Shoreline Instability due to Very Oblique Wave Incidence: Some Remarks on the Physics
Shoreline Instability due to Very Oblique Wave Incidence: Some Remarks on the Physics
复制标题
非常斜波入射引起的海岸线不稳定性：对物理学的一些评论
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
F. Ribas
中科院分区：
文献类型：
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作者：
A. Falqués;D. Calvete;F. Ribas
以往的研究表明，非常倾斜的波浪入射海岸可能使直线海岸线不稳定。在这里，我们对这种不稳定性的物理现象提出了一些进一步的见解。波浪入射角对岸线漂移有两个影响：(1)直接影响波锋与岸线之间的相对角度；(2)通过波浪靠近海岸时折射的波浪能量传播，间接影响破浪高度。结果表明，在所有事件中，直接效应都是稳定的，而不稳定仅来自波能传播的影响，而波能传播在大入射角下起主导作用。而早期的研究只指出沿岸漂移是不稳定的原因，我们表明不稳定机制涉及冲浪区和浅滩区，因此由跨岸沉积物运输提供的联系也是必不可少的。
Abstract Previous research has shown that a very oblique wave incidence on a coast may render a rectilinear shoreline unstable. Here, we present some further insight into the physics of such instability. The obliqueness of wave incidence has two effects on the alongshore drift: (i) a direct effect on the relative angle between the wave fronts and the shoreline, and (ii) an indirect effect on the breakers height via the wave energy spreading as the waves refract when they approach the shore. The direct effect turns out to be, in all incidents, stabilizing, and the instability occurs only from the effects of the wave energy spreading, which dominate for large incidence angles. Whereas earlier studies have pointed only to the alongshore drift as the cause of the instability, we show that the instability mechanism involves both the surf and the shoaling zones, so that the link provided by the cross-shore sediment transport is also essential.