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在近几十年气候变暖的背景下,地球上的冰川迅速消融,我国的山地冰川也发生了剧烈变化。山地冰川变化会直接或间接影响地球的生态环境及人类的生活环境,因此对山地冰川的变化进行监测至关重要。各拉丹东冰川的伸缩变化非常明显地揭示了当地乃至青藏高原和全球气候的变迁,极具科研价值。论文在总结国内外研究现状的同时结合所学知识,采用多达5个时相的陆地资源卫星以及中国冰川目录等有效资料,利用冰雪指数和监督分类方法提取冰川信息,对提取的冰川范围利用空间分析技术进行冰川变化监测。统计分析1973—1986、1986—1992、1992—2004、2004—2009年4个时间段以及1973—2009年整个36 a间的冰川前进及后退信息,并计算冰川进退变化速率,对其中5条变化较大的冰川进行详细的分析统计。结果表明:从1973年至2009年近40 a时间里,各拉丹冬地区既有退缩冰川也有前进冰川,其中冰川退缩面积为118.64 km2,前进面积为62.66 km2,冰川总体面积持续退缩。根据相关资料,近40 a来“三江源”地区气温普遍升高是导致各拉丹冬冰川总体面积持续退缩的关键因素。
In the context of recent decades of global warming, the glaciers on Earth have rapidly melted, and the mountain glaciers of our country have also undergone dramatic changes. Mountain glacier changes will directly or indirectly affect the Earth’s ecological environment and human living environment, so monitoring changes in mountain glaciers is essential. The stretching changes of the Laddan Glacier clearly reveal the changes of the local and even Tibetan Plateau and the global climate and are of great scientific value. Based on the summarization of the current research status at home and abroad, this paper combines the knowledge gained from land resources satellites with up to 5 time-series and the Chinese glacier catalog and other useful data to extract glacier information using the index of ice and snow and supervised classification, Spatial Analysis Techniques for Glacier Change Monitoring. The glacier advance and retreat information of four periods of 1973-1986, 1986-1992, 1992-2004, 2004-2009 and the entire 36-year period of 1973-2009 were statistically analyzed, and the rate of change of the glacier’s advance and retreat was calculated. Five changes Larger glaciers for detailed analysis statistics. The results show that both the retreat glacier and the advancing glacier in every region of Lardam Dong during the past 40 years from 1973 to 2009, of which glacier retreat area is 118.64 km2 and advance area is 62.66 km2, and the glacier’s overall area continues to shrink. According to relevant information, the general increase in temperature in the “Three Rivers” area in the past 40 years is the key factor that has led to the continuous retreat of the overall area of glaciers in the Lhuddan Mountains.