1968-2009年叶尔羌河流域冰川变化——基于第一、二次中国冰川编目数据

利用"中国冰川资源及其变化调查"项目最新冰川编目成果和中国第一次冰川编目结果, 对中国叶尔羌河流域1968-2009年冰川变化进行了分析. 结果表明:叶尔羌河流域冰川总体上处于退缩状态, 面积减少了927 km², 年平均面积减少23.2 km², 年均面积缩小比例为0.36%·a^-1, 与中国其他地区冰川退缩程度相比属于中等水平. 叶尔羌河流域不同规模冰川的退缩幅度存在差异, 小冰川大幅萎缩, 甚至消失; 规模较大的冰川相对变化幅度较小, 一些冰川出现过跃动. 从朝向分布来看, 位于南坡的冰川退缩最为严重, 而西坡较小. 冰川集中分布在海拔5 100~5 500 m和5 500~5 900 m区间, 海拔4 700~5 100 m区间的冰川面积减少最为显著. 消失冰川大多数为面积在0.2~0.5 km²的小冰川, 且朝向东北坡的冰川消失数量最多. 研究区有冰川分裂现象, 也出现了支冰川前进超覆现象, 统计表明该流域有13条冰川在前进后形成6条冰川. 1968-2009年研究区气温升高、降水增加, 总体上看, 降水增加缓解了因升温而导致的冰川退缩.

Glacier change of the Yarkant River basin from 1968 to 2009 derived from the First and Second Glacier Inventories of China

The change of glaciers in the Yarkant River basin in China from 1968-2009 were analyzed on the basis of the outcome of Investigation of Chinese Glacier Resources and Their Changes and result of the First Glacier Inventory of China.The result showed that the glacierized area in the Yarkant River basin have shrunk 927 km² at a rate of 0.36%·a^-1 as a whole. Compared with glacier changes in other mountains in China, the degree of retreat in the Yarkant River basin is in the medium range. The glacier shrinkage is different, depending on glacier size. Small glaciers shrink sharply even disappeared, but larger ones less change. In addition, some glaciers have surged. The glacier retreat has difference in direction, larger for southward ones and smaller for westward ones. Most glaciers are located in altitudes ranging from 5 100 to 5 500 m and from 5 500 to 5 900 m; most remarkably shrinking glaciers are located in altitudes ranging from 4 700 to 5 100 m. Most disappeared glaciers are small ones, 0.2-0.5 km² in area, of which most are on the northeast slopes. In the research area, most disintegrated glaciers are dendritic glaciers. In the Karakoram Mountains, due to advancing and surging, there are 13 glaciers superimposed to be 6 glaciers in the research area. The air temperature and precipitation had increased from 1968 to 2009; increase in precipitation had relieved glacier retreat under a rising temperature.