PREDICTING OVERWASHING AND BREACHING OF COARSE-CLASTIC BARRIER BEACHES AND SPITS – APPLICATION TO MEDMERRY, WEST SUSSEX, SOUTHERN ENGLAND

摘要

The majority of barrier beaches and spits along the south coast of England are in the ultimate phase of barrier breakdown (Carter and Orford, 1984). This is due to an imbalance between their forcing hydrodynamic and resisting morphodynamic factors. The Holocene sediment supply that once fed these dynamic systems is no longer readily available because of natural and anthropogenic causes. Management in the form of “hard” and “soft” engineering is required therefore, to maintain stability as flood defences in their present positions. Current management practices are often not economically viable or sustainable solutions in the long term. With greater risks predicted, arising from sea level rise and increased storm surges, significant management decisions must be made with a limited understanding of the way that these beaches perform under storm attack. Findings from application of Bradbury’s (1998) overwashing model at the Medmerry barrier, West Sussex are presented.