关键词: 遥感, 冰川变化, 区域差异性, 分形, 祁连山西段

Abstract: Mountain glaciers are sensitive climate indicators and thus subject to monitoring of environmental and climate changes. Furthermore，glacier runoff is the major contributor to water resources that are used to support the sustainable development of the environment，industry，and agriculture in arid region. Most researches of glacier changes in the Qilian Mountains are focused on the East and Middle of Qilian Mountains. Research on large-scale and long-time glacier fluctuations in the West Qilian Mountain region is limited despite the fact that the glaciers in this region provide important water resources for local economic development. During the past decades，glaciers in the Western Qilian Mountains have experienced rapid shrinking primarily due to climatic warming. Impacts of the glaciers shrinkage on water resources have drawn wide attention. Taking this into account，glaciers in the Daxue Mountain and Danghenan Mountain were selected to study in this paper. Based on 1: 50 000 topographic maps in 1957/1966（5 in 1957，14 in 1966），satellite images （Landsat TM in 1994，ASTER in 2000 and SPOT5 in 2010） and digital elevation model （DEM），the selected glaciers was extracted by using the remote sensing image processing and analyzing method，and the changes of glaciers in the study area were analyzed under the support of the geographic information systems technology. The results indicate that from 1957/1966 to 2010，the total area and ice volume for the investigated glaciers in the study area have reduced by 17.21% and 24.1%. It is also found that from 1957 to 2010，the total area and ice volume for the investigated glaciers （196） in the Daxue Mountain have reduced by 16.03% （0.30%/a） and 22.4%，with a mean reduction of 0.133 km2 for the individual glacier，the glaciers retreated by 258 m （3.4 m/a）. From 1966 to 2010，the total area and ice volume for the investigated glaciers （281） in the Danghenan Mountain have reduced by 18.32%（0.42%/a）and 25.7%，with a mean reduction of 0.111 km2 for the individual glacier，the glaciers retreated by 159 m（3.6 m/a）. The rate of glacier retreat on south slopes was faster than that on the north slopes. The area of glaciers in South and North slope of Daxue Mountain have reduced by 22.82% and 15.51%，the area of glaciers in South and North slope of Danghenan Mountain have reduced by 22.39% and 16.76%，respectively. By analyzing the general trend of climatic change of the study area，it was found that rapidly rising air temperature is likely to be the major factor causing the shrinkage of the glaciers in the study area. Compared with other glaciers in the Eastern and Middle Qilian Mountains，glaciers in the western Qilian Mountains appeared to be decreasing more slowly. The differences of glacier changes in the Eastern，Middle and Western Qilian Mountains are mainly due to the combination of climatic conditions and glacier sizes.

Key words: Remote sensing, Glacier change, Regional differences, Fractal, Western Qilian Mountains