Morphological systems of open spaces in built environment prone to Sudden-onset disasters

Recent events have shown how the Built Environment (BE), defined as a network of buildings, infrastructures and open spaces, and its users are more and more prone to disasters, showing very poor resilience. The paper focuses on the state of the art concerning the relation between BE and Sudden-onset disasters (SUOD) considering the risks and human behavior. Results concerning the char-acterization of BE prone to SUODs underline the primary importance of open spaces in the Built Environment, as elements to characterize in respect to the possible emergency phases and the behavior of the BEs users. Attention is given to the BE constituting the base elements for urban areas (i.e. compact historic city) because of the related risk-affecting specific conditions (i.e. crowding, com-plexity of overall BEs form, built element features, BEs uses). Moving from dif-ferent open spaces types classification, the paper defines morphological classes of BE representative of the variables of urban systems that interact with the iden-tified SUODs risks.