Accessibility evaluation of evacuation from tsunami on the basis of geographical condition: a case study of coastal area in Tokushima Prefecture: −徳島県沿岸部を事例として－

The purpose of study is to measure accessibility to evacuate from tsunami quantitatively on the basis of geographical conditions such as coastal geometry, location of mid-to-high-rise buildings, road network, population distribution, and so on. We measured road distance from measurement points as “Geo-Evacuatability index” with spacing of approximately 50 meters to higher places or buildings than an estimated height of tsunami in coastal area in Tokushima Prefecture. An accessibility is low in most of low-lying coastal land in peripheral suburban area because higher elevation places and mid-to-high-rise buildings are not much existing. On the other hand, an accessibility is relatively high in the area with ria coast where an estimated height of tsunami is critically high. Since most of the area is relatively high in elevation in low-lying coastal land, it is accessible for residents to higher places than estimated height of tsunami. The result shows that situation is more critical in the low-lying coastal land of peripheral suburbs than that of the ria coastal area.