Effect of vegetation on spreading and overtopping


Effect of vegetation on spreading and overtopping: numerical experiments with the SWASH model

Given the recent interest in the incorporation of nature-based solutions in coastal engineering works, the use of vegetation could constitute an effective solution in the process of attenuating incident sea waves, with the advantage of presenting environmental benefits. The uncertainty associated with the effect of vegetation on spreading and overtopping on coastal defense works was the motivation for this work. First, the sprawl simulated by the SWASH numerical model was compared with laboratory tests performed with and without vegetation. Second, numerical experiments were carried out with SWASH to analyze the effect of vegetation on overtopping in two beach profiles. Finally, a sensitivity analysis was carried out by placing vegetation, along the closing depth, with a length between 25 m and 200 m. The results obtained indicate that the overtopped flow is reduced by more than 15% for situations in which the length of vegetation is greater than 100 m, regardless of the volume of the emerged beach.

Mendes, D., Fonseca, D., Weber, L., and Haerens, P. (2022). Efeito da vegetação no espraiamento e galgamento: Experiências numéricas com o modelo SWASH. 10as Jornadas Portuguesas de Engenharia Costeira e Portuária, 12 pag.