南黄海辐射沙洲附近海域悬浮体的研究

对2003年春季(3-4月)和秋季(9月)南黄海辐射沙洲附近海域的悬浮体样品进行了空间分布特征、有机无机组成、粒度特征及其季节变化分析。结果表明:(1)2003年春季研究区内悬浮体浓度要普遍高于秋季的悬浮体浓度。悬浮体浓度最高值区位于长江口-老黄河口之间的近岸区。陆源物质为主的无机组分是悬浮体的主体成分,特别是在近岸浅水区和接近海底的底层水中尤为突出;(2)研究区海水中的悬浮体主要来源于辐射沙脊区(老黄河-长江复合三角洲)沉积物再悬浮;(3)悬浮体分布是风浪、潮流及沿岸流等多种因素综合作用的结果,而风浪和潮流是影响本区悬浮体分布的主要因素,巨大的风浪和强大的潮流造成辐射沙洲海底的沉积物再悬浮、搬运和再沉积,并在苏北沿岸流的作用下向沙洲外缘输运。

SUSPENDED SEDIMENT NEAR RADIAL SAND RIDGE AREA IN THE SOUTH YELLOW SEA

Based on suspended sediment samples investigated near radial sand ridge area in the South Yellow Sea during spring(March-April) and autumn(September) 2003,spatial distribution characteristics,organic-mineral component,grain sizes and their seasonal changes were analyzed.The results show that suspended sediment concentration(SSC) has higher values in spring than in autumn,and high SSC occurs in the near-bottom layer in both of the seasons;the nearshore area has higher SSC than the offshore;SSC of coarse grain size occurs within the sand ridge area,while the fine appears in the periphery of the sand ridges in the seasons. Suspended sediments in the study area mainly stem from resuspending of the submarine sediment in the radial sand ridges(old Yellow-Yangtze River multiple delta). The distribution of SSC is mainly affected by wind-induced wave,tidal current and alongshore current,etc.and it is the result of interactions of these factors.The wind-induced wave and tidal current are the main factors affecting the distribution of SSC in the study area.Strong wind-induced waves and tidal currents cause submarine sediment in the sand ridge area to resuspend,redeposit and transport toward the periphery of the sand ridges.