西藏高原典型湖泊面积变化遥感分析

Study on the Change of Lake Area on the Tibetan Plateau Using Remote Sensing Data

西藏高原湖泊水域面积变化能够清晰展示湖泊波动情况,分析近几十年来西藏高原湖泊的面积动态变化特征,对诠释全球变化背景下区域响应特征具有重要意义。利用1972—2020年的Landsat系列和国产高分系列等卫星影像,以及1975年出版的1∶10万电子版地形图,通过人工目视解译方法提取了西藏高原15个湖泊的长时间序列水域面积数据,并分析了近50年来湖泊水域面积变化特征。研究结果表明,1970—2020年15个湖泊水域总面积呈扩张趋势,最低值为1995年的8311 km^(2),最高值为2020年的9191 km^(2),2000—2020年15个湖泊总面积平均每年扩张24.47 km^(2);从单个湖泊消涨趋势来看,2000—2020年15个湖泊中面积呈扩张趋势的湖泊有9个,呈消退趋势的有6个,湖泊消涨趋势存在明显的区域差异,西藏高原北部的大部分湖泊受降水量增加、蒸发量减少等因素影响呈明显的扩张趋势,南部边缘延喜马拉雅山脉北麓的大部分湖泊受降水量减少、蒸发量增加等因素影响呈消退趋势,高原南部区域的冰湖桑旺错受气候变暖导致的冰川融水影响面积正在迅速扩张。

The change in the lake area on the Tibetan Plateau could clearly show the fluctuation of the lake,and the analysis of the dynamic change characteristics of the lake area on the Tibetan Plateau in recent decades is of great significance for interpreting the regional response characteristics under the background of global climate change.Using the 1:100000 electronic topographic map published in 1975 and satellite images obtained from the Landsat series and GF between the years 1972 and 2020,a long-term sequence water area data of 15 typical lakes on the Tibetan Plateau was extracted by artificial visual interpretation,and the characteristics of the lake area change over the past 50 years were analyzed.The result shows that the total water area of the 15 lakes in⁃creased from 1972 to 2020,with the lowest value of 8311 km^(2) in 1995 and the highest value of 9191 km^(2) in 2020.It is also shown that between the years 1972 and 2020,the total water area increased annually by 24.47 km^(2),and among the 15 lakes,the area of 9 lakes increased and the area of 6 lakes decreased.There are obvious regional differences in the expanding and shrinking trend of lakes on this plateau.Due to the increase in precipi⁃tation and decrease in evaporation,as well as other factors,most of the lakes on the northern part of the plateau are found to be expanded significantly,while most of the lakes located in the northern foothills of the Himalayas on the southern edge of the plateau is found to be shrunk because of the influences such as decreasing in precipi⁃tation and increasing in evaporation,etc.However,the glacial lake called Sanwangcuo located on the southern part of the plateau is expanding rapidly due to the increase of glacial meltwater caused by the warming climate.