Estimating the difficult-to-evacuate zone of a tsunami in Kamakura city based on the network analysis.

Abstract

In this paper, we aim to reevaluate the difficult-to-evacuate zone, and clarify the current problems of evacuation in Kamakura City. First, evaluation of the tsunami evacuation buildings was done by comparing with the building height and with the maximum reference water level of Tsunami. Next, setting the evacuation target point to where people could escape out of the flooded area, we calculated the evacuation possible area by using 2 indexes, referring to the guideline of evacuation buildings. Moreover, by utilizing reach area analysis of Network Analysis extension by ArcGIS 10.3, we created the area based on the road and defined the evacuation possible area. The other areas were defined as the difficult-to-evacuate zone. And we calculated how many people would have the difficulty to evacuate and verified the landscape district. As a result, we found out that there are areas having the necessity to be assigned evacuation buildings, areas needing a review of landscape district, and areas that need new roads to become the evacuation route while in times of tsunami.