摘要
Climatechangecharacterizedbyincreasingtemperatureisabletoaffectprecipitationregimeandthussurfacehydrology.However,themannerinwhichriversedimentloadsrespondtoclimatechangeisnotwellunderstood,andrelatedassessmentregardingtheeffectofclimatechangeonsedimentloadsislacking.Wepresentaquantitativeestimateofchangesinsedimentloads(from1.5Gtyr~(-1)pre-1990to0.6Gtyr~(-1)from1991-2007)inresponsetoclimatechangeineightlargeChineserivers.Overthepastdecades,precipitationchangecoupledwithrisingtemperatureshasplayedasignificantroleininfluencingthesedimentdeliverydynamics,althoughhumanactivities,suchasreservoirconstruction,waterdiversion,sandminingandlandcoverchange,arestillthepredominantforces.Lowerprecipitationcoupledwithrisingtemperatureshassignificantlyreducedsedimentloadsdeliveredintotheseainsemi-aridclimates(4-61%).Incontrast,increasinglywarmerandwetterclimatesinsubtropicalzoneshasyieldedmoresediment(0.4-11%),althoughtheincreasewasoffsetbyhumanimpact.Ourresultsindicatethat,comparedwithmechanicalretentionbyreservoirs,waterreductioncausedbyclimatechangeorhumanwithdrawalshascontributedmoresedimentreductionfortheriverswithabundantsedimentsupplybutlimitedtransportcapacity(e.g.,theHuanghe).Furthermore,ourresultsindicatethatevery1%changeinprecipitationhasresultedina1.3%changeinwaterdischargeanda2%changeinsedimentloads.Inaddition,every1%changeinwaterdischargecausedbyprecipitationhasledtoa1.6%changeinsedimentloads,butthesamepercentageofwaterdischargechangecausedlargelybyhumanswouldonlyresultina0.9%changeinsedimentloads.Thesefigurescanbeusedasaguidelineforevaluatingtheresponsesofsedimentloadstoclimatechangeinsimilarclimatezonesbecausefutureglobalwarmingwillcausedramaticchangesinwaterandsedimentinriverbasinsworldwideatratespreviouslyunseen.
出版日期
2013年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
