简介：ViathevaluableopportunityoftheThreeGorgesReservoir(TGR)135-mfillinginJune2003,theYangtzedischargeandsuspendedsedimentconcentration(SSC)enteringtheestuaryduringtheperiodfrom15Mayto15July2003wereanalyzedtoexaminetheinstanteffectsofthefillingonthem.TheYangtzedischargeandSSCenteringtheestuaryintheperiodsbefore,duringandafterthefillingclearlyindicatedthreephases:1)thepre-storagephasecharacterizedbynaturalconditions,inwhichtheSSCincreasedwithincreasingwaterdischarge;2)thestoragephase,duringwhichtheSSCdecreaseddramaticallywithdecreasingwaterdischarge;and3)thepost-storagephase,duringwhichboththeSSCandwaterdischargeremainedatrelativelylowlevelsfirstuntiltheendofJune,thentheSSCincreasedgraduallywithincreasingwaterdischarge.ItseemsthatthetimesfortheinstanteffectsofthedecreasingdischargedownstreamfromtheupperYangtzeontheYangtzedischargeandSSCenteringtheestuaryduetotheTGR135-mfillingtotakeplacewereabout5dand1drespectively,whilebothwereabout18dforthoseoftheincreasingdischarge.Thisprobablyreflectsthebufferingandresultantlyhysteresisofthe1800-kmstretchfromtheupperYangtzetotheestuary.TheresultsarehelpfulforscientificandhydrologicalinvestigationoftheYangtzemainstreamdownstreamfromtheTGRDamandoftheestuarineandadjacentcoastalwaters.