Author(s): X. F. Yan; W. H. O. Wai; C. W. Li
Linked Author(s): Chi Wai Li, Onyx W.H. Wai
Keywords: No Keywords
Abstract: Riparian vegetation is important in river modification, restoration and rehabilitation. Due to the presence of riparian vegetation, flow is readjusted in accordance with the spatial distribution of the vegetative resistance. In the laboratory, artificial vegetation was set on one side of the open channel to represent one type of riparian vegetation configurations, and this configuration is called partially-obstructed channel with vegetation canopy (POCVC). This study aims to investigate the three-dimensional flow characteristics in the POCVC, which can supplement the present hydraulic knowledge of vegetated flows under different geometric configurations. Experimental results show that the flow is redirected to the upper and neighboring open water regions due to the vegetation canopy, and vegetation density clearly affects the readjustment of mean flow and turbulence in the vertical and transverse dimensions. Particular hydraulic phenomena i. e., velocity deflection and negative vertical Reynolds stress, were observed at the near-bed region in the outer side of the lateral edge in the neighboring open water region, which are believed to be induced by the generation of horizontal coherent vortices.