Modelling future landscape change on coastal floodplains using a rule-based GIS

A large-scale, strategic-level method has been developed to facilitate dialogue with policymakers on future coastal land-use management, in the context of climate change and the implications of sea-level rise for floodplain areas. Impacts from different management policies are explored through their influence on patterns of flooding and consequent landscape change. The method is based upon a series of transition rules linking frequency of inundation by the sea to changes in land use and land cover at key threshold values. A high-resolution digital elevation model derived from Interferometric Synthetic Aperture Radar (IfSAR) provides the topographic information required for relating sea-level rise to tidal and flood frequency limits. The rule-based approach allows a rapid evaluation of multiple policy options and critical assumptions can be made more transparent and responsive to end-users than with conventional modelling approaches. A case study example is provided from the North Norfolk coast in eastern England, where the results imply that future sea-level rise has much broader policy implications for the human and ecological landscape than just flood risk to property.