An idealised study for the long term evolution of crescentic bars

Chen, W.L.; Dodd, N.; Tiessen, M.C.H.; Calvete, D.

Abstract

An idealised study that identifies the mechanisms in the long term evolution of crescentic bar systems in nature is presented. Growth to finite amplitude (i.e., equilibration, sometimes referred to as saturation) and higher harmonic interaction are hypothesised to be the leading nonlinear effects in long-term evolution of these systems. These nonlinear effects are added to a linear stability model and used to predict crescentic bar development along a beach in Duck, North Carolina (USA) over a 2-month period. The equilibration prolongs the development of bed patterns, thus allowing the long term evolution. Higher harmonic interaction enables the amplitude to be transferred from longer to shorter lengthscales, which leads to the dominance of shorter lengthscales in latter post-storm stages, as observed at Duck. The comparison with observations indicates the importance of higher harmonic interaction in the development of nearshore crescentic bar systems in nature. Additionally, it is concluded that these nonlinear effects should be included in models simulating the development of different bed patterns, and that this points a way forward for long-term morphodynamical modelling in general.

Citation

Chen, W., Dodd, N., Tiessen, M., & Calvete, D. (in press). An idealised study for the long term evolution of crescentic bars. Continental Shelf Research, https://doi.org/10.1016/j.csr.2017.11.006

• Journal Article Type: Article
• Acceptance Date: Nov 19, 2017
• Online Publication Date: Nov 22, 2017
• Deposit Date: Nov 30, 2017
• Publicly Available Date: Nov 23, 2018
• Journal: Continental Shelf Research
• Print ISSN: 0278-4343
• Electronic ISSN: 1873-6955
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1016/j.csr.2017.11.006
• Public URL: https://nottingham-repository.worktribe.com/output/896214
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0278434317302200
• Contract Date: Nov 30, 2017