根据对2011年8月在江苏海岸与长江口北支岸线交界点处的圆陀角附近砂质海滩采集的表层沉积物样品进行粒度分析,获得了平均粒径、分选系数、峰态、偏态等粒度参数数据,结果显示该处沉积物类型以细砂级为主,分选性较好,正偏。运用Gao—Collins二维沉积物粒径趋势分析模型模拟出沉积物净输运趋势发现:圆陀角附近砂质海滩的表层沉积物整体呈由海向岸输移的趋势,其中潮水沟中的沉积物粒径趋势比较显著,受地形影响,靠岸区域沉积物有自岸向海输移的趋势。而通过对圆陀角近岸海域一系列沙坝遥感影像的提取分析,发现沙坝的发育走向基本与海岸线方向平行,且前端都发育有沙嘴,并不断向东南方向延伸。
Based on the grain size analysis of the surface sediments sampled in August, 2011 at the sandy beach close to the Yuantuojiao Point, the sediments distribution pattern and sands transportation trend were discussed in this paper. The Yuantuojiao Point is located at the transition site between the north branch of the Yangtze River and the Jiangsu coast, and experienced rapid sedimentation in the past dec- ades. The grain size data, such as the mean grain size, sorting coefficient, skewness and kurtosis, were an- alyzed. The results showed that the sediments were mainly composed of well sorted fine sand with positive skewness. The grain size data was processed using the Gao-Collins model for the purpose of grain size trend analysis. It is found that the sandy beach sediments were transported from sea to the shore in general and the sediment transport trend is strongly influenced by topography. In front of the dike, sediments are transported to the sea. And through the analysis of a series of remote sensing images of the bar near the Yuantuojiao Point, we found that the extending direction of the bar is parallel to the coastline. There is a spit developing in the front of the bar, extending to the southeast.