祁连山北大河流域冰川变化遥感监测

基于1956年地形图和2003年ASTER影像数据，在RS和GIS技术支持下，确定了1956年和2003年的冰川边界，对祁连山北大河流域冰川近47 a来的变化进行了研究。结果表明：该流域372条冰川面积在47 a间共减小了33.56 km²，平均每条减小0.09 km²，变化率-15.42%，冰川末端累计退缩51 015 m。分析显示，小冰川比大冰川消融的更快。对研究区附近气象站近年来的年平均气温、夏季平均气温和年降水量进行分析，认为气温升高是北大河流域冰川快速萎缩的主要原因。与中国西部其他冰川进行对比研究发现，北大河流域冰川消融速率比新疆要快，但较黑河流域及其他子流域要慢，初步推测是由冰川所在区域的气候及冰川自身因素共同作用的结果。

RS-based Monitoring of Glacier Change in the Beidahe River Basin in the Qilian Mountains

In this paper,the change of glaciers in the Beidahe River Basin in the Qilian Mountains in recent 47 years was studied using the topographic map in 1956 and the ASTER image data in 2003 so as to ascertain the glacial boundaries in these two years under the support of RS and GIS means.The results show that area of the 372 glaciers in the basin was reduced by 33.56 km2 in recent 47 years,0.09 km2 per glacier in average,the change rate was-15.42%,and the total shrinkage of the glacier terminals was 51 015 m.The analyzed results revealed that the melting of small glaciers was faster than that of large ones.After comparing and analyzing the data of average annual temperature and summer temperature as well as annual precipitation,it was considered that the significant temperature increase was the main cause resulting in the rapid shrinkage of glaciers in the Beidahe River Basin.After carrying out a comparative study on glacier shrinkage in west China,it was found that the glacial melting rate in the Beidahe River Basin was higher than that in north Xinjiang but lower than that in the Heihe River Basin and other distributary basins.It was conferred preliminarily that the shrinkage of glaciers might be jointly caused by climate change and the factors of glaciers themselves.