海岸林の生長による津波減衰効果の検討

Abstract

海岸林を構成する樹木は生き物であるため生長して形状を変化させる事になるため，樹木の生長に伴い海岸林による津波減衰効果も変化する事が考えられる．海岸林を津波防災対策に活用させるため，本研究では海岸林の生長および密度管理間伐による津波低減効果の変化を検討した．海岸林樹林構造の変化の検討は，植林後10年ごとの海岸林条件を設定し，植林後50年後までの海岸林の津波減衰効果の変化を数値解析により評価した．

In order to evaluate the tsunami reduction effect of coastal forest due to forest growth, some case of numerical simulation was examined in this paper. The conditions for growth of coastal forest are selected from field survey data. The effect of coastal forest to tsunami reduction is considering with the equivalent roughness coefficient. This equivalent roughness coefficient of coastal forest is varied by inundation depth, tree shape and forest density. From this simulation result, it is shown that tsunami reduction effect of coastal forest is increased by growth of trees. As the return period of tsunami is long in general, this is important result for the maintenance and utilization of coastal forest.