Terrorist Risk in Urban Outdoor Built Environment: Influencing Factors and Mitigation Strategies

Abstract

Starting from the established and common principles of the terrorism threat in the cities, this chapter presents the results of the phenomenological analysis in Europe and reorganizes the main literature and international experiences in the prevention, mitigation, and management of the threat in the built environment in order to delineate the factors that influence the risk of outdoor Open Areas (OAs) as “soft targets”. In fact, if several previous experiences have already investigated the effects of events on people involved, the strategies used by perpetrators and tested mitigative strategies in detailed case studies following an “a posteriori” approach, a unique approach to describe and discuss the risk of OAs seems to be still unexplored. The aim is thus reached by merging two levels of details. I) The assessment of events during the last 20 years in Western Europe allows to understand how (the attack type) and why (which uses affect the likelihood of events) OAs are emergent “soft targets”. On the other hand, II) the critical categorization of Risk Mitigation and Reduction Strategies already experimented and regulated in the international panorama helps in highlighting how such soft targets can be physically improved towards resilient parts of the cities.