Land degradation in Mediterranean urban areas: an unexplored link with planning?

Abstract

This paper examines the role of biophysical and anthropogenic factors as potential drivers of land degradation in a large Mediterranean urban region. The sensitivity of land to degradation is examined in relation to the territorial disparities observed within Rome's metropolitan area (Italy), and to the changes in its spatial organisation resulting from urban shrinkage. We derive a composite index of land sensitivity to degradation using the Environmentally Sensitive Areas Index (ESAI) at the municipal level. The observed regional disparities in ESAI scores are analysed diachronically for the period 1990–2008, based on elevation, distance from the coast and population density. The results indicate that spatial disparities in ESAI recorded in 1990 had decreased by 2008, although the degree of land sensitivity had increased throughout the urban region. We subsequently relate these changes to different models of urban organisation (i.e. ‘compact growth’ vs ‘sprawl’) observed in Rome since the 1990s. In 1990, the highest degree of land sensitivity was on the urban fringe of Rome, whereas by 2008 the greatest increase in land sensitivity was observed within suburban municipalities. This sensitivity progressively spread further away from the main urban centre during the study period. The results suggest the need to reconsider the polycentric spatial framework as an environmentally sustainable model for Rome and other urban regions in the Mediterranean.