Author(s): Xiaoyan Zhai; Ronghua Liu; Chaoxing Sun; Xiaolei Zhang; Qi Liu

Linked Author(s): Xiaolei Zhang, Ronghua Liu

Keywords: Dynamic risk warning; Flash flood disaster; Multi-factor risk assessment; Soil moisture variability

Abstract: Flash flood disaster induced by heavy rainfall with short duration is regarded as one of the most devastating natural hazards in China. The current flash flood disaster risk warning methods usually neglect the effects of dynamic variations of soil moisture and underlying conditions, resulting in low accuracy of early-warning and frequent occurrences of false alarms. To address this issue, this study combines the real-time dynamic simulation of soil moisture and multi-factor risk assessment, and proposes the flash flood dynamic risk warning model that comprehensively considers soil moisture variability, flash flood hazard, exposure and vulnerability. The accuracy and lead time of the proposed model are assessed taking the historical flash flood disaster events in Guangdong province as an example. Results showed that the flash flood dynamic risk warning model can accurately simulate the hourly variability of soil moisture at catchment scale in the flood season with the determination coefficient greater than 0.90. The warning accuracy of the model was high with a lead time of 24 hours, as the occurrences of three flash flood disaster events were exactly forecasted by the model, which were within the very high and high possibility warning ranges.

DOI: https://doi.org/10.3850/iahr-hic2483430201-457

Year: 2024