关键词: 青藏高原, 冰川变化, RS, GIS

Abstract: Glaciers on the Xizang (Tibetan) plateau play an important role in the earth’s climatic system. Regular surveys of glacier change is almost impossible in some areas of the region, and the use of remote sensing techniques is at present the primary, and in may places the only, means of measurement. GIS provides an efficient tool to analyze the status and the changes of glaciers. In this study, we use 1973～1974 serial RBV, MSS and TM Landsat data and GIS to construct glacier maps and to measure glacier changes for the Bukatage Peak located in the middle section of the Kunlun Mountains. Between 15 and 20 ground control points were selected from topographic maps and identified on each image. The root mean square error (rms) of an independent set of points was selected and used to assess the accuracy of coregistration. The maximum verification error from coregistration of all images was 53 m in the X and 67 m in the Y direction. The details of glacier change such as the velocities of glacier movement at different times were obtained by using GIS tools, based on the results of the serial images’ coregistration, classification, vector analysis and calculation. The result shows that there was no significant change in the study area as a whole, but the northern glaciers advanced while the southern glasiers retreated at the velocity of between 50～105 ma-1. Climatic record for the area shows that both temperature and precipitation had a rising trend from the mid 1950s to the late 1980s. This study suggests that the southern cirque/valley glaciers, especially the bukatage Glacier, responded more rapidly to temperature than precipitation change because of their small areal extent and volume and their south slope positions where more powerful solar radiation occurs. Because of emission from surrounding slopes, the valley bottoms receive more thermal radiation than the unobstructed areas. On the other hand, the northern glaciers, especially the West Bukatage Glacier, are larger in size and receive less solar radiation and thus are less affected by temperature than by precipitation. The northern glaciers show an advancing trend because precipitation, mainly snowfall, increased. The deficiencies of this method and the problem areas for future research are presented in the final section of the paper.

Key words: glacier change, tibetan plateau, remote sensing, geographic, information system