悬浮体粒度特征所反映的南黄海辐射沙脊群泥沙扩散趋势

基于大量的悬浮体现场粒度和浓度数据，借助细颗粒悬浮体作为示踪物，分析了潮流作用下南黄海辐射沙脊群海底沉积物的再悬浮和扩散特征，并探讨了沙辐射沙脊群以北泥质区的形成机制。研究结果表明：（1）在辐射沙脊群以北，近岸悬沙在离岸方向上的扩散受到限制，向南又被辐射沙脊群中心浅滩所阻挡，只能在辐射沙脊群与废黄河口之间形成沿岸分布的高浓度浑水团。（2）辐射沙脊群以北的往复潮流对海底沉积物有分选作用，倾向于把海底沉积物中的粗颗粒分选搬运至沙脊群，把细颗粒沉积物向北输送，从而在沙脊群以北形成泥质区。（3）在正常海况下，沙脊表层沉积物再悬浮作用十分微弱，沙脊上覆水体中的悬沙主要来自于临近沟槽海底沉积物的水平扩散。

The diffusion of sediment in radial sand ridges in Southern Yellow Sea-an analysis from grain size characteristic of suspended particles

Mainly based on the data of suspended partilce grain size and using the fine suspended partiles as indicater of suspended sediment diffusion ,the characteristic of sea bed sediment resuspending and diffusion in radial sand ridges of Southern Yellow Sea is analyzed . The main conclusions are summarized as below : (1) Between the radial sand ridges and the abanded Yellow River delta, the suspended sediment is restricted within the shallow water and can only be transported along the coast by rectilinear tidal current. The changing of tidal process across seaward direction might be the main reason.(2) The rectilinear tidal current over northern radial sand ridges can play a role of sorting sea bed sediment, which trend to tansported coarse partilces to sand ridges area and fine particles northward. (3) in the area outside the turbid plume , the surface sediment on sand ridges is too coarse to be resuspended by normal tidal current, the suspend matters in water column above these sand ridges are mainly transported from adjacent channels by convection .