Application of the Nash Conflict Resolution Model in Operation of Reservoir Systems

Reaching a compromise between stakeholders of reservoir systems is one of the delicate and complicated subjects in water resources management. Game theories in general, and the Nash conflict resolution model in particular, are such methods that consider the existing conflicts and utility functions of each stakeholder, and search for an optimum solution in the decision space. In this research, optimal operation of a three-reservoir system has been considered with hydroelectric energy generation as well as supplying downstream demands objectives. To specify the effects of the defined objectives, stakeholders of each reservoir and their utilities were introduced simultaneously. Afterwards, all objectives were considered separately. Results showed that the utility of stakeholders for each reservoir in separated objectives was increased. In the next step, to compromise between different stakeholders (hydroelectric energy generation and supplying downstream demands), stakeholders’ utility was used in the Nash function. As a result, a solution was reached through which most of the utilities for all stakeholders were provided at the same time. Next, the reservoirs systems were divided into the parallel upstream reservoirs and a single downstream reservoir. Each reservoir’s stakeholders tried to generate more hydroelectric energy and supply as much flow as the downstream demands. Results show that the total system utilities equaled to 5.872 units in the last step, which was 0.472 % more than total system utilities of the separated reservoirs