EXPERIMENTS ON WAVE REDUCTION EFFECT OF RHIZOPHORA STYLOSA AND ESTMATION OF WAVE FORCE REDUCTION EFFECT

Abstract

 Mangrove forests are a major green infrastructure in tropical and subtropical regions, but their quantitative evaluation is insufficient. In this study, a tree model of Rhizophora stylosa, a type of mangrove, was constructed and hydraulic experiments were conducted under different wave conditions. The drag force coefficient and inertia coefficient were calculated from the hydraulic experiments, and the wave attenuation effect of Rhizophora stylosa was calculated. Numerical calculations using CADMAS-SURF were also conducted to investigate their applicability to numerical calculations.

 The drag coefficient was in good agreement with previous studies, but the inertia coefficient was not, and there remained a problem in handling the flow velocity near the mangrove root. Numerical calculations reproduced the wave height transfer coefficient well and confirmed its validity. Additional calculations showed that a mangrove forest located offshore of the seawall could suppress wave forces acting on the seawall by approximately 50%.