Author(s): Tomoharu Hori; Michiharu Shiiba
Linked Author(s): Tomoharu Hori
Keywords: Optimization; Flood; Evacuation; Mitigation; Genetic algorithm; 2D simulation
Abstract: Site and scale planning of in-floodplain mitigation measures are more difficult to solve than that of flood control facilities in river channels since the former requires two-dimensional simulation of flood inundation phenomena in the optimization processes. In order to avoid the impractical computational burden, a two-layered optimization scheme is proposed. The scheme comprises of two levels of search processes: one is approximate solution search process based on simple estimation of inundation levels, and the other is strict optimization stage based on the actual simulation of flood inundation. The nested use of those two levels of searching has considerably reduced the computational burden caused by the inundation simulation and has enabled to get practical solution for the design problem. The optimization scheme is applied to sample design problems, which are formulated as to find the land augment pattern that maximizes the evacuation success rate under the constraint of total land level augmentation volume. The problem contains two large simulation models (2D inundation simulation and evacuation simulation) and so it is almost impossible to find the solution because of huge computational load. In most of the cases, however, reasonable solutions have been obtained with considerably less computational load by the proposed algorithm.
Year: 2007