Author(s): Takayuki Tanaka; Terunori Ohmoto; Shinya Tanaka
Linked Author(s): Takayuki Tanaka
Keywords: Submerged vegetation; Flow resistance; Turbulent flow structure; Momentum transport
Abstract: Hydraulic engineers working on river restoration have been requested to grasp a profound understanding of natural streams as a complex and dynamic system, which involves not only physical elements but biological components. From this viewpoint, the role of riverine vegetation upon river dynamics and flow conditions becomes essential. Vegetation communities are often observed to grow in stripe pattern or patches within many stream channel. In this paper, the influence that interaction of longitudinal vegetation zones gave to the flow resistance in an open-channel was examined experimentally. Laboratory experiments were conducted using a two-component electromagnetic current-meter and a particle-image-velocimetry (PIV) to clarify the momentum transport between main flow and flexible artificial vegetation. Results showed that the flow resistance significantly depended on the lateral distance between longitudinal vegetation zones and the reason could be explained by the difference of momentum transport through the interaction between longitudinal vegetation zones.
Year: 2010