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Research ArticleApplication of Electrical Resistivity Tomography Technique forCharacterizing Leakage Problem in Abu Baara Earth Dam Syria
Walid Al-Fares
Department of Geology Atomic Energy Commission PO Box 6091 Damascus Syria
Correspondence should be addressed to Walid Al-Fares cscientific2aecorgsy
Received 11 September 2014 Revised 12 November 2014 Accepted 12 November 2014 Published 11 December 2014
Academic Editor Rudolf A Treumann
Copyright copy 2014 Walid Al-Fares This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Electrical Resistivity Tomography (ERT) survey was carried out at Abu Baara earth dam in northwestern Syria in order to delineatepotential pathways of leakage occurring through the subsurface structure close to the dam body The survey was performed alongtwo straight measuring profiles of 715 and 430m length in up- and downstream sides of the damrsquos embankment The analysis ofthe inverted ERT sections revealed the presence of fractured and karstified limestone rocks which constitute the shallow bedrockof the dam reservoir Several subsurface structural anomalies were identified within the fractured bedrock most of which areassociated with probable karstic cavities voids and discontinuity features developed within the carbonates rocks Moreover resultsalso showed the occurrence of a distinguished subsiding structure coinciding with main valley course Accordingly it is believedthat the bedrock and the other detected features are the main potential causes of water leakage from the damrsquos reservoir
1 Introduction
Water seepage one of the most common problems of earthendams usually occurs either through the reservoirrsquos bedrockor through the embankment-abutment contact This phe-nomenon is often related to geological and tectonic factorsfor example faults fractures and cavities or to internalgeodynamic and filtration processes in and beneath thedam body [1ndash7] Recently Electrical Resistivity Tomography(ERT) is relatively a new developed geophysical techniquewhich becomes one of the principle tools widely used inhydrogeological and engineering applicationsThis techniquehas proven its performance and adequacy in characterizingthe potential paths of water seepage from dams particularlyfrom earthen ones [8ndash14]
In Syria there are more than 160 dams and impoundingreservoirs scattered throughout the country Unfortunatelysome of these dams suffer from infiltration or leakage prob-lems related remarkably to different geological and tectonicfactors Abu Baara dam is one of the earthen dams in Syriawhich suffers from leakage problem The dam is situatedclose to Maarin village at the southern margins of Al-Ghabpull-apart developed along the northern parts of the Dead
Sea Fault System (Figure 1) The purpose of the constructionof this dam was to save some parts of Al-Ghab plain fromrain floods and to meet the arearsquos water needs for irrigationand agricultural development The embankment of AbuBaara dam has a clayey core surrounded from both sidesby filters composed of sands and various mixtures coveredby coarse rockfill to stabilize the dam and protect its clayeycore (Figure 2) The 2345m elevated southwest-northeastoriented dam body is 720m long and 245m high at the floorof Abu Baara main valley courseThe damrsquos lake extends over100 hectares with a maximum dam reservoir storage around76 million cubic meters
In 1988 the dam reservoir was filled up for the first timewith water to inspect the dam before putting it in serviceSubsequently a sharp decrease in stored reservoir water leveland water flow from some piezometric boreholes behindthe dam body was observed This phenomenon occurredrepeatedly in several subsequent seasons particularly whenthe stored damrsquos lake water level rises Accordingly the Direc-torate of Land Reclamation conducted some geoelectricalsurveys (Vertical Electrical Sounding VES) in many parts ofthe damrsquos lakeThe results of the geoelectrical surveys showedthe presence of an intersection of two faults close to the damrsquos
Hindawi Publishing CorporationInternational Journal of GeophysicsVolume 2014 Article ID 368128 9 pageshttpdxdoiorg1011552014368128
2 International Journal of Geophysics
Palmyra
Damascus
HomsHamah
Tartus
Latakia
AleppoAr-Raqqa
Dayr Az-Zawr
Al-Hasakeh
Beirut
Turkey
Jordan
Iraq
Abo Kamal
Med
iterr
anea
n Se
aLe
bano
n
Syria
Iskenderun
Ephemeral stream
(km)
Abu Baara stream
Faults (existence and position) Upper Quaternary clays loams and pebblesPliocene clays marls limestonessandstones and conglomeratesCenomanian-Turonianlimestones and dolomites
0 2
Maarin
Abu Baaradam
N
cN2
cN2
Cr2cm-t
4
3699840099840030
99840036
99840099840022
998400
3599840099840006998400
3599840099840010998400
3599840099840013998400
Darrsquoa
Study area
Q3
Figure 1 Geological map of the study area showing the location of Abu Baara dam modified from [19]
NW SE
Borehole location
23452317
210 m (asl)1
4
2
3
4
1
5
Figure 2 Cross-section in Abu Baara earth dam body with (1) clay core (2 and 3) filters (4) support rockfill and (5) water reservoir
main axis and revealed the presence of some karstic cavesat depth [15] Hence the faulted area was delineated andsealed by a several meters thick clayey layer covering an areaof 16000m2 approximately Nevertheless the water seepageproblem from the damrsquos lake remained unsolved especiallywhen water level rises high in the reservoir Therefore thisproblem may affect the stability and the safety of dam in
the future Accordingly this work was proposed with theobjective of outlining the subsurface structure of Abu Baaradamrsquos reservoir delineating weak zones responsible for waterseepage and understanding deeply the origin of leakageproblem through applying a new developed geophysicaltechnique represented by Electrical Resistivity Tomography(ERT) method close to the damrsquos embankment downstream
International Journal of Geophysics 3
2 Geological and Hydrogeological Settings
Abu Baara dam is located at the extreme southern marginsof Al-Ghab pull-apart basin developed through the ongoingtectonic evolution of the Dead Sea Fault System (DSFS) innorthwestern Syria [16ndash18] The depression of Al-Ghab basinis filled with more than 100m thick Neogene and Quaternarylacustrine and alluvium deposits overlaying uncomfortablydeeply seated Cretaceous limestone [19]
As to local geological setting at Abu Baara dam site thedamrsquos lake floor is composed mainly of Quaternary alluviumclays sands and gravels (Q
3) in addition to carbonate-
siliceous cemented conglomerates (Figure 1) The thicknessof these deposits varies from one to tens of meters insome places The alluvial deposits overlay the Cenomanian-Turonian limestones and dolomites rocks (Cr
2cm-t) that
constitute the bedrock of the damrsquos reservoir These rockswhich are dipping towards the main stream by about 5ndash15 degrees are characterized by extensive fracturing andkarstification which contribute to forming cavities voidsand underground karstic conduits In addition the initialgeological investigations carried out by the Syrian GeneralCompany for Hydraulic Studies revealed the existence ofkarstified zones developed at various depths within thecalcareous rocks in the area On the other hand tectonicdisturbances such as faults of different trends are marked thecarbonates rocks in the region these faults resulted by varioustectonic effects related to the activity of the Dead Sea FaultsSystem (DSFS) in the region
From a hydrogeological point of view the Cenomanian-Turonian limestone and dolomite formations constitute themain groundwater aquifer in the area The general structureof these aquifer rocks is characterized by high groundwaterpermeability as a result of the fractured and karstified rocksat various depths This aquifer is regarded as the principlesource for several springs distributed through the regionBesides most of the local wells drilled in the Cenomanian-Turonian aquifer are characterized by high productivity TheQuaternary alluvial deposits which are basically composedof sands clays and gravels represent the second groundwateraquifer in the area This aquifer is porous and the groundwa-ter level is ranging between 185 and 200m (asl) Generallythe direction of the groundwater flow is from south to northcoinciding with the riversrsquo flow direction in the region Bothaquifers are fed by direct recharge throughhigh rate of rainfall(700ndash1000mmy) and drainage networks which are quitecommon in the area
3 Methodology and Instrumentation
Electrical Resistivity Tomography (ERT) has been widelyimplemented in the last few years especially in hydrogeologyand environmental issues [21ndash24]This techniquewas appliedin Abu Baara site to acquire a comprehensive image of thesubstructure of the damrsquos reservoir in order to characterizethe leakage problem For this reason two straight ERTprofiles were carried out in up- and downstream sidesparallel and close to the damrsquos embankment (Figure 3) Thefirst ERT profile (ERT-P1) is 715m in length with 5m as
an interelectrodes spacing and the second ERT profile (ERT-P2) is 430m in length with 2m as an interelectrodes spacingThe two profiles were measured during summer season asthe damrsquos lake was completely dry and empty of water TheERT measurements were conducted using Syscal Switch-72 developed by the French IRIS Instrument This newinstrumentation is equipped with a control unit to execute2D geoelectrical resistivity sections (multielectrodes) besidestraditional geoelectrical soundings (VES Wenner and SP)The instrument is composed of a central unit encompass-ing current transmission unit and potential reception unit(transmitter and receiver units are included in one box) inaddition to four special bobbinsmultiple switches that enableconnecting 72 stainless steel electrodes at once to carry outfield measurements
