Natural Cities and New Italian Urban Regions. The Role of Medium-Sized Urban Areas in Italy

The contribution intends to examine the concept of natural city, starting from the hypothesis that the administrative boundaries of cities and regional entities are not able by themselves to capture the dynamics of territorial coalescence in progress. Urban systems are progressively increasing connections and their networks (not only physical) are consolidating, producing welding phenomena that create polycentric urban regions. Two distinct but integrable territorial analysis strategies are analysed: the survey and measurement of the degree of physical density of the settlements and a general strategy capable of capturing the commuting basins. The Italian urban system, thus, can be observed from the combination of these two analytical strategies, showing the emergence of medium-sized urban regions (between 50,000 and 300,000 inhabitants) which constitute the territorial and economic 21st century skeleton of Italy. These are very dynamic urban regions that are positioned between metropolitan Italy and the internal areas. Finally, we analyze a multi-temporal rank-size model of Italian urban regions, constructing scenario where the settlement peculiarities at the macro-regional level emerge. An initial analysis at a temporal level (releasing up to the 1950s) reveals how the Italian urban system has been changing, giving greater weight to medium-sized natural cities, even in a landscape of demographic decline.