Wave Attenuation by a Combination of Mangroves and Reefball

Porous breakwaters serve an important role in protecting the coastline by damping the incoming wave. Before implementing these breakwaters, a thorough study is required to assess their effectiveness. We present a mathematical model to examine wave attenuation caused by a combination of reefball and mangroves, serving as both submerged and emergent porous breakwaters, using modified shallow water equations. Our model includes a two-layer representation to account for both types of breakwaters. We then determine the wave transmission coefficient, which represents the degree of wave damping achieved by the combined breakwaters, using a numerical simulation. In addition, we analyzed the relationship between the dimensions of the breakwaters and the wave transmission coefficient. From this study, the result implies that the modified mathematical model has successfully captured the phenomenon and that wave amplitude reduction can be achieved by employing a greater value in the breakwater’s friction coefficient and domain.