低水位运行对天目湖水库水质与生态的影响

201127487－94JournalofEcologyandRuralEnvironment1①211331.2100082.2100983.213333200882004—20081.73m、。20089—20098ρTN12009217—227ρTN0.922.09mg·L－1ρTP2009200820096—81730L－14188L－120081200821%2009Chl-a2008。、、。。X524A1673－4831201104－0087－08EffectsofLowWaterLevelonWaterQualityandEcologyofTianmuhuReservoirChina．ZHUGuang-wei1ZHAOLin-lin2CHENWei-min1XIEChun-gang1GAORong-ping3ZHOUShi-ping31．StateKeyLaboratoryofLakeandEnvironmentNanjingInstituteofGeographyandLimnologyChineseAcademyofSciencesNanjing210008China2．CollegeofHydrologyandWaterResourcesHohaiUniversityNanjing210098China3．ShaheReservoirManagementOfficeofLiyangLiyang213333ChinaAbstractEffectsoflowwaterlevelonwaterqualityandecologyoftheTianmuhuReservoirLiyangChinawereevalua-tedbymeansofhigh-frequencyinsitumonitoringofthewaterqualityandplanktoninthereservoirduringtheperiodfromSeptember2008tillAugust2009whenthewaterlevelofthereservoirwaslowereddownby1.73mbelowthemeanwaterleveloftheyears2004－2008forreinforcement．Itwasfoundthatthereservoirweakeneditsbufferingcapacityofincomingexogenousnutrientsinthatyearoflowwaterleveloperation．PeaksofTNconcentrationwascloselyrelatedtoheavyrain-fall．OneearlyspringheavyshowerFeb．17－272009immediatelyledtoasharpriseoftheρTNofwaterbodyfrom0．92to2．09mg·L－1whichreturnedtonormalonlyaftertheendofthesummerstormseason．TPconcentrationinthewaterbodywasmainlyaffectedbythebiomassofplanktonandthecontentofsuspendedsubstancesthereinandlittlebythelowwaterlevel．Inthesummerof2009theproportionofCyanophytaamongthephytoplanktonwasobviouslyhigherthanthatinthesummerof2008suggestingthattheentirealgacommunitystructuretendedtowardsthatundereutrophication．ComparedwiththatinJuneAugust2008themeanabundanceofprotozoawas1730L－1andofrotaria4188L－1inJuneAugust2009almostdoubledthatofcopepoddecreasedby21%butofcladocerafluctuatedsharply．MoreovertheChl-anutritionindexofthewaterbodyincreased．Ingenerallowwaterlevelmakesthewholeecologicalsystemmorefragileandthefundamentalelementsoftheecosystemsuchaszooplanktonphytoplanktonandnutrientsfluctuatemoresharplyandthewaterbodymoresusceptibletochangesinenvironmentalconditions．Itisthereforesuggestedthatitisessentialtokeepasuitablewaterlevelinmanagementofreservoirsintermsofwaterqualityandecology．Keywordslowwaterlevelreservoiraquaticecologyeutrophication2011－01－032008CB4181032009ZX07101－01340730529①[e-mail]·88·272008863536924m352931831。2、、2。2。、、、、3－6、。2050200824241。1。、。119°25'N31°17'E150km212km27m12m7×108m3。。4A。21、7－8、910。11。、12。200882m。7m、、。11.1200899—200982。2004—20081。120081124a。2009811283d2004—20081.73m20096262.78m2009217。14aFig．1Waterlevelsduringthereinforcementperiodandthemeansofthepreceding4years20085—2009128～102。20085—111200812—20093120094—8120099—1112009121。4·89·2Fig．2SamplingsitesintheTianmuhuReservoir1.2SD、pH、EC、DO、TBYSI6600。1LOlympusCH。255LOlympusSZOlympusCH。TN、TP、DTN、DTP0.45μmGF/FTN、TPSkalarSys-temSkalarNH+4、NO－3、PO43－-P、NO－2aChl-aSSGF/F105℃550℃2hLOICODMn。22.120085—20091249TN、DTN、NO－3、NH+4、NO－23。320085—200912Fig．3VariationofconcentrationsofvariousfractionsofnitrogeninthewateroftheTianmuhuReservoirduringtheperiodfromMay2008tillDecember20093DTNTN79%。NO－3TN46%DTN57%。2009227—55TNGB3838—2002《》Ⅴ≤2.0mg··90·27L－1。42009227TN。42009126—216227TN121761～2d31mm24h9mm。、、24h0.1～9.9mm6。。21722614、7、8、0、15、21、8、26、9、34mm3d24h17.0～37.9mm。12009217—3216.89m18.55m22718.32m1.43mTN。420089—200912Fig．4DailyrainfallinTianmuhuduringtheperiodfromSeptember2008tillDecember200916.89、18.32m1.59×107、2.40×107m32009217—270.81×107m3。12km20.19×107m3215—27159mm0.62×107m3。2162———14TN3.41mg·L－10.62×107m3TN21.05t。215—26TN1.30～7.00mg·L－12.94mg·L－14TN4.20t。217—271.43mTN25.25t。21716.89mTN0.92mg·L－1227TN1.59×107m3×0.92mg·L－1+2.52×1010mg/2.40×107m3=1.66mg·L－180%。227TN2.09mg·L－1。TN21650cm。126。200923TNTN200811、2009811334TN。。20093TN20099TNGB3838—2002《》Ⅲ1.0mg·L－1。。2.2TP、DTPPO43－-P5。5TP0.009～0.063mg·L－10.033mg·L－1。TPGB3838—2002《》Ⅲ≤0.05mg·L－1TPⅣ≤0.1mg·L－12008918、11152009612、74、1020。15Ⅳ。5DTPTP40%PO43－-PTP13%。4·91·2。520085—200912Fig．5VariationofconcentrationsofvariousfractionsofphosphorusinthewateroftheTianmuhuReservoirduringtheperiodfromMay2008tillDecember20096TP、aSS。6200921SSSS200962SS。620085—200912TP、Chl-a、SSFig．6VariationofconcentrationsofTPChl-aandSSinthewateroftheTianmuhuReservoirduringtheperiodfromMay2008tillDecember20096TP。TP。TP。200929—313aTP1。TP·92·27TP。2.3。。20081.55×109L－118.14mg·L－120091.04×109L－110.40mg·L－1。。7。72009551813.6mg·L－152826.8mg·L－1。Bacillariophyta、Cryptophyta、Cyanophyta37%、29%18%。370%～94%84%。2009200820092008。2009。。720085—200912Fig．7VariationoftheproportionofdominantalgaofthephytoplanktoninbiomassinthewateroftheTianmuhuReservoirduringtheperiodfromMay2008tillDecember20092.4。20083794L－11.89mg·L－120093918L－11.69mg·L－1。、。20082009。6—820086—8740L－12183L－120096—81730L－14188L－11。。。4·93·。、、。2008529—83017.8L－1200914.1L－121%8。2008580.5L－120091.3L－11。20092008。82009。820085—200912、Fig．8VariationoftheabundanceofcladoceraandcopepodinthewateroftheTianmuhuReservoirduringtheperiodfromMay2008tillDecember20093。、trophicstateindexTSI。3aChl-a、SD、TPITSChl-a、ITSSD、ITSTP11I