For executing the ERT profile 72 electrodes are plantedand arranged in straight pattern along the measurementsprofileThemeasuring operation is performed on the basis ofspecial mathematical sequence prepared in advance accord-ing to the objective of the measurements The sequence isbuilt using special software that enables the configurationand interval between the electrodes to be preselected Conse-quently the investigation depth and configuration of themea-surement can be determinedThe collected data are automati-cally stored in the instrumentrsquos memory using Schlumberger-Wenner sequence with an interelectrodes spacing of 2 and5m Thereby the investigation depth in this case rangesbetween 20 and 45m including 759 measuring points dis-tributed at 16 depth levels In order to perform a longERT profile it is necessary to adopt and use several Roll-Along Sequences compatible with the standard sequence thatshould be consistent in terms of configuration and electrodesinterval The Roll-Along Sequence of 36 electrodes includes304 additional measuring points Finally the stored raw dataare transported to PC for treatment and interpretation using2D inversion software The coordinates of profile points weredetermined using GPS with UTM projection A topographicsurvey has been also conducted along the ERT profile length
4 Results
The obtained results based on 2D inversion of the ERT fielddata were interpreted in order to characterize the subsurfacestructure within the penetrated investigation depthThe ERTprofiles were carried out 10 meters away from the damrsquosbody at up- and downstream sides The two profiles startfrom the damrsquos embankment southwestern edge towards thenortheastern end (Figure 3) The collected ERT data wereinverted using the least-squaresmethod including smoothingof model resistivity to obtain better results from noisy dataThe optimization of this method essentially depends onreducing the difference between the measured and calculatedapparent resistivity valuesThis difference is expressed by rootmean squared (RMS) error
The ERT field data were collected along ERP-P1 and ERT-P2 profilesThe data were inverted using RES2DINV softwaredeveloped by Loke and Barker in 1996 [25] Figures 4 and 6
4 International Journal of Geophysics
Spillway
Outlet control tunnel
Maarin village
Dam characteristics
Elevation of dam crest 2345 (asl)Maximum thickness 245 m
Dam lake surface 100 haMaximum storage 76 Mm3
Dam length 720 m
0 100 200
(m)
ERT-P2
ERT-P1
Dam body
Dam lake
Pz(1)
Pz(2)
N
Figure 3 Locations of the ERT profiles realized at up- and downstream sides of Abu Baara dam Pz(1) and Pz(2) piezometric boreholeslocated behind the dam body
show the complete set of the geoelectrical images of the mea-sured and the calculated apparent resistivity pseudosectionsas well as the inverted resistivity model of the ERT profilesThe geoelectrical ERT-P1 section includes a thin layer ofalluvial deposits which covers the first third of the sectionThe center part of the section is completely composed of thealluvial deposits to more than 45m depth At the last thirdof the section the thickness of this layer gradually decreasesuntil the end of the section The alluvial deposits overly hardand fractured limestones rocks which constitute the bedrockof the dam reservoir floor Several abnormal features suchas cavities voids and fractures were identified along theERT section within the limestone bedrock These featurescould be considered as anomalous structures that almostplay a significant role in the leakage processes from the damreservoir The ERT-P2 profile was conducted in upstreamside of the embankment of the dam The start point of thisERT-P2 profile is located at 20m before the beginning of theERT-P1 as illustrated in Figure 2 The difference between thestart points of the two profiles is related to the accessibilityand possibility of performing the field measurements Thegeneral structure of the ERT-P2 section seems to be similarto the previous ERT-P1 section from where it includes asuperficial layer of alluvial deposits and cover hard fracturedlimestones layer The depth of this section is about 20m dueto the 2m interelectrodes separation used This profile wasimplemented in order to obtain more details of substructuresbehind the dam body The resistivity values of the variousgeological structures and anomalies features which havebeen detected by the ERT sections are shown in Table 1
5 Interpretation of ERT Sections
The inverted resistivity model represents the subsurfaceresistivity values of the geological formations of the damrsquos lakefloor close to the dam body The results obtained which arebased on the 2D inversion of the field data were interpretedto characterize the shallow bedrock and other subsurfacefeatures in the site with the aid of the available lithologicalboreholes information
51 ERT-P1 Figure 4 illustrates the geoelectrical ERT-P1section which can be divided into three main blocks hori-zontally differentiated as follows
Block I This block extends from the beginning of the ERT-P1profile to a distance of 300m of the section It is composedof a 7m thick surficial layer in average with resistivityvalues ranging between 50 and 150Ωsdotm corresponding withQuaternary alluviumof clays sands and gravels covering thedamrsquos lake floor The alluvial deposits overlay gently dipping(5ndash7∘ valley-inward) Cenomanian-Turonian hard fracturedlimestone rocks These rocks which are characterized byhigh resistivity values varying between 300 and 1000Ωsdotmconstitute the main shallow bedrock of the damrsquos lake Adistinctive resistivity anomaly has been recognized withina distance interval of 60ndash90m measured from the ERT-P1section start point This anomaly is distinguished by highelectrical resistivity values exceeding 1200Ωsdotm It is believedthat this anomaly almost is attributed to a karstic cavitydeveloped within the limestone rocks by the influence of
International Journal of Geophysics 5
00 800 1600 2400 3200 4000 4800 560 640
260
853
162
239
316
382
459
PsZ
(m)S-W N-E
Measured apparent resistivity pseudosection
(a)
260
853
162
239
316
382
459
PsZ
00 800 1600 2400 3200 4000 4800 560 640
(m)
Calculated apparent resistivity pseudosection
(b)
F Discontinuity featurePz(1)
Pz(2)
F
Elev
atio
n (m
)
Probable cavity
Vertical clayey anomaly
Void filled by alluvial deposits
Calcareous bedrockCalcareous bedrockAlluvial deposits
Silt and sandy clays
Alluvial deposits
Limestonebedrock deposits
Probablecavity
Main valley00800 160
240320 400
4 80 560 640
First electrode is located at 00 mLast electrode is located at 7150 mUnit electrode spacing = 500 m
240
230
220
210
200
190
180
170
Model resistivity with topographyElevation iteration 5 RMS error = 72
749 156 324 674 140 292 607 1264
Resistivity (ohmmiddotm)
(c)
Figure 4 Interpretation of the geoelectrical section of the ERT-P1 profile carried out in downstream of Abu Baara dam (a) pseudosection ofthe measured apparent resistivity (b) pseudosection of the calculated apparent resistivity and (c) interpretation of the inverted ERT sectionwith topography Pz(1) and Pz(2) piezometric boreholes locations drilled behind the dam body
the groundwater flow in the area The presence of a karsticcavity near the surface and close to the dam body certainlyrepresents a suitable pathway for water leakage especiallywhen it has lateral and vertical extensions and when thestored water goes up to high levels (more than 220m asl)On the other hand the appearance of a cavity close to thedam body apparently poses a threat to the safety and stabilityof the dam Another anomalous feature is observed withina distance interval of 230ndash250m measured from the ERT-P1profile start point This feature is likely to be attributed toan open void filled by moderate resistivity alluvial depositsvalues (less than 150Ωsdotm)This void could result by the effectof karstification processes or dissolution of the carbonatesrocks Furthermore the geological description of these blockrocks is compatible with the lithological borehole log Pz(1)drilled upstream the dam (Figure 5) whose lithologicalcolumn is completely composed of hard fractured limestonesConsequently most of the detected features within thisblock form favorable zones for water leakage from the damrsquosreservoir
Table 1 Resistivities values of the detected subsurface featuresderived from the interpreted ERT sections
Number Structures and features ResistivityΩsdotm1 Silty and sandy clays 5ndash302 Alluvium and gravels deposits 50ndash1503 Limestones and dolomites bedrock 300ndash10004 Cavity 1000ndash13005 Void filled by alluvial deposits 50ndash1506 Vertical clayey anomaly 5ndash157 Fractures (discontinuity feature) mdash
Block II This block forms the central part of the ERT-P1profile coinciding with the main valley course and stretchingover a distance interval of 300 to 500m measured fromthe ERT section start point (Figure 4) The 200m longblock is sharply limited by two abrupt vertical edges likelyinterpreted as faults or fractures that resulted by tectonic
6 International Journal of Geophysics
200
24
475
62
87
12
Clay
Clay
200
90
525
150
Pz(1) borehole Litho
column Litho
columnLithological description
60
Depth (m)
Depth (m) Lithological description
Pz(2) borehole
Sandy clayey limestoneswith calcareous gravels
(filters)(filters)
Sandy clayey limestoneswith calcareous gravels
Hard fractured limestoneswith fine fissures
Soft chalky limestones
Hard fractured limestoneswith fine fissures
Hard fractured limestones
Sandy clay with gravels
Sandy clay with gravels
Sandy clay with gravels
Figure 5 Comparison between lithological logs of the boreholes Pz(1) and Pz(2) drilled directly behind the dam body modified after [20]
activity responsible for faulting and subsiding From geo-logical and tectonic point of view block II forms a 200mwide small graben structure coinciding with the main AbuBaara valley The structure is filled later by Quaternaryalluvium sediments whose electrical resistivity values rangebetween 50 and 150Ωsdotm and thickness likely exceeds the50m preset investigation depth On the other hand thelithological section of this block is corresponding to a largeextent with the lithological borehole column Pz(2) whichis composed completely of clays and sandy clays (Figure 5)The comparison between the Pz(1) lithological columncompletely composed of hard fractured limestones and thePz(2) column completely composed of sandy clays and thesharp contact between blocks (I) and (II) indicate stronglythe presence of a fault contact between them controlling theAbu Baara valley course Moreover a 20m wide wedge-like
anomaly is also recognized in ERT-P1 image adjacent to theblock II left edgeThis anomaly is interpreted as an abnormalvertical wedge filled by clays It could probably result byvertical water movement downcutting through the karsticlimestone Accordingly it is quite clear that this block isconsidered as the most important and significant segment ofthe ERT-P1 section since infiltration and water losses mostlikely occur along the faulted contact zones between alluviumand hard limestone
