Park. H.-B. and Vincent, C. E., 2007. Evolution of Scroby Sands in the East Anglian coast, UK. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 868 – 873. Gold Coast, Australia, ISSN 0749.0208

Scroby Sands, a major nearshore sandbank on the East Anglian coast of the U.K., is constantly changing its configuration and alignment with the surrounding sandbanks. Analysis of sixteen charts between 1846 and 1992 shows that the area of shallowest part of Scroby (above the -5 m depth contour) has steadily increased over this period with significant movements in the north-south direction by either accumulating or redistributing sand. Numerical modelling using the TELEMAC finite element system was used to investigate the importance of hydrodynamic conditions in modifying this sandbank by simulating waves, tidal currents and sand transport over this complex region, and to suggest the future long-term morphological evolution of Scroby Sands. Waves around, and inshore of, Scroby are strongly influenced by the water depth over this sandbank; North Scroby, which is a relatively low part of Scroby, allows offshore waves to penetrate to the shore with strong refraction and energy dissipation due to the bottom friction and depth-induced breaking, while South Scroby, the highest part of Scroby, protects the shore by providing direct shelter. The spatial distribution of residual tidal currents demonstrates that the local flood-ebb asymmetry is strongly influenced by the local water depth. The sand transport/morphodynamic model suggests that Scroby evolves slowly under the action of tidal currents alone, but migration is significantly accelerated under the combined wave-tidal current action, especially with northerly storms. The bed evolution, under a variety of hydrodynamic conditions, implies that shallower part of Scroby (less than 10 m water depth) will gradually migrate to the N-NE, joining with Caister Shoal and Caister Ness through Cockle Shoal, while Caister Shoal and North Cross Sand will move to the N-NW.