Objective  Mangrove forest has become a research focus due to its functions as a newly ecological protector of shorelines. In order to quantify research the root, stem and leaf of mangrove forest, this study aims to experimentally investigate wave height decay along the quantitative generalized vegetation patch with root, stem and leaf.

  Method  The wave height calculated by the formula of Kobayashi was compared with experimental data.

  Result  The results showed that wave damping factors ranged from 0.02 to 0.47. The wave attenuation was lowest as the wave length of incident waves was equal to the length of the vegetation patch. And the boundary effect and wave height increment were observed as wave propagating over the vegetation patch. The relative wave height increment varied from 0 to 13%. When the submergence ratio ranged between 1.0 and 1.2, lower arrangement densities of leaves and roots resulted in higher and lower wave height increment, respectively. Additionally, the relative wave height increment was decreasing with a decreasing arrangement density of roots or leaves when submergence ratio equaled to 0.8.

  Conclusion  The variation of wave height along the vegetation patch appears to depending on arrangement density, submergence ratio and wave length to the length of vegetation patch.