大野川と乙津川を対象とした樹木群を考慮した準3次元洪水流解析と準2次元解析の改良

抄録

Quasi-three-dimensional numerical simulations of flood flows in the Oono and the Ototsu River were performed to examine the effects of the vegetations as well as curved or meandering or sinuous reach on the behavior of flood flows. A quasi-3D numerical model, which is based on the depth-averaged equation with the effects of the secondary flows and the vegetations on the flows, were used for the simulations. The model was verified through the observation data of the water level and diversion discharge. The effects of the vegetations and the curved or meandering or sinuous reach at the design flood discharge were also examined based on the numerical results, and the relations of water level rise and the distance/discharge were obtained. The quasi- 2D model was shown to be able to reproduce the observation data of water level when the relation described before was used.