玉龙喀什河源区32年来冰川变化遥感监测

Glacier Changes at the Head of Yurungkax River in the West Kunlun Mountains in the Past 32 Years

根据航空相片、地形图、遥感影像数据分析了玉龙喀什河源区的冰川变化,结果表明,1970～2001年本区冰川总体上以稳定冰川的数量占多数,但由于部分冰川的退缩使得整个研究区的冰川表现为萎缩的趋势.1970～1989年冰川规模有扩大的趋势,冰川面积、储量分别增加了1.4 km2、0.4781 km3,约占1970年研究区相应总量的0.12%、0.19%;而1989～2001年的冰川面积、储量分别比1970年减少了0.5%、0.4%,是西北干旱区冰川面积变化幅度最小的区域.分析认为该区域1970～1989年冰川扩大可能与该地区的冰川对20世纪60年代末温度降低、降水量增加有10～20年滞后响应有关;1989～2001年冰川退缩,主要受温度快速上升影响,而丰富的降水对冰川退缩起到缓冲的作用.

Recent studies indicate that widespread wastage of glaciers in western China has happened since the late 1970s, but diverse places under different climate settings have marked regional discrepancy as to the amplitude in glacier shrinkages. In the present study, we investigate the changes of glaciers at the head of Yurungkax river (centered at 35o40'N, 81oE) in the heavily glaciated West Kunlun Mts. by using aerial photos (1970), Landsat TM (1989) and ETM+ (2001) imageries. A comparative analysis performed for glacier length/area variations since 1970 in the West Kunlun Mts. shows that the prevailing characteristic of glacier variation is ice wastage, however, changes in glacier area are very small in this region. Results indicate that a small enlargement of ice extent during 1970-1989 was followed by a reduction of over 0.5% during 1989-2001. It concludes that the enlargement of glaciers during 1970-1989 might be caused by the decrease in air temperature and the increase in precipitation during the 1960s and that glacier shrinkage during 1989-2001 might be reaction to increase in air temperature, but abundant precipitation acts as a role of buffer in variations of surface mass balance of glaciers in the research region.