The Impact of Information Seeking on Tsunami Evacuation Behavior
Genki Nagano (AY 2018)
Natural disasters are an unavoidable threat in Japan, and the Great East Japan Earthquake of 2011 claimed more than 20,000 lives, both dead and missing, with more than 90% of the victims dying from drowning caused by the tsunami. In addition, the occurrence of an earthquake of the same magnitude as the Great East Japan Earthquake is predicted with a high probability, making it an important issue to develop earthquake and tsunami countermeasures. Most of the previous studies on earthquakes and tsunamis have attempted to elucidate their mechanisms or focused on damage surveys, while those on tsunami evacuation behavior have only clarified the factors affecting evacuation. Therefore, few studies have clarified what kind of evacuation behavior these factors led to. In addition, although diversity of information is one of the characteristics of a disaster, there are also few studies that have clarified how the different types of information obtained after the earthquake affected evacuation behavior. Therefore, this study aimed to clarify the process of tsunami evacuation behavior from the occurrence of an earthquake to the end of evacuation by analyzing from the perspective of ordinary disaster victims, focusing on their information-seeking behavior. In addition, the study aimed to categorize tsunami evacuation behavior patterns, and to discuss and propose future tsunami evacuation support measures based on the categorized processes and the knowledge gained in the process.
To achieve the above objectives, 24 interviews on "Evacuation Behavior at the Time of the Earthquake" conducted with disaster victims on the website "NHK Great East Japan Earthquake Archives" were selected for analysis. A modified grounded theory approach, a type of qualitative analysis that attempts to generate theories that can predict and explain human behavior in processual events, was adopted as the analysis method.
As a result of the analysis, 37 concepts and 8 conceptual categories were generated. As a result of examining the relationships among the concepts, it was found that the concepts, which represent a series of tsunami evacuation behaviors from the occurrence of an earthquake and the feeling of shaking to the completion of tsunami evacuation actions, can be classified into four groups: "decision to evacuate," "highly planned evacuation," "poorly planned evacuation," and "after the completion of evacuation actions. The main tsunami evacuation action processes included the pattern of anticipating the arrival of a tsunami based on the feeling of the tremor, planning an evacuation plan, and then re-planning the plan according to the situation, and the pattern of being overconfident based on past experience and starting evacuation actions only after hearing the calls of others, but then making a hasty decision to follow others when a tsunami approached. However, when the tsunami approached, they made a hasty decision to follow others. Based on these findings, it is believed that measures to support tsunami evacuation should be taken to accelerate the timing of the start of evacuation, rather than measures to build a foundation to make disaster victims aware of the image of the tsunami and the danger it poses, or measures to support their actions after the start of evacuation. In light of this, measures such as "changing the way information about disasters is presented" can be identified.
These are the main results of this study. Future work includes analysis using denser data and analysis of emotions.
(Translated by DeepL)