Application of Fuzzy and FEMA Modified Methods in Risk Assessment of Man-Made Threats in Water Systems

Bacground and objective: Assessing the threats and vulnerabilities of infrastructure is one of the major concerns of security officials in a country, and water supply systems are one of the most important and sensitive infrastructures. Water supply systems are also among the basic infrastructures that are very important in assessing the threats in these systems and identifying its weaknesses. In this regard, in the present study, in addition to assessing the risk of a water system with existing methods, we intend to correct and update these methods and examine its results. Method:The present study is a practical application in terms of nature and a combination of descriptive-analytical and quantitative methods in terms of implementation. In this study, in addition to field visits and interviews with relevant experts in the field of study to perform calculations and risk assessment of water systems, two methods of FEMA and Fuzzy risk assessment have been used as well as modified of these two methods. Finding:The results of the assessment of the water level of Samah studied in the present study using FEMA method, indicate high risk in facilities 4 to 6, low risk in facilities 7 and 9 and medium risk in other facilities. In the Fuzzy method, in addition to facilities 7 and 9, which have medium risk, other high-risk facilities have been identified. Also, the results of the modified FEMA method (managerial FEMA) indicate high risk in facilities 4 to 6 and medium risk in other facilities. Also, according to the results of Kai-Esquar test, fema and fuzzy tests are significant in two levels of 1 and 5%, but the modified methods in these two levels are not significant. Conclusion:The results of the Fuzzy method in this study are closer to the real conditions of the system under study, so it can be used as a native method in the study area. Due to studies in a water system, the insignificance of the results of corrective methods is not a reason for the inefficiency of these methods and more studies can be done in this field.