عنوان مقاله [English]
The nature and essence of cities are intermingled with different issues such as political, economic, cultural, physical, juridical and environmental subjects. Therefore, “urban security” is a hybrid and complex concept. Because, city is influenced by many national and global units. Thus, designing a defensible urban space is one of the most important topics in securing metropolises. These spaces may include designing secure residential spaces, integrating public spaces with different land uses (commercial centers, governmental offices and other important organizations), controlling population density in important urban areas in different time periods and improving transportation systems and crisis management. With access to comprehensive information and general data, we can prepare a map of urban crisis and improve urban security and safety by implementation of optimal solutions. The pattern of spatial changes in cities and the framework of urban land use are among the most important issues in urban security and safety which indicate the importance of passive defense planning. Urban spatial planning is among the most important leverages which shows the vulnerability of different urban areas in the case of natural and human crisis in different time and locations. Urban security and safety depends on very complex patterns of density related causes and multiple effects. The complexity of these patterns suggests that providing simple commentaries and describing specific causes have a limited value in optimizing urban security and safety. The present article seeks to evaluate the role of passive defense in providing and optimizing security of metropolises, and suggests fundamental strategies for decreasing secondary crisis (after the occurrence of primary crisis such as flood, earthquake, fire and urban chaos. It seems that the passive defense approach is a new strategic view in establishing the security of metropolises and building a healthy and secure city.