Comprehensive evaluation of satellite-derived precipitation products considering spatial distribution difference of daily precipitation over eastern China

Abstract

Study region: Eight main basins at eastern China. Study focus: This study proposes a comprehensive framework using Shannon’s entropy-weighting method for assessing satellite precipitation data from spatial and temporal perspectives. First, three new spatial evaluation metrics, the false monitoring score (FMS), spatial coverage approximation (SCA), and precipitation spatial difference index (PSDI), were introduced based on spatial distribution differences of daily precipitation. Then, the error and performance of the five satellite precipitation datasets over eastern China were analyzed. New hydrological insights for the region: The spatial metrics, SCA, PSDI, and fraction skill score (FSS), provide an effective quantitative evaluation of the daily spatial distribution of precipitation. CMADS and MSWEP appear to be superior at reproducing the spatial distribution of precipitation. Except for CHIRPS, all other four datasets have a tendency to underestimate precipitation measurements in the study area. According to the evaluation, the latest version of MSWEP may be a suitable alternative for use in water and climate research due to its relatively high accuracy in eastern China. The spatial error analysis method utilized in this study can be transferred to evaluating other gridded precipitation products. Meanwhile, the spatial error indices are also acceptable as optimization targets for future satellite precipitation data production.

Keywords

• Comprehensive evaluation
• Spatial errors
• Satellite precipitation products
• Eastern China