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

南开大地震(M8.4-8.5级)发生的概率估计在50年内超过80%，我们对巨型海啸造成的破坏感到担忧。本研究的目的是评估四国岛沿海地区的海啸风险，并探讨将海啸死亡人数降至最低的方法。研究的主要结果如下：(1)以到达时间和海啸高度为评价指标，得出了四国沿海地区的海啸风险。(2)计算死亡人数的方法从海啸时考虑到人们的避难行为为美国制定了，(3)在美国高知市，通过关闭各种闸门，定量地研究了海啸淹没的减少效果。考虑到德岛浅川地震造成的房屋倒塌，提出了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.