring changes of channel conditionsoccurring ina shortperiodof timeand/or in smallportionsof the reach (e.g.,due to theremovalofabankprotectionstructure).To address this limitation, a new index, named the Morphological Quality Index formonitoring(MQIm),hasspecificallybeendesignedtotakeintoaccountsmallchanges(e.g.relative to small portions of a reach) and short time scales (i.e., a few years). Therefore,MQIm is particularly suitable for the environmental impact assessment of interventions,includingbothfloodmitigationandrestorationactions.This section presents this new tool and shows typical ranges of its application in rivermonitoring,managementandrestoration.

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2.2.2 CharacteristicsoftheMQImanddifferenceswiththeMQITheneedtoadoptanewprocedureformonitoringmorphologicalqualityderivesfromtheinvestigated spatial and temporal scales, which are different from the previous phase ofassessmentandclassificationofthecurrentmorphologicalstate.Concerningthetemporalscale, the MQI evaluates the overall morphological current conditions deriving frommodificationswhichhaveoccurredoverthe last50-100years.TheMQImisaspecifictoolfor monitoring changes in morphological quality over a time scale of a few years, forexample after the implementation of an intervention which could have enhanced ordegradedthemorphologicalconditions.ThemaindifferencesbetweenMQIandMQImaresummarisedinTable2.1andarebrieflyasfollows:(1)TheMQIisatoolfortheevaluation,classification,andmonitoringofthemorphologicalstate (i.e., good,poor, etc.). TheMQIm is a tool for specificallymonitoringmorphologicalconditions in the short term, i.e. to evaluate the tendency of morphological conditions(enhancementordeterioration).(2) The MQI scores are based on discrete classes, whereas the scores of many MQImindicatorsarebasedoncontinuousmathematicalfunctions.(3)Asaconsequenceofthepreviouspoint,MQImismoresensitivetochangesoccurringatatemporalscaleofafewyears.(4) Although the MQI indicators of channel adjustments (CA1, CA2, and CA3) should bemonitored,theyarenotexplicitly includedinthecalculationoftheMQIm.This isbecausechannel adjustments that occurred in the past are necessary for evaluating channelinstability in the MQI, whereas a recent, short term change cannot be interpreted andquantifiedwiththesamecriterion.Infact,currenttrendsofadjustmentmustbesetinthecontext of the evolutionary trajectory of changes and cannot easily be quantified for thepurposesoftheMQImcalculation.Channeladjustmentsarehowever indirectlytaken intoaccountbysomeoftheindicatorsoffunctionality.Forexample,inthecaseofariverreachchanging from single-thread to braided as a response to bank protection removal,adjustmentofchannelpatternisnotquantifiedbytheindicatorCA1 intheMQIm,butthegeomorphological functionality (e.g., indicatorF7)mustbe interpretedaccounting for thisadjustmenttowardsmorenaturalconditions.Table2.1MaindifferencesbetweenMQIandMQIm. Aim Temporalscale Scores ApplicationsMQI Assessment,classification

andmonitoringofthecurrentmorphologicalstate

50–100years Discreteclasses Tool toevaluatemorphologicalalterations compared toundisturbedconditions

MQIm Monitoringofmorphologicalconditionsintheshortterm

5–10years Continuousfunctions anddiscreteclasses

Tool to evaluate changes ofmorphological quality in theshortterm

2.2.3 ScoringsystemandmathematicalfunctionsIndicators based on presence/absence criteria and/or predominantly based on fieldobservations and interpretations are maintained in the format used forMQI, whereas aseries of mathematical functions are defined for those indicators based on quantitative

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parameters (e.g., percentage of altered reach, number of artificial structures, etc.) (Table2.2).Table2.2Listofindicatorsforwhichthescoresaredefinedbymathematicalfunctions.

Functionality ArtificialityF2,F3,F5,F6,F7,F9,F12,F13 A2,A4,A5,A6,A7,A8,A9,A12

MathematicalfunctionsfortheindicatorsreportedinTable2.2havebeendefinedonthebasisofthefollowingcriteria(Figure2.1):(1) Linear “upper” and “lower” interpolating functions are first defined, based on thehistogramofdiscreteclassesusedfortheMQI.(2)TheMQImfunctionisobtainedbyaseriesofsegmentsequidistantfromtheupperandlowerinterpolatingfunctions.Concerningthelastdiscreteclass(ontherightofFig.2.1),asegmentparalleltothelowerinterpolatingfunctionisassumed.SimilarlytotheMQI,theMorphologicalQualityIndexformonitoring(MQIm)isdefinedas:

MQIm=1–Stot/Smax (4)

whereStotisthesumofthescores,andSmaxisthemaximumscorethatcouldbereachedwhenall indicatorsassumethemaximumpossiblescore.NotethatthepossiblemaximumscoreforeachindicatorishigherthaninthecaseofMQI,ascanbeobservedinFigure2.1,thereforeSmaxisalsohigher.ThisimpliesthatthevaluesofMQIandMQImarenotdirectlycomparable.FortheapplicationoftheMQIm,itispossibletousethesamefieldevaluationformsasfortheMQIbyusingthespacebelowtheindicatorswithmathematicalfunctionstoreportthespecific values of the parameters needed for the calculation of the indicator. Then, theelectronicformatoftheMQImevaluationformsisavailableathttp://wiki.reformrivers.eu,allowingautomaticcalculationoftheindicatorsoncetheinputvalueshavebeentypedin.

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Figure 2.1 Procedure for the definition of themathematical function of aMQIm indicator deriving from the discreteclassesofthesameMQIindicator.

2.2.4 Evaluationprocedures,limitationsandapplicationsTheMQIandMQImevaluatemorphologicalqualityatadifferenttemporalscale,thereforetheycanbeconsideredascomplementaryratherthanalternativeassessments.TheMQImprovidesanindicationonthetrendofmorphologicalqualityintheshortterm.Tothisend,thevalueofMQImrelatedtoasinglesituationisnotmeaningful,butthedifferenceoftheindex between two assessments is particularly relevant, indicating a tendency to anenhancementordeteriorationofthemorphologicalquality.For the previous reasons, it is important to integrate theMQIm assessment with a newevaluationoftheMQI,thusprovidinginformationonapossiblechangeintheoverallstateofthereach,inadditiontoitstendency.Tothisend,notethatthenewcalculationofMQIwillbeavailableoncealltheinformationfortheMQImisavailable,withthesoleadditionoftheindicatorsofchanneladjustments.For the application of both theMQI andMQIm, the following two specific cases requireparticularcaution:(1)Riverrestorationinterventions.Inthecaseoftheimplementationofarestorationprojectinvolvingasignificantportionofthereach,it isadvisabletoconducttheassessmentsometimeafter the intervention, for example after some formative floodevent. In any case, aperiod of at least 5 years subsequent to the intervention in advisable. This is particularlytrue in the case of interventions of “morphological reconstruction”, in which case it isnecessaryfortherivertobeabletoadapttothenewconditions.(2)Largefloodevents.Inthecaseoftheoccurrenceofafloodeventofhighintensity(e.g.,flood with a return period > 10-20 years), particular attention must be paid to theinterpretation of any eventualmorphological changes. In fact, the effects of such events

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could strongly influence the interpretation of forms and processes. In such cases, theapplicationoftheMQIandMQImsomeyearsaftertheoccurrenceofthefloodisadvisable.Some main applications of the MQIm for monitoring morphological conditions are asfollows:(1)WFD monitoring. The MQIm can be adopted, in integration with the MQI, for WFDmonitoring,withaspatio-temporalfrequencythatcanbedefineddependingonthetypeofmonitoring(surveillance,operative,investigative).(2) Evaluation of the impact of new interventions. The MQIm is particularly suitable forevaluating the possible impacts of an intervention (including river restoration projects)duringthedesignstagegiventhatthisindexissensitivetotheimpactofinterventionsevenof a limited length compared to the reach length. To this purpose, an ante operamassessment, evaluating the current conditions, can be followed by a post operamassessment, making assumptions concerning the expected changes in some of themorphologicalindicatorsinresponsetotheintervention.Thecomparisonofanteandpostoperam assessment will indicate the tendency to improvement or deterioration of theproject.

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Rinaldi, M., Gurnell, A.M., Gonzalez del Tanago, M., Bussettini, M., Hendriks, D., 2016.Classification of river morphology and hydrology to support management andrestoration.AquaticSciences,doi:10.1007/s00027-015-0438-z,78(1),17-33.

Simon,A.,Rinaldi,M.,2006.Disturbance,streamincision,andchannelevolution:therolesofexcesstransportcapacityandboundarymaterials incontrollingchannelresponse.Geomorphology79,361-383.

Sneath, P.H.A., Snokal, R.R., 1973. Numerical Taxonomy: The Principles and Practice ofNumericalClassification.W.H.Freeman,SanFrancisco,CA,USA,573pp.

Surian,N.,Rinaldi,M.,2003.MorphologicalresponsetoriverengineeringandmanagementinalluvialchannelsinItaly.Geomorphology50(4),307-326.

Surian,N.,Rinaldi,M.,Pellegrini,L.,Audisio,C.,Maraga,F.,Teruggi,L.B.,Turitto,O.,Ziliani,L.,2009.ChanneladjustmentsinnorthernandcentralItalyoverthelast200years.In:James, L.A., Rathburn, S.L., Whittecar, G.R. (Eds.), Management and Restoration ofFluvialSystemswithBroadHistoricalChangesandHumanImpacts.GeologicalSocietyofAmericaSpecialPaper451,Boulder,CO,USA,pp.83-95.

Wohl,E.,Angermeier,P.L.,Bledsoe,B.,Kondolf,G.M.,McDonnell,L.,Merritt,D.M.,Palmer,M.A., Poff, L., Tarboton, T., 2005. River Restoration,Water Resources Research 41,W10301,doi:10.1029/2005WR003985.

Wyżga, B., Zawiejska, J., Radecki-Pawlik, A., Amirowicx, A., 2010. A method for theassessment of hydromorphological river quality and its application to the Czarny

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Dunajec, Polish Carpathians. In: Radecki-Pawlik, A., Hernik, J. (Eds.), CulturalLandscapes of River Valleys. Agricultural University in Kraków, Kraków, Poland, pp.145-164.

Wyżga,B.,Zawiejska,J.,Radecki-Pawlik,A.,Hajdukiewicz,H.,2012.Environmentalchange,hydromorphological reference conditions and the restoration of Polish Carpathianrivers.EarthSurfaceProcessesandLandforms,DOI:10.1002/esp.3273.

Appendix1.EvaluationFormforConfinedChannels

Morphological Quality Index (MQI)

1 of 5

EVALUATION FORMS FOR CONFINED CHANNELSVersion 2 - October 2016

GENERALITYDate Operators

Catchment Stream/riverUpstream limit Downstream limitSegment code Reach Code Reach length (m)

DELINEATION OF SPATIAL UNITS 1. Physiographic setting

Physiographic context M=Mountains, H=Hills Landscape unit 2. Confinement

Confinement degree (%) >90, 10-90 Confinement index (1-1.5)

3. Channel morphologyAerial photo or satellite image (name, year)

Braiding index 1-1.5, >1.5 Anabranching index 1-1.5, >1.5

River Type (BRT, Basic River Typology) S-T=Single-thread, W= Wandering, B= Braided, A= Anabranching

4. Other elements for reach delineationUpstream Downstreamchange in geomorphic units, bed slope discontinuity, tributary, dam, artificial elements, change in confinement

and/or size of the floodplain, changes in grain size, other (specify)

FURTHER CHARACTERIZATIONDrainage area (at the downstream limit) (km2)

Mean bed slope, S Mean channel width, W (m) Bed sediment (dominant) C=Clay, Si=Silt, Sa=Sand, G=Gravel, C=Cobbles, B=Boulders

Bed configuration BR=bedrock, C=Cascade, SP=Step Pool, PB=Plane bed, RP=Riffle Pool, DR=Dune rippleA= Artificial, NC= not classified (high depth or strong alteration)

River Type (ERT, Extended River Typology) from 0 to 22 (GF= Groundwater-Fed)

Unit stream power (ω=γQS/W) (when available) ≤10, >10 W m-1 Energy setting LE=Low Energy

Additional available data / informationSediment size, D50 (mm) Unit Be=Bed, Ba=Bar (SU=surface layer, SUB=sublayer)

Discharges M=measured, E=estimated, NA=not availableGauging station (if M) Mean annual discharge (m3/s) Q1.5 or Q2 (m3/s)

Maximum discharges (indicate year and Q when known)

GEOMORPHOLOGICAL FUNCTIONALITYContinuity part. prog. conf.F1 Longitudinal continuity in sediment and wood flux

F3

confidence level between A and B conf:confidence level in the answer, with M=Medium, L=Low (High is omitted) confidence level between B and C

ABC

part.: partial score (to circle) prog.: MQI progressive score

Full connectivity between hillslopes and river corridor (>90%)Connectivity for a significant portion of the reach (33÷90%)Connectivity for a small portion of the reach (≤33%)

Hillslope - river corridor connectivity035

Strong alteration (discontinuity of channel forms and interception of sediment and wood) 5

A Absence of alteration in the continuity of sediment and wood 0B Slight alteration (obstacles to the flux but with no interception) 3C

Morphological Quality Index (MQI)

2 of 5

MorphologyMorphological patternF6 Bed configuration - valley slope (applied to Single-thread channels)

Not evaluated for ERT types from 1 to 3, and for deep streams when it is not possible to observe the channel bed

F7 Planform pattern (applied to Multi-thread or Wandering channels)

Cross-section configurationF9

Bed structure and substrateF10

Not evaluated for ERT types from 1 to 3, and for deep streams when it is not possible to observe the channel bed

F11

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

Vegetation in the fluvial corridorF12

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

B

BC

Alteration of bed forms for >66% of the reach

BC1C2

Medium width of functional vegetationLow width of functional vegetation

ABC

ABC

ABC

A

C

A

A

Presence of in-channel large wood

Alterations for a limited portion of the reach (≤33%)Consistent alterations for a significant portion of the reach (>33%)

Absence (≤5%) of alteration of the cross-section natural heterogeneity (channel depth/velocity)Presence of alteration (cross-section homogeneity) for a limited portion of the reach (≤33%)Presence of alteration (cross-section homogeneity) for a significant portion of the reach (>33%)

Variability of the cross-section

Bed forms consistent with the mean valley slope or not consistent for ≤33% of the reachBed forms not consistent with the mean valley slope for 33-66% of the reach

Absence (≤5%) of alteration of the natural heterogeneity of geomorphic units and channel width

Structure of the channel bed

Evident clogging for ≤50% of the reachEvident clogging for >50% of the reach or burial (≤50%)

Significant presence of large wood along the whole reach (or "wood transport" reach)

Negligible presence of large wood for >50% of the reach

High width of functional vegetation

Evident burial (>50%) or alteration by bed revetment (>33% of the reach)

Natural heterogeneity of bed sediments and no significant clogging

Width of functional vegetation

Negligible presence of large wood for ≤50% of the reach

035

035

035

025

0

3

6

2

023

Morphological Quality Index (MQI)

3 of 5

F13 Linear extension of functional vegetation

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

ARTIFICIALITYpart. prog. conf.

A1 Upstream alteration of flows

A1H Upstream alteration of flows without potentially relevant effects on channel morphology

Evaluated for the application of the HMQI

A2 Upstream alteration of sediment discharges

A3

A4 Alteration of sediment discharge in the reach

Where transversal structures, including bed sills and ramps (see A9), are >1 every d1, add 6Where transversal structures, including bed sills and ramps (see A9), are >1 every d2, add 12

where d1=150 m and d2=100 m in steep channels, or d1=750 m and d2=500 m in channels with S≤1%

8

C Reach located between abstraction and restitution section of hydropower plant 16and/or reach immediately downstream of a hydropower reservoir

Linear extension of functional vegetation >90% of maximum available lengthA

4

0B Presence in the catchment of one or more structures altering flow discharges

6

Significant alteration (>10%) of channel-forming discharges

Bor release of increased low flows downstream dams during dry seasons

B

Steep channels (S>1%): consolidation check dams >1 every 200 m and/or retention check damsor presence of a dam or artificial reservoir at the downstream boundary (any bed slope)

C

C2C1

BC

A

Upstream alteration of longitudinal continuity

Absence or negligible presence of structures for the interception of sediment fluxesA

(dams for drainage area ≤5% and/or check dams/abstraction weirs for drainage area ≤33%)

A Absence of any type of structure altering flow discharges (dams or other abstractions)

Dam at the upstream boundary of the reach

B1

C

A

No significant alteration (≤10%) of channel-forming discharges and with return interval>10 yearsB

Dams (area 5-33%) and/or check dams/weirs with total bedload interception (area 33-66%)

Dams (drainage area 33-66%) and/or check dams/weirs with total bedload interception

A

C

036

Significant alteration (>10%) of discharges with return interval>10 years

0

3

12

and/or check dams/weirs with partial interception (area >66%)

9Dams for drainage area >66%

0

Linear extension of functional vegetation 33÷90% of maximum available lengthLinear extension of functional vegetation ≤33% of maximum available length

No significant alteration (≤10%) of channel-forming discharges and with return interval>10 yearsSignificant alteration (>10%) of discharges with return interval>10 years 3

6

Alteration of flows in the reach

0

Significant alteration (>10%) of channel-forming discharges

Absence of structures for the interception of sediment fluxes (dams, check dams, abstraction weirs)Channels with S≤1%: consolidation check dams and/or abstraction weirs ≤1 every 1000 mSteep channels (S>1%): consolidation check dams ≤1 every 200 m and/or open check damsChannels with S≤1%: consolidation check dams and/or abstraction weirs >1 every 1000 m

035

Alteration of longitudinal continuity in the reach

B2 6

Morphological Quality Index (MQI)

4 of 5

A5 Crossing structures

Alteration of lateral continuityA6 Bank protections

For a high density of bank protection (>50%) add 6For an extremely high density of bank protection (>80%) add 12

Alteration of channel morphology and/or substrateA9 Other bed stabilization structures

d=200 m in steep channels (S>1%); d= 1000 m in channels with S≤1%For a high density of bed revetment (impermeable >50% or permeable >80%) add 6

For an extremely high density of bed revetment (impermeable >50% or permeable >66%) add 12

Intervention of maintenance and removalA10 Sediment removal

Not evaluated in the case of ERT type 1

A11 Wood removal

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

A12 Vegetation management

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

BC

AB

C1C2

ABC

ABC

Presence of protections for ≤33% total length of the banks (sum of both banks)Presence of protections for >33% total length of the banks (sum of both banks)

Absence of structures (bed sills/ramps) and revetmentsSills or ramps (≤1 every d) and/or revetments ≤25% permeable and/or ≤15% impermeable

Absence of crossing structures (bridges, fords, culverts)

Partial removal of woody material during the last 20 yearsTotal removal of woody material during the last 20 years

of aquatic vegetation, or no cutting of riparian but partial or total cutting of aquatic vegetation

Sills or ramps (>1 every d) and/or revetments ≤50% permeable and/or ≤33% impermeableRevetments >50% permeable and/or >33% impermeable

Absence of significant sediment removal activities during the last 20 yearsLocalized sediment removal activities during the last 20 yearsWidespread sediment removal activities during the last 20 years

Absence of removal of woody material at least during the last 20 years

B Selective cuts and/or clear cuts of riparian vegetation ≤50% of the reach and partial or no cutting

A

3

0

Presence of many crossing structure (>1 every 1000 m in average in the reach)

Absence or localized presence of bank protections (≤5% total length of the banks)

BC

A

6

0368

03

2

5

6

02

3

02Presence of some crossing structure (≤1 every 1000 m in average in the reach)

C Clear cuts of riparian vegetation >50% of the reach, or selective cuts and/or clear cuts of riparian 5vegetation ≤50% of the reach but total cutting of aquatic vegetation

A No cutting interventions on riparian vegetation (last 20 years) and aquatic vegetation (last 5 years) 0

Morphological Quality Index (MQI)

5 of 5

CA1 Adjustments in channel pattern

Not evaluated in the case of small streams where resolution of aerial photos is insufficient

CA2 Adjustments in channel width

Not evaluated in the case of small streams where resolution of aerial photos is insufficient

CA3 Bed-level adjustments

Not evaluated in the case of absolute lack of data, information and field evidences

Total deviation (MQI): Stot =

Maximum deviation: Smax = 119 - Sna= where Sna = sum of maximum scores for those indicators that have not been applied

Morphological Alteration Index: MAI = Stot / Smax = if Stot>Smax it is assumed MAI=1

Morphological Quality Index: MQI=1-MAI =

Morphological Quality class of the reach

0≤MQI<0.3: Very Poor or Bad; 0.3≤MQI<0.5: Poor; 0.5≤MQI<0.7: Moderate; 0.7≤MQI<0.85: Good; 0.85≤MQI≤1.0: Very Good or High

Total deviation (HMQI): Stot + S(A1H) =

Hydro-Morphological Quality Index: HMQI=1-Stot+S(A1H) / Smax =

Hydro-Morphological Quality class of the reach

0≤HMQI<0.3: Very Poor or Bad; 0.3≤HMQI<0.5: Poor; 0.5≤HMQI<0.7: Moderate; 0.7≤HMQI<0.85: Good; 0.85≤HMQI≤1.0: Very Good or High

A

B

B

ABC

A

Changes in channel width >15% since 1930s - 1960s

Negligible bed-level changes (≤0.5 m)Limited to moderate bed-level changes (0.5÷3 m)Intense bed-level changes (>3 m)

Change of channel pattern since 1930s - 1960s

Absent or limited changes in channel width (≤15%) since 1930s - 1960s

Absence of change of channel pattern since 1930s - 1960s

CHANNEL ADJUSTMENTS

0

part.

48

3

03

0

prog. conf.

Appendix 2. Evaluation Form for Partly Confined or UnconfinedChannels

Morphological Quality Index (MQI)

1 of 5

EVALUATION FORMS FOR PARTLY CONFINED AND UNCONFINED CHANNELSVersion 2 - October 2016

GENERALITYDate Operators

Catchment Stream/riverUpstream limit Downstream limitSegment code Reach Code Reach length (m)

DELINEATION OF SPATIAL UNITS 1. Physiographic setting

Physiographic context M=Mountains, H=Hills, P=Plain Landscape unit 2. Confinement

Confinement degree (%) >90, 10-90, ≤10Confinement index 1-1.5, 1.5-n, >n (n=5 single-thread or anabranching; n=2 braided or wandering)Confinement class PC=Partly confined, U=Unconfined

3. Channel morphologyAerial photo or satellite image (name, year)

Sinuosity index 1-1.05, 1.05-1.5, >1.5Braiding index 1-1.5, >1.5 Anabranching index 1-1.5, >1.5

River Type (BRT, Basic River Typology) ST=Straight, S=Sinuous, M=Meandering,W= Wandering, B= Braided, A= Anabranching

4. Other elements for reach delineationUpstream Downstreamchange in geomorphic units, bed slope discontinuity, tributary, dam, artificial elements, change in confinement

and/or size of the floodplain, changes in grain size, other (specify)

FURTHER CHARACTERIZATIONDrainage area (at the downstream limit) (km2)

Mean bed slope, S Mean channel width, W (m) Bed sediment (dominant) C=Clay, Si=Silt, Sa=Sand, G=Gravel, C=Cobbles, B=Boulders

Bed configuration BR=bedrock, C=Cascade, SP=Step Pool, PB=Plane bed, RP=Riffle Pool, DR=Dune rippleA= Artificial, NC= not classified (high depth or strong alteration)

River Type (ERT, Extended River Typology) from 0 to 22 (GF= Groundwater-Fed)Unit stream power (ω=γQS/W) (when available) ≤10, >10 W m-1 Energy setting LE=Low Energy

Additional available data / informationSediment size, D50 (mm) Unit Be=Bed, Ba=Bar (SU=surface layer, SUB=sublayer)

Discharges M=measured, E=estimated, NA=not availableGauging station (if M) Mean annual discharge (m3/s) Q1.5 or Q2 (m3/s)

Maximum discharges (indicate year and Q when known)

GEOMORPHOLOGICAL FUNCTIONALITYContinuity part. prog. conf.F1 Longitudinal continuity in sediment and wood flux

F2 Presence of a modern floodplain

Not evaluated in the case of mountain streams along steep (>3%) alluvial fans

confidence level between A and B conf:confidence level in the answer, with M=Medium, L=Low (High is omitted) confidence level between B and C part.: partial score (to circle)

Presence of a discontinuous (10÷66%) but wide floodplain or >66% but narrowB2 Presence of a discontinuous (10÷66%) and narrow floodplain

Absence of a floodplain or negligible presence (≤10% of any width)

prog.: MQI progressive score

Strong alteration (discontinuity of channel forms and interception of sediment and wood)

Presence of a continuous (>66% of the reach) and wide floodplainB1

C

A Absence of alteration in the continuity of sediment and woodBC

A

Slight alteration (obstacles to the flux but with no interception) 35

02

5

0

3

Morphological Quality Index (MQI)

2 of 5

F4

Not evaluated in the case of Low Energy ERT types from 17 to 22 and Groundwater-Fed streams

F5

MorphologyMorphological patternF7 Planform pattern

F8 Presence of typical fluvial landforms in the floodplain

Cross-section configurationF9

Bed structure and substrateF10

Not evaluated for deep rivers when it is not possible to observe the channel bed

F11

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

Vegetation in the fluvial corridorF12

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

BC

C1C2

0

A

C

AWidth of functional vegetation

Significant presence of large wood along the whole reach (or "wood transport" reach)

Negligible presence of large wood for >50% of the reach

High width of functional vegetation

BC

A

Natural heterogeneity of bed sediments and no significant armouring, clogging or burialEvident armouring or clogging for ≤50% of the reachEvident armouring or clogging (>50%), or burial (≤50%), or occasional substrate outcrops

3

AB

APresence of a potentially erodible corridor

Complete absence (≤2%) or widespread presence (>50%) of eroding banks by mass failures

Presence of a wide potentially erodible corridor (EC) for a length >66% of the reach

Negligible presence of large wood for ≤50% of the reachB

BC

A

C

B

Bank erosion occurs for >10% and is distributed along >33% of the reachProcesses of bank retreat

A

Variability of the cross-section

Presence of alteration (cross-section homogeneity) for a limited portion of the reach (≤33%)Presence of alteration (cross-section homogeneity) for a significant portion of the reach (>33%) 5

Absence (≤5%) of alteration of the cross-section natural heterogeneity (channel depth)

Evident burial (>50%), or substrate outcrops or alteration by bed revetments (>33% of the reach)

Absence (<5%) of alteration of the natural heterogeneity of geomorphic units and channel widthAlterations for a limited portion of the reach (≤33%)Consistent alterations for a significant portion of the reach (>33%)

Structure of the channel bed

Presence of a potentially EC of any width for 33-66% of the reach or for >66% but narrowPresence of a potentially EC of any width for ≤33% of the reach

0

3

0

Bank erosion occurs for ≤10%, or for >10% but is concentrated along ≤33% of the reach

23

035

0

023

56

3

02

2

3

or significant presence (>25%) of eroding banks by mass failures 2

BC

A

0

Presence of floodplain landforms (oxbow lakes, secondary channels, etc.)Presence of traces of landforms (abandoned during the last decades) but with possible reactivationComplete absence of floodplain landforms

2

BC

Presence of in-channel large wood

Medium width of functional vegetationLow width of functional vegetation

Morphological Quality Index (MQI)

3 of 5

F13 Linear extension of functional vegetation

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

ARTIFICIALITYpart. prog. conf.

