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1LiteraturesSource第1页/共44页Articlestructure1、Titleandauthor2、SummaryPhase4Phase3Phase2Phase11、Introduction2、Background1、Sampling2、Analyses

1、ResultsandDiscussion2、Conclusions3、references第2页/共44页12334435

Summary

ContentsIntroductionandBackgroundSamplingandAnalysesResultsandDiscussion

Conclusions第3页/共44页41.Summary1、提出问题:TheLowerTarimRiverinNWChinaisundersevereecosystemdegradationduetostoppedstreamflowanddiminishedgroundwaterrecharge.Sinceyear2000,eightwaterdiversionsfromtheupperstreamandfromtheneighboringKaidu–KongqueRiverhavebeenimplementedtoalleviatetheecosystemdisaster.中国西北部塔里木河下游面临严重生态退化是由于河流断流和地下水补给减少造成的。自2000年以来,通过从邻近的开都和孔雀河等河流上游的八次引水调度已经缓解塔里木河生态环境问题。第4页/共44页51.Summary2、研究方法:wesampledtheripariangroundwatersystemin2007and2008alongthe350km-longriverchannelthroughthe40monitoringwellssituatedalongninetransectsperpendiculartotheriverandthreesoilprofiles.Measurementsonthesampleshaveincludedenvironmentalisotopes(18O,²H,³H)andwaterchemistry.我们沿河岸地下水系统在2007年和2008年沿着350公里河道,通过40个坐落在河流附近的监测井进行采样。测量样品项目包括环境同位素(18O,²H,³H)和水化学。第5页/共44页61.Summary3、研究结果:Remarkablechangeshavebeeninducedbythewaterdiversions

asfollows：(1)Theobservedresponseofripariangroundwatersystemincludesgeneraldecreaseintotaldissolvedsolid(TDS)andriseofwatertable.Greaterriseofwatertableoccursneartheriverbank.沿河岸地下水系统观察结果包括:总溶解固体(TDS)减少和水位上升。更大的地下水位上升发生在河岸附近。(2)Tritiumdatashowthattheextentofmodernrecharge(since1960s),includingthatfromthedivertedwater,islimitedto600mfromtheriverbankattheuppersegmentsand200matthelowerones.氚数据显示,现代水补给范围(since1960s),包括从转移水,仅限于上游河岸600米内部分和下游200米内。第6页/共44页71.Summary(3)Stableisotopesshowthatgroundwatersareenrichedinheavyisotopesandareplottedinparalleltothemeteoricwaterline,attributedtoevaporationduringrecharge.稳定同位素表明,地区地下水重同位素丰富,并与大气降水线平行,归因于蒸发。(4)GroundwaterisgenerallyofNa–Mg–Cl–SO4typeandisformedbydissolutionofminerals.Thesalinityofgroundwaterismainlyaffectedbythatofthedivertedwaterandofthelocalantecedentgroundwater,saltsintheunsaturatedzone,evapotranspirationduringrecharge.地下水一般由Na-Mg-Cl-SO4类型和溶解的矿物质组成。地下水盐度主要是受转移水和当地前期地下水,在非饱和区的盐度,蒸散发影响。第7页/共44页81.Summary(5)Asthezoneofsmallergroundwaterdepth(lessthan5m)suitableforthemostexistingPopuluseuphraticaandTamarixramosissima,themainspeciestargetedbytherescueeffort.正如较小的一部分区域地下水深度(小于5米)适用于大多数现有胡杨和柽柳,它们是保护的主要目标。第8页/共44页92、IntroductionandBackgroundWaterdiversionGeneralsettingHydrogeologyClimateEcosystemdegradationIntroductionandBackground第9页/共44页102、IntroductionandBackgroundIntroduction:Underthedualimpactsofanthropogenicactivitiesandclimatechange,acommonscenarioinaridandsemiaridcatchments,particularlyinthelowerreachesofthem,issevereecologicaldegradation,suchasdeathofvegetation,intensifiedgroundwatersalinization,soilsalinizationanddesertification,etc.介绍：人为活动和气候变化的双重影响下,一个常见的场景在干旱和半干旱区,特别是在下游,是严重的生态退化,如植被死亡,加剧地下水盐渍化、土壤盐渍化、沙漠化等。

第10页/共44页11Background:1、GeneralsettingTheTarimRiverBasinislocatedinthesouthofXinjiang,NWChina.Ithasanareaof1.04x106km2andisflankedbytheTianshanMountainstothenorthandbytheKunlunMountainstothesouth(Fig.1).2、HydrogeologyTheoccurrenceofgroundwaterissimilarbetweentheSouthernTianshanwatershedandNorthernKunlunwatershed.ThesinkofthetwogroundwaterssystemsiscenteredinthesouthoftheTarimRiver.Thediluvialaquiferfromthenorthernmountainsiscomposedofsanddepositssome100–300mthickforminganunconfinedaquiferinwhichthepresentdaywatertablerangesbetween20mand200mbelowsurface(Fig.2).

