The spatiotemporal pattern characteristics of extreme precipitation-induced flood disaster risk in Chinese counties

Under the combined effects of climate change and human activities, China is experiencing extreme precipitation events that are increasing, posing a significant threat to socio-economic development. Currently, there is little research on the spatial differences in the extreme precipitation-induced flood disaster risk (EPFDR) in Chinese counties. Therefore, we developed an analytical framework and an EPFDR indicator evaluation system, revealing the dominant factors and transition processes of disaster risk in different regions of China in the counties. The results show that: (1) Between 2000 and 2020, 66.34% of counties in China experienced an increasing trend in EPFDR, with disaster risk following a pattern of increasing in the southeast and decreasing in the northwest; (2) The spatial clustering types of EPFDR of China in the counties are mainly high-risk clusters (H-H) and low-risk clusters (L-L), forming multiple high-value centers in the Huang Huai Hai Plain, Middle Yangtze River, Lower Yangtze River, and Southern Coastal regions; (3) The counties in the Huang Huai Hai Plain and Lower Yangtze River regions have EPFDR and subsystem average values higher than the national average; (4) In the Huang Huai Hai Plain region, disaster-prone environment sensitivity dominates; in the Lower Yangtze River, Middle Yangtze River, Southern Coastal, and eastern Southwest regions, hazard factor risk is the primary factor; in the Northwest region, the interaction between disaster-prone environment sensitivity and exposure unit vulnerability dominates.These findings are conducive to the understanding of EPFDR under the dual effects of climate change and urbanization and the formulation of adaptive strategies.