AN ECOSYSTEM SERVICES BASED MODEL FOR THE RECLASSIFICATION OF URBAN USES IN PLANS: A DECISION SUPPORT FOR THE MINIMISATION OF SOIL CONSUMPTION

A DECISION SUPPORT FOR THE MINIMISATION OF SOIL CONSUMPTION

Abstract

Soil that is not artificially covered is capable of providing services with both direct and indirect benefits for humans. It is, therefore, essential to assess the impacts of different land-use and urban planning choices by estimating costs and benefits associated with different land-use scenarios and/or protection policies. 

The dimensioning of municipal urban plans (Puc) sets the urban load, in accordance with the regulations, with the provisions contained in the Provincial Territorial Coordination Plans (PTCP) and on the basis of a careful analysis of the community's actual and irrepressible needs. 

The possible transformations envisaged in the Pucs lead to two types of consequences: on the one hand, they constitute a potential income for the municipal coffers in terms of taxation on building land and buildings constructed and in terms of urbanisation charges; on the other hand, the transformation of the land entails the definitive loss of the numerous and very valuable Ecosystem Services (ES) that it is able to provide. 

These are defined by the Millennium Ecosystem Assessment (MA, 2005) as the multiple benefits provided by ecosystems to humankind and are divided into four categories: life support, provisioning, regulation and cultural values. A variety of approaches to assessing the ES provided by different land covers can be found in the literature. Some of them are based on matrices that, based on the opinion of experts (such as physical geographers, forest scientists and environmental engineers), associate each land cover class with a score related to the level of performance offered by each ES (Costanza et al., 1997; De Groot, 2010; Burkhard et al., 2012; Rodriguez, Armenteras & Retana, 2015; Santolini et a., 2015). 

The change in land cover from its natural state to artificial cover is technically termed land consumption. Forms of consumption range from total loss of the soil resource to partial loss of ES functionality. urban densification is also a form of land consumption insofar as it involves the introduction of new artificial cover in urban areas (Munafò, 2021). Zeroing net soil consumption means, therefore, avoiding the sealing of agricultural and open areas and, for the residual component that cannot be avoided, compensating it by renaturalising an area of equal or greater extent in order to restore its capacity to provide ES (EC, 2016). When considering soil as a resource, it is necessary to distinguish between land cover and land use. The term land cover refers to the biophysical cover of the earth's surface, while land use refers to the actual biophysical state of the soil, related to its use in human activities. The latter is, therefore, defined according to the present and planned functional dimension and urban use (Directive 2007/2/CE). A change of land use (and even less a change of land use provided for by a town planning instrument) may not alter the functions of the land and its capacity to provide SE and, therefore, not represent real land consumption. «The relationship between land consumption and population dynamics confirms that the link between demography and urbanisation and infrastructural processes is not direct and there is a growth of artificial surfaces even in the presence of stabilisation, in many cases decrease, of residents» (Munafò, 2021: 45). From this, the importance of correctly sizing Pucs, carefully balancing the need for new areas for human activities with the preservation of ES, aiming to achieve settlement efficiency (Fasolino, Coppola & Grimaldi, 2020).