Using Multisource Satellite Data to Investigate Lake Area, Water Level, and Water Storage Changes of Terminal Lakes in Ungauged Regions

Lake area, water level, and storage changes of terminal lakes are vital for regional resource management understanding local hydrological processes. Nevertheless, due to the complex geographical conditions, it is difficult investigate analyze this change in ungauged regions. This study focuses on ungauged, semi-arid Gahai Lake, a typical small lake Qaidam Basin. In addition scant observed data, satellite altimetry scarce excessively large fraction outlier points. Here, we proposed an effective simple algorithm extracting available elevation points from CryoSat-2, ICESat-2 Sentinel-3. Combining with area data Landsat, Gaofen (GF), Ziyuan (ZY) satellites, built optimal hypsographic curve (lake versus level) based existing short-term data. Cross-validation was used validate whether accurately could predict level other periods. addition, multisource high-resolution images including Landsat digital maps extract 1975 2020, applied estimate corresponding period. Additionally, adopted pyramidal frustum model (PFM) integral (IM) long-term changes, analyzed differences between these two models. We found that there has been obvious since beginning 21st century, which reflects impact climate human activities hydrologic processes basin. Importantly, agricultural have caused rapid increase over past decade. collected as much possible; thus, estimated variations combining multiple models, can provide method monitor basins.