三亚红塘湾海域海床表层沉积物及泥沙运动特征

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

根据红塘湾海域不同时期海床表层沉积物资料,分析研究该海域表层沉积物分布与泥沙运动特征。结果显示:该海域近岸海床表层泥沙颗粒较粗,主要以中粗砂和粗中砂为主;5~10m等深线之间,底质以中砂和中细砂为主;10~12 m等深线附近以细砂为主,12m等深线以外底质主要为粉砂和黏土类;底质泥沙颗粒从岸向海逐渐变细。在波流共同作用下,当地泥沙较易起动,波浪对泥沙运动起到关键性作用;该岸段沿岸输沙量级不大,而且保持相对稳定状态,其输沙性质与弧形海岸的动力环境和地形特征相一致。目前各段海岸泥沙运动近似于动态平衡,没有大规模的冲刷和堆积现象。

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 min water depth;（3）fine sand dominates the area of 10 ~ 12 min depth,while in the area deeper than 12 m,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.