Moisture Sources of 28 River Basins of Northwest Inland Region of China During Summer Extreme Precipitation Events

Water resources shortage is the key issue that impedes the economic, social and ecological development of northwest inland region of China. A deep insight into the atmospheric moisture transport and moisture sources of the region is helpful for understanding the mechanisms behind the formation, transfer and conversion of water resource. By using the Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE) daily gridded precipitation, the NCEP/NCAR reanalysis data and the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), the major moisture transport paths and moisture sources of 28 river basins of northwest inland region of China during the summer extreme precipitation events are quantified based on the Lagrangian trajectory frequency analysis and a widely used Lagrangian moisture source attribution tool. The moisture transport path analysis shows that the moisture transport paths from the Eurasian continent are the major transport branches for all basins and paths from the Indian Ocean, the Bay of Bengal and central and south China serves as major transport branches for the southeastern part of northwest inland region. The 28 river basins are grouped into 6 subregions based on the moisture path frequency spatial distribution. The moisture source analysis shows that the terrestrial moisture sources from the Eurasian hinterland and central and south China serves as major moisture sources for the region, and oceanic moisture sources contribute little to the target region precipitation, as oceanic moisture is mostly lost before reaching the target region.