A1M Upstream alteration of flows with potentially relevant effects on channel morphology

A1H Upstream alteration of flows without potentially relevant effects on channel morphology

Evaluated for the application of the HMQI

A2 Upstream alteration of sediment discharges

A3 Alteration of flows in the reach

A4 Alteration of sediment discharge in the reach

Where transversal structures, including bed sills and ramps (see A9), are >1 every d1, add 6Where transversal structures, including bed sills and ramps (see A9), are >1 every d2, add 12

where d1=150 m and d2=100 m in steep channels, or d1=750 m and d2=500 m in channels with S≤1%

B2

C2

B

C

C1

Alteration of longitudinal continuity in the reach

Dams (drainage area 33-66%) and/or check dams/weirs with total bedload interception(drainage area >66% or at the upstream boundary)

ABC

A

C

A

B1Dams (area 5-33%) and/or check dams/weirs with total bedload interception (area 33-66%)and/or check dams/weirs with partial interception (area >66%)

Significant alteration (>10%) of channel-forming dischargesor release of increased low flows downstream dams during dry seasons

No significant alteration (≤10%) of channel-forming discharges and with return interval>10 yearsSignificant alteration (>10%) of discharges with return interval>10 yearsSignificant alteration (>10%) of channel-forming discharges

5

03

0Significant alteration (>10%) of discharges with return interval>10 years

Dam at the upstream boundary of the reach

Absence or negligible presence of structures for the interception of sediment fluxes

Steep channels (S>1%): consolidation check dams >1 every 200 m and/or retention check damsor presence of a dam or artificial reservoir at the downstream boundary (any bed slope)

Absence of structures for the interception of sediment fluxes (dams, check dams, abstraction weirs)

3

6

12

BC

A

BChannels with S≤1%: consolidation check dams and/or abstraction weirs ≤1 every 1000 m

6

0

Dams for drainage area >66%

36

9

0

Steep channels (S>1%): consolidation check dams ≤1 every 200 m and/or open check damsChannels with S≤1%: consolidation check dams and/or abstraction weirs >1 every 1000 m

No significant alteration (≤10%) of channel-forming discharges and with return interval>10 years

6

3

Upstream alteration of longitudinal continuity

(dams for drainage area ≤5% and/or check dams/abstraction weirs for drainage area ≤33%)A

Linear extension of functional vegetation >90% of maximum available lengthLinear extension of functional vegetation 33÷90% of maximum available lengthLinear extension of functional vegetation ≤33% of maximum available length

11

0

4

C Reach located between abstraction and restitution section of hydropower plant 22and/or reach immediately downstream of a hydropower reservoir

A Absence of any type of structure altering flow discharges (dams or other abstractions) 0B Presence in the catchment of one or more structures altering flow discharges

Morphological Quality Index (MQI)

4 of 5

A5 Crossing structures

Alteration of lateral continuityA6 Bank protections

For a high density of bank protection (>50%) add 6For an extremely high density of bank protection (>80%) add 12

A7 Artificial levees

For a high density of bank-edge levees (>66%) add 6For an extremely high density of bank-edge levees (>80%) add 12

Alteration of channel morphology and/or substrateA8 Artificial changes of river course

In case of historical drainage and dredged works for >50% of the reach, add 6In case of historical drainage and dredged works for >80% of the reach, add 12

(when an additional score for A6 and/or A7 is not already applied)

A9 Other bed stabilization structures

d=200 m in steep channels (S>1%); d= 1000 m in channels with S≤1%

For a high density of bed revetment (impermeable >50% or permeable >80%) add 6For an extremely high density of bed revetment (impermeable >80%) add 12

Intervention of maintenance and removalA10 Sediment removal

A11 Wood removal

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

C

A

C

BC

A

A

C

A

C

AB

A

C1

B

C2

BC

AB

B

Presence of some crossing structures (≤1 every 1000 m in average in the reach)Presence of many crossing structures (>1 every 1000 m in average in the reach)

Absence of crossing structures (bridges, fords, culverts)

Absence of artificial changes of river course in the past (meanders cut-off, channel diversions, etc.)Presence of changes of river course for ≤10% of the reach lengthPresence of changes of river course for >10% of the reach length

Absence of structures (bed sills/ramps) and revetmentsSills or ramps (≤1 every d) and/or revetments ≤25% permeable and/or ≤15% impermeableSills or ramps (>1 every d) and/or revetments ≤50% permeable and/or ≤33% impermeable

Absence of removal of woody material at least during the last 20 yearsPartial removal of woody material during the last 20 yearsTotal removal of woody material during the last 20 years

Revetments >50% permeable and/or >33% impermeable

Absence of recent (last 20 years) and past (last 100 years) significant sediment removal activities

Sediment removal activity either in the past (last 100 years) and during last 20 years

036

0

0

36

02

Absence or localized presence of bank protections (≤5% total length of the banks)Presence of protections for ≤33% total length of the banks (sum of both banks)Presence of protections for >33% total length of the banks (sum of both banks)

Absent or set-back levees, or presence of close and/or bank-edge levees ≤5% bank lengthBank-edge levees ≤50%, or ≤33% in case of total of close and/or bank edge>90%Bank-edge levees >50%, or >33% in case of total of close and/or bank edge>90%

3

0

5

368

0

6

23

02

Recent sediment removal activity (last 20 years) but absent in the past (last 100 years)Sediment removal activity in the past (last 100 years) but absent during last 20 years B1

B234

Page61of177

Morphological Quality Index (MQI)

5 of 5

A12 Vegetation management

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

CA1 Adjustments in channel pattern

Not evaluated in the case of small streams where resolution of aerial photos is insufficient

CA2 Adjustments in channel width

Not evaluated in the case of small streams where resolution of aerial photos is insufficient

CA3 Bed-level adjustments

Not evaluated in the case of absolute lack of data, information and field evidences

Total deviation (MQI): Stot =

Maximum deviation: Smax = 142 - Sna= where Sna = sum of maximum scores for those indicators that have not been applied

Morphological Alteration Index: MAI = Stot / Smax = if Stot>Smax it is assumed MAI=1

Morphological Quality Index: MQI=1-MAI =

Morphological Quality class of the reach

0≤MQI<0.3: Very Poor or Bad; 0.3≤MQI<0.5: Poor; 0.5≤MQI<0.7: Moderate; 0.7≤MQI<0.85: Good; 0.85≤MQI≤1.0: Very Good or High

Total deviation (HMQI): Stot + S(A1H) =

Hydro-Morphological Quality Index: HMQI=1-Stot+S(A1H) / Smax =

Hydro-Morphological Quality class of the reach

0≤HMQI<0.3: Very Poor or Bad; 0.3≤HMQI<0.5: Poor; 0.5≤HMQI<0.7: Moderate; 0.7≤HMQI<0.85: Good; 0.85≤HMQI≤1.0: Very Good or High

B

C

Selective cuts and/or clear cuts of riparian vegetation ≤50% of the reach and partial or no cutting 2

5Clear cuts of riparian vegetation >50% of the reach, or selective cuts and/or clear cuts of riparianvegetation ≤50% of the reach but total cutting of aquatic vegetation

A

A

C

036

BAbsence of changes of channel pattern since 1930s - 1960sChange to a similar channel pattern since 1930s - 1960sChange to a different channel pattern since 1930s - 1960s

0ABC

Absent or limited changes (≤15%) since 1930s - 1960sModerate changes (15÷35%) since 1930s - 1960sIntense changes (>35%) since 1930s - 1960s

36

No cutting interventions on riparian vegetation (last 20 years) and aquatic vegetation (last 5 years)

of aquatic vegetation, or no cutting of riparian but partial or total cutting of aquatic vegetation

Limited to moderate bed-level changes (0.5÷3 m)

0

4812

AB

C1C2

Intense bed-level changes (>3 m)Very intense bed-level changes (>6 m)

Negligible bed-level changes (≤0.5 m) 0

CHANNEL ADJUSTMENTS conf.prog.part.

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Appendix3.GuidetotheCompilationoftheEvaluationForms

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A3.1 IntroductionThisGuideprovidesdetailedinstructionsandsupportforthecompilationoftheMQIevaluationforms.Foreachindicator,anextendedversionofthepossibleanswersisreported,including:Spatialscale(longitudinalandlateral);Typeofmeasurements(e.g.fieldsurvey,remotesensing,orothersourcesofinformation);

• Confinementtype(confined,partlyconfinedorunconfined);• Rangeofapplication(forthoseindicatorsthatarenotappliedinspecificcases).

Concerningthelongitudinalspatialscale,thefollowinggeneralindicationsareprovided.In the case of indicators assessed by remote sensing, the longitudinal spatial scalecorresponds to the entire reach. In the case of indicators which need field surveyobservation/measurement, the assessment is focussed on the ‘site’ scale (i.e., one orpreferablymore sub-reaches selected as themost representative of the reach), althoughadditionalchecksalongothersitesshouldbeconsidered(e.g.forindicatorswhichneedthedefinitionofthelateralextentand/orcontinuityalongthereach).Finally,artificialelementsmustberecognisedandassessedalongthewholereach.

A3.2 GeneralityanddelineationofspatialunitsThefirstpartoftheevaluationformisdedicatedtosomegeneralinformation,includingthedateofthefieldsurvey(althoughthecompletecompilationoftheevaluationformrequiresapreparationphaseandaconclusionphaseofthemeasurementsafterthefieldvisit),andthename(s)oftheoperators.Thenthenameofthecatchmentandofthestream/riverisindicated.Theupstreamanddownstreamlimitsofthereachmustbeclearlydefined(e.g.nameofatributary,ifthisrepresentsalimit,orplanimetriccoordinates)andtheidentificationcodeofthesegmentandreach,andthereachlengthneedtoberecorded.Inthethecaseofanabranchingchannels,thereachlengthiscalculatedastheaverageofthesinglechannels.Inthoseindicatorswhichrefertothepercentageofreachlength,thisisintendedasthepercentageofthetotallength(i.e.sumofallindividualchannels).

Thefollowingpartoftheformisdedicatedtoall informationandmeasurementsmadeduring the four steps of the general setting and initial segmentation. During step 1, thephysiographicsetting(physiographiccontextandlandscapeunit)isspecified.Duringstep2,thedetailsfortheclassificationofconfinementareprovided.Notethat,asforalltheindicesreported in this section, the operator can report the precise value of the index, or onlyspecify the class (e.g. > 90%, 10÷90% or ≤ 10% for the confinement degree). Step 3 isdedicatedtochannelmorphology.Firstofall,thenameoftheimage(aerialphotographorsatellite image) used as a reference for all observations aimed at morphologicalclassificationisindicated.Then,theindicesusefultodefinethechannelpattern(sinuosity,braiding,andanabranchingindices)arereported,andtheresultingBasicRiverType(BRT)isdefined.Instep4,informationregardingotherelementsforreachdelineationisreported.

Therefollowsasectionconcerningthefurthercharacterization,basedontheadditionalinformationcollected(mostlyinthefield)atthestartoftheMQIassessment.Thefirstsetofinformationconcernsthefollowingfeatures:(i)drainagearea;(ii)dominantbedsediment;(iii) mean bed slope; (iv) mean channel width; (v) bed configuration. In the case ofanabranchingrivers, themeanbedslope iscalculatedastheaverageof thebedslopesofthesinglethreads,whereasthechannelwidthiscalculatedasthesumofthewidthsofall

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threads. Based on the dominant bed sediment, the Extended River Type (ERT) and theenergy setting (low-energy streamreach)aredefined. Finally, additionaldata/informationconcerningsedimentsizeanddischarge,canbealsoincluded,whenavailable.

A3.3 GeomorphologicalFunctionalityContinuity

A3.3.1 F1:Longitudinalcontinuityinsedimentandwoodflux

DESCRIPTION

This indicator evaluates whether the longitudinal continuity of sediment and woodmaterial is altered by human structures that intercept or create obstacles to their flow(discontinuitiesdue tonatural factors, suchas rockoutcroppings, lakesor landslidedamsarenotconsidered).

SpatialscaleLongitudinal:Site/Reach Lateral:ChannelMeasurements:Remotesensingandfieldsurvey

Theassessmentdoesnotdependonthenumberofalterations,butontheirrelevance:justonestructurecancauseacompletealterationoftheflux,whereasmanystructuresmayhaveno significanteffects (thenumberof structures is accounted for in the indicatorsofArtificiality). The main artificial structures are dams, check dams, and weirs. Otheralterationscanbeduetocrossingstructures(bridges,fords)oralsogroynes.Inthecaseofastructure located at the upstream reach limit, this is conventionally assigned to theupstream reach (see indicators of Artificiality), but the effects on the longitudinalcontinuityareconsideredforthedownstreamreach(Figure1).Therefore,theeffectofastructure locatedat thedownstreamlimit isnotevaluatedfor thatreach,but for theonedownstream.

FigureA3.1Longitudinalcontinuityinsedimentandwoodflux.Ruleofassignationofatransversalstructure locatedatthelimitbetweentworeaches,anditseffectsonlongitudinalcontinuity.

The assessment is first based on remote sensing, noting whether existing structurescreateacleardifferentiationinthepresenceandextensionofdepositionalformsupstreamand downstream from the structure. Field checks are then required to better assess theimpactofexistingstructures(e.g.toverifywhetherthestructurecausesaselectivefluxofsedimentandwood).

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EXTENDEDANSWERS

Confinement type All typologies

A

Absence or very negligible presence of alterations in the continuity of sediment and wood flux, that is, there are no significant obstacles or interceptions to the free passage of solid material related to transversal and/or crossing structures (e.g. bridge with no piers or wide span, check dams or weirs completely filled and significant changes in depositional features and sediment size upstream and downstream the structure). In the case of presence of anabranches: absence or very negligible presence of alteration in all the anabranches, or slight alteration in a secondary anabranch.

B

Slight alteration in the continuity of sediment and wood flux, that is, most solid material is able to flow along the reach. Depositional forms may exist, indicating sedimentation of the coarsest fractions of bedload by crossing structures and/or groynes, but with no complete interception (e.g. bridges with narrow spans and piers, series of consolidation check dams in mountain areas, or check dams filled with coarse sediments but with significant difference in grain size from upstream to downstream); larger sizes of wood is held by bridge piers and/or open check dams. In the case of presence of anabranches: slight alteration in the main anabranch or in more anabranches (class B for the main anabranch or more anabranches), or strong alteration in a secondary anabranch or in more anabranches but absence of alteration in the remaining anabranches (i.e. combination of classes A and C).

C

Strong alteration in the continuity of sediment and wood flux, that is, a strong discontinuity of depositional forms (sediments) exist in upstream and downstream structures because bedload is strongly intercepted (e.g. not filled weirs or check dams or, in mountain systems, check dams filled by fine sediments). In the case of presence of anabranches: strong alteration in all the existing anabranches or strong alteration in the main anabranch or in more anabranches and slight alteration in the remaining anabranches (i.e. combination of classes B and C).

ILLUSTRATEDGUIDE

Confinedchannels

Class A Class B

FigureA3.2Longitudinalcontinuityinsedimentandwoodflux.ClassA:absenceofdiscontinuities.ClassB:upontheright,filledconsolidationcheckdams;lowontheleft,opencheckdam.ClassC:acheckdam(arrow)withtotalinterceptionrepresentsacompletealterationoflongitudinalcontinuityinthereachdownstreamfromthecheckdam.

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Class B Class C

FigureA3.2(continued)Longitudinalcontinuityinsedimentandwoodflux.ClassA:absenceofdiscontinuities.ClassB:upontheright,filledconsolidationcheckdams;lowontheleft,opencheckdam.ClassC:acheckdam(arrow)withtotalinterceptionrepresentsacompletealterationoflongitudinalcontinuityinthereachdownstreamfromthecheckdam.

Partlyconfinedandunconfinedchannels

Class A Class B

Class C

FigureA3.3Longitudinalcontinuityinsedimentandwoodflux.ClassA:absenceofdiscontinuities.ClassB: filledcheckdam(arrow)alteringthenormalfluxofsedimentbutwithoutcausingtotal interceptionandadiscontinuityof forms(barsareobservedeitherupstreamanddownstream).ClassC:presence of a weir or check dam with total sediment interception resulting in a significant alteration of the reachimmediatelydownstream(theriverflowsfromrighttoleft).

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A3.3.2 F2:Presenceofamodernfloodplain

DESCRIPTION

Ariverindynamicequilibriumbuildsamodernfloodplainthatisgenerallyinundatedfordischargesjustexceedingchannel-formingflows(returnintervalof1÷3years).Thepresenceof amodern, frequently inundated floodplain promotes several importantmorphological,hydrological and ecological functions (attenuation of flood peak discharges, energydissipation, fine sediment deposition, groundwater recharge, flood pulse, turnover ofriparian habitats, etc.). Bed incision or artificial structures (levées) can alter thischaracteristicformanddisconnectthefloodplainfromchannelprocesses.

Lateralextensionandlongitudinalcontinuityofamodernfloodplainisconsideredhereasanindicatorofexistinglateralcontinuityofwaterandsedimentfluxes.

Spatial scale Longitudinal: Site/Reach Lateral: Entire floodplain (including recent terraces) Measurements: Remote sensing and field survey

Thefloodplainisatypicalgeomorphicfeatureofpartlyconfinedandunconfinedchannels,therefore the indicator is not applied to confined channels (even though, in some cases,smallfloodplainareascanalsoberecognizedalongconfinedchannels).Theindicatorisnotappliedinmountainareasalongsteepalluvialfans(>3%),wherethefloodplainisdifficulttoidentifyeveninnaturalconditions.

Theabsence(orlimitedpresence)ofamodernfloodplainisatypicalconditionofincisedrivers,thereforethisindicatorwillneedparticularcareforsuchcases.Inthecaseofriversthatarenotincised,themodernfloodplaincoincideswiththeoverallfloodplain;howeverinsuchcasesthissurfacemaybedisconnectedfromthechannelbecauseofthepresenceofartificiallevées,sotheirpresenceanddistancefromthechannelneedtobeassessed.

GEOMORPHOLOGICALDEFINITIONOFMODERNFLOODPLAIN

Amodernfloodplain(oractiveorgeneticfloodplain)isanalluvial,flatsurfaceadjacenttotheriver,createdby lateralandverticalaccretionduringthepresentregimeconditions.Ariver in dynamic equilibrium builds a modern floodplain that is generally inundated fordischargesjustexceedingchannel-formingflows(returnintervalof1÷3years).

Itisimportanttonotethatthe‘modern’floodplainevaluatedbythisindicatordoesnotcorrespondtotheentirefloodplain,whichisconsideredwhenevaluatingtheconfinement,but in general is only a portion of that wider surface. This is clear in recently incisedchannels(i.e.last100÷150years,asisverycommoninmostEuropeancountries),wherethemodern floodplaincorresponds to recent surfaces formedafter the lastphaseof incision.Themodernfloodplainisthereforedistinguishedfrom‘recent’terraces(whichcorrespondwithabandonedorinactivefloodplains),i.e.thosesurfacesaffectedbyfloodingofalargerreturninterval(generally>3years),andwhichwereoftenthemodernfloodplainbeforetheincision. Accordingly, in the case of recent incision (the last 100÷150 years) the entirefloodplainmayincludethemodernfloodplainandrecentterraces.

However, in those caseswhere incision has been small (to the order of about 1m orless), the portions of abandoned channel remain hydrologically identifiedwith amodern

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floodplain. In such cases, considering thepractical difficulty of discriminating them in thefield,thesesurfacesareevaluatedasamodernfloodplaininF2.

Thefieldidentificationofamodernfloodplainisbasedonarangeoffieldevidence:(1)morphological and topographical continuity amongst channel depositional features (i.e.bars); (2) presence of fine sediment; (3) relatively dense vegetation cover, with strongpresenceofmaturevegetation (i.e. trees); (4)evidenceof flooding (e.g.woodydebris). Insomecasesfieldevidenceispoororunrecognizable(e.g.farmingfields,vegetatedterraces).

Note that, according to the definition of confinement (see section 1.3.2), in NorthernEurope it is possible that some floodplains are composed of fluvio-glacial or fluvio-lacustrinedeposits,characterisedbyalargesedimentsizevariabilityrangingfromveryfine(lacustrinedeposits)tocoarse(glacialorfluvio-glacialdeposits).Inthesecases,themodernfloodplain is still defined as a surface that is frequently inundated (return interval of 1÷3years).

METHODSFORFLOODPLAINDELINEATIONANDFORMEASURINGCONTINUITYANDLATERALEXTENT

The identification and delineation of the modern floodplain is carried out by remotesensing and field survey. In some cases, additional methods can be used, including: (a)photo interpretation and/or DEMs, provided they are at a resolution sufficient foridentifying differences in elevation between alluvial surfaces; (b) hydraulicmodelling: theresults ofmodelling normally used for the delimitation of flooding areas can support thedelineationofthefloodplain(i.e.forfloodsoflowreturnperiod).

The evaluation of this indicator is based on the assessment of themodern floodplaincontinuity,definedasthepercentageofreachlengthwithpresenceofmodernfloodplain,evenifonlyononesideofthechannel,andlateralextent,i.e.itsoverallwidth(sumofbothsides). Islands are included in the calculation of both modern floodplain continuity andlateralextent,exceptinthecaseofterracedislands(i.e.islandshigherthanthelevelofthemodernfloodplain).Foranabranchingchannels,thecontinuityisassessedforall individualthreads,andiscalculatedasapercentageofthesumofthelengthofallthreads).ClassAisassociatedwithalateralextentatleastequaltonW,whereWisthechannelwidth,n=2forsingle-threadoranabranchingchannels,andn=1forbraidedorwanderingchannels.Thelowervalueofnforbraidedandwanderingchannelsisexplainedbythenarrowerchannelareainvolvedinlateralmobilityandtherelativelyhigherchannelwidthcomparedtosingle-thread channels. In the case of partly-confined channels, where the modern floodplainoccupiesalloftheavailablevalleyfloor,thereachis inclassAevenifthelateralextent islowerthannW.

Measuresoflateralextentfromremotesensing(GIS)canbecarriedoutintwoways:(1)intermsofanaveragealongthereachofvaluesmeasuredonrepresentativetransects;(2)by calculating the ratio “floodplain area/channel area”. In some particular cases (i.e.problemsinthedelimitationofthemodernfloodplainareafromremotesensing)themeanmodernfloodplainwidthcanbemeasuredinthefieldinrepresentativesections.

INTERACTIONWITHOTHERINDICATORS

F2interactswithseveralothersindicators,mainlythefollowing:(1) Vegetation in the fluvial corridor (F12 and F13): in some cases, the vegetated fluvialcorridor adjacent to the river channel corresponds to or includes themodern floodplain.Indeed, the vegetated surfaces are often at a lower level compared to agricultural lands,

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whereasinothercasesthesevegetatedareascorrespondtoterraces.Forthesereasons,theidentificationofthemodernfloodplainanditsdistinctionfromthevegetatedfluvialcorridorshouldbecarriedoutinthefield.Agriculturallandsgenerallyoccupyterraces,exceptinthecasewherethereisnobedincision.(2)Thepresenceofartificiallevées(A7)automaticallypreventsthesurfacesexternaltothelevées frombeingmodern floodplain,while thesurface includedbetweenset-back levéesandthebankedgescanpotentiallybeamodernfloodplainoraterrace.(3) Adjustments in channelwidth (CA2): previous portions of channel bed abandoned bynarrowing,associatedwith limitedormoderatebed incision,are likely tocorrespondtoamodernfloodplain.(4)Verticaladjustments(CA3): incisioncausesthehydrologicaldisconnectionbetweentheriverchannelanditsfloodplain.However,anewfloodplainsurfacemaydevelopafterbedincision, and so vegetated surfacesadjacent to the streamcouldbeamodern floodplain.However,ifnoincisionhasoccurred,themodernfloodplainoftencorrespondstotheentirefloodplain(evenifitiscompletelyoccupiedbyagriculture).

FLOW-CHARTTOGUIDETHEDEFINITIONOFTHECLASS

Figure4showsadiagramtosupport the identificationof themodern floodplaintakinginto account the interaction of F2 with the other related indicators (mainly CA3). Thediagram assumes that artificial levées are absent or, if present, the modern floodplaincannot extend behind them. The proposed scheme is not exhaustive, given that otherparticularcasescouldoccurthatarenotincludedhere.

FigureA3.4SketchoftheinteractionsbetweenF2andotherrelatedindicators.ClassBmaycorrespondtoB1orB2,dependingonthewidthofthemodernfloodplain.

Incision

Incised Low incision and narrowing Not incised

F2 in A* Vegetated fluvial corridor

Negligible presence

(≤10% reach)

F2 in C

F2 in C or B

Good continuity and wide* (F12 in A

and F13 in A or B)

Field check

F2 in C, B o A*

Field check

(CA3 in class B or C) (CA3 in class A) (limited incision and CA2 in class B or C)

Field check and GIS (change between

1930s-1960s and present)

F2 in B or A* Medium or low

lateral extent (F12 in B or C)

(*) except in the case of bank edge and/or close artificial levees

(*) becomes C or B in the case of bank edge and/or close

artificial levees

(*) becomes C or B in the case of bank edge and/or close

artificial levees

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EXTENDEDANSWERS

Confinement type Partly confined or unconfined

Range of application

Not evaluated in the case of mountain streams along steep (>3%) alluvial fans

A

Presence of a relatively continuous (> 66% of the reach length) and sufficiently wide modern floodplain, that is, when the mean width (sum on the two sides) is at least twice the channel width (W) in the case of single-thread or anabranching channels (types 10, 12-14, 16-22), or at least 1 W in the case of braided or wandering channels (types 8, 9, 11, 15). For anabranching channels, the reach length is the sum of the lengths of the individual anabranches.

B1

Presence of a discontinuous modern floodplain (10÷66% of the reach length) but sufficiently wide, that is, when the mean width (sum on the two sides) is at least twice the channel width (W) in the case of single-thread or anabranching channels (types 10, 12-14, 16-22), or at least 1 W in the case of braided or wandering channels (types 8, 9, 11, 15). Or presence of a continuous (> 66% of the reach length) but not sufficiently wide modern floodplain, that is, when the mean width (sum on the two sides) is ≤ 2 W in the case of single-thread or anabranching channels, or ≤ 1 W in the case of braided or wandering channels (types 8, 9, 11, 15).

B2

Presence of a discontinuous modern floodplain (10÷66% of the reach length) not sufficiently wide, that is, when the mean width (sum on the two sides) is ≤ 2 W in the case of single-thread or anabranching channels (types 10, 12-14, 16-22), or ≤ 1 W in the case of braided or wandering channels (types 8, 9, 11, 15).

C Absence of a modern floodplain or negligible presence (≤ 10% of the reach length of any width).

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ILLUSTRATEDGUIDE

1

2

3

4

FigureA3.5Differencesbetweenamodernfloodplainandarecentterrace.(1)and(2)Examplesofmodernfloodplain(notetheverylimiteddifferencesinelevationwithchannelbars);3:recentterracegeneratedbyabedincisionofabout2÷3m;4:recentterracegeneratedbyanintenseincision(>3m).

ClassA

FigureA3.6Case1.Thechannel isnot incised (V3 inClassA), therefore theadjacentalluvial surfacecorresponds toamodern floodplain(ClassA).

Modern floodplain

Modern floodplain

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ClassB

FigureA3.7Case2.Thechannelisslightlyincisedandnarrowedcomparedto1930s-60s.Vegetationinthefluvialcorridorisquitewide(F12in Class B) and mostly coincides with the channel of 1930s-60s. The field assessment enables verification that thevegetation corridor coincideswith themodern floodplain, resulting therefore inClassB (B1 orB2, dependingon thefloodplainwidth).

ClassB

FigureA3.8Case3.Thechannelismoderatelyincisedandslightlynarrowedcomparedto1930s-60s.Vegetationcorridoriscontinuousandwide(F12andF13inClassA).Fieldassessmentenablesverificationthatthevegetationcorridoralsoincludesportionsofrecentterraces,thereforethefloodplainisnotsufficientlywide(ClassB1orB2).

ClassB

FigureA3.9Case4.The channel is incised and the vegetation corridor has a medium width (F12 in Class B). Field assessment enablesverification that most of the vegetations corridor corresponds to a modern floodplain formed after incision asconsequenceoflateralmobility(ClassB1orB2).

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ClassC

FigureA3.10Case5.Thechannelisheavilyincised(>6m)andnarrowed,andthevegetationcorridorhasamediumwidth(F12 inClassB).Field assessment enables verification that the vegetation in this case occupies portions of the 1930s-60s channeldisconnectedbythepresentchannel(recentterraces)(ClassC).

ClassC

FigureA3.11Case6.Thechannelisheavilyincised(>6m)andvegetationcorridorthatcouldbeapost-incisionfloodplainisabsent(F12 inClassC),thereforethereachisnecessarilyinClassC.

A3.3.3 F3:Hillslope–rivercorridorconnectivity

DESCRIPTION

The linkage between hillslopes and river corridor is evaluated here in the case ofconfined channels, as this is very important for thenatural supplyof sediment and largewood.The indicator refers to theoverall river corridor (including small anddiscontinuousportionsofmodernfloodplainand/orrecentterraceswhichmaybepresentalongconfinedstreams),given thata largequantityofhillslopematerial can temporarilybestoredalongsmall portions of modern floodplains or terraces before being involved in sedimenttransport.Ontheotherhand,theindicatordoesnotevaluatethepresenceofapotentiallyerodiblecorridor.

The connectivity between hillslopes and river corridor is based on the presence andpercentageonthereachlength(i.e.sumofbothsides)ofelementsofdisconnectionsuchasroads,aswellasstructuresforlandslidesprotection,inastripconventionally50mwideforeachsideoftherivercorridor (i.e.,channelandfloodplain),startingfromthebaseofthehillslopes. Agricultural terraces are also considered as elements of disconnection as theyreducethepotentialsupplyofsediment.

Thestripcaneasilybeobtainedfromremotesensing,oncetherivercorridorisdefined,but a field survey to check the presence of intercepting structures is also recommended(e.g. in forested river corridors). The width of 50 m, for simplicity, is evaluated as the

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horizontal projection. Possible sub-horizontal surfaces located on the top of the hillslope(e.g., inthecaseofaterrace)but includedwithinthestripof50mareexcludedfromtheanalysis,astheydonotpotentiallycontributetothesedimentandwoodsupply.

Spatial scale Longitudinal: Reach Lateral: Floodplain/adjacent hillslopes Measurements: Remote sensing and field survey

EXTENDEDANSWERS

Confinement type Confined

A A full connectivity exists between hillslopes and river corridor (channel and floodplain), extending for most of the reach (> 90%).

B The connectivity between hillslopes and river corridor exists for a significant portion of the reach (33÷90%).

C The connectivity between hillslopes and river corridor exists for a small portion of the reach (≤ 33%).

ILLUSTRATEDGUIDE

ClassACONNECTIVITY>90%

ClassBCONNECTIVITY33÷90%

ClassCCONNECTIVITY≤33%

ROADSOROTHERDISCONNECTINGSTRUCTURES

LIMITSOF50MSTRIP

FigureA3.12Connectivitybetweenhillslopesandfluvialcorridor.Classesasafunctionofthelinkbetweenstreamandadjacenthillslopesforastrip50mwideonbothsidesstartingfromthebaseofthehillslopes.

A3.3.4 F4:Processesofbankretreat

DESCRIPTION

Bank erosion is a key process contributing to sediment supply as well as to thedevelopment of the floodplain and the turnover of riparian vegetation and habitats. It isnecessarytoevaluatewhetherbankerosionprocessesoccurasexpectedforagivenriver

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type (e.g.erosionalongtheoutermeanderbend inmeanderingchannels),or if there isasignificant difference, such as absence of erosion due to widespread bank control, orexcessivebankfailuresduetoinstabilityofthesystem(e.g.duetochannelincision).

Spatial scale Longitudinal: Site/Reach Lateral: Channel Measurements: Remote sensing and field survey

This indicator isappliedonlytopartlyconfinedandunconfinedchannels,giventhat inconfined channels the banks are often directly in contact with the slopes, and hillslopeprocessesdominate(seeindicatorF3).