Block III It extends over the last 500ndash715m distance intervalof the ERT-P1 section Quaternary alluvium thickness layerincreases the valley inward to exceed 25m and its resistivityvalues as mentioned above vary between 50 and 150ΩsdotmThe alluvial deposits cover hard limestone rocks with high-resistivity (300ndash1000Ωsdotm) which are dipping 20∘ towards
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
2 International Journal of Geophysics
Palmyra
Damascus
HomsHamah
Tartus
Latakia
AleppoAr-Raqqa
Dayr Az-Zawr
Al-Hasakeh
Beirut
Turkey
Jordan
Iraq
Abo Kamal
Med
iterr
anea
n Se
aLe
bano
n
Syria
Iskenderun
Ephemeral stream
(km)
Abu Baara stream
Faults (existence and position) Upper Quaternary clays loams and pebblesPliocene clays marls limestonessandstones and conglomeratesCenomanian-Turonianlimestones and dolomites
0 2
Maarin
Abu Baaradam
N
cN2
cN2
Cr2cm-t
4
3699840099840030
99840036
99840099840022
998400
3599840099840006998400
3599840099840010998400
3599840099840013998400
Darrsquoa
Study area
Q3
Figure 1 Geological map of the study area showing the location of Abu Baara dam modified from [19]
NW SE
Borehole location
23452317
210 m (asl)1
4
2
3
4
1
5
Figure 2 Cross-section in Abu Baara earth dam body with (1) clay core (2 and 3) filters (4) support rockfill and (5) water reservoir
main axis and revealed the presence of some karstic cavesat depth [15] Hence the faulted area was delineated andsealed by a several meters thick clayey layer covering an areaof 16000m2 approximately Nevertheless the water seepageproblem from the damrsquos lake remained unsolved especiallywhen water level rises high in the reservoir Therefore thisproblem may affect the stability and the safety of dam in
the future Accordingly this work was proposed with theobjective of outlining the subsurface structure of Abu Baaradamrsquos reservoir delineating weak zones responsible for waterseepage and understanding deeply the origin of leakageproblem through applying a new developed geophysicaltechnique represented by Electrical Resistivity Tomography(ERT) method close to the damrsquos embankment downstream
International Journal of Geophysics 3
2 Geological and Hydrogeological Settings
Abu Baara dam is located at the extreme southern marginsof Al-Ghab pull-apart basin developed through the ongoingtectonic evolution of the Dead Sea Fault System (DSFS) innorthwestern Syria [16ndash18] The depression of Al-Ghab basinis filled with more than 100m thick Neogene and Quaternarylacustrine and alluvium deposits overlaying uncomfortablydeeply seated Cretaceous limestone [19]
As to local geological setting at Abu Baara dam site thedamrsquos lake floor is composed mainly of Quaternary alluviumclays sands and gravels (Q
3) in addition to carbonate-
siliceous cemented conglomerates (Figure 1) The thicknessof these deposits varies from one to tens of meters insome places The alluvial deposits overlay the Cenomanian-Turonian limestones and dolomites rocks (Cr
2cm-t) that
constitute the bedrock of the damrsquos reservoir These rockswhich are dipping towards the main stream by about 5ndash15 degrees are characterized by extensive fracturing andkarstification which contribute to forming cavities voidsand underground karstic conduits In addition the initialgeological investigations carried out by the Syrian GeneralCompany for Hydraulic Studies revealed the existence ofkarstified zones developed at various depths within thecalcareous rocks in the area On the other hand tectonicdisturbances such as faults of different trends are marked thecarbonates rocks in the region these faults resulted by varioustectonic effects related to the activity of the Dead Sea FaultsSystem (DSFS) in the region
From a hydrogeological point of view the Cenomanian-Turonian limestone and dolomite formations constitute themain groundwater aquifer in the area The general structureof these aquifer rocks is characterized by high groundwaterpermeability as a result of the fractured and karstified rocksat various depths This aquifer is regarded as the principlesource for several springs distributed through the regionBesides most of the local wells drilled in the Cenomanian-Turonian aquifer are characterized by high productivity TheQuaternary alluvial deposits which are basically composedof sands clays and gravels represent the second groundwateraquifer in the area This aquifer is porous and the groundwa-ter level is ranging between 185 and 200m (asl) Generallythe direction of the groundwater flow is from south to northcoinciding with the riversrsquo flow direction in the region Bothaquifers are fed by direct recharge throughhigh rate of rainfall(700ndash1000mmy) and drainage networks which are quitecommon in the area
3 Methodology and Instrumentation
Electrical Resistivity Tomography (ERT) has been widelyimplemented in the last few years especially in hydrogeologyand environmental issues [21ndash24]This techniquewas appliedin Abu Baara site to acquire a comprehensive image of thesubstructure of the damrsquos reservoir in order to characterizethe leakage problem For this reason two straight ERTprofiles were carried out in up- and downstream sidesparallel and close to the damrsquos embankment (Figure 3) Thefirst ERT profile (ERT-P1) is 715m in length with 5m as
an interelectrodes spacing and the second ERT profile (ERT-P2) is 430m in length with 2m as an interelectrodes spacingThe two profiles were measured during summer season asthe damrsquos lake was completely dry and empty of water TheERT measurements were conducted using Syscal Switch-72 developed by the French IRIS Instrument This newinstrumentation is equipped with a control unit to execute2D geoelectrical resistivity sections (multielectrodes) besidestraditional geoelectrical soundings (VES Wenner and SP)The instrument is composed of a central unit encompass-ing current transmission unit and potential reception unit(transmitter and receiver units are included in one box) inaddition to four special bobbinsmultiple switches that enableconnecting 72 stainless steel electrodes at once to carry outfield measurements
For executing the ERT profile 72 electrodes are plantedand arranged in straight pattern along the measurementsprofileThemeasuring operation is performed on the basis ofspecial mathematical sequence prepared in advance accord-ing to the objective of the measurements The sequence isbuilt using special software that enables the configurationand interval between the electrodes to be preselected Conse-quently the investigation depth and configuration of themea-surement can be determinedThe collected data are automati-cally stored in the instrumentrsquos memory using Schlumberger-Wenner sequence with an interelectrodes spacing of 2 and5m Thereby the investigation depth in this case rangesbetween 20 and 45m including 759 measuring points dis-tributed at 16 depth levels In order to perform a longERT profile it is necessary to adopt and use several Roll-Along Sequences compatible with the standard sequence thatshould be consistent in terms of configuration and electrodesinterval The Roll-Along Sequence of 36 electrodes includes304 additional measuring points Finally the stored raw dataare transported to PC for treatment and interpretation using2D inversion software The coordinates of profile points weredetermined using GPS with UTM projection A topographicsurvey has been also conducted along the ERT profile length
4 Results
The obtained results based on 2D inversion of the ERT fielddata were interpreted in order to characterize the subsurfacestructure within the penetrated investigation depthThe ERTprofiles were carried out 10 meters away from the damrsquosbody at up- and downstream sides The two profiles startfrom the damrsquos embankment southwestern edge towards thenortheastern end (Figure 3) The collected ERT data wereinverted using the least-squaresmethod including smoothingof model resistivity to obtain better results from noisy dataThe optimization of this method essentially depends onreducing the difference between the measured and calculatedapparent resistivity valuesThis difference is expressed by rootmean squared (RMS) error
The ERT field data were collected along ERP-P1 and ERT-P2 profilesThe data were inverted using RES2DINV softwaredeveloped by Loke and Barker in 1996 [25] Figures 4 and 6
4 International Journal of Geophysics
Spillway
Outlet control tunnel
Maarin village
Dam characteristics
Elevation of dam crest 2345 (asl)Maximum thickness 245 m
Dam lake surface 100 haMaximum storage 76 Mm3
Dam length 720 m
0 100 200
(m)
ERT-P2
ERT-P1
Dam body
Dam lake
Pz(1)
Pz(2)
N
Figure 3 Locations of the ERT profiles realized at up- and downstream sides of Abu Baara dam Pz(1) and Pz(2) piezometric boreholeslocated behind the dam body
show the complete set of the geoelectrical images of the mea-sured and the calculated apparent resistivity pseudosectionsas well as the inverted resistivity model of the ERT profilesThe geoelectrical ERT-P1 section includes a thin layer ofalluvial deposits which covers the first third of the sectionThe center part of the section is completely composed of thealluvial deposits to more than 45m depth At the last thirdof the section the thickness of this layer gradually decreasesuntil the end of the section The alluvial deposits overly hardand fractured limestones rocks which constitute the bedrockof the dam reservoir floor Several abnormal features suchas cavities voids and fractures were identified along theERT section within the limestone bedrock These featurescould be considered as anomalous structures that almostplay a significant role in the leakage processes from the damreservoir The ERT-P2 profile was conducted in upstreamside of the embankment of the dam The start point of thisERT-P2 profile is located at 20m before the beginning of theERT-P1 as illustrated in Figure 2 The difference between thestart points of the two profiles is related to the accessibilityand possibility of performing the field measurements Thegeneral structure of the ERT-P2 section seems to be similarto the previous ERT-P1 section from where it includes asuperficial layer of alluvial deposits and cover hard fracturedlimestones layer The depth of this section is about 20m dueto the 2m interelectrodes separation used This profile wasimplemented in order to obtain more details of substructuresbehind the dam body The resistivity values of the variousgeological structures and anomalies features which havebeen detected by the ERT sections are shown in Table 1
5 Interpretation of ERT Sections