2、IntroductionandBackground第11页/共44页12Fig.1SketchmapoftheTarimRiverBasin1–Proterozoic;2–Paleozoic;3–Mesozoic;4–tertiary;5–granite;6–quaternary;7–river;8–surfacewaterintheUpperTarimRiverandtheAksuRiver;9–regionalgroundwaterflow.第12页/共44页13Fig.2HydrogeologicalcrosssectionintheMiddleTarimRiver,seeFig.1forthelocation第13页/共44页14Background:3、ClimateTheLowerTarimRiverisdominatedbytypicalcontinentaltemperatearidclimate.4、EcosystemdegradationUndertheimpactofanthropogenicactivities,runoffofthreesourcestreams(AksuRiver,HotanRiverandYarkantRiver)totheTarimRiverhasdecreasedgraduallyinthelast50yearsduetoextensiveoasisagriculturewithincreasingwaterutilization.WithgraduallydecreasedinflowtotheTarimRiver,proportionofwaterconsumptionintheupperandmiddlereachesincreasedgraduallyfrom1970sto1990s,whileflowtothelowerreachesreducedsignificantly(Table1).Thegroundwaterdepthhasincreasedto8–12m.

2、IntroductionandBackground第14页/共44页Station1950s1960s1970s1980s1990sAral49.451.744.444.842.0Qiala13.511.46.73.92.8Tikanlik8–92.90.50.40.1ArganPersistDiscontinueNilNilNilLopVillage5–40.2NilNilNil15Table1RunoffchangesateachstationontheTarimRiver(108m3).5、WaterdiversionToprotecttheGreenCorridor,theriparianvegetationrestorationisimperative.TakingadvantageofthewetperiodoftheKaiduRiver,theKu–TaChannel(YulitoQiala,Fig.3)wasconstructedfordivertingwaterfromKongqueRivertotheLowerTarimRiver.

第15页/共44页16Fig.3Samplinglocations

第16页/共44页17

Table2Statisticsofeightwaterdiversions第17页/共44页183.SamplingandAnalyses采样点布置及前期准备稳定同位素测定方法及标准18O,²H,³H稳定同位素测量八次引水后塔里木河流域下游地下水的物理化学变化规律及特征水化学测定方法及标准采样方法及具体实施步骤水化学离子色谱法测定地下水位、位置,水温、pH值、TDS和电导率测定第18页/共44页19Sampling：Groundwatersampleswerecollectedfromboreholesatvaryingdistancesfromtheriverbedalongninegroundwatermonitoringtransects,namely:Akdun(A),Yahopumarhan(B),Yengsu(C),Abudali(D),Karday(E),Tugmailai(F),Aragan(G),Yikanbujima(H),andKargan(I)(Fig.3),respectively.Method：Thesoilsampleswereobtainedusingahollow-stemhandaugerwithinterchangeable1.5maluminumrodfromthreeprofiles(5.8–7.7mdepth,SP1andSP2insectionCandSP4insectionG,Figs.3and4).Bulksoilsamplesof400gwerecollectedatintervalsof0.25m.Sampleswerehomogenizedoverthesampledintervalandimmediatelysealedinpolyethylenebags.3.SamplingandAnalyses第19页/共44页20Method：Gravimetricmoisturecontentwasdeterminedbydryingaminimumof80gofsoilat110Cfor12h.Todeterminechloridecontent,doubledeionisedwater(40mL)wasaddedtotheoven-driedsoilsample(40g).Sampleswereagitatedonareciprocalshakertablefor8h.Thesupernatantwasfilteredthrough0.45lmfilters.Chloridewasthenanalyzedbyionchromatography.Thechlorideconcentrationofthesoilsolutionisthencalculatedbydividingthemeasuredconcentrationbygravimetricmoisturecontentandbymultiplyingthemassratioofsolutiontoovendrysoil.3.SamplingandAnalyses第20页/共44页21

Table3Sitemeasurementsandisotopiccompositionofsurfacewaters.Analyses：第21页/共44页22

Table4Chemicalcompositionofthesurfacewaterandgroundwatersections(mg/L).第22页/共44页23

