Field Investigation into Wave Attenuation in the Mangrove Environment of the South China Sea Coast.

Cao, H.; Chen, Y.; Tian, Y., and Feng, W., 2016. Field investigation into wave attenuation in the mangrove environment of the South China Sea coast. Coastal mangroves form the land-sea interface and face an increasingly aggressive threat from ocean waves as a result of sea-level rise. This study investigates the buffering effect of mangroves on the coast of Leizhou Bay in the South China Sea under two different climates (normal windy weather and storm). By doing this, we aim to establish the exact wave damping rate due to the presence of mangroves and to study the wave and spectral characteristics of wave energy in the vegetated area. Wave gauges are mounted along a cross-shore transect to monitor the wave conditions during particular time periods. From the data analysis, we found that the recorded maximum significant wave height is 22.3 cm at the outermost station and remarkable wave damping was experienced within the mangrove troops of 100 meters. To evaluate the wave dissipation on the mudflat, an empirical expression is proposed on the basis of the field data. In this way, the net vegetation-induced wave dissipation is quantified separately. The spectral analysis of wave energy shows the modalities of frequency-dependent wave energy dissipation under different weather conditions. From the results, we conclude that the wave height was strictly subjected to the concurrent water depth even under the storm condition. The relative water depth (to the wave height) determined wave generation or dissipation on the mudflat. Despite the existence of dissipation by the mudflat, wave energy was majorly attenuated by the mangrove system. The wind growth of wave energy is of great significance when studying the spectral characteristics of wave energy during storm conditions. [ABSTRACT FROM AUTHOR]