Moreover, the indicator is not applied in Low-Energy streams. In such rivers, bankerosioncanstilloccur,butusuallyatsignificantlylowerratescomparedtootherrivertypes.Therefore,itwouldbeextremelydifficulttodefinetheminimumlevelofbankerosionthatisexpectedinunalteredconditionsforsuchrivers.

Whereasbankerosioniscommonlyexpectedinmeanderingrivers,thisisnotthecaseofLow-Energy streams having ‘passivemeandering’. They are quite common in some northEuropean regions (e.g.,many regionsofUK,etc.), andare characterisedbyameanderingpattern (e.g., type 21) that changes very slowly or is inherited from past geologicalconditionsandatpresentnolongerhasthestreampowernecessarytodeformthechannelboundariesthroughactivebedscourandbankerosion(underfitstreams).

Forallotherrivertypes(mediumtohighenergyrivers)theindicatorevaluateswhetherbankerosionprocessesarealteredalong the reach. Twoopposite situationsof alterationareconsidered:(1)bankerosionprocessesarelackingortheyclearlyoccurlessfrequentlythan expected; (2) bank erosion processes are clearly in excess of what would beexperiencedinunalteredconditions.Thetwosituationsareinvestigatedasfollows.(1)Bankerosionprocessesoccur less frequently thanexpected.Thescarceoccurrenceofbankerosionmaynotonlyberelatedtobankprotections,butalsotoother interventionsthatmay induceasignificantreduction inbedslopeandtherefore instreamenergy(e.g.,upstream of dams, weirs, check dams, etc.). Three classes are defined: (A) frequentretreating banks; (B) retreating banks less frequent than expected, i.e. bank erosion isobservedlocallyandforlimitedlengths;(C)completeabsenceornegligiblepresence(verylocalized erosion) of retreating banks. The definition of precise values of expected bankerosioninnaturalconditionsisextremelyproblematic.However,indicativeminimumlevelsofexpectedbankerosionareprovidedtodefinethethresholdsofthedifferentclasses(seeextendedanswers)inordertoreducesubjectivityinthechoice.Furthermore,inunalteredconditions (classA) a sufficiently homogeneous distribution of retreating banks along thereach is expected, i.e. the minimum level of expected bank erosion should not beconcentratedonlyinasmallportionofthereach(seeextendedanswers).(2)Anexcessiveamountofbankerosionoccursalongthereach.Inthiscase,theindicatorintendstoaccountforthosesituationsofwidespreadbankfailuresrelatedtobed incisionor to strong alterations of the flow regime: for example, hydropeaking may cause rapidwater leveloscillations inducinganexcessive levelofmass failuresalongthereach. Inthefirst case, two diagnostic elements can be used to assess this condition: (1) in mostretreating banks, mass failures are the dominant processes responsible for bank retreat(e.g., rotational, planar, cantilever failures, etc.); (2) this strong alteration is normally

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associated with intense bed-level changes (i.e. the indicator CA3 is in class C) and bankfailuresoccurringalongscarpsdelimitinglowterracesgeneratedbythisincision.Inthecaseof hydropeaking, the excessive erosionmay not necessarily occur in reaches affected byintenseincision,butthissituationisrecognisedwhentheoccurrenceofhydropeakingalongthe reach isevident,andbank retreatmainlyoccursdue tomass failures,becauseof therapiddrawdownduringtherecessionalphaseofthehydrograph.

The length of eroding banks along the reach is evaluated from remote sensing, whilefieldsurveyisusefulforinterpretingthetypesofbankerosionprocesses,i.e.massfailuresinthecaseofexcessiveerosionbyincisionorhydropeaking,orforverifyingsituationswhicharenotsufficientlyclearfromremotesensing.Therefore,thefrequencyofbankerosionsisreferred to the date of the remote sensing image used for the overall application of theindex,anddoesnotrequireupdating in the field incaseofsomenewbankerosionbeingnoted. Sub-reaches where the channel is directly in contact with hillslopes or ancientterracesareexcludedfromtheassessment.

EXTENDEDANSWERS

Confinement type Partly confined or unconfined Range of application

Not evaluated in the case of Low-Energy ERT types from 17 to 22, including Groudwater-Fed streams

A

Bank erosion occurs for a sufficient length (a minimum of >10% of the total length of the banks, excluding portions directly in contact with hillslopes or ancient terraces), and with a sufficiently homogeneous distribution (i.e. bank erosions are distributed along >33% of the reach length), as expected for the river typology. For instance, erosion frequently occurs in the outer bank of bends (types 12, 13, 14) and/or in front of bars (types from 8 to 11 and 15).

B

Moderate alteration of bank erosion processes: bank erosion occurs less frequently than expected for the river typology (≤10% of the total length of the banks), because impeded by protective elements and/or scarce channel dynamics related to other human interventions (e.g., reduction in bed slope related to check dams or weirs). Or bank erosion occurring for >10% but concentrated on a limited portion of the reach (≤33% of reach length). Or significant presence (>25% of the total length of the banks) of unstable, eroding banks by mass failure related to excessive bank height because of bed incision or to alterations of flow regime (hydropeaking).

C

Complete absence (very localized erosion, i.e. ≤2% of the total length of the banks) of retreating riverbanks due to excessive human control (bank protection, reduction in bed slope related to check dams or weirs) (except for Low-Energy reaches: see range of application). Or significant presence (>50% of the total length of the banks) of unstable, eroding banks by mass failure related to excessive bank height because of bed incision or to alterations of flow regime (hydropeaking).

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassC

FigureA3.13Processesofbankretreat.Class A: frequent retreating banks (red arrows, photo on the left), as expected for the river typology.Class B: bankerosion occurs less frequently than expected for the river typology.Class C, 1,2: complete absence or very localizedpresenceoferodingbanksduetoexcessivehumancontrol.3,4significantpresenceofunstable,erodingbanksbymassfailurerelatedtoanexcessivebankheightbecauseofbedincision.

1 2

3 4

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A3.3.5 F5:Presenceofapotentiallyerodiblecorridor

DESCRIPTION

The presence of a potentially erodible corridor is nowadays widely recognised as apositive attribute of rivers. This indicator evaluates the potential for the river to movelaterallyoverthenextdecades(asopposedtotheindicatorF4whichevaluatesthecurrentprocesses of bank erosion). As for F4, this is applied to partly confined and unconfinedrivers. The indicator is also applied to Low-Energy streams, even though the rate andextension of bank erosion may be low. The presence of fixing structures or artificialelements that protect against possible erosion may alter the expected natural lateralmobilityofallrivertypes.

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) Measurements: Remote sensing

A rapid assessment is performed by evaluating whether the width and longitudinalcontinuityofareaswithoutrelevanthumanstructuresorinfrastructures(e.g.houses,roads)arewithinoroutofgivenranges.Artificialstructureswhichlimitthewidthoftheerodiblecorridorare:bankprotectionstructures,embankments,artificiallevées,aswellasallotheranthropic elements (e.g. houses, main roads) which would be protected from lateralchannel dynamics. Past bank protection structures (e.g. groynes), even if no longer incontactwith the channel, are considered as structureswhich can potentially prevent thelateralchanneldynamics(whiletheyarenottakenintoaccountintheindicatorA6).Otherminorstructures,suchasfarmedfieldsanddirtpatchesorroads,arenottakenintoaccountbythisindicator.

The width of the potentially erodible corridor is defined and measured as for theindicatorF2. For classA, thewidthof thepotentially erodible corridor (the sum for bothsidesoftheriver,althoughanerodiblecorridormayonlybepresentononeside)mustbeatleastequal tonW,whereW is thechannelwidth,n=2 forsinglethreadoranabranchingchannels,andn=1forbraidedorwanderingchannels.

The continuity is measured (similarly to the indicator F2) as the percentage of reachlengthwiththepresenceofapotentiallyerodiblecorridor,evenwhenonlyononeside.Inthe case of meandering channels (types 14, 18, 21), the continuity of the potentiallyerodible corridor is calculated exclusively as a % of the length of the external meanderbanks,i.e.innermeanderbanksarenotevaluated.

Inthecaseofanabranchingchannels,thecontinuityofthepotentiallyerodiblecorridoriscalculatedas%ofthesumofthelengthsofalltheanabranches,andthewidthincludesislands(iferodible).Inthecaseofpartlyconfinedchannels,wherethepotentiallyerodiblecorridorcorrespondstoalltheavailablefloodplain,thereachisattributedclassAevenifthewidthoftheerodiblecorridorislowerthannW.

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EXTENDEDANSWERS

Confinement type Partly confined or unconfined

A

Presence of a relatively continuous (> 66% of the reach length) and sufficiently wide potentially erodible corridor (EC), that is, the mean width (sum of the two sides) is at least twice the channel width (W) in the case of single-thread or anabranching channels (types 10, 12-14, 16-22), or at least 1 W for braided or wandering channels (types 8, 9, 11, 15). In the case of presence of anabranches, the reach length is intended as the sum of the lengths of all anabranches.

B Presence of a potentially erodible corridor (EC) with medium continuity (33÷66% of the reach length) and any width; or a potentially EC for > 66% of the reach length but not sufficiently wide.

C Presence of a potentially erodible corridor (EC) of any width but with low continuity (≤ 33% of the reach length).

ILLUSTRATEDGUIDE

ClassA>66%ANDWIDE(>nW)

ClassB33÷66%

ClassB>66%BUTNARROW

(≤nW)

ClassC≤33%

URBANAREAS LEVEESAND/ORBANKPROTECTIONS

INFRASTRUCTURES LIMITSOFTHEPOTENTIALLYERODIBLECORRIDOR

FigureA3.14Potentiallyerodiblecorridor.ClassA:notwithstandingtheconstructedareaandtheroad,acontinuousandsufficientlywideerodiblecorridorexists.ClassB:theerodiblecorridorhasamediumlongitudinalcontinuity(33÷66%)(secondfigurefromleft),oritiscontinuous(>66%)butnotsufficientlywide(meanwidth≤nW)(thirdfigurefromleft).ClassC:apotentiallyerodiblecorridor(ofanywidth)existsonlyfor≤33%ofthereach.

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Morphology

A3.3.6 F6:Bedconfiguration–valleyslope

DESCRIPTION

Geomorphicunitscharacterizing thechannelconfigurationrepresent themain focusofthe first two indicators ofmorphology. They are applied either to confined single-threadchannels (F6)or tounconfined–partlyconfinedandconfinedtransitionalormulti-threadchannels(F7)respectively.

Inthecaseofconfinedsingle-threadchannels,theplanimetricpatternisimposedbythehillslopesandtherefore isnotsignificant intermsofmorphologicalassessment,whilebedconfiguration (i.e., the instream geomorphic units characterizing the channel bed) is adiagnosticelementof themorphological functionality.This indicatorevaluateswhetherornot the presence of transversal structures has altered the expected bed configuration(cascade,step-pool,planebed,riffle-pool,dune-ripple)basedonthemeanbedslopeofthereach.Infact,astrongcorrelationexistsbetweenbedslopeandconfiguration,suchthatforincreasing slopes the following order of forms is expected with increasing slope: dune-ripples (only in sand-bed channels), riffle-pool, plane bed, step-pool / cascade. Thesemorphologieshaveecological implicationsaseachofthemischaracterizedbyamosaicoftypicalphysicalhabitats.

The existence of a transversal structure can cause an artificial lowering of the localenergyslopeandthereforeapossiblealterationofthebedconfigurationand,consequently,of the associated physical habitats. This indicator intends therefore to evaluate themagnitudeofchangecausedbytransversalstructuresandnotjusttheirpresence(whichisevaluatedintheindicatorsofartificiality).

Spatial Scale Longitudinal: Site/Reach Lateral: Channel Measurements: Field survey and Remote sensing

This indicator isevaluatedonly in thecaseofalluvialsingle threadconfinedchannels,i.e. ERT types from 4 to 7 (in the case of multi-thread or wandering channels, it issubstitutedbyF7,thereforeF6andF7arenecessarilymutuallyexclusive).

The operator should determine the mean valley slope along the reach (based on thelongitudinalbedprofilealreadyusedduringthesegmentationphase),andthendefinetheexpectedbedformaccordingtoTable1.Class limitsmayhavesomeoverlap,dueto localreach conditions, which can modify (expand/reduce) the boundaries between bedconfiguration morphologies. Typical alterations of bed configuration are associated withhydraulicstructuresonhighgradientchannels(i.e.checkdamsonstep-poolmorphology),whichaimtolimitriverenergyandpreventbedloadtransport.However,theamountofbedconfigurationalterationdependsontheinitialreachconditions,thelocalbedloaddynamicsand the geometry of the structures (width, number and distance between structures): insome cases, for example, check dams do not modify the bed configuration morphology(fromonetypetoanother)butonlythesizeofmorphologicalunits(e.g.steps,pools,etc.).Inlowgradientchannels(i.e.lessthanapproximately0.2%),bedconfigurationdependsonthebedsedimentsize(gravelorsand)andbanksedimenttype(cohesiveornon-cohesive).Thisallowsdune-ripplechannels(i.e.sandsubstrateanddeeper)tobedistinguishedfrom

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riffle-pool channels (i.e. gravel substrate and shallower), where single-thread dune-rippleperennialchannelscannotdevelopatahigherbedslope(>0.2%).Riffle-poolandplane-bedmorphologiesmayalsohavesomeoverlapintermsofbedslope(between1and2%)aswellasplane-bedandstep-poolmorphologies(between3and4%).Thisvariabilitydependsonthe localbedloadconditions (amountand transportcapacity)and the lateral confinementimposedbyhillslopes.

Themean valley slope along the reach is simply calculated as the ratio between theoveralldifferenceinelevationandthereachlength(Figure15).Inthecaseoflongreachesinwhichthebedslope ishighlyvariable, it issuggestedtocalculatethebedslope insub-reaches(eventuallydelimitedbycrossingstructures).Shouldthereachlimitcorrespondtoacrossingstructure(damorweir),bedelevationimmediatelydownstreamfromthestructure(correspondingtotheoriginalbedelevation) isconsideredforthecalculationofthemeanslope. In the case of an artificial reservoir being located at the downstream limit of thereach, the lowerbedelevationused for valley slope calculation should correspond to thestartingpointofthereservoir.TableA3.1Relationsbetweenrangeofbedslopeandexpectedbedforms.

Theassessment is carriedout in the field (ifpossibleby remotesensing)by identifyingtheprevailingbedconfigurationmorphologyandcheckingitsconsistencywiththeexpectedmorphology based on Table 1. When artificial transversal structures are present, bedconfiguration is evaluated between the structures. In the absence of such structures,possible differences between the expected and the observedmorphology can be due tolocalnaturalfactors(e.g.logsteps,landsides,moraines,etc.)butthesearenotconsideredas alterations. Even in the case of transversal structures, natural factors can cause somelocal difference between expected and observed morphology. For this reason, thethresholdsbetweenclassAandBandbetweenclassBandC(33%and66%,respectively)arehigherthanthoseusedforotherindicatorsoffunctionality.

Bed forms Dominant grain size Range of bed slope (%) Dune-ripple Sand and fine gravel ≤ 0.2 Riffle-pool Gravel and cobbles ≤ 2 Plane bed Cobbles and gravel 1÷4 Step-pool/cascade Boulders and cobbles > 3

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EXTENDEDANSWERS

Confinement type Confined

Range of application

Applied to alluvial single-thread channels (ERT types from 4 to 7). Not evaluated in the case of confined with bedrock or colluvial channels (ERT types from 1 to 3), and in the case of deep streams when it is not possible to observe the bed configuration

A

Bed forms consistent with the mean valley slope: bed configuration corresponds to that expected, based on the mean valley slope along the reach (Table 1), or bed forms not consistent for a length ≤ 33% of the reach. Included in this class are also the morphologies imposed by natural factors (e.g. log steps, landslides, etc.) which locally can determine unexpected bed forms (e.g. riffles in a steep reach, step-pool in a low gradient reach).

B

Bed forms not consistent with the mean valley slope for a length > 33% and ≤ 66% of the reach, because bed configuration does not correspond to that expected, based on the mean valley slope along the reach (Table 1), because of presence of transversal structures (dams, check dams, weirs, sills, ramps, etc.).

C

Bed forms not consistent with the mean valley slope for a length > 66% of the reach, because bed configuration does not correspond to that expected, based on the mean valley slope along the reach (Table 1), because of presence of transversal structures (dams, check dams, weirs, sills, ramps, etc.).

ILLUSTRATEDGUIDE

FigureA3.15Bedconfigurationandvalleyslope.Ruleforthemeasurementofthemeanvalleyslopeofthe reach in the presence of structures (check dams)and to identify the length of analysis of bedmorphology.

ClassA ClassB ClassC

FigureA3.16Bedconfigurationandvalleyslope.ClassA:consolidationcheckdamsthatdonotaltertheexpectedbedconfigurationbasedonvalleyslope(steppoolinboth cases). Class B: some consolidation check dams determine a bed configuration (plane bed) different from theexpected one (cascade / step pool) for a length <66% of the reach Class C: extended (>66% of the reach length)alterationofbedconfiguration,duetoclosely-spacedtransversalstructures.

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A3.3.7 F7:Planformpattern

DESCRIPTION

This indicator concerns the features characterizing the planform pattern of alluvialchannels,includingthegeomorphicunitsandthelongitudinalvariabilityinchannelwidth(whereasthemorphologicalcharacteristics incross-sectionareseparatelyassessedbyF9).Theaimistoevaluatewhetherthesefeaturesarethoseexpectedforthechannelpattern(e.g., braiding, meandering, etc.), or there are alterations in their presence and spatialdistribution.Thepresenceofinstreamgeomorphicunits,aswellasthevariabilityofchannelwidth,haveimportantimplicationsintermsofecologicalconditions,astheydeterminetheavailability and variability of physical habitats. Past changes in channel planform patternrelated to human interventions (e.g., meander cutoff) or channel adjustments are notconsideredbythis indicator,astheyareevaluatedseparately inother indicators(A8,CA1,andCA2).

Differently from F6, this indicator assesses geomorphic units which characterize theplanformpattern,whereasnoconsiderationismadeinthiscaseonthebedconfiguration.Thegeomorphicunitsarethosetypicalofalluvialchannels,suchasbars, islands,benches,as well as secondary channels or anabranches which characterize multi-threadmorphologicalpatterns(e.g.braided,anabranching).Alteredsituationscanberelatedtothepresence of artificial elements, including interventions/actions which modify the normalpattern of geomorphic units (e.g. transversal structures, channel resectioning, instreamsedimentorvegetationremoval,etc.)orcanbeassociatedwithchanneladjustments(e.g.incised reacheswith the disappearance of geomorphic units). An increase of geomorphicunits related to some artificial element can also be an alteration. For example, theoccurrenceofbarsandbraidingcausedbyalocalalterationofsedimentflow(e.g.upstreamand/or downstream froma bridgeor another transversal structure) along a single-threadchannelisevaluatedasanalteration.

Longitudinalvariability inchannelwidthalongthereachisconsideredasanadditionalfeature of the overall planimetric characteristics. For example, braided channels arenormally characterized by a succession of nodes-islands, as well asmeandering channelswithpointbarswhichnormallyhavesomevariabilityinchannelwidth,whilealackofwidthheterogeneitymaybecausedbyartificiallyfixedbanks.

Spatial scale Longitudinal: Reach Lateral: Channel Measurements: Field survey and/or remote sensing

The indicator is applied to partly confined and unconfined channels, as well as towandering or multi-thread confined channels (for single-thread confined channels, theindicatorF6isapplied).Theindicatorismainlyevaluatedbyremotesensingintegratedwithfieldsurveyatrepresentativesites.

Fortheapplicationofthisindicator,itisnecessarytocontextualizetheassessmenttothetypeofchannelpatterncharacterizingthereach.Threemainsituationscanbeconsideredintermsofmorphological typologies: (1)single-threadchannels (types12-14,16-18,20and21), (2)wanderingorbraidedchannels(types8,9,11,15),and(3)anabranchingchannels(types10,19,22).

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(1)Single-threadchannels.Artificialchannelfixationand/orexcessivechannelmaintenance(e.g.barclearing)arethemostfrequenthumaninterventionsalteringtheplanformpatternin single-thread channels (i.e. a lack of typical geomorphic units and of longitudinalvariabilityinchannelwidth).InthecaseofLow-Energysinglethreadchannelswithnaturalabsenceofunvegetatedbars(e.g.types20and21oftheERT),vegetatedbarsandbenchesaretypicalgeomorphicfeaturespromotingchannelwidthvariability.(2)Wanderingandbraidedchannels.Classificationofthereachasoneoftheserivertypesduring the segmentation phase implies that characteristic geomorphic features (mid-channelbars,bifurcations,etc.)arenecessarilypresentalongthereach,butcan locallybemodifiedbythepresenceofartificialstructures(e.g. local lossofbraidingpatternbecauseoftransversalstructures).(3)Anabranching channels. Anabranching channels are characterised by the presence ofvariousanabranchesseparatedbyvegetatedislands.Eachanabranchcanexhibitaspecificmorphology attributable to theother channel typesdescribedabove. In the caseof Low-Energy anabranching channels (i.e. anastomosing), the single anabranch channels can bedescribedasstraighttomeanderingsingle-thread.Inthecaseofhighenergyanabranching,single anabranchesmay include bars and exhibit awandering or even a braided channelmorphology.Therefore,foranabranchingchannelstheassessmentofchannelmorphologycanbereferredtootherchanneltypes.

A particular case for the application of this indicator is when some river restorationinterventionhasrecentlybeencarriedoutalongthereach.Theremovalofconstrains(e.g.,fixed banks)may induce a natural occurrence of geomorphic units (andwidth variability)which can be considered as a morphological change towards a more natural planformpattern: therefore, in such cases, the indicator changes frommorealtered to lessalteredconditions. More problematic is the case of morphological restoration (i.e. artificialmodification inchannelpattern), forexamplewhenacompletelynewplanformpattern isimposed(e.g.,fromabraidedtoameandering).Ingeneral,theindicatorF7shouldnotbeapplied for theyears immediately after the intervention since the riverneedsa sufficienttimetoadapttothenewlyimposed(restored)conditions.Afewyears(i.e.atleast5years)are required following the restoration intervention for correctly interpreting the newcondition.

LONGITUDINALEXTENTOFTHEALTERATION

In termsof the longitudinaldistributionandextentof thealterationalong thereach,acommon case iswhen aportionof the reach exhibits the natural pattern of geomorphicunits characterizing a given morphology, but in other portions of the same reach thismorphological planform pattern is altered. In this case the evaluation is straightforwardbecause the unaltered portions of the reach are actually considered as the referencepattern of geomorphic units andwidth variability characterizing the reachmorphologicaltype (forexample,a reachclassifiedasbraidedmayhavesomeportionwhere the typicalcharacteristicsofthebraidedpatternarenotpresent).

Amoreproblematiccasecanbewhentheentirereach(orevenmoreadjacentreachesoranentiresegment)isaltered.Thiscaseisnotalwaysstraightforwardandrequiressomecaution in the interpretation onwhether or not the observed channel pattern is the oneexpectedinthecontextofitssegmentandlandscapeunitsetting.

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It is important to stress that reference conditions forMQIarenotdefined in termsofaprecisechannelconfiguration (e.g.,meandering,braided)orawell-definedsetofchannelcharacteristics. This is because rivers are dynamic and follow complex evolutionarytrajectories through time in response to variations of a series of driving variables andboundary conditions, so it is not possible to define such a precisemorphology in a staticway.Expressingthisinanotherway,reasoningsuchas‘inthisreachtheriverismeanderingbutshouldbebraided’isdeliberatelyavoided.However,itisgenerallypossibletoidentifyarange of morphologies and typical geomorphic units (rather than a precise channelpattern) that would be normally expected in a given context and position within thecatchment(e.g.inamountainarea,highplain,orlowland),andthereforetorecognisewithagooddegreeofconfidencewhenanobservedmorphologyisclearlybeyondthephysicalcontextofthereachlocation.

Thefollowingtwocasesindicatewhentheentirereachshouldbeevaluatedasaltered.

1.Highlyimpactedreachwithanartificial(orartificiallyfixed)planform.Thisisthecaseofan artificially imposed morphology (e.g., predominantly artificial bed and/or heavilyengineered, stabilisedbanks).Straight (orvery lowsinuous)alluvial,unconfined (orpartlyconfined) reaches are in most cases an artificial planform, given that natural straightchannels generally occur for short distances. When the planform is artificially fixed bycontinuousbankprotections,thealterationoftheplanformisobvious.Eveninthecaseofsinuousormeanderingreacheswithcompletelyfixedbanks,theabsenceofwidthvariabilitycan be considered as a sufficient condition to evaluate the reach as altered. Moreproblematic can be the case of typical single-thread, straight sinuous Low-Energymorphologies, i.e.ERT types17or20, showingwidthhomogeneity,occasionalornobars,andbanksthatarenotartificiallyfixed.Insuchacase,thequestioniswhetheritisornotanaturalplanform,andcautionshouldbeusedintheevaluation(seecriterialater).

2.Highlyimpactedreachinducedbyabruptchanneladjustments.Lessobviouscanbethecase of a reach that is not artificially fixed, but has been affected by dramatic channeladjustments, e.g., bed incision and narrowing altering itsmorphology and bed substrate,andcreatingamorphologicalconfigurationthatisclearlybeyondthephysicalcontextwherethe reach is located. An examplemight be a single-thread channelwith occasional or nobars,thatisatypicalmorphologyassociatedtoaLow-Energysetting(e.g.ERTtypes17,18,20or21),locatedinacontextofmediumtohighenergy(alluvialfan,highormediumplain)whereamorphologywithahigherabundanceofbarsisexpected.Thismorphologycanberelatedforexampletoanintensebedincisionandeventuallybed-rockoutcroppingthatcanbe clearly associated to some human causes (e.g., sediment deficit created by dams orcheckdamsupstream,sedimentmining,etc.).Somecautionsshouldbemadeinthistypeofevaluation (see criteria later). In particular, only the caseswhena channelmorphology iscompletelyoutof the context shouldbeassessedasanalteration, suchasa typical Low-Energy configuration in amedium-highenergy setting.A channelmorphology that can fitwithin the range of possible morphologies in a given context (e.g., a free sinuous ormeandering gravel-bed river with bars in a medium-high energy setting) will not beconsideredasanalteration.

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CriteriafortheassessmentThe following criteria can be used to assess a reach-scale alteration because the rivermorphologyisbeyondthephysicalcontextforthelocationofthereach.(1)Physicalsettingwherethereachisplaced.Thisincludesconsiderationsonthepositionin thecatchment,especially in termsof landscapeunitwhere thesegment is located, theupstream landscapeunitsand theirgeneral characteristics in termsofvalleygradientandpotential bedload supply. Table 2 provides a summary of the most typical channelmorphologiesthatcouldbeexpectedinaseriesofphysicalsettings.Notethatthetableisnotprescriptivebutprovidesonlysomegeneral indications:iftheobservedmorphologyisoutoftherangeofthetypicalexpectedmorphologies,moreinvestigationisneededTableA3.2Channelmorphologiesgenerallyexpectedforsomemainphysicalsettings.

Physicalsetting TypicalrangeofchannelmorphologyIntermontaneplainsinmountainareaswithhighsedimentsupply

Braided, wandering or high-energyanabranching (ERT types from 8 to 11) mosttypicalSingle-thread, coarse-grained channels (ERTtypes from 12 to 14) also possible in partlyconfinedsettings

Plains in low-gradient formerly-glaciatedvalleysofmountainareas

Sinuous or meandering, relatively fine-grained(13,14,17,18,20,21)arepossible

Alluvial fans or high (piedmont) plains withupstreamareasofhighsedimentsupply

Typically braided, wandering, high-energyanabranching(ERTtypesfrom8to11,15)ERT types from12 to 14 also possible in partlyconfinedsettings

Hilly areaswithprevailinghard rocks, relativelyhigh valley gradient and medium to highsedimentsupply

Braided, wandering, high-energy anabranching(ERTtypesfrom8to11,15)arepossible,orERTtypesfrom12to14

Hilly areas with prevailing soft rocks, relativelylow valley gradient and relatively low coarsesedimentsupply

Prevailingsingle-threadchannels (ERTtypes12-14,16-18)

Lowland and coastal plains with low valleygradient

ERTtypesfrom17to22

(2) Spatial distribution of channel morphology. The most reliable and diagnosticinformationistolookatthechannelmorphologyoftheadjacentupstreamanddownstreamreaches, or the typical morphology of unaltered streams in the same area and physicalsetting.Afavourablecaseiswhen,upstreamanddownstreamfromtheinvestigatedreach,the planform pattern is characterized by clearly distinct geomorphic units and/or widthvariability,andaclearhumanfactorforsuchadifferentpatternalongthereachinquestionis identified (Figure 17). For example, a single-thread reach (characterized by fixed banksandheavymaintenanceactivity)betweenupstreamanddownstreambraidedreachescanbe considered as entirely altered (Figure 17). An opposite case might be a braided (orwandering)confinedchannelclearlyrelatedtothepresenceofseveralcheckdamsbetweenupstream and downstream single-thread, confined reaches (e.g., ERT types 4, 5, 6 or 7).Other causesofalterationof thepatternofgeomorphicunits canbe indirectly related tohumanactivities.Forexample,adeeplyincisedreach(whereincisionisrelatedtosedimentremovalorstronginterceptionofbedloadupstream)withalossofthealluvialsubstrateand

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associatedgeomorphicunits, inacontextwhereanalluvialchannelwithabundantbars isexpected,canbeconsideredasanalteration.InaLow-Energysetting,acompletelystraight,artificial reach within a more natural (sinuous, meandering or anabranching) pattern isobviouslyanalteredplanformconfiguration(Figure17B).

