Abstract: In the aim of investigating the sediment characteristics and topography evolution in Xinghua Bay, the distribution characteristics of sediment and the effects of suspended sediment transport on topography evolution were analyzed based on measured data of hydrology and sediment in Xinghua bay in July, 2013 and measured data of deep channels of Xinghua bay in the past years. Results show that sediment concentration is small in the study area,with the average sediment concentration only 0.062 kg/m³, and the average sediment concentration of spring tide is larger than that of neap tide. Moreover, sediment concentration changes obviously with tide fluctuation, and maximum concentration most appears when the velocity of rising tide reaches the maximum, while minimum concentration most appears when the velocity of falling tide reaches the maximum, indicating that sediment in the sea area is slightly disturbed. In addition, sediment discharge rates of rising tide are bigger than those of falling tide, but the absolute values of sediment discharge rate of two tides are very small. Finally, sediment in the area flows in and out with the tides, mainly transporting from the southeast to the northwest, which is the flow direction of rising tide. It accords with the phenomenon that width gradually expands in both sides of the deep channels near Bitou area and water depth is stable and increases a little, mainly in equilibrium with a bit more scouring.

Key words: Xinghua bay, sediment characteristics, sediment concentration, water and sediment transport, topography evolution, tide