Characterization of non-urbanized areas for land-use planning of agricultural and green infrastructure in urban contexts

Non-urbanized areas (NUAs) are outdoor places with significant amounts of vegetation. They are mainly semi-natural patches that represent the last remnants of nature in metropolitan areas. As part of the agricultural and green infrastructure they provide ecosystem services, such as purification of air and water, mitigation of floods and droughts, re-generation of soil fertility, moderation of temperature extremes and enhancing of landscape quality. Like all natural ecosystems, NUAs today are endangered by urban sprawl, which is the main cause of their fragmentation and loss of evapotranspiration features. For these reasons, the protection of these areas is a fundamental issue for land-use planning, and it requires appropriate strategies for their management. We propose a land-use suitability strategy, based on five different analytical phases, to address the land-use of NUAs: (1) land-use and land cover analysis quantifies the percentage of evapotranspiring surface for each land-use; (2) fragmentation analysis assesses the size and density of NUAs; (3) proximity analysis takes into account the degree to which NUAs are close to residential areas; (4) the results from these analyses are integrated in a land-use suitability matrix, which produces as output a new scenario of prospective land-uses for NUAs; (5) a compatibility matrix verifies the correspondence of these new land-uses with the current ones to confirm or modify the proposed land-uses. The resulting scenario allows to enhance the production of ecosystem services and define new appropriate land-uses for NUAs within the agricultural and green infrastructure. The method is tested on three municipalities within the Catania metropolitan area (Italy), characterized by a considerable urban sprawl.