How to measure the sustainability of an area: the SPIn-Eco project of the province of Siena

The SPIn-Eco project has been proposed and funded with the aim of studying the Province of Siena (Italy) and the 36 municipalities into which it is divided from the viewpoint of sustainable development. Several sustainability indicators are used to point out the weak and the strong points for the territory with respect to sustainability. In this paper we have focused our attention on the following methodologies: emergy evaluation, ecological footprint, greenhouse gases balance. The sustainability analysis made during the SPIn-Eco, project has produced a data set that allows a practical comparison among these approaches by means of a correlation analysis. The correlations among several indicators based on the above data set are shown. The aim of this paper is to underline the similarities and differences among the three methodologies through correlation analysis. Important correlations were found between ecological footprint and CO2 emissions as well as with the non-renewable exogenous part of emergy flow. No correlation was found between total emergy flow and total ecological footprint.