Importância da flexibilidade da vegetação na dissipação de energia da onda

Abstract

This work is based in laboratory tests, from the observation of artificial lakes' margins change due to hydrodynamic agents, caused by water waves. It is known that vegetated margins are less susceptible to erosion effects then unprotected ones. Regarding to the energy dissipation, there are many uncertain parameters, mainly related to its quantification, as the drag coefficient of oscillatory flow on flexible structures, for example. The capability of the drag coefficient trying to simulate the dynamic of the vegetation is discussed. It is proposed to realize some experiments in order to establish limits to include the flexibility in a model using a numerical tool. The goal of the numerical model was to comprise the energetic aspect (water wave energy loss) and also the dynamic aspect (movement of vegetation). The experimental results, when simulating the vegetation (Ilha Solteira's reservoir margins) by nylon ropes, were obtained and compared with the numerical ones, showing reasonable approach of the limit that should be used to include the flexibility in the model.