A Multicriteria Spatial Decision Support System Development for Siting a Landfill in the Province of Torino (Italy)

The present paper proposes a spatial multicriteria approach for supporting Decision-Makers in the siting process of a Municipal Solid Waste landfill in the Province of Torino (Italy). In particular, the contribution illustrates the development of a Multicriteria-Spatial Decision Support System based on the integration of Geographic Information Systems and a specific Multicriteria Decision Analysis technique, named Analytic Network Process (ANP). This technique, which represents the generalization of the more well-known Analytic Hierarchy Process to dependences and feedbacks, is particularly suitable for dealing with complex decision problems which are characterized by inter-relationships among the elements at stake. The application allows the dependence relationships among the criteria to be assessed, and the relative importance of all the elements that play an influence on the final choice to be evaluated. The purpose of the study is to generate a suitability map of the area under analysis for locating a waste landfill, paying particular attention to the contribution that the spatial ANP offers to sustainability assessments of undesirable facilities. To this end, the simple network structure has been used and both exclusionary and non-exclusionary criteria have been identified and grouped into clusters. The results are obtained in the form of suitability maps analysed through ilwis 3.3 software (52North, ITC, Enschede, The Netherlands) and have been further verified through a sensitivity analysis with reference to the clusters priorities in order to test the robustness of the proposed model. The main findings of this research have proved that the spatial ANP is a useful tool to help technicians to make their decision process traceable and reliable. Moreover, this approach helps Decision-Makers to undertake a sound reflection of the siting problem. Finally, the implementation of the spatial ANP technique gives an originality value to the present research because it represents one of the first applications at both the national and international level.