A mathematical model for flood loss estimation
by Dushmanta Dutta, Srikantha Herat and Katumi Musiake
This paper introduces an integrated model for flood loss estimation in a river basin. The model combines a physically based distributed hydrologic model and a distributed flood loss estimation model. The hydrologic model incorporates major processes of the water cycle using physically based governing equations, which are solved to simulate the propagation of water during flooding events. Importantly, the model takes into account man-made flood control structures, such as river embankments and retarding basins, which can significantly impact flooding characteristics.
The integrated model also includes a loss estimation component formulated based on stage-damage relationships between flood inundation parameters and land-use features. By utilizing simulated flood parameters obtained from the hydrologic model, the loss estimation model calculates economic losses specific to different land-use categories during a flood event.
To showcase the model's practical application, a case study is presented involving a medium-sized river basin in Japan that frequently experiences floods. The simulated river discharge and surface inundation obtained from the flood model exhibit good agreement with observed data. Additionally, the loss estimation model accurately captures the urban flood loss when considering the simulated flood parameters, which aligns well with the estimated damage derived from post-flood surveys.
Overall, this integrated model offers a comprehensive approach for flood loss estimation in a river basin. By combining the physically based hydrologic model with the distributed flood loss estimation model, it provides a valuable tool for assessing and understanding the economic impact of floods on different land-use features.
