Empirical parameterizations of the shortwave sand transport that are used in practical engineering models lack the representation of certain processes to accurately predict morphodynamics in shallow water. Therefore, measurements of near‐bed velocity and suspended sand concentration, collected during two field campaigns (at the Sand Engine and Ameland, the Netherlands) and one field‐scale laboratory experiment (BARDEXII), were here analyzed to study the magnitude and direction of the shortwave sand flux in the shallow surf zone. Shortwave sand fluxes dominated the total sand flux during low‐energetic accretive conditions, while the mean cross‐shore current (undertow) dominated the total flux during high‐energetic erosive conditions. Under low‐energetic conditions, the onshore‐directed shortwave sand flux scales with the root‐mean‐square orbital velocity urms and velocity asymmetry Au but not with the velocity skewness. Under more energetic conditions the shortwave flux reduces with an increase in the cross‐shore mean current and can even become offshore directed. For all data combined, the contribution of the shortwave flux to the total flux scales with , with a high contribution of the shortwave flux (∼70%) when this ratio is high (∼ 10) and low contributions (∼0%) when this ratio is low (∼1). We argue that the velocity asymmetry is a good proxy for the net effect of several transport mechanisms in the shallow surf zone, including breaking‐induced turbulence. These field and laboratory measurements under irregular waves thus support the hypothesis that the inclusion of velocity asymmetry in transport formulations would improve the performance of morphodynamic models in shallow water.

中文翻译：

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浅海区的短波沙运

实际工程模型中使用的短波输沙经验参数化缺乏某些过程的表示，无法准确预测浅水中的形态动力学。因此，对两次现场活动（在荷兰的 Sand Engine 和 Ameland）和一次现场规模实验室实验（BARDEXII）期间收集的近床速度和悬浮沙浓度的测量结果进行了分析，以研究沙子的大小和方向。浅海区的短波沙通量。在低能增生条件下，短波沙通量主导了总沙通量，而在高能侵蚀条件下，平均横岸流（潜流）主导了总通量。低能条件下，陆上定向短波沙通量与均方根轨道速度成比例你有效值和速度不对称A你但与速度偏度无关。在能量更高的条件下，短波通量随着横岸平均电流的增加而减少甚至可以成为海上导向。对于所有数据的组合，短波通量对总通量的贡献与，当该比率较高（∼ 10）时，短波通量的贡献较高（∼70%）；当该比率较低（∼1）时，短波通量的贡献较低（∼0%）。我们认为，速度不对称性可以很好地代表浅海区几种传输机制的净效应，包括破碎引起的湍流。因此，这些不规则波浪下的现场和实验室测量结果支持了这样的假设：在传输公式中包含速度不对称性将提高浅水中形态动力学模型的性能。