河床変動に関する研究 ―下流端水位低下による河床変動―

Abstract

In this paper the author studied theoretically and experimentally the sediment bedvariation under the boundary condition of the water level drop at the downstream end.The influence of the boundary condition on the bed variation can be expressed by thediffusion equation in the case of quasi uniform flow. It was confirmed by the comparisonbetween each term in the equation of motion for the experimental data that the quasiuniform flow generally took place in the case of bed variation due to the water drop inuniform channels.The bed at the downstream end after the water level drop falls rapidly to the elevationso the depth almost equals to the normal depth. By using the diffusion equation and theabove boundary condition the analytical solution for the bed variation was obtained.The comparison between the theoretical curve and the experimental data shows fairlygood agreement.