SHORELINE ADJUSTMENTS AND COASTAL MANAGEMENT - PHYSICAL AND BIOLOGICAL PROCESSES UNDER ACCELERATED SEA-LEVEL RISE

The physical responses to predicted sea-level rise are examined using examples from the south-east coast of Britain where tectonically induced sea level rise are already equivalent to those predicted under the global warming hypothesis. Intertidal profiles on this coast are shifting both upwards and shorewards while estuarine channels are becoming wider and shallower. These natural changes are interrupted by the presence of flood embankments which can force tidal waves inland along the estuary setting up increased flood risks here. Biological communities such as salt marsh are also affected and appear to be migrating inland along the estuary in response to sea-level changes but again this process is interrupted by flood embankments. Managed retreat of the embankments may alleviate some of these problems but this should not take the form of semi-enclosed tidal cells formed by breaching the present defences. Instead the increases in tidal prism and the effects of this on estuarine hydro-dynamics should be considered and an holistic management plan prepared for each coastal and estuarine area.