Eco-dynamics of territorial systems: an Emergy Evaluation through time

摘要

Environmental sustainability requires ongoing care from the public administration to improve people's quality of life, without jeopardizing the natural resources upon which human activities are founded. The aim of this paper is to present an environmental sustainability assessment of a local territorial system based on a thermodynamic method: Emergy Evaluation. Emergy Evaluation is able to compare the value of human and natural systems on a common basis: the quantity of solar energy directly and indirectly required for a process that represents the memory of all the energy and matter that the biosphere used up to make a product available or to support a territorial system. The use of Emergy enables the calculation of some indicators (such as Environmental Loading Ratio, Emergy Yield Ratio, Emergy Density, Emergy Investment Ratio), in order to give a systemic and holistic picture of the territorial system from a sustainability point of view. By Emergy approach it was possible to distinguish if the territory plays the role of transformer of raw materials or a final consumer of refined materials. The paper proposes and compares two scenarios realized in different years (1997 and 2003), in order to monitor and overview the evolution of a local system. The territorial system analyzed is the Province of Modena which is located in the north of Italy and is characterized by dynamic productive sectors, such as food, steel and ceramic industries, and an important population density (242 inhabitans/km~2). Results show an increasing trend of all emergy flows and indicators quite typical for an industrialized country. This is especially due to the higher request for goods and services from outside the boundaries of the system. Nevertheless, the total renewable flow is increased to 7.3% thanks to a higher use of energy from renewable sources, i.e. hydro and co-generation. This is due to the attention that the Administration has devoted in the last ten years.