Energy dissipation characteristics of vegetation belt for the tsunami-like bore

This study investigated the energy dissipation mechanisms of vegetation belts interacting with tsunami-like flows inundating coastal regions. Both experimental and numerical studies were carried out to understand the flow past the vegetation belt. The experiments employed a dam break setup to generate tsunami-like flows interacting with model vegetation, accounting for Froude and Cauchy's similitude. The attenuation process for the inundating bore due to the vegetation belt is through the formation of the hydraulic jump. This transforms the supercritical flow into subcritical flow on the downstream side of the vegetation belt. The effect of vegetation patch length on the hydraulic reflection (Hr) has been reported along with an empirical equation. The strength of the hydraulic jump showed a positive correlation with vegetation belt length. The bore from the hydraulic jump travels upstream, further reducing the strength of the incoming bore. The velocity of the inundating bore is reduced significantly (maximum reduction of approximately 59%) with the presence of vegetation. Furthermore, the microscopic numerical approach provided detailed visualizations of flow characteristics, complementing the experimental observations. The numerical simulation highlighted vortex shedding and its contribution to energy dissipation.