Author(s): Youzhi Hao; Dongdong Jia; Xingnong Zhang
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Keywords: No keywords
Abstract: As an important biological factor in the river system, vegetation is widely distributed in the riparian waterfront area. The contact between vegetation and water flow will disturb the water flow and change the river flow characteristics, and even the scouring of the slope foot, the stability of the river bank and the evolution trend of the river morphology will also be affected. In order to clarify the effect of riparian emergent rigid vegetation covering along the water flow direction on the water flow characteristics of the compound river, the vegetation was regarded as the wall boundary, and the Reynolds stress model was used to close the turbulent flow control equation to construct a three-dimensional hydrodynamic mathematical model. The model was applied to simulate the flow characteristics of the compound channel with and without vegetation on the bank slope. The results show that vegetation aggravates the lateral momentum exchange between the main channel and the floodplain. The riparian vegetation increases the number, intensity and extent of the secondary flow eddies compared to no vegetation. At the same time, vegetation significantly reduces cross-sectional flow velocity, bed shear stress, flow distribution, Reynolds stress and turbulent kinetic energy in the beach-trough junction area. But the turbulent exchange was obviously increased in the area around the vegetation.
Year: 2022