You are here:
Emergy evaluation of hierarchically nested systems: application to EU27, Italy and Tuscany and consequences for the meaning of emergy indicators
Citation:
Morandi, F., Daniel E. Campbell, F. Pulselli, AND S. Bastianoni. Emergy evaluation of hierarchically nested systems: application to EU27, Italy and Tuscany and consequences for the meaning of emergy indicators. ECOLOGICAL MODELLING. Elsevier Science BV, Amsterdam, Netherlands, 315:12-27, (2015).
Impact/Purpose:
This paper is the third in a series resulting from the 9 months that Fabiana Morandi spent at NHEERL’s Atlantic Ecology Division as a visiting scientist. During this time she developed an elegant mathematical method based on set theory for analyzing complex territorial systems that have nested hierarchical structures. The first two papers developed the mathematical basis for quantifying the forcing functions and the multi-scalar interactions within such systems. This paper presents a case study analysis for illustrating the use of the method in the analysis of the multi-scalar, nested system comprised of the EU27-Italy, and Tuscany. The results demonstrated that the set of imported flows changes its cardinality with a change in scale and consequently the values of emergy indices such as the Environmental Loading Ratio (ELR), the Emergy Investment Ratio (EIR) and the Emergy Yield Ratio (EYR) are different among scales. Overall impact of these three papers may be large considering that they put forward a mathematical method to ensure that double counting will be absent from complex multi-scalar territorial analyses using emergy evaluations. The methods developed are completely general and can be applied in other assessment methods addressing similar multi-scalar systems.
Description:
What is the role of a system's size in an emergy evaluation, when we have to evaluate nested systems? To answer this question, we consider a simple nested system with three levels of organization and then examine the relationships among the emergy flows at each level and among the indicators derived from these flows. As an example of nested systems with three levels of organization, we consider a nested territorial system that is European Union–Italy–Tuscany. In particular, this system is analyzed as Italy within the European Union and Tuscany within Italy. The emergy evaluation of each hierarchical pair of system levels is presented using a new method based on set theory and, moreover, each level is analyzed as an independent system. This “double analysis” is necessary because the emergy indicators obtained for each level, are analyzed and compared to show the differences that appear when the system under study is considered as part of the larger system that contains it. In this work, data analysis shows that the set of imported flows changes its cardinality when changing the level in the hierarchically organization. In particular, with respect to EU27 and Italy, it emerges that Tuscany has a very high Environmental Loading Ratio (ELR), while EU27 has the lower value both for the Emergy Investment Ratio (EIR) and for the Emergy Yeld Ratio (EYR). It means that in Tuscany there is a big pressure on ecosystems from non-renewable flows while, in general, the EU27 might be a good place for future economic investments.
