Attenuation of Hydro-Sediment Dynamics Progradation Over Mangrove Wetland

Abstract

Mangrove wetlands are one of the vital ecological resources that effectively trap sediment and attenuate the dynamic of waves and currents, thus protecting coastal areas from the onslaught of typhoons. Despite their importance, there is a dearth of knowledge regarding how mangrove dynamics influence hydro-sediment dynamics and dissipation effects. Here, the wave, current, and sediment data, along with sediment particle size and mangrove vegetation parameters are used to analyze the variation of hydro-sediment dynamics along the mangrove wetland. Our findings reveal that bottom flow velocities exhibit a continuous clockwise dispersion in a disordered pattern from the bare flats into the mangrove interior, influenced by the increasing density of mangroves. Furthermore, the hydro-sediment elements exhibit pronounced tidal asymmetry, with the values of bottom velocity, suspended sediment concentration, and suspended sediment flux (SSF) shifting from being higher during flood tides to being higher during ebb tides due to tidal motion. Meanwhile, we found that the SSF at the mangrove edge may be the main source of the elevation changes at the mangrove interior. The vertical structure of Aegiceras corniculatum significantly affects sediment transport, with a notable decrease in SSF in areas with dense canopies. This study contributes to the body of knowledge on mangrove dynamics and their impact on sediment transport and hydro-sediment damping, providing valuable insights for mangrove conservation and restoration efforts.