Author(s): Khanh Linh Phan; Son Hong Truong; M. J. F. Stive

Linked Author(s): Linh Phan Khanh

Keywords: Vegetation; Experiment; Numerical model; Long waves

Abstract: The role of vegetation in general and mangroves in particular for the riverine, estuarine and coastal regions has been recognized in recent decades. For example, the complex systems of roots, stems, and canopies enable mangroves to absorb external forces such as due to tsunamis, waves, and currents. Though many studies have been conducted, they mainly focus on the attenuation of regular waves. The effects of wave non-linearity on wave height attenuation by rigid vegetation is not fully understood. A unique experiment mimicking the processes of wave attenuation was conducted at the TU Delft lab. Different wave characteristics, including regular, irregular, broken, and non-broken waves, were considered. It is suggested that the wave characteristics have significant influences on the wave attenuation processes inside vegetation. In this context, the wave height attenuation rate was described as a function of the Ursell number and the number of wavelengths. A numerical model mimicking the experiment was constructed in SWASH. The model was validated using the experimental data. The results suggest that the numerical model can well reproduce the transformation processes of the wave attenuation observed and measured in the experiment. Finally, the experimental data set was extended through the numerical model.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022222

Year: 2022