Estimating soil sealing rate at national level—Italy as a case study

Soil sealing has been regarded as a key environmental problem since sealed soils lose several of their functions determining a reduction in land productivity and quality. Unfortunately, the analysis of changes in land-use carried out through the use of traditional data sources allows a relatively rough estimation of this phenomenon. The aim of this paper is to illustrate a procedure quantifying over time the soil sealing rate at the country scale. Italy was chosen as the study area due to its spatially-complex urbanization patterns. The procedure was based on the visual interpretation of aerial photographs and high-resolution topographic maps taken at four points in time (1956, 1994, 1999, 2006) in a random sample of field plots homogeneously distributed across the country. Results indicate that soil sealing continuously increased in Italy over the investigated period with the highest absolute and per-capita growth rate of sealed areas being observed respectively in northern and southern Italy. Compared to past, per-capita soil sealing was higher in the most recent period (1999–2006).