1 2

FigureA3.17Examplesofalteredreaches.1: River segmentwithin a high, intermontane plain in amedium-high energy settingwith high lateral and upstreamsediment supply. Reach 2 is in class C as it shows a typical Low-Energy morphology (single-thread with no bars)associatedtoincisionandnarrowingcausedbyacheckdamandsedimentremoval,whereasreaches1and3exhibitabraided andwanderingmorphology, respectively, with abundance of bars. 2: River segment in a typical Low-Energysetting(lowlandplain).Reaches1and3aresinuous(locallyanabranching)whereasreach3exhibitsaclearlyartificialplanformpattern(classC)duetopaststraighteningandheavilyengineered,stabilisedbanks.

Finally, it is important to remark that temporal changes in channel morphology areaddressedbytheChannelAdjustment indicators,andthereforethepastplanformpattern(1930s – 1960s: see CA1) is not used here as a criterion. However, the interpretation ofalterations of channel pattern should be consistent with channel adjustments indicators(e.g.,interpretationofadeeplyincisedreachwithacompletelyalteredmorphologymustbeconsistentwithCAindicators).

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EXTENDEDANSWERS

Confinement type All typologies

Range of appl ication

In the case of confined channels it is applied only to multi-thread or wandering morphologies (ERT types 8-11, 15, 19, 22). It is not applied in the case of recent (last 5 years) interventions of morphological restoration.

A

Absence or negligible presence (≤ 5% of the reach length) of alteration of the natural heterogeneity of geomorphic units and channel width expected for that river type. Braided (types 8, 9, 15): typical presence of a multi-thread configuration with several bifurcations and longitudinal bars, frequent pioneer islands and some mature islands, longitudinal variability of channel width with node-island alternation. Anabranching (types 10, 19, 22): typical presence of a multi-thread pattern with variable degree of sinuosity and anabranch channels separated by vegetated islands. Wandering (type 11): typical alternate side bars, chute cut-offs, low-water channel highly sinuous and relatively narrow within the bankfull channel, localized braiding phenomena, presence of pioneer islands and in some cases mature islands, longitudinal variability of channel width. Sinuous or meandering with bars (types 13-14, 17-18): side or point bars, possible chute cut-offs, longitudinal variability of channel width in relation to the presence of bars and curvatures. Sinuous pseudo-meandering (types 12, 16): typical alternate side bars, chute cut-offs, low-water channel highly sinuous and relatively narrow within the bankfull channel, longitudinal variability of channel width but less evident than in wandering – braided channels. Low-energy single-thread (types 20, 21): longitudinal variability of channel width in relation to the presence of benches, curvature, and some occasional bank erosion. In some cases (e.g. reaches close to the river mouth), they do not necessarily exhibit a significant heterogeneity of geomorphic units and variability of channel width even in natural conditions.

B Alteration for a limited portion of the reach (≤ 33% of the reach length) of the natural heterogeneity of geomorphic units and channel width expected for that river type.

C Significant alteration for a significant portion of the reach (> 33% of the reach length) of the natural heterogeneity of geomorphic units and channel width expected for that river type.

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassC

FigureA3.18.Planformpattern:examplesformulti-thread,transitional,andsingle-threadchannels.Class A: absence of alterations. Class B: a bridge can alter the morphological pattern (≤ 33% of the reach) by theformation of islands. Class C: in case of a braided or transitional channel, a bridge and a check dam can producesignificantalterationsinthereach(>33%).Inthecaseofasingle-threadchannel,bankprotectionscausealossofthegeomorphicunitsandofthelongitudinalvariabilityinchannelwidth,althoughtheameanderingplanimetricpatternispreserved.

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A3.3.8 F8:Presenceoftypicalfluvialformsinthefloodplain

DESCRIPTION

This indicator accounts for the presence or absence of typical fluvial forms (such asoxbowlakes,secondarychannels,ridgesandswalesmoreor lesshydrologicallyconnectedto the channel, etc.) that are normally expected to exist in the floodplain. Floodplains ofmost unconfined (or partly confined) alluvial rivers in natural conditions are typicallycharacterisedby somedegreeofmorphological and topographicheterogeneity related tothe presence of these geomorphic units. The absence of these features is therefore anindicator of alteration of the floodplain. These fluvial forms have an importantgeomorphological and hydraulic role, as well as an ecological relevance in determiningfloodplainhabitats.Theabsenceofthesefluvialformsisrelatedtoartificialmodifications,reworking and land use changes within the floodplain (e.g., urbanization, agriculture,infrastructures, flooddefenceschemes)and indicatesacertaindegreeofalterationofthemorphologicalfunctionalityoftheriver.Notethatthefloodplainevaluatedinthisindicatoristheentirefloodplain(modernfloodplainandpossiblerecentterraces).

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) Measurements: Remote sensing

The indicator isapplied topartly confinedorunconfinedchannels (anymorphologicaltype), for which some degree of lateral mobility in the past generating some fluviallandformsinthefloodplainisexpected.Eveninthecaseof‘passive’sinuousormeanderingrivers,althoughthecurrentenergyandrateofbankerosionmaybeextremely low,sometypical fluvial landforms in the floodplain (e.g.,minor/subdued ridge-swale topographyoroccasionalfloodplaindepressions)areexpected.

Theassessmentiscarriedoutbyremotesensing,andairborneLidardataareparticularlyusefulforthispurpose.Theindicatordoesnotevaluatethefrequencyorthearealextentoffluvialforms,butonlytheirpresence/absenceinthefloodplain.

ClassAisassignedtoreacheswithexistingtypicalfluvialformsoffloodplainsdevelopedduring the current hydrological regime conditions, i.e. in the case where these arehydrologicallyconnectedwiththechannel.ClassB isassignedtoreacheswherethefluvialforms in the floodplain are not contemporary but can potentially be reconnected byrestorationmeasures (e.g.excavationofsecondarychannels),orbynaturalmorphologicalrecovery (e.g. channel aggradation). To evaluate the potential to reactivate these fluvialforms,consistentlywiththeindicatorsofchanneladjustment(CA1andCA2),aerialphotosof1930s-1960speriodcanbeusedtoverifywhether these formswereactiveduring thattimeandthendisconnectedbybedincision.

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EXTENDEDANSWERS

Confinement type Partly confined or unconfined

A

Floodplain morphological heterogeneity in relation to the presence of geomorphic units expected for a given river type (for a full description of the floodplain characteristics and geomorphic units see Nanson and Croke (1992) and the Geomorphic Units survey and classification System). Braided (types 8, 9, 15) or high energy anabranching (type 10): undulating floodplain of abandoned channels and bars, swamps. Wandering (type 11): abandoned channels, swamps, braid-bars, islands, back channels. Sinuous or meandering with bars (types 13-14, 17-18) or pseudo-meandering (types 12, 16): flat to undulating floodplain surface, ridges and swales (scrolled floodplain), abandoned meanders, oxbow lakes, wetlands and swamps. Low-energy single-thread (types 20, 21): flat floodplain with low leveés, occasional crevasse channels and splays, occasional subdued ridge-swales particularly close to the channel, abandoned channels, floodplain lakes, wetlands and swamps. Low-energy anabranching (anastomosed) (types 19, 22): flat floodplain with extensive leveés, occasional crevasse channels and splays, abandoned anabranches, floodplain lakes, wetlands.

B Presence of traces of fluvial landforms in the floodplain (abandoned during the last decades), now not in connection with the present channel but with possible reactivation by interventions or recovery processes.

C Complete absence of floodplain morphological heterogeneity related to the absence of geomorphic units expected for a given river type.

ILLUSTRATEDGUIDE

ClassA ClassB ClassC

FigureA3.19Presenceoftypicalfluvialformsinthealluvialplain.ClassA:presenceofnaturalfluvialforms(e.g.abandonedmeander,oxbowlake).ClassB:tracesoffluvialforms,nowdisconnectedbythechannelduetoincision,butwithpossiblereactivation.ClassC:completeabsenceoffluvialformsinthealluvialplain.

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ClassA ClassC

ClassB

FigureA3.20Presenceoftypicalfluvialformsinthefloodplain.ClassA:meandering riverwitha recentcut-off.ClassC:meandering riverwithcompleteabsenceof landforms in theplain.ClassB:tracesofabandonedmeandersexits(photoontheleft),disconnectedfromthechannelbecauseofbedincision.Theobservationoftheaerialphotosofthe1950’s(photoonright)enablesverificationthattheseformshavebeenabandonedduringthelastdecades.

A3.3.9 F9:Cross-sectionvariability

DESCRIPTION

This indicator evaluates variability in the channel cross-section (in terms of channeldepth),thatisexpectedforthechannelmorphologyofthereachasaconsequenceofthepresenceandheterogeneityofgeomorphicunits.Themorphologicalheterogeneityofcross-sections is highly relevant for physical habitat diversity in many river systems. In fact,homogenous cross-sections are usually associated with altered conditions (except in thecase of Low-Energy reaches, which can naturally present a low diversity of forms). Suchalterations can be related to the presence of artificial elements (e.g. bank protections),channelmaintenanceinterventions(e.g.occasionalorperiodicchannelresectioning),ortohumanrelatedchanneladjustments(e.g.incisionduetosedimentstarvation).

Spatial scale Longitudinal: Site/Reach Lateral: Channel Measurements: Field survey and remote sensing

Theindicatorisappliedtoallchannelsubjecttoalltypesofconfinement.Inthecaseofconfinedchannels, theassessmentofthe indicatorfocusesonthecross-

sectionalvariabilityofwaterdepthandvelocity,mainlyexaminingthechannelbedandthensecondarilyitsbankswhere,inmostcases,thepresenceofzonesofflowseparationshould

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be expected. The indicator is applied exclusively in the field along one or morerepresentativesites.

Inpartlyconfinedorunconfinedchannels,theindicatorisappliedfromremotesensingandinthefield(cross-sectionaldepthvariability)alongoneormorerepresentativesites.

Inthecaseofstreamswithmedium-highenergy (e.g.ERTtypes8-14), thepresenceofpioneer islands, mainly along partly confined and unconfined channels, is an importantelementwhichcontributesconsiderably to thecross-sectionheterogeneity. In thecaseofbraided channels (types 8, 15), the depth variability in cross-section is naturally high(because of the multi-channel pattern), except in the case of interventions (e.g.resectioning, sediment or vegetation removal) which may maintain the overall braidingpatternbutaltertheheterogeneityincross-section.

InthecaseofLow-Energystreams(ERTtypes17-22)withnaturalabsenceofactivebarsand where the cross-section can be naturally quite homogeneous, the presence ofemergentmacrophytesandvegetatedmarginalbarsandbenchesare importantfeaturescontributingtotheexpectedhetereogenityinthecross-section,andtheirremovalcanaltersuchvariability.InLow-Energychannelscrossingplainsmodelledbyfluvio-glacialprocesses(e.g., in Northern Europe), heterogeneity in the cross section can be observed as aconsequenceofthenaturalvariabilityofbankandbedsediments(e.g.,fromfinematerialtoboulders).

Thepresenceofbankprotectionsisnotsufficientforevaluatingthechannelasalteredinterms of cross-sectional variability. In fact, these structures over time can becomemorphologicallymasked by vegetation and sediments, and therefore be characterised bynear-natural cross-section variability. The presence of these structures is nonethelessevaluated through the indicators of artificiality. If channel banks are strongly geometrical(e.g.nearverticalconcretewalls, regular ripraps), therelativechannel lengthoccupiedbybankprotections isconsideredasalteredonly inthecaseofstreamsfeaturingawidth-to-depthratio≤10,i.e.wherethebanksrepresentasignificantportionofthebankfullwettedchannel. In other terms, in wide channels – relative to their depth – the presence ofartificially regular banks alone is not sufficient for considering cross-section variability asaltered.

In the casewherealterations are located asymmetrically, i.e. only on one side of theriverchannel (e.g.presenceofbankprotectionstructuresonlyononebank inarelativelynarrowstream), thealtered reach length is countedasapercentageof thealteredbanksover the total bank length (sum of both banks) (e.g. an alteration along one bank for alengthof100mcorrespondstoanalteredreachlengthof50m).

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EXTENDEDANSWERS

Confinement type Confined

A

Absence or localized presence (≤ 5% of the reach length) of alterations of the natural cross-sectional variability along the entire reach: a natural variability of the cross section (channel depth/velocity) exists – in relation to the presence of bedforms, bars, vegetation, boulders, influence of hillslopes.

B Presence of alterations of the natural cross-sectional variability (channel depth/velocity) for a limited portion of the reach (≤ 33% of the reach length).

C Presence of alterations of the natural cross-sectional variability (channel depth/velocity) for a significant portion of the reach (> 33% of the reach length).

Confinement type Partly confined or unconfined

A

Absence or localized presence (≤ 5% of the reach length) of alteration of the natural cross-sectional variability (channel depth) along the reach: a natural altimetric variability in cross-section exists, in relation to the presence of geomorphic units (active side or point bars, pioneer or mature islands, secondary channels, natural banks, emergent macrophytes, vegetated bars and benches in Low-Energy streams).

B Presence of alteration of the natural cross-sectional variability (channel depth) for a limited portion of the reach (≤ 33% of the reach length).

C Presence of alteration of the natural cross-sectional variability (channel depth) for a significant portion of the reach (> 33%).

ILLUSTRATEDGUIDE

1 2

FigureA3.21Variabilityofthecross-section.(1)Pioneerislands,or(2)emergentaquaticmacrophytesandbenches,areimportantelementspromotingcross-sectionheterogeneityinmedium-highandLow-Energystreams,respectively.

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Confinedchannels

ClassA

ClassB

ClassB

ClassC

FigureA3.22Variabilityofthecross-sectioninconfinedchannels.ClassA:absenceofalterationsofthenaturalheterogeneityinthecross-section.ClassB(phototopright):alterationsforalimitedportionofthereach.ClassB(photobottomleft):alterationsonasubstantialportionofthereachbutonlyononeside(bankwall).ClassC:completealterationofthenaturalheterogeneityinthecross-sectionduetobankwallsonbothsides.

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Partlyconfinedandunconfinedchannels

1

2

FigureA3.23Alterationofcross-sectionvariabilityinpartly-andunconfinedchannels.(1)Casesofpartialhomogenizationofthecross-sectiondueto interventions.(2)Cross-sectionhomogeneityextendedforlongreachesduetoexcessiveartificiality.

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ClassA

ClassB

ClassC

FigureA3.24Variabilityofthecross-sectioninpartly-andunconfinedchannels.Examplesformulti-thread,transitional,andsingle-threadchannels.ClassA: absenceof alterations.ClassB: alterations for aportion≤33%of the reach length.ClassC: alterations for aportion>33%ofthereachlength.

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A3.3.10 F10:Structureofthechannelbed

DESCRIPTION

Astreaminnaturalconditionsexhibitsheterogeneityofbothbedandbarsedimentsize,structure and texture, except in some specific cases (i.e. confined bedrock channels orstreams with fine bed sediment). The structure and heterogeneity of the channel bedsediment have several implications for the functionality of bedload processes and flowresistance,andareextremelyimportantforthecharacteristicsofaquaticphysicalhabitats.This indicator takes into account possible alterations of the bed sediment, such asarmouring,clogging,substrateoutcrops,burialofriverbedandbedrevetments,relatedtomorphological adjustments (e.g. bed incision or excessive aggradation due to anthropicinterventions)ordirectlytohumaninterventions(e.g.revetments).Armouringreferstothepresenceofasurfacelayerinwhichbedmaterialsizeissignificantlycoarserthanthesub-layer. Clogging refers to an excess of fine sediments (potentially linked to excessive soilerosion because of land use changes, or to alterations of hydrological regime) causinginterstitialfillingofthecoarsesedimentmatrixandpotentiallysmotheringthechannelbed(“blanket”: Brierley and Fryirs, 2005, or “embeddedness”: Sennatt et al., 2008). Burial orsiltation is a special type of aggradation, where finer sediments (e.g. silt and sand) aredepositedinasufficientlythicklayertoburyacoarser(e.g.gravel)riverbed.Burialhasnotonlydirectecologicaleffects,butitalsohasmorphologicaleffects,sinceitburiesbedformsand so simplifies bed morphological complexity. Similarly to clogging, burial is generallyassociated with an excessive input of fine sediments to the river channel caused byextensivebankerosionorsoilerosionrelatedtoagriculturalactivity,landusechanges(e.g.deforestation)orreleaseoffinesedimentsfromdams.

Spatial scale Longitudinal: Multiple sites - reach Lateral: Channel Measurements: Field survey

This indicator is applied to confined channels with a mobile bed as well as partlyconfined and unconfined channels. It is not applied to bedrock and colluvial confinedchannels,orsand-bed rivers,becauseof theirnaturalbedsubstratehomogeneity,and inthecaseofdeep,non-wadeablerivers,asitisnotpossibletovisuallyobservethesubstrate.

There are differences between the cases of confined channels and partly confined orunconfined channels. In the former case, armouring is not considered as an indicator ofalteration, because confined channels with a mobile bed have a naturally strongheterogeneity of sediments. Therefore, armouring is assessed only in the case of partlyconfined and unconfined channels. For partly confined and unconfined channels, someheterogeneityofbedsubstratesize isalsoconsideredasnormal,asaconsequenceofthevariabilityofmorphologicalunits (bars,baseflowchannels, riffles,pools),aswellaswithinthe same unit. However, a pronounced armouring is considered as an alteration (seebelow). Similarly, the presence of clogging can be normal in particular situations (e.g. insomepoolsoralongastreamclosetohillslopescomposedofclay),butitisconsideredanalterationwhenitisevidentandpresentinvariousportionsofthereach.InthecaseofveryLow-Energystreamsthatarecharacterisedbyfinebedsediment,where,asaconsequence,armouring and clogging can not occur, the evaluation of the indicator is based on the

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possible occurrence of bedrock outcrops, burial, or revetments (class B is thereforeexcludedforLow-Energyrivers).

Afieldevaluationisnecessaryforthisindicator.Theevaluationcanstartfromaseriesofrepresentative sites to ensure that various portions of the reach are assessed. In manycases, theassessmentperformedatanumberofsites issufficient todeterminetheclass,but inmoreproblematic cases (for example, in the caseof contrastingevidence), a rapidreconnaissancealongthewholereachmaybenecessary.

A quantitative assessment of armouring would require sediment sampling andmeasurements of the surface layer and sub-layer, which are beyond the scope of thisprocedure.Thereforearmouring,aswellasclogging,arevisuallyassessed.Anevaluationisnecessary,atleastalongthevisitedsites,ofthepercentageinlengthoftheportionsofthereach altered by armouring or clogging. Clogging and/or armouring are unlikely to occuracross thewhole bed surface and all the geomorphic units. For example, clogging is notnormally expected across unitswith relatively high flow velocity (e.g., rapids, steps), andarmouring is also uncommon on unitswith low flow velocity (e.g., pools). Therefore, if aportion of the reach shows evidence of armouring (or clogging) across most of thegeomorphic units where has the potential to occur, the entire length of this portion isconsideredasaltered.

Theassessmentofburial requiresthattheoperatorwadestheriveratsomepointandusesarodtoverifywhetheracoarsersubstrate(e.g.gravelorsandygravel)existsbelowasurficial layerof fine sediments (clay, silt, sand).Burialdiffers fromclogging, inwhich thecoarsesubstrateisvisiblebutwithaninterstitialfillingbyfinersediment(typicallysiltandclay). In thecaseofburial theoriginalbedsubstrate iscompletelyburiedbyasufficientlythicklayer(i.e.atleast2cm)offinersediment.

Anadditionalelementofalterationisbedrockoutcropping.However,itrequirescarefulevaluation, especially in the case of confined channels, where it is considered as analteration only when it is evidently related to bed-incision due to human causes, forexample when there is evidence or information of a previous alluvial substrate that hasbeen completely removed due to bed incision. Even in the cases of partly confined andunconfined channels, an alteration is taken into consideration only when this is clearlyrelatedtobed-incisionduetohumancauses,that is, inalluvialreacheswithamobilebedsufficiently far from the hillslopes. It must be excluded, however, in those cases withhillslopesnot far fromthechannel,wherenaturaloutcropscanoccur.When thebedrockoutcropping is related to recent bed-incision due to human causes, this determines theassignationtoclassC1(occasionaloutcropping)orC2(widespreadoutcropping,i.e.>33%).Bedrockoutcroppingmustbeevaluatedatthereachscale.

Finally,thewidespreadpresenceofbedrevetments (>33%)determinestheassignationtoclassC2.Asforbedrockoutcropping,thismustbeevaluatedatthereachscale.

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EXTENDEDANSWERS

Confinement type Partly confined or unconfined Range of application

Not evaluated for bedrock or colluvial (ERT types from 1 to 3), or for deep rivers when it is not possible to observe the channel bed

A Natural heterogeneity of bed sediments in relation to the different sedimentary units (steps, pools, riffles, etc.), with absence of or localized situations of clogging.

B Evident clogging occurring along ≤50% of the reach length.

C1

Evident and widespread clogging occurring along > 50% of the reach length, or evident burial occurring along ≤50% of the reach length, or occasional substrate outcrops (≤ 33% of the reach length) related to recent bed-incision of the alluvial substrate (for human causes).

C2

Evident and widespread burial occurring along > 50% of the reach length , or widespread substrate alteration by bed revetments (any type) (> 33% of the reach length), or widespread substrate outcrops (> 33% of the reach length) related to recent bed-incision of the alluvial substrate (for human causes).

Confinement type Partly confined or unconfined

Range of appl ication Not evaluated for deep rivers when it is not possible to observe the channel bed

A Natural heterogeneity of bed sediments in relation to the different sedimentary units (bars, channel bed, pools, riffles, etc.) and also within the same unit, with absence of or localized situations of armouring and/or clogging.

B Evident armouring or clogging occurring along ≤50% of the length.

C1 Evident and widespread armouring or clogging occurring along > 50% of the length, or evident burial occurring along ≤50% of the reach length, or occasional substrate outcrops (≤ 33% of the reach length) related to incision of the alluvial substrate.

C2

Evident and widespread burial occurring along > 50% of the reach length , or widespread substrate outcrops (> 33% of the reach length) due to incision of the alluvial substrate or widespread substrate alteration by bed revetments (any type) (> 33% of the reach length).

ILLUSTRATEDGUIDE

1a

1b

2

FigureA3.25Sometypesofalterationsofthesubstrate.(1)Armouring(a:superficiallayer;b:sub-layer).(2)Clogging.

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Confinedchannels

ClassA

ClassBorC1

ClassC2

FigureA3.26Alterationofsubstrateinconfinedchannels.ClassA:naturalheterogeneityofsubstrateinaconfinedchannel.ClassBorC1:presenceofclogging(theassignationtoClass B or C1 will depend on its extension in the reach). Class C2: complete alteration of substrate because ofwidespreadbedrevetments.

Partlyconfinedandunconfinedchannels

ClassA

ClassBorC1

FigureA3.27Alterationsofsubstrateinpartly-andunconfinedchannels.ClassA:naturalsedimentheterogeneityinanunconfinedchannel.ClassBorC1:presenceofarmouring(photoonleft)or clogging (photoon right) (assignation toClassB orC1will dependon theextensionof armouringand/or cloggingalong the reach).Class C2: bedrock outcroppings due to bed incision (photo on left) or completely altered substratebecauseofbedrevetment(photoonright).

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ClassC1

Figure A3. 27 (continued) Class C2: bedrock outcroppings due to bed incision (photo on left) or completely alteredsubstratebecauseofbedrevetment(photoonright).

A3.3.11 F11:Presenceofin-channellargewood

DESCRIPTION

Anevaluationiscarriedouttodeterminewhetheralteredconditionsexistcomparedtotheexpectedpresenceof largewoodalong the reach. Largewood includes trees, trunks,branches,rootwadshavingalength>1manddiameter>10cm.Thismaterialhasseveraleffects on geomorphic-hydraulic processes, and has various implications for ecologicalprocesses (habitatdiversity, inputoforganicmatter,etc.).On theotherhand, it iswidelyrecognizedthatthismaterialmayrepresentanadditionalfloodhazardfactor.

Spatial scale Longitudinal: Multiple sites - reach Lateral: Channel Measurements: Field survey

The indicator is evaluated for both types of streams (confined and partly confined -unconfined), but is not applied in tundra areas in northern Europe, where woodyvegetationisnaturallyabsent.Giventhehighspatialandtemporalvariabilityofthequantityof wood material, it is not possible to define precise values for the number of woodyelementstoobserve.Areach,oraportionofit,isevaluatedasalteredwhenthepresenceofwoodisextremelylimitedorcompletelyabsent(approximately<5elementsevery100mofchannellength).

Theoperatorcarriesouttheevaluationbasedonfieldobservations.Insomecases,thepresenceofwoodcanbealteredonlyforaportionofthereach(forexamplewheretherehasbeenaremovalofwoodinonlypartofthewholereach).Thereforefieldobservationsmustbecarriedoutonasufficientnumberofsitesinordertosufficientlyassessthewholereach.When,inallthevisitedsitesasignificantpresenceofwoodisobserved,thereachcanbeassigned toclassA.Wherewood isabsent inoneormore sites (or there isextremelylimited presence), then an evaluation of the extent of the reach with absent wood isnecessarytodeterminewhethertoassignthereachtoclassBorC(seeextendedanswers).In some cases (very high resolution images), remote sensing can be useful, and theevaluationcanbecarriedoutforgreaterreachlengthsandeventuallyatthereachscale.

Theevaluationareaincludesthechannel(includingislands)andthebanks(woodonthefloodplainisnotconsidered).Additionalrulesaccountingforparticularsituationsofnaturalwoodscarcityconcernthecaseoflargerivers(bankfullwidth>meantreeheight),relatively

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deep(meanbankfulldepth>meantreediameter),withfewsizeablebarsand/orboulders.Theseareconsideredas“transport”reaches,i.e.wheredepositionisnotlikely.Thisisthecase for relatively large rivers with plane bed morphology (confined) or single-threadchannels, where some large wood should be present along the banks, except in case ofrockybanksand/orwithanaturalabsenceoftreevegetation.Intheselattercases,classAisassigned.

Lastly, the indicator isnotevaluated for reachesabovethetree-lineorwhereriparianvegetation is completely absent due to natural factors in the reach and in the upstreamreaches. The indicator is evaluated in reacheswhere thevegetation is locally absent (e.g.localhillslopebanks),becauseacertainamountofwoodisexpectedtobesuppliedfromtheupstreamreaches.

EXTENDEDANSWERS

Confinement type All types

Range of appl ication Not evaluated above the tree-line and in streams with natural absence of riparian vegetation, such as in north-european tundra

A

Significant presence of large wood (entire plants, trunks, branches, root wads) within the channel and/or on the banks along the whole reach. Or absence of large wood in case of reach of wood transport (bankfull width > mean tree height, bankfull mean depth > mean tree diameter, absence of significant obstacles, e.g. bars and large boulders).

B Very limited presence or absence of large wood for ≤ 50% of the reach length C Very limited presence or absence of large wood for >50% of the reach length.

ILLUSTRATEDGUIDE

Class A

FigureA3.28Presenceoflargewood.ClassA:naturalpresenceoflargewoodinasteepconfinedchannelwithlimitedwidthand(cascade,firstrowonleft),and in a wider and less steep confined channel with (plane bed morphology, center); natural absence of riparianvegetationandlargewoodbecausethereachisabovethetree-line(right);naturalpresenceoflargewoodinunconfinedchannels(photosincentralrow).

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ClassBorC

FigureA3.28(continued)Presenceoflargewood.ClassBorC:examplesofchannelswithabsenceoflargewoodbecauseofrecentinterventionsofremoval(photosinthelowerrow)(assignationtoClassBorCwilldependontheextensionofthealterationalongthereach).

Vegetationinthefluvialcorridor

The next two indicators (F12 and F13) concern the naturally functioning riparianvegetation,i.e.theexpectedwoodyandshrubvegetationtypicallywithapatchy,mixed-agestructure, and freely interacting with fluvial processes (erosion, sedimentation, flooding).ThevegetationassessedbytheindicatorF12isnotlimitedtotheriparianzoneimmediatelyadjacenttotheriverbanks,butisextendedtotheoverallrivercorridor.Thelatterincludesthe area extending from the channel to the hillslopes (or the old terraces), theoreticallyincludingtheentire floodplain,andthat is functional tothenormalgeomorphicprocesses(flowresistance,bankstabilization,woodrecruitment,sedimenttrapping,etc.).

Only the geomorphic functioning of the vegetation is considered, so speciesidentificationisnotrequired.Thewidthoffunctionalvegetationinthefluvialcorridorandlinear extension along the banks are themain aspects taken in consideration since thesefactors are the primary determinants of their level of interactionwith themorphologicalprocesses of erosion, sedimentation and flooding.Commercial short-rotation plantations(e.g. Populus sp., Eucalyptus sp., Paulownia sp., conifers etc.) are considered aspartiallyfunctional, as they are characterized by lower tree densities thannatural riparian forestsandconsequentlydonot fullyperformtheirgeomorphic functions. In suchcases,a lowerscore is assigned to this typeof vegetation, i.e. it is countedas corresponding to50% (ofwidth or extension, for F12 and F13 respectively) of functional vegetation. Other, lowdensity, commercial plantations of woody vegetation (e.g. olive tree, grape vines, appletrees, etc.) are considered as not functional. However, non-commercial reforested areasthat are characterized by higher tree densities, comparable to those of naturally-formedriparianwoodland,areconsideredtobefullyfunctional.

Inordertobeconsideredasfunctional,woodyvegetationshouldbefullyconnectedtothe relevant geomorphic processes (i.e. flooding, sediment erosion and deposition).Therefore, vegetation separated from the river by artificial levées is excluded, whereasvegetation bordering protected (artificially reinforced) river banks is taken intoconsiderationbecause it can stillbe floodedallowing it toprovide flow resistance, supplywood,andtrapsediment.Inthecaseofconfinedchannels,roadsinterruptthisconnection(similarlytotheartificialleveesforunconfinedchannels).

