Clustering of Crowded Urban Places from the Perspective of Passive Defence

Although in recent years, the issue of passive defense has become one of the key issues in the field of national security, but there is still a long way to go to reach the desired situation. Cities, and especially crowded places, are one of the environments that are always faced with a variety of threats due to the large population with high density. In fact, open access to crowded places greatly increases their potential vulnerability to military and political centers. Although the military attack is considered as the most important threat to military and political centers, threats to crowded places are military attacks, bombings, suicide attacks, car attacks, hostage-taking, strikes and internal insurgency, cyber-attacks and etc. Therefore, the present study tries to analyze the vulnerability of various crowded places in a descriptive-analytical method based on documentary studies and Delphi method. In this regard, 23 types of crowded places in cities have been identified and the extent of their impact from various threats has been determined based on receiving the opinion of an expert group (25 experts). The data is validated based on nonparametric analysis models and Kendall coefficient test in SPSS software and analyzed by the Hierarchical Clustering method. The findings show that if crowded places are clustered based on the most similarity in terms of threats, the "railway station" and "airport" fall into one cluster with the highest vulnerability. Also, "Metro Station", "Passenger Terminal", "Shrine of Imams / Imamzadehs", "Jameh Mosque" and "Mosque and Hosseiniyah" are located in a cluster with relatively high vulnerability. In the third cluster exists "mourning and marching paths", "assembly hall", "passage / department store", "sports stadium" and "cinema and theater" which are associated with moderate vulnerability.