中文摘要：

以存在缓变背景流的二维缓坡方程为控制方程建立一个计算模型来研究大亚湾长周期波的传播规律。按入射波源形式不同、周期不同和有无背景潮流设计了几个数学试验，分别通过这几个试验研究长周期波传播规律。从模拟结果发现，在大亚湾水域，仅在开边界附近不同源形式的入射波对波浪传播的影响有所变化；总的来说，从入射点到湾内波高削弱较快，但是对于不同周期的入射波，模拟所得波高分布变化较大；对于长周期的入射波，背景流也对波浪传播有一定影响。

英文摘要：

Based on the two-dimensional mild-slope difference equation with varying background current, a numerical model is set up and employed to study the long-period wave propagation in the Daya Bay. Several numerical experiments, including different source forms and periods for incident waves, with or without background tidal current, etc. , are carried out respectively. It is shown that only near the open boundary does the difference between the line source and dot source incident waves have influence on wave propagation in the Daya Bay. The wave heights attenuate quickly from the source site and middle bay to the coastal waters; however, their distributions may be very different for the incident waves of different periods. The background current also has a little effect on the wave propagation for the incident wave of larger period.