CHARACTERISTICS AND TRANSPORTATION OF SURFACE SEDIMENTS IN HONGTANG BAY OF SANYA, HAINAN ISLAND

Distribution and transportation of surface sediments are analyzed in this paper based on grain size data. Results show that: (1) bottom sediment particle is generally getting finer from land to sea. Within the water depth of 5 m, coarse sand and coarse-medium sand dominate; (2) the sediment is mainly medium sand and fine sand in the area between 5 - 10 m in water depth; (3) fine sand dominates the area of 10 ~ 12 m in depth, while in the area deeper than 12m, silt and clay dominate. Waves play a key role in initiation of sediment moving. Under the action of wave flow, sediments are easy to start moving. Longshore sediment transportation is limited, but remains in a relatively stable status. The sediment transport is consistent with the hydrodynamic and topographic features. At present, the sediment is under a status of dynamic balance and no large-scale erosion and/or deposition is expectable.