天山奎屯哈希勒根51号冰川变化及其对气候的响应

Variation of Haxilegen No. 51 Glacier at the Headwater of Kuytun River in Tianshan Mountains and Its Response to Climate Change

哈希勒根51号冰川位于新疆奎屯市以南的天山依连哈比尔尕山北坡,即奎屯河上游支流哈希勒根河源区。继1998年对冰川末端和运动速度的首次观测之后,相继开展了多次重复测量,完成了冰川面积测量和首次雷达厚度测量。结合冰川实测资料和已有相关研究,对自20世纪60年代以来的变化特征进行了详细分析,结果表明:1964—2006年哈希勒根51号冰川面积共减小了0.123 km2,年平均退缩率约为0.19%,相比低于天山地区的整体水平(0.31%)。冰川末端累计退缩84.51 m,年平均退缩率为2.01 m。对于冰川运动速度,1999—2006年整体偏低,各流速点的年际变化较小,且略微有下降的趋势;7 a间物质平衡年际变化较小,整体表现出沿海拔高度增加而增加的趋势。1964—2010年冰川厚度减薄了约10 m,年均变化率约为0.22 m。与天山乌鲁木齐河源1号冰川相比,整体消融趋势稍弱。

The Haxilegen No. 51 Glacier is located on the northern slope of Eren Habirga Mountains in the Tianshan Mountains,the headwater of the Haxilegen River which is a tributary at the upper reaches of the Kuytun River.In order to measure and research the change of the Haxilegen No. 51 Glacier,we established 26 rods on the glacier in August 1999,with 2 control points around the glacier and 3 control points in the glacier terminus for measuring the change. The changes in the glacial terminus and glacial surface velocity from 1999 to 2006 were measured by using GPS and traditional technique. The results reveal that the glacial area has reduced by 0. 123 km^2during1964- 2006,by 0. 083 km^2 and 0. 040 km^2 during the periods of 1964- 2000 and 2000- 2006,respectively. That is,the reduction of glacial area became more and more marked,and the annual percentage of area changes（ APAC） for the glacier was 0. 19%,lower than an average of other glacier＇s areas in the Tianshan Mountains. The glacier terminus has retreated for about 84. 51 m,and the average annual shrinkage was 2. 01 m. The surface velocity of the glacier in 1999- 2006 was slower. The mass balance of the glacier increased with the rise of the elevation,but the inter-annual variation was smaller during 7 years. During the period of 1964- 2010,the thickness of Haxilegen No. 51 Glacier thinned by about 10 m,with an average annual rate of 0. 22 m. Comparison between the No. 1Glacier at the headwater of the Urumqi River and Haxilegen No. 51 Glacier at the headwater of Kuytun River in recent decades showed that the tendency of Haxilegen No. 51 Glacier melt was weaker as a whole.