Stable isotopes and remote sensing techniques reveal changes in water surplus and loss in alpine inland river basins

Abstract Although the hydrological process of the alpine inland river basin has been extensively studied, the changes of water budget in the alpine inland river basin are still less revealed. Here, a new method combining stable isotopes and remote sensing technology is used to reveal the changes of water surplus and loss in the alpine inland river basin, and accurately identify the water storage areas (water production zone) and water evaporation areas (water consuming zone) during the hydrological changes of basin, providing new insights for the optimal management of water resources of basin. The results showed the monthly water volume showed a surplus state from May to September 2018 to 2019 in the Shaliu River basin. However, there was a serious water loss in the basin from July to September 2020. This is due to the low precipitation, strong evaporation, and high runoff during this period. In response to such significant changes of hydrological processes, the results indicated that there was significant spatial heterogeneity in the variation of water surplus and loss. Based on the hydrological change, we found that the eastern part of basin was water‐producing zone and the southern part of basin was water‐consuming zone. In addition, the upper reaches of the basin were mainly dominated by water storage. This indicated that the upper part of basin was an important water‐conserving area. The results can provide data support for the effective management and planning of water resources in alpine inland river basins.