The Presentation of Environmental Risk Assessment Pattern for Gas Pipeline Project by Using of Indexing System and AHP Methods (Case Study: Transportation Pipelines 24 inches, Tasuj-Salmas Project)

In this study for purpose of environmental risk assessment for gas transportation pipelines, combined the indexing system method and AHP. Indexing System is a compulsive and applicable method that was based at the basis of characterizing index effect and ranking. For the purpose of weighting the criteria’s, the AHP was used and for the purpose of weighting the digital layers of information’s related to the criteria’s, Ordered Weight Analysis method was used. Via usage of GIS abilities, the identified risks and risk zonation in the path of pipelines. Results showed that 46% of gas pipeline, has a high risk (5467- 6054 grade), 48% of it, has a medium risk (6055- 6641 grade), 2% of it, has a low risk (6642- 7228 grade) and 4% of it, has a little risk (7228