COUNTERMEASURES OF EVACUATION AND MITIGATION FOR NEXT NANKAI -EARTHQUAKE TSUNAMI IN SHIKOKU ISLAND

接下来的南开地震（8.4-8.5级）估计在50年内发生的概率超过80%，我们担心巨大的海啸造成的破坏。本研究的目的是评估四国岛沿海地区的海啸风险，并探讨如何减少海啸造成的死亡人数。本研究得到的主要结果如下所示。(1)以海啸到达时间和海啸高度为评价指标，对四国沿海地区进行了海啸风险评价。(2)以高知县土佐市Usa为例，建立了考虑民众避难行动时海啸死亡人数的评估方法。(3)在美国高知市，定量地考察了通过关闭各种闸门来减少海啸淹没的效果。此外，还定量评价了闸门开启和关闭造成的死亡人数变化。提出了考虑到日本德岛浅川地震导致房屋倒塌的海啸淹没时疏散路线的显示方法。

The following Nankai earthquake (M8.4-8.5) is estimated to occur in more than 80 % of probabilities within 50 years and we are anxious about the damage by huge tsunami.The purpose of this study is to evaluate the tsunami risk in the coastal areas of Shikoku island and to examine the way of minimizing the death toll from tsunami.The main results obtained by this research are shown below.(1)The tsunami risk based on an arrival time and a height of the tsunami as evaluation indices was obtained in the coastal area of the Shikoku.(2)The method of evaluating the death toll from the tsunami at the time of taking people's refuge action into consideration was developed for Usa, Tosa city, Kochi.(3)In Usa, Kochi, the reduction effect of the inundation by the tsunami by closing of the various gates was searched for quantitatively. Furthermore, change of the death toll from opening and closing of the gates was evaluated quantitatively.The method of showing the evacuation route at the time of the tsunami inundation in consideration of collapse of the house by the earthquake in Asakawa, Tokushima was proposed.