Evaluating the Performance of Satellite-Based and Reanalysis Precipitation Products in Southwest China

Recently studies usually used remote sensing products and reanalysis datasets to obtain the precipitation. Yet, due to sparse ground observations and complex topography, the accuracy of precipitation products in mountainous regions is one of the great concerns in hydrology. Thus, assessing the accuracy and availability of precipitation products is vital to hydrological research in mountainous regions. In this study, we evaluated the precision of precipitation products including IMERG, ERA5-Land, and AERA5-Asia at multiple temporal and spatial scales using ground observations of meteorological stations from 2001 to 2015 in Southwest China, a typical mountainous region. The key findings are: (1) The IMERG datasets had the best performance on a monthly scale. (2) The IMERG and AERA5-Asia data products had higher precision at seasonal and annual scales. (3) The AERA5-Asia achieved better performance in the high- altitude areas compared to others. In addition, the ERA5- Land has the lowest accuracy. This study can provide important guidelines for the selection of precipitation products for both scientific and management purposes in mountainous areas, especially in Southwest China.