礫床河川における洪水時の流れおよび浮遊砂・栄養塩輸送に関する数値計算

抄録

A numerical simulation model was presented to describe the flow and the transport of suspended sediment during flood in a gravel river, in which the governing equations were formulated in the generalized curvilinear coordinates to perform the calculation for the actual river geometry. In calculating the sediment transport, 3 different sizes of sediments were considered because the content of nutrient in soil varies with the size of sediment. The changes of the amount of nutrients of the flood plain soil during flood were estimated by using the computational results of the change of the amount of each size of sediment and the chemical composition of the flood plain soil. The results of the computation on the changes of the amount of sediment and nutrients agree reasonably well with those observed in the field.