KM-SCALE SHORELINE SAND WAVES: NUMERICAL MODELLING AND OBSERVATIONS

Jaime Arriaga, Francesca Ribas, Ismael Mariño-Tapia, Albert Falqués

Abstract


Km-scale shoreline sand waves have been studied with a quasi two dimensional model (Q2D-morfo model) and with observations from a populated coastal zone in Yucatán (México) with frequent human interventions. The model was modified to improve the physics in the case of large amplitude shoreline sand waves that develop due to the high angle wave instability (HAWI). The modified version of the model can better reproduce the formation of large-amplitude shoreline sand waves, compared with the original model. Shorelines of Yucatán, from 2004 to 2012, were digitized and analyzed. Although undulations can be observed, they do not exhibit clear migration or growth, an indication of being in the limit of instability, in accordance with the results of the model.

Keywords


Shoreline sand waves; High angle wave instability; Yucatán coast

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References


A. Ashton, A. B. Murray, and O. Arnault. Formation of coastline features by large-scale instabilities induced by high-angle waves. Nature, 414:296–300, 2001.

P. Bruun. Migrating sand waves or sand humps, with special reference to investigations carried out on the Danish North Sea Coast. In Coastal Eng. 1954, pages 269–295. Am. Soc. of Civ. Eng., 1954.

G. Coco and A. B. Murray. Patterns in the sand: From forcing templates to self-organization. Geomorphol- ogy, 91(271-290), 2007.

A. Falqués and D. Calvete. Large scale dynamics of sandy coastlines. Diffusivity and instability. J. Geophys. Res., 110(C03007), 2005. doi:10.1029/2004JC002587.

D. Idier and A. Falqués. How kilometric sandy shoreline undulations correlate with wave and morphology characteristics: preliminary analysis on the atlantic coast of africa. Advances in Geosciences, 39:55–60, 2014. doi:10.5194/adgeo-39-55-2014.

K. Kaergaard and J. Fredsoe. Numerical modeling of shoreline undulations part 1: Constant wave climate. Coastal Eng., 75:64–76, 2013.

K. Kaergaard, J. Fredsoe, and S. B. Knudsen. Coastline undulations on the West Coast of Denmark: Offshore extent, relation to breaker bars and transported sediment volume. Coastal Eng., 60:109–122, 2012.

P. D. Komar. Beach Processes and Sedimentation. Prentice Hall, Englewood Cliffs, N.J., second edition, 1998.

R. Pelnard-Considère. Essai de theorie de l’evolution des formes de rivage en plages de sable et de galets. In 4th Journees de l’Hydraulique, Les Energies de la Mer, Paris, volume III(1), pages 289–298. Société Hydrotechnique de France, 1956.

F. Ribas, H. E. de Swart, D. Calvete, and A. Falqués. Modeling and analyzing observed transverse sand bars in the surf zone. J. Geophys. Res., 117(F02013), 2012. doi:10.1029/2011JF002158.

N. van den Berg, A. Falqués, and F. Ribas. Modelling large scale shoreline sand waves under oblique wave incidence. J. Geophys. Res., 117(F03019), 2012. doi:10.1029/2011JF002177.




DOI: https://doi.org/10.9753/icce.v34.sediment.68