|Interaction of submerged vegetation, hydrodynamics and turbidity: Analysis of field and laboratory studies|
|Houwing, E.J.; Tánczos, I.C.; Kroon, A.; de Vries, M.B. (2002). Interaction of submerged vegetation, hydrodynamics and turbidity: Analysis of field and laboratory studies, in: Winterwerp, J.C. et al. (Ed.) (2002). Fine sediment dynamics in the marine environment. Proceedings in Marine Science, 5: pp. 441-453|
|In: Winterwerp, J.C.; Kranenburg, C. (Ed.) (2002). Fine sediment dynamics in the marine environment. Proceedings in Marine Science, 5. Elsevier: Amsterdam. ISBN 0-444-51136-9. XV, 713 pp., more|
|In: Proceedings in Marine Science. Elsevier: Amsterdam. ISSN 1568-2692, more|
submerged vegetation; plant-flow interaction; cohesive sediment; dissipation; turbulence
Both field studies and laboratory experiments were carried out in order to identify relevant processes that cause the phenomenon of a clear water phase above submerged vegetation fields, as commonly observed in lakes in The Netherlands.
Results from the field study revealed that an increase in the turbidity level of lake waters is due to local wind induced wave activity. Advective transport of suspended sediment is shown not to contribute to changes in the turbidity level. Resuspension of bed material by waves is likely confined to a so-called 'fluffy layer'. Results from the laboratory study showed that submerged vegetation decreased the eddy diffusivity by affecting both the turbulent kinetic energy and the sizes of the turbulent structures. However, this did not result in an increase in sedimentation within the vegetation field. Waves were effectively damped by the vegetation. This effect is a function of plant morphology (stiffness and plant length).
Results from the laboratory experiments therefore corroborate the findings from the field study: the phenomenon of a clear water phase above submerged vegetation canopy is most likely due to the dampening effect of waves by the vegetation, which inhibits local resuspension of the sediment bed.