A fuzzy multicriteria benefit–cost approach for irrigation projects evaluation

Three alternative irrigation projects for the East Macedonia-Thrace Region, Greece, are considered. Given the presence of valuable natural ecosystems in the area, environmental considerations are of great importance. In order to evaluate the projects, a fuzzy multicriteria benefit–cost approach is proposed. The overall goal is the rational management of water resources, and the projects appraisal is based on economic, social, and environmental criteria. Alternative scenarios on the availability of water resources are also incorporated in the decision model. The decision problem is formulated as two hierarchies, and the projects are ranked according to the benefit–cost ratio of their global priorities. The proposed method is proved to be, on the one hand, very suitable when both costs and benefits cannot be easily expressed into monetary terms as the traditional benefit–cost analysis requires; and, on the other hand, a valuable tool to cope with vague judgments.