1976-2019年西藏杰玛央宗冰川变化遥感监测

Study on the Variation of Chema Yongdrung Glacier in Tibet Using Remote Sensing during 1976—2019

青藏高原是中低纬度冰川分布最广的地区之一,其冰川不仅是各大江大河的源头,也是气候变化敏感的指示器。近年来,由冰川变化带来的次生灾害如冰崩、冰湖溃决等现象越来越多,因此,研究冰川变化的规律和特点对反映区域气候变化及防灾减灾具有重要意义。文章利用1976-2019年Landsat卫星遥感数据,2000年SRTM数字高程模型数据,2000-2016年高亚洲冰川厚度变化数据集以及冰川周边西藏阿里地区普兰县气象站气候要素数据,通过人工目视解译、水文分析等方法对位于喜马拉雅山脉的西藏雅鲁藏布江正源杰玛央宗冰川开展了长时间序列综合分析。结果显示,近43年杰玛央宗冰川面积减少1.61 km^2,面积变化率为7.01%,冰川末端高程抬升,冰川长度缩减,冰川表现负物质平衡,冰川末端冰湖范围明显扩大,冰湖面积增加0.55 km^2,库容量增加25.3×10^6 m^3。结合普兰县气象站气候数据发现冰川与最高、最低和年平均气温的关系最显著,气温升高是冰川变化的主要原因,该地区冰川基本可以反映高原亚寒带干旱气候区的气候变化。

The Qinghai-Tibet Plateau(TP)is one of the regions with the most widely distributed glaciers in middle and low latitudes.Glaciers on the TP are not only the source of major rivers in Asia,but also a sensitive indicator of regional climate change.In recent years,there are more and more secondary disasters due to glacier melting were found,such as ice collapse and glacial lake outburst.Therefore,it is of great important to study the rules and characteristics of glacier change to reflect regional climate change and to prevent and reduce disasters.Using data including Landsat satellite remote sensing data during 1976-2019,SRTM digital elevation model data of 2000,Asian glacier ice thickness change data during 2000-2016,and meteorological data of Pulang station of Ngari region,and applying artificial visual interpretation and hydrological analysis methods,we have carried out long-term and comprehensive analysis of Chema Yongdrung glacier,which is located in the Himalayas mountain range and is the source of Brahmaputra river.The results show that in the past 43 years,the surface area of Chema Yongdrung glacier has decreased 1.61 km^2 with the area change rate of 7.01%.In the mean time,the elevation of the glacier end has risen and the length of the glacier has decreased.Moreover,the area of lake located at the end of glacier has expanded significantly,with the increased area and increased storage capacity of0.55 km^2 and 25.3×10^6 m^3,respectively.And the glacier is in negative matter balance.Combined with the meteorological data obtained from meteorology station in Pulang County,it is found that the relationship between glaciers and maximum,minimum and annual average temperature is the most significant.And hence increase of temperature is the main reason for the change of the glacier.