STUDY OF NUMERICAL SIMULATIONS BASED ON INUNDATION EXPERIMENT CONSIDERING INFILTRATION INTO BUILDING

Abstract

 Flooding experiments were carried out on a building arrangement that simulates an actual urban area and an urban area model that can consider inundation into buildings, and the overall behavior of the flood flow and the water depth at several points were measured. Based on this data, we verified three models that differ in how to handle inundation to buildings in the flood inundation analysis model for urban areas. Building Gap (BG) model in which the building boundary and the mesh boundary are matched and flooded through the slight gap in the building, Building Porosity (BP) model defined by the Ministry of Land, Infrastructure, Transport and Tourism, which evaluates by giving the porosity and drag coefficient in a uniform grid, Building in Mesh (BM) model that assumes a virtual building in a mesh. Of these, the BM model was able to express the inundation situation of flood water without requiring a large computational load. In addition, it was also shown that the application of an unstructured grid that differentiates between streets and city blocks greatly improves the calculation results.