Spatial and temporal characteristics of snow cover in typical alpine area of Tianshan Mountains

Water resources in arid regions of Northwestern China is a vital problem concerning regional coordinated development.Studies on the temporal and spatial distribution of water resources of snow and ice in these regions are of great significance.The snow cover information of 4 selected months in 2000 are acquired based on Landsat/ETM+ images and SNOMAP algorithm,which are used in analyzing spatial distribution and seasonal variation of snow cover in typical alpine area of Tianshan Mountains by combining with DEM data.The largest snow cover extent over study area is found in January within the all months studied,mainly located in southwestern and southern part of study area,which probably results from the combined action of westerly circulation and topographical features.In addition,the snow cover fraction of 4 months increase with rising elevation,but in different rate.Moreover,no distinct pattern of snow cover distribution with changing aspect is found in different months and elevation zones.