Decision-Making Under Uncertainty in Tsunami Evacuation: Individual Differences in Information Consultation and Risk Perception (Short Paper)

Abstract

In tsunami evacuation, the two fundamental strategies are horizontal evacuation (moving away from the coastline toward a safer inland location) and vertical evacuation (moving to the upper floors of a building). However, few studies have investigated how individuals make decisions when both strategies are simultaneously available. This study examines how individual differences in lead-time information consultation and in degree of risk aversion affect strategy selection when evacuation begins from inside a high-rise building. A virtual reality (VR) experiment was conducted in an urban environment with 88 participants. Participants evacuated from a seven-story building under three location conditions: Near the Sea, Intermediate, and Near the Mountain. The results revealed that in the absence of lead-time information consultation, participants predominantly opted for vertical evacuation, relying primarily on the perceived safety afforded by the building’s elevation. In contrast, when participants consulted the lead-time information, they tended to select horizontal evacuation. In addition, participants with a higher degree of risk aversion were more likely to select vertical evacuation, but only in the Intermediate condition, where the environmental cues were most ambiguous. These results suggest that individual differences (i.e., information consultation and risk perception) play an important role in evacuees’ decision-making. Overall, the findings indicate that providing personalized information suited to evacuees’ situations can reduce the influence of individual differences and support safer evacuation decisions.