Sediment Transport and Short-term Sedimentation Processes in the Tidal Flats of the Ariake Sea, West Coast of Kyushu, Japan

Predicting suspended sediment transport in coastal waters is an important task in coastal engineering and related areas, not only to dredging but also to living systems due to the ability of fine particles to adsorb nutrients and contaminants. In this study, the hydrodynamic characteristics of water flow and suspended sediment transport in the tidal flat of the Ariake Sea were studied using a numerical hydrodynamic mud transport model. The model was calibrated with observed water level, current, salinity and suspended solid concentration data in 2004. The model could reproduce the dynamic processes of water flow, current velocity, salinity and suspended solid concentration over the simulation period. It was found that the tidal currents play an important role in the sediment resuspension in the tidal flat area and the majority of the released sediment during both the ebb and flood tides will deposit on the tidal flats. Most of the sediment delivered by inland rivers surrounding the tidal flat is deposited in the western part of the sea.