近30年珠穆朗玛峰国家自然保护区冰川变化的遥感监测

Monitoring Glacier Change Based on Remote Sensing in the Mt. Qomolangma National Nature Preserve,1976-2006

利用1976、1988和2006年的3期陆地卫星遥感数据,采用面向对象的解译方法并结合专家知识分类规则自动提取珠穆朗玛峰国家自然保护区(以下简称珠峰保护区)3个时期的冰川信息,并利用遥感、地理信息系统和图谱的方法对冰川时空分布特征和变化及其原因与不确定性进行了分析。结果如下:(1)2006年珠峰保护区内冰川面积为2710.17±0.011km2,为研究区总面积的7.41%,主要分布在研究区南部海拔4700～6800m的高山区;(2)1976-2006年,珠峰保护区冰川持续退缩明显,总面积减少501.91±0.035km2,冰湖扩张迅速(净增加36.88±0.035km2);研究区南坡子流域冰川退缩率(16.79%)高于北坡子流域(14.40%);珠峰保护区冰川以退缩为主,退缩冰川主要分布于海拔4700～6400m,退缩区上限海拔为6600～6700m;(3)1976年以来,气温显著上升和降水减少是冰川退缩的关键因素。

Based on Landsat TM （/MSS） images in 1976, 1988 and 2006, glacier extents in the three periods in the Mt. Qomolangma National Nature Preserve （QNNP） have been automatically derived by object-oriented image interpretation method combined with expert knowledge rules and field surveys. Spatial-temporal distribution and changes of glaciers are analyzed with the aid of GIS, RS and Tupu method. Results show that （1） The glacial area at QNNP in 2006, located mainly in the southern high mountain region with elevations of 4700-6800 m, amounted to 2710.17±0.011 km^2, about 7.41% of the whole study area; （2） During 1976-2006, glaciers tended to shrink significantly by 501.91±0.035 km^2 in total, and glacial lakes expanded rapidly with an increase of 36.88±0.035 km^2; the rate of glacier retreat is higher in sub-basins on the southern slope （16.79%） of Himalayas than those on the northern slope （14.40%）; （3） Most glaciers retreated, mainly occurred at elevations of 4700-6400 m, and the estimated upper limit of retreated zone is between 6600 m and 6700 m; （4） The temperature rise along with precipitation decrease is considered to be the key factor of glacier retreat in the region.