夏、冬季苏北近岸海域悬沙浓度垂直分布特征

The characteristics of vertical distribution of suspended sediment concentration in inshore waters of northern Jiangsu in summer and winter

通过将2012年8月、12月在苏北黄海海域野外调查获得的声学多普勒流速剖面仪(ADCP)后向散射强度数据与悬沙浓度进行拟合,得知两者的相关系数在0.8以上,反演结果较理想。并结合同步观测的温度、盐度等水文要素资料,对该区域夏、冬季两季悬浮泥沙的垂直分布特征、形成原因及输运进行了研究,结果表明苏北近岸海域悬浮泥沙分布的典型性季节变化明显,冬季悬沙浓度普遍高于夏季。悬浮泥沙分布及输运受苏北沿岸水、黄海西部沿岸流、长江冲淡水、黄海暖流、黄海冷水团等影响,其中黄海西部沿岸流的季节变化为主要的影响因素。苏北沿岸水携带废黄河口的再悬浮泥沙和近岸悬沙向东南外海扩散,冬季的搬运量和扩散范围显著大于夏季。黄海暖流阻碍悬沙向外海扩散,使其在近岸被大量捕集下来。夏季长江冲淡水的东北方向偏转,使得苏北南部海域悬沙分布出现层化现象。

Through fitting the Acoustic Doppler Current Profiler（ ADCP） backscatter intensity data obtained by field survey and suspended sediment concentration in Jiangsu Yellow Sea in August and December 2012,we learned that the correlation coefficient was 0. 8 or more,the inversion results were ideal. Combined with the simultaneous observation of the hydrological data such as temperature,salinity,we studied vertical distribution of suspended sediment transport characteristics,formative causes of two seasons of summer and winter in the region. The results show that Jiangsu typical seasonal variation of suspended sediment distribution in nearshore waters was obvious,and suspended sediment concentration was generally higher in winter than in summer. The distribution and transportation of suspended sediment were affected by Subei coastal water,western Yellow Sea coastal currents,Yangtze diluted water,Yellow Sea warm current,Yellow Sea cold water mass and other factors,in which seasonal variation of western Yellow Sea coastal currents were its main influence factors. Subei coastal water carrying the resuspended sediment in Yellow River estuary and nearshore suspended sediment spread to the south-east coast,and the transportation amount and diffusion range is larger in winter than in summer. Warm currents of Yellow Sea prevented suspended sediment from outward diffusion,which was captured in nearshore. Northeasterly direction deflection of Yangtze diluted water caused the distribution stratification phenomenon of suspended sediment in southern Subei in summer.