近50年黑河流域的冰川变化遥感分析

黑河流域作为中国西北地区第二大内陆流域，其景观类型完整、流域规模适中、社会生态环境问题典型，已成为寒区、旱区水文与水资源研究的热点地区。本研究结合1：5 万地形图、Landsat TM/ETM+遥感影像及数字高程模型数据，运用面向对象的图像信息自动提取方法，建立冰川信息提取知识规则，对近50 年黑河流域的冰川变化进行遥感分析。结果表明：（1）20 世纪60 年代黑河流域内的967 条冰川到2010 年左右，减少为800 条冰川，减少数量明显；冰川面积由361.69 km²退缩为231.17 km²，共减少130.51 km²，退缩率为36.08%，平均每条冰川面积退缩0.14 km²。（2）黑河流域冰川分布及变化存在显著的区域差异性，黑河冰川退缩率比北大河大16%左右；冰川末端主要分布在4300~4400 m、4400~4500 m和4500~4600 m海拔区间内。（3）与西部其他山地冰川相比，黑河流域冰川退缩率较高。（4）根据流域内6 个气象站资料分析表明，降水增加对冰川的补给无法弥补气温上升导致的冰川消融所带来的物质损失，是黑河流域冰川普遍萎缩的关键因素。

RS analysis of glaciers change in the Heihe River Basin in the last 50 years

The Heihe River Basin is the second largest inland river basin in Northwest China and it is also a hotspot in arid hydrology, water resources and other aspects of researches in cold regions. In addition, the Heihe River Basin has complete landscape, moderate watershed size, and typical social ecological environmental problems. So far, there has been no detailed assessment of glaciers change information of the whole river basin. Therefore, it is urgent to conduct studies on the assessment of glacial change in this region. Landsat TM/ETM+ remote sensing images, digital elevation model data and 1:50,000 topographic map data were used in this research. Through integrated computer automatic interpretation and visual interpretation methods, the object-oriented image feature extraction method was applied to extract glacier information. Glaciers change data were derived from spatial analysis, and the glacier variation and its response to climate change in the period 1956/63-2007/11 were also analyzed. The results are shown in the following. (1) In the period 1956/63-2007/11, the Heihe River Basin's glaciers had an evident retreat trend, the total area of glaciers decreased from 361.69 km² to 231.17 km², at a rate of 36.08%, and average single glacier area decreased by 0.14 km²; the total number of glaciers decreased from 967 to 800. (2) Glaciers in this basin are mainly distributed at elevations of 4300-4400 m, 4400-4500 m and 4500-4600 m; there are significant differences in glacial distribution and glacial change. (3) Compared with other western mountain glaciers, glaciers retreat in the Heihe River Basin had a higher rate. (4) By analyzing the meteorological data at six weather stations from 1960 to 2010, it is found that the mean annual temperature increased significantly and the annual precipitation also showed an increasing trend. It is concluded that glacier shrinkage is closely related with temperature rising. Besides, glacier melting caused by rising temperatures is greater than glacier mass supply by increased precipitation to some extent.