Author(s): Yuanheng Zhang; Xu-Feng Yan; Xie-Kang Wang; Huan-Feng Duan
Linked Author(s): HF Duan
Keywords: No keywords
Abstract: Vegetation canopy patches are widely existent in natural rivers and streams, whose presence can modify to different extents the flow structure and deposition pattern, ultimately affecting the channel morphological evolution. Previous studies have noted that the formation of canopy-scale von Karman vortex is highly related to the velocity difference between the wake region behind the canopy and the free stream region. When flow enters the canopy, it will be diverted into the outer regions due to the vegetation-induced resistance, leading to velocity reduction. Moreover, it is also demonstrated that this resistance is highly dependent on vegetation density and dimensions. However, it is not very clear from these previous studies on the threshold value of different vegetation canopy characteristics (such as shapes, aspect ratios and vegetation densities) for the initiation and evolution of von Karman vortex behind the canopy.
Year: 2022