Coastal areas are economically vital in terms of population, industry, trade and tourism. The numbers of people and properties at risk will increase as economies grow or develop, while climate change will amplify the likelihood of extreme events, as well as accelerate potential habitat decline. The development of a systematic approach to deliver both a low-risk coast for human use and healthy habitats subject to multiple change factors is envisaged within the European project THESEUS of which this study forms a part. Plymouth Sound to Exe Estuary (UK) is one of several project sites. This site involves complex coastal and estuarine processes; interactions between coastal defence structures, coastal morphology and ecological habitats; and significant economic, social and environmental impacts, which makes a really interesting and challenging site to study. The source-pathway-receptor-consequence or ‘S-P-R-C’ methodology was adopted to identify the risk of flooding and erosion. This method is a simple conceptual model for representing systems and processes that lead to a particular consequence. Sources, pathways and receptors have been identified and defined in a GIS system, the information for the sources was derived from tide gauges at Plymouth and Exmouth, simulated surge and wave conditions derived from running POLCOMS (over 4 x 30 year time slices) for present conditions and the A1B scenario (short-, mid- and long-term). Pathway information was obtained from a variety of sources but largely from the UK Environment Agency databases. Receptors were defined on the basis of land use obtained from the CORINE database from the European Environment Agency, terrain elevation data and defence type. It is concluded that should the extreme changes for the four main sources (mean sea-level, waves surge and river flow) coincide, the impact would be catastrophic if land usage remains as it is today. |
