Development of an estimation method for accidental hypothermia risk due to cold exposure in disasters triggered by earthquakes and tsunamis

Abstract

Freezing deaths due to accidental hypothermia cause human casualties in disasters triggered by earthquakes and tsunamis during severe winters. However, until now, scientific estimates for frozen deaths are not included in earthquake damage estimates. The newly published earthquake damage estimation methodology of Japan's Cabinet Office only considers outdoor evacuees as victims of hypothermia. In this study, we developed a method to estimate the number of frozen deaths due to earthquake disasters, using the International Standards Organization's (ISO11079) coldness index to evaluate the “Duration of Limited Exposure” for disaster victims. Furthermore, we applied the proposed function on the damage assumption for the Hokkaido region in Japan and estimated the number of hypothermia sufferers owing to time elapse. This is the first method to estimate the number of frozen deaths owing to time elapse in earthquake disasters, which will be useful for considering measures to reduce the number of frozen deaths.