Numerical modelling of equilibrium and evolving lightweight sediment laboratory beach profiles.

Type Proceedings paper
Date 2013
Language English
Other localization
Author(s) Dubarbier Benjamin1, Castelle Bruno1, Marieu Vincent1, Michallet Hervé2, Grasso FlorentORCID3, Ruessink Gerben4
Affiliation(s) 1 : UMR EPOC, University of Bordeaux, Avenue des Facultés, Talence 33405, France
2 : Laboratoire des Ecoulements Géophysiques et Industriels, CNRS, BP 53, 38041 Grenoble cedex 9, France.
3 : IFREMER, Laboratoire de physique hydrodynamique et sédimentaire DYNECO/PHYSED Centre de Bretagne, BP 70, 29280 Plouzané, France
4 : Faculty of Geosciences, Utrecht University, Utrecht, 3508 TC, The Netherlands
Meeting Coastal Dynamics 2013 - 7th International Conference on Coastal Dynamics, 24-28 June 2013, Arcachon, France
Source Proceedings on Coastal Dynamics 2013, pp.521-530
Keyword(s) Beach profile, numerical model, physical modelling, equilibrium profile, sandbar migration
Abstract The recent advances of numerical beach profile models allowed the simulation of on/offshore sandbar migrations on timescales of weeks to months with fair success. These models were systematically applied to natural, persistently evolving, beaches. In this contribution, we apply our model to small-scale laboratory experiments for which coarse and lightweight sediment is used to satisfy the laws of similitude in the flume. Such experiments can result in equilibrium beach profiles and provide detailed information on the respective role of undertow and wave nonlinearities on sediment transport and the resulting cross-shore sandbar migration. Here we first apply the coupled, wave-averaged, cross-shore waves-currents-bathymetric evolution model 1DBeach to an equilibrium beach profile. The model simulates an equilibrium beach profile with reasonable success. Yet, when applying the best fit parameters to a subsequent rapid onshore sandbar migration, the model fails in reproducing the overall beach profile evolution. Further model calibration on the evolving beach profile sequence shows that the model can actually reproduce the rapid onshore sandbar migration with a significant contribution of acceleration skewness. This suggests that a number of misspecifications of the physics remain in coupled, wave-averaged, cross-shore waves-currents-bathymetric evolution model. In addition, given that best-fit model free parameters are of the same order of magnitude of those found on natural beaches, our study suggests that small-scale experiments with coarse and lightweight sediment can be used to further explore the respective contribution of wave nonlinearities and undertow to sediment transport and the overall beach profile evolution
Full Text
File Pages Size Access
Publisher's official version 10 2 MB Open access
Top of the page

How to cite 

Dubarbier Benjamin, Castelle Bruno, Marieu Vincent, Michallet Hervé, Grasso Florent, Ruessink Gerben (2013). Numerical modelling of equilibrium and evolving lightweight sediment laboratory beach profiles. Proceedings on Coastal Dynamics 2013, pp.521-530.