Application of fuzzy ELECTRE TRI method for determination of environmental impact significance of water resource development projects (the case of Ardebil Dam, Drainage and Irrigation Network Project)

The large scale water resource development projects have in many cases recognized as the sources of diversified complex environmental impacts. Proper assessment of these impacts requires devising novel approaches to deal with the multiple aspects of the impacts per se, as well as to apply rather quantitative techniques to make more reliable and less uncertain synthesis of the overall consequences of the project activities on both the integrity and health of the surrounding environment. Analysis of the significance of the environmental impacts is a multiple criteria decision making problem and makes the core of the conventional environmental impact assessment methods. However, these conventional measures of significance analyses are proved to be inadequate for dealing with imprecise, vague and uncertain nature of the linguistic assessments of the ecological, social and cultural impacts. A new numerical method called the fuzzy outranking sorting technique for ELECTRE TRI (ELimination Et Choix Traduisant la REalite) is proposed and applied in this research for the purpose of environmental impact significance assessment of the Ardebil Dam, Drainage and Irrigation Development Project in Northwestern Iran. The basic idea behind the research was to develop a methodological framework in order to assist the environmental impact analysts in reducing, as much as possible, the intrinsic imprecise and uncertain traits of the multi-expert judgment based methods currently used in the analysis of environmental impacts of the projects. Compared to the compensatory MCDM techniques, ELECTRE TRI provides the advantage of using a fuzzy approach in the analysis of the vague and poorly determined set of judgment data and helps in more credible assignment of values to a set of predefined categories with respect to a set of impact criteria. Results of the Fuzzy ELECTRE TRI based analyses are compared with a conventional method, which has used for the environmental impact assessment of the same project. It is argued that due to its multiple criteria and fuzzy characteristics, the ELECTRE TRI method is capable of producing more reliable inputs for the decision making process compared to the conventional additive techniques.