Author(s)

M. Thomas & T. Tsujimoto

Abstract

Today, flood risk in Japan occurs mainly in high density populated areas, as a consequence of the rapid urban development of the deltaic plains of Japan during the second half of the 20th century. At the end of the 20th century risk management began to shift from mainly structural management to a more \“integrated” management. The evacuation process is one of the factors revealing this shift. In Nagoya the evacuation process enhancement started with the Tokai flood disaster (September 2000) and continues to this day. The most recent flood events (urban flood of 2008 and typhoon No. 14 of 2011) highlight, however, how the crisis management can still be vulnerable regarding evacuation. Our research intends to assess the vulnerability factors of the crisis management system, and especially of the evacuation process through interviews and a questionnaire analysis method, in order to propose an integrated way of dealing with evacuation in the case of a flood, imputing on GIS geographical as well as social characteristics and evacuation patterns. Our research shows that the evacuation process is effective despite low evacuation rate during past flood event. In that regard improving the evacuation process cannot be separated from the improvement of informational tools, but it can be seen that the possession of hazard maps have few impact on evacuation decision. The efficiency of the evacuation process in the case of a small to moderate flood event could therefore be enhanced as the large-scale evacuation broadcast tends to target a population in which more than half of the people do not need to evacuate. In the case of a small flood event those repeated evacuation demands can increase a relatively false sense of security and a loss of interest to flooding in general.

Keywords

vulnerability, adaptive capacity, floods, evacuation, GIS, Japan.