近40年东帕米尔高原冰川变化及其对气候的响应

Response of glacier variations in the eastern Pamirs plateau to climate change,during the last 40 years

以1972年、2000年和2011年Landsat Mss/TM/ETM+遥感影像处理和目视解译结果为依据,分析了东帕米尔高原1972～2011年冰川变化情况。结果表明:1972～2011年研究区冰川面积、储量减少了103.97km2和8.04km3,分别占1972年冰川总面积、储量的5.79%和6.69%。但冰川退缩具有不等速性,1972～2000年面积、储量年退缩百分比分别为0.182%和0.212%,而2000～2011年仅为0.045%和0.048%。对流域内两个气象站气候资料的分析表明:1972～2000年冰川快速退缩与1970～1980年气温偏高而降水偏少有关,2000～2011年冰川退缩趋缓与80年代以后相对低温和湿润气候相关。

The satellite images （Landsat Mss/TM/ETM ＋ ） from 1972 to 2011 were used to map the surface area of glaciers in this region through a process of manual digitizing on a false color composite of bands 5,4,3 （red, green, blue）. The results indicate that the glacier area and volume over the eastern Pamirs plateau shrunk by 5. 79% and 6.69% respectively in the last 40 years. The rate of the glacier area decrease was 0. 182%/a over the interval 1972-2000,but decreased by about 1/4（0.045%/a）from 2000 to 2011 ,which indicated a slow down of glacier retreat in recent decades. In the same way, the volume of the eastern Pamirs glaciers was reduced with the rates of 0.212%/a from 1972 to 2000,0.048 %/a during 2000 - 2010, respectively. Glacier changes in eastern Pamirs showed a significant response to increasing summer temperatures. Analysis of the climate records of the past 40 years from Kashi and Tashikuergan meteorological station also showed the large shrinkage of eastern Pamirs glaciers from 1972 to 2000, which can be attributed to warm and dry climatic events during 1970 - 1980. The increase of glaciers from 2000 to 2010 can be attribute to cold and moist climatic events during 1980 - 1996.