m mahdavi adeli - Professor Assistant of Department of Civil Engineering, Shoushtar branch, Islamic Azad University, Shoushtar, Iran.
m azadi - Master student of Department of Civil Engineering, Shoushtar branch, Islamic Azad University, Shoushtar, Iran.

Urban water supply network as an integral component of every city is responsible for providing and transporting water which is the most critical needs of the community. Any problem in this system impairs citizens' access to water. In the event of an earthquake or war or other threats, transmission and distribution networks are at risk of serious damage and vulnerable. In designing water supply facilities, it is necessary to consider security infrastructure to cope with the crisis,in addition to the usual considerations of design. This subject is studied in terms of passive defense engineering. Engineering passive defense is necessary to reduce risk, control consequences of crisis and increase repair ability which is discussed by implementing seemingly simple principle, but it is complicated in design and implementation. In this paper, sensitivity and risk-taking of different components of the water supply system with defensive measures is examined. Thus, strengths and weaknesses of each are identified and passive defense research priorities are determined for water supply facilities

Supply networks , Passive defense , Safety design , Risk , Vulnerability