Quantification of wave attenuation in mangroves in Manila Bay using nonlinear Shallow Water Equations

Abstract

In this paper, we investigate the wave attenuation by mangroves using modified 2D Nonlinear Shallow Water Equations. Numerically, we solve the model using a staggered finite volume method that is free from damping error. Further, several benchmark tests are performed to show the robustness of our numerical model. Then, we implement our numerical model to investigate the effects of mangroves in the wave attenuation caused by tsunamis in Manila Bay. The bathymetry profile of Manila Bay used in this study is obtained from the General Bathymetric Chart of the Oceans (GEBCO). Numerical results show that the presence of mangroves can reduce ocean waves near the coast. Simulations on varying density and width of mangrove forest quantify how much the tsunami wave height can be reduced. The results of this work may guide the policymakers of the Philippines in deciding the best strategy in rehabilitating Manila Bay.

Keywords

• Wave attenuation
• 2D nonlinear shallow water equations
• Mangrove
• Tsunami
• Manila Bay