Understanding Hydrodynamic Flow Characteristics in a Model Mangrove Ecosystem in Singapore

Recent importance has been placed on the ecological and socio-economic aspects of mangroves for adjacent coastal populations, in terms of flood defense, food resources, employment and generation of income. Anthropogenic stressors, such as direct clearance, hydrological alterations, climatic change effects or chemical pollution contribute to mangrove ecosystems degradation. While the relative impact is not well understood, the hydrodynamics specific to mangroves (intertidal, land-marine interface) are undoubtedly influencing those effects. In the present study, a computer-based model was built to understand the hydrodynamic flow characteristic in a mangrove ecosystem, the Sungei Buloh Wetland Reserve in Singapore, with the wider intent to better understand the transport of chemical substances in mangroves. Field surveys in the mangrove and the preliminary development of a two-dimensional hydrodynamic (2DH) model have been carried out. Higher bottom roughness was considered in the vegetated part of the model domain to account for the effect of mangrove roots. Spatial and temporal distributions, as well as minor mean differences between simulated and observed results, suggest that the developed model capture satisfactorily the tidal dynamics within the river, the wetland area covered with mangroves and in the strait. These results indicate that the hydrodynamics are properly understood within the Sungei Buloh mangrove ecosystem and can be used for modeling the fate of chemicals.