Sand waves characteristics: theoretical predictions versus field data.

Sand wave characteristics are predicted using the three-dimensional model proposed by Blondeaux and vittori (2005a), Blondeaux and vittori (2005b) and later developed by Besio et al. (2006). Turbulence generated by tidal currents is described by introducing an eddy viscosity which is assumed to depend on the distance from the bottom. Moreover, sediment is supposed to move both as bed load and suspended load since, at some locations, field surveys show that large amounts of sediment are put into suspension and transported by the tidal currents. The predictive capability of the model of Besio et al. (2006) is tested by comparing theoretical predictions with a large field data set. In particular the field observations carried out along the continental shelf of Belgium are used. The field data are described in Mouchet (1990) andVan Lancker et al. (2005) . The theoretical predictions are found to fairly agree with field observations, even though some of the comparisons suggest that the accuracy of the predictions depends on the accurate evaluation of the local current and sediment characteristics.