近50a来中国阿尔泰山冰川变化——基于中国第二次冰川编目成果

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,对中国阿尔泰山冰川近50 a变化进行分析。结果表明,1960至2009年期间,中国阿尔泰山地区冰川普遍退缩,冰川数量、面积与冰储量分别减少116条、104.61 km²和6.19 km³。与中国其他山系冰川变化相比,阿尔泰山冰川面积年平均减少率最大,是冰川退缩最强烈的地区。阿尔泰山冰川在各个朝向均呈退缩趋势,其中朝北向冰川条数与面积减少大于其他朝向,朝西向冰川变化最小。2 400~2 600 m、2 600~2 800 m和3 000~3 200 m三个海拔区间冰川条数和面积均呈减少趋势,其中2 600~2 800 m冰川退缩最为显著。冰川变化呈现出区域差异性,布尔津河流域冰川数量和面积减少最多,但在其他流域冰川条数减少与面积减少并没有保持一致性,小冰川大规模退缩(或消失)是导致阿尔泰山地区冰川变化区域差异的主要原因。阿尔泰山地区冰川退缩与气候变化关系密切。对研究区4个气象台站5-9月平均气温和10-4月降水变化分析表明,自1960年代以来,阿尔泰山地区5-9月平均气温显著上升,气温上升导致的冰川消融在一定程度上抵消了固态降水增加对冰川的补给。

Glacier Change of Altay Mountain in China from 1960 to 2009 --Based on the Second Glacier Inventory of China

Glacier change of Altay Mountain in China during the past 50 years was analyzed based on the outcome of Investigation of Chinese Glacier Resources and Their Changes and result of the First Glacier Inventory of China. The results showed that glaciers had been retreating in Altay Mountain in China from 1960 to 2009. The number of decreased glaciers reached 116, the area reduced 104.61 km² and the volume loss was 6.19 km³. Compared with glacier change in other mountains in China, the annual average rate of glacier recession was the maximum in Altay Mountain where thus was the strongest region of glacier shrinkage. From the respect of glacier orientation, glaciers retreated in every direction. The maximum loss of glacier area occurred in north direction and the minimum appeared in west direction. The number and area of glaciers showed an obvious decrease tendency at altitudes of 2400-2600 m, 2600-2800 m and 3000-3200 m. The most remarkable shrinkage of glaciers occurred at an altitude of 2600-2800 m. Glacier change had a regional difference. The number and area of glacier retreat decreased most in Burqin River watershed where the glaciers were concentrated. However, there was an inconsistency between number and area reduction of glaciers in other watersheds. The recession or disappearance of a large amount of small glaciers was the main cause of regional difference of glacier change. There was a close relation between glacier recession and climate change in Altay Mountain. The average temperature from May to September and precipitation from October to April in the next year from four meteorological stations in the study area both increased. The glacier recession in this region indicated that supplies to glaciers by increases in precipitation did not compensate for ablation rate increases caused by the dramatic temperature rise during the study period.