Author(s): Akihiro Kadotal; Koichi Suzuki
Linked Author(s): Koichi Suzuki
Keywords: Gravel layer; Steep-slope bed channel; Manning coefficient; Darcy-weisbach friction factor
Abstract: In mountain streams, water flows through the gravel layer in normal discharge, because mountain-river has a bed with steep slope and relatively large gravels. And, the water surface goes up over the gravel layer when the flood flow occurs or the flow discharge increases. These two flow characteristics are quite different from each other. The flow through the gravel layer seems to be similar to the flow through the porous media, whereas the flow over the gravel layer follows the law of flow resistance with the roughness of bed material. In this study, flume experiments were carried out in a channel with several slopes with some gravel layers and flow discharge and depth were measured. Also, the flow resistance was examined for the flow through the gravel layer by means of Stephenson (1979) equation. And, Manning coefficient and Darcy-Weisbach friction factor were examined by means of Ugarte and Madrid (1994), Hey (1979), Bathurst (1985) equations for the flow over the gravel layer.
Year: 2001