A flood risk curve development for inundation disaster considering spatio-temporal rainfall distribution

• Main Authors: T. Tanaka, Y. Tachikawa, K. Yorozu
• Format: Article
• Language: English
• Published: Copernicus Publications 2015-06-01
• Series: Proceedings of the International Association of Hydrological Sciences
• Online Access: https://www.proc-iahs.net/370/57/2015/piahs-370-57-2015.pdf

To manage flood disaster with an exceeding designed level, flood risk control based on appropriate risk assessment is essential. To make an integrated economic risk assessment by flood disaster, a flood risk curve, which is a relation between flood inundation damage and its exceedance probability, plays an important role. This research purposes a method to develop a flood risk curve by utilizing a probability distribution function of annual maximum rainfall through rainfall-runoff and inundation simulations so that risk assessment can consider climate and socio-economic changes. Among a variety of uncertainties, the method proposed in this study considered spatio-temporal rainfall distributions that have high uncertainty for damage estimation. The method was applied to the Yura-gawa river basin (1882 km²) in Japan; and the annual economic benefit of an existing dam in the basin was successfully quantified by comparing flood risk curves with/without the dam.