Behavior from Tsunami Recorded in the Multimedia Sources at Kesennuma City in the 2011 Tohoku Tsunami and Its Simulation by Using the Evacuation Model with Pedestrian—Car Interaction

Abstract

The evacuation behavior observed in Kesennuma City, Tohoku, Japan during the Great East Japan Earthquake and Tsunami and a corresponding evacuation simulation are presented. We first organized the damage and evacuation behaviors observed in the target area using the results of previous studies and official surveys. In addition, we compiled all available multimedia sources recording evacuation behavior during the 2011 event to identify the precise temporal and spatial details of the evacuation behavior. Then, a tsunami evacuation simulation was developed based on all compiled evacuation data, considering the tendencies regarding the use of main roads for evacuation, residents' shelter preferences, and pedestrian-car interactions. The developed simulation was validated against the compiled evacuation behaviors by inputting the estimated initial conditions of the 2011 event. The traffic scenarios calculated in the simulation closely reproduced the actual traffic flow as observed from the evacuation data. The evacuee populations at several shelters in the simulation also quantitatively reproduced the trend of the real numbers of evacuees reported by Kesennuma City. The results of the simulation exhibited a better capability 1640023-1 F. Makinoshima, F. Imamura f3 Y. Abe to estimate the actual evacuation behavior during the 2011 event than that achieved in previous studies.

Improvement of Tsunami Countermeasures Based on Lessons from The 2011 Great East Japan Earthquake and Tsunami — Situation After Five Years

“…To reveal this type of potential risk during an evacuation, tsunami evacuation simulations, which have recently been studied, are essential tools for the quantitative evaluation of future evacuation events, although accurate simulations require further research on human behavioral characteristics during an evacuation [Mas et al, 2015;Makinoshima et al, 2016]. Every evacuation countermeasure discussed above is important and effective for casualty mitigation during future tsunami events; however, the most important lesson learned from the Great East Japan Earthquake and Tsunami is the strenuous effort required in daily life to prepare for future tsunamis, even when many years have passed since the last event.…”

Possible Factors Promoting Car Evacuation in the 2011 Tohoku Tsunami Revealed by Analysing a Large-Scale Questionnaire Survey in Kesennuma City

“…The 2011 event revealed that car usage, which exceeded the road capacities of local communities, caused severe traffic jams and tsunami casualties [21,22]. Moreover, the same problem was reported in the recent 2016 Fukushima Tsunami [23].…”

“…Figure 1 illustrates the location of the study area and the geographical features of the central urban area for a simulated tsunami [29,30]. Here, the geographical features are those before the 2011 tsunami, and the simulated tsunami was validated in a previous study [22]. As shown in Figure 1a,b, the study area is located in the northeast coastal part of Japan, which experienced a devastating tsunami that reached a height of over 10 m, as illustrated in Figure 1c.…”

“…However, in reality, a chaotic car evacuation process caused severe traffic jams, particularly in the central urban area, and led to a large number of casualties. Detailed information regarding the hazard intensity and the corresponding evacuation behaviours, including spatial analysis, are available in [22]. Investigation of the possible factors that promote inappropriate car evacuation and consideration of appropriate countermeasures are required for future tsunamis.…”

“…Against the worldwide context of rapid urbanization and aging society, the investigation of factors that lead to appropriate/inappropriate evacuation mode choice is expected to provide essential information and implications for future better evacuations, not only in the study area, but also in worldwide tsunami prone areas. In this study, we conducted a statistical analysis using mass questionnaire data regarding evacuation behaviours during the 2011 tsunami in Kesennuma, Miyagi Prefecture, where severe traffic jams occurred during the event [22]. A statistical analysis revealed the factors that promote inappropriate car usage during tsunami evacuation, and the quantitative effect on the decision-making process.…”