Response of Zhadang Glacier runoffin Nam Co Basin,Tibet,to changes in air temperature and precipitation form  

作　　者：ZHOU ShiQiao KANG ShiChang GAO TanGuang ZHANG GuoShuai 

机构地区：[1]Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China [2]State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China

出　　处：《Chinese Science Bulletin》2010年第20期2103-2110,共8页

基　　金：supported by the National Natural Science Foundation of China(40971050,40830743 and 40671045);the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-145,317);the National Basic Research Program of China(2005CB422004)

摘　　要：This paper describes 2007/2008 inter-annual changes in runoff from the Zhadang Glacier located on the northern slope of Nyainqêntanglha Range,Tibet,and analyzes their causes.Precipitation increased by 17.9%in summer months of 2008 compared with the same period in 2007,drainage basin runoff decreased by 33.3%,and glacial meltwater decreased by 53.8%.Change in positive accumulated air temperature explained approximately half of the inter-annual difference in glacial meltwater using a degree-day model.This suggests that the glacier is extremely sensitive to changes in air temperature.Energy balance analysis showed that change in glacier surface albedo,considered to be caused by difference in precipitation form,resulted in the large inter-annual difference in glacial meltwater.It was shown statistically that precipitation form in the summer months of 2007 was mainly rainfall which comprised 71.5%of total precipitation,while during the same period in 2008 rainfall accounted for 30.7%,with the majority of precipitation falling as snow.Precipitation form should be considered an independent factor when analyzing glacier sensitivity to climate change or forecasting the runoff from certain glaciers.This paper describes 2007/2008 inter-annual changes in runoff from the Zhadang Glacier located on the northern slope of Nyain- @ntanglha Range, Tibet, and analyzes their causes. Precipitation increased by 17.9% in summer months of 2008 compared with the same period in 2007, drainage basin runoff decreased by 33.3%, and glacial meltwater decreased by 53.8%. Change in posi- tive accumulated air temperature explained approximately half of the inter-annual difference in glacial meltwater using a de- gree-day model. This suggests that the glacier is extremely sensitive to changes in air temperature. Energy balance analysis showed that change in glacier surface albedo, considered to be caused by difference in precipitation form, resulted in the large inter-annual difference in glacial meltwater. It was shown statistically that precipitation form in the summer months of 2007 was mainly rainfall which comprised 71.5% of total precipitation, while during the same period in 2008 rainfall accounted for 30.7%, with the majority of precipitation falling as snow. Precipitation form should be considered an independent factor when analyzing glacier sensitivity to climate change or forecasting the runoff from certain glaciers.

关 键 词：降水形态 冰川变化 年径流量 气温变化 西藏 纳木错 盆地 冰川融水 

分 类 号：P343.6[天文地球—水文科学] O661.1[天文地球—地球物理学]