The couple rapid urbanization and policy failure in controlling urban expansion was sometimes associated to soil and land degradation phenomena in both developing and developed countries. This work points to investigate the link between exurban development and soil/land degradation in the region of Athens (Greece) as a typical semiarid Mediterranean area experiencing a shift from a land-saving compact urban form to a dispersed, low-density urban expansion. The examined area is among the most populated areas in the Mediterranean basin showing an enormous population growth during the last 60 years. While low-density, dispersed urban settlements mainly developed over the decade (2000–2010) in the investigated area occupied mostly land classified at poor soil quality, the overall assessment of vegetation, climate and soil quality layers renders a complex picture in which exurban development consumed high-quality land that were classified as non-vulnerable to land degradation. On the contrary, compact urban settlements prevail in land with intermediate (or even high) soil quality but with inadequate climatic and vegetation conditions, which are classified as highly vulnerable to land degradation. Urban planning should integrate multi-dimensional indicators of soil, climate and vegetation quality to evaluate the environmental impact of exurban development.

The development of low-cost and relatively simple tools to identify emerging land degradation across complex regions is fundamental to plan monitoring and intervention strategies. We propose a procedure that integrates multi-spectral satellite observations and air temperature data to detect areas where the current status of local vegetation and climate shows evident departures from the mean conditions of the investigated region. Our procedure was tested in Basilicata (Italy), which is a typical bio-geographic example of vulnerable Mediterranean landscape. We grouped Landsat TM/ETM+ NDVI and air temperature (T) data by vegetation cover type to estimate the statistical distributions of the departures of NDVI and T from the respective land cover class means. The pixels characterized by contextual left tail NDVI values and right tail T values that persisted in time (2002–2006) were classified as critical to land degradation. According to our results, most of the critical areas (88.6%) corresponded to forests affected by erosion and to riparian buffers that are shaped by fragmentation, as confirmed by aerial and in-situ surveys. Our procedure enables cost-effective screenings of complex areas able to identify raising hotspots that require urgent and deeper investigations.