Author(s): Tetsuro Tsujimoto; Ukai; Ryota Tsubaki
Linked Author(s): Ryota Tsubaki
Keywords: Flood risk management; Flood protection; Evacuation; Hazard map; Assessment; Algorithm of human behavior
Abstract: In flood risk management, software to support safe evacuation system should be prepare as well as arrangement of hardware such as constructions of flood levee and flood control dam. For the former, hazard map which shows flood risk to inhabitant as well as community governor for target region plays an important role. However, the assessment of hazard map has not been conducted, and it has not been confirmed that it surely supports the safest evacuation. In order to assess a hazard map, we have to simulate various situations of flood events, and under such virtual situations, various type of behaviors of inhabitants should be investigated when they face to an event. Then, we firstly prepared a model to describe inundation process for various scenario of floods which depend on pattern and magnitude of rainfall, scenarios of flood levee breach that has strong uncertainty. Secondly, we devised a model to describe behavior of inhabitant to evacuate from his origin to destination (refuge). The behavior of action in evacuation depends on the strength of factors to determine his willingness which are his position relative to the refuge, his surrounding condition (inundation depth and velocity) and his recognition of the information from the hazard map. A model to determine his direction and evacuation speed depending on his ability has been proposed. Then, they have been coupled together in order to assess a hazard map. The index of the assessment is the integrated risk along the path of evacuation from origin to destination, and local risk is to be subjected to the local depth and velocity. In this study, the most popular type of hazard map that indicates the overlaid inundation maximum depth has been assessed. Its effect appears for delayed evacuation but the risk is too high, and we have to recommend early start of evacuation.