中文摘要：

采用HBV水文模型,对长江源区有冰川覆盖的冬克玛底河流域日径流进行了模拟试验研究.使用冬克玛底河流域周边4个有长期观测资料的气象站日气温、日降水数据,结合流域内自动气象站实测数据,应用多元回归法插值恢复了流域1955—2004年日气温数据,应用降水梯度与反距离权重相结合的方法恢复了流域1955—2004年日降水数据.采用数据质量较好的2004/2005年度和2006/2007年度两个物质平衡年水文气象数据进行模型参数的率定,应用2005/2006年度和2007/2008年度水文气象数据进行模型参数的检验.在确定模型能较好的模拟流域年月径流深的前提下,采用率定好的模型参数和恢复的气象资料,恢复了1955—2004年冬克玛底河流域的年径流深;依据水量平衡原理,得到流域冰川物质平衡变化.结果表明：1955—2008年冰川物质平衡呈亏损趋势,平均-136.0mm.a-1;年径流深呈波动增加趋势,平均增加5.61mm.a-1.径流深的增加量中约34%是因为降水增加所致,66%是因为温度升高导致冰川消融加剧所致.

英文摘要：

The conceptual semi-distributed rainfall-runoff model,HBV,was applied to simulate the daily runoff of Dongkemadi River basin in the headwaters of Yangtze River,to examine the applicability of this well-known model in glacier-covered basin on the Tibetan Plateau.Daily air temperature and precipitation of 2004/2005 and 2006/2007,as input variables,and discharge was used for calibration.The hydro-meteorological data of 2005/2006 and 2007/2008 was used for validation.The simulated results show that during the calibration period,Nash-Sutcliffe coefficient（Reff） is 0.81 and 0.75,respectively;during the validation period,Reff is 0.73 and 0.67.In this simulation experiment,the simulated daily runoff does not fit very well with the observed data.However,the Reff reaches 0.94 when simulating the monthly runoff and the bias is only 6% when simulating the annual runoff.It clearly shows that the simulated monthly and annual runoff is more trustable than the simulated daily runoff.Then,using the daily temperature and precipitation data（1955—2008） of four national meteorological stations near the Dongkemadi River basin,the Drab＇s daily temperature from 1955 to 2008 was gained by polynomial interpolation,the daily precipitation was got by using the combined method of precipitation gradient and inverse distance weighting.Using the interpolated meteorological data as the driving data,this study reconstructed the daily runoff from 1955 to 2008 by HBV model.It is found that from 1955 to 2008 the runoff depth increased with a rate of 5.61 mm·a-1,and the glacier mass balance loss rate was-136.0 mm·a-1.Comprehensively analyzing the temperature,precipitation and runoff,it is speculated that the aggravating glacier ablation caused by increasing air temperature was most likely the main driving force for the runoff increase in the basin,accounting for about 66%.