REFINEMENT OF DOUBLE GRID MODEL FOR EFFICIENT SIMULATION OF FLOOD INUNDATION IN AN URBAN AREA

Abstract

 The double grid model employs two scaled grid systems: a fine grid for storing topographic and roughness data and a coarse grid for solving governing equations in order to simulate large scale flow phenomena efficiently. To apply the double grid model to flood in an urban area, I refined the double grid model by considering the drag force due to the buildings inside the coarse grid cells and strict mass conservation at wet and dry cell transitions. The modified model was applied to the previous flood experiment in Sapporo city area. The computational results showed that the present model can simulate reasonably a flood inundation at an urban area.