丁字湾近岸海域表层沉积物粒度特征及沉积动力环境

Grain size characteristics and dynamic environment of surface sediments on the near shore seabed of Dingzi Bay

根据丁字湾近岸海域126个表层沉积物样品粒度分析结果,对沉积物类型和粒度参数分布进行了总结。在此基础上,利用粒径趋势分析模型(GSTA)和沉积动力判别图解,探讨了表层沉积物的运移趋势及沉积水动力规律。结果表明,丁字湾近岸海域表层沉积物类型共有8种,其中砂、砂质粉砂和粉砂分布最广泛;平均粒径具有从岸向海逐渐变细的特征,分选性、偏度和峰度分别具有较差—差、正偏—极正偏、中等的特征;粒度运移趋势分析反映出湾口海岸附近泥沙由两侧向湾口中心运移,远离海岸泥沙由北西向南东偏东方向运移;沉积动力判别图解揭示出丁字湾海域沉积水动力具有整体较强,由岸向海方向逐渐减弱的特征。

126 surface sediment samples were collected from the near shore seabed of Dingzi Bay in Shandong province for grain size analysis.Grain size parameters of the samples are calculated and sediment types determined.Upon the basis,sediment transport trends were studied using the Gao-Collins Grain Size Trend Analysis(GSTA model).Sedimentary hydrodynamics was defined using Pejrup triangular diagram.Results indicate that there are eight types of sediments in the bay,dominated by sand,sandy silt and silt.The sediments,in general,are getting finer from the shore to the ocean.They are poorly and very poorly sorted,positively and very positively skewed,and moderate in kurtosis.There are two kinds of sediment transport patterns.In the area near the shoreline,the sediment is transported from the coast to the center of the bay,while in the offshore area,sediment moves from the northwest to southeast.Relatively strong sedimentary hydrodynamics occur in the coastal area.It becomes weaker when water gets deeper.