No abstract

A damage function that indicates the relationship between flood depth and damage is important to quantify natural catastrophe risks. Previous studies estimated the flood damage ratio using theoretical methodologies and in-person interviews. Although it is difficult to obtain actual damage information, it can be reflected in damage functions using insurance loss data. This work aims to develop damage functions for buildings and their contents using insurance loss data from the 2015 Kanto-Tohoku heavy rainfall incident. First, we collected information on the insurance losses and calculated damage ratio by property. Second, we analyzed inundation from the Kinugawa river using the flood model. Finally, we combined the simulation results with the damage ratio and developed flood damage functions as useful risk-assessment tools.