J.Geogr.Sci.2023,33(3):576-598DOI:https://doi.org/10.1007/s11442-023-2097-7©2023SciencePressSpringer-VerlagImpactofcascadereservoirsonthedelayedresponsebehaviourofsedimentationintheThreeGorgesReservoirLIXin1,RENJinqiu2,3,XUQuanxi4,YUANJing4,*ZHANGWei11.StateKeyLaboratoryofWaterResourcesandHydropowerEngineeringScience,WuhanUniversity,Wuhan430072,China;2.ChangjiangSurvey,Planning,DesignandResearchCo.,Ltd.,Wuhan430010,China;3.HubeiKeyLaboratoryofBasinWaterSecurity,Wuhan430010,China;4.BureauofHydrology,ChangjiangWaterResourcesCommission,Wuhan430010,ChinaAbstract:Delayedresponsebehaviourcommonlyoccursinconjunctionwithchangesinriv-erbedscouringandsedimentdepositionandisakeycomponentinunderstandingtheintrin-sicbehaviourofreservoirsiltation.Duetothecomplexityoftheriverbedsiltationprocess,thevariabilityinthefactorsthatinfluencesiltationandthelimitationsofavailableresearchmethods,theunderstandingofthedelayedresponsebehaviourofthesedimentationprocessintheThreeGorgesReservoir(TGR)iscurrentlymerelyqualitative,andthereisalackofquantitativein-depthunderstanding.Inaddition,theeffectsofchangesinwaterandsedimentconditionsonsedimentationintheTGRbeforeandaftercascadereservoirimpoundmenthavenotbeenquantified,sofurtherstudiesareneededtoprovideareferenceforbetterun-derstandingtheintrinsicbehaviourofsedimentationintheTGRandtheimplicationsforthelong-termuseofthereservoir.Basedonmeasuredwaterandsedimentdatafrom2003to2020andtopographicdatafrom2003to2018,adelayedresponsemodelforsedimentationintheTGRisconstructedandcombinedwiththeoreticalderivationtoanalysethechangesinthedelayedresponsebehaviouroftheTGRbeforeandaftertheimpoundmentofthecascadereservoirsandtheassociatedcauses.Then,theinfluenceofchangesinwaterandsedimentconditionsinpreviousyearsonsedimentationinthereservoirareaisdetermined.Theresultsshowthat(1)theimproveddelayedresponsemodelofsedimentation,whichconsidersvari-ationsinexternalwaterandsedimentconditions,reservoirscheduling,andriverbedadjust-mentrates,caneffectivelyreflectthesedim...
