32/ uu^ (3^-3 zre* ÇT A^ , ... Mi:-*.. , <V/ The hydrogeology of the northern part of the Western Desert in Egypt A.B. Pomper Report 34 The WINAND STARING CENTRE, Wageningen (TheNetherlands) , 1990 hm.mi lSn530£,lr\7Q^ 8f ABSTRACT Pomper, A.B.» 1990.Th e hydrogeology of the northern part of the Western Desert in Egypt. Wageningen,Th e Winand Staring Centre. Report 34» 75p. , 36figs , 5 tables. The investigations concerned fixing of the hydrogeological system of the area. With help of literature data, supplemented with own calculations and observations in the area, itappeare d that two aquifers occur in the subsoil with an aquitard in between.Th e latter only occurs in the northern part of the area, so in the remaining part only one -ope n -aquife r ispresent . For each of the aquifers the hydrological properties are calculated. In the northern part of the area salt water occurs in the subsoil, in the southern part fresh water.Th e salt water in the lower aquifer has extreme high salt concentrations (brines), in theuppe r aquifer mostly brackish water occurs.Th e fresh groundwater in the southern part originates from other climatic circumstances as the present, which among others was evident from stable isotope observations. Keywords! Hydrogeology, geology, Egypt,Wester n Desert, stable isotopes. ISSN 0924-3062 Copyright 1990 The WINAND STARING CENTRE for Integrated Land, Soil and Water Research, Postbus 125, 6700A C Wageningen (The Netherlands). Phonei +318370-74200,fa x +318370-24812, telex 75230VISI-NL . The WINAND STARING CENTRE iscontinuin g the research oft Institute for Land and WaterHangemen t Research (ICW), Institute for Pesticide Research, Environment Division (IOB),Dorschkam p Research Institute for Forestry and Landscape Planning,Divisio n of Landscape Planning (LB),an d Soil Survey Institute (STIBOKA) . No part of this publication may be reproduced of published in any form or by any means,o r stored in a data base or retrieval system, without the written permission from the Winand Staring Centre. Project 8370.3 95IS/12.90 CONTENTS Page PREFACE 9 SUMMARY 11 1 INTRODUCTION 15 2 GENERALDESCRIPTIO NO FTH EARE A 17 3 TECTONICSITUATIO N 19 4 GEOMORPHOLOGICALSETTIN G 23 5 GEOLOGICALFORMATION S 25 5.1 General 25 5.2 Formationsencountere d 25 5.2.1 Miocene 31 5.2.2 Oligocene/UpperEocen e 32 5.2.3 Eocene/Paleocene 34 5.2.4 Cretaceous 35 5.2.5 Cenomanian 37 5.2.6 LowerCretaceou s 38 5.2.7 Jurassic 41 5.2.8 Pre-Jurassicdeposit s 41 6 INTEGRATIONO FTH EGEOLOGICA LDAT AWIT HTH E HYDROLOGICALCONDITION S 43 6.1 Procedure inthi spape r formappin gth e transmissivities 44 6.2 Hydraulicconductivitie s 44 6.3 Theinfluenc eo ftemperatur ean dhig hsal t concentrations ongroundwate r flow 48 6.3.1 Temperature 48 6.3.2 Differences insal tconcentration s 50 6.4 Thema po fth etransmissivit yo fth eNubia n SandstoneComple x 50 6.5 Thetransmissivit y ofth edeposit so fth e MoghraFormatio n 52 7 THEHYDROCHEMICA LSITUATIO N 55 7.1 Watertypes 56 7.2 Observations 56 7.3 Chloride 61 7.4 Thestabl eisotope s 62 7.4.1 General 62 7.4.2 Theobservation s 63 7.5 Discussion 64 8 CONCLUSIONS 65 Page REFERENCES 67 APPENDICES 1 