The mutual feedback between the swash zone and the surf zone is known to affect large-scale morphodynamic processes such as breaker bar migration on sandy beaches. To fully resolve this feedback in a process-based manner, the morphodynamics in the swash zone and due to swash-swash interactions must be explicitly solved, e.g., by means of a wave-resolving numerical model. Currently, few existing models are able to fully resolve the complex morphodynamics in the swash zone, and none is practically applicable for engineering purposes. This work aims at improving the numerical modelling of the intra-wave sediment transport on sandy beaches in an open-source wave-resolving hydro-morphodynamic framework (e.g., non-hydrostatic XBeach). A transport equation for the intra-wave suspended sediment concentration, including an erosion and a deposition rate, is newly implemented in the model. Two laboratory experiments involving isolated waves and wave trains are simulated to analyse the performance of the model. Numerical results show overall better performance in simulating single waves rather than wave trains. For the latter, the modelling of the morphodynamic response improves in the swash zone compared with the existing sediment transport modelling approach within non-hydrostatic XBeach, while the need of including additional physical processes to better capture sediment transport and bed evolution in the surf zone is highlighted in the paper.

已知斜流区和冲浪区之间的相互反馈会影响大规模的形态动力学过程，例如破碎杆在沙滩上的迁移。为了以基于过程的方式完全解决该反馈，必须明确地解决斜率区域中以及由于斜率-斜率相互作用而引起的形态动力学问题，例如借助波动解析数值模型。当前，很少有现有的模型能够完全解决斜波带中复杂的形态动力学，并且没有一个模型可实际用于工程目的。这项工作的目的是在开放源代码解析水动力形态动力学框架（例如非静水XBeach）中改进沙滩内波浪内沉积物传输的数值模型。波内悬浮沉积物浓度的输运方程，包括侵蚀和沉积速率，在模型中新实现。模拟了两个涉及隔离波和波列的实验室实验，以分析该模型的性能。数值结果表明，在模拟单波而不是波列时，总体上具有更好的性能。对于后者，与非静水XBeach中现有的泥沙运移建模方法相比，斜流区的地貌动力响应建模得到了改善，同时还需要包括其他物理过程以更好地捕获海浪区的泥沙运移和床层演化。在论文中突出显示。