中文摘要：

根据夏季消融期成像的Landsat TM影像和2000—2009年间的MOD10A1数据资料,分析了唐古拉山区冬克玛底冰川反照率的时空变化特征.结果表明：受空间尺度效应和现有反演方法的影响,由遥感反演的反照率资料在数值上存在一定的误差,但基本上能够反映冰川反照率的时空变化特征.从空间分布上来看,该冰川反照率随海拔升高呈增大趋势,其中在平衡线附近的变化最为显著;受地形因素的影响,在同一海拔带内部也存在着较大的差异.从年内变化上来看,该冰川反照率日际变化波动较大,且具有明显的季节变化特征.从年际变化上来看,自2000年以来该冰川年均反照率的变化波动较大,总体呈微弱下降的趋势,这主要与年降雪和冰面污化程度有关;不考虑降雪对冰面反照率的影响,2000—2009年间该冰川在消融期的反照率呈逐年减小的趋势,变化速率约为-0.0083.a-1,其原因在于夏季气温的升高和冰面污化程度的加大.

英文摘要：

Based on two types albedo data from Landsat TM image acquired on August 2nd in 2007 and MODIS daily snow albedo products（MOD10A1） during the period of 2000-2009,the temporal and spatial characteristics of albedo on the Dongkemadi Glacier are analyzed in this paper.The following conclusions can be drawn： 1） Owing to the limitation of spatial heterogeneity and the current retrieving method,albedo values derived from Landsat TM images and MOD10A1 products have a certain bias（RMSE=0.046,R2=0.77 and RMSE=0.088,R2=0.68,respectively）.Nevertheless,they generally can be used for the research on spatial-temporal variations of glacier albedo.2） Spatially,albedo on the Dongkemadi Glacier increases with altitude,ranging from 0.17～0.74.Affected by topography factors,albedo at the same altitude belt appears great discrepancy,which at the zones around the snow line varies obviously most of all.3） Temporally,albedo varies greatly owing to the effect of terrain,and varies with the season change significantly as well.Seasonally,albedo is the maximum in autumn,begins to reduce in winter,reaches the minimum at the ablation period in summer（July to August）,and increases again after the summer ablation period.During the period of 2000-2009,albedo of the glacier appeared an obvious fluctuation,and decreased slowly;this trend was mainly caused by the changes of the total snowfall and the surface of the glacier.Ignoring the variation of annual snowfall,glacier albedo in the summer ablation period showed a decreasing trend during 2000-2009,with a rate of-0.0083·a-1,which was attributed to the increasing air temperature in summer and the ice surface pollution year by year.