1. Seismic vulnerability of the city and urban form

On a properly urban scale, the “response ” of a town to a seismic event depends also on the many features and condition of the town’s buildings. But firstly, the features and layout of the settlement are of key importance in these situations, and they can be linked to the concepts of urban structure and urban fabric, key concepts in the study of towns and urban design. The concept of urban structure has been defined and dealt with by many authors in the history of urban-planning, and on the basis of extremely different viewpoints and approaches. The main recurring and important meaning, and which is also of particular interest concerning the studies on urban seismic vulnerability, selectively refers to a system of places – poles and connections – of primary importance in a town. Therefore, it is a selective and targeted concept, intended to bring out what are the most “important ” aspects (from