Author(s): Ryuichi Hirakawa; Anji Saikawa; Kojiro Nakamoto; Honoka Aita; Tomokazu Negishi; Yuya Hoshino
Linked Author(s): Ryuichi Hirakawa
Keywords: Flood inundation hazard; Hazard map; Walking in a stream; Evacuation distance; Difficulty of evacuation
Abstract: The purpose of this study is to define difficulty of evacuation in the event of internal flood inundation hazard as an index that includes more than just the depth of flood inundation. Flood inundation analysis was established using historical data for 5-, 10-, and 100-year probability rainfall for short-term rainfall in the target area. The definition of difficulty of evacuation was calculated using three parameters: α, the rate of safe action, which is an index for walking in a stream; β, the rate of shortage of designated emergency evacuation sites, which is an index for evacuation distance; and γ, the rate of shortage of effective walking space, which is the effect of openings on the road. The evaluation of difficulty of evacuation indicated that evacuation was smaller near the evacuation site and larger away from the evacuation site. It was found that its evacuation depended on the depth of flood inundation and the velocity of the flow. In the previous studies, the locations and routes were limited, however, this study showed visualize and evaluated the entire target area. The combined effect of evacuation distance and road area is an advanced one. It is suggested that evaluate the validity of the parameters used to calculate difficulty of evacuation.
Year: 2024