Efficienza economica e conservazione dei sistemi naturali nell'allocazione della risorsa suolo tra usi alternativi: un modello multicriteriale di aiuto alle decisioni nella pianificazione territoriale sostenibile

The thesis focuses on valuation in land use allocation, dealing with the problem of determining the optimal choice among alternatives in land planning. The aim of the thesis is double. In fact, on the one hand, the role of valuation in planning activities is investigated, in the light of sustainable development concept; on the other and, an original decision aiding methodology is proposed, which can be used by planners to select an optimal land use plan that balances the socioeconomic benefits and environmental impacts. The thesis is divided in two parts: the first part focuses on sustainability and planning concepts, deepening the role of valuation in sustainability assessment of land use plans; the second part shows the methodology proposed. The first part is made up by three chapters. The first chapter enters the concepts of sustainability and natural capital, and the debate on economic growth (expansionistic versus ecological paradigm). In the second chapter, the relationship between valuation and planning process, its development in the course of time, and the development of new valuation methods for sustainability assessment in planning are investigated. The most diffused approaches are illustrated: the cost-benefit approach, the multi-criteria evaluation, and the new "landscape approach". In the third chapter, methods for natural capital assessment are presented, from both economic and ecological point of view. For each one of these two approaches, the concept of value, valuation methods and applicability are analysed. The second part of the thesis presents a method that can be used by planners to select an optimal land use plan among alternatives. The method focuses on spatial dimension of economic activities and of ecosystems conservation. The model has a multicriteria structure, based on two objectives: economic efficiency and ecosystems conservation (that are contrasting elements of sustainable development). In the fourth chapter the framework of the model is illustrated, and its application in planning processes is explained. The fifth, and last, chapter presents the parameters used in the model to quantify the two objectives: Economic Index and Quality Index. The Economic Index measures the economic efficiency of a certain landascape structure (proposed by a land use plan), while the Quality Index quantify landscape structure ability to protect natural systems. These indexes are constructed referring to principles and instruments of specific disciplines: respectively, Regional Economy, which affects the relationship between land use and economic efficiency, and Landscape Ecology, which investigates the relationship between land use and ecosystems health. Conclusions summarize thesis contents and highlight difficulties and further research possibilities