1976-2010年祁连山中段岗格尔肖合力雪山冰川退缩和气候变化的关系研究

运用最大似然监督分类法和比值阈值法（TM3/TM5）结合目视解译方法,从1976、1990、2001和2010的MSS、TM、ETM影像中提取了岗格尔肖合力雪山四个时段的冰川边界,并结合距其较近的托勒、野牛沟、祁连、德令哈和刚察5个气象站点1960-2010年年总降水量数据和年平均气温数据进行了分析,得到如下结论：1）...

Climate change and glacier retreat in Ganggeexiaoheli,middle Qilian Mountains using remote sensing data,1976-2010

This paper presents an analysis of precipitation and temperature trends and glacier changes in Ganggeexiaoheli of Middle Qilian Mountains.Trend analysis for the period from 1960 to 2010 at five selected meteorological stations showed a pronounced temperature increase.For precipitation,there was a small increase on average,but no clear trend.The glacier outlines of 1976 were delineated using maximum likelihood classification from a Landsat MSS Scene then improved manually.The glacier outlines of 1990,2001 and 2010 were delineated in a semi-automated way using band TM3/TM5 ratio images of Landsat TM or ETM scenes.The decrease in glacier extent was 68.60% between 1976 and 2010 because of temperature rising and a rapid and accelerating shrinkage in the last decade was detected,which was consistent with the temperature increase in the same period.The glacier retreat was not homogeneous.128 of 132 glaciers of 1976 with area less than 3 km2 disappeared and the other four glaciers with area larger than 3 km2 were split into 34 small glaciers in 2010.Shrinkage rate of glaciers with low elevation was higher than that with high elevation,which indicated that glaciers with low elevation were much more sensitive to climate changes.Overall,south,southeast and southwest facing glaciers shrank mostly,which indicated that glaciers on those aspects were more sensitive to climate changes in this region.Given the temperature increase in the future,based on IPCC,the glaciers in this region will continue to retreat.In the short-term,as glaciers retreat and lose mass,they add to a temporary increase in runoff,thereafter their contribution to runoff will be decrease,thereby raising serious sustainability concerns.