Wellnumber s 71 2 Chemicalanalyse s 75 FIGURES 1 Mapo fEgyp twit hlocatio no fth einvestigate d areaan dmai ntopographi cname s 16 2 Topographicalma po fEgyp t 17 3 Simplified tectonicma po fEgyp t 19 4 Tectonicma paccordin gt oIWACO/RIG W 20 5 Faultsi nth eoverlyin gdeposit so fth e Precambrianbasemen t inth eWester nDeser t 20 6 Locationma po fwell s 26 7 The thicknesso fth edeposit so fth eMiocen e 31 8 Schematic faciesprofil e 33 9 Mapshowin gth edistributio no ffacie so fth e LowerMiocen e 33 10 Thicknessan dsprea do fth eOligocenen/Uppe r Eocenedeposit s 34 11 Thethicknes so fth eUppe rCretaceou sdeposit s 35 12 Faciesma po fth eTuronian-Santonia n 36 13 Thethicknes so fth eCenomania ndeposit s 36 14 Occurrence andthicknes so fth eBahariy aShale s 38 15 Thethicknes so fth elowe rCretaceou sdeposit s 39 16 Occurrence andthicknes so fth eJurassi cdeposit s 39 17 Thedept hi nmetres-MS Lo fth ePrecambria nbas e deposits 40 18 Averagehydrauli c conductivityo fth eNubia n Sandstoneaquife r 46 19 Theaverag ek-valu eo fth edeposit so fth e MoghraFormatio n 46 20 Thechang eo ftemperatur e in28 9oi lwell s 49 21 Thetemperatur eo fgroundwate r inwel lnr .Q 6 49 22 Thethicknes so fth edeposit so fth eNubia n AquiferSyste m 51 23 Estimated transmissivityo fth elayer so fth e NubianSandston eComple x 51 24 Thethicknes so fth edeposit so fth eMoghr a Formation (JVQ-reports) 53 25 Thethicknes so fth edeposit so fth eMoghr a Formationaccordin gt oHanta r 53 26 Thetransmissivit y ofth edeposit so fth eMoghr a Formationbase do nFigs .1 9an d2 4 54 27 Thelocatio no fobservatio nwell s 55 28 Detailedma po fth eare aaroun dSiw aan dth e westernpar to fth eQattar aDepressio nwit hth e locationso fth eobservatio npoint s 56 29 Piperdiagra m ofth edat afro mth eow nfiel d campaign 57 30 Piperdiagra mwit hth edat afro mSwanber ge tal . 57 Page 31 Piperdiagra mo fth ewate ranalysi sdat afro m JVQ 58 32 The relationbetwee n thecalciu m andmagnesiu m concentrations ofdat a fromSwanber g 59 33 The relationbetwee n thecalciu m andmagnesiu m concentrations ofdat afro mJV Q 59 34 Therelatio nbetwee nth ecalciu m andmagnesiu m concentrations ofdat afro m theow nfiel ddat a 60 35 North-southprofil e throughth enorther npar to f theWester nDeser t 61 36 Therelatio nbetwee nth e,8 0an dD concentration s ofth esample so fth eow nfiel dcampaig n 63 TABLES 1 Stratigraphicalan dlithologica lsectio no fth e northernpar to fth eWester nDeser t 24 2 Dataabou tth econsistanc e offormation s inth e undergroundo fth eWester nDeser t 27 3 Summarizedgeologi c tableo fth enorther npar t ofth eWester nDeser t 45 4 Hydraulicconductivitie so fclasti csediment s withdifferen t lithologicalcomposition s 47 5 180an ddeuteriu m analysiso fth ewate rsample so f thefiel dcampaig n 63 PREFACE Inthi spape ra summar yi sgive no fth egeologica lan d geohydrologicalaspect so fth enorther npar to fth eWester n Desert inEgypt ,mainl ycompile dwit hhel po fdat afro m literature.I twil lb ea bas e forfurthe rexamination san dfo r fieldobservation s inEgypt .Th etopic stha tar eviewe d-mos t incollaboratio nwit hothe rinvestigators -i nthi spaper ,wil l be: -Geologica lan dgeohydrologica lapect so fth earea ; -Translatio no fth eobservation s toth ehydrologica lsituation ; -Hydrochemica laspects . Beside thatth eobjectiv eo fthi spape ri st ob ea startin g pointfo rdiscussion swit h those,wh oar eintereste dan d involvedi nth ewatermanagemen t situationo fsem iari darea s ingenera lan despeciall y inEgypt . Thanks tothos ewh ower e interestedi nth eforme rdraft san d theirvaluabl e remarks.Thi sdeal sespeciall yProf .Dr .Ismai l M.E lRamley ,Hydrogeologis to fth eDeser tInstitut ei nCairo , whointensel y reviewedth efirs tdraf to fthi spaper .Th e discussionswit hhi man dhi seffort st ointroduc em et oth e DesertInstute s library,ha dgrea tvalue sfo rm ywor ki nEgypt . Thanksals ot oDr .M .Menent ian dIng .W.G.M .Bastiaansse nfo r theirvaluabl eadvise san dco-operatio n inwor ki nEgyp tan d toou rEgyptia ncollègues ,especiall y Ing.M.H .Ab dE lKari m forcollaboratio nan dhospitalit y atth eResearc hInstitut e forGroundwate r (RIGW)i nCairo . 11 SUMMARY Duet oth edramati cgro wo fth epopulatio n inEgyp t therei sa greatnee dfo rextensio no fth eagricultura lare ai nth ecountry . Beside thatlos so fagricultura llan ddu et odesertificatio n mustb eprevented . Oneo fth emai nproblem si ssalisatio no fth esoil .Importan t ist oknow ,wha ti sth eorigi no fgroundwate r inth esubsoil , aswel li ntim ea si nspace .Therefor e theexistin gevaporatio n researcho fth eWinan dStarin gCentr ewit hhel po fsatellit e observations,ha dt ob esupplemente dwit hhydrogeologica l investigations. Manydat awer eavailabl e fromexploration s fordifferen t purposes.Importan twa sth einformatio n from theoi lcompanie s andth eresearc hfo rth es ocalle d "Hydro-solarprojec t Qattara". Inth econcernin gare ather ear elimite ddifference si n groundlevelelevations .Mainl y therei sa gradua lincreas eo f thegroundlevel s form theMediterranea ncoasta lare ai nth e southerndirection .I nth elandscap e therear edepression si n thelandsurface .Ther ei sa sequenc eo fsuc hdepression sfro m thesouth-eas t toth enorthwest ,accumulatin gi nth eQattar a Depression (2000 0 km2),wit hgroundlevel sbelo wsealeve l (deepestpoin t13 3m-msl )an dth eSiw aDepressio nnea rth e Egyptian-Libianborder . Inth edepression s isseepag eo fgroundwater .I nth e depressionswit hfres hwate rseepag ear eoases ,existin gsinc e theancient .Newl ydrille dwell sbesid e theold ,mos tnatura l wells,gav epossibilitie s forexpensio no fagricultura lare a andne wproduct sbesid e thetraditiona ldeser tproducts . Surpluso firrigatio nwate r flowst oth elowe rpart so fth e depressions,wher elake scam eint oexistanc ewit hhig hsal t contentsan dformatio no fsal tcrus tarea s ("sebkah1s"). The interfacebetwee nfres han dsal twate r isfoun dsom e30 0 kmsout ho fth eMediterrania ncoast .Nort ho fi textrem ehig h saltconcentration s arefoun di ngroun dan dsurfac ewater .I n thedepression sextende d "sebkah"area scam eint oexistanc ei n thearea swit hsal twate r seepage.Fres hde wwate raccumulatio n inth eunsaturate dpar to fth esubsoil ,make spossibl ethat , locally,natura lvegetatio nha sbee ncom e intoexistanc ei n baredeser tareas .