摘要
根据对北黄海西部海底沉积物的粒度测试 ,运用“粒度趋势分析”方法 ,分析探讨了北黄海西部 (渤海海峡区 )海底表层底质的粒度分布特征和净输运趋势。结果表明 ,本区的细颗粒沉积物主要位于北黄海中部和山东半岛沿岸、大连湾附近 ,粗颗粒沉积物则主要分布于庙岛群岛以东和大连湾东南侧海区。沉积物的平均粒径、分选系数、偏态系数等粒度参数的分布特征有一定的对应性。除庙岛群岛东侧的砂质沉积 ,分选较好之外 ,其它海区的沉积物总体特征是 ,粒径越粗 ,分选越差 ,偏态更正偏 ;而粒径越细 ,分选越好 ,偏态系数也较低。山东半岛北侧的沉积物具有向东和向东北的输运趋势 ,西部沉积物的输运趋势向东南并转向东 ,北部沉积物的输运趋势向南 ,形成了向北黄海中部汇聚的趋势。本项研究还表明“粒度趋势分析”方法在大范围的陆架区域具有较好的适用性。在操作中 ,使用规则的正方形网格可以较全面判断、合成趋势矢量 ;进行高密度的采样有助于揭示沉积物净输运趋势的细节特征。
It is important to identify net sediment transport characteristics of the northern Yellow Sea, in order to understand the processes of material exchange between the Bohai and Yellow Seas. In this study, grain size trend analysis was carried out to delineate net sediment transport patterns of the region using the samples collected during the cruise in September, 1998. As a secondary objective, the applicability of grain size trend analysis to large scale areas on continental shelf environments is discussed.\;The results indicate that grain size parameters have some distinct patterns in spatial distributions in the study area. Except for the sand which are well sorted to the eastern of Miaodiao Isands, the sediments with coarser sizes are poorly sorted and highly positively skewed, and the sediments with finer sizes are better sorted with lower skewness. Sediments along the northern coast of Shandong Peninsula are transported towards the east or northeast. In the central area, net deposition is taking place, as indicated by the convergence of the grain size trends. This result is consistent with previous observations about the Yellow River sediment transport from the south channel of Bohai Strait, and the current circulation pattern over the northern Yellow Sea. The present research indicates the validity of grain size trend analysis for large scale areas of continental shelves. Sufficiently short sampling distance is necessary to delineate the detailed transport patterns and a uniform (grid iron) sampling grid is better to assess the directions of transport vectors. It should be noted that the transport vector contains information on transport direction, rather than the magnitude of transport rate.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2000年第6期604-615,共12页
Oceanologia Et Limnologia Sinica
基金
中国科学院重点资助项目 !KZ952 -J1 -4 0 6号
国家自然科学基金资助项目 !4 98760 1 8号
关键词
粒度特征
粒度趋势分析
沉积物
北黄海
净输运
Grain size characteristics\ \ Grain size trends analysis\ \ Sediment transport\ \ North Yellow SeaD
