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Sediment Movement

Patterns off the East Kent Coastline

The construction of Dover Harbour appears to have created a self-contained unit between Dover and Sandwich Bay. Very little beach material passes eastwards across Dover Harbour and none leaves Sandwich Bay. From Dover round South Foreland to St. Margaret's Bay the coastline faces Southeast and the south-westerly winds cause a northerly drift of material.

Beach Accretion at Walmer Castle

 walmer castle and coast birds eye view in 1948

 walmer castle and coastline aerial view in 1999

As the coastline turns this gradually dies out so in the area by Walmer Castle the rate of drift is much reduced. From there northwards there is a gradual increase of residual drift in the opposite direction, so that from Sandown Castle to Deal Castle there is an indication of a strong residual drift to the south although the predominant drift remains northwards from Sandown Castle to a point opposite Sandwich. This effect rapidly dies out until there is again an area in the Bay of no residual drift at all.

Although the rate of drift follows a pattern this can increase during, for example, severe south-easterly storms and this may explain why there has been a gradual extension northwards of the limit reached by the shingle.

By 1960 it became clear that the amount of shingle arriving at Kingsdown was less than the amount leaving towards Walmer. The sea walls and groynes have been developed since that time to prevent further erosion of the frontage.

Today much attention is being paid to the 6-kilometre coastline between Deal and Kingsdown. Recent studies estimate that the beach frontage suffers a net annual loss of 18,000 m3 per year, posing a great risk to the settlement areas of Deal and Kingsdown to erosion and flooding. There is no doubt that the beach will require continued maintenance in order to maintain the required standard of protection.


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