Forms and Processes of Settlement Pressure on Natural Systems

The process of urbanisation is considered one of the most significant anthropic alterations of the environmental framework, and the present study attempts to understand the spatial characteristics of urban growth and their impacts on envi- ronmental components in two metropolitan areas of Sicily. Such rapid and unplanned urbanisation in Sicily has increased during the last three decades causing severe pres- sure on various natural resources. In this situation, the level of fragmentation and isolation of natural areas risks becoming worse. The question assumes a particular relevance in those local territorial portions, such as some urban and periurban areas, presenting relevant conditions of naturality close to highly built environments. Such landscapes are usually affected by forms of human pressure that have determined intense deterioration processes, that urban and regional planning tools were not able to control and reduce. Empirical evidence of this study suggests that alternative urban patterns generate differential effects on the environmental system. Starting from this evidence, in this article we explore the reciprocity relationship between built envi- ronment and open territory, with the aim of identifying possible strategies to manage the phenomena of urban sprawl in the metropolitan context.