Vulnerability Analysis against Natural and Technological Threats: A Comparative Assessment in Tehran Metropolis Gas Supply Network

Introduction: Resilience as a counterpoint to vulnerability can reduce the vulnerability of various natural, man-made and technological threats in complex technical systems. The present study was designed and conducted with the aim of comparative assessment of the vulnerability of the gas supply network to natural and technological threats. Method: This study was carried out in the form of a descriptive-analytical and cross-sectional study in Tehran metropolis gas supply network including town board stations, gas supply and distribution networks in 2019-2020. This study is based on vulnerability analysis method including three factors of likelihood, severity of consequences and the degree of preparedness for threats. Comparative vulnerability assessment in these three sections of the gas supply network was performed using IBM SPSS software v. 23.0. Results: The findings showed that out of eleven identified hazardous elements, the vulnerability index for three hazardous elements were estimated in the weak level threat, four hazardous elements in the medium level threat and the vulnerability index for four hazards were aevaluated in the severe threat. The results of comparative vulnerability assessment based on three parts of the gas supply network showed that the highest vulnerabilities belong to the gas distribution network (133.66±24.63), gas supply network (115.0±35.35) and town board stations (79.49±68.51), respectively. In addition, the results of Kruskal-Wallis test showed that the vulnerability difference in these three sections was not significant (p>0.05). Conclusion: The findings of the comparative assessment of vulnerability between different parts of the gas supply network including town board stations (TBS), gas supply and distribution network indicated that the resilience of these parts were relatively low and require special attention to reduce vulnerability in the Tehran metropolis gas supply network. Keywords: Comparative assessment, Vulnerability analysis, Resilience, Gas supply network, Tehran Metropolis