A Study on Bed Variation during a Flood by Distorted Model Experiments with a Movable Bed

Abstract

The purpose of this study is to investigate bed variation during a flood by a distorted model in which the horizontal scale differs from the vertical scale. Similarity laws for a distorted river model derived from dual dimensionless parameters of the bed form classification diagram for the bars and braids and the Manning-Strickler formula were used. The 9.6km reach (KP6.2-15.8) of the Chubetsu river (a tributary of the Ishikari river) was reproduced in the model. The usefulness of the similarity laws of a distorted model was ascertained, and it was found that the maximum scour depth occurs during a recession of the flood hydrograph.