近年来,长江口北支中段新村沙整治和海门中下段围垦等工程的实施,使北支河宽不断缩窄,边界条件发生了变化,径潮流动力条件也随之发生变化。为了解近期北支涌潮的特性,采用自记潮位仪采集潮位数据、人工岸边观测潮头、抛设浮标观测流速以及快艇迎潮头(潮头追快艇)的形式观测涌潮。结果表明:涌潮主要发生在浅滩区域,包括青龙港上游及崇海汽渡上游浅滩处,涌潮高度分别约为0.63 m和0.74 m,在灵甸沙至崇海汽渡上游浅滩仍然存在一线潮现象。掌握涌潮生成、增强、衰弱及消失的大概位置,分析涌潮成因、形态和特点,能够为深入研究北支中上段河床冲淤变化与其特殊水动力条件间的相互作用机理提供基础资料,进而为稳定北支河势、合理开发利用北支航道提供技术支撑。

In recent years, the implementation of many projects in the north branch of the Yangtze River estuary, such as the regulation project of Xincun shoal and the reclamation project in the middle and lower reach of Haimen reach, have narrowed the river width, changed the boundary condition and river-tidal dynamics of the north branch. In the aim of understanding the characteristics of tidal bores in the north branch, we observed the tidal bores by collecting tide level using self-recording tide gauge, visually observing tide rip on bank, observing flow velocity by buoys, and observing tidal bores on speed boat. We found that tidal bore mainly happens in shallow shoal area including the upper reach of Qinglong harbor and Chonghai ferry dock, with the height of tidal bore reaching 0.63 m and 0.74 m, respectively. In addition, one-line bore still exists in the reach from Lingdian shoal to the upstream shoals of Chonghai ferry dock. By recording the approximate locations of tidal bore’s generation, development, damping and vanishing, and analyzing the origin, type and characteristics of tidal bore, we can provide basic data for researching the interactions between river bed erosion/deposition and special hydrodynamic conditions in the middle and upper reaches of the north branch, and also would offer technical support for further stabilizing the river regime and utilizing the navigation channel in the north branch reasonably.