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IndicatorsF12andF13arenotappliedabovethenaturaltree-line.InItaly,forexample,thislimitisquitevariable,(approximatelyaround1,800÷2,300ma.s.l.)and,inmanycases,grazing has lowered this limit: in such a case, it is considered as an alteration. The twoindicators are not applied in the case of areas of tundra in northern Europe, wherevegetation is naturally absent. Lastly, in the caseofparticular climatic and soil conditionssuch as inMediterranean regions, dense woody vegetationmay not develop within theriver corridor, and so a sparse cover of trees and shrubs canbe considered as functionalvegetation.

1

2

FigureA3.29Vegetationinthefluvialcorridor(1)Presenceofvegetationconnectedwiththechannelinapartlyconfinedreach;(2)absenceofvegetation(right)orvegetationdisconnectedbythestreamchannelbecauseofthepresenceofwalls.

A3.3.12 F12:Widthoffunctionalvegetation

DESCRIPTION

This indicator assesses the average width (or areal extension) of functional riparianvegetation in the fluvial corridor directly connected with the channel. In the case ofconfinedchannels, the functionalwidth isevaluatedalong theportionsof floodplain thatarepotentiallypresent,andalongtheadjacenthillslopesforastripof50moneachsideoftherivercorridor(startingfromthebaseofthehillslopesasinthecaseofF3),excludingthecasesofnear verticalhillslopesorwhere landslidesarepresent,wherewoodyvegetationmaybenaturallyabsent.Inthecaseofpartlyconfinedandunconfinedchannels,thewidthoffunctionalvegetationisevaluatedasafunctionofchannelwidth.

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (partly confined / unconfined);

Floodplain/ adjacent hillslopes (confined) Measurements: Remote sensing

The evaluation is carried out by remote sensing and GIS analysis, by delimiting thewoody/shrubvegetationintherivercorridor,uptoalimitof50minthecaseofconfinedchannels.Thewidthincludesthevegetationonbothsidesofthechannel.Notethatislandswithin the channel are included in the computation (including the case of anabranchingchannels), reflecting their potential contribution in terms of flow resistance, sedimenttrapping and large wood delivery. In the case of partly confined channels, where the

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functionalvegetationoccupiestheentireavailablewidth(i.e.theentirefloodplain),classAisattributed to the reacheven if thewidthof the functionalvegetation is lower thannW(seetablebelow).

Partially functionalvegetation (e.g.Populussp.,Eucalyptus sp.,Paulowniasp.,conifersetc.)isconsideredascorrespondingto50%inwidth(orarea)offunctionalvegetation.

EXTENDEDANSWERS

Confinement type All types

Range of application Not evaluated above the tree-line and in streams with natural absence of riparian vegetation, such as in north-european tundra

A

A high width of functional vegetation: for confined channels, connected functional vegetation occupying > 90% of hillslopes (50 m for each side, excluding portions with rock or landslides) and the adjacent floodplain (if present). The functional vegetation includes woody tree or shrub species with significant cover (i.e. > 33% of the width). In Mediterranean regions, functional vegetation can only include spontaneous shrub species. for partly confined - unconfined channels, connected functional vegetation with a total width (sum of the two sides) of at least nW, where W is the channel width, n = 2 for single-thread or anabranching channels (types 10, 12-14, 16-22), n = 1 for braided or wandering channels (types 8, 9, 11, 15). The functional width includes either woody and shrub species, with a significant presence of the former (> 33% of the width occupied by woody vegetation). In Mediterranean regions, functional vegetation can only include spontaneous shrub species.

B

A medium width of functional vegetation: for confined channels, connected functional vegetation occupying 33÷90% of hillslopes (50 m for each side, excluding portions with rock or landslides) and the adjacent floodplain (if present). The functional vegetation includes woody tree or shrub species with significant cover (i.e. > 33% of the width). Or, as in case A, but with largely prevailing shrub species (i.e. woody vegetation ≤ 33% of the functional width) except for specific climatic contexts (e.g. Mediterranean regions), where woody vegetation may not naturally develop. for partly confined - unconfined channels, connected functional vegetation with a total width (sum of the two sides) between 0.5W and nW, where W is the channel width, n = 2 for single-thread or anabranching channels (types 10, 12-14, 16-22), n = 1 for braided or wandering channels (types 8, 9, 11, 15). Or, as in case A, but with largely prevailing shrub species (i.e. woody vegetation ≤ 33% of the functional width).

C

A limited width of functional vegetation: for confined channels, connected functional vegetation ≤ 33% of hillslopes (50 m for each side, excluding portions with rock or landslides), and of adjacent plain (if present). The functional vegetation includes woody tree or shrub species with significant cover (i.e. > 33% of the width). Or, as in case B, but with largely prevailing shrub species (i.e. woody vegetation ≤ 33% of the functional width) except for specific climatic contexts (e.g. Mediterranean regions), where woody vegetation may not naturally develop. for partly confined - unconfined channels, connected functional vegetation with a total width (sum of the two sides) ≤ 0.5W (any channel typology), where W is the channel width. Or, as in case B, but with largely prevailing shrub species (i.e. woody vegetation ≤ 33% of the functional width).

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ILLUSTRATEDGUIDE

Confinedchannels

ClassAVEGETATIONWIDTH>90%OFTHE50MSTRIP

ClassBVEGETATIONWIDTH33÷90%OFTHE50MSTRIP

ClassCVEGETATIONWIDTH≤33%OFTHE50MSTRIP

FigureA3.30Widthoffunctionalvegetationinconfinedchannels.ClassA:thevegetationcorridoroccupies>90%oftheplainandadjacenthillslopes(forastripof 50mforeachside,representedbythedottedblackline).ClassB:thevegetationcorridor isbetween33and90%.ClassC:thevegetationcorridorisextremelylimited(≤33%).

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Partlyconfinedandunconfinedchannels

ClassAVEGETATIONWIDTH>nW

ClassBVEGETATIONWIDTH0.5W÷nW

ClassCVEGETATIONWIDTH≤0.5W

FigureA3.31Widthoffluvialcorridorinpartly-andunconfinedchannels.Class A: the vegetation corridor is sufficiently wide, having a width > nW (W: mean channel width); Class B: thevegetation corridor has amediumwidth, being included between 0.5W and nW; Class C: the vegetation corridor isextremelynarrow,havingawidth≤0.5W.

ILLUSTRATEDGUIDE

ClassA ClassB ClassC

FigureA3.32Widthoffunctionalvegetationinpartlyconfinedandunconfinedchannels.Class A: the vegetation corridor is verywide compared to the channelwidth.Class B: the vegetation corridor has amediumwidth.ClassC:thevegetationcorridorisalmostabsent.

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A3.3.13 F13:Linearextensionoffunctionalvegetation

DESCRIPTION

This indicator evaluates the longitudinal continuity of functional riparian vegetationalong thebanks, expressed as a percentageof the length coveredby riparian vegetationagainstthetotallengthofthereach(bothbanks),andforanyarealextension.Theindicatorrefers to the functional riparian vegetation in the river corridor zones external to thechannel,thereforeislandsarenotconsidered,exceptinthecaseoflargeislandsseparatinganabranchchannelsinanabranchingrivers.Linesofornamentaltreesonthechanneledgeare considered as partially functional, and so they are treated in the same way ascommercialplantations(seepreviousindicator).

Spatial scale Longitudinal : Multiple sites – reach Lateral : Banks Measurements: Remote sensing

Theevaluationof the linearextensionof riparianvegetation is carriedoutby remote

sensing andGIS analysis. The same delimitation of woody/shrub vegetation in the rivercorridorconnectedwiththechannelcarriedoutforF12isused,measuringthelength(sumofthetwobanks)indirectcontactwiththechannel.Thislengthiscomparedwiththetotalpotential length(sumofthetwobanks)wherefunctionalvegetationcouldbepresent(i.e.excluding portions of banks comprised of rock or affected by landslides). In the case ofanabranching channels, the length is evaluated for all anabranch channels and the totalpotentiallengthisthesumofthebanklengthsofalltheanabranches.Whenremoteimagesaredifficulttointerpret(e.g.forconfinedchannels),asitescalecheckmayberequired(e.g.toidentifybankscomprisedofrock).

Partially functionalvegetation (e.g.Populussp.,Eucalyptus sp.,Paulowniasp.,conifersetc.)isconsideredascorrespondingto50%inlinearextensionoffunctionalvegetation.

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ILLUSTRATEDGUIDE

ClassAVEGETATIONLINEAREXTENSION>90%

ClassBVEGETATIONLINEAREXTENSION33÷90%

ClassCVEGETATIONLINEAR

EXTENSION≤33%

ARTIFICIALLEVÉES

FigureA3.33Linearextensionofthefunctionalriparianvegetationalongthebanks.ClassA:thelinearextensionisveryhigh(>90%ofthetotallengthofbothbanks).ClassB:thelinearextensionislowerthan90%buthigherthan33%.ClassC:althoughavegetationcorridorexists forabouthalfof thereach,mostof it isdisconnectedbecauseoftheexistenceofartificiallevées.

EXTENDEDANSWERS

Confinement type All types

Range of application Not evaluated above the tree-line and in streams with natural absence of riparian vegetation, such as in north-european tundra

A

Linear extension of connected functional (riparian) vegetation for > 90% of maximum available bank length (i.e. sum of both banks excluding those comprised of rock or landslides). Presence of either tree or shrub species (> 33% of the length of functional vegetation). In dry Mediterranean regions, functional vegetation may only include spontaneous shrub species. In the case of presence of anabranches, the reach length is the sum of the lengths of the anabranches.

B

Linear extension of connected functional vegetation for a length of 33÷90% of maximum available length (i.e. sum of both banks excluding those in rock or landslides). In the case of presence of anabranches, the reach length is the sum of the lengths of the anabranches. Or, as in case A, but with shrub species largely prevailing (woody species ≤ 33% of the length of the functional vegetation).

C

Linear extension of connected functional vegetation for a length of ≤ 33% of maximum available bank length (i.e. sum of both banks excluding those comprised of rock or landslides). In the case of presence of anabranches, the reach length is the sum of the lengths of the anabranches. Or, as in case B, but with shrub species largely prevailing (woody species ≤ 33% of the length of the functional vegetation).

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A3.4 ArtificialityUpstreamalterationoflongitudinalcontinuity

Thefirstfourindicatorsofartificialityconsiderthealterationofthedrivingvariablesforchannel morphology, which are water discharges and sediment transport. It is useful toconceptuallyseparatethealterationsofthesamevariablesoccurringupstreamfromthoseoccurring within the reach. Indicators A1 and A2 are the only two concerned with theconditionsexistingupstream (catchment scale)of theanalyzed reach,while thenext twoindicatorsA3 andA4 concern the alterations of the same characteristics, but within thereach.

Forthispurpose,inthecaseofastructure(e.g.adam)locatedattheboundarybetweentwo reaches (e.g. between an upstream reach n1 and a downstream reach n2),conventionallythestructureisassignedtotheupstreamreach(Figure34).However,whiletheeffectsofthestructureareconsideredasalterationsinthereach(bytheindicatorsA3andA4) for the upstream reach n1, they are accounted as upstream alterations (by theindicatorsA1andA2)forthedownstreamreachn2.

Consider the effects of the

structure on the reach (n2) Assign the structure to

the upstream reach (n1)

FigureA3.34Ruleforassigningatransversalstructurethatcoincideswiththelimitbetweentworeachesanditseffectsonthealterationofsedimentandwaterdischarges.

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A3.4.1 A1:Upstreamalterationofflows

Thisindicatorevaluatestheoverallalterationsofflowsoccurringupstreamofthereach.Theindicatorissplitintotwosub-indicatorsasfollows:

1.A1M:evaluatespossiblealterationsofflowconditionswhichmayhaverelevanteffectsonchannel morphology (i.e. may cause changes of the bankfull channel size because ofmorphologicaladjustments).Theuseof thissub-indicatoralonepermitscalculationof theMorphologicalQualityIndex(MQI).

2. A1H: concerns evident flow alterations, which, although impairing some biologicalprocesses,mayhavesmalleffectsonchannelmorphology(i.e.maycausechangesofsomeofthegeomorphicunits,butnothavingsignificanteffectsonthebankfullchannelsize).Theuse of this sub-indicator, in addition to the previous one, allows the calculation of theoverallHydro-MorphologicalQualityIndex(HMQI).

Spatial scale Longitudinal: Upstream catchment Lateral: Entire floodplain (including recent terraces) Measurements: Map layer of interventions, remote sensing A3.4.1.1A1M:Upstreamalterationofflowswithpotentiallyrelevanteffectsonchannelmorphology

DEFINITION

This indicator evaluates possible alterations of flow conditions which may have asignificant effect on morphological processes. Therefore, the main emphasis is on thereductionor increaseof channel-formingdischarges and/ordischargeswithhigher returnintervalsaffectedbyinterventionsatthecatchmentscale,suchasdams,impoundment(i.e.water retentionbyweirs), dischargediversionsorwater abstractions, spillways, retentionbasins,etc.Specificcasesofalterationoflowflows(releaseofconstantflowsdownstreamofdams)mayalsohavemorphologicaleffectsandsoarealsoconsidered.

The indicator does not directly evaluate the effect of these structures on sedimentdischarge,whichisassessedbythefollowingindicator(A2).Inthecaseofadiversionwherethewater is returned to a downstream reach, only the river portion between thewaterdiversion and the restitution is considered as altered. The indicator is not applied to themostupstreamreachofariver,exceptwhenthewaterdiversionoccursatthesource.

Identification of existing interventions having effects on discharges can be carried outusingamaplayerofinterventionsandremotesensing.Thisindicatoralsorequiresdataandinformation about the management of the structures (e.g. dams) and their effects ondischarges. This canbe achieved fromagencies in chargeof the rivermanagement.Notethat this type of information and hydrologic data collected at the catchment scale is anessentialpartofthePhase1(generalsetting-up),andthisknowledgeisthenusedforallthereachesofagivencatchment.

Alsonotethatthis indicatorcanbeestimatedstartingfromthedatarequiredtoassessthealterationsof thehydrological regimeby specific indices (e.g. IAHRIS, IARI,QM-HIDRI,etc.).

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ToevaluatetheindicatorA1,threebroadclassesofdischargeareconsidered:(1)channel-formingdischarges(returnintervalfrom1.5to10years);(2)dischargeswithareturninterval>10years;(3)flowsbelowchannel-formingdischarges.1.Channel-formingdischarges(returnintervalRIfrom1.5to10years).Theseareintendedasthedischargeshavingthemostrelevanteffectsonchannelmorphology.AvalueofQ1.5isconventionallyusedheretorepresentthechannel-formingdischarge.However,therangeofdischargeswithimportanteffectsonchannelmorphologycanbewidenedtoreturnintervalsoftheorderof10years.Infact,inbraidedorwanderingmorphologies,therearedifferentvalueswhichcanaffectchannelform,withislandsbeingmodelledbydischargeswithareturnintervalupto10years.Furthermore,inthecaseofsteepandarmouredmountainstreams,onlydischargeswithreturnintervals>2÷3yearsareingeneralabletodeterminerelevantprocessesofsedimenttransport(exceptinthecasesofnaturalhighbedloadsupply),andthemorphologicalchannelconfigurationisdeterminedbyevenhigherdischarges.2.Dischargeswithreturninterval(RI)>10years.Thesealsohaverelevantmorphologicalandhydrauliceffects,althoughtheireffectonchannelmorphologyislowerthanthechannel-formingdischarge,becauseoftheirlowerfrequency.Thereareinterventionswhichonlyhaveaneffectondischargeswithahighreturninterval,astheyaredesignedtostartworkingonlyaboveagiventhreshold(e.g.spillways,retentionbasins,somedams).3.Flowsbelowchannel-formingdischarge(returnintervalRI<1.5years).Thisclassincludestherangeofdischargewhichvariesfromlow-flowconditionstosmallormoderatefloweventsbelowchannel-formingflows.Lowflowsbelowthresholdconditionsoferosionandsedimenttransportareconsideredtohavenegligibleeffectsonchannelmorphology.Anotableexception,whichisaccountedforbyindicatorA1,isrepresentedbywaterregulationbydams,i.e.thereleaseofarelativelyconstantdischarge,higherthannaturalflow.ThiscaseisparticularlyapplicabletoriverscharacterizedbyatypicalMediterraneanhydrologicalregime(i.e.highflowvariabilityandlow-waterlevelduringthesummer).Forsuchcases,someauthorsobservedthattheincreaseoflow-flowdischargefromdamsandreservoirsmayhaveageomorphologicalimpactonchannelgeometryanddynamics(Johnson,1994;MagdalenoandFernandez,2013;GarofanoGomezetal.,2013;PettsandGurnell,2013).Infact,theincreaseofthewaterlevelduringthesummerinriverswhicharenormallydryorwithverylowflows,caninduceariseinthewatertableandpromotevegetationencroachmentacrossthechannel,promotingchannelnarrowing.

Dataneededforestimatingthedischargeswithgivenreturnintervals,andinformationtoevaluatetheeffectsofinterventionsonsuchdischarges,areoftennotavailable.Therefore,twoprocedurescanbeconsidered,accordingtotheiravailability,asfollows.

1.Dataavailable

Amorerigorousandquantitativeprocedureisonlyapplied,wheredataisavailable,totheevaluationofalterationsonchannel-formingdischargesand/orhigher.Possiblealterationsof flows below channel-forming discharge, restricted to the specific case of prolongedreleaseofincreasedflowsdownstreamfromadam,areevaluatedonlyqualitatively.First,itisnecessarytoevaluateifandhowmuchanyinterventionexistingupstreaminthecatchmentproducesalterationsonthechannel-formingdischargesand/ordischargeswithreturninterval>10years.

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1.Channel-formingdischarges.EstimationofQ1.5anteorpostoperam(orofotherQwithRIbetween1.5and10years)canbeobtainedbyastatisticalanalysisofasufficientlylongseriesofmaximumannualpeakdischarges,fromtheclosestgaugingstationtothereach,oronthebasisofrainfall–runoffmodelsormodelsofregionalizationofdischarges(theseestimationsareoftenavailableatthepublicagenciesresponsiblefortherivermanagement).Normally,thisanalysisisperformedonlyontheQ1.5,butinsomecases(e.g.braidedriversormountainstreams)furtheranalysisondischargeswithRI=10yearsmaybenecessary.Whentherearesignificantchanges(>10%)inthesedischargesduetoartificialinterventions,thereachisassignedtoclassC.Example.Q1.5=300m3/sandareservoirexistingupstreamhastheeffectofreducingthisdischargebyabout60m3/s.2.DischargeswithRI>10years.Inthecaseofupstreaminterventionsaffectingthisclassofdischargeandproducingsignificantchanges(>10%),thereachisassignedtoclassB(evenwherenochangesinthechannel-formingdischargeoccur).Example.PresenceofaretentionbasinupstreamdesignedtoworkonlyfordischargeswithRI>20years,andproducingareductionof30m3/s,comparedtoaQ20estimatedtobeabout150m3/s.3.Flowsbelowchannel-formingdischarge.Inthecaseofprolongedreleasesofincreasedflowsdownstreamadam,specificallyduringthedryseasonsofMediterraneanregime-dominatedrivers,producingevidenteffectsonvegetationandchannelmorphology,thereachisassignedtoclassB.

Shouldanyofthepreviousalterationsnotbeoccurring,thereachisassignedtoclassA.

ThelogicalsequenceofassessmentissummarisedinTable3andFigure35.TableA3.3DefinitionoftheclassesfortheindicatorA1.

ΔQ1.5-10 ΔQ (RI > 10 years) Low f lows

A ≤ 10% ≤ 10% No morphological effects

B ≤ 10% > 10% and/or increased low flows downstream of dam

C > 10% Any case Any case

FigureA3.35FlowchartoftheindicatorA1.

ΔQ1.5-10>10%? A1 in C Yes

No

A1 in B Yes

No

A1 in A

ΔQ (RI>10 years) >10%?

A1 in B Yes

No

Increased low flows downstream dams?

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EXTENDEDANSWERS

Confinement type All types

A

Absence of interventions altering water discharge (dams, spillways, diversions, retention basin, etc.) or interventions however with no significant effects (induced changes ≤ 10%) on channel-forming discharges (return interval RI from 1.5 to 10 years) and on discharges with RI > 10 years.

B

Presence of interventions (dams, spillways, diversions, retention basin, etc.) having significant effects (induced changes > 10%) on discharges with RI > 10 years, but with no significant effects (≤ 10%) on channel-forming discharges. Or release of increased low flows downstream dams during the dry seasons of Mediterranean regime-dominated rivers, producing evident effects on vegetation and channel morphology.

C Presence of interventions (dams, spillways, diversions, retention basin, etc.) having significant effects (induced changes > 10%) on channel-forming discharges.

2.Datanotavailable

In such a case, a simplified procedure is adopted that is based on the type ofintervention and on available information about its use (e.g. dam for hydropowerproductionorforretentionpurposes),describedasfollows.Casesofprolongedreleasesofincreased flowsdownstreamofadamareevaluated in the samewayas for thepreviouscase(dataavailable).

EXTENDEDANSWERS

Confinement type All types

A Absence of interventions altering water discharge, or existence of interventions, but with no effects on channel-forming discharge and on discharges with higher return intervals (e.g. limited water abstraction for irrigation or other uses).

B

Presence of dams (watershed area > 5% of the reach drainage area) with reduction of peak discharges, or spillways or retention basins functioning only for infrequent discharges (RI > 10 years). Or release of increased low flows downstream dams during the dry seasons of Mediterranean regime-dominated rivers, producing evident effects on vegetation and channel morphology.

C

Presence of dams (watershed area > 5% of the reach drainage area) with reduction of peak discharges, or spillways or retention basins functioning for relatively frequent discharges (RI ≤ 10 years), or existence of diversions of medium – large size with water restitution downstream of the reach, or diversions that induce a significant effect on channel-forming discharge.

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ILLUSTRATEDGUIDE

1

2

FigureA3.36Alterationofflows.Typicalalterationstructures.(1)Dam;(2)spillway.

FigureA3.37Rangeofchannel-formingdischarges.(includingthedischargeswithreturnintervalofupto10years).Q1.5(dischargewithareturnintervalof1.5years)isthevalueconventionallyassumedasthemostrepresentativeofchannel-formingdischarges.

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FigureA3.38Upstreamalterationofflows.Class A: negligible alteration; Class B: alteration of high discharges (with RI > 10 years) but not of channel-formingdischarges;ClassC:alterationofchannel-formingdischarges.

A3.4.1.2 A1H: Upstream alteration of flows without potentially relevant effects onchannelmorphology

DESCRIPTION

Thisindicatorevaluatespossiblealterationsoflowflowsnothavingsignificanteffectsonchannelmorphology(i.e.,theymaycausesomechangeintheextentofgeomorphicunits,butnotinthebankfullchannelsize).

The indicatorconsidersthealterationofflowoccurringupstreamofthereach. Infacts,generally, significantwaterwithdrawalsareput inplacebymeansofhydraulicstructures,whichalterthecontinuityofwaterandsedimentandarethereforeconsideredasbreakingpoints for the segmentation into reaches. In the case of water withdrawal with minorstructures/managementpractices insidethereach,whicharenotconsideredasarelevantdiscontinuityforsegmentation,theirpresenceisanywayaccountedforbythisindicator,asdescribedbelow.

Asforthepreviousindicator,twoprocedurescanbeconsidered,asfollows.

CLASS A CLASS B

CLASS C

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1.Dataavailable

The alterations of the overall hydrological regime are generally assessed by specificindices (e.g. IAHRIS, IARI, QM-HIDRI, etc.), which generally provide a measure of thedeviationbetweentheobservedhydrologicalregimeandthenaturalregimeintheabsenceofhumanintervention.Forexample,theindexIARIisobtained,dependingonavailableriverdischargedataqualityandconsistency,bycomparingthedailyand/ormonthlydischargesactuallyflowingthroughthecrosssectionandthecorrespondingnaturaldischarges.Whenasufficientlylongtimeseriesofflowdataisavailable,theuseofaspecificindex(suchastheIARI) is strongly advised, and the integration of morphological and hydrological aspectsallows for a complete definition and classification of stream hydromorphology. Wherehydropeaking is present (e.g. water storage hydropower plants), if hourly discharges areavailable,thealterationbyhydropeakingcanbeassessedbyusingproceduressuchasthatproposedbyCarollietal.(2015).

2.Datanotavailable

Inmostcases, sufficientdata toapply specific indicesofhydrological regimealterationare not available. However, for an overall hydromorphological assessment, a series ofinterventions and management practices have obvious and relevant effects on flowconditions.Similarlytotheprevioussub-indexA1M,asimplifiedprocedureisadopted,thatisbasedona criterionofpresence/absenceof specific typesofpressurecausingobvious,relevantlowflowalterations(e.g.abstractionforhydropower),describedasfollows.

EXTENDEDANSWERS

Confinement type All types

A Absence of any type of structure altering flow discharges (dams or other abstractions for irrigation, hydropower, drinking water) in the drainage catchment upstream or within the reach

B Presence in the drainage catchment upstream (or within the reach) of one or more structures altering flow discharges (dams or other abstractions for irrigation, hydropower, drinking water) that do not meet the criteria for class C

C

The reach, or a portion of it, is located between an abstraction and a restitution section of a hydropower plant (by-passed or depleted reach) and/or the reach is located immediately downstream of a hydropower reservoir. In presence of a water storage hydropower plant, if data are absent, it is assumed that the reach is significantly altered by hydropeaking.

Scores (note that C has a higher weigth compared to PC-U because of the lower number of indicators used for C streams for the calculation of the HMQI)

C PC-U A 0 0 B 8 11 C 16 22

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TableA3.4FlowchartforindicatorA1H.

A3.4.2 A2:Upstreamalterationofsedimentdischarges

DESCRIPTION

Anindirectevaluationofthealterationsinsedimenttransportisobtainedbasedontheexistenceinthecatchmentofblockingstructuresthatinterceptbedload(dams,checkdams,weirs), accounting for their drainage area in relation to the reach drainage area. Theindicatordoesnotconsiderhillslopeinterventions(e.g.reforestation,landslidestabilisation,etc.).Majorblockingstructures, suchasdams,areevaluatedhereonly for theireffectonsediment trapping (impacts on flow regime are considered in A1). Interception of thebedloadandriverfragmentationmayhavesignificanteffectsonthereach’smorphologicaldynamics.Thismaycauseareductionofdepositionalfeatures(e.g.bars), inducingerosionprocessesandeventuallypromotingunstableconditions.

Spatial scale Longitudinal: Upstream river network Lateral: Channel Measurements: Map layer of interventions, remote sensing

Thedegreeofalterationinsedimentdischargesisevaluatedasafunctionoftwoaspects:(1) the type of structure and its impact on bedload (i.e. full interception or partialinterception, depending on sediment filling); (2) the ratio between the drainage areaupstreamof the structures and the drainage area of thewatershed at the sectionof thereachclosure.

Concerningthetypeofstructures,thefollowingthreecasesareconsidered:(T1)Dams.Theycreateacompleteandpermanent(inafutureperspective)interceptionandtrappingofbedload(exceptinthecasesofmeasurementsofsedimentreleasedownstream,whichareaccountedfor).(T2)Structureswithtotalinterceptionofbedload.Thesedetermine(ordetermined)acompleteinterception(e.g.checkdamsofasignificantsizenotfilledbysediment),buttheir

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impactisconsideredtobelowerthandams,becauseoftheirtemporaryeffect(untiltheyarefilled).

Inmountain areas, category T2 generally includes check dams with total sedimentretention(retentioncheckdams:usuallyoflargedimensions).Usuallythesestructuresarecharacterizedbyasmallreservoirimmediatelyupstream.Includedinthiscategoryarealsoabstractionweirsofrelevantsize (in theorderofseveralmeters),whicharenotcurrentlyfilledwithsediment,andwhichhavetheeffectofatemporarycompleteinterception(untilfilling)ofbedload.

Inhilly–lowlandareas,categoryT2generallyincludesconsolidationcheckdamsorabstractionweirsofrelevantsize(intheorderofseveralmeters),whicharenotfilled,andwhichhavetheeffectoftemporarycompleteinterception(untilfilling)ofbedload.(T3)Structureswithpartialornointerceptionofbedload.Thesearesmallersizedstructures,oftenwiththepurposeofbedstabilizationratherthansedimentretention,oralsobiggerstructures(checkdams)withthepurposeofsedimentretentionbutnowcompletelyfilledbysediment.Inmountainareas,structuresofthecategoryT3canbegenerallyidentifiedwithfilledretentioncheckdams,opencheckdams,andconsolidationcheckdams.Thelatterareconsideredonlywhentheyformalongsequence,determiningthestabilizationofthelongitudinalbedprofile.Thedrainagearearelatestothecheckdamfurthestdownstream.Therefore,isolatedconsolidationcheckdamsthatareunabletosignificantlyreducetheupstreamsedimentsupplyarenotconsidered.Inhilly–lowlandareas,categoryT3generallyincludesconsolidationcheckdamsorabstractionweirs,butofasmallersize,orofalargersizebutfilledwithsediment.