4.ResultsanddiscussionPhase1Phase2Phase3TritiumandstableisotopeanalysisHydrochemicalcharacteristicsWatertableandTDSchange第23页/共44页24

Fig.4Theprecipitationtritiuminputfrom1952to2007andthedecayedvaluefor2007.Theresultsshowatritiumcontentdecreasefrom2586TU(1963)to20~30TU(2007).Usinganexponentialdecayequation,thedecayedtritiumcontentsfor2007inprecipitation,whichwouldrepresenttritiumconcentrationsingroundwaterthathadinfiltratedbetween1952and2007,rangesfrom50TUto225TUfrom1962to1966,andrangesfrom10to35TUfrom1957to2007(Fig.4).Therefore,groundwaterwithtritiumcontentlessthan10TUisregardedaspre-modernwater,oratleastmostpartispre-modernwaterwhenmixingwithmodernwaterisconsidered.Tritiumanalysis第24页/共44页25Fig.5.PostmapofTritiumcontent(TU)forgroundwatersfromtheLowerTarimRiverwithasolidlineshowingthescopeofmodernrecharge.Fig.5showsthetritiumcontentsintheripariangroundwaterfromtheLowerTarimRiver.Thesolidlineinthefigureistheboundarybetweengroundwaterthatisrechargedbymodernwater(19.1–46.3TU)andthatbypre-modernwater(lessthan4.1TU).Tritiumanalysis第25页/共44页26Fig.6Thestableisotopesinthewaterreservoirsinthelowerreachesareenrichedinheavyisotopesduetoevaporation:theQialaWaterReservoirhastheδ18Oof4.6‰andtheDaxihaiziWaterReservoirhastheδ18Oof3.6‰duetoextendedevaporation.TheresidualwaterscollectedfromtheriverbedattheLowerTarimRivershowδ18Ofrom2.0‰to3.5‰andδ2Hfrom17.1‰to5.8‰,asaconsequenceofintensiveevaporation.StableisotopeanalysisinsurfacewatersFig.6Stableisotopiccompositionforsurfacewatersandgroundwaters第26页/共44页27Themodernandpre-moderngroundwatersexhibitasimilarbehaviortofallinslightparalleltothemeteoricwaterline,butenrichedrelativetotherechargingriverwater.Thephenomenoniscommonlyobservedindryclimateandattributedtoevaporationduringriverrechargetotheripariangroundwatersysteminaratheruniformmanner.Fig.7StableisotopiccompositionforsurfacewatersandgroundwatersStableisotopeanalysisingroundwatersFig.6Stableisotopiccompositionforsurfacewatersandgroundwaters第27页/共44页28piper三线图以三组生要的阳离子(Ca,Mg,Na和K)和阴离子(C1,S04,HCO3和CO3)的每升毫克当量的百分数来表示。每图包括三个部分，在左下方和右下方分别为二张等腰三角形域，中间上方夹着一张菱形域(图1)，每域的边长均按100等分读数。在左下方的等腰三角形域，三个主要阳离子反应值的百分数按三线座标用一个单点表示。在右下方的等腰三角形域，阴离子亦用同样方法表示。这样，图上所作的二单点表示了地下水中某些溶解物质的相对浓度。然后通过这二个单点平行三角形外边作射线，于菱形域内相交一点。这一点通常可以说明地下水总的化学性质并用阴阳离子对表示地下水的相对成分。Hydrochemicalcharacteristics第28页/共44页29ThewatertypeconversionfromCa–Mg–HCO3–SO4withlowTDSinsourcestreamtoNa–Mg–Cl–SO4withhighTDSinthelowerreachesofthebasinandfluorideconcentrationevolutionshowtheoneofthemosttypicalwaterevolutionofaridwatersystem,goingalongwithevaporationanddissolution.Fig.7Pipertrigraphforsurfacewaters（a）andgroundwaters（b）Hydrochemicalcharacteristics（a）（b）第29页/共44页30TDSinthegroundwaterwithin600mtotheriverbedrangesfrom0.8g/L(E3)to3.7g/L.