我国新疆玛纳斯河流域的冰川变化极大影响流域内及其周边地区的经济社会发展.使用国产高分一号(GF-1)遥感影像和Landsat8数据,分别通过基于多源数据的冰川识别方法和波段比值法获取了2013年玛纳斯河流域冰川信息,结合玛纳斯河流域第一次(1964年)、第二次(2009年)冰川编目数据与1998年、2003年TM影像冰川目视解译结果等四期的冰川边界矢量数据,对玛纳斯河流域1964-2013年50 a来的冰川变化特征进行了综合分析.研究结果显示:玛纳斯河流域冰川自2009年以来有略微增加的趋势,2013年冰川面积比2009年增加了10.25 km2,这在一定程度上抑制了长期以来冰川的快速消融;1964-2013年,玛纳斯河流域的冰川总体呈减少趋势;冰川面积从1964年的673.61 km2减少到2013年的512.07 km2,面积减少161.54 km2,减少23.98%;近50 a来,流域内冰川面积在海拔4 500 m及以上呈净增加趋势,而在海拔4 500 m以下呈净减少趋势,冰川在海拔(4 000±100)m左右退缩的速率最大,高达0.5 km2·a-1;冰川面积的减少主要体现为大量的冰舌后退和小面积冰川的快速消融,超过85%的冰川冰舌后退距离在200 m以上;该流域的冰川变化主要集中在南、北两个坡向,在南坡向上出现明显的先减少和后增加的变化趋势;1964-2013年,玛纳斯河流域的气温和降水量呈较明显的增加趋势,线性增加率分别为0.26℃·(10a)-1和16.07 mm·(10a)-1.研究结果表明气温的持续升高和降水量的增加分别是导致玛纳斯河流域冰川减少期和增加期形成的主要原因.
The glacier change in Manas River basin has a greatly effect on the economic and social development in the basin and its surrounding areas. Combined GF-1 and Landsat8 remote sensing images with four glacier inventory data of Manas River basin: the First Glacier Inventory Data (1964), the Second Inventory Data (2009) and the glacier visual interpreting results from TM (1998, 2003 ), a comprehensive analysis was done on the glacier change in the basin from 1964 to 2013 by using glacier recognition method based on multi-source data and band ratio method to obtain the glacier data in the basin in 2013. The results reveal that the Manas River glaciers have slightly increased since 2009, with glacierized area increased 10.25 km2 from 2009 to 2013, which restrained the rapid ablation of glaciers for a long time to some extent; from 1964 to 2013, the glacierized area of the Manas River basin had decreased 161.54 km2, from 673.61 km2 to 512.07 km2, with a decreasing rate of 23.98%. Over the 50 years, the glacierized area in the basin had net decreased below the altitude of 4 500 meter and had net increased above the altitude of 4 500 meter. The maximum shrinking rate of glacier might go up to 0.5 km2 · a-1 at an altitude of (4 000±100) meter. The reduction of glacierized area mainly exhibited in rapid ablation of small glaciers and in retreat of ice tongues mostly, with over 85 % of the glacier tongues retreating more than 200 meters. Glacier change in the basin was mainly concentrated on south and north aspects; there was an obvious characteristic that glacierized area turned to increase after the first reduction in the south aspect. From 1964 to 2013, air temperature and precipitation in the basin had obviously increased, with linear increasing rates of 0.26℃· (10a) -1 and 16.07 mm· (10a) -1. The research results show that rising temperature and increas- ing precipitation are main reasons for glacier fluctuation in Manas River basin.