Rainstorm disasters rank among the most impactful natural hazards globally. The application of satellite precipitation products (SPPs) plays a crucial role in enhancing regional disaster prevention and mitigation strategies by improving the accuracy and timeliness of meteorological disaster warning. The Yangtze River Basin, historically prone to severe rainstorm disasters, was selected as the study area. This study evaluates the accuracy of China’s Fengyun series (FY-2 and FY-4; hereafter FY), IMERG-early and PERSIANN-CCS, constructs a basin-scale indicator system for rainstorm disaster risk assessment, and delineates rainstorm risk zones using different FY products. The results indicate that IMERG-early and FY-2G have the highest monitoring capability with a correlation coefficient (CC) of spatial distribution >0.80 and a time series CC >0.70, respectively. FY-4B and FY-4A exhibit similar performance, whereas FY-2H and PERSIANN-CCS show lower performance than the FY-4 series. Thus, a basin-scale rainstorm disaster risk assessment indicator system was developed using the domestic FY-2G product. The risk zoning results show that high- and medium-high-risk areas account for approximately 12.79% and 26.32% of the total basin area, respectively, and are predominantly concentrated in the middle–lower Yangtze region and the Sichuan plain. These high- and medium-high-risk zones exhibit a spatial overlap rate of 82.35% with the rainstorms and their cascading hazards documented in China’s Annual Top 10 Natural Disasters since 2019. Future research should prioritize dynamic exposure assessment and enhance monitoring and early warning applications for specific rainstorm events.
Yang et al. (2026) studied this question.