Development of a Multi-criteria Decision Support System for Water Resources Allocation in a basin (Case Study: Mazandaran-Golestan Water Conveyance System)

Water resources management in the basins has a wide and complex dimension, which is always faced with challenges such as environmental, socio-economic impacts, especially for decision-making on water transfer among basins. In this research, a multi-criteria decision Support system has been developed to allocate drinking, industrial and agricultural water and transfer water from Mazandaran to Golestan Provinces. Planning water resources, determining transferable surplus water by WEAP model, determining various coefficients of economic, social, technical, water resources and environmental criteria using Expert Choice software and their connection by Excel software were performed. Three Alternatives for transferring water including 1: transferring water from agricultural land upstream with Chalous excess water 2: transferring water from agricultural land upstream without Chalous excess water 3: transferring water from agricultural land downstream near the sea were defined and evaluated using multi-criteria evaluation. The results of the model showed that allocation of 82.2 million cubic meters for drinking and 10.5 million cubic meters for agricultural uses, considering the economic, social, technical, water resources and environmental criteria, is the optimum alternative for transferring water from Mazandaran province to Golestan province (Alternative 2) and it has the highest score (7.33) in the multi-criteria evaluation. Multi-criteria decision support system model was developed on the basis of the selected option, so that it is possible to examine different scenarios and can help decision-makers and planners to plan and allocate water resources at the basin level. The outputs of the model showed that considering economic indicators lonely could not lead to a proper decision for allocating water resources, especially for water transfer between the basins. Thus, in addition to economic considerations, it is necessary to consider the social, environmental, water resources and technical criteria using a multi-criteria evaluation.