Childcare Center Evacuation to Vertical Shelters in a Nankai Trough Tsunami: Models to Predict and Mitigate Risk

Abstract

Following the Great East Japan Earthquake, vertical evacuation shelters (VES) were constructed to reduce tsunami risk. Childcare centers (CCs) in the inundation area are required to evacuate to the nearest VES in the event of a tsunami. The study aim was to identify CCs and VES predicted to be inundated by a Nankai Trough earthquake-generated tsunami, and to clarify CC inundation risk. We identified 52 (45.6%) CCs in the tsunami inundation area and found that 14 (25.9%) would evacuate toward the tsunami. If the walking speed was 2.24 km/h and a 0.3 m tsunami arrived in 10 min, nine (17.3%) CCs would be late to safe evacuation. If the tsunami arrival time was 20 min, four (7.7%) CCs would have late evacuation. At a walking speed of 1.00 km/h, 38 (73.1%) and 20 (38.5%) CCs would have late evacuation, with tsunami arrival times of 10 min and 20 min, respectively. Evacuation direction is important in avoiding tsunami damage. An evacuation strategy is needed that evacuates people away from the tsunami, and takes into account children’s age, walking speed, and evacuation method. The evaluation of tsunami risk in this study may support the development of tsunami countermeasures in other coastal areas with latent tsunami risks.