A New Environmental Indicator for Coastal Artificialisation and Resilience Mapping

ABSTRACT T EJADA , M., M ALVAREZ , G.C. and N AVAS , F., 2007. A New Environmental Indicator for Coastal Artificialisation and Resilience Mapping. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 67 – 71. Gold Coast, Australia, ISSN 0749.0208 Scientists and managers have developed and improved coastal protection and sustainable development measures. However, analysis and diagnostic methods are less than satisfactory when coping with the true complexity of socio economic drivers in coastal areas. Mapping of land use and its temporal variability in the coastal lands enables a first order approximation to the analysis of artificialisation although it shows a snap shot of the situation. An indicator which compares the evolution of land uses over a significant time span in the evolution of a developed coast as well as its spatial behaviour is introduced in this paper. The method, applied on the highly developed coastlines of Torremolinos in Costa del Sol, southern Spain, involves (i) mapping of a series of photo interpreted land use coverage stretching over 40 years; (ii) the implementation of a new algorithm that identifies land use change and calculates distance of change in relation to shoreline across a 1 km. buffer fringe; and (iii) transposing land use variability by qualifying via the concept of resilience onto the mapped shoreline to enable cartographic output of the analysis. Results of the implementation of the method on the selected pilot site and timeframe illustrate a high capability to interpret resilience (beyond sole scientist’s perception). The process of artificialisation is quantified and represented on a map which helps locating areas of potential high and low resilience (as in capacity to recover) given the trends. This is illustrated by mapped results and a final resilience map that could be of use for future decision making in the context of coastal management of developed coasts.