长江口动水絮凝沉降与拦门沙淤积的关系

根据１９８２年４月－１９８３年３月长江口南槽３个站位全年逐月大湖的水化学成分、悬沙粒度与粘土矿物资料，１９８４－１９９２年在环形水槽中获得的近百个组次的动水絮凝沉降试验研究资料，以及长江口细颗粒泥沙、浮泥与底质研究成果，对拦门沙形成过程及其机理进行综合研究。

THE RELATIONSHIP BETWEEN FLOCCULATING SETTLEMENT IN FLOWING WATER AND DEPOSITION IN THE CHANGJIANG RIVER ESTUARY MOUTH BAR AREA

Based on the water chemical components, the suspended grain size and clayminerals data in the Changjiang River Estuary South Channel, every springtide fromApril, 1983 to March, 1984, and about a hundred flocculating settlement test dataon flowing water, which were undertaken in the circle water channel from 1984 to1992, and the results of study on the fine sediments, fluid mud and bottom. sedim-ents, the formingprocess and mechanism of mouth bar were comprehensively studied.It was shown that the mouth bar is the youngest active delta in the ChangjiangRiver Estuary during the flood season, while the area where the Changjiang runoffand Taiwan warm current meet off the Changjiang Estuary was the strongest floccu-lating settlement and most active fluid mud development. The illites and kaolinitesare flocculated and deposited at the salt water wedgehead where the water salinityis about 9 X 10-3-13 X 10-3 during flood time and the montmorillionites are floc-cu1ated and deposited in the salt water wedgetail where the water salinity is aboutl9 X 10-3-24 X 10-3 during the ebb time, which show the essential regularities ofthe horizontal deposition in the mouth bar area. The fluid mud lens which growsand declines in a semi-month cycle produces a coarse and medium silt relic lens and.beddings, which show the essential regularities of vertica1 ccumuItion in ChngjingRiver Estury mouth bar are. The above findings provide the scientific base for thecomprehensive mangement and deep waterway desingand uses of mouth bar.