COMMUNITIES’ DISASTER PREPAREDNESS PROMOTED EVACUATION: A CASE STUDY OF NAGANO CITY DAMAGED BY THE CHIKUMA RIVER FLOODS CAUSED BY TYPHOON HAGIBIS

Abstract

 This study examined the evacuation behavior of two communities in Nagano City; Naganuma and Toyono, Japan, during the typhoon Hagibis. Despite the width of the inundated area and significant building damage, there were only two victims in the area. We analyzed the relationship between (1) the numerical statement of the aggregated evacuation behavior, (2) social and hazard circumstances, and (3) social background, including the disaster preparedness formulated by the community. The research focused on “the minutia” of factors which have been revealed by previous researches, rather than “the existence or absence” of such factors. The analysis was based on newspaper articles, a post-interview survey conducted by Kansai Television Co. Ltd., the minutes of the flooded area’s past flood control meetings, and community disaster management plans. The results showed that the main factor promoting evacuation action differed in the two communities. This difference lied in each community’s disaster preparedness. Indeed, Naganuma had set a specific and socially agreed upon criterion for evacuation: a specific water level of the Chikuma River. Meanwhile, Toyono had experienced several inland flooding. On the other side, both communities had participated in the flood control meetings and formed organizations for voluntary disaster mitigation action and a common awareness of “what constitutes a dangerous situation” and “which information is important for the evacuation”.