Transport characteristics of suspended sediment in Funing Bay during spring tide in winter

Based on the simultaneous field observations at the eight stations near the area of Funing Bay in December of 2014, the variation in suspended sediment distribution pattern and transport flux during the winter spring tide was analyzed. Combined with the calculation results of the Richardson number, the water mixed potential energy, as well as the change rate of water potential energy caused by tidal power, the effects of vertical mixing of water bodies on the distribution of suspended sediment were also discussed, and the transport mechanism of suspended sediments was studied. The results show that the temperature and salinity increase from inside to outside of the bay, and the suspended sediment share the same trend. The concentration of suspended sediment is obviously asymmetrical during a tide cycle, that is, the concentration of suspended sediment is high during the flood tide inside and at the mouth of the bay except the No.1 station, while the concentration is high during the ebb tide outside the bay except the No. 4 station. From inside to outside of the bay, with the increase in water depth, the vertical mixing of water body gradually weakens, and the vertical difference of suspended sediment concentration gradually increases. The transport of suspended sediment is generally transited to the land inside and at the mouth of the bay, while the transport of suspended sediment is transited to the sea outside the bay. The vertical stratified transport direction is mostly landward with a higher value inside and at the mouth of the bay, while the suspended sediment transport direction is different in the vertical direction outside the bay. The tidal pump transport due to the asymmetry of tidal current and the hysteresis effect of suspended sediment plays a major role in the total suspended sediment transport.