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| DOI：10.13522/j.cnki.ggps.2021596 |
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| Simulating the Impact of Wetland Construction on Flow Velocity in the Lake Fuxian with the Comprehensive Roughness Considered |
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CHENG Haoliang, YANG Jurui
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1. School of Civil Engineering, Southwest Forestry University, Kunming 650224, China;
2. Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650000, China
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| Abstract: |
| 【Objective】The influence of wetland construction considering the comprehensive roughness on flow velocity field of Lake Fuxian was studied to provide the premise for water quality simulation. 【Method】The study was based on numerical simulation by taking the Lake Fuxian as an example. In the ecological water channels, the retarding effect of three types of plants with different heights on water flow was simulated under different flow rates. We considered the comprehensive roughness and calculated the relationship between the comprehensive roughness and plant height, from which we established a two-dimensional hydrodynamic model with the comprehensive roughness of the wetland considered to simulate the flow velocity in the lake. The modelling compared three schemes: existing waterbody, expanded waterbody by removing the breakwater, and whole waterbody after construction of the wetland. The effects of the wetland plants and the expanded waterbody on the flow velocity fields were analysed.【Result】Expanding the waterbody changed the boundary conditions of the local water, increasing the magnitude of flow velocity in the local water while having little impact on water velocity in other areas. In the north shore, the averaged flow velocity was increased by 52.65%, while in the original region, the averaged flow velocity was increased only by 2.10%. The wetland impacts flow field mainly in the wetland area, with the average flow velocity in the south shore decreasing by 68.20%, compared with the expanded waterbody. In the original region, the averaged flow velocity was decreased only by 4.11%.【Conclusion】The constructed lakeside wetland has little impact on original water flow velocity field in the Lake Fuxian even with the comprehensive roughness considered. The method and results presented in this paper can help to design artificial wetlands. |
| Key words: Lake Fuxian; wetland; comprehensive roughness; hydrodynamic model; flow velocity field |
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