干旱区暴雨山洪淹没数值模拟与验证

In the context of climate change and human activities, flood disasters in arid mountainous areas become increasingly frequent, and the safety of people's lives and property has been seriously threatened. Rapid and accurate flash flood inundation modeling is an important and basic work to reduce casualties and disaster losses, and it is also a bottleneck problem that needs to be solved urgently in flash flood forecasting and warning. This paper aims to construct a numerical modeling method for flash flood in drylands. Based on a 2D high-resolution flood numerical model (FloodMap- HydroInundation2D), we hindcast the dynamic process of flash flooding and reveal the spatio- temporal characteristics of flash flood inundation for the "8.18" flash flood disaster that occurred in Datong county, Qinghai province. The results show that the model output agrees well with the observed inundation after the event, in terms of both spatial extent and temporal process. The extensive flooding mainly occurred between 00: 00 and 1:00 on August 18, 2022. Qingshan, Hejiazhuang and Longwo villages are most heavily affected. We further conduct model sensitivity analysis and find that the model is highly sensitive to both roughness and hydraulic conductivity in drylands, and the effect of hydraulic conductivity is found to be more pronounced. This study confirms the good performance of the model for the simulation of flash flooding in arid areas, unlocking the potential for flash flood assessment and management in arid areas.