Vulnerability Analysis against Natural and Technological Threats: A Comparative Assessment in Tehran Metropolis Gas Supply NetworkXML | views: 1 | pages: xxx-xxx
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.
Development of a Method for Evaluating the Ports Environmental Performance Based on Fuzzy Analytic Hierarchy Process (FAHP)XML | views: 2 | pages: xxx-xxx
Introduction: Appropriate environmental performance is considered as one of the important indicators in the sustainable development of organizations and industries. Evaluating the environmental performance in ports as one of the two main parts of the maritime transport system is very important. Therefore, this study was designed and conducted aimed at developing a method for evaluating the environmental performance of ports based on fuzzy analytic hierarchy process (FAHP).
Methods: 22 experts in the field of environment and marine sciences took part in the present study in 2020. In the first step, various studies on the factors affecting the environmental performance of ports were reviewed. In the second step, a questionnaire was designed to assess ports environmental performance. In the third step, in a Delphi study, this questionnaire was developed. In the fourth step, by determining the weight of each parameter, the method of environmental performance assessment in ports was developed based on the FAHP.
Results: The final normalized weights for six environmental performance factors including reactive and proactive performance, sustainability, socio-cultural, economic and governance were estimated 0.202, 0.241, 0.226, 0.070, 0.080 and 0.182, respectively. Additionally, it was found that each of the parameters has different weight and impact on these factors. The highest and lowest impact on environmental performance index belonged to environmental risk assessment (weight=0.217) and cultural effects and justice (weight=0.107), respectively.
Conclusion: In this study, a new method has been developed for evaluating the environmental performance of ports based on six factors and 32 parameters and FAHP. Therefore, using this method can be an effective step in reducing environmental impacts and improving the level of environmental performance in ports to achieve the goal of "green port".