| 摘要: |
| 依据1988年7月和12月水文观测资料，通过流、盐、沙的综合分析，认识到长江口拦门沙地区的泥沙运动有与河口其他地区不同的特点。泥沙输移在水平面上和垂直面上存在着多种循环；潮流和盐水截留大量泥沙积聚在拦门沙地区；河口在盐淡水交锋地带，除了涨、落急时段外，发现在转流时期泥砂也可能产生再悬浮，从而形成一个潮周期中出现3次或4次再悬浮的特殊规律。 |
| 关键词: 长江河口 拦门沙 泥沙运动 泥沙再悬浮 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金重大项目资助，9487005号 |
附件 |
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| THE SEDHVIENT DYNAMICS IN THE CHANGJIANG RIVER ESTUARY MOUTH BAR AREA |
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Pan Dingan, Sun Jiemin
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Institute of Estuarine and Coastal Research, East China Normal University, Shanghai 200062
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| Abstract: |
| Results analyzed current, salt, sediment based on hydrographic data of Changjiang River mouth bar in July and December, 1988 were as follow. In the
Changjiang River Estuary mouth bar area sediment in the reach where runoff plays an important role moves seaward; sediment in the reach where tidal current is the main force, moves landward; sediments in the reach where density current plays an important role circulates vertically; and the sediment on the whole circulates in a plane under the impacts of the topography and current.
The abundant sediment discharged from the Changjiang River are trapped at the mouth bar due to the effects of tidal current, runoff, and mixing of salt and fresh-water. There are two different mechanisms controlling the trapping of the sediment by tidal current and salt water. The depositing centre may not be at one place but in two densely depositing zones in the deep trough.
It was found that the sediment of the mixing zone between salt and fresh-water was resuspended three or four times during one tidal period. The reason is related to the mixing effect between salt water and fresh water. |
| Key words: Changjiang River Estuary, Mouth bar, Sediment motion, Sediment resupended |