The inverted resistivity model represents the subsurfaceresistivity values of the geological formations of the damrsquos lakefloor close to the dam body The results obtained which arebased on the 2D inversion of the field data were interpretedto characterize the shallow bedrock and other subsurfacefeatures in the site with the aid of the available lithologicalboreholes information
51 ERT-P1 Figure 4 illustrates the geoelectrical ERT-P1section which can be divided into three main blocks hori-zontally differentiated as follows
Block I This block extends from the beginning of the ERT-P1profile to a distance of 300m of the section It is composedof a 7m thick surficial layer in average with resistivityvalues ranging between 50 and 150Ωsdotm corresponding withQuaternary alluviumof clays sands and gravels covering thedamrsquos lake floor The alluvial deposits overlay gently dipping(5ndash7∘ valley-inward) Cenomanian-Turonian hard fracturedlimestone rocks These rocks which are characterized byhigh resistivity values varying between 300 and 1000Ωsdotmconstitute the main shallow bedrock of the damrsquos lake Adistinctive resistivity anomaly has been recognized withina distance interval of 60ndash90m measured from the ERT-P1section start point This anomaly is distinguished by highelectrical resistivity values exceeding 1200Ωsdotm It is believedthat this anomaly almost is attributed to a karstic cavitydeveloped within the limestone rocks by the influence of
International Journal of Geophysics 5
00 800 1600 2400 3200 4000 4800 560 640
260
853
162
239
316
382
459
PsZ
(m)S-W N-E
Measured apparent resistivity pseudosection
(a)
260
853
162
239
316
382
459
PsZ
00 800 1600 2400 3200 4000 4800 560 640
(m)
Calculated apparent resistivity pseudosection
(b)
F Discontinuity featurePz(1)
Pz(2)
F
Elev
atio
n (m
)
Probable cavity
Vertical clayey anomaly
Void filled by alluvial deposits
Calcareous bedrockCalcareous bedrockAlluvial deposits
Silt and sandy clays
Alluvial deposits
Limestonebedrock deposits
Probablecavity
Main valley00800 160
240320 400
4 80 560 640
First electrode is located at 00 mLast electrode is located at 7150 mUnit electrode spacing = 500 m
240
230
220
210
200
190
180
170
Model resistivity with topographyElevation iteration 5 RMS error = 72
749 156 324 674 140 292 607 1264
Resistivity (ohmmiddotm)
(c)
Figure 4 Interpretation of the geoelectrical section of the ERT-P1 profile carried out in downstream of Abu Baara dam (a) pseudosection ofthe measured apparent resistivity (b) pseudosection of the calculated apparent resistivity and (c) interpretation of the inverted ERT sectionwith topography Pz(1) and Pz(2) piezometric boreholes locations drilled behind the dam body
the groundwater flow in the area The presence of a karsticcavity near the surface and close to the dam body certainlyrepresents a suitable pathway for water leakage especiallywhen it has lateral and vertical extensions and when thestored water goes up to high levels (more than 220m asl)On the other hand the appearance of a cavity close to thedam body apparently poses a threat to the safety and stabilityof the dam Another anomalous feature is observed withina distance interval of 230ndash250m measured from the ERT-P1profile start point This feature is likely to be attributed toan open void filled by moderate resistivity alluvial depositsvalues (less than 150Ωsdotm)This void could result by the effectof karstification processes or dissolution of the carbonatesrocks Furthermore the geological description of these blockrocks is compatible with the lithological borehole log Pz(1)drilled upstream the dam (Figure 5) whose lithologicalcolumn is completely composed of hard fractured limestonesConsequently most of the detected features within thisblock form favorable zones for water leakage from the damrsquosreservoir
Table 1 Resistivities values of the detected subsurface featuresderived from the interpreted ERT sections
Number Structures and features ResistivityΩsdotm1 Silty and sandy clays 5ndash302 Alluvium and gravels deposits 50ndash1503 Limestones and dolomites bedrock 300ndash10004 Cavity 1000ndash13005 Void filled by alluvial deposits 50ndash1506 Vertical clayey anomaly 5ndash157 Fractures (discontinuity feature) mdash
Block II This block forms the central part of the ERT-P1profile coinciding with the main valley course and stretchingover a distance interval of 300 to 500m measured fromthe ERT section start point (Figure 4) The 200m longblock is sharply limited by two abrupt vertical edges likelyinterpreted as faults or fractures that resulted by tectonic
6 International Journal of Geophysics
200
24
475
62
87
12
Clay
Clay
200
90
525
150
Pz(1) borehole Litho
column Litho
columnLithological description
60
Depth (m)
Depth (m) Lithological description
Pz(2) borehole
Sandy clayey limestoneswith calcareous gravels
(filters)(filters)
Sandy clayey limestoneswith calcareous gravels
Hard fractured limestoneswith fine fissures
Soft chalky limestones
Hard fractured limestoneswith fine fissures
Hard fractured limestones
Sandy clay with gravels
Sandy clay with gravels
Sandy clay with gravels
Figure 5 Comparison between lithological logs of the boreholes Pz(1) and Pz(2) drilled directly behind the dam body modified after [20]
activity responsible for faulting and subsiding From geo-logical and tectonic point of view block II forms a 200mwide small graben structure coinciding with the main AbuBaara valley The structure is filled later by Quaternaryalluvium sediments whose electrical resistivity values rangebetween 50 and 150Ωsdotm and thickness likely exceeds the50m preset investigation depth On the other hand thelithological section of this block is corresponding to a largeextent with the lithological borehole column Pz(2) whichis composed completely of clays and sandy clays (Figure 5)The comparison between the Pz(1) lithological columncompletely composed of hard fractured limestones and thePz(2) column completely composed of sandy clays and thesharp contact between blocks (I) and (II) indicate stronglythe presence of a fault contact between them controlling theAbu Baara valley course Moreover a 20m wide wedge-like
anomaly is also recognized in ERT-P1 image adjacent to theblock II left edgeThis anomaly is interpreted as an abnormalvertical wedge filled by clays It could probably result byvertical water movement downcutting through the karsticlimestone Accordingly it is quite clear that this block isconsidered as the most important and significant segment ofthe ERT-P1 section since infiltration and water losses mostlikely occur along the faulted contact zones between alluviumand hard limestone
Block III It extends over the last 500ndash715m distance intervalof the ERT-P1 section Quaternary alluvium thickness layerincreases the valley inward to exceed 25m and its resistivityvalues as mentioned above vary between 50 and 150ΩsdotmThe alluvial deposits cover hard limestone rocks with high-resistivity (300ndash1000Ωsdotm) which are dipping 20∘ towards
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
International Journal of Geophysics 3
2 Geological and Hydrogeological Settings
Abu Baara dam is located at the extreme southern marginsof Al-Ghab pull-apart basin developed through the ongoingtectonic evolution of the Dead Sea Fault System (DSFS) innorthwestern Syria [16ndash18] The depression of Al-Ghab basinis filled with more than 100m thick Neogene and Quaternarylacustrine and alluvium deposits overlaying uncomfortablydeeply seated Cretaceous limestone [19]
As to local geological setting at Abu Baara dam site thedamrsquos lake floor is composed mainly of Quaternary alluviumclays sands and gravels (Q
3) in addition to carbonate-
siliceous cemented conglomerates (Figure 1) The thicknessof these deposits varies from one to tens of meters insome places The alluvial deposits overlay the Cenomanian-Turonian limestones and dolomites rocks (Cr
2cm-t) that
constitute the bedrock of the damrsquos reservoir These rockswhich are dipping towards the main stream by about 5ndash15 degrees are characterized by extensive fracturing andkarstification which contribute to forming cavities voidsand underground karstic conduits In addition the initialgeological investigations carried out by the Syrian GeneralCompany for Hydraulic Studies revealed the existence ofkarstified zones developed at various depths within thecalcareous rocks in the area On the other hand tectonicdisturbances such as faults of different trends are marked thecarbonates rocks in the region these faults resulted by varioustectonic effects related to the activity of the Dead Sea FaultsSystem (DSFS) in the region
From a hydrogeological point of view the Cenomanian-Turonian limestone and dolomite formations constitute themain groundwater aquifer in the area The general structureof these aquifer rocks is characterized by high groundwaterpermeability as a result of the fractured and karstified rocksat various depths This aquifer is regarded as the principlesource for several springs distributed through the regionBesides most of the local wells drilled in the Cenomanian-Turonian aquifer are characterized by high productivity TheQuaternary alluvial deposits which are basically composedof sands clays and gravels represent the second groundwateraquifer in the area This aquifer is porous and the groundwa-ter level is ranging between 185 and 200m (asl) Generallythe direction of the groundwater flow is from south to northcoinciding with the riversrsquo flow direction in the region Bothaquifers are fed by direct recharge throughhigh rate of rainfall(700ndash1000mmy) and drainage networks which are quitecommon in the area
3 Methodology and Instrumentation
Electrical Resistivity Tomography (ERT) has been widelyimplemented in the last few years especially in hydrogeologyand environmental issues [21ndash24]This techniquewas appliedin Abu Baara site to acquire a comprehensive image of thesubstructure of the damrsquos reservoir in order to characterizethe leakage problem For this reason two straight ERTprofiles were carried out in up- and downstream sidesparallel and close to the damrsquos embankment (Figure 3) Thefirst ERT profile (ERT-P1) is 715m in length with 5m as