The indicatordoesnot intend toevaluatealteration in theexactamountof thesedimentdischarge entering into a reach, but rather to assesswhether a significant change of thepotential sediment supply from the upstream area may have occurred. Concerning thedrainage area upstreamof the structures as opposed to that upstreamof the reach, thefollowingclassesareconsidered:(I)As≤5%Ar,thatistheareaupstreamthefromstructures(As)issmallerthan5%oftheareaupstreamofthereach(Ar)(e.g.adamupstreamwithadrainageareaof40km2comparedtoadrainageareaofthereachof500km2);(II)5%Ar<As≤33%Ar,thatistheareaupstreamfromthestructures(As)isbetween5%and33%oftheareaupstreamthereach(Ar)(e.g.adamupstreamwithadrainageareaof40km2comparedtothereach’sdrainageareaof400km2);(III)33%Ar<As≤66%Ar,thatistheareaupstreamfromthestructures(As)isbetween33%and66%oftheareaupstreamofthereach(Ar)(e.g.adamupstreamwithadrainageareaof120km2comparedtothereach’sdrainageareaof200km2);(IV)As>66%Ar,thatistheareaupstreamfromthestructures(As)is>66%oftheareaupstreamfromthereach(Ar)(e.g.adamupstreamwithadrainageareaof150km2comparedtothereach’sdrainageareaof200km2);(V)Thestructureislocatedattheupstreamlimitofthereach.

AssignationtothealterationclassasafunctionoftypologyanddrainageareasisreportedinTable4.

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TableA3.5DefinitionofclassesforindicatorA2.

As/Ar Type 5÷33% 33÷66% > 66% Upstream

l imit

(T1) Dams B1 B2 C1 C2

(T2) Check dams with total sediment retention or abstraction weirs ( large) with complete interception

A B1 B2 B2

(T3)

Fi l led or open check dams or sequence of consolidation check dams or abstraction weirs with part ial or no interception (or small in size)

A A B1 B1

MeasuresofsedimentreleaseorremovalIn the case of measures of sediment release downstream from a dam (or other

structure), the score is reduced according to the following rules (in any physiographiccontext):(1) Measures allowing for the flux of all bedload downstream (complete by-pass): two

classeslowerareassigned(e.g.fromC2toB2,orfromB1toA).(2) Measures allowing for ahigh but not total bedload flux downstream: a class lower is

assigned(e.g.fromC2toC1).Vice versa, if the maintenance agency in charge of a structure carries out a periodicsedimentremovalupstreamfromacheckdam(thatisnotreleaseddownstream)inorderto prevent it from filling completely, the structure is considered as causing a completeinterceptionofbedload(T2).Todeterminethefinalclassforthisindicator,thefollowingrulesneedtobeconsidered:1. The indicator is not applied for the most upstream reach of a river, unless relevantstructures of sediment interception (e.g. sequences of check dams) are located furtherupstream.2.Inthecaseofmorethanonestructureintheupstreamcatchment,thestructurewiththehighestscoreisconsidered.3.Inthecaseofanaturalbarrageanditsresultinglake(e.g.landslidedams,etc.),upstreamartificial interception structures are not considered in the evaluation of reachesdownstreamfromthelake.Identificationofexistingstructurescanbecarriedoutusingthemaplayerofinterventions(whenavailable)andremotesensing.NotethatthistypeofinformationconcerningexistingcrossingstructuresatthecatchmentscaleisanessentialpartofPhase1(generalsetting).Information on the degree of structure filling, should it be necessary to discriminatebetween two classes, can also be acquired from a map layer of interventions, frommanagement agencies, or directly from field surveys. In general, it is recommended toproceed by moving progressively upstream, and starting from the structures with thehighestscore,inordertoacquiretheinformationstrictlynecessaryforthedeterminationofthefinalscore.ThelogicalschemeisillustratedinFigure39.

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TableA3.6FlowchartoftheindicatorA2.(st=sedimenttransport).

Dam at the upstream limit? A2 in C2

Yes

No

Dam area >66%? A2 in C1 Yes

No

Dam area 33-66%? A2 in B2 Yes

No

Check dam/weir st=0 ups.limit or area >66%?

A2 in B2 Yes

No

Check dam/weir st=0 area >33% or

consolidation check dam/weir with no

interception >66%?

A2 in B1 Yes

No

Dam area 5-33%? A2 in B1 Yes

No

A2 in A

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EXTENDEDANSWERS

Confinement type All types

A

Absence of structures that can alter the normal flux of sediment along the hydrographic network, or presence of weirs and/or dams but with no significant effects. Dams (T1) are considered as not significant when As ≤ 5% Ar, i.e. the area upstream from the structures (As) is lower than 5% of the area upstream from the reach (Ar). Interception structures (T2) are considered as not significant when As ≤ 33% Ar. Structures with partial or no interception of bedload are considered as not significant when As ≤ 66% Ar.

B1

Presence of a dam (T1) for 5% Ar < As ≤ 33% Ar. One or more structures with total bedload interception (T2) for 33% Ar < As ≤ 66% Ar, or one or more structures with partial or no interception of bedload (T3) for As > 66% Ar.

B2 Presence of a dam (T1) for 33% Ar < As ≤ 66% Ar. One or more structures with total bedload interception (T2) for As > 66% Ar or at the upstream reach limit.

C1 Presence of a dam (T1) for As > 66% Ar. C2 Presence of a dam (T1) at the upstream reach limit. Measures of sediment release downstream: in case of measures allowing for the flux of all bedload downstream (complete by-pass), the structure is assigned to two classes lower. In case of measures allowing for a high but not total bedload flux downstream, the structure is assigned to one class lower.

ILLUSTRATEDGUIDE

3.1.1.1 Structuresinmountainareas

1

2

3

4

FigureA3.39Transversalstructuresofalterationofsedimentdischargesinmountainareas.(1)Dam;(2)retentioncheckdam;(3)opencheckdam;(4)sequenceofsteppedconsolidationcheckdams.

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Structuresinhilly–lowlandareas

1

2

3

4

FigureA3.40Transversalstructuresofalterationofsedimentdischargesinhillyandlowlandareas.(1)Consolidationcheckdam;(2)abstractionweir;(3)notfilledabstractionweir;(4)filledabstractionweir.

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ClassA

ClassB1

ClassB2

FigureA3.41Upstreamalterationofsedimentdischarges(1).ClassA:dam(T1)withanegligibledrainagearea(≤5%oftheareaupstreamfromthereach,Ar)(left);thetotalareaofportionsofthewatershedwithcheckdams(T2)is≤33%oftheareaupstreamfromthereach(right).ClassB1:dam(T1)withadrainageareabetween5%and33%oftheareaupstreamfromthereach(left);thetotalareaof portions of thewatershedwith checkdamswith complete interception (T2) is between33%and66%of the areaupstreamfromthereach(right).ClassB2:dam(T1)withadrainageareabetween33%and66%oftheareaupstreamfromthereach(left);thetotalareaofportionsofthewatershedwithcheckdamswithcompleteinterception(T2)is>66%oftheareaupstreamfromthereach.

Ar : area upstream the reach

Area upstream the structure (dam)

As �5% Ar

As2

As1

Area upstream the structures (check dams)

As (=As1+As2)��33% Ar

Ar : area upstream the reach

Area upstream the structure (dam)

5% Ar<As�33% Ar

Ar : area upstream the reach

area upstream the structures (check dams) with complete

interception 33% Ar<As�66% Ar

Ar : area upstream the reach

Area upstream the structure (dam)

33% Ar<As�66% Ar

Ar : area upstream the reach

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ClassC1 ClassC2

FigureA3.39Upstreamalterationofsedimentdischarges(2).ClassC1:dam(T1)withadrainagearea>66%oftheareaupstreamfromthereach(left).ClassC2:dam(T1)attheupstreamlimitofthereach(right).

Alterationoflongitudinalcontinuityinthereach

A3.4.3 A3:Alterationofflowsinthereach

DESCRIPTION

ThisisevaluatedinthesamewayasA1,butinthiscaseitreferstointerventionsalongthe reach. Interventions include spillways, flow diversions or water abstractions, andretentionbasins.Damsareexcludedbecausetheyarenecessarilyidentifiedwiththelimitofreach,thereforetheireffectsintermsofalterationofdischargearenecessarilyevaluatedinthe reach downstream. Alteration of flows below channel forming discharge caused bydamsarethereforenotconsidered inthis indicator.Notethatotherstructurestoo,whichhave a strong discontinuity impact on water discharge should be defined as the limitsbetweentworeaches(seeStep4:otherdiscontinuitiesduringthesegmentation),thereforeA3israrelyappliedtothistypeofstructure.

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) Measurements: Map layer of interventions, remote sensing

Identificationof existing structures canbe carriedoutby remote sensing,whereas theinformation required to assign a reach to a class should be obtained by a map layer ofinterventions, or directly by the agencies in charge of the structure’s management,indicating location, typeandoperationalmethods.All theconsiderationsmade forA1areappliedtothis indicator, includingthetwoprocedures(dataavailableornotavailable),asfollows.

Area upstream the structure (dam)

As>66% Ar

Ar : area upstream the reach

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1.Dataavailable

EXTENDEDANSWERS

Confinement type All types

A

Absence of interventions altering water discharges (spillways, diversions, retention basin, etc.) or interventions but with no significant effects (induced changes ≤ 10%) on channel-forming discharges (return interval RI from 1.5 to 10 years) and on discharges with RI > 10 years. This latter case is accounted for in A1H.

B Presence of interventions (spillways, diversions, retention basin, etc.) having significant effects (induced changes > 10%) on discharges with RI > 10 years, but with no significant effects (≤ 10%) on channel-forming discharges.

C Presence of interventions (spillways, diversions, retention basin, etc.) having significant effects (induced changes > 10%) on channel-forming discharge.

2.Datanotavailable

EXTENDEDANSWERS

Confinement type All types

A Absence of interventions altering water discharges or existence of interventions, but with no effects on channel-forming discharges and discharges with higher return intervals (e.g. limited water abstraction for irrigation or other uses).

B Presence of spillways, diversions or retention basins functioning only for infrequent discharges (RI > 10 years).

C

Presence of spillways, diversions or retention basins functioning also for relatively frequent discharges (RI ≤ 10 years), or existence of diversions of medium – big size with water restitution downstream the reach, or diversions such to induce a significant effect on channel-forming discharge.

ILLUSTRATEDGUIDE

1

2

FigureA3.42Otherstructuresthatcancauseanalterationofflowswithinareach.(BesidesthosedefinedforA1)(1)Retentionbasins;(2)dischargeabstraction.

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ClassA ClassB ClassC

NOALTERATION SPILLWAYWORKINGONLYFORPEAK

DISCHARGESWITHRI>15YEARSANDCAUSINGREDUCTIONINQOFABOUT50M3/S

RETENTIONBASINWORKINGFORALLPEAKDISCHARGES(RI>1YEAR)ANDCAUSINGAREDUCTIONINQOFABOUT15M3/S

FigureA3.43Alterationofflowsinthereach.ClassA:absenceofalteration.ClassB:alterationofdischargeswithRI>10years.ClassC:alterationofchannel-formingdischarges.

A3.4.4 A4:Alterationofsedimentdischargeinthereach

DESCRIPTION

Thisindicatorisbasedonthetypologyandfrequencyofblockingstructuresinterceptingbedloadalongthereach(checkdams,weirs,diversionstructures,etc.)orotherstructurescausing its alteration (e.g. retention basins, dam downstream, bed consolidation) byproducingapartial sediment trappingorbedload reduction inducedbyadecrease inbedslope. The indicator does not refer to hillslope interventions (e.g. reforestation, landslidestabilisation,etc.).

Spatial scale Longitudinal: Reach Lateral: Channel Measurements: Map layer of interventions, Remote sensing, Field survey

In the case of a dam located at the downstream limit of the reach, as previouslyexplained, itseffects in termsofbedload interceptionsareconsidered in thedownstreamreach(indicatorsA2andF1).However,thedamalsoaltersthenormalbedloadfluxfortheportion of the reach immediately upstream from the structure by decreasing the flowvelocity and inducing sedimentation. If the artificial reservoir created by the dam is of arelevant size, itwillnotbe subject to theassessmentprocedure (because the streamwillhave completely changed its original characteristics) (Figure45). Relevant size is normallyintended tobeequivalent to the spatial scaleofa site (i.e. single-threadchannels: lengthnotlessthan10timesthechannelwidth;multi-thread,widechannels:minimumlengthtotheorderof500m).Forreservoirsofasmallersize,theseare includedwithinthestreamreach(Figure45).

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FigureA3.44Ruleofevaluationoftheeffectsofadam/reservoiratthedownstreamlimitofthereach.

Retention check dams are high structures (up to 10m) aiming to trap sediment andwood,commonlyoccurring inmountainareas.Checkdams interceptall thematerialuntilthey are completely filled. In this case, and in the absence of sediment removal, anequilibriumbed profilewith a decreased bed slope tends to be reached, inducing coarsesediment deposition. Note that a check dam is usually associated with the boundarybetweentworeaches,exceptinthecaseofasequenceofclosecheckdamswhichmaybeincludedinthesamereachtoavoidexcessiveriversegmentation.Inrecentdecades,opencheckdamshavebeenincreasinglyused,allowingthetransportdownstreamofbedloadofsmallergrainsize.

For the large structures described so far, definition of classes is simply based on thepresence/absence of one (or more) of these structures along a reach, and not on theirnumber or frequency (i.e. the presence of one structure along a reach of any length issufficientfortheassignationofthereachtoagivenclass).

Consolidation check dams are not designed to intercept sediment and wood, but todecrease the intensity of the bedload transport and the effect of erosion through areduction inbedslope. In thiscase,several structuresarepositionedalongagivenreach.Theeffectofthesestructuresonchannelmorphologydependsonthecombinationoftheirdistanceandheight (i.e. thedifference inelevationbetween structures) compared to thetotaldifferenceinelevationwithinthereach.However,theinformationonstructureheightisdifficulttoobtain,thereforetheindicatoronlyreferstothedensityofstructuresalongareach(i.e.numberperreachkm),butdifferentiatesthedegreeofalterationdependingonbedslope.Atransversestructureinasteepchannelgenerallyproducesasmallerupstreameffect compared toa channelwitha relatively low slope,where theeffectmayoccur forlongdistancesupstream(hundredsofmeters).

Finally, instream retention basins and abstractionweirs, which can partially interceptthe sediment transport, are also considered in this indicator (note that in the case ofchannels with bed slope S>1%, retention basins are considered as open check dams,whereas in channels with bed slope S≤1% they are counted together with consolidationcheckdamsandweirs).

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Allthestructurescaneasilybeidentifiedbyremotesensing,exceptinthecaseofsmallandconfinedchannels(whereveryhighresolutionaerialphotosarenotavailable).Inthesecases,amaplayerofinterventionsand/orfieldsurveyarerequired.

EXTENDEDANSWERS

Confinement type All types

A

Absence of any type of structures altering sediment discharges: there are no structures in the reach aimed to intercept sediment and wood (check dams, abstraction weirs, etc.) or which cause an alteration of sediment discharges (retention basins, dam downstream) although not designed for this purpose.

B

Steep channels (bed slope S>1%): consolidation check dams/weirs with relatively low density (≤ 1 every 200 m on average in the reach) and/or one or more open check dams (including instream retention basins). Channels with bed slope S≤1%: consolidation check dam and/or abstraction weirs (including instream retention basins) with relatively low density (≤ 1 every 1000 m on average in the reach). In the case of presence of anabranches, the length of the reach is the sum of the lengths of the anabranches.

C

Steep channels (S>1%): consolidation check dams/weirs with high density (>1 every 200 m on average in the reach) and/or one or more retention check dams. Channels with S≤1%: consolidation check dams and/or abstraction weirs (including instream retention basins) with high density (>1 every 1000 m on average in the reach) Or presence of a dam and/or artificial reservoir at the downstream reach limit (any physiographic context).

Additional scores Where transversal structures, including bed sills and ramps (see A9) are > 1 every 150 m in steep channels (S>1%), or >1 every 750 m in channels with S≤ 1%, add 6. Where transversal structures, including bed sills and ramps (see A9) are > 1 every 100 m in steep channels (S>1%), or >1 every 500 m in channels with S≤ 1%, add 12.

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ILLUSTRATEDGUIDE

ClassA ClassB

ClassC

FigureA3.45Alterationofsedimenttransport.ClassA:absenceofalteration.ClassBinsteepchannels(bedslopeS>1%):consolidationcheckdamsinlimitednumber(≤1every200m);oroneormoreopencheckdams.ClassBinchannelswithbedslopeS≤1%:consolidationcheckdamsor abstractionweirs in limitednumber (≤ 1 every1000m).ClassC in in steep channels (bed slopeS > 1%): frequentconsolidationcheckdams(>1every200m)oroneormoreretentioncheckdams.ClassCinchannelswithbedslopeS≤1%:frequentconsolidationcheckdamsand/orabstractionweirs(>1every1000m).

1

2

FigureA3.46Caseswithveryhighdensityoftransversalstructures:Anadditionalscoreof6or12(dependingonthedensity)isapplied.

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A3.4.5 A5:Crossingstructures

DESCRIPTION

This accounts for thepresenceand frequencyof crossing structures, includingbridges,fords, and culverts, which may reduce or intercept sediment and wood transport. Onlybridgeswhichinterferewiththefluvialcorridorareconsidered,i.e.thosebridgeswithsomeartificialelement(piersorabutments)inthechanneloradjacentplain,orwhichpotentiallyinterferewithwaterfluxesalthoughonlyduringexceptionalfloodevents.Bridgesthatarecompletelyunrelatedtothefluvialcorridorarenotcounted(e.g.aviaductcrossingavalleymarkedly higher than the channel and with piers and/or abutments standing directly onhillslopes).Regardingfords,onlythosewithfixedcrossingstructuresareaccountedforhere(i.e. dirt roads are not considered), because of their partial influence on bedload (coarsesediment).Finally,thecaseswherestreamscrossurbanareasundergroundareconsideredasculverts.Theyhaveeffectsonchannelcross-sectionsand lateralcontinuitysimilar toacrossingstructure,whiletheadditionalalterationsassociatedtoaculvert(fixedbanks,bedrevetments)areevaluatedseparatelythroughtheindicatorsA6andA9.

Spatial scale Longitudinal: Reach Lateral: Channel Measurements: Remote sensing, topographic maps, field survey

Allthesestructurescaneasilybeidentifiedbyremotesensing,exceptforculverts,whichmayrequiremoredetailedanalysisusingtopographicmapsand/orfieldchecks.Asforotherindicatorsofartificialelements,this indicatorevaluatesthenumberofcrossingstructuresalongareachratherthantheireffect.

EXTENDEDANSWERS

Confinement type All types A Absence of crossing structures (bridges, fords, culverts).

B

Presence of some crossing structures (≤ 1 every 1000 m on average in the reach). In the case of presence of anabranches, the reach length is the sum of the lengths of the anabranches.

C Presence of many crossing structures (> 1 every 1000 m on average in the reach).

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ILLUSTRATEDGUIDE

1

2

3

4

FigureA3.47Crossingstructures.(1) Bridgewith interferenceon fluvial dynamics; (2) crossing structureunrelated to the fluvial corridor; (3) fordwithculverts;(4)culvert.

ClassA ClassB ClassC 1

2

3

FigureA3.48Crossingstructures.Class A: absence of structures. Class B: crossing structures in limited number (≤1 every 1000 m). Class C: frequentcrossing structures (>1 every 1000 m). On the right: interference of bridges with the fluvial corridor. (1) Bridgecompletelyunrelated(viaductcrossingavalleyatrelevantheight);(2)bridgewithnopiersbutwhichmayinterferewithhighdischarges;(3)bridgeveryhighbutwithpiersinterferingwithfluvialdynamicsprocesses.

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Alterationoflateralcontinuity

A3.4.6 A6:Bankprotections

DESCRIPTION

Varioustypesofbankprotectionareconsideredwhichalterthesupplyofsedimentandwoodfromlateralchannelmobility,includingbothhardbankreinforcement(walls,rip-rapsgabions,groynes),andsoftreinforcement(bioengineering).

Spatial scale Longitudinal: Reach Lateral: Banks Measurements: Map layer of interventions, remote sensing, field survey

Onlybankprotectionsalongthebanklines(whicharethelimitsofthebankfullchannel)orintheclosesurroundingsareconsidered:bankprotectionsbuiltinpastperiods,whichatpresent far from the channel and therefore having no immediate effects on channelmobilityarenotassessed(theymaybeconsideredintheindicatorF5,havingtheeffectoflimitingtheerodiblecorridor).

Analysis from remote sensing does not always allow the identification of this type ofstructure, especially when they have been built in the past and are partly covered byriparian vegetation. The integration of remote observations with the map layer ofinterventionsand/orfieldchecksisrecommended.

Theindicatorisbasedonthepercentageofprotectedbanksoverthetotallength(sumof both banks),where the latter is defined in aGIS (for simplicity, itmay be assumed tocorrespondtotwicethereachlengthmeasuredalongthecentreline).Whereanabranchesarepresent,thetotalbanklengthisthesumofbothbanksforeachanabranch.

Aparticularcaseisthatofgroynes,becausetheyareplacedperpendiculartothebank.Similarlytothepreviousrule,onlygroynesincontactorwithinthechannelareconsidered(externalgroynesareconsidered inthe indicatorF5)andanevaluationofthegreatersizebetween the groyne width and the protruding length is obtained (generally from aerialphotos, and eventually from field check). In the case of groynes with the outer limitcorrespondingtothebankedge,theirprotrudinglengthisequaltozeroandthereforetheyhave no effects for this indicator. Note that the indicator only evaluates the presence ofgroynes in terms of protected bank length, and not in terms of the magnitude of theireffects(e.g.distanceofinfluence).

EXTENDEDANSWERS

Confinement type All types

A Absence or localized presence of bank protections, i.e. for a length ≤ 5% total length of the banks (sum of both banks). In the case of presence of anabranches, the total bank length is the sum of both bank lengths for each anabranch.

B Presence of protections for ≤ 33% total length of the banks (sum of both banks). C Presence of protections for > 33% total length of the banks (sum of both banks). Additional scores For a high density of bank protections (>50% of total length of the banks), add 6. For an extremely high density of bank protections (>80% of total length of the banks), add 12.

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ILLUSTRATEDGUIDE

1

2

3

4

5

FigureA3.49Bankprotectionstypes.(1)Bankwalls(2)groyne;(3)ripraps;(4)gabions;(5)bioengineeringbankstabilization.

ClassA ClassB ClassC

FigureA3.50Bankprotections:classification.ClassA:localizedprotections(redlines);intheexamplethestructuresare4%ofthetotallengthofthetwobanks.ClassB:significantpresenceofbankprotections(≤33%); intheexampletheyareabout30%ofthetotal lengthofthetwobanks.ClassC:relevantpresenceofbankprotections(>33%);intheexampletheyoccupyabout50%ofthetotallengthofthetwobanks.

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1

2

FigureA3.51Caseofgroynes.(1)Groynesoutsideofthechannelarenotconsidered(instead,theyareaccountedforintheindicatorF5);inthecaseofstraightgroynesincontactwiththechannelboundary,thewidthofthegroyneheadisusuallynegligible.(2)Inthecaseofgroynesenteringinthechannel,thegreatersizebetweenprotrudinglengthandheadwidthisconsidered(thelatteris generally theprevailing size in the caseof hammerhead groynes).Note thathammerhead groynes in contact (asopposedtostraightorbayonetgroynes)areconsidered.

A3.4.7 A7:Artificiallevées

DESCRIPTION

This indicator accounts for the presence and position of artificial levées (orembankments). They have an effect on the lateral hydrological continuity impeding thenatural floodingof areas adjacent to the river. It is basedon their longitudinal continuityanddistancefromthechannel.Bankprotectionsorembankments(evaluatedinA6)withaheight greater than the floodplain level arealsoevaluatedby this indicator, aswell as allthose artificial infrastructures (e.g. roads) which also functions as a levée. On the otherhand,artificiallevéeswhichalsofunctionasbankprotectionarealsoaccountedforbytheindicatorA6.

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) Measurements: Remote sensing, topographic maps, field survey, map layer of interventions

The indicator is applied only to partly confined and unconfined channels, becauseartificial levéesaretypicallypresentinthefloodplain(artificial levéesinconfinedchannelsareinfrequentandhavenosignificanteffectonthehydrologicallateralcontinuity).

Thisindicatorismainlyevaluatedbyremotesensing,supportedbytopographicmaps.Inthecaseofbankprotectionswhichfunctionaslevées,integratingtheevaluationwithafieldsurveyand/orbyconsultingthemaplayerofinterventionsisrecommended.

Regardingthelength,thepercentageoftheartificiallevée’slengthoverthetotallengthof the banks is considered (similarly to the previous indicator) though, in this case, thelengthofbanksdirectlyincontactwithhillslopesisexcluded.Regardingthedistance,threepossible cases are considered: (1) “set-back levées”:where set back distance > themeanchannelwidth(W);(2)“close”:wheredistance≤W;(3)“bank-edgelevées”:whentheyareimmediately in contactwith the top of the bank, or at amaximumdistance of the sameorderofmagnitudeasthebankheight.Thedistancehereisconsideredtoaccountforthe

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effectsoflevéesonlateralchannelmobilityandonhabitatdiversity,ratherthanintermsofhydraulicrisk.SelectionoftheclassismadeaccordingtotheextendedanswersandTable5.Notethatthecalculationismadeseparatelyforthetworiversides:e.g.inthecaseofaleftbankwith100%incontactandarightbankwith20%incontactand80%close,thetotalinthereachwillbe60%incontactand40%close.

Inthecaseoftwoartificiallevéesystems,thedistancereferstothelevéesclosesttothechannel. In the case ofanabranching channelswithmultiple artificial levée systems (e.g.oneforeachindividualanabranch),thethreecasesmustbeappliedtoeachanabranchandthetotalbanklengthisthesumofbothbanksforallanabranches.TableA3.7Definitionofclassesasafunctionofthelengthofbank-edgeandcloselevées(in%overthetotallengthofbothbanks).

Class Sum of bank-edge and close [%]

Bank-edge [%]

A 0÷5 0÷5

B 5÷90 0÷50 90÷100 0÷33

C 50÷90 50÷90 90÷100 33÷100

EXTENDEDANSWERS

Confinement type Partly confined or unconfined

A

Absent or set-back levées (i.e. distance > W) for any length, or localized presence of close and bank-edge levées (≤5% of the total length of the banks). In the case of presence of anabranches, each anabranch must be evaluated and the total bank length is the length of both banks for all anabranches.

B

The sum of close and bank-edge levées is > 5% of the total length of the banks, including the following cases (excluding banks directly in contact with hillslopes): (a) sum of close levées and bank-edge levées ≤ 90% of which bank-edge levées ≤ 50%; (b) sum of close levées and bank-edge levées > 90% of which bank-edge levées ≤ 33%.

C

The sum of close and bank-edge levées is > 50% of the total length of the banks, including the following cases (excluding banks directly in contact with hillslopes): (a) sum of close levées and bank-edge levées ≤ 90% of which bank-edge levées > 50% and ≤ 90%; (b) sum of close levées and bank-edge levées > 90% of which bank-edge levées > 33%.

Additional scores In the case of artificial bank-edge levées > 66% add 6. In the case of artificial bank-edge levées along > 80% of total length of the banks) add 12.

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ILLUSTRATEDGUIDE

1

2

3

FigureA3.52Artificiallevées.(1)Earthenlevees;(2)bank-edgelevee;(3)bankwallswithfunctionoflevees.h

ClassA ClassB

ClassC Set-back

Close

Bank-edge

FigureA3.53Artificiallevees.ClassA:localizedbank-edgeorcloselevees(≤5%).ClassB:thetotalsumofbank-edgeandcloseleveesis≤90%,withbank-edgearebetween33%and50%(left),orthetotalsumofbank-edgeandcloseleveesis>90%butbank-edgeare≤33%(right).ClassC:bank-edgeleveesare>50%ofthereach(left),orbank-edgeleveesarebetween33%and50%butthetotalsumofbank-edgeandcloseleveesis>90%(right).Bottomright:definitionofset-back,closeandbank-edgelevees.

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1

2

FigureA3.54Casesofbank-edgelevéesoccurringformostofthereach.Inthiscase,anadditionalscoreof6or12(dependingonthe%ofthereachlength)isadded.

Alterationofchannelmorphologyand/orsubstrate

These indicators include other categories of artificial elements and interventions notconsidered by previous indicators, which have specific effects on channel morphologyand/oronbedsubstrate.Notethatalsootherstructuresincludedinpreviousindicatorsmayhave effects on channel morphology (e.g. bank protections may cause a reduction inchannelwidth,checkdamsmaycausethevariationofthebedconfigurationandsubstrate,etc.).

A3.4.8 A8:Artificialchangesoftherivercourse

DESCRIPTION

This indicator accounts for artificial past changes in the river course (recent or inhistoricalperiods).This indicatordoesnotrequireahistoricalresearchofartificialchannelchanges, which would be out of the scope of this evaluation, but only well known andrelevant changes should be considered (e.g.meander cutting, change of position of rivermouth, etc.). These kinds of artificial changes of the river course may have altered thenatural channel morphology and modified natural geomorphological and hydraulicprocesses,withresultinglossofphysicalhabitats.

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) Measurement: Historical sources and/or remote sensing

The indicator does not include artificialmodifications that affect only the channel sizeand not the planform (e.g. channel narrowing). Conversely, the indicator does includeoverall channelization interventions drastically modifying the planform pattern, such asdredging,straightening,orevendigginganewchannel(e.g.inareaswithwaterstagnationtopromotedrainage).Thesehistoricallandreclamationschemesbydrainage,carriedoutbyexcavatingnewchannelsorbydredgingexistingones,canbequitefrequentespeciallyinLow-Energysystemswherepartly(ortotally)artificialchannelsdonotnecessarilydisplaybank protections or artificial levées because of the low energy of the river and/or the

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continuous maintenance of such channels may prevent morphological changes andrecovery. For such cases, i.e. when an additional score for A6 and/or A7 is not alreadyapplied,anadditionalscoreforthis indicator isassigned(seethefollowingtable)becausethese historical artificial changes still have a large impact on the current morphologicalconditionsduetothelowrecoverycapacityofthesystem.

