Estimating Fragility Curves for Asset Damage in Business Sector Caused by a Flood Disaster: A Case of the Heavy Rain Event of July 2018 in Japan

Abstract

This paper proposes fragility curves for asset damage based on questionnaire replies from companies that were affected by floods after the heavy rain event of July 2018 in Japan. Fragility curves are a probabilistic method for analyzing structural vulnerability and production facility of companies. Although a fragility curve is a basic model of disaster damage assumption, there has been no case of estimating the asset damage rate at the time of flood damage. In this study, the expected values of the damage rate and the damage cost obtained by the probability distribution of the asset damage rate are smaller than the estimation results in the Manual for Economic Evaluation of Flood Control Investments. These results may reflect the progress of the flood control and the Business Continuity Plan (BCP) of companies; thus, it is important to verify the validity of the evaluation model while continuously updating it.