Urbanisation and Land Take of High Quality Agricultural Soils - Exploring Long-term Land Use Changes and Land Capability in Northern Italy

Document Type: Original Research Paper

Authors

1 Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Unit for Climatology and Meteorology applied to Agriculture (CRA-CMA), Via del Caravita 7a, I-00186 Rome, Italy

2 Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centre for the Study of Plant-Soil Interactions (CRA-RPS), Via della Navicella 2-4, I-00184 Rome, Italy

Abstract

Urban expansion and agriculture intensification are relevant drivers in Land Degradation (LD)
processes in Europe due to net loss of land, soil sealing, landscape fragmentation and other negative effects on the environment. This paper explores changes (or “trajectories” of change) in land use and cover (LULC) and their relationship with the consumption of soils in Emilia-Romagna (northern Italy) over a 55-years period from 1954 to 2008, and separately over three time periods (1954-1976, 1976-1994 and 1994-2008) characterized by distinctive processes of urban and agricultural development. Four high-resolution LULC maps for 1954, 1976, 1994, and 2008 were analysed together with a 1:50,000 scale land capability map used as an indicator of soil quality. Out of an investigated area of around 12.000 km2, 34% underwent changes in LULC over the entire study period. “Agriculture internal conversions” accounted for 46% of the changes and “urban expansion” for as much as 35%. The first period was characterized by “agriculture internal conversions” associated with intensification processes. In the second period internal agricultural conversions became even more important. In the third period the most relevant conversion process was agricultural extensivation, with urban expansion also becoming relevant. During the entire period, the area consumed by urban expansion took around 41 % of the high-quality soils. Other trajectories consumed soils of lower quality, with the exception of internal agricultural conversions (accounting for another 46%). The suggested approach can provide valuable indications for assessing quantity and quality of soils taken by urban expansion, thus orienting sustainable land management.

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