Page 60 - 2023年第54卷第11期
P. 60
Studyonthespatial - temporalvariationsofrunoffand
sedimentinthelowerreachofJinshaRiver
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XIEYiqin ,DENGAnjun ,DONGXianyong,QINLeilei,ZHANGBangwen 1,2
(1.StateKeyLaboratoryofSimulationandRegulationofWaterCycleinRiverBasin,ChinaInstituteof
WaterResourcesandHydropowerResearch,Beijing100048,China;
2.KeyLaboratoryofSedimentScienceandNorthernRiverTraining,theMinistryofWaterResources,
ChinaInstituteofWaterResourcesandHydropowerResearch,Beijing100048,China;
3.ChinaThreeGorgesConstructionManagementCo.,Ltd,Chengdu610041,China)
Abstract:Thevariationsoftherunoffandsedimenthaveagreatimpactondepositionprocessandtheoptimaloper
ationofthelargecascadereservoirsinthelowerreachoftheJinshaRiver (LJR).Alongwiththeconstructionofthe
largecascadereservoirs ,thepatterns(space - time)ofrunoffandsedimenthavechangedsignificantlyintheLJR.
Basedontheobservedhydrologicaldataofmainstream andtributariesintheLJR overtheyears,thevariation
processoftherunoffandsedimentwereanalyzedandthepatternsoftherunoffandsedimentindifferentperiods
wereproposed.Intermsoftimeline ,theannualvariationsoftherunoffcomingfrom theJinshaRiverstem,the
maintributariesofYalongRiver ,LongchuanRiverandNiulanRiver,aswellastheothersmalltributarieswere
notremarkable ;whilethesedimentloadvariationtrendsoftheabove - mentionedthreesourcepartsweredeclined
significantly ,obviouslyandnotsoobviously,respectively.Intermsofdistribution,theproportionsoftherunoff
intheJinshaRiverstem ,thelargesttributariesYalongRiverandothertributarieschangedlittleindifferentperiods
around46%,45% and9%;whiletheproportionsofthesedimentloadintheseregionschangedsignificantlyin
differentperiods.Before1999 ,theproportionofthesedimentloadintheJinshaRiver,theYalongRiverandother
smalltributarieswere40%,36% and24%;afterErtanReservoirconstructed,whichlocatedinYalongRiver,
from1999to2010,theproportionschangedto61%,13% and26%,respectively;while,afterthecascaderes
ervoirsinthemiddlereachesoftheJinshaRiverconstructedfrom2013—2020,theproportionswere16%,31%
and53%,respectively.Furthermore,separatingtheunobservedareaasindependentregionasconcerning,there
werenosignificantchangesfortheincomingrunoffoftheLJRneitherindifferentperiodsofthelargereservoirscon
structedinthemainstreamanditstributaries ,norinthedistributionsofJinshaRiver,YalongRiver,othertribu
tariesandunobservedarea ,theproportionsofwhichwerearound40%,40%,9% and11%,respectively.On
thecontrary ,theincomingsedimentloaddistributionchangesremarkablyindifferentperiod.Beforethereservoirs
constructedin2013,theproportionsofthesedimentloadintheJinshaRiver,theYalongRiver,othertributaries
andtheunobservedareaswerearound21%,19%,12% and48%.Whileowingtothereservoirsedimentretention
ofmiddleJinshaRiver,97% ofthesedimentloadcomesfromthebothsidesoftheLJRcatchment,including82%
fromunobservedareasand15% from themaintributaries.Itshouldbedrawtheconclusionthat,currently,the
sedimentfromtheunobservedareasisthemainsourceofsedimentatpresentinthelowerreachofJinshaRiver.
Keywords:lowerreachofJinshaRiver(LJR);runoffandsedimentpatterns;unobservedareas;reservoirssedi
mentretention
(责任编辑:李福田)
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