近40年来冷龙岭地区冰川退缩和气候变化的关系

运用比值阈值法(TM3/TM5)结合目视解译,从1973年、1999年和2010年3个时段的MSS、ETM、TM影像中提取了祁连山东段冷龙岭地区冰川的边界,并对距其较近的门源、乌鞘岭、武威和永昌4个气象站点1961—2010年的气象数据以及冰川区的气象数据进行了分析,结果表明:(1)37a来,冰川处在持续退缩状态;近10a来,冰川消融速度加快;南坡退缩较快,北坡退缩较慢,其它坡向介于二者之间;(2)该区增温趋势较明显;该区的降水虽有少量增加,但趋势却很不明显;(3)37a来,冰川退缩的主要原因是气温的升高;近10a来,冰川加速消融反映了20世纪90年代末以来的气温变化特征;南坡冰川对气候变化的反应较敏感。

Relationship between Climate Change and Glacier Retreat over the Last 40 Years in Lenglongling Range of Eastern Qilian Mountains

The glacier outlines of the year 1973 were delineated manually from a Landsat MSS scene.The glacier outlines of the year 1999 and 2010 were delineated in a semi-automated way using band TM3/TM5 ratio images of Landsat ETM or TM scenes.The decrease in glacier extent was 56.21% between 1973 and 2010 because of rise of temperature,and a rapid and accelerating shrinkage in the last decade was detected,which was consistent with the temperature increase from 1997.Overall,south facing glaciers shrank most,which indicated that glaciers on this aspect 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.With glaciers retreat and mass loss,their contribution to runoff will decrease,thereby serious sustainability concerns will be raised.