近20 a来西藏朋曲流域冰湖变化及潜在溃决冰湖分析

全球气候变暖, 青藏高原冰川普遍处于退缩趋势, 由此引发的冰湖溃决洪水的灾害也随之增加. 通过对2000/2001年度卫星遥感数据解译结果和1987年国际联合考察的朋曲流域冰湖溃决洪水结果的分析, 研究了近20 a来朋曲流域内冰湖的变化. 结果显示, 该流域中的冰湖数量有减少, 但冰湖的面积却在增加, 这是同期全球气候变暖的结果. 在提供了冰湖编目数据的基础上, 识别了有潜在危险的冰湖, 为冰湖溃决洪水早期预警系统提供了科学依据.

Glacial Lakes Variation and the Potentially Dangerous Glacial Lakes in the Pumqu Basin of Tibet during the Last Two Decades

Along with glacier retreating due to global warming, more and more meltwater cumulates in glacial lakes, resulting in expansion of lake surface. Rapid accumulation of water in glacial lakes, particularly in those lakes adjacent to retreating glaciers, can lead to a sudden outburst of the unstable dams in front of the lakes. The glacial lake outburst flood (GLOF) often has catastrophic effect on downstream regions. The GLOF causes many dangers to local people, as well as to houses, bridges, fields, forests and roads. The lakes at risk are situated in remote and inaccessible areas. Remote sensing provides a feasible method to monitor these glacial lakes. Satellite images (ASTER) acquired in 2000/2001 were interpreted and compared with the report of the First Expedition to Glaciers and Glacier lakes in the Pumqu and Poiqu River Basins, Xizang (Tibet), China. The final results have shown that there are 225 glacial lakes with a total area of 1,062 km+2, and there are 24 glacial lakes were identified as the potentially dangerous lakes in the Pumqu basin. It provides the basic information for GLOF mitigation measures, as well as for their monitoring and establishing an early warning system.