Author(s): Ryota Tsubaki; Ichiro Fujita; Takeshi Okabe
Keywords: Inundation simulation; Complex topography; Urban are
Abstract: Several methods for detailed inundation flow prediction, using topographical data measured by LiDAR (Light Detection and Ranging) and numerical flow models applied specifically for detailed inundation flow prediction, have been developed over the past few years. These methods were developed to establish sophisticated and efficient procedures. Since a large amount of information on the inundation flow is output by such simulations, the manner in which the simulated information is interpreted is of great importance. The aim of this study, therefore, is to discuss how to best interpret the calculated results. Firstly, a procedure for unstructured grid generation, which the authors developed, is briefly introduced. Secondly, a relationship between the grid resolution and the quality of the generated grids, for which there are several sizes of grid spacing, is verified. Thirdly, the sensitivity of the calculated flow to the grid spacing is investigated. Finally, the distributions of the water surface level and the velocity magnitude are investigated, and a coherent structure of the inundation flow in urban areas is discussed.