The indicator is mainly assessed using historical sources (available information abouthistorical changes). Remote sensing can provide a support by identifying abandonedchannelformsinthefloodplain(e.g.tracesofoldmeandersorrelictoxbowlakes,etc.),buthistoricalinformationisinanycaseneededtoassesswhethermorphologicalchangeswereduetohumaninterventions.

Theindicatorisappliedonlytopartlyconfinedandunconfinedchannels.Inthecaseofconfined channels, artificial changes in the river course are infrequent and usually onlyconcern limited portions of the channel. To determinewhether classesB orC should beassigned,theindicatorevaluatesthelengthofthereachaffectedbytheartificialchangeinrivercoursecomparedtothetotalreachlength.

EXTENDEDANSWERS

Confinement type Partly confined or unconfined

A Absence of artificial changes of river course in the past (meanders cut-off, channel diversions, etc.).

B

Presence of artificial changes of river course (meanders cut-off, channel diversions, etc.) in the past for ≤ 10% of the reach length. In the case of presence of anabranches, the length of the reach is the sum of all the lengths of single anabranches.

C Presence of artificial changes of river course (meanders cut-off, channel diversions, etc.) in the past for > 10% of the reach length.

Additional scores In the case of historical drainage and dredging works for > 50% of the reach, when an additional score for A6 and/or A7 is not already applied, add 6. In the case of historical drainage and dredging works for > 80% of the reach, when an additional score for A6 and/or A7 is not already applied, add 12.

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ILLUSTRATEDGUIDE

FigureA3.55Artificialchangesofrivercourse.Exampleofwell knownartificial changes (meander cut-offs, changeofpositionof rivermouth)occurring inhistoricaltimes.

FigureA3.56DrainageanddredgingworksinLow-Energy,fine-grainedstreams.

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ClassA ClassB ClassC

FigureA3.57Artificialchangesofrivercourse.ClassA:absenceofartificialchanges.ClassB:artificialchangesforalength≤10%ofthereach.ClassC:artificialchangesforalength>10%ofthereach.

A3.4.9 A9:Otherbedstabilizationstructures

DESCRIPTION

Thisindicatoraccountsforothercrossingstructureswhich,ingeneral,causeincreasesinthe rigidity of the bed, paving or reinforcement, but without significantly altering thesedimenttransport.Theseincludebedsillsandrampsbuilttoreducebedincision,ofteninassociation with bridges, and revetments of the channel bed, both impermeable andpermeable.Bedrevetmentscausestrongalterationinchannelmorphologyintermsofthedisappearanceofsedimentandrelatedbedforms(lossofhabitats)aswellasintermsofanalteration of vertical continuity with groundwater (hyporheic zone). These structures arecommon in steep mountain reaches (to prevent channel incision), but also along urbanreachesinpartlyconfinedandunconfinedchannels(topreventchannelsedimentation,e.g.onalluvialfans).

Theindicatoraccountsforbedstabilizationstructurefrequencyorpercentageandtype(permeable or impermeable), respectively, for sills/ramps (also taking into account thereachslope)andrevetments.

Spatial scale Longitudinal: Reach Lateral: Channel Measurements: Map layer of interventions, remote sensing, field survey

The evaluation is carried out by remote sensing, except for small confined channels,where these structures are not visible (except where very high resolution images areavailable). When the structures are not visible from remote sensing, the map layer ofinterventions and/or field survey is necessary, recording only the number of structures(additionalinformationontypology,characteristicsisnotrequired).

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EXTENDEDANSWERS

Confinement type All types A Absence of other bed stabilization structures (bed sills, ramps) and revetments.

B

Presence of bed sills and/or ramps with relatively low density, i.e. ≤ 1 every d on average along the reach, where d = 200 m for steep channels (bed slope S >1%) or d = 1000 m for bed slope S≤1%, and/or limited presence of revetments: bed revetments occupy a length ≤ 25% of the reach with permeable systems and/or ≤ 15% with impermeable systems. In the case of anabranches, the reach length is the sum of the lengths of anabranches.

C1 Presence of bed sills/ramps with a density of > 1 every d on average in the reach and/or significant presence of revetments: bed revetments occupy a length ≤ 50% of the reach with permeable systems and/or ≤ 33% with impermeable systems.

C2 Widespread presence of revetments: bed revetments occupy a length > 50% of the reach with permeable systems or > 33% with impermeable systems.

Additional scores For a high density of bed revetments, i.e. permeable revetments >80% of the reach length or impermeable revetments >50%, add 6. For an extremely high density of impermeable bed revetments (i.e. >80% of the reach length), add 12.

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassB

ClassC1

ClassC2

FigureA3.58Otherbedstabilizationstructuresandrevetments.ClassA:totalabsenceofotherbedstabilizationstructuresorrevetments.ClassB:presenceofsills(firstrowonright)ormassramps(secondrowonleft)withlowdensity.ClassC1:varioussillsandpartialbedrevetment.ClassC2:totalbedrevetmentwithimpermeablesystems.

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ClassA ClassB

ClassC1 ClassC2

SILL

PERMEABLEREVETMENT

MASSRAMP

IMPERMEABLEREVETMENT

FigureA3.59Otherbedstabilizationstructuresand/orrevetments.Class A: absence of bed stabilization structures and/or revetments. Class B: bed stabilization structures (sills, ramps)withadensity≤1everyd(d=200mforsteepchannels,d=1000mforbedslopeS≤1%),orpermeablerevetmentswithlength≤25%ofthereachand/orimpermeablerevetmentswithlength≤15%ofthereach.ClassC1::bedstabilizationstructures(sills,ramps)withadensity>1everyd,orpermeablerevetmentswitha length≤50%ofthereachand/orimpermeablerevetments≤33%ofthereach.ClassC2:permeablerevetments>50%ofthereachand/orimpermeablerevetments>33%ofthereach.

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Maintenanceandremovalinterventions

A3.4.10 A10:Sedimentremoval

DESCRIPTION

This indicator aims to provide an evaluation of the existence and relative intensity ofsediment removal. Such activity may induce several negative effects, in terms ofmorphological processes and evolution (bed incision) as well as impacting on the riverecosystem(Rinaldietal.,2005).

Spatial scale Longitudinal: Reach Lateral: Channel Measurements: Map layer of interventions, remote sensing, field survey

Sediment removal includes eithermining activity (excavationof gravel or sandpits forsediment exploitation) and interventions aimed at channel dredging and re-sectioning toreducefloodrisk(e.g.,channelloweringandwidening).Theindicatordoesnotaccountforlocal sediment removal, such as in the case of maintenance upstream from retentionbasin/checkdams(theseeffectsarealreadyaccountedforbyindicatorA4).

Theevaluation is slightlydifferentbetweenconfined andpartly confined -unconfinedchannels. Intheformercase,theinvestigatedtimeperiodisexclusivelythatofthelast20years (aswith the following two indicators). The difference between the three classes isdeterminedby theextensionofany removalactivity (absent, localized,widespread in thereach)duringthistimeperiod.Inthecaseofpartlyconfined-andunconfinedchannels,twotimeperiodsareconsidered:(a)recentactivity(thelast20years,asforconfinedchannels);(b)pastactivity,i.e.overthelast100years.The1950sisgenerallythedecadeofmaximumactivity inmany European countries (Rinaldi et al., 2005) but in other countries, intensesedimentdredgingmayhaveoccurred in the firsthalfof the20thcentury. Informationonrecent activity can be obtained from public agencies in charge of rivermanagement andmaintenance and/or from field evidence. Regarding past activity, the indicator intends toprovide a gross evaluation limited to the presence or absence of such activity, based onavailable information,sinceaquantificationofextractedvolumes isnotpossible.For this,twosituationsareconsidered:(1)absentornegligiblepastactivityofsedimentremoval;(2)past activity of sediment removal:when there is reliable information that the number ofminingsitesandtheextractedvolumesaresignificant(notnegligible).Indirectindicatorsofintense activitymaybe thenumberofmining sites at present or in thepast (fromaerialphotosof the1950s) in thevicinityof the river channel, intense incision (seeCA3) that isattributabletominingactivity,etc.

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EXTENDEDANSWERS

Confinement type Confined Range of application Not evaluated in the case of ERT type 1

A Evidence/reliable information of absent significant sediment removal activity during the last 20 years.

B Evidence/reliable information of significant but localized (only one site) sediment removal activity during the last 20 years.

C Evidence/reliable information of significant and widespread (more sites along the reach) sediment removal activity during the last 20 years.

Confinement type Partly confined or unconfined

A Absence of significant sediment removal activity either in the past (over the last 100 years) and during about the last 20 years.

B1 Sediment removal activity in the past (last 100 years) but absent during about the last 20 years.

B2 Sediment removal activity during the last 20 years but absent in the past (last 100 years). C Sediment removal activity in the past (last 100 years) and during the last 20 years.

ILLUSTRATEDGUIDE

1

2

3

4

FigureA3.60Sedimentremoval.(1)and(2)Recentandcurrentactivity;(3)and(4)indirectindicatorsofpastactivityarethepresenceofminingsites.Inthecaseofpartly-andunconfinedchannels,ClassB1,B2orCdependsontheoccurrenceofsedimentremoval inthepast(since1950’s)and/orinrecenttimes(last20years).

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A3.4.11 A11:Woodremoval

DESCRIPTION

Wood removal can periodically be carried out by various public agencies in charge ofriver management and maintenance, usually in conjunction with cutting vegetation (seenext indicator) and/or sediment removal. Typically, only larger sized woody material isremoved,whilesmallerwoodydebris(smalltrunks,branches)isleftinthechannel.

Wood removal is justifiable for safety reasons (e.g. to avoid creation ofwood jams atbridges during flood events), however has a significant impact on the fluvial system (e.g.reduction of hydrodynamic complexity, and therefore morphological and sedimentarydiversity,withthedisappearanceofphysicalhabitatsandorganicmaterial).

Spatial scale Longitudinal: Reach Lateral: Channel and floodplain Measurements: Information by public agencies

The indicator is not applied in areas of tundra in northern Europe, where woodyvegetation is naturally absent, as well as in reaches above the tree-line ( i.e. the samecriteriaofapplicabilityasF11).Foritsapplication,itisnecessarytoacquireinformationontotalorpartialwoodremoval(wherepartialindicatestheremovalofonlysomeverylargewoodpiecesorlocalisedremovalinspecificsites)duringthelast20years.Thistimeintervalis used both because of the availability of information from public agencies, and alsobecause of the natural capability of streams to partly re-establish a sufficient quantity ofwood from the banks, hillslopes and upstream reaches. Where reliable information islacking, theanswer isB.As for indicatorA10,wood removal from retentionbasins/checkdamsisnotconsidered.

EXTENDEDANSWERS

Confinement type All types

Range of appl ication Not evaluated above the tree-line and in streams with natural absence of riparian vegetation, such as in north-european tundra

A Absence of interventions for the removal of large wood (diameter > 10 cm and length > 1 m), at least in the last 20 years, or reliable information of removal of only negligible volumes.

B

Reliable information/evidence of partial removal (or cut into <1 m long pieces) interventions during the last 20 years, that is, the removal of some elements only, often following flood events. Here are also included the cases of permission for removal by private citizens, even without any intervention from public agencies..

C Reliable information/evidence of total removal (or cut into <1 m long pieces) interventions by public agencies during the last 20 years.

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassC

FigureA3.61Woodremoval.ClassA:absenceofinterventionsofwoodremoval.ClassB:partialremoval,includingremovalbyprivatecitizens.ClassC:totalremovalbypublicagencies.

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A3.4.12 A12:Vegetationmanagement

DESCRIPTION

Riparianwoodyvegetationinthefluvialcorridor(banks,floodplain,recentterraces)andin the channel (mature and pioneer islands) performs severalmorphological functions, inparticular providing wood material (from natural tree death, bank erosion, occasionaltopplingandbreakage,orfromhillslopeprocessesinconfinedchannels).Moreoverwoodyvegetationtrapssedimentandwoodmaterialduringfloods,contributingtothediversityofthe river habitat mosaic. Aquatic vegetation (either submerged and emerged) may alsohaveasignificant impactonriverhydraulics,andconsequentlyonsedimentaccumulationanderosion(e.g.Gurnelletal.,2006,GurnellandGrabowski,2016).

Similarlytothepreviousindicator,periodicinterventionsofvegetationcuttingbypublicagencies are motivated by safety reasons, but they have various impacts on themorphological and biological natural processes related to riparian vegetation. In order toreduce such impacts,public agenciesare recentlyoriented towardsselective cutting (e.g.involving only the oldest trees) rather than a total removal. The latter approach induceslowerimpactthantotalvegetationcuttingacrosslargeareas,howeverinrelationtoriparianvegetation,italtersthenaturalstructureoftheforest.Vegetationcuttingofriparianareasnot directly in contact with the channel (but included in the fluvial corridor) has lowermorphological and ecological impacts compared to intervention on channel banks. Notethatgrazingactivityisconsideredtobepartofvegetationcutting,asitpreventsvegetationgrowth.Aquaticvegetationisalsofrequentlyremovedorpartlyremovedbycuttingand/ordredgingforsafetyreasons.

Spatial scale

Longitudinal: Site/Reach Lateral: channel and portions of floodplain (partly confined - unconfined) adjacent to the banks, or adjacent plain / hillslopes (confined) for woody and shrub vegetation management; channel for aquatic macrophytes

Measurements: Information from public agencies and field site check (presence of butts)

TheindicatorisnotappliedintoareasoftundrainnorthernEurope,wherevegetationisnaturallyabsent.Foritsapplication,theoperatormustcollectinformationfromthepublicagencies responsible for vegetation management, and observe in the field any possibleevidenceofpastcuttings(i.e.presenceofrootwads,ordumpingofaquaticvegetationclosetothechannel).Theindicatorisappliedinthecaseofsignificantcuttingactivity(justafewplants cut along the reach are not considered) in the channel (i.e. on islands),within theareasexternaltothebanks(i.e.includingthemodernfloodplainandrecentterraces)andonhillslopes. For riparian vegetation, the investigated area corresponds to the width offunctionalvegetationidentifiedwiththeindicatorF12,assumedtobeatleastequaltonW,whereWisthechannellength,n=2forsingle-threadoranabranchingchannels,andn=1forbraidedandwanderingchannels; for confinedchannels,up to50metersonhillslopesand for each bank. For the same reasons as for the previous indicator, the time intervalconsideredincludesthelast20yearsinthecaseofriparianvegetation,whereasthelast5yearsareconsideredforaquaticvegetation.TheindicatorisnotappliedforthosereacheswhereF12andF13havenotbeenevaluated.

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Three cases of management of riparian vegetation are considered: (A) absence orselective cutting within the areas external to the banks; (B) selective cutting along thebanks,ortotalcuttingalongthebanksfor≤50%ofthereachlength,ortotalcuttingofanydistancewithintheareasexternaltothebanks;(C)totalcuttingalongthebanksfor>50%ofthereachlength.

TheevaluationofaquaticvegetationmanagementismainlyrelevantinthecaseofLow-Energy channel morphologies (i.e. ERT types 17-22) in which the investigated areacorrespondstothechannel.Insuchacase,thefollowingthreeclassesofaquaticvegetationmanagement are considered (similarly to indicator A11): (A) absence of cutting and/ordredging; (B) partial cutting and/or dredging; (C) total cutting and/or dredging. Theassessmentsforriparianandaquaticvegetationmanagementarethencombinedtoderiveacombinedclass(A,BorC)oftheindicatorA12accordingtothematrixshowninTable6.

TableA3.8DefinitionoftheclassesfortheindicatorA12whenmanagementofemergentaquaticmacrophytesoccurs.

Management of vegetation in the f luvial corr idor

A B C Management

of aquatic macrophytes

A (absence) A B C B (partial cutting and/or dredging)

B B C

C (total cutting and/or dredging)

B C C

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EXTENDEDANSWERS

Confinement type All typs

Range of application

Riparian vegetation management: Not evaluated above the tree-line and in streams with natural absence of riparian vegetation, such as in tundra areas

A

Vegetation not subject to cutting interventions along the banks, or only affected by selective cutting within the areas external to the banks (floodplain for partly confined - unconfined, hillslopes for confined) during the last 20 years and absence of cutting and/or dredging of the aquatic macrophytes along the reach during the last 5 years (case A).

B

- Vegetation subject to interventions of selective cutting along the banks for any distance, or total cutting for a length ≤ 50% of the reach; or total cuttings of any distance within the areas external to the banks (last 20 years), and absence of cutting and/or dredging or reliable information/evidence of partial cutting and/or dredging interventions by public agencies of the aquatic macrophytes during the last 5 years along the reach; Or - Management of vegetation in the river corridor as in case A, and reliable information/evidence of partial or total cutting and/or dredging interventions by public agencies of the aquatic macrophytes during the last 5 years along the reach. In the case of anabranches, the reach length is the sum of the lengths of the anabranches.

C

- Vegetation subject to total cutting along the banks for a distance > 50% of the reach during the last 20 years, and any case of management of aquatic macrophytes; Or - Management of vegetation in the river corridor as in case B, and reliable information/evidence of total cutting and/or dredging interventions by public agencies of the aquatic macrophytes during the last 5 years along the reach.

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassC

FigureA3.62Vegetationmanagement.ClassA:absenceofvegetationcuttinginterventions.ClassB:interventionsofselectivecutting.ClassC:interventionsoftotalvegetationcuttingalongmostofthereach.Managementofemergentaquaticmacrophytesisalsoevaluatedintheindicator A12, but only in the case of Low-Energy sinuous, meandering or anabranching channels (see Guide forCompilationoftheEvaluationFormsfordetails).

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A3.5 ChannelAdjustments

This set of indicators aims to assess channel adjustments (planimetric and verticalchanges) which have occurred in previous decades. Only channel adjustments related tohumanimpactsshouldbequantified,thereforeitiscrucialtoidentifythecontrollingfactorsofsuchadjustments.Althoughchanneladjustmentsareassessedusingasimplifiedmethod,inmost cases it should be possible to obtain a reliable interpretation of their causes byconsidering the magnitude of these adjustments, as well as the type and frequency ofhumanimpactsatthecatchmentandreachscale.Thislatterinformationshouldbeavailablefrom the analysis of the previous set of indicators (i.e., indicators of artificial elements).These indicators, however, do not provide a detailed reconstruction of past channelevolution (i.e., channel evolutionary trajectory) but only an overall evaluation of pastchannel instability. Since these indicators are based on a comparison with a historicalcondition,onlyadjustments inchannelformareconsidered,whilepossibleadjustments inbed substrate (e.g., armouring, clogging, burial or siltation) are not included and areseparatelyassessedbytheindicatorF10.

Although the indicators of channel adjustments are based on an analysis of changesoccurringoverpastdecades, thehistoricalmorphology isnotconsideredasa ‘reference’condition. In fact, these indicators aim to evaluate channel instability as evidence ofalterationrelatedtohumanfactors.

Sincethetimeintervalsuitableforthistypeofevaluationisoftheorderofapproximately50 – 100 years, should the rivermorphology havebeenartificiallymodified inhistoricaltimesbefore this time interval (e.g.during the18thcentury),as isoften thecase inmanyEuropean fluvial systems, these historical condition should not be considered for theevaluationof channel instability. Even in suchcases, theevaluation shouldbe carriedoutwithreferencetothesametimeinterval (50–100years).Thiscouldprobablyresults inaconditionofartificial ‘stability’relatedtothefixedchannelconfiguration,however insuchcasesthealterationsrelatedtotheartificialconditionsarewidelytakenintoaccountbytheindicatorsofartificialelementsand functionality.Note,however, thata fixedchannelwillnot necessarily be stable: although some types of adjustment will be prevented (e.g.wideningormeanderinginariverwithfixedbanks),othertypesofchangesarestillpossible(e.g.narrowing,aggradation).

A3.5.1 CA1:Adjustmentsinchannelpattern

DESCRIPTION

This indicator evaluates the occurrence and intensity of adjustments in channelmorphological configuration, i.e. the change in channel pattern (sinuous, meandering,braided,etc.).Achangeinchannelpatternduringpastdecadesisgenerallyasymptomofanalteration of some of the processes controlling channel morphology (in particular of thedriving variables, i.e. flow regime and sediment transport). Significant changes in channelpattern cause an alteration of river physical habitats related to the different channelmorphologies.

Channelpatternchangesduetodirectartificialinterventionsarealsoconsideredbythisindicator (e.g. abraided channelwhichmoves towarda single-thread channelbecauseof

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channelization; or ameandering channel becoming sinuous because of artificialmeandercutting). However, the cases when a natural cause of channel adjustments is clearlyrecognized (e.g. a landslide dam or a volcanic eruption which determines the channelpattern change) are not evaluated as an alteration. Furthermore, should the reach haverecently been subject to a morphological river restoration (e.g. removal of artificialconstraints or “morphological reconstruction”), the indicator CA1 is not applied (nor isindicator CA2). In fact, channel pattern change from a former altered situation is notconsidered as a negative channel adjustment (note that possible positive effects ofrestorationactivitiesarealreadytakenintoaccountthroughtheimprovedfunctionalityandthereductionofartificialelements).

TheassessmentofthefirsttwoindicatorsCA1andCA2isbasedontheobservationandanalysisofaerialphotos,comparingthecurrentconditionswitharepresentative,historicalsituation. Since aerial photos suitable for this type of assessment are variable acrossEuropean countries, a range between about the 1930s and 1960s is suggested. Aerialphotos suitable for these indicators should possibly have a homogeneous (scale wise)nationalcover,withsufficientresolutionforthistypeofassessment.Forexample,inItalyahomogeneous national cover of aerial photos dated 1954-55 (IGM GAI) is used (scale ofabout1:33.000).ThechoiceofthistimeintervalisalsomotivatedbythefactthatformostItalian rivers, the most significant part of the planimetric adjustments over the last 100yearsgenerallyoccurredfromaboutthe1950stotheearly1990s(RinaldiandSimon,1998;Surian andRinaldi, 2003; Surian et al., 2009), in coincidencewith economic developmentafterWorldWarII.AsimilarrationaleisapplicabletomanyotherEuropeancountries(e.g.,LiébaultandPiégay,2002;Wyżga,2008).

In the countries where aerial photos with these characteristics are not available,historicalmapswhichareevaluatedtobesuitableforthisanalysiscanbeconsidered,eveniftheintervaloftimeisslightlyprecedenttothe1930s(e.g.,theCassinihistoricalmapsinIrelandandearlyOrdnanceSurveymapsintheUK).

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) Measurements: Remote sensing / GIS analysis

The indicatorCA1 isappliedtoallrivertypes.However,thepotentialofaerial imageryanalysisislimitedbystreamsize,vegetationcoverandtheresolutionoftheimagerythatisavailable.Wherestreamsaretoosmalltobeobservedandquantifiedbyaerialphotos,theindicatorCA1(aswellasCA2)isnotapplied.Afixedthresholdinstreamsizeisavoided,buttheoperatorshouldevaluatewhethertheresolutionofavailableaerialphotosissufficienttocarryouttheassessment.

The indicator is applied both to confined and partly confined - unconfined, althoughsomedifferencesintheclassesexist.Inthecaseofconfinedchannels,onlytwoclassesaredistinguished(AandB)becauseasignificantchangeinchannelpattern(e.g.frombraidedtosingle-thread)and/orinchannelwidth(channelnarrowing:seeCA2)consequentlyleadstoa transformation into a partly confined or unconfined channel. In the cases of partlyconfined - unconfined channels, the assignation to classB orC depends onwhether thechange has occurred between similarmorphologies (e.g. frommeandering to sinuous) or

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between markedly different morphologies (e.g. from braided to sinuous), as defined inTable7.TableA3.9Classesforthedifferentpossibleadjustmentsinchannelmorphologies.Morphologies:ST=straight,S=sinuous,M=Meandering,W=Wandering,B=Braided,A=Anabranching;ó =changeinbothdirections.Class:B=changetoasimilarmorphology;C=changetoamarkedlydifferentmorphology.

Morphology Class Morphology Class ST ó S B S ó A B ST ó M C M ó W C ST ó W C M ó B C ST ó B C M ó A B ST ó A C W ó B B S ó M B W ó A C S ó W C B ó A C S ó B C

Inmanycases,aqualitativeobservationofthechannelpatterninthetwoaerialphotosissufficient toevaluatewhethera significant channelpatternadjustmenthasoccurred (e.g.frombraided to single-thread). In other cases,measurementof some indices for definingchannelmorphology(sinuosityindex,braidingindex,etc.)maybenecessary.Measurementof channel pattern indices requires a GIS analysis, including the georectification of theanalysedimages.

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EXTENDEDANSWERS

Confinement type Confined

Range of application

Not evaluated in the case of too small streams where resolution of available aerial photos is insufficient to allow for the assessment. It does not apply to the case of restored channels which were artificially fixed during the 1930s - 1960s.

A Absence of changes of channel pattern from 1930s-1960s. B Change of channel pattern from 1930s-1960s.

Confinement type Partly confined or unconfined

Range of application

Not evaluated in the case of too small streams where resolution of available aerial photos is insufficient to allow for the assessment. It does not apply to the case of restored channels which were artificially fixed during the 1930s - 1960s.

A Absence of changes of channel pattern from 1930s-1960s. B Change to a similar channel pattern from 1930s-1960s (TableA3.9). C Change to a different channel pattern from 1930s-1960s (TableA3.9).

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassC

FigureA3.63Adjustmentsinchannelpattern.(On the left aerial photo dated 1954, on the right the current situation).Class A: the channelmaintains a prevailingbraidedpattern,althoughchannelnarrowingoccurred.ClassB:changefromwanderingtosinuous.ClassC:changefrombraidedtosinuous.

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A3.5.2 CA2:Adjustmentsinchannelwidth

DESCRIPTION

Thisindicatorevaluatestheoccurrenceandamountofchangesinchannelwidthfromaperiod included in the interval 1930s - 1960s to present day. River channels can showconsiderable change in channel width while maintaining their general channel patternmorphology, because of direct artificial interventions (e.g. artificial narrowing, groynes,etc.), but also because of an alteration of the driving variables controlling channelmorphology (channel-forming and sediment discharges). The existence of significantadjustmentsinchannelwidthvariationsinatemporalintervalof50-80yearsisconsideredhereasevidenceofmorphologicalinstability,andmayhavecausedstrongphysicalhabitatmodifications.The indicatoralso includesthosecaseswherechange inchannelwidthwascaused by direct artificial interventions (e.g. narrowing of a braided channel followingchannelization).AsforCA1,whenanaturalcauseisclearlyrecognized(e.g.alandslidedamor a volcanic eruption which determines the channel pattern change), the channeladjustmentisnotevaluatedasanalteration.Furthermore,inthecaseofariverwhichwasartificiallyfixedinthe1930s–1960sandhasbeenrecentlysubjecttoamorphologicalriverrestoration (e.g. removal of artificial constraints or “morphological reconstruction”), thisindicatorisnotapplied.

In the countries where aerial photos with these characteristics are not available,historicalmapswhichareevaluatedtobesuitableforthisanalysiscanbeconsidered,eveniftheintervaloftimeisslightlyprecedenttothe1930s(e.g.,theCassinihistoricalmapsinIrelandandearlyOrdnanceSurveymapsintheUK).

Spatial scale Longitudinal: Reach Lateral: Entire floodplain (including recent terraces) measurements: Remote sensing / GIS analysis

Asforthepreviousindicator,thisindicatorisappliedtoallrivertypes,excludingthecaseof streams which are too small to be observed and quantified by aerial photos. A fixedthreshold in stream size is avoided, but the operator should evaluate whether theresolutionofavailableaerialphotosissufficienttocarryouttheassessment.

The indicator is applied both to confined and partly confined - unconfined, althoughsomedifferences intheclassesexist. Inconfinedchannels,onlytwoclasses(AandB)aredefined(infactsignificantchannelnarrowingwoulddetermineachangetoanunconfinedchannel).Measurementof changes inchannelwidth requiresaGISanalysis, including thegeorectification of the analysed images, the digitizing of channel margins and themeasurementofthechannelwidth.

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EXTENDEDANSWERS

Confinement type Confined

Range of appl ication

Not evaluated in the case of too small streams where resolution of available aerial photos is insufficient to allow for the assessment. It does not apply to the case of restored channels which were artificially fixed during the 1930s - 1960s.

A Absent or limited changes in channel width (≤ 15%) from 1930s-1960s. B Changes in channel width > 15% from 1930s-1960s. Confinement type Partly confined or unconfined

Range of appl ication

Not evaluated in the case of too small streams where resolution of available aerial photos is insufficient to allow for the assessment. It does not apply to the case of channels which were artificially fixed during the 1930s - 1960s and have then been restored.

A Absent or limited changes in channel width (≤ 15%) from 1930s-1960s. B Moderate changes in channel width (15÷35%) from 1930s-1960s. C Intense changes in channel width (> 35%) from 1930s-1960s.

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ILLUSTRATEDGUIDE

ClassA

ClassB

ClassC

FigureA3.64Adjustmentsinchannelwidth.(Ontheleftaerialphotodated1954,ontherightthecurrentsituation).ClassA:verylimitedchannelnarrowing(≤15%).ClassB:channelnarrowingfrom15%to35%ofchannelwidthin1930s-60s.ClassC:veryintensechannelnarrowing(>35%).

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A3.5.3 CA3:Bed-leveladjustments

DESCRIPTION

Thisindicatoraccountsfortheoccurrenceandamountofbed-leveladjustments(incisionoraggradation).Bed-levelchanges inalluvialchannelsmaybecausedbychangesofsomefactorcontrollingchannelmorphology,particularlybyalterationsof flowand/orsedimentdischarge.Whenbed-leveladjustmentsoccuroverarelativelyshort timeperiod, theyaregenerally related to some human impact (e.g. land use changes at the catchment scale,dams, sediment mining, etc.). They are considered among the most relevant physicalalterations affecting a number of processes (e.g. lateral connection with the floodplain,alterationofin-channelphysicalhabitats,etc.).

