ANALYSIS OF THE START OF A TSUNAMI EVACUATION BASED ON SPATIO-TEMPORAL DATA OF BEHAVIORS AT EVACUATION DRILLS

Abstract

 In order to create communities where people can promptly evacuate from tsunamis, it is essential to understand when, where, or how people begin an evacuation. The aim of this study is to understand the characteristics of the start of a tsunami evacuation using data on evacuation behaviors obtained from evacuation drills. The authors obtained data from evacuation drills held in Ama-Nakanishi district, Minami-Awaji city, Hyogo prefecture in 2016 and 2017. Specifically, data were obtained by shooting an aerial video using an unmanned aerial vehicle (UAV) and another video taken at ground level that moved along with residents during the drill. The authors used this spatio-temporal data to analyze the behaviors of 248 people.
 Data revealed that the process of beginning a tsunami evacuation actually constitutes two parts. In the first, people decide whether to start an evacuation based on either logical judgment concerning infor-mation about the tsunami evacuation or intuitive judgment concerning social reality (sense of urgency) as constructed by not only information about the tsunami evacuation but also all stakeholders in society. In the second, people's decisions to move to safe areas are affected by obstructive factors (e.g., concern for family members or the need to fulfill an assigned role when disaster happens). While slight differences are noted, the overall structure of the process in evacuation drills is closely similar to the process occurring during actual tsunami disasters.