In order to mitigate the loss of live and property in a municipal region due to a dyke break or dam break or extremely large flood, it is very important to accurately simulate the movements and distributions of flood in both the temporal and the spatial domains. However, irregular structures and complex inner and outer boundaries within a municipal region can make the simulation complicated. Therefore, a 2D FVM flood simulation model based on arbitrary polygonal mesh system to discretize the 2D shallow water equations is proposed. The numerical simulation model is validated through its application in the Fuji River basin of the central Japan. Results indicate that the simulation model is stable, accurate and easy to capture the properties of flooding waves, and that the model is also suitable for the assessment of flood risks and losses in municipal regions,for the development of hazard maps, flood warning systems and emergency plans.