(C1)withanaverageof1.6g/L,exceptforsectionI,whichislocatedintheterminalofthewaterflowandsaltwithveryhighTDS.Beyondthedistance,TDSingroundwaterisalsohighexceptforsampleG5.Fig.8TDSdistribution(g/L)intheLowerTarimRiverHydrochemicalcharacteristics第30页/共44页31ThestrongcorrelationsbetweenNaandCl(r=1.00)andanapproximately1:1trend(Fig.9a)suggestNaandClmainlycomesfromhalite.CaandMghavestrongcorrelationswithSO4(0.97,1.00)andrelativelyweakwithHCO3(0.77,0.84).Theequivalentratiosfor(Ca+Mg)againstHCO3aremorethan1(Fig.9b),suggestingthat,besidesdissolutionofcarbonates,dissolutionofsulfate(CaXMg(1-X)SO4)contributestheadditional(Ca+Mg)whenconcentrationof(Ca+Mg)increaseswiththatofSO4.Suchapatternindicatesthatsaturationofarelevantsaltcontrolstheconcentrationoftherespectiveions.Fig.9Ionicratioforthegroundwaters.Groundwatersaliizationmechanism第31页/共44页32Fig.10showsthechlorideconcentrationindrysoil,appearingtobehighlyvariable.TheSP1haslesschlorideinthewholeprofile,rangingfrom24to862mg/kg,comparedtotheSP2andSP4,whichshowmaximumchlorideconcentrationof4416mg/kg(2.05–2.30mdepth)and11,925mg/kg(0.35–1.00mdepth),respectively.Fig.10Moistureandchloridecontentforthethreesoilprofiles第32页/共44页33Fig.11WatertablesandTDSchangesatcertaingroundwatermonitoringsectionintheLowerTarimRiverunderwaterdiversions第33页/共44页34Thevariationsofwatertableshavethefollowingcharacteristics:beforethewaterdiversion,thewatertablesweresimilarateachsectionandtheflowfieldwasstable;afterthewaterdiversion,thewatertablesrosetodifferentextent.Theclosertotheriverbed,thefasterthegroundwatertablerose.Theunstableinfiltrationtakesplaceatriverbed,asaresult,thehighgroundwaterhydraulicheadmovestowardsbothriver-sides.ChangesofTDSingroundwatersshowthefollowingcharacteristics:TDSingroundwaterfromsectionsBandChasincreasedafterthefirstdiversion;afterthesecondandthirdwaterdiversions,TDSingroundwatersfromallsectionshasdecreased.TheTDSforsamplesC7(w8,850mawayfromtheriver)tempestuouslyincreasedfrom4.57g/Lto22.37g/Lafterthefourthwaterdiversion,to15.32g/LinAugust,2007.WatertableandTDSchange第34页/共44页35Fig.12Thevariationofgroundwatertable(m)beforewaterdiversionandaftertheeighthwaterdiversion(a)andgroundwaterdepth(m)intheLowerTarimRiver(August,2007).Thevariationofgroundwatertablebetweenthatbeforewaterdiversion(05/2000)andaftertheeighththewaterdiversion(08/2007)andthegroundwaterdepth(08/2007)areplottedinFig.15usingtheInverseDistanceWeightingMethod.4.Resultsanddiscussion第35页/共44页36Thescopesofwatertablesrisearewiderthanmodernrechargelimit,duetowaterheadpressuretransfer.Sincethevegetationcoverageexhibitsacontinueddecliningtrendwithdroppingwatertableandmodernwaterrechargescopeinthearea,NiuandLi(2008)concludedtherewas7345hm2increasedvegetationareafrom2000to2006afterwaterdiversionbasedonsatelliteimagesofthemainareawherevegetationdistributedintheLowerTarimRiver.

However,thegroundwaterdepthsuitableforthegrowthofP.euphraticaislessthan5mintheLowerTarimRiver,IfthetargetoftheecologicalrestorationistomaintainthevegetationdominatedbyP.euphratica,theoptimalgroundwaterdepthwouldbelessthan5m.However,theterritorywiththesuitablegroundwaterdepthisnarrow,within200mfromtheriverbedandbecomesevennarrowertowardsdownstream4.Resultsanddiscussion第36页/共44页371、TheisotopiccompositionofshallowgroundwaterformsatrendlinethatisalmostinparalleltotheGMWLbutisenrichedinheavyisotopescomparedwiththerechargingriverwater.Thiscanbeattributedtoevaporationduringtheriverrechargetotheripariangroundwatersysteminaratheruniformmanner.浅层地下水的同位素组成,形成一个趋势线,几乎是平行于GMWL，与河水相比重同位素值更大。归因于河水补给地下水系统过程间的蒸发作用。2、Tritiumdatashowthattheextentofmodernrecharge(since1960)islimitedto600–200mfromtheriverbankwithadescendingtrendtowardsdownstr