The Function of Flood Control by Vegetation in Stream

点击翻译按钮获取中文摘要

People's demands for nature seem to be on the increase in recent years. It is expected that the vegetation in stream have a function of sedimentation as they can be hydraulically regarded as a group of roughness, thus performing to reduce the velocity of flow.However, the function of the flow resistance and sedimentation by vegetation has not been estimated yet.The points of this study are as below.1. Transition of the river bed utilization2. Influence of the vegetation to fluctuation of river bed3. Influence of the vegetation to flood controlIt became clear that shear stress in the stream flow with vegetation can be estimated accurately.As a result when the percentage of area occupied by vegetation is large, the coefficient of roughness increase and the fluctuatin of river bed is reduced.Therefore it is understood that the vegetation has a function to fix river bed.