Herd Behavior Is Sufficient to Reproduce Human Evacuation Decisions During the Great East Japan Earthquake

Abstract

AbstractWe previously developed an evacuation decision model to represent the herd behaviors of evacuees during a disaster evacuation and employed it to analyze symmetry breaking in evacuation exit choice, a phenomenon in which people tend to gather at one specific exit during an evacuation. This model had yet to be tested against real disaster data owing to a difficulty in acquiring such data. An analysis of video clips captured during the Great East Japan Earthquake revealed unusual evacuation behaviors of people in a meeting room, namely, the evacuation decision between fleeing and drop, cover, and hold-on actions depending on the distance from the exit. Such behaviors have yet to be reported in the literature. We conducted simulations and reproduced these evacuation behaviors using an evacuation decision model and determined that simple herd behaviors among evacuees are sufficient to reproduce these unusual evacuation behaviors. We also conducted logistic-regression, graph-centrality, and sensitivity analyses to examine the nature of these simulation results.KeywordsEvacuation behaviorHerd behaviorDecision-makingVideo analysisResponse threshold model