考虑水力连通的羌塘内流区洼地单元提取与分类OA北大核心CSTPCD

The Qiangtang endorheic basin,the largest endorheic basin in the Tibetan Plateau,is experiencing a rapid evolution of its lake system structure and water quantity owing to climate change.Considering the impacts of climate change on the boundaries of endorheic units,we propose a novel delineation algorithm introducing the Joint Elevation-Area Threshold(JEAT)to address delineation issues caused by climate change.Firstly,by observing the reorganizations and fluctuations in lake levels in the Qiangtang endorheic zone,we determined that the JEAT was 10 m and 50 km2,respectively.Next,a total of 163 endorheic units with reasonable contribution area and permanent boundaries were identified.The results demonstrated that the algorithm is suitable for extracting endorheic units on a large scale,and the extraction accuracy is superior to that of other existing algorithms and datasets.Subsequently,163 endorheic units were categorized into five main types based on weak watershed type,with the upstream-downstream connected type(Type Ⅱ)and alpine type(Type Ⅳ)being the main ones.Pit type(TypeⅤ)watersheds tended to mostly coexist with other types,exhibiting a more intense response to the connectivity characteristics of large depressions at different periods.