西藏玛旁雍错流域湖泊面积变化及成因分析

利用1975年地形图、1990年、1999-2009年TM卫星遥感影像和近35 a(1975-2009年)气温、降水、积雪日数、蒸发量等气候资料，分析研究了位于西藏阿里地区南部普兰县境内玛旁雍错、拉昂错湖泊面积变化对气候变化的响应。结果表明：在过去35 a里玛旁雍错、拉昂错面积先减少后增加，总体呈减小趋势，到2009年玛旁雍错面积为415.44 km²，拉昂错面积为261.36 km²。与1975年相比2个湖泊面积分别减少了1.56 km²和11.01 km²；受气候变暖的影响，流域附近的冰川面积也在加速退缩。对1975-2009年普兰县气象资料统计分析可知，降水量减少是导致湖泊面积缩小的主要原因，蒸发量不显著的增加及雪冰消融也是近几年湖泊面积波动变化的原因之一。

Study on the Change of Lake Area and Its Causes in the Mapangyong Co Basin in Tibet

This paper investigated the change of area of the Mapangyong Co Lake and Laang Co Lake in Pulan County, Tibet Autonomous Region and its response to climate change based on the topographic map in 1975, TM satellite remote sensing data in the years of 1990, 1999-2009 and climatic data including air temperature, precipitation, snow cover days, evaporation, etc. in recent 35 years (1975-2009). Results indicate that the areas of both the Mapangyong Co Lake and Laang Co Lake were reduced at first and then enlarged. Holistically, the areas of these two lakes were in a reduction. Areas of the Mapangyong Co Lake and Laang Co Lake were reduced to 415.44 km² and 261.36 km² in 2009, and they were reduced by 1.56 km² and 11.01 km^2, respectively. Furthermore, the areas of modern glaciers near the lakes were also reduced due to climate warming. According to the statistical results of meteorological data in Pulan County during the period of 1975-2009, the decrease of precipitation was the dominant factor resulting in the reduction of lake areas, and then the slight increase of evaporation and the melt of modern glaciers.