华东师范大学学报(自然科学版) ›› 2003, Vol. 2003 ›› Issue (2): 74-80.

• 论文 • 上一篇    下一篇

长江口北支的涌潮及其对河口的影响

陈沈良； 陈吉余；谷国传   

  1. 华东师范大学 河口海岸国家重点实验室， 上海 200062
  • 收稿日期:2001-12-03 修回日期:2002-06-09 出版日期:2003-04-15 发布日期:2003-04-15

The Tidal Bore on the North Banch of Changjiang Estuary and Its Effects on the Estuary

CHEN Shen-liang; CHEN Ji-yu; GU Guo-chuan

  

  1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
  • Received:2001-12-03 Revised:2002-06-09 Online:2003-04-15 Published:2003-04-15

摘要： 根据限产踏勘，实测并结合历史资料，阐述了长江口北支涌潮的发育，种类，形态和特点，并利用流体水跃现象的Froude 数判别，解释了涌潮成因。进一步研究表明，河槽束狭加大涨潮流速，河床淤浅则减缓潮波传速。北支在自然和人为的影响下，河槽不断束狭，河床逐渐淤浅是近年来涌潮发生次数增多，潮头增大的原因。随着涌潮潮头的推进，大量水沙上溯，这对北支和南支上段的滩，漕变化和河口环境有着深刻的影响。

关键词: 涌潮, 潮波传播, 水沙倒灌, 长江口北支, 涌潮, 潮波传播, 水沙倒灌, 长江口北支

Abstract: The development,characteristics and cause of the tidal bore on the North Branch of Changjiang Estuary are expounded based on survey and measured data. The hydraulic jump can be distinguished using the Froude number. When the fliid tidal current velocity exceeds the propagation velocity of tidal wave, the water particles transfer the kinetic energy to the potential energy, therefore the water level abruptly jump and forms bore. Further analysis suggests that narrowed river channel increase flood current velocity and silted riverbed slows down tidal wave propagation velocity. The river channel of the North Branch of Changjiang Estuary has been narrowed and its bed has been silted for recent years because of natural processes and artificial actions, which are the main causes of increased bore frequency and strength. With the bore head advance, a great amount of saltwater and sediments flow upstream. It has profound effects on the river channel evolution and environment of the estuary.

Key words: tidal wave propagation, saltwater and sediment flow backward, North Branch of Changjiang Estuary, tidal bore, tidal wave propagation, saltwater and sediment flow backward, North Branch of Changjiang Estuary