1980-2010年西藏波密地区典型冰川变化特征及其对气候变化的响应

运用遥感(RS)与地理信息系统(GIS)技术, 结合波密县1960-2010年气象数据, 分析了西藏波密地区冰川的主要分布特征和典型大冰川1980-2010年的时空变化. 结果显示: 波密县共有冰川数量2 040条, 总面积为4 382.5 km², 其中, 分布在海拔4 000~6 000 m的高山冰川总面积达4 086 km², 占冰川总面积的93.2%; 南坡分布冰川1 504条, 面积3 180.04 km², 分别占波密冰川总量的73.73%和72.56%, 而北坡占还不到三分之一. 提取1980、 1990、 2000和2010年4期面积大于20 km²的24条大冰川面积进行对比分析, 1980-2010年间波密县大冰川面积总体呈减小趋势, 由1980年的1 592.78 km²退缩至2010年1 567.04 km², 共退缩了25.74 km²; 其中, 1980-1990年冰川变化贡献最大, 冰川面积退缩了16.62 km², 占冰川总面积退缩量的64.6%. 波密县气象站数据显示, 50 a来冰川退缩主要受温度持续上升的影响, 降水量变化对冰川变化影响不大.

Variation of Glaciers and Its Response to Climate Change in Bomi County of Tibet Autonomous Region in 1980-2010

By applying remote sensing (RS) and geographic information system (GIS) technology, combined with Bomi meteorological data of 1960-2010, glaciers distribution characteristics and spatial and temporal variations of typical large glaciers during 1980-2010 in region of Bomi County, Tibetan Plateau are analyzed. The results show that there are a total number of 2,040 glaciers with a total area of 4 382.5 km² in region of Bomi County, glacier total area of 4 086 km² located at an altitude of 4 000~6 000 m, accounting for 93.2% of the total area of the glacier. There are 1 504 glaciers with an area of 3 180.04 km² distributed on the southern slope, accounting for 73.73% of total glacier number and 72.56% of total glacier area respectively, while accounting for less than one-third ones on the north slope. Extraction four periods of 1980, 1990, 2000 and 2010 glacier area of the 24 large glaciers with greater than 20 km² were analyzed. The all 24 greater glaciers in Bomi County have a decreasing trend from 1980 to 2010, a glacier area of 1 592.78 km² in 1980 retreat to one of 1 567.04 km² in 2010, a total retreated area of 25.74 km²; which glacier change of 1980 to 1990 contributed the largest retreated area of 16.62 km², accounting for a total area of glacier retreat amount of 64.6%. Records data of Bomi Meteorological Station show that there has been a continuous temperature rise, especially after 1980, which might seriously cause the glacier shrinkage, and changes in precipitation have less impacting on the glacier variation.