HYDRAULIC EXPERIMENTS ON THE CHARACTERISTICS OF FLOODPLAIN EROSION BEHIND LOW WATER REVETMENT IN STEEP SLOPED RIVERS

Abstract

 In this study, in order to grasp the erosion characteristics of floodplain erosion behind low water revetment in steep sloped rivers, the case of the Otofuke River was verified and hydraulic experi-ments was carried out. It is suggested that the floodplain erosion observed in Otofuke River was caused by the influence of sand bars and the curved watercourse in the low water channel. In the hydraulic experiments, after generating a curved watercourse by sand bar formation in the low wa-ter channel, we observed the floodplain erosion process behind the low water revetment which oc-curs near the flow attacking point. We observed plocess of scour progressing at two points upstream and downstream of the flow attcking point, and process of the erosion area expanding in the transverse direction. The characteristics of the floodplain erosion related to the curved watercourse in the low water channel were shown in this experiments.