青藏高原湖泊面积、水位与水量变化遥感监测研究进展

青藏高原湖泊数量多、分布广、所占面积大,是亚洲水塔的重要组成部分,其受到人类活动的干扰较少,是理解高原生态环境变化机理的钥匙.青藏高原湖泊是气候变化敏感的指示器,在全球快速变暖背景下其对气候变化的响应如何?本研究基于多源遥感数据监测结果,系统地总结了青藏高原湖泊(大于1 km2)在过去近50 a(1976年-2018年...

Progress in remote sensing monitoring of lake area,water level,and volume changes on the Tibetan Plateau

Lakes are very sensitive to the impacts of climate change and human activities.The lakes over the Tibetan Plateau(TP)are numerous and extensively distributed;they are an important part of the Asian water towers.Understanding the interactions of the Earth system’s circles and the mechanism of environmental changes on the TP requires less disturbance from human activities.What is the response of TP’s lakes to climate change as sensitive indicators in the context of rapid global warming?Based on the lake area mapping with multispectral images,lake water level changes from satellite altimetry data,and lake water volume changes with digital elevation model.This study synthesizes the research progress of area,level,and water volume changes of lakes(larger than 1 km²)on the TP in the past nearly 50 years.The main conclusions are as follows:(1)the total number of lakes on the TP increased from 1080 in the 1970s to 1424 in 2018(+32%),the total lake area expanded from 40,000 km² to 50,000 km²(+25%),the average water level of lakes increased by approximately 4 m,and the lake water storage increased by nearly 170 billion tons.(2)The changes in lake area,water level,and water volume decreased slightly from the 1970s to 1995,and then showed a rapid but nonlinear increase.The lake area,water level,and volume increased in the north-central plateau but decreased in the south.(3)A quantitative lake water balance based on multisource remote sensing data reveals that increased precipitation is the main driver of lake expansion,followed by glacier ablation contribution.Several scientific frontiers facing the challenge are also summarized as follows:(1)quantitative evaluation of the causes of individual lake change.At present,a quantitative study on the causes of lake change indicates the contribution of glacial mass loss to the increase in lake water volume,and precipitation,evaporation,and permafrost underground ice ablation that contribute to the increase in lake water.New driving data sets should be developed and hydrological models from the watershed scale should be further combined to estimate lake water balance.(2)Driving mechanisms of lake changes.The driving mechanisms of lake changes on the TP are currently analyzed mainly to enhance precipitation on the plateau.In the future,climate dynamics theory and hydrological models should be combined to further improve understanding of the driving mechanisms of spatial and temporal differences between the climate system and the cryosphere affecting lake changes on the TP.(3)New satellite remote sensing technology should be combined to understand the past,present,and future lake evolution on the TP.Remote sensing,as an indispensable modern technical means of air-sky-earth,plays a greater role with the implementation of the Second TP Scientific Expedition and Research plan on the TP,and more new satellites are launched one after another to improve understanding of the evolution pattern and change mechanism of lakes on the TP.