Abstract
In this paper, the two common approaches to account for wave randomness, the spectral approach and the wave-by-wave approach, are compared through numerical experiments conducted with the coupling of a surf zone hydrodynamic model and a bedload sediment transport model. Special attention is paid to the wave nonlinearity and net cross-shore bedload transport predictions. The two approaches are found to have negligible difference in their predictions of certain average hydrodynamics, such as wave heights, set-up and undertow. However, the wave-by-wave approach outperforms the spectral approach in the wave nonlinearity prediction, and the two approaches differ significantly in their predictions of wave-induced net cross-shore bedload transport which strongly depends on wave nonlinearity. This suggests the necessity of using the wave-by-wave approach. The computational efficiency of the wave-by-wave approach is also discussed.References
Dally, W. R. 1992. Random breaking waves: Field verification of a wave-by-wave algorithm for engineering application. Coastal Engineering, 16(4), 369-397. http://dx.doi.org/10.1016/0378-3839(92)90060-8
Dally, W. R. and Dean, R. G. 1986. Transformation of random breaking waves on surf beat, Proceedings of the 20th International Conference on Coastal Engineering, ASCE, 109-123.
Gonzalez-Rodriguez, D. and Madsen, O. S. 2007. Seabed shear stress and bedload transport due to asymmetric and skewed waves. Coastal Engineering, 54(12), 914-929. http://dx.doi.org/10.1016/j.coastaleng.2007.06.004
Gonzalez-Rodriguez, D. and Madsen, O. S. 2010. An analytical model to predict bedload transport in oscillating water tunnels, Proceedings of the 32nd International Conference on Coastal Engineering, ASCE. (this issue)
Grasmeijer, B. T. and Ruessink, B. G. 2003. Modeling of waves and currents in the nearshore parametric vs. probabilistic approach. Coastal Engineering, 49(3), 185-207. http://dx.doi.org/10.1016/S0378-3839(03)00045-0
Herrmann, M. J. and Madsen, O. S. 2007. Effect of stratification due to suspended sand on velocity and concentration distribution in unidirectional flows. Journal of Geophysical Research, 112(C2), C02006. http://dx.doi.org/10.1029/2006JC003569
Madsen, O. S. 1991. Mechanics of cohesionless sediment transport in coastal waters, Proceedings of Coastal Sediments' 91, 15-27.
Madsen, O. S. 1994. Spectral wave-current bottom boundary layer flows, Proceedings of the 24th International Conference on Coastal Engineering, ASCE, 384-398.
Mase, H. and Iwagaki, Y. 1982. Wave height distributions and wave grouping in surf zone, Proceedings of the 8th International Conference on Coastal Engineering, ASCE, 58-76.
Mizuguchi, M. 1982. Individual wave analysis of irregular wave deformation in the nearshore zone, Proceedings of the 8th International Conference on Coastal Engineering, ASCE, 485-504.
Tajima, Y. and Madsen, O. S. 2006. Modeling Near-Shore Waves, Surface Rollers, and Undertow Velocity Profiles. Journal of Waterway, Port, Coastal, and Ocean Engineering, 132(6), 429-438. http://dx.doi.org/10.1061/(ASCE)0733-950X(2006)132:6(429)
Thornton, E. B. and Guza, R. T. 1983. Transformation of wave height Distribution. Journal of Geophysical Research, 88(C10), 5925-5938. http://dx.doi.org/10.1029/JC088iC10p05925
Van Rijn, L. C. and Wijnberg, K. M. 1996. One-dimensional modelling of individual waves and waveinduced longshore currents in the surf zone. Coastal Engineering, 28(1-4), 121-145. http://dx.doi.org/10.1016/0378-3839(96)00014-2
Wang, P., Smith, E. R., and Ebersole, B. A. 2002. Large-scale laboratory measurements of longshore sediment transport under spilling andplunging breakers. Journal of Coastal Research, 18(1), 118-135.