Study on the Flow Characteristics in Meander Branch Channel with Vegetation
Meander branch channel has formed a complex set of water and sediment movement laws with its unique planar morphology, which has far-reaching impacts on river stability, flood control and navigation. As an important factor to maintain the integrity and health of river ecosystems, vegetation has a gr...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Editorial Department of Journal of Sichuan University (Engineering Science Edition)
2024-01-01
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| Series: | 工程科学与技术 |
| Subjects: | |
| Online Access: | http://jsuese.scu.edu.cn/thesisDetails#10.12454/j.jsuese.202400437 |
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| Summary: | Meander branch channel has formed a complex set of water and sediment movement laws with its unique planar morphology, which has far-reaching impacts on river stability, flood control and navigation. As an important factor to maintain the integrity and health of river ecosystems, vegetation has a great influence on the flow characteristics of rivers, and the flow characteristics of meander branch channel under the influence of vegetation is a special and complex problem. However, there are few studies on the flow characteristics of meander branch channel under the effect of vegetation. In this study, a series of generalized physical experiments on the steady flow of a meander branch channel under various inflow conditions and vegetation densities were conducted, and the flow characteristics of meander branch channel with vegetation were analyzed, which mainly include the water surface elevation, water surface gradient, surface flow velocity distribution, and hydrodynamic axial , and so on. The test results show that the water level of meander branch channel is greatly affected by the flow, and with the increase of flow, the water level shows a stepwise growth, while the water level does not rise significantly with the increase of vegetation density. The presence of branching vegetation and changes in its layout density have a relatively small impact on the longitudinal slope of curved branching rivers, while the transverse slope of each section increases with the increase of branching vegetation density, and the increase in the left branch is more significant. Under the same incoming flow, the flow velocity in the bending branching channel section, branching channel section, and confluence area of curved and bifurcated river sections varies due to the influence of vegetation. Specifically, the average flow velocity in the bending branching channel section increases with the increase of vegetation density, while the average flow velocity in the left channel section changes the same as that in the bending branching channel section. The right channel section shows the opposite trend of change, and the average flow velocity in the confluence area does not show significant changes with the increase of vegetation density. Under the condition of vegetation in the right channel, the hydrodynamic axis of the bifurcation section gradually deviates towards the concave bank side due to the water blocking effect of vegetation, and the higher the vegetation density, the closer the hydrodynamic axis is to the concave bank side; When the upstream flow is relatively small, the layout of vegetation in the tributaries has a significant impact on the hydrodynamic axis of the curved and bifurcated river section. As the flow rate increases, the influence of vegetation on the hydrodynamic axis of the curved and bifurcated river section gradually weakens. These research findings provide theoretical support to a certain extent for relevant channel regulation and river ecological restoration. |
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| ISSN: | 2096-3246 |