长江口南汇边滩的演变及其沉积动力机制  

Geomorphic Evolution of Nanhui Nearshore of the Yangtze Estuary and Its Sediment Dynamic Mechanism

作　　者：陈沈良[1] 张国安[1] 谷国传[1] 

机构地区：[1]华东师范大学河口海岸国家重点实验室,上海200062

出　　处：《上海地质》2003年第4期1-4,共4页

基　　金：国家自然科学基金(批准号 :4 0 2 76 0 2 7)

摘　　要：南汇边滩是长江口、杭州湾以及外海三者交互作用的特殊地带。根据不同时期海图对比分析发现 ,南汇边滩北冲南淤 ,逐渐向东南方向伸展 ,平均速率为 30m/a。通过初步的机制探讨认为 ,南汇边滩有径流输沙和涨潮回输泥沙的双重补给 ,加上适宜盐度的絮凝 ,沉积速率较大 ,在滩面淤高的同时向水平方向扩展 ,但北侧受南槽落潮水流南偏的作用而不断冲刷 ,东侧突出的沙嘴受外海风浪的强烈作用难以东扩 ,南侧受杭州湾口近东西向的涨落潮流作用 ,在这些动力泥沙的综合作用下 。Nanhui nearshore is situated in a special area of the Yangtze Estuary, Hangzhou Bay and sea interactions. The comparison of sea charts show that the nearshore has extended toward southeast with the rate of 30m/a。The sediments of Nanhui nearshore are supplied from river discharge and flood current. There the deposition rate is high due to fine sediment flocculation. The nearshore extends horizontally with its accumulation. However, its north is suffered from scoring due to strong discharge current of South Channel, its east is suffered from the action of wind waves, and its south is suffered from tidal currents of Hangzhou Bay. These combined actions of dynamics result in Nanhui nearshore extending southeastward.

关 键 词：南汇边滩 冲淤演变 沉积动力 机制 

分 类 号：P736.212[天文地球—海洋地质]