急流河川における蛇行発達メカニズムと堤防防御対策について

抄録

Last September, two nationally managed rivers in Hokkaido experienced dike-washout. In both cases, the bank erosion of the main channel reached the dike while the flood water level was far below the High water level.

In this study, numerical simulations are applied to the Otofuke River, which is one of the two said rivers. The simulations are based on two dimensional flow and sedimentation model, and the meandering shapes of the river channels are approximated by sine waves. In the simulations of actual flood discharge, good results are shown with regard to the meandering shapes of the main channel. And also some basic understandings on the characteristics of meandering are obtained in the simulations of constant discharge. Lastly, some advises are made in terms of risk management and flood control plan.