an interelectrodes spacing and the second ERT profile (ERT-P2) is 430m in length with 2m as an interelectrodes spacingThe two profiles were measured during summer season asthe damrsquos lake was completely dry and empty of water TheERT measurements were conducted using Syscal Switch-72 developed by the French IRIS Instrument This newinstrumentation is equipped with a control unit to execute2D geoelectrical resistivity sections (multielectrodes) besidestraditional geoelectrical soundings (VES Wenner and SP)The instrument is composed of a central unit encompass-ing current transmission unit and potential reception unit(transmitter and receiver units are included in one box) inaddition to four special bobbinsmultiple switches that enableconnecting 72 stainless steel electrodes at once to carry outfield measurements
For executing the ERT profile 72 electrodes are plantedand arranged in straight pattern along the measurementsprofileThemeasuring operation is performed on the basis ofspecial mathematical sequence prepared in advance accord-ing to the objective of the measurements The sequence isbuilt using special software that enables the configurationand interval between the electrodes to be preselected Conse-quently the investigation depth and configuration of themea-surement can be determinedThe collected data are automati-cally stored in the instrumentrsquos memory using Schlumberger-Wenner sequence with an interelectrodes spacing of 2 and5m Thereby the investigation depth in this case rangesbetween 20 and 45m including 759 measuring points dis-tributed at 16 depth levels In order to perform a longERT profile it is necessary to adopt and use several Roll-Along Sequences compatible with the standard sequence thatshould be consistent in terms of configuration and electrodesinterval The Roll-Along Sequence of 36 electrodes includes304 additional measuring points Finally the stored raw dataare transported to PC for treatment and interpretation using2D inversion software The coordinates of profile points weredetermined using GPS with UTM projection A topographicsurvey has been also conducted along the ERT profile length
4 Results
The obtained results based on 2D inversion of the ERT fielddata were interpreted in order to characterize the subsurfacestructure within the penetrated investigation depthThe ERTprofiles were carried out 10 meters away from the damrsquosbody at up- and downstream sides The two profiles startfrom the damrsquos embankment southwestern edge towards thenortheastern end (Figure 3) The collected ERT data wereinverted using the least-squaresmethod including smoothingof model resistivity to obtain better results from noisy dataThe optimization of this method essentially depends onreducing the difference between the measured and calculatedapparent resistivity valuesThis difference is expressed by rootmean squared (RMS) error
The ERT field data were collected along ERP-P1 and ERT-P2 profilesThe data were inverted using RES2DINV softwaredeveloped by Loke and Barker in 1996 [25] Figures 4 and 6
4 International Journal of Geophysics
Spillway
Outlet control tunnel
Maarin village
Dam characteristics
Elevation of dam crest 2345 (asl)Maximum thickness 245 m
Dam lake surface 100 haMaximum storage 76 Mm3
Dam length 720 m
0 100 200
(m)
ERT-P2
ERT-P1
Dam body
Dam lake
Pz(1)
Pz(2)
N
Figure 3 Locations of the ERT profiles realized at up- and downstream sides of Abu Baara dam Pz(1) and Pz(2) piezometric boreholeslocated behind the dam body
show the complete set of the geoelectrical images of the mea-sured and the calculated apparent resistivity pseudosectionsas well as the inverted resistivity model of the ERT profilesThe geoelectrical ERT-P1 section includes a thin layer ofalluvial deposits which covers the first third of the sectionThe center part of the section is completely composed of thealluvial deposits to more than 45m depth At the last thirdof the section the thickness of this layer gradually decreasesuntil the end of the section The alluvial deposits overly hardand fractured limestones rocks which constitute the bedrockof the dam reservoir floor Several abnormal features suchas cavities voids and fractures were identified along theERT section within the limestone bedrock These featurescould be considered as anomalous structures that almostplay a significant role in the leakage processes from the damreservoir The ERT-P2 profile was conducted in upstreamside of the embankment of the dam The start point of thisERT-P2 profile is located at 20m before the beginning of theERT-P1 as illustrated in Figure 2 The difference between thestart points of the two profiles is related to the accessibilityand possibility of performing the field measurements Thegeneral structure of the ERT-P2 section seems to be similarto the previous ERT-P1 section from where it includes asuperficial layer of alluvial deposits and cover hard fracturedlimestones layer The depth of this section is about 20m dueto the 2m interelectrodes separation used This profile wasimplemented in order to obtain more details of substructuresbehind the dam body The resistivity values of the variousgeological structures and anomalies features which havebeen detected by the ERT sections are shown in Table 1
5 Interpretation of ERT Sections
The inverted resistivity model represents the subsurfaceresistivity values of the geological formations of the damrsquos lakefloor close to the dam body The results obtained which arebased on the 2D inversion of the field data were interpretedto characterize the shallow bedrock and other subsurfacefeatures in the site with the aid of the available lithologicalboreholes information
51 ERT-P1 Figure 4 illustrates the geoelectrical ERT-P1section which can be divided into three main blocks hori-zontally differentiated as follows
Block I This block extends from the beginning of the ERT-P1profile to a distance of 300m of the section It is composedof a 7m thick surficial layer in average with resistivityvalues ranging between 50 and 150Ωsdotm corresponding withQuaternary alluviumof clays sands and gravels covering thedamrsquos lake floor The alluvial deposits overlay gently dipping(5ndash7∘ valley-inward) Cenomanian-Turonian hard fracturedlimestone rocks These rocks which are characterized byhigh resistivity values varying between 300 and 1000Ωsdotmconstitute the main shallow bedrock of the damrsquos lake Adistinctive resistivity anomaly has been recognized withina distance interval of 60ndash90m measured from the ERT-P1section start point This anomaly is distinguished by highelectrical resistivity values exceeding 1200Ωsdotm It is believedthat this anomaly almost is attributed to a karstic cavitydeveloped within the limestone rocks by the influence of
International Journal of Geophysics 5
00 800 1600 2400 3200 4000 4800 560 640
260
853
162
239
316
382
459
PsZ
(m)S-W N-E
Measured apparent resistivity pseudosection
(a)
260
853
162
239
316
382
459
PsZ
00 800 1600 2400 3200 4000 4800 560 640
(m)
Calculated apparent resistivity pseudosection
(b)
F Discontinuity featurePz(1)
Pz(2)
F
Elev
atio
n (m
)
Probable cavity
Vertical clayey anomaly
Void filled by alluvial deposits
Calcareous bedrockCalcareous bedrockAlluvial deposits
Silt and sandy clays
Alluvial deposits
Limestonebedrock deposits
Probablecavity
Main valley00800 160
240320 400
4 80 560 640
First electrode is located at 00 mLast electrode is located at 7150 mUnit electrode spacing = 500 m
240
230
220
210
200
190
180
170
Model resistivity with topographyElevation iteration 5 RMS error = 72
749 156 324 674 140 292 607 1264
Resistivity (ohmmiddotm)
(c)
Figure 4 Interpretation of the geoelectrical section of the ERT-P1 profile carried out in downstream of Abu Baara dam (a) pseudosection ofthe measured apparent resistivity (b) pseudosection of the calculated apparent resistivity and (c) interpretation of the inverted ERT sectionwith topography Pz(1) and Pz(2) piezometric boreholes locations drilled behind the dam body
the groundwater flow in the area The presence of a karsticcavity near the surface and close to the dam body certainlyrepresents a suitable pathway for water leakage especiallywhen it has lateral and vertical extensions and when thestored water goes up to high levels (more than 220m asl)On the other hand the appearance of a cavity close to thedam body apparently poses a threat to the safety and stabilityof the dam Another anomalous feature is observed withina distance interval of 230ndash250m measured from the ERT-P1profile start point This feature is likely to be attributed toan open void filled by moderate resistivity alluvial depositsvalues (less than 150Ωsdotm)This void could result by the effectof karstification processes or dissolution of the carbonatesrocks Furthermore the geological description of these blockrocks is compatible with the lithological borehole log Pz(1)drilled upstream the dam (Figure 5) whose lithologicalcolumn is completely composed of hard fractured limestonesConsequently most of the detected features within thisblock form favorable zones for water leakage from the damrsquosreservoir
Table 1 Resistivities values of the detected subsurface featuresderived from the interpreted ERT sections
Number Structures and features ResistivityΩsdotm1 Silty and sandy clays 5ndash302 Alluvium and gravels deposits 50ndash1503 Limestones and dolomites bedrock 300ndash10004 Cavity 1000ndash13005 Void filled by alluvial deposits 50ndash1506 Vertical clayey anomaly 5ndash157 Fractures (discontinuity feature) mdash
Block II This block forms the central part of the ERT-P1profile coinciding with the main valley course and stretchingover a distance interval of 300 to 500m measured fromthe ERT section start point (Figure 4) The 200m longblock is sharply limited by two abrupt vertical edges likelyinterpreted as faults or fractures that resulted by tectonic
6 International Journal of Geophysics
200
24
475
62
87
12
Clay
Clay
200
90
525
150
Pz(1) borehole Litho
column Litho
columnLithological description
60
Depth (m)
Depth (m) Lithological description
Pz(2) borehole
Sandy clayey limestoneswith calcareous gravels
(filters)(filters)
Sandy clayey limestoneswith calcareous gravels
Hard fractured limestoneswith fine fissures
Soft chalky limestones
Hard fractured limestoneswith fine fissures
Hard fractured limestones
Sandy clay with gravels
Sandy clay with gravels
Sandy clay with gravels
Figure 5 Comparison between lithological logs of the boreholes Pz(1) and Pz(2) drilled directly behind the dam body modified after [20]
