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Aquatic vegetation affects sediment suspension and nutrient release by changing the flow structure.Experiments on the influence of submerged vegetation on flow structure,sediment suspension,and NH4-N release were carried in a flume with natural submerged vegetation.Turbulence characteristics in the vegetation section were measured using a three-dimensional acoustic Doppler velocimeter.The effects of submerged vegetation on bed shear stress(),sediment suspension,and NH4-N release were analyzed.Results show that with vegetation,bed shear stress is reduced by about 20%-80%,which,in turn,reduces sediment suspension.The impact of submerged vegetation on sediment suspension and NH4-N release should be considered along with flow intensity.When the flow Reynolds number is relatively small,the submerged vegetation is quite capable of inhibiting sediment suspension and reducing NH4-N release,but when the Reynolds number reaches a certain value,the presence of aquatic plants exacerbates sediment suspension and promotes NH4-N release.Results also reveal that a highly significant positive correlation exists between NH4-N concentration and water turbidity in both vegetated and non-vegetated channels.
Aquatic vegetation affects by sediment suspension and nutrient release by changing the flow structure. Experiments on the influence of submerged vegetation on flow structures, sediment suspension, and NH4-N release were carried in a flume with natural submerged vegetation. Turbulence characteristics in the vegetation section were measured using a three-dimensional acoustic Doppler velocimeter. The effects of submerged vegetation on bed shear stress (), sediment suspension, and NH4-N release were analyzed. Results show that with vegetation, bed shear stress is reduced by about 20% -80 %, which, in turn, reduces sediment suspension. impact of submerged vegetation on sediment suspension and NH4-N release should be considered along with flow intensity. WHEN the flow Reynolds number is relatively small, the submerged vegetation is quite capable of inhibiting sediment deposition suspension and reducing NH4-N release, but when the Reynolds number reaches a certain value, the presence of aquatic plants exacerbates sediment suspension and promotes NH4-N release. Results also reveal that a highly significant positive correlation exists between NH4-N concentration and water turbidity in both vegetated and non-vegetated channels.