Remote Sensing Estimation Of Lake Water Storage Over The Tibetan Plateau

The Qinghai-Tibet Plateau lake group plays an important role in the regional climate and water system,but the lack of available data sources has limited the development of related quantitative research for a long period.Quantitatively depicting the water storage of the whole plateau region is a hot issue in the study of climate and environmental changes in the plateau region in recent years.It contributes to enhancing understanding the temporal and spatial variation of lake waters in the plateau region under the condition of global warming and its influence on regional water systems.Therefore it provides a scientific basis for water resources protection and development as well as ecological environment change strategies in the plateau.The study foceses on lakes in the Qinghai-Tibet Plateau(lakes with an area larger than 1km~2)were studied.The lake surface data extracted by multi-spectral remote sensing images and digital elevation model(DEM)were used as data sources.Through multi-model synthesis and spatial feature analysis,lake water storage and spatial distribution patterns in the plateau area was obtained,the main research conclusions mainly include the following aspects:(1)Based on the theory of topographic similarity,the construction method of lake water reserve estimation model is put forward.With this,the area-water reserve model of 168 lakes with an area of more than 50km~2 on the Qinghai-Tibet Plateau is constructed.The accuracy comparison analysis is carried out to select the best model to estimates this part of the lake water storage.(2)Predicting the average depth of 1-50km~2 lakes based on the topographic parameters around the lake,estimating the lake water reserve by the product of the area and the average depth,combined with the 168 area-water reserve model estimation result,the lake area more than 1km~2 of the Qinghai-Tibet Plateau in 2014is estimated.The total water storage are about 915.476 billion m~3,of which 14 are lakes with water storage greater than 10 billion m~3;101 are lakes with water storage of 1~10 billion m~3;and 1095 are lakes with water storage less than 1 billion m~3.(3)The lakes in the Qinghai-Tibet Plateau are mainly distributed in the inland lakes of the inland river basin.Most of the lakes only have runoff inflows,but no runoff flows out,and the glacial snow-capped mountains are mainly distributed in this area.The seasonal melting water makes the lakes in this area numerous.(4)The water storage of the Qinghai-Tibet Plateau with an area of more than1km~2 in 2014,on the one hand,fill in the gaps in the water storage data of the Qinghai-Tibet Plateau;on the other hand,provide the basis for regional water cycle research,global climate change research and water resources analysis.(5)Based on the theory of topographic similarity,168 individual lake area-water storage estimation models only need to obtain the lake area to estimate water storage,which can realize the monitoring of the long-term sequence changes of the main lakes in the Qinghai-Tibet Plateau.