Coupled swash zone hydrodynamics and beach morphodynamics modeling . Model establishment & validation
Based on the one-dimensional nonlinear shallow water equations and the bed deformation equation, this study considers two types (a total of six) of different sediment transport rate formulas, and implants the bed shear stress and seepage source terms to the equations, and finally a more complete model of swash zone hydrodynamics and beach morphodynamics is proposed, in which a coupled solution was realized. The model reliability is numerically verified based on the classical benchmark. The verification results show that the TVD-WAF format and the segmental sand transport rate formula used in the proposed coupling model have achieved good solutions in numerical accuracy and morphological changes, which are better than previous research results. On this basis, this model is used to carry out numerical investigation of smash zone hydrodynamics and beach profile evolution. The results of depth, shoreline trajectory and shore- line profile are in good agreement with the experimental results, and then the study focused on the effects of different friction coefficients and the presence of seepage on beach morphologies. The results indicate that the segmental sediment transport rate formula proposed in this study is suitable for the study of sediment transport in the swash zone, and the effects of bed friction and seepage should not be ignored during established the beach morphodynamics model of swash zone.