三个时期青藏高原冰川补给型湖泊的变化

Changes of Glacier-fed Lakes in Tibetan Plateau for Three Periods

根据美国国家冰雪数据中心（NSIDC）发布的2012年全球冰川分布数据等资料,选取青藏高原冰川分布较集中的地区作为研究区,利用1995年、2005年和2015年3个时期Landsat TM/ETM＋/OLI遥感影像数据和研究区附近气象站的气象资料,综合利用＂3S＂技术和统计分析方法等,研究3个时期研究区内湖泊面积与数量及其变化,从气候要素变化与冰川退缩角度分析其驱动因素。研究结果表明,3个时期研究区冰川补给型湖泊整体呈扩张态势,1995年、2005年和2015年的冰川补给型湖泊面积分别为10700.5 km^2、11910.7 km^2和12518.3 km^2;与1995年相比,2005年的湖泊数量增加了2 041个,与2005年相比,2015年的湖泊数量增加了21个;分布在研究区各流域中的冰川补给型湖泊变化状况不同,分布在羌塘高原上的湖泊扩张幅度大,分布在柴达木盆地中的湖泊呈缓慢扩张态势,分布在研究区南部雅鲁藏布江流域中的湖泊相对稳定,还有一些湖泊在萎缩。随着海拔的增加,研究区中的湖泊数量和面积都呈现类似正态分布的特征。1995-2015年期间,冰川退缩和气温上升是导致青藏高原冰川补给型湖泊面积和数量变化的主要原因。

Based on the global glacier distribution product released by NSIDC in 2012, several intense glacier regions in Tibetan Plateau were determined as research areas. The number and areas of lakes for three periods were derived fromLandsat TM/ETM＋/OLI acquired in 1995, 2005 and 2015. Meteorological data and the information of glacier shrinkage around the study area were collected, and the driving factors of changes of number and areas of the lakes were analyzed in Arc GIS software. The results indicated that both number and areas of the lakes in the study area had increased during 3 periods. The areas of the lakes in 1995, 2005 and 2015 were 10700.5 km^2, 11910.7 km^2 and 12518.3 km^2, respectively. The number of the lakes increased by 2041 lakes from 1995 to 2005, and by 21 lakes appeared during 2005-2015. However, spatial variation of glacierfed lakes area differed obviously among sub-basins across the Tibet Plateau. The areas of the lakes in the Qiangtang Plateau and Qaidam Basin increased significantly and slightly respectively. The area of the lakes in southern Brahmaputra River Basin was relatively stable and some lakes even presented a shrinking trend.With the increasing of altitude, the number and areas of the lakes in the study area were similar to the normal distribution. During the period 1995 to 2015, the glaciers in Tibet Plateau had a serious trend of shrinkage,and the increasing air temperature and glacier shrinkage were the main reasons for the spatiotemporal variations of number and areas of the lakes.