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Vertical mass exchange in wetland flows with shear layers
Haoze Fang1, Zhonghua Yang1, Liu Yang1
1State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan, Hubei, 430072, China.
Journal of Environmental Management
|December 5, 2024
Summary
Submerged vegetation in wetlands impacts water purification by affecting solute diffusion. Vegetation density and height slow down solute distribution, while shear layers enhance vertical mixing, crucial for optimizing wetland water quality.
Area of Science:
- Environmental Science
- Hydrology
- Ecology
Background:
- Vertical mass exchange significantly influences solute distribution in wetlands.
- This process affects the efficiency of wetlands in purifying eutrophic water bodies.
Purpose of the Study:
- To investigate vertical mass exchange mechanisms in wetland systems.
- To provide theoretical guidance for optimizing wetland water quality and purification efficiency.
Main Methods:
- Numerical simulation using the random walk method.
- Simulating solute diffusion from a continuous point source with vegetated shear layers and bed absorptions.
Main Results:
- Vegetation density and height inhibit solute diffusion, prolonging equilibrium time.
- A 10% bed absorption probability threshold exists; beyond this, variations have minimal impact.
- Shear layers enhance vertical mass exchange but limit solute absorption in the wake zone.
Conclusions:
- Submerged vegetation has dual effects on vertical mass exchange in wetlands.
- Consideration of these effects is vital for effective wetland ecosystem functioning and water purification.
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