FLOW STRUCTURE AND BED FORM IN COMPOUND SINUOUS CHANNEL WITH ROUGHENED FLOOD PLAIN

Abstract

Structure of overbank flow and bed form in compound sinuous channel with roughness on the flood plain are discussed based on experimental results. Visualization and measurements of velocity and bed form were conducted. The roughness is set on the bases of the flow structure. Secondary flow is most important in this flow. Effect of roughness on the bed form is significant, but not on the flow pattern on the water surface and velocity distribution. Roughness on the flood plain reduces the surrounding velocity and this reduction causes the local modification of bed. The effect can be observed more clearly in the shallower case.