In this study, a new methodology is proposed to balance environmental and economic issues in water allocation under uncertainty. Two objective functions, including maximizing economic income (EI) and minimizing environmental pollution (EP), were considered as two groups of players to construct a deterministic multi-objective bargaining methodology (DMOBM). In the next step, it is enhanced to a robust multi-objective bargaining methodology (RMOBM), which is capable of incorporating the main uncertainties exist in the problem. A large-scale inter-basin water transfer case study was utilized to investigate the applicability of the developed model. The outputs of the models showed that Nash equilibