简介：Forrecentyears,runoffgenerationandhydrologicalprocessesinHailiutuRiverbasinhavebeengreatlychangedbyclimatechangeandhumanactivity,especiallywaterandsoilconservationconstruction.Inthisstudy,thetrendsinprecipitation,evapotranspiration(ET)andriverrunoffaswellastheeffectsofprecipitationchangeandhumanactivityonrunoffvariationhavebeenstudied.Theresultsshowedthatduring1960-2000,annualprecipitationandriverrunoff,monthlyprecipitationandETinSeptemberandOctoberaswellasmonthlyrunoffinallmonthsshowedasignificantdecrease.Inaddition,peakflowandbaseflowhadalargedecrease.Underthejointinfluenceofprecipitationchangeandhumanactivity,themeanannualrunoffdecreasedby35millionm3fromthebaselineperiod(1960-1985)tothechangeperiod(1986-2000),whichaccountedfor60.9%and39.1%ofthetotalrunoffdecrease,respectively.Precipitationchangeplayedaprimaryroleinthedecreaseofannualrunoffwhereashumanactivity,particularlywaterandsoilconservationconstruction,alsohadremarkableimpactsonrunoffvariation.

简介：Thefractionsofriverrunoffandsea-icemeltedwaterintheCanadaBasininsummer2003weredeterminedbythesalinity-18Osystem.Thefractionofriverrunoff(fR)washighintheupper50mofthewatercolumnanddecreasedwithdepthandlatitude.Thesignalsoftheriverrunoffwereconfinedtowaterdepthsabove200m.ThetotalamountofriverrunoffintheCanadaBasinwashigherthanthatinotherarcticseas,indicatingthattheCanadaBasinisamainstorageregionforriverrunoff.Thepenetrationdepthofthesea-icemeltedwaterwaslessthan50mtothesouthof78°N,whileitwasabout150mtothenorthof78°N.Thetotalamountofsea-icemeltedwaterwasmuchhighertothenorthof78°Nthantothesouthof78°N,indicatingthesea-icemeltedwatersaccumulatedontheiceedge.Theabundantsea-icemeltedwaterontheiceedgewasattributedtotheearliermeltedwaterinthesouthernCanadaBasinandtransportedbytheBeaufortGyreorthereinforcedmeltingofseaicebysolarradiationinthepolynya.