西藏东南部米堆冰湖面积和水量变化及其对溃决灾害发生的影响  

Study on the Variations of Lake Area & Volume and Their Effect on the Occurrence of Outburst of MUDUI Glacier Lake in Southeastern Tibet

作　　者：杨瑞敏[1,2] 朱立平[1] 王永杰[1] 除多[3] 

机构地区：[1]中国科学院青藏高原研究所青藏高原环境变化与地表过程重点实验室,北京100085 [2]中国科学院研究生院,北京100049 [3]西藏高原大气环境科学研究所,拉萨850000

出　　处：《地理科学进展》2012年第9期1133-1140,共8页Progress in Geography

基　　金：国家自然科学基金重点项目(41130529);中科院创新方向项目(KZCX2-EW-113);中科院青藏高原环境变化与地表过程重点实验室开放课题(2010-7)

摘　　要：冰湖溃决灾害是青藏高原地区主要的灾害之一。详细了解冰湖的面积和水量变化及其原因,有助于更准确地确定其溃决的可能性和产生破坏的程度和范围。米堆冰湖为一个典型的冰碛物阻塞冰湖,1988年7月15日曾发生溃决。本研究利用1980年1∶5万地形图和DEM、1988年TM影像、2001年IKONOS影像以及2001、2007、2009、2010年ALOS影像,提取冰湖溃决前后的面积变化,结合野外实地测得的冰湖水深,获得冰湖不同时期的水量及其变化。同时,利用自动水位计,监测湖泊相对水深的变化及其原因。结果显示,米堆溃决前面积达到64×104m2,水量为699×104m3,溃决使得601.83×104m3的水量溃出,水位下降了17.18 m,但溃决口并未达到冰湖最低处,溃决后仍有97.17×104m3的水量。近年来,气温升高融水增加使得冰湖面积和水量不断增加,按照目前的水量增加速率,冰湖再次发生溃决的可能性较小,而在由于其他原因使得冰湖发生堵塞或大量外来物质(冰川断裂、滑坡等)填充进冰湖时,可能导致冰湖水位急剧上升,再次发生溃决。Glacial lake outburst is one of the main hazards on the Tibetan Plateau. It is very important to understand the detailed information of variations and reasons of glacial lake area ＆ volume for evaluating the possibility of glacial lake outburst and its damage degree. Midui Glacial Lake is a typical moraine-dammed lake, which had an outburst on July 15th in 1988. In this study the authors extract this lake areas in different stages from the topographic map （1：5000） taken in 1980 and TM images in 1988, IKONOS in 2001, ALOS in 2001/2007/2009/ 2010. The lake volumes in different stages are calculated by using the lake areas and the bathymetric survey results. Meanwhile, the authors monitor the relative lake water level changes by using automatic water gauges. Resuits show that the area and water volume of Midui glacial lake were 64×10^4 m^2 and 699×10^4 m^3, respectively before its outburst on June 15th in 1988. There was a water loss of 601.83×10^4 m^3 due to this outburst and the relative lake level decreased by 17.18 m. However, the out flow bed was still higher than the lake bottom so that there were still 97.17 ×10^4 m^3 water volume in the lake after the outburst. In recent years, the lake area and volume have been continually increasing due to the increase of glacial melting water caused by climate warming. There is a less possibility of lake outburst according to present increasing rate of the lake area ＆ volume. However, if the outflow of the lake is blocked or a large amount of extemal materials （glacier breakdown, landslide） were filled into the lake, the lake level will rise sharply and a new outburst will occur.

关 键 词：藏东南 米堆冰湖 溃决 面积和水量 遥感 

分 类 号：P343.6[天文地球—水文科学] X43[天文地球—地球物理学]