1974—2010年雅鲁藏布江源头杰玛央宗冰川及冰湖变化初步研究

Preliminary Study of the Jiemayangzong Glacier and Lake Variations in the Source Regions of the Yarlung Zangbo River in 1974—2010

青藏高原冰川和冰湖是气候变化敏感的指示器.基于1974年的地形图及其生成的DEM数据、1990年和2000年的TM影像、2005年和2010年的ETM+影像、以及2010年和2009年的GPS实测数据,应用3S技术分析了1974—2010年37a来雅鲁藏布江源头杰玛央宗冰川和冰湖的变化特征.结果表明:冰川面积减小了5.02%(21.78km2减小至20.67km2)、冰川末端退缩了768m(速度为21m.a-1);冰湖面积增加了63.7%(0.70km2增加至1.14km2),冰湖体积扩大约9.8×106 m3.普兰县气象站的观测资料表明,近37a来气温呈快速上升趋势,而降雨量明显减少,气候暖干化是杰玛央宗冰川和冰湖变化的主要原因.若该区气候的暖干趋势进一步加剧,必然导致杰玛央宗冰川退缩进一步加剧,冰湖溃决的可能性将会增大.

Glaciers and lakes on the Tibetan Plateau play an important role in the earth＇s climatic system.Using 3S technology,the variations of Jiemayangzong Glacier and Lake in the last 37 a（1974—2010） are analyzed.Based on topographic map in 1974 and DEM derived from topographic map,TM,ETM＋ and GPS data taken in 1990,2000,2005,2010 and 2009,the changes of the glacier and the terminal lake in different periods were studied.Results show that the glacierized area has decreased 5.02%（from 21.78 km2to 20.67 km2）,the terminal of glacier has retreated 768m（in a rate of 21 m·a-1）;Lake area has increased 63.7%（from 0.70 km2 to 1.14 km2）,volume of the lake has increased about 9.8×106 m3.Moreover,meteorologica1 record at Burang Station indicates that annua1 mean air temperature has had a dramatic increase,while precipitation has obviously decreased in the past 37 years;the warming/drying tendency of climate in this period is the major drive for the variations of Jiemayangzong Glacier and the terminal lake.More rapid glacial retreat and,probably,glacier-lake outburst would be expected if the climate warming and dry condition continue.