The necessity of making use of Urban Underground spaces in passive defense in order to protect and urban security

Increasing global threats due to the geopolitical position of Iran on the one hand , and The increasing trend of urbanization and More than two thirds of its population living in cities on the other hand, has made it necessary to achieve a dynamic and effective solutions to protect life and property and ensuring peace and normal life of citizens after any possible crisis. This study wants to tell us that beside concepts of crisis management and non-operating defense are the same, by introducing a new approach in urban design-that means mixed-use design of third city dimension or use of urban underground spaces-it can pay attention to high potential of them for providing basic demands and requirements of crisis management and introduce us the model consideration as the research result