Spatial scale Longitudinal: Reach Lateral: Channel Measurements: Data from cross-sections / longitudinal profiles, field survey

This indicator is based on existing data (e.g. longitudinal profiles or cross sections),information from existing literature, and field evidence of bed-level changes. Differentlyfromplanimetricchanges,inthiscasebed-levelchangesarereferredtoalargertimeperiod,i.e.aboutthelast100years.This isrelatedtothefactthat,accordingtoexistingresearch(e.g.,SurianandRinaldi,2003;Surianetal.,2009;LiébaultandPiégay,2002;Liébaultetal.,2012), one or more phases of incision followed a period of predominant aggradation orequilibriumoccurringuntilabouttheendofthe19thcentury inmanyEuropeancountries.Thissimplificationallowsabetterutilizationoffieldevidence,consistingofanevaluationofthe differences in elevation between amodern floodplain and recent terraces, the lattercoincidingwith the historical floodplain before the incision (Rinaldi, 2003; Liébault et al.,2012).Theseobservationscanalsobesupportedbytheanalysisofaerialphotos,whichcanallowthecollectionofdetailedchronologicalinformationonthesurfaceswheredifferencesinelevationaremeasuredinthefield.

On the basis of available data and/or field evidence and survey, an evaluation of therange of bed-level changes (rather than a precise value) is obtained. In the cases of anabsolute lack of data, field evidence or other sources of information, this indicator isomittedandisnotincludedinthefinalscore.

Similarly toCA1 andCA2, this indicatorappliesboth toconfinedandpartly confined -unconfined,butwithsomedifferences.Inthecaseofpartlyconfined-unconfinedchannels,aclassC2isdefinedtoaccountforcasesofdramaticchangesinbedelevation(>6m),whichareveryunusualinthecaseofconfinedchannels.

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EXTENDEDANSWERS

Confinement type Confined

Range of applicat ion Not evaluated in the case of absolute lack of data and field evidence

A Negligible bed-level changes (≤ 0.5 m). B Limited or moderate bed-level changes (0.5÷3 m). C Intense bed-level changes (> 3 m). Confinement type Partly confined or unconfined

Range of appl ication Not evaluated in the case of absolute lack of data and field evidence

A Negligible bed-level changes (≤ 0.5 m): bed elevation unchanged due to altimetric stability or to recovery by aggradation of a previous phase of incision (e.g. due to a weir).

B Limited or moderate bed-level changes (≤ 3 m). Incised channel: differences in elevation exist between new floodplain (if existing) and recent terraces, but in many cases not evident. Aggraded channel: bed-elevation higher than floodplain elevation.

C1

Intense bed-level changes (3÷6 m). Highly incised channel: very evident differences in elevation between new floodplain (if existing) and recent terraces, with the presence of evidence in several forms, including high and unstable banks, destabilization of transversal structures, exposed bridge piers, etc. Highly aggraded channel: marked differences in elevation between channel bed (much higher) and floodplain.

C2 Very intense bed-level changes (> 6 m). Exceptionally incised channel (e.g. following intense mining activity in the past). or exceptionally aggraded channel Usually, data or reliable information about such important changes exist

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ILLUSTRATEDGUIDEClassA

ClassB

ClassC1

ClassC2

FigureA3.65Bed-levelchanges.Class A: negligible incision (≤ 0.5m).Class B: incision from limited tomoderate (from 0.5 to 3m).Class C1: intenseincision(>3m).ClassC2:veryintenseincision(>6m)causingthecompleteerosionofthealluvialdeposits.

FIELDEVIDENCE

1

2

FigureA3.66Fieldevidenceofincision.(1) Exposedbridgepiers. (2)Differences in levelbetweenmodern (post– incision) floodplainand recent terrace (thelattercorrespondingtothepre–incisionfloodplain).

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1

2

FigureA3.67Estimationoftheamountofincisionbasedondifferencesinelevationamongsurfaces.(1) Measurement of difference in elevation (ΔZ) between modern floodplain and recent terrace (pre- incisionfloodplain);(2)measurementofdifferenceinelevationbetweenthetopofgravelonanerodingbank(correspondingtothetopofbarsbeforeincision)andtopofpresentchannelbars.

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A3.6 ScoresForeach indicator, thepartial score relative toclassesA,BorCmustbecircled in the

appositecolumnontheright(firstcolumnontherightsideoftheanswers).Inthefollowingcolumn, the progressive score is reported, so that the total deviation is immediatelyavailable at theendof the compilationof theevaluation form. In the last columnon theright (inside the dotted lines), operator should express a degree of confidence in theanswer, considering three possible cases: (1) High, (2) Medium, (3) Low. This can beindicatedbetweenclassAandB,orbetweenBandC.Asimplifiedestimationoftheoveralluncertaintydegreeassociatedwiththefinalevaluationcanbeobtainedthatistherangeofvariationofthefinalscore.Anexampleoftheprocedurecanbevisualizedinthecompiledevaluationform(seelater).

Forsome indicators, twoadditional scores (“extra-penalties”of6and12, respectively)canbeaddedincaseofextremelydense,dominantpresenceofartificialelementsalongthereach.ThisruleconcerntheindicatorsA4,A6,A7,andA9,andwasincludedtoadequatelyrankriverreacheswithonlyoneorjustafewtypesofartificialelementsbutatverylargeextensionsand/ordensity,heavilyaffectingtheoverallmorphologicalconditions.

On the bottom of the evaluation form, the Morphological Alteration Index, theMorphologicalQualityIndexandtheHydro-MorphologicalQualityIndexarecalculated.TheMorphologicalAlterationIndex(MAI)iscalculatedas:

MAI=Stot/Smax

whereSmaxisthemaximumpossibledeviationforthegivenstreamtypology(itcorrespondstothesumoftheclassCscoresforallthequestionsapplicabletothestudycase).TheMorphologicalQualityIndex(MQI)isexpressedas:

MQI=1–MAI

TheHydro-MorphologicalQualityIndex(HMQI)isexpressedas:

HMQI=1–Stot/Smax

whereStotincludethescoreoftheadditionalindicatorA1H.

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A3.7 Sub-indicesGiventhestructuredividedintovariousaspectsandcategories,itispossibletocalculate

aseriesofsub-indices, that is, tosub-dividethetwomain indicesMAIandMQI intotheircomponents.Thiscanbeusefulforidentifyingthenegativeandpositivepointsofareach.

Thesub-indicesoffunctionality,artificiality,andchanneladjustments(or“verticalsub-indices”)canbeobtainedasfollows:1. FUNCTIONALITY

MAIF=SFtot/Smax

MQIF=(SFmax/Smax)–MAIF=(SFmax–SFtot)/Smax

where

SFtot=F1+…+F13(sumofscoresofappliedFindicators);

Max(SFtot)=Max(F1)+…+Max(F13)(sumofmaximumscoresofallFindicators);

Max(SAtot)=Max(A1)+…+Max(A12)(sumofmaximumscoresofallAindicators);

Max(SCAtot)=Max(CA1)+…+Max(CA3)(sumofmaximumscoresofallCAindicators);

Max(Stot)=Max(SFtot)+Max(SAtot)+Max(SCAtot)(sumofmaximumscoresofallindicators);

Sna(F)=sumofmaximumscoresofnotappliedFindicators;

Sna=sumofmaximumscoresofnotappliedF,A,CAindicator;

SFmax=Max(SFtot)–Sna(F);

Smax=Max(Stot)–Sna.

2. ARTIFICIALITY

MAIA=SAtot/Smax

MQIA=(SAmax/Smax)–MAIA=(SAmax–SAtot)/Smax

where:

SAtot=A1+…+A12(sumofscoresofappliedAindicators);

Max(SFtot)=Max(F1)+…+Max(F13)(sumofmaximumscoresofallFindicators);

Max(SAtot)=Max(A1)+…+Max(A12)(sumofmaximumscoresofallAindicators);

Max(SCAtot)=Max(CA1)+…+Max(CA3)(sumofmaximumscoresofallCAindicators);

Max(Stot)=Max(SFtot)+Max(SAtot)+Max(SCAtot)(sumofmaximumscoresofallindicators);

Sna(A)=sumofmaximumscoresofnotappliedAindicators;

Sna=sumofmaximumscoresofnotappliedF,A,CAindicator;

SAmax=Max(SAtot)–Sna(A);

Smax=Max(Stot)–Sna.

3. CHANNELADJUSTMENTS

MAICA=SCAtot/Smax

MQICA=(SCAmax/Smax)–MAICA=(SCAmax–SCAtot)/Smax

where:

SCAtot=CA1+…+CA3(sumofscoresofappliedCAindicators);

Max(SFtot)=Max(F1)+…+Max(F13)(sumofmaximumscoresofallFindicators);

Max(SAtot)=Max(A1)+…+Max(A12)(sumofmaximumscoresofallAindicators);

Max(SCAtot)=Max(CA1)+…+Max(CA3)(sumofmaximumscoresofallCAindicators);

Max(Stot)=Max(SFtot)+Max(SAtot)+Max(SCAtot)(sumofmaximumscoresofallindicators);

Sna(CA)=sumofmaximumscoresofnotappliedCAindicators;

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Sna=sumofmaximumscoresofnotappliedF,A,CAindicator;

SCAmax=Max(SCAtot)–Sna(CA);

Smax=Max(Stot)–Sna.

Tomaketheanalysismoreeffective,thesub-indicescanberelatedtothemaximumvaluethattheycanreachforagivencategory(functionality,artificiality,channelchanges).Forthispurpose,theoverallvalueofMAIandMQIisdividedinthepartrelativetoeachcategoryasfollows:

1. FUNCTIONALITY

MAIFmax=MQIFmax=SFmax/Smax

2. ARTIFICIALITY

MAIAmax=MQIAmax=SAmax/Smax

3. CHANNELADJUSTMENTS

MAICAmax=MQICAmax=SCAmax/Smax

Notethat,incaseofadditionalscoresfortheindicatorsA4,A6,A7,A9suchthatStot>Smax,thesumofthethreesub-indicesMAIF+MAIA+MAICAis>1.

Similarly,continuity,morphology andvegetation sub-indices (or “horizontal sub-indices”) canbeobtained. For thispurpose,someelementofartificialityneedstobesharedinmorecategories: insuchcasesthescoreassignedtoagivenindicatorissimplydividedbythenumberofcategories.Thesub-indicesaredefinedasfollows.

1. CONTINUITYMAIC=MAICL+MAICLA

MQIC=MQICL+MQICLAwhere:Cisforcontinuity,CLisforlongitudinalcontinuityandCLAisforlateralcontinuity1.1 LONGITUDINALCONTINUITYMAICL=(F1+A1+A2+A3+A4/2+A5)/SmaxMQICL=(SCLmax/Smax)–MAICL

where:SCLmax=Max(SCLtot)–Sna(CL);Max(SCLtot)=Max(F1)+Max(A1)+Max(A2)+Max(A3)+Max(A4/2)+Max(A5)(sumofmaximumscoresofallCLindicators);

Sna(CL)=sumofmaximumscoresofnotappliedCLindicators.

1.2 LATERALCONTINUITYMAICLA=(F2+F3+F4+F5+A6/2+A7)/SmaxMQICLA=(SCLAmax/Smax)–MAICLA

where:SCLAmax=Max(SCLAtot)–Sna(CLA);Max(SCLAtot)=Max(F2)+Max(F3)+Max(F4)+Max(F5)+Max(A6/2)+Max(A7)(sumofmaximumscoresofallCLAindicators);

Sna(CLA)=sumofmaximumscoresofnotappliedCLAindicators.

2. MORPHOLOGY

MAIM=MAICM+MAICS+MAISMQIM=MQICM+MQICS+MQISwhere:

Misformorphology,CMisformorphologicalpattern,CSisforcross-sectionconfigurationandSisforsubstrate.

2.1 MORPHOLOGICALPATTERN

MAICM=(F6+F7+F8+A6/2+A8+CA1)/SmaxMQICM=(SCMmax/Smax)–MAICM

where:SCMmax=Max(SCMtot)–Sna(CM);Max(SCMtot)=Max(F6)+Max(F7)+Max(F8)+Max(A6/2)+Max(A8)+Max(CA1)(sumofmaximumscoresofallCMindicators);

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Sna(CM)=sumofmaximumscoresofnotappliedCMindicators.

2.2 CROSS-SECTIONCONFIGURATION

MAICS=(F9+A4/2+A9/2+A10/2+CA2+CA3)/SmaxMQICS=(SCSmax/Smax)–MAICS

where:SCSmax=Max(SCStot)–Sna(CS);Max(SCStot)=Max(F9)+Max(A4/2)+Max(A9/2)+Max(A10/2)+Max(CA2)+Max(CA3)(sumofmaximumscoresofallCSindicators);Sna(CS)=sumofmaximumscoresofnotappliedCSindicators.

2.3 SUBSTRATE

MAIS=(F10+F11+A9/2+A10/2+A11)/SmaxMQIS=(SSmax/Smax)–MAIS

where:SSmax=Max(SStot)–Sna(S);Max(SStot)=Max(F10)+Max(F11)+Max(A9/2)+Max(A10/2)+Max(A11)(sumofmaximumscoresofallSindicators);Sna(S)=sumofmaximumscoresofnotappliedSindicators.

3. VEGETATION

MAIVE=(F12+F13+A12)/SmaxMQIVE=(SVEmax/Smax)–MAIVEwhere:

VEisforvegetation;SVEmax=Max(SVEtot)–Sna(VE);Max(SVEtot)=Max(F12)+Max(F13)+Max(A12)(sumofmaximumscoresofallVEindicators);

Sna(VE)=sumofmaximumscoresofnotappliedVEindicators.

Asbefore,thesub-indicescanberelatedtothemaximumvaluethattheycanreachforagivencategory,bydividingoverallvalueofMAIandMQIinthepartrelativetoeachcategoryasfollows:

1. CONTINUITY

MAICmax=MQICmax=SCmax/Smax

where:SCmax=Max(SCtot)–Sna(C)=SCLmax+SCLAmax;Max(SCtot)=Max(SCLtot)+Max(SCLAtot)(sumofmaximumscoresofallCindicators,orsumofmaximumscoresofallCLandCLAindicators);Sna(C)=Sna(CL)+Sna(CLA)(sumofmaximumscoresofnotappliedCindicators,orsumofmaximumscoresofnotappliedCLandCLAindicators).

2. MORPHOLOGY

MAIMmax=MQIMmax=SMmax/Smax

where:SMmax=Max(SMtot)–Sna(M)=SCMmax+SCSmax+SSmax;Max(SMtot)=Max(SCMtot)+Max(SCStot)+Max(SStot)(sumofmaximumscoresofallMindicators,orsumofmaximumscoresofallCM,CSandSindicators);

Sna(M)=Sna(CM)+Sna(CS)+Sna(S)(sum of maximum scores of not applied M indicators, or sum of maximum scores of not applied CM, CS and Sindicators).

3. VEGETATION

MAIVEmax=MQIVEmax=SVEmax/Smax

EXAMPLEOFCOMPILEDEVALUATIONFORMAn example of a compiled evaluation form is reported as follows. This example is useful in understanding how to

compiletheformsandinaccountingfortheconfidencedegreeinthecalculationoftherangeofvariabilityofMQI.

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Morphological Quality Index (MQI)

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EVALUATION FORMS FOR PARTLY CONFINED AND UNCONFINED CHANNELSVersion 2 - October 2016

GENERALITYDate 20 / 04 / 20 16 Operators J. Smith

Catchment Reform Stream/river Reform River

Upstream limit confluence Reform branch Downstream limit nearby Willington

Segment code 4 Reach Code 4_3 Reach length (m) 2.4 km

DELINEATION OF SPATIAL UNITS 1. Physiographic setting

Physiographic context P M=Mountains, H=Hills, P=Plain Landscape unit High plain

2. ConfinementConfinement degree (%) 10- 90 >90, 10-90, ≤10

Confinement index >n 1-1.5, 1.5-n, >n (n=5 single-thread or anabranching; n=2 braided or wandering)

Confinement class PC PC=Partly confined, U=Unconfined

3. Channel morphologyAerial photo or satellite image Aerial Flight Reform Region 2007 (name, year)

Sinuosity index ∼ 1.2 1-1.05, 1.05-1.5, >1.5Braiding index ∼ 1.3 1-1.5, >1.5 Anabranching index 1 1-1.5, >1.5

River Type (BRT, Basic River Typology) W ST=Straight, S=Sinuous, M=Meandering,

W= Wandering, B= Braided, A= Anabranching

4. Other elements for reach delineationUpstream Tributary Downstreamchange in geomorphic units, bed slope discontinuity, tributary, dam, artificial elements, change in confinement

and/or size of the floodplain, changes in grain size, other (specify)

FURTHER CHARACTERIZATIONDrainage area (at the downstream limit) (km2) 760

Mean bed slope, S 0.0033 Mean channel width, W (m) 42Bed sediment (dominant) G-C C=Clay, Si=Silt, Sa=Sand, G=Gravel, C=Cobbles, B=Boulders

Bed configuration BR=bedrock, C=Cascade, SP=Step Pool, PB=Plane bed, RP=Riffle Pool, DR=Dune rippleA= Artificial, NC= not classified (high depth or strong alteration)

River Type (ERT, Extended River Typology) from 0 to 22 (GF= Groundwater-Fed)Unit stream power (ω=γQS/W) (when available) >10 ≤10, >10 W m-1 Energy setting LE=Low Energy

Additional available data / informationSediment size, D50 (mm) 35 Unit Ba(SU) Be=Bed, Ba=Bar (SU=surface layer, SUB=sublayer)

Discharges E M=measured, E=estimated, NA=not available

Gauging station (if M) Mean annual discharge (m3/s) 24 Q1.5 or Q2 (m3/s) 235Maximum discharges (indicate year and Q when known) Intense flood in 2009

GEOMORPHOLOGICAL FUNCTIONALITYContinuity part. prog. conf.F1 Longitudinal continuity in sediment and wood flux

Check dam intercepting bedload and creating a discontinuity of channel forms (disappearence of bars)

F2 Presence of a modern floodplain

Not evaluated in the case of mountain streams along steep (>3%) alluvial fansSome uncertainty for part of the reach whether it is a modern floodplain or a low terrace

confidence level between A and B conf:confidence level in the answer, with M=Medium, L=Low (High is omitted) confidence level between B and C part.: partial score (to circle)

Presence of a discontinuous (10÷66%) but wide floodplain or >66% but narrowB2 Presence of a discontinuous (10÷66%) and narrow floodplain

Absence of a floodplain or negligible presence (≤10% of any width)

prog.: MQI progressive score

Strong alteration (discontinuity of channel forms and interception of sediment and wood)

Presence of a continuous (>66% of the reach) and wide floodplainB1

C

A Absence of alteration in the continuity of sediment and woodBC

A

Slight alteration (obstacles to the flux but with no interception)

M

35 5

0

8

2

5

0

3 +2

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Morphological Quality Index (MQI)

2 of 5

F4

Not evaluated in the case of Low Energy ERT types from 17 to 22 and Groundwater-Fed streams

F5

MorphologyMorphological patternF7 Planform pattern

F8 Presence of typical fluvial landforms in the floodplain

Cross-section configurationF9

Bed structure and substrateF10

Not evaluated for deep rivers when it is not possible to observe the channel bed

F11

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

Vegetation in the fluvial corridorF12

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

BC

C

AWidth of functional vegetation

Significant presence of large wood along the whole reach (or "wood transport" reach)

Negligible presence of large wood for >50% of the reach

High width of functional vegetation

21

Natural heterogeneity of bed sediments and no significant armouring, clogging or burialEvident armouring or clogging for ≤50% of the reachEvident armouring or clogging (>50%), or burial (≤50%), or occasional substrate outcrops

3

AB

C1C2

0

APresence of a potentially erodible corridor

Complete absence (≤2%) or widespread presence (>50%) of eroding banks by mass failures

Presence of a wide potentially erodible corridor (EC) for a length >66% of the reach

Negligible presence of large wood for ≤50% of the reachB

BC

A

C

B

Bank erosion occurs for >10% and is distributed along >33% of the reachProcesses of bank retreat

A

13

Variability of the cross-section

Presence of alteration (cross-section homogeneity) for a limited portion of the reach (≤33%)Presence of alteration (cross-section homogeneity) for a significant portion of the reach (>33%) 5

Absence (≤5%) of alteration of the cross-section natural heterogeneity (channel depth)

Evident burial (>50%), or substrate outcrops or alteration by bed revetments (>33% of the reach)

Presence of a potentially EC of any width for ≤33% of the reach

Presence of floodplain landforms (oxbow lakes, secondary channels, etc.)Presence of traces of landforms (abandoned during the last decades) but with possible reactivationComplete absence of floodplain landforms

BC

A

A

Absence (<5%) of alteration of the natural heterogeneity of geomorphic units and channel widthAlterations for a limited portion of the reach (≤33%)Consistent alterations for a significant portion of the reach (>33%)

Structure of the channel bed

0

3

0

Bank erosion occurs for ≤10%, or for >10% but is concentrated along ≤33% of the reach

2

23

2

3

3

035

0

0

8

10

or significant presence (>25%) of eroding banks by mass failures 2

Presence of a potentially EC of any width for 33-66% of the reach or for >66% but narrow

16

13

21

23

BC

A

56

2

BC

3

02

0

Medium width of functional vegetationLow width of functional vegetation

Presence of in-channel large wood

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Morphological Quality Index (MQI)

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F13 Linear extension of functional vegetation

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

ARTIFICIALITYpart. prog. conf.

A1M Upstream alteration of flows with potentially relevant effects on channel morphology

A1H Upstream alteration of flows without potentially relevant effects on channel morphology

Evaluated for the application of the HMQI

A2 Upstream alteration of sediment discharges

A dam upstream

A3 Alteration of flows in the reach

A4 Alteration of sediment discharge in the reach

Where transversal structures, including bed sills and ramps (see A9), are >1 every d1, add 6Where structures, including bed sills and ramps (see A9), are >1 every d2, add 12

where d1=150 m and d2=100 m in steep channels, or d1=750 m and d2=500 m in channels with S≤1%Two weirs

B2

C2

B

C

C1

Alteration of longitudinal continuity in the reach

Dams (drainage area 33-66%) and/or check dams/weirs with total bedload interception(drainage area >66% or at the upstream boundary)

ABC

A

C

A

B1Dams (area 5-33%) and/or check dams/weirs with total bedload interception (area 33-66%)and/or check dams/weirs with partial interception (area >66%)

or presence of a dam or artificial reservoir at the downstream boundary (any bed slope)

Absence of structures for the interception of sediment fluxes (dams, check dams, abstraction weirs)

03

3

6

12

BC 6

No significant alteration (≤10%) of channel-forming discharges and with return interval>10 yearsSignificant alteration (>10%) of discharges with return interval>10 yearsSignificant alteration (>10%) of channel-forming discharges

A

BChannels with S≤1%: consolidation check dams and/or abstraction weirs ≤1 every 1000 mSteep channels (S>1%): consolidation check dams ≤1 every 200 m and/or open check dams

Steep channels (S>1%): consolidation check dams >1 every 200 m and/or retention check dams

0

Linear extension of functional vegetation >90% of maximum available lengthLinear extension of functional vegetation 33÷90% of maximum available length

29

5

0

and/or reach immediately downstream of a hydropower reservoir

6

0

26

Significant alteration (>10%) of discharges with return interval>10 years

Dam at the upstream boundary of the reach

Absence or negligible presence of structures for the interception of sediment fluxes

Significant alteration (>10%) of channel-forming discharges

Dams for drainage area >66%

3

9

35

39

0

4

6

A

No significant alteration (≤10%) of channel-forming discharges and with return interval>10 years

Channels with S≤1%: consolidation check dams and/or abstraction weirs >1 every 1000 m

A Absence of any type of structure altering flow discharges (dams or other abstractions) 0B Presence in the catchment of one or more structures altering flow discharges

C Reach located between abstraction and restitution section of hydropower plant 22

Linear extension of functional vegetation ≤33% of maximum available length

11

or release of increased low flows downstream dams during dry seasons

35

3

Upstream alteration of longitudinal continuity

(dams for drainage area ≤5% and/or check dams/abstraction weirs for drainage area ≤33%)

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Morphological Quality Index (MQI)

4 of 5

A5 Crossing structures

Three bridges

Alteration of lateral continuityA6 Bank protections

For a high density of bank protection (>50%) add 6For an extremely high density of bank protection (>80%) add 12

A7 Artificial levees

For a high density of bank-edge levees (>66%) add 6For an extremely high density of bank-edge levees (>80%) add 12

Alteration of channel morphology and/or substrateA8 Artificial changes of river course

In case of historical drainage and dredged works for >50% of the reach, add 6In case of historical drainage and dredged works for >80% of the reach, add 12

(when an additional score for A6 and/or A7 is not already applied)

A9 Other bed stabilization structures

d=200 m in steep channels (S>1%); d= 1000 m in channels with S≤1%

For a high density of bed revetment (impermeable >50% or permeable >80%) add 6For an extremely high density of bed revetment (impermeable >80%) add 12

Two sills

Intervention of maintenance and removalA10 Sediment removal

There is some uncertainty whether the activity in the past was significant

A11 Wood removal

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

C

A

C

BC

A

A

C

A

C

AB

A

C1

B

C2

BC

AB

B

Presence of changes of river course for ≤10% of the reach lengthPresence of changes of river course for >10% of the reach length

Absence of structures (bed sills/ramps) and revetmentsSills or ramps (≤1 every d) and/or revetments ≤25% permeable and/or ≤15% impermeableSills or ramps (>1 every d) and/or revetments ≤50% permeable and/or ≤33% impermeable

Presence of some crossing structures (≤1 every 1000 m in average in the reach)Presence of many crossing structures (>1 every 1000 m in average in the reach)

Sediment removal activity either in the past (last 100 years) and during last 20 years

Absence of removal of woody material at least during the last 20 yearsPartial removal of woody material during the last 20 yearsTotal removal of woody material during the last 20 years

036

0

0Absence of crossing structures (bridges, fords, culverts)

36

02

Absence or localized presence of bank protections (≤5% total length of the banks)Presence of protections for ≤33% total length of the banks (sum of both banks)Presence of protections for >33% total length of the banks (sum of both banks)

Absent or set-back levees, or presence of close and/or bank-edge levees ≤5% bank lengthBank-edge levees ≤50%, or ≤33% in case of total of close and/or bank edge>90%Bank-edge levees >50%, or >33% in case of total of close and/or bank edge>90%

3

0

5

368

0

6

23

41

44

41

41

50

02

52

41

Recent sediment removal activity (last 20 years) but absent in the past (last 100 years)Sediment removal activity in the past (last 100 years) but absent during last 20 years

Revetments >50% permeable and/or >33% impermeable

Absence of recent (last 20 years) and past (last 100 years) significant sediment removal activities

Absence of artificial changes of river course in the past (meanders cut-off, channel diversions, etc.)

M -2

B1B2

34

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Morphological Quality Index (MQI)

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A12 Vegetation management

Not evaluated above the tree-line and in streams with natural absence of riparian vegetation (e.g. north-European tundra)

CA1 Adjustments in channel pattern

Not evaluated in the case of small streams where resolution of aerial photos is insufficient

CA2 Adjustments in channel width

Not evaluated in the case of small streams where resolution of aerial photos is insufficient

CA3 Bed-level adjustments

Not evaluated in the case of absolute lack of data, information and field evidences

Total deviation (MQI): Stot = 65 63÷67

Maximum deviation: Smax = 142 - Sna= 142

where Sna = sum of maximum scores for those indicators that have not been applied

Morphological Alteration Index: MAI = Stot / Smax = 0.46 0.44÷0.47

if Stot>Smax it is assumed MAI=1

Morphological Quality Index: MQI=1-MAI = 0.54 0.53÷0.56

Morphological Quality class of the reach Moderate

0≤MQI<0.3: Very Poor or Bad; 0.3≤MQI<0.5: Poor; 0.5≤MQI<0.7: Moderate; 0.7≤MQI<0.85: Good; 0.85≤MQI≤1.0: Very Good or High

Total deviation (HMQI): Stot + S(A1H) = 76

Hydro-Morphological Quality Index: HMQI=1-Stot+S(A1H) / Smax = 0.46

Hydro-Morphological Quality class of the reach Poor

0≤HMQI<0.3: Very Poor or Bad; 0.3≤HMQI<0.5: Poor; 0.5≤HMQI<0.7: Moderate; 0.7≤HMQI<0.85: Good; 0.85≤HMQI≤1.0: Very Good or High

B

C

Selective cuts and/or clear cuts of riparian vegetation ≤50% of the reach and partial or no cutting 2

5Clear cuts of riparian vegetation >50% of the reach, or selective cuts and/or clear cuts of riparianvegetation ≤50% of the reach but total cutting of aquatic vegetation

A

A

C

036

BAbsence of changes of channel pattern since 1930s - 1960sChange to a similar channel pattern since 1930s - 1960sChange to a different channel pattern since 1930s - 1960s 55

BC

Absent or limited changes (≤15%) since 1930s - 1960sModerate changes (15÷35%) since 1930s - 1960sIntense changes (>35%) since 1930s - 1960s

36

0A

No cutting interventions on riparian vegetation (last 20 years) and aquatic vegetation (last 5 years)

of aquatic vegetation, or no cutting of riparian but partial or total cutting of aquatic vegetation

Limited to moderate bed-level changes (0.5÷3 m)

0

4812

AB

C1C2

Intense bed-level changes (>3 m)Very intense bed-level changes (>6 m)

Negligible bed-level changes (≤0.5 m) 0

65

61

CHANNEL ADJUSTMENTS conf.prog.part.

52

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A3.8 References

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