青藏高原拉萨河流域径流组成及驱动因素OA

Cryospheric change on the Tibetan Plateau is reshaping its hydrological processes and threatening regional water security.The Lhasa River,which is the largest tributary of the Yarlung Tsangpo River,is a typical example of a river in a meltwater-fed basin that is highly sensitive to climate change.Using the VIC-glacier model constrained by multisource datasets,including meteorological and hydrological observations,glacier inventories,and satellite snow products,the runoff components of the Lhasa River Basin during 1975-2016 were reconstructed and partitioned.The daily discharge was consistently reproduced at four gauges(Nash-Sutcliffe efficiency:>0.70;relative error:<10%).At the downstream gauge on the Lhasa River,mean annual runoff was dominated by rainfall runoff(75.8%),with snowmelt and glacier melt water contributing 22.2%and 2.0%,respectively;at the upstream Yangbajing gauge,glacier melt water accounted for 41.8%of runoff.Over the study period,snowmelt runoff declined substantially(-0.693 mm/a),whereas glacier meltwater runoff increased(0.047 mm/a).Precipitation was the primary control on runoff variability,while air temperature reshaped runoff composition by regulating meltwater processes,exhibiting pronounced seasonal contrasts.These findings provide a scientific basis for assessing water-resource changes and supporting adaptive management in high-altitude basins.