Daly C. J. auteur aut IRD Floc'h F. auteur aut IRD Almeida L. P. M. auteur aut IRD Almar Rafaël auteur aut IRD Jaud M. auteur aut IRD text journalArticle eng text/pdf born digital access A field of beach cusps formed during a field experiment at Nha Trang Beach, Vietnam, under accretive conditions. The measured data was used to set-up morphodynamic simulations in XBeach, which was able to simulate cusp formation from an initially long-shore uniform beach profile. Several types of simulations were run in order to observe the resulting variation in mean cusp dimensions (length, depth and height), swash flow patterns, and sediment sorting. Both time-constant (JONSWAP) and time-varying (measured) wave forcing conditions were superimposed on the measured tide. In the former, four wave parameters were varied (wave height, period, direction, and spreading), while in the latter, the median sediment size and sediment composition were varied. The wave period was found to primarily influence long-shore length scales, the wave height cross-shore length scales, and obliquely incident waves enhance all these dimensions particularly under narrow-banded conditions. Cusps are not prominent if the wave energy is too low to effect significant onshore transport, if the wave angle of incidence and spreading are too large (effectively smoothing out swash perturbations), or if the sediment is too fine in relation to the wave conditions (dissipative beaches or highly erosive wave conditions). Coarse sediment generally tends to be located on cusp horns above the waterline, but is otherwise variable depending on cross shore location and tide levels. As the XBeach model results show large agreement with well-established norms, it may therefore be used to more rigorously study processes that help to initiate cusps in future work. specialized Beach cusps Onshore sediment transport Pattern formation Wave forcing Sediment sorting VIET NAM NHA TRANG 064 032 020 389 107798 [13 p.] 2021 0169-555X https://www.documentation.ird.fr/hor/fdi:010082689 10.1016/j.geomorph.2021.107798 0169-555X [F B010082689] https://www.documentation.ird.fr/hor/fdi:010082689 https://www.documentation.ird.fr/intranet/publi/2021-09/010082689.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-09-17 2025-02-24 fdi:010082689 fre