activity responsible for faulting and subsiding From geo-logical and tectonic point of view block II forms a 200mwide small graben structure coinciding with the main AbuBaara valley The structure is filled later by Quaternaryalluvium sediments whose electrical resistivity values rangebetween 50 and 150Ωsdotm and thickness likely exceeds the50m preset investigation depth On the other hand thelithological section of this block is corresponding to a largeextent with the lithological borehole column Pz(2) whichis composed completely of clays and sandy clays (Figure 5)The comparison between the Pz(1) lithological columncompletely composed of hard fractured limestones and thePz(2) column completely composed of sandy clays and thesharp contact between blocks (I) and (II) indicate stronglythe presence of a fault contact between them controlling theAbu Baara valley course Moreover a 20m wide wedge-like
anomaly is also recognized in ERT-P1 image adjacent to theblock II left edgeThis anomaly is interpreted as an abnormalvertical wedge filled by clays It could probably result byvertical water movement downcutting through the karsticlimestone Accordingly it is quite clear that this block isconsidered as the most important and significant segment ofthe ERT-P1 section since infiltration and water losses mostlikely occur along the faulted contact zones between alluviumand hard limestone
Block III It extends over the last 500ndash715m distance intervalof the ERT-P1 section Quaternary alluvium thickness layerincreases the valley inward to exceed 25m and its resistivityvalues as mentioned above vary between 50 and 150ΩsdotmThe alluvial deposits cover hard limestone rocks with high-resistivity (300ndash1000Ωsdotm) which are dipping 20∘ towards
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
4 International Journal of Geophysics
Spillway
Outlet control tunnel
Maarin village
Dam characteristics
Elevation of dam crest 2345 (asl)Maximum thickness 245 m
Dam lake surface 100 haMaximum storage 76 Mm3
Dam length 720 m
0 100 200
(m)
ERT-P2
ERT-P1
Dam body
Dam lake
Pz(1)
Pz(2)
N
Figure 3 Locations of the ERT profiles realized at up- and downstream sides of Abu Baara dam Pz(1) and Pz(2) piezometric boreholeslocated behind the dam body
show the complete set of the geoelectrical images of the mea-sured and the calculated apparent resistivity pseudosectionsas well as the inverted resistivity model of the ERT profilesThe geoelectrical ERT-P1 section includes a thin layer ofalluvial deposits which covers the first third of the sectionThe center part of the section is completely composed of thealluvial deposits to more than 45m depth At the last thirdof the section the thickness of this layer gradually decreasesuntil the end of the section The alluvial deposits overly hardand fractured limestones rocks which constitute the bedrockof the dam reservoir floor Several abnormal features suchas cavities voids and fractures were identified along theERT section within the limestone bedrock These featurescould be considered as anomalous structures that almostplay a significant role in the leakage processes from the damreservoir The ERT-P2 profile was conducted in upstreamside of the embankment of the dam The start point of thisERT-P2 profile is located at 20m before the beginning of theERT-P1 as illustrated in Figure 2 The difference between thestart points of the two profiles is related to the accessibilityand possibility of performing the field measurements Thegeneral structure of the ERT-P2 section seems to be similarto the previous ERT-P1 section from where it includes asuperficial layer of alluvial deposits and cover hard fracturedlimestones layer The depth of this section is about 20m dueto the 2m interelectrodes separation used This profile wasimplemented in order to obtain more details of substructuresbehind the dam body The resistivity values of the variousgeological structures and anomalies features which havebeen detected by the ERT sections are shown in Table 1
5 Interpretation of ERT Sections
The inverted resistivity model represents the subsurfaceresistivity values of the geological formations of the damrsquos lakefloor close to the dam body The results obtained which arebased on the 2D inversion of the field data were interpretedto characterize the shallow bedrock and other subsurfacefeatures in the site with the aid of the available lithologicalboreholes information
51 ERT-P1 Figure 4 illustrates the geoelectrical ERT-P1section which can be divided into three main blocks hori-zontally differentiated as follows
Block I This block extends from the beginning of the ERT-P1profile to a distance of 300m of the section It is composedof a 7m thick surficial layer in average with resistivityvalues ranging between 50 and 150Ωsdotm corresponding withQuaternary alluviumof clays sands and gravels covering thedamrsquos lake floor The alluvial deposits overlay gently dipping(5ndash7∘ valley-inward) Cenomanian-Turonian hard fracturedlimestone rocks These rocks which are characterized byhigh resistivity values varying between 300 and 1000Ωsdotmconstitute the main shallow bedrock of the damrsquos lake Adistinctive resistivity anomaly has been recognized withina distance interval of 60ndash90m measured from the ERT-P1section start point This anomaly is distinguished by highelectrical resistivity values exceeding 1200Ωsdotm It is believedthat this anomaly almost is attributed to a karstic cavitydeveloped within the limestone rocks by the influence of
International Journal of Geophysics 5
00 800 1600 2400 3200 4000 4800 560 640
260
853
162
239
316
382
459
PsZ
(m)S-W N-E
Measured apparent resistivity pseudosection
(a)
260
853
162
239
316
382
459
PsZ
00 800 1600 2400 3200 4000 4800 560 640
(m)
Calculated apparent resistivity pseudosection
(b)
F Discontinuity featurePz(1)
Pz(2)
F
Elev
atio
n (m
)
Probable cavity
Vertical clayey anomaly
Void filled by alluvial deposits
Calcareous bedrockCalcareous bedrockAlluvial deposits
Silt and sandy clays
Alluvial deposits
Limestonebedrock deposits
Probablecavity
Main valley00800 160
240320 400
4 80 560 640
First electrode is located at 00 mLast electrode is located at 7150 mUnit electrode spacing = 500 m
240
230
220
210
200
190
180
170
Model resistivity with topographyElevation iteration 5 RMS error = 72
749 156 324 674 140 292 607 1264
Resistivity (ohmmiddotm)
(c)
Figure 4 Interpretation of the geoelectrical section of the ERT-P1 profile carried out in downstream of Abu Baara dam (a) pseudosection ofthe measured apparent resistivity (b) pseudosection of the calculated apparent resistivity and (c) interpretation of the inverted ERT sectionwith topography Pz(1) and Pz(2) piezometric boreholes locations drilled behind the dam body
the groundwater flow in the area The presence of a karsticcavity near the surface and close to the dam body certainlyrepresents a suitable pathway for water leakage especiallywhen it has lateral and vertical extensions and when thestored water goes up to high levels (more than 220m asl)On the other hand the appearance of a cavity close to thedam body apparently poses a threat to the safety and stabilityof the dam Another anomalous feature is observed withina distance interval of 230ndash250m measured from the ERT-P1profile start point This feature is likely to be attributed toan open void filled by moderate resistivity alluvial depositsvalues (less than 150Ωsdotm)This void could result by the effectof karstification processes or dissolution of the carbonatesrocks Furthermore the geological description of these blockrocks is compatible with the lithological borehole log Pz(1)drilled upstream the dam (Figure 5) whose lithologicalcolumn is completely composed of hard fractured limestonesConsequently most of the detected features within thisblock form favorable zones for water leakage from the damrsquosreservoir
Table 1 Resistivities values of the detected subsurface featuresderived from the interpreted ERT sections
Number Structures and features ResistivityΩsdotm1 Silty and sandy clays 5ndash302 Alluvium and gravels deposits 50ndash1503 Limestones and dolomites bedrock 300ndash10004 Cavity 1000ndash13005 Void filled by alluvial deposits 50ndash1506 Vertical clayey anomaly 5ndash157 Fractures (discontinuity feature) mdash
Block II This block forms the central part of the ERT-P1profile coinciding with the main valley course and stretchingover a distance interval of 300 to 500m measured fromthe ERT section start point (Figure 4) The 200m longblock is sharply limited by two abrupt vertical edges likelyinterpreted as faults or fractures that resulted by tectonic
6 International Journal of Geophysics
200
24
475
62
87
12
Clay
Clay
200
90
525
150
Pz(1) borehole Litho
column Litho
columnLithological description
60
Depth (m)
Depth (m) Lithological description
Pz(2) borehole
Sandy clayey limestoneswith calcareous gravels
(filters)(filters)
Sandy clayey limestoneswith calcareous gravels
Hard fractured limestoneswith fine fissures
Soft chalky limestones
Hard fractured limestoneswith fine fissures
Hard fractured limestones
Sandy clay with gravels
Sandy clay with gravels
Sandy clay with gravels
Figure 5 Comparison between lithological logs of the boreholes Pz(1) and Pz(2) drilled directly behind the dam body modified after [20]
activity responsible for faulting and subsiding From geo-logical and tectonic point of view block II forms a 200mwide small graben structure coinciding with the main AbuBaara valley The structure is filled later by Quaternaryalluvium sediments whose electrical resistivity values rangebetween 50 and 150Ωsdotm and thickness likely exceeds the50m preset investigation depth On the other hand thelithological section of this block is corresponding to a largeextent with the lithological borehole column Pz(2) whichis composed completely of clays and sandy clays (Figure 5)The comparison between the Pz(1) lithological columncompletely composed of hard fractured limestones and thePz(2) column completely composed of sandy clays and thesharp contact between blocks (I) and (II) indicate stronglythe presence of a fault contact between them controlling theAbu Baara valley course Moreover a 20m wide wedge-like
anomaly is also recognized in ERT-P1 image adjacent to theblock II left edgeThis anomaly is interpreted as an abnormalvertical wedge filled by clays It could probably result byvertical water movement downcutting through the karsticlimestone Accordingly it is quite clear that this block isconsidered as the most important and significant segment ofthe ERT-P1 section since infiltration and water losses mostlikely occur along the faulted contact zones between alluviumand hard limestone
Block III It extends over the last 500ndash715m distance intervalof the ERT-P1 section Quaternary alluvium thickness layerincreases the valley inward to exceed 25m and its resistivityvalues as mentioned above vary between 50 and 150ΩsdotmThe alluvial deposits cover hard limestone rocks with high-resistivity (300ndash1000Ωsdotm) which are dipping 20∘ towards
