Emergy Evaluation of Regions and Sub-Regions: Application to Portugal

Emergy evaluation is an important tool to understand, quantify and characterize the flows that give support to all sort of systems, including urban areas and countries. It has the ability to account all forms of energy, resources and human services, by converting them to a same quantity, emergy, whose unit is the solar emergy joule (seJ). The methodology of analysis allows obtaining emergy indices that establish several relationships between environmental and economic flows of a system, can evaluate its sustainability, and so facilitate decision making. This work does an emergy evaluation of a country, Portugal, one of its subregions, Vale do Ave, and a municipality of the latter, Vila Nova de Famalicão. The emergy indices obtained for each of these three levels of organization were analysed and compared with each other and with those of other studies. The three systems present a very low Environmental Sustainability Index (ESI), Famalicão having the lowest, meaning short term sustainability for the three regions. Portugal has the highest Emergy to Money Ratio (EMR), which means a lower development and more disadvantage in trade, when compared with the regions of Vale do Ave and Vila Nova de Famalicão. The evaluated emergy indices also show that all three regions are highly depend of external resources.