Derivation of conflict resolution rule-curves in multi-purpose multi-reservoir system for inter-basin water transfer during drought

Allocation is the number-one cause of conflict in water resources, whether between sovereign nations, different user groups or neighboring basins. The inter-basin water transfer is a remedy to the negative issues of water shortage in drought-stricken regions. In a water transfer project, the receiving basin always benefits while the donor basin may suffer. In this work, to define an operating policy, a multi-reservoir multi-purpose system is simulated and optimized for a set of long-term historical records. A multi-objective optimization model is developed based on Non-Dominated Sorting Genetic Algorithm (NSGA-II). The optimization results define the best possible performance set for a twobasin system with the objectives of supplied water shortage minimization during droughts. In a multi-objective optimization problem, there is not a single solution that simultaneously optimizes all objectives. However, decision makers are concerned with finding a unique compromise solution that balances conflicting objectives in a socially acceptable manner. The game theory can identify and interpret the behaviors of parties in water resource problems and describe interactions of different parties who give priority to their own objectives, rather than system’s objective. Using the strategic form description for different moves or actions available in the optimum trade-off front, Nash equilibrium outcomes predicted by game theory narrow the results suggested by optimization method. In this study, the inter-basin water transfer project from Zohreh multi-reservoir multi-purpose system in southwestern Iran to the Persian Gulf coastal district is investigated using the proposed methodology.