Thomas Hoffmann

Banff, Sep. 18th 2010

Kananaskis River (Rocky Mnts.)

contents

1. Nature of fluvial (environmental) systems2. Human impact on sediment in the Rhine

catchment– Scientific problem– Data needs GeoCENS

3. Salmon and geomorphology– Scientific problem– Data needs GeoCENS

4. Summary

contents

1. Nature of fluvial (environmental) systems2. Human impact on sediment in the Rhine

catchment– Scientific problem– Data needs GeoCENS

3. Salmon and geomorphology– Scientific problem– Data needs GeoCENS

4. Summary

Rio Beni (Bolivia)

time & space

Environmental systemsare systems that are:• variable in time and

space• physical systems with

a history• self organizing• hierarchical• response is dependent

on spatial scale

Time(years)

Space (m²)

Watershedphysiography

Valleymorphology, river

profiles

Channel reachmorphology, sedimentrouting, channel width

and depth

Habitat unitmorphology, grainsize, bedforms

109101 102 103 104 105 106 107 108

101

102

103

104

105

106

107

time & space

Environmental systemsare systems that are:• variable in time and

space• physical systems with

a history• self organizing• hierarchical• response is dependent

on spatial scale

Timescales of adjustment of channel formcomponent with given length dimension

modified after Montgomery (2004)

100

contents

1. Nature of fluvial (environmental) systems

2. Human impact on the Rhine catchment– Scientific problem

– Data needs GeoCENS

3. Salmon and geomorphology– Scientific problem

– Data needs GeoCENS

4. Summary

problem: soil degradation

• Globally, nearly 2 billionhectares of land are affected byhuman induced degradation ofsoils (UN, 2000)

• Main driver of soil degradation:soil erosion

• Old world: long human impact(several 1000 years)

long term perspective neededGrabenerosion auf einer gerade bestellten RapsflächeM. Firelinghaus

Fluss Regen in der Oberpfalz hat beim Augusthochwasser 2002

Grabenerosion auf einer gerade bestellten RapsflächeM. Firelinghaus

Sources

Floodplains asmajor sinks

source to sink

Floodplains as proxies of environmental change

floodplain sedimentation

Hoffmann et al. (2009, Catena)

baseline SR: 0.5 mm/yr

Increase of mean SRsince approx. 2000 BP

strong human impact

sedimen

tation

rate

[mm/yr]

Increase of erosionIncrease of humanimpact

Problem: link betweenerosion and depositionrates?

Hoffmann et al. (2009, Catena)

Uniform increase of meansedimentation rate

floodplainsedimentation

Fluss Regen in der Oberpfalz hat beim Augusthochwasser 2002

Grabenerosion auf einer gerade bestellten RapsflächeM. Firelinghaus

Sources

Floodplains asmajor sinks

Floodplains as proxies of environmental change

source to sink

Coon Creek (Trimble 1999, Science)

• Cause: Decreased soilerosion due toconservation measures

• Affects: constantsediment delivery

source to sink

connectivitysource to sinkRhine catchment(Lang et al. 2003, Hydrological Processes)

• Cause: Long humanimpact on hillslopeerosion, with varyingdegree of deforestation

• Affects: Buffered anddelayed response offloodplains

what is needed?• Time dependent spatial information of external drivers– human impact

• Location of agricultural areas at different scales:– large scale population distribution– small scale terrain position: slope/valley

• Agricultural practice:– non plough, plough– size of agricultural fields

– climate/hydrology• temperature• precipitation• discharge (magnitude & frequency)

• Time dependent spatial information fluvial response– Sediment flux connectivity hillslope channel– Channel type + morphology (meandering/braiding)

land use history in GermanyRoman population (~2ka BP)Neolithic population (~7 ka BP)

Zimmermann at el (2009)

NorthSea

European Alps

what is needed?• Time dependent spatial information of external drivers– human impact

• Location of agricultural areas at different scales:– large scale population distribution– small scale terrain position: slope/valley

• Agricultural practice:– non plough, plough– size of agricultural fields

– climate/hydrology• temperature• precipitation• discharge (magnitude & frequency)

• Time dependent spatial information fluvial response– Sediment flux connectivity hillslope channel– Channel type + morphology (meandering/braiding)

human impacton the Rhine

before 1850 AD

today

data typesVector• Area:

– land use

– geology

– sediment storage location

• Line:– sediment transport paths

(e.g. river network)

– breaks of sediment transport(e.g. field edges)

• Point:– Stratigraphical record

(slope, floodplain)

– Dating (e.g. 14C ages)

Raster• Topography (DEMs)

• Climate data– temperature

– precipitation

time dependent

data typesVector• Area:

– land use

– geology

– sediment storage location

• Line:– sediment transport paths

(e.g. river network)

– breaks of sediment transport(e.g. field edges)

• Point:– Stratigraphical record

(slope, floodplain)

– Dating (e.g. 14C ages)

Raster• Topography (DEMs)

• Climate data– temperature

– precipitation

time dependent

Necessary meta information!• Time scale• Spatial representativeness

Upscaling of point dataChanging conditions!e.g. changing land use in catchment of a gauging station

• Connectivity between points/objects extrapolation• Quality evaluation!!!

