The spatial pattern of soil sealing along the urban-rural gradient in a Mediterranean region

This paper explores the spatial distribution of soil sealing in a compact and mono-centric urban region of southern Europe through multivariate statistics and spatial analysis. The study demonstrates how simple indicators developed at the local scale can provide insight in the analysis of urbanisation-driven soil sealing. Based on a high-resolution land-use map, a 'sealing profile' was determined for each municipality of the Athens' urban region, by analysing the distribution of land occupied by 22 classes of imperviousness using a Principal Components Analysis. Four indicators of soil sealing have been developed (percentage of pervious land, per capita sealed land, soil sealing intensity and diversity in soil sealing intensity) and the investigated municipalities classified accordingly. All indicators were found correlated to the distance from the city centre of Athens. Three groups of municipalities (strictly urban, suburban and rural municipalities) have been identified based on the four sealing indicators and the distance from the inner city. Results suggest that the spatial distribution of soil sealing in Athens reflects the transition from a mono-centric and compact urban form to a polycentric and dispersed agglomeration, with implications for urban containment policies.