Energy dissipation in non-uniform mangrove forests of arbitrary depth

This study aims to develop a predictive model of wave propagation through non-uniform forest in water of arbitrary depth. The theoretical model solves a full boundary value problem for wave propagation with dissipation for non-uniform mangrove forest and arbitrary water depth. In particular, wave−trunk interaction and wave breaking were found to be the dominant dissipation mechanisms. A modified mild-slope equation including dissipation is applied for wave model over changing water depth within the mangrove forest. The non-linear governing equations for wave−trunk interactions are linearised using the concept of stochastic minimalisation. The numerical results of the model are verified and compared with the experimental wave data in Can Gio Mangrove Biosphere Reserve, Southern Vietnam. The results for wave height, wave spectrum and wave-induced velocities as well as for the coefficients of transmission and reflection suggest that most of the energy is dissipated within the mangrove forest even at relatively small distance. The effect of wave breaking plays a more important role on wave attenuation in sparse forest, however, it is smaller compared to the effect of wave–trunk interactions in the denser forest.