GeoCENS application

• Temporal GoogleEarth• Visualization of time dependent spatial data– Point data, line data and areal data

e.g. visualization of changing land use (arealmaps), 14C data of dated hillslope and fluvialsedimentTime scales: ~10³ yearsFrom sensors to palaeo archives

Salmon &Geomorphology

©http://www.thinksalmon.com

Fish habitat and geomorphology

Strong decline of salmon populations

© http://www.thinksalmon.com

0

10000

20000

30000

40000

50000

60000

1860 1880 1900 1920 1940 1960 1980 2000

ColumbiaRiverCo

mmercialLand

ings

(inTh

ousand

sof

Poun

ds)

years

Chinook CohoSockeye ChumSteelhead Total

Source: WDFW (2002)

the big four (five) H´s

Salmon

Harvest(overfishing)

Hatcheries Hydropower(dams)

Habitat

HistoryAssessment if restoration ispossible © http://www.thinksalmon.com

salmon live cycle and habitats

deep shelteredpools to rest

buried instreambed

shelter to grow,forage and hidefrom predators

spawing: clean gravel ofappropriate size to spawn

+ pools to rest

ocean: foodsupply

off channel wetlands + floodplains:summer rearing habitat andprotection from winter floods

Picture source: http://www.fishex.com/seafood/salmon/salmon life cycles.html

healthy salmon habitats

changes of salmon habitatMon

tgom

ery(200

4)

Snohomish River (Washington)

1870 1990Snohomish River (Washington)

changes of salmon habitat

changes of salmon habitat

Deforestation

loss large woodydebris input into

channels

high input of finesediments into

channel

loss of wetlands &floodplains

Urbanization

decreasing heterogeneity of channel bed

morphology

siltation ofchannel beds

Loss of salmonhabitat

Agriculturalland use

restoration

Understanding of:–Watershed processes (not only channel)• Water, sediment and large wooded debris flux

– Hillslope channel connectivity– Transport within channel

• Coupling of system components and processes– Coupling between processes and channel morphology– Coupling between biology and geomorphology/hydrology

Spatial context

– Disturbance history• Land use history• Channel morphology today and before human impact

Temporal context

which data needed?• High resolution digital elevation

models (DEMs)(esp. LIDAR = Light Detection + Ranging)

– Extraction of channel networks– Mapping of geomorphological

landforms identification ofsediment transport processes

– Classification of channelmorphology

– Reconstruction of formerchannel courses

• Aerial photographs– Mapping of changing channel

pattern– Reconstruction of land use

history– Identification of sediment

sources and storages

Hillshade of LIDAR DEM (1m resolution)Kananaskis country

Hillshade of LIDAR DEM (1m resolution)Kananaskis country

which data needed?

Classification based on Montgomery & Buffington(1997), data source 5m DEM (rescaled 1m LIDAR DEM)

casacadestep pool

planebed

Pool riffle

pool riffleplane bedstep poolcascade

which data needed?• Sediment size = most

important channelcharacteristic forspawning

• Availability of suitablesediment dependent on:– Channel hydraulics

(shear stress)– Sediment supply

(volume and grain size)

Estimation ofsediment size basedon DEM derivedchannel slope anddrainage area

**50 )()( cscs

hsg

D

plane bed channelswood poor pool riffle channelswood forced pool riffle channels

increasing roughness / resistance

which data needed?• High resolution digital elevation

models (DEMs)(esp. LIDAR = Light Detection + Ranging)

– Extraction of channel networks– Mapping of geomorphological

landforms identification ofsediment transport processes

– Classification of channelmorphology

– Reconstruction of formerchannel courses

• Aerial photographs– Mapping of changing channel

pattern– Reconstruction of land use

history– Identification of sediment

sources and storages.

Orthophoto, 1m resolution (2008)

which data needed?

summary

Restoration of salmon habitat onlypossible if we have a goodunderstanding of:

• ecological and geomorphologicalprocesses in salmon bearing rivers

• how these rivers evolved in time

GeoCENS application

• Temporal GoogleEarth• Visualization of time dependent spatial data– Point data, line data and areal data

e.g. visualization of changing land use (arealmaps), changing river habitat (linear features)and salmon populationsTime scale: 10² years (since air photos areavailable)

take home message

geospatial data is

not just xyzt

but

information in ageographical context

take home message

• If we want a large geoscientific community touse GeoCENS we need to integrate spatial andtemporal, e.g.:– Geological, geomorphological maps

– Digital elevation models

– Time dependent land use maps

– �…and derivatives• However: quality concerns must be met

• Visualization tool of spatial temporal data

important for every paleo environmental study

Thanks foryour attention !