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Applied ampEnvironmentalSoil Science
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Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
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International Journal of
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OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
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MineralogyInternational Journal of
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MeteorologyAdvances in
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Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
International Journal of Geophysics 5
00 800 1600 2400 3200 4000 4800 560 640
260
853
162
239
316
382
459
PsZ
(m)S-W N-E
Measured apparent resistivity pseudosection
(a)
260
853
162
239
316
382
459
PsZ
00 800 1600 2400 3200 4000 4800 560 640
(m)
Calculated apparent resistivity pseudosection
(b)
F Discontinuity featurePz(1)
Pz(2)
F
Elev
atio
n (m
)
Probable cavity
Vertical clayey anomaly
Void filled by alluvial deposits
Calcareous bedrockCalcareous bedrockAlluvial deposits
Silt and sandy clays
Alluvial deposits
Limestonebedrock deposits
Probablecavity
Main valley00800 160
240320 400
4 80 560 640
First electrode is located at 00 mLast electrode is located at 7150 mUnit electrode spacing = 500 m
240
230
220
210
200
190
180
170
Model resistivity with topographyElevation iteration 5 RMS error = 72
749 156 324 674 140 292 607 1264
Resistivity (ohmmiddotm)
(c)
Figure 4 Interpretation of the geoelectrical section of the ERT-P1 profile carried out in downstream of Abu Baara dam (a) pseudosection ofthe measured apparent resistivity (b) pseudosection of the calculated apparent resistivity and (c) interpretation of the inverted ERT sectionwith topography Pz(1) and Pz(2) piezometric boreholes locations drilled behind the dam body
the groundwater flow in the area The presence of a karsticcavity near the surface and close to the dam body certainlyrepresents a suitable pathway for water leakage especiallywhen it has lateral and vertical extensions and when thestored water goes up to high levels (more than 220m asl)On the other hand the appearance of a cavity close to thedam body apparently poses a threat to the safety and stabilityof the dam Another anomalous feature is observed withina distance interval of 230ndash250m measured from the ERT-P1profile start point This feature is likely to be attributed toan open void filled by moderate resistivity alluvial depositsvalues (less than 150Ωsdotm)This void could result by the effectof karstification processes or dissolution of the carbonatesrocks Furthermore the geological description of these blockrocks is compatible with the lithological borehole log Pz(1)drilled upstream the dam (Figure 5) whose lithologicalcolumn is completely composed of hard fractured limestonesConsequently most of the detected features within thisblock form favorable zones for water leakage from the damrsquosreservoir
Table 1 Resistivities values of the detected subsurface featuresderived from the interpreted ERT sections
Number Structures and features ResistivityΩsdotm1 Silty and sandy clays 5ndash302 Alluvium and gravels deposits 50ndash1503 Limestones and dolomites bedrock 300ndash10004 Cavity 1000ndash13005 Void filled by alluvial deposits 50ndash1506 Vertical clayey anomaly 5ndash157 Fractures (discontinuity feature) mdash
Block II This block forms the central part of the ERT-P1profile coinciding with the main valley course and stretchingover a distance interval of 300 to 500m measured fromthe ERT section start point (Figure 4) The 200m longblock is sharply limited by two abrupt vertical edges likelyinterpreted as faults or fractures that resulted by tectonic
6 International Journal of Geophysics
200
24
475
62
87
12
Clay
Clay
200
90
525
150
Pz(1) borehole Litho
column Litho
columnLithological description
60
Depth (m)
Depth (m) Lithological description
Pz(2) borehole
Sandy clayey limestoneswith calcareous gravels
(filters)(filters)
Sandy clayey limestoneswith calcareous gravels
Hard fractured limestoneswith fine fissures
Soft chalky limestones
Hard fractured limestoneswith fine fissures
Hard fractured limestones
Sandy clay with gravels
Sandy clay with gravels
Sandy clay with gravels
Figure 5 Comparison between lithological logs of the boreholes Pz(1) and Pz(2) drilled directly behind the dam body modified after [20]
activity responsible for faulting and subsiding From geo-logical and tectonic point of view block II forms a 200mwide small graben structure coinciding with the main AbuBaara valley The structure is filled later by Quaternaryalluvium sediments whose electrical resistivity values rangebetween 50 and 150Ωsdotm and thickness likely exceeds the50m preset investigation depth On the other hand thelithological section of this block is corresponding to a largeextent with the lithological borehole column Pz(2) whichis composed completely of clays and sandy clays (Figure 5)The comparison between the Pz(1) lithological columncompletely composed of hard fractured limestones and thePz(2) column completely composed of sandy clays and thesharp contact between blocks (I) and (II) indicate stronglythe presence of a fault contact between them controlling theAbu Baara valley course Moreover a 20m wide wedge-like
anomaly is also recognized in ERT-P1 image adjacent to theblock II left edgeThis anomaly is interpreted as an abnormalvertical wedge filled by clays It could probably result byvertical water movement downcutting through the karsticlimestone Accordingly it is quite clear that this block isconsidered as the most important and significant segment ofthe ERT-P1 section since infiltration and water losses mostlikely occur along the faulted contact zones between alluviumand hard limestone
Block III It extends over the last 500ndash715m distance intervalof the ERT-P1 section Quaternary alluvium thickness layerincreases the valley inward to exceed 25m and its resistivityvalues as mentioned above vary between 50 and 150ΩsdotmThe alluvial deposits cover hard limestone rocks with high-resistivity (300ndash1000Ωsdotm) which are dipping 20∘ towards
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
6 International Journal of Geophysics
200
24
475
62
87
12
Clay
Clay
200
90
525
150
Pz(1) borehole Litho
column Litho
columnLithological description
60
Depth (m)
Depth (m) Lithological description
Pz(2) borehole
Sandy clayey limestoneswith calcareous gravels
(filters)(filters)
Sandy clayey limestoneswith calcareous gravels
Hard fractured limestoneswith fine fissures
Soft chalky limestones
Hard fractured limestoneswith fine fissures
Hard fractured limestones
Sandy clay with gravels
Sandy clay with gravels
Sandy clay with gravels
Figure 5 Comparison between lithological logs of the boreholes Pz(1) and Pz(2) drilled directly behind the dam body modified after [20]
activity responsible for faulting and subsiding From geo-logical and tectonic point of view block II forms a 200mwide small graben structure coinciding with the main AbuBaara valley The structure is filled later by Quaternaryalluvium sediments whose electrical resistivity values rangebetween 50 and 150Ωsdotm and thickness likely exceeds the50m preset investigation depth On the other hand thelithological section of this block is corresponding to a largeextent with the lithological borehole column Pz(2) whichis composed completely of clays and sandy clays (Figure 5)The comparison between the Pz(1) lithological columncompletely composed of hard fractured limestones and thePz(2) column completely composed of sandy clays and thesharp contact between blocks (I) and (II) indicate stronglythe presence of a fault contact between them controlling theAbu Baara valley course Moreover a 20m wide wedge-like
anomaly is also recognized in ERT-P1 image adjacent to theblock II left edgeThis anomaly is interpreted as an abnormalvertical wedge filled by clays It could probably result byvertical water movement downcutting through the karsticlimestone Accordingly it is quite clear that this block isconsidered as the most important and significant segment ofthe ERT-P1 section since infiltration and water losses mostlikely occur along the faulted contact zones between alluviumand hard limestone
Block III It extends over the last 500ndash715m distance intervalof the ERT-P1 section Quaternary alluvium thickness layerincreases the valley inward to exceed 25m and its resistivityvalues as mentioned above vary between 50 and 150ΩsdotmThe alluvial deposits cover hard limestone rocks with high-resistivity (300ndash1000Ωsdotm) which are dipping 20∘ towards
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
International Journal of Geophysics 7
FPz(1)
Vertical clayey anomaly
Probable cavity
Pz(2)
Alluvial deposits
Silt and sandyclays
Alluvial deposits
Limestonebedrock
Cavity
FF
Calcareous bedrock
Alluvial deposits
F fractures
Unit electrode spacing = 200 mFirst electrode is located at 00 mLast electrode is located at 4300 m
Elevation model resistivity with topographyIteration 5 RMS error = 60
Resistivity (ohmmiddotm)552 118 254 544 117 250 536 1149
240
235
230
220
225
210
215
205
200
190
195
00
320640
960128
160 192224 256
288
320 352 384416
Figure 6 Interpretation of the geoelectrical section of the ERT-P2 profile carried out in upstream of Abu Baara dam where Pz(1) and Pz(2)are piezometric boreholes
the main valley An abrupt discontinuity feature is observedclose to the end of the ERT section (at 650m distancemeasured from profile start eastward) corresponding witha vertical fracture in limestone It widens downwards and isfilled with low resistivity alluvial deposits The discontinuityfeature represents an additional probable factor for waterseepage from the damrsquos lake
