Effect of floating vegetation on wind flow and wave in closed water body

When we address a water quality problem in some closed water bodies, it is very important to solve the relationship between the disturbances and flow. Turbulent and convective flows may be induced by mechanical and thermal disturbances, respectively. Disturbances induce the circulation flow of water environmental substance and the water quality depends on this circulation. It is considered that when a mechanical disturbance act on the water surface, the generation of turbulent energy at the water surface and its transportation to the lower layers affects the circulation flow of the water environmental substances. In addition due to the mechanical disturbances act on the water surface, we cannot disregard the effect of the luxuriant growth of floating vegetation and it is conjectured that the impact of disturbances will depend on luxuriant rate of floating vegetation. Therefore, it is important to clarify the effect of luxuriant growth of floating vegetation on the impact of disturbances generated by wind shear. In this study, we particularly focus attention on the mechanical disturbance induced by wind in the closed water body, and we experimentally elucidate the characteristics of the wind flow and wind wave in a closed water body with floating vegetation by using a test tank. The results indicated that the energy of the wind flow was attenuated by the presence of floating vegetation and the attenuation of the energy of the wind wave increased with the coverage of floating vegetation. This attenuation effect was expressed using a resistance coefficient and wave characteristics.