长江口北槽最大浑浊带泥沙过程  

Fine Sediment Transport in Turbidity Maximum at the North Passage of the Changjiang Estuary

作　　者：时钟[1] 陈伟民 

机构地区：[1]上海交通大学港口与海岸工程系,上海200030

出　　处：《泥沙研究》2000年第1期28-29,共2页Journal of Sediment Research

基　　金：国家自然科学基金!(49806005) ;国家教育部"跨世纪优秀人才培养计划"基金!( 教技函[1999]2 号)

摘　　要：利用长江口北槽口内和口外大潮和小潮的流速、盐度和含沙量资料，对北槽最大浑浊带水动力、泥沙过程及成因机制进行了分析和研究。此外，还利用一维悬沙数学模型对北槽的悬沙过程进行了模拟。研究结果表明：在北槽口内，最大浑浊带形成的主要动力过程是潮汐的不对称性和河口重力环流。在北槽口外，最大浑浊带形成的主要动力过程则是河口底部泥沙的周期性再悬浮。在长江口北槽口内、口外最大浑浊带中，细颗粒泥沙的再悬浮过程也存在着一定的周期性。此外，由盐度、悬沙浓度层化引起的“层化抑制紊流”也是长江口北槽口内、口外最大浑浊带的成因机制之一。长江口北槽口内和口外水动力悬沙过程的差异性在一维数学模拟的结果中也得到了证实。Using the velocity, salinity and suspended sediment concentration data obtained at spring and neap tides at two ends (head and mouth) of the North Passage of the Changjiang Estuary, this paper analyses the hydrodynamic and sediment transport processes in the turbidity maximum there. Furthermore, the vertical profiles of fine suspension concentration at the North Passage are simulated by using 1DV suspended sediment transport model. Results suggest that the dominant dynamic processes responsible for the formation of the turbidity maximum are tidal asymmetry and gravitational circulation at the mouth of the North Passage. While the dominant dynamic processes responsible for the formation of the turbidity maximum are near bed periodic resuspension at the head of the North Passage. In addition, “turbulence suppression by salinity and suspension stratifications” is one of the important mechanisms for the formation of the turbidity maximum at the North Passage. Differences of hydrodynamic and suspended sediment processes at two ends of the North Passage are also confirmed by the mathematical modeling results.

关 键 词：长江口 最大浑浊带 潮汐不对称性 泥沙过程 

分 类 号：TV148.1[水利工程—水力学及河流动力学]