高水敷に繁茂するヨシの倒伏判定法とそれを用いた非定常平面二次元解析

抄録

To clarify the characteristics of the flood flow in the Rokkaku River affected by large tidal fluctuation of the Ariake Sea, the unsteady numerical model using temporal data of observed water surface profiles is required. And it is necessary for the flood simulation to evaluate the flow resistance of reed lashing in flood plains of the Rokkaku River, which is determined by the behaviors of the reed during a flood. In this paper, the fold-down model of reed is developed based on the previous field experimental results (Fukuoka et al., 2003). We conduct numerical analysis for the 2007 Rokkaku River flood by the unsteady numerical model with the fold-down model of reed using temporal data of observed water surface profiles. It is clarified through the comparison between observed and numerical results that the numerical model can explain unsteady flow characteristics and reed behaviors during the flood.