1973-2010年阿尔金山冰川变化

利用1973 年MSS、1999 年ETM+和2010 年TM遥感影像资料,通过遥感图像处理和GIS技术,提取了阿尔金山地区三个时期的冰川信息,同时结合周边气象资料进行分析。结果表明:① 1973-2010 年,研究区冰川面积从347.99 km² 减少到293.77 km²,退缩了54.22km²,占1973 年冰川总面积的15.58%,年均退缩速率为0.42%·a^-1。近10 年来冰川退缩尤为剧烈,年均退缩速率达到0.58%·a^-1;② 研究区东段冰川退缩速率快于中段和西段;③ 冰川规模越小,退缩越明显;④ 研究区东坡冰川的面积退缩率最大,北坡次之,东南坡最小;⑤ 气温升高和降水在波动中变化不大是造成研究区冰川退缩的主要原因;⑥ 通过分形理论对研究区冰川空间结构特征进行分析,预计研究区冰川今后的消融速率仍将处于较高状态。

Glacier variation in the Altun Mountains from 1973 to 2010

Based on the 1973 Landsat MSS, 1999 Landsat ETM+ and 2010 Landsat remote sensing image data, the glacier information of three periods in the study area was extracted by using the remote sensing image processing and GIS. Meanwhile, the meteorological data were analyzed in this paper. The results showed that: (1) During 1973-2010, the total glacier area in the study area decreased from 347.99 km² to 293.77 km²; the overall loss was 54.22 km², or 15.58% of the whole glacier area in 1973; the annual retreat rate was 0.42%·a^-1. The shrinkage rate of glaciers was accelerated during 1999-2010, and the annual retreat rate was 0.58%·a^-1. (2) The retreat rate of eastern Altun glaciers was higher than that of central and western Altun Mountains. In recent 37 years, the glacier area decreased by 19.10%, 14.66% and 15.17% in eastern, central and western Altun, respectively. (3) Small glaciers receded faster than large glaciers. (4) The glaciers facing east had the highest retreat rate, followed by those facing north, while the retreat rate of the glacier facing southeast was the lowest. (5) In recent 37 years, warming trend in the study area was obvious, while precipitation changed little. Temperature increase was the main reason for the glacier retreat in this region. (6) The characteristics of spatial structure for the glaciers were analyzed based on the fractal theory. It is shown that the glaciers with an area of less than 0.1 km² had the most unstable spatial structure, and they were most prone to ablation, while the glaciers with an area ranging from 0.1 km² to 0.5 km² had the strongest sensitivity to climate change, and the glaciers with a range of 1.0-5.0 km² will continue to be predominant in the glacier area change in the future. The research predicts that the ablation rate of glaciers in the study area will remain high due to global warming.