52 ERT-P2 This profile is situated behind the dam bodyand extends along a distance of 430m Figure 6 illustratesthe inverted resistivity section of the ERT-P2 profile Thegeometry and general structure of the detected geologicalfeatures revealed by the geoelectrical ERT-P2 section aresimilar to what was found in the previous ERT-P1 sectionbut in more detail due to the use of 2m as interelectrodesspacing rather than 5m The alluvial deposits layer which iscomposed of clays sands and gravel covers the superficialparts of the profile and it seems to be irregular with regardto the thickness This is due to the irregularity of the erodedsurface of the underlying limestone bedrock The secondlayer is related to the hard and fractured limestone bedrock(300ndash1000Ωsdotm) which forms the basement of the dam lakeSeveral subvertical fractures could be identified along thisbedrock The cavity and the vertical clayey anomalies whichappeared in the previous ERT-P1 section are also presented inthe ERT-P2 section (Figures 5 and 6) This finding confirmsthe existence of these anomalous features in the subsurfacegeological structure near to the dam body Furthermore thepresence of these abnormal features in both ERT sectionsproves that these features have lateral extensions passingunderneath the dam embankment Additionally the appear-ance of the detected cavity in both sides of the dam indicatesclearly that it is most likely related to underground karsticconduit and this explains the sharp decreasing in water levelin the lake when it reaches levels more than 220m (asl)All these factors which include the eroded and fracturedbedrock cavities and fractures are certainly enhancing theleakage processes throughout the dam reservoir
Table 2 summarizes the interpretation of the ERT sectionsand describes the characteristics of the detected subsurfacefeatures and indicates the possible locations of water leakagefrom the damrsquos reservoir close to the embankment of the dam
6 Conclusion
The results obtained by the application of the ElectricalResistivity Tomography (ERT) confirm the ability of thistechnique to delineate some critical geological subsurfacestructures such as faults fractures cavities and discontinuityfeatures
The analysis of the ERT sections performed close tothe embankment in up- and downstream of Abu Baaradam revealed three main blocks horizontally differentiatedforming the subsurface structure of the damrsquos reservoir Thefirst and the third blocks consisted of an uppermost layercomposed of Quaternary alluvial deposits of clays sandsand gravels The alluvial deposits layer covers fractured andkarstified limestone rocks characterized by the presenceof cavities voids and tectonic discontinuities These rocksconstitute main subsurface bedrock of the dam lake floorwhereas the second block is bounded by two fracturesrepresenting the central subsiding block of a small grabendeveloped into Abu Baara main valley The lithologicalsubstructures revealed by the ERT sections are compati-ble with the lithological columns of the two piezometricboreholes drilled behind the dam body and confirm thepresence of faults or fractures which control Abu Baara mainvalley course Eventually it is evident that the fractured andkarstified limestone bedrock including cavities and fractureswhich underlay the reservoir is the main causative factorresponsible for the leakage in the Abu Baara dam
Conflict of Interests
The author declares that there is no conflict of interestsregarding the publication of this paper
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
8 International Journal of Geophysics
Table2Fu
lldescrip
tionof
thed
etectedsubsurface
features
deriv
edfro
mtheE
RT-P1surveyprofi
leatAb
uBa
arae
arth
dam
ERTprofi
leleng
th715m
Detectedlayers
thickn
ess(m)
Lithological
descrip
tion
Beddip
Resistiv
ityvalues
(Ωsdotm
)
Abno
rmalfeatures
Possibilityof
seepage
Kind
ofanom
aly
Locatio
non
ERTsection
Block(I)
0ndash300m
L11ndash5
Allu
vium
clays
sand
sandgravels
5ndash7∘
towardthe
valley
50ndash150
mdashmdash
mdash
L240ndash
45Limestonesa
nddo
lomitesrocks
gt1200
50ndash150
Cavity
Void
filledby
alluvium
60ndash9
0m230ndash
250m
Possibleseepage
Block(II)
300ndash
500m
L45
Allu
vium
clays
sand
sandgravels
0∘50ndash150
Subsidingstr
ucture
(mainvalley)
300ndash
500m
Seepagethrou
ghbo
thedges
5ndash15
Verticalcla
yey
zone
300ndash
320m
Possibleseepage
Block(III)
500ndash
715m
L11ndash25
Allu
vium
clays
sand
sandgravels
20∘towardthe
valley
50ndash150
mdashmdash
mdash
L230ndash
45Limestonesa
nddo
lomitesrocks
300ndash
1000
Disc
ontin
uity
feature
650m
Possibleseepage
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
International Journal of Geophysics 9
Acknowledgments
Theauthor would like to thank Professor I Othman DirectorGeneral of the Atomic Energy Commission of Syria (AECS)for his encouragement and constant supportThanks are alsodue toDr Z KattanHead of theGeologyDepartment and tothe authorrsquos colleaguesMAl-Hilal andY Radwan for readingand improving the paper Thanks also are due to Dr S Al-Diab and E Soliman for their help in the field
References
[1] S Johansson and T Dahlin ldquoSeepage monitoring in an earthembankment dam by repeated resistivity measurementsrdquo Euro-pean Journal of Environmental and Engineering Geophysics vol1 no 3 pp 229ndash247 1996
[2] T V Panthulu C Krishnaiah and J M Shirke ldquoDetection ofseepage paths in earth dams using self-potential and electricalresistivity methodsrdquo Engineering Geology vol 59 no 3-4 pp281ndash295 2001
[3] M A J Bakker D Maljers and H J T Weerts ldquoGround-penetrating radar profiling on embanked floodplainsrdquo Nether-lands Journal of Geosciences vol 86 no 1 pp 55ndash61 2007
[4] S Oh andC-G Sun ldquoCombined analysis of electrical resistivityand geotechnical SPT blow counts for the safety assessment offill damrdquo Environmental Geology vol 54 no 1 pp 31ndash42 2008
[5] P Sjodahl T Dahlin S Johansson andM H Loke ldquoResistivitymonitoring for leakage and internal erosion detection at Hallbyembankment damrdquo Journal of Applied Geophysics vol 65 no3-4 pp 155ndash164 2008
[6] J Asfahani Y Radwan and I Layyous ldquoIntegrated geophysicaland morphotectonic survey of the impact of Ghab extensionaltectonics on the Qastoon Dam Northwestern Syriardquo Pure andApplied Geophysics vol 167 no 3 pp 323ndash338 2010
[7] P A Bedrosian B L Burton M H Powers B J MinsleyJ D Phillips and L E Hunter ldquoGeophysical investigationsof geology and structure at the Martis Creek Dam TruckeeCaliforniardquo Journal of Applied Geophysics vol 77 pp 7ndash20 2012
[8] A Aina M O Olorunfemi and J S Ojo ldquoAn integrationof aeromagnetic and electrical resistivity methods in dam siteinvestigationrdquo Geophysics vol 61 no 2 pp 349ndash356 1996
[9] A T Batayneh A S Al Zoubi and A A Abueladas ldquoGeo-physical investigations for the location of a proposed dam inAl Bishriyya (Al Aritayn) area northeast Badia of JordanrdquoEnvironmental Geology vol 40 no 7 pp 918ndash922 2001
[10] I-K Cho and J-Y Yeom ldquoCrossline resistivity tomographyfor the delineation of anomalous seepage pathways in anembankment damrdquo Geophysics vol 72 no 2 pp G31ndashG382007
[11] I B Osazuwa and C E Chii ldquoA two-dimensional electricalresistivity imaging of an earth dam Zariardquo Nigeria Journal ofEnvironmental Hydrology vol 17 no 28 pp 1ndash8 2009
[12] W Al-Fares ldquoContribution of the geophysical methods incharacterizing the water leakage in Afamia B dam SyriardquoJournal of Applied Geophysics vol 75 no 3 pp 464ndash471 2011
[13] SThompson BKulessa andA Luckman ldquoIntegrated electricalresistivity tomography (ERT) and self-potential (SP) techniquesfor assessing hydrological processes within glacial lake morainedamsrdquo Journal of Glaciology vol 58 no 211 pp 849ndash858 2012
[14] A D Chinedu and A J Ogah ldquoElectrical resistivity imaging ofsuspected seepage channels in an earth dam in Zaria North-Western Nigeriardquo Open Journal of Applied Sciences vol 3 no 1pp 145ndash154 2013
[15] S Al-Diab ldquoReport of geophysical investigations executedunder the technical conditions proposed by EDF to estimate thetechnical situation of Abu Baara damrdquo Internal Report 2008
[16] G Brew Tectonic evolution of Syria interpreted from integratedgeophysical and geological analysis [PhD thesis] Cornell Uni-versity Ithaca NY USA 2001
[17] F Gomez M Khawlie C Tabet A N Darkal K Khair and MBarazangi ldquoLate Cenozoic uplift along the northern Dead Seatransform in Lebanon and Syriardquo Earth and Planetary ScienceLetters vol 241 no 3-4 pp 913ndash931 2006
[18] S Hamade and C Tabet ldquoThe impacts of climate change andhuman activities on water resources availability in the Oronteswatershed case of the Ghab region in Syriardquo Journal of WaterSustainability vol 3 no 1 pp 45ndash59 2013
[19] V Ponikarov The Geological Map of Syria Hama-LatheqiehSheet Scale 11200000 VO Technoexport Ministry of Indus-try Damascus Syria 1966
[20] General Company of Hydraulic Studies in Syria ldquoTechnicalreport about the geological and geophysical investigations inAbu Baara damrdquo Internal Report 2008
[21] W J Seaton and T J Burbey ldquoEvaluation of two-dimensionalresistivity methods in a fractured crystalline-rock terranerdquoJournal of Applied Geophysics vol 51 no 1 pp 21ndash41 2002
[22] S RWilson M Ingham and J A McConchie ldquoThe applicabil-ity of earth resistivity methods for saline interface definitionrdquoJournal of Hydrology vol 316 no 1ndash4 pp 301ndash312 2006
[23] M Lazzari A Loperte and A Perrone ldquoNear surface geo-physics techniques and geomorphological approach to recon-struct the hazard cave map in historical and urban areasrdquoAdvances in Geosciences vol 24 pp 35ndash44 2010
[24] J Zhu J C Currens and J S Dinger ldquoChallenges of usingelectrical resistivity method to locate karst conduitsmdasha fieldcase in the Inner Bluegrass Region Kentuckyrdquo Journal ofApplied Geophysics vol 75 no 3 pp 523ndash530 2011
[25] M H Loke and R D Barker ldquoRapid least-squares inver-sion of apparent resistivity pseudosections by a quasi-Newtonmethodrdquo Geophysical Prospecting vol 44 no 1 pp 131ndash1521996
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ClimatologyJournal of
EcologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
EarthquakesJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom
Applied ampEnvironmentalSoil Science
Volume 2014
Mining
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal of
Geophysics
OceanographyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal ofPetroleum Engineering
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
GeochemistryHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Atmospheric SciencesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OceanographyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MineralogyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MeteorologyAdvances in
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Paleontology JournalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geological ResearchJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Geology Advances in