Evaluation of A Coupled Flash Flood and Landslide Modelling System Driven by Radar Forcing

Flooding and flash flooding are the most costly weather-related natural hazards in the United States. Heavy rainfall-triggered landslides are often associated with flash flood events and cause additional loss of life and property. Therefore, it is important to understand the linkage and interaction between flash flood events and landslides. It is also pertinent to build a robust coupled flash flood and landslide disaster early warning system for disaster preparedness and hazard management. In this study, we built a coupled flash flood and landslide disaster early warning system, which is aimed for operational use by the US National Weather Service, by integrating the Coupled Routing and Excess STorage (CREST) model with the physically based SLope-Infiltration-Distributed Equilibrium (SLIDE) landslide prediction model. We tested this prototype warning system by conducting multi-year simulations driven by the Multi-Radar Multi-Sensor (MRMS) rainfall estimates at selected basins across the United States. We then comprehensively evaluated the predictive capabilities of this system against observed and reported flood and landslides events. Our results show that the system is generally capable of making accurate predictions of flash flood and landslide events in terms of their locations and time of occurrence.