Most lakes have undergone significant changes on the Tibetan Plateau in recent decades,affecting water resources on the Tibetan Plateau and its surrounding areas.In this paper,we investigated the variations of 25 lake...Most lakes have undergone significant changes on the Tibetan Plateau in recent decades,affecting water resources on the Tibetan Plateau and its surrounding areas.In this paper,we investigated the variations of 25 lakes in five sub-regions on the Tibetan Plateau from 1972 to 2019 based on SRTM DEM data and Landsat imagery.We used a method to derive lake-levels based on DEM and lake boundaries delineated from Landsat imagery,and then calculated the changes in lake area,level,and volume in 1972 to 2019.We also analyzed the potential impacts of temperature,precipitation,glacial and permafrost melting in lake changes during this period.The results show that the lakes tended to shrink until 2010 in southern and western plateau,after which they began to expand gradually but the overall trend is still shrinking.Limited meltwater from glaciers and permafrost and low precipitation are the main reasons for their shrinkage.The lakes in the central plateau,northwest plateau and northeast plateau tend to expand overall.The reason for the expansion of the lakes is not only precipitation but also the melting of glaciers and permafrost.Overall,the lake changes have gone through 3 phases,namely a slight decrease during 1972-2000,a rapid increase during 2000-2010,and a slowdown in the last decade(2010-2019).Multiple factors such as temperature,precipitation,the state of glaciers and permafrost have contributed to the changes in the lake.展开更多
Lop Sea,located at the east end of the Tarim Basin,Northwest China,dried up permanently,which is the terminal lake of the Tarim River.Lop Sea was considered as the lake basin of Lop Nor since Quaternary.However,the po...Lop Sea,located at the east end of the Tarim Basin,Northwest China,dried up permanently,which is the terminal lake of the Tarim River.Lop Sea was considered as the lake basin of Lop Nor since Quaternary.However,the possibility that Lop Nor was away from the Lop Sea in historical time is crucial to be discussed to interpret the proxy records in sediment profiles.To obtain a general view of the evolution of Lop Nor and Lop Sea in a historical period,several approaches were adopted in this paper.First,the Qianlong Thirteen-Row Atlas,an ancient imperial atlas of the Qing Dynasty,which was completed around 1760,indicated that the Tarim River formed a relatively large lake at its modern upstream region.Second,a Digital Elevation Model(DEM)with a 10-m spatial resolution and a relative precision of 0.42 m was derived from TanDEM-X/Terra SAR-X satellite image pairs using the interferometry method,which was verified using ICESat-GLAS laser footprints and a local DEM acquired by a drone.Finally,based on the spatial analysis of historical documents,expedition reports,sediment profiles and archaeological evidence,it can be deduced that the lacustrine deposition was discontinued in the Lop Sea.Six episodes in the evolutionary history of the drainage system in eastern Tarim Basin were summarized.The proved depositional condition variations could be used for future interpretation of proxy records in sediment.The high-accurate DEM provided a reference for the location of further fieldwork in the Lop Sea.The method proposed in this paper may be efficient for the research of inland lakes or rivers in global arid regions.展开更多
基金This work is supported by the National Key Research and Development Program of China[grant number 2018YFD1100104]the National Key Research and Development Program of China[grant number 2020YFC1521900].
文摘Most lakes have undergone significant changes on the Tibetan Plateau in recent decades,affecting water resources on the Tibetan Plateau and its surrounding areas.In this paper,we investigated the variations of 25 lakes in five sub-regions on the Tibetan Plateau from 1972 to 2019 based on SRTM DEM data and Landsat imagery.We used a method to derive lake-levels based on DEM and lake boundaries delineated from Landsat imagery,and then calculated the changes in lake area,level,and volume in 1972 to 2019.We also analyzed the potential impacts of temperature,precipitation,glacial and permafrost melting in lake changes during this period.The results show that the lakes tended to shrink until 2010 in southern and western plateau,after which they began to expand gradually but the overall trend is still shrinking.Limited meltwater from glaciers and permafrost and low precipitation are the main reasons for their shrinkage.The lakes in the central plateau,northwest plateau and northeast plateau tend to expand overall.The reason for the expansion of the lakes is not only precipitation but also the melting of glaciers and permafrost.Overall,the lake changes have gone through 3 phases,namely a slight decrease during 1972-2000,a rapid increase during 2000-2010,and a slowdown in the last decade(2010-2019).Multiple factors such as temperature,precipitation,the state of glaciers and permafrost have contributed to the changes in the lake.
基金supported by the National Natural Science Foundation of China(42071313,41671353,U1303285,41571363,41431174,61471358,41201346,41301394,41301464)。
文摘Lop Sea,located at the east end of the Tarim Basin,Northwest China,dried up permanently,which is the terminal lake of the Tarim River.Lop Sea was considered as the lake basin of Lop Nor since Quaternary.However,the possibility that Lop Nor was away from the Lop Sea in historical time is crucial to be discussed to interpret the proxy records in sediment profiles.To obtain a general view of the evolution of Lop Nor and Lop Sea in a historical period,several approaches were adopted in this paper.First,the Qianlong Thirteen-Row Atlas,an ancient imperial atlas of the Qing Dynasty,which was completed around 1760,indicated that the Tarim River formed a relatively large lake at its modern upstream region.Second,a Digital Elevation Model(DEM)with a 10-m spatial resolution and a relative precision of 0.42 m was derived from TanDEM-X/Terra SAR-X satellite image pairs using the interferometry method,which was verified using ICESat-GLAS laser footprints and a local DEM acquired by a drone.Finally,based on the spatial analysis of historical documents,expedition reports,sediment profiles and archaeological evidence,it can be deduced that the lacustrine deposition was discontinued in the Lop Sea.Six episodes in the evolutionary history of the drainage system in eastern Tarim Basin were summarized.The proved depositional condition variations could be used for future interpretation of proxy records in sediment.The high-accurate DEM provided a reference for the location of further fieldwork in the Lop Sea.The method proposed in this paper may be efficient for the research of inland lakes or rivers in global arid regions.
