Abstract
A new optimal design framework including mitigation countermeasues taken in floodplains is proposed based on distributed risk assessment in urbanized areas. In order to take both of human damage and economic one into account and to incorporate non-facility-based countermeaseures, ‘damage level’ is defined. The damage level is computed based on the combination of external force level, which is derived from several aspects of inundation flow dynamics, and flood-proof level, which is defined by protection and mitigation ability at each point in a floodplain. With the clear reference to project time scale and feasibility, the planning problem is formulated as a permutation optimizing problem under the budgetary constraints. A solution search algorithm based on genetic algorithm is proposed to find optimal solutions of the large and complicated system design problem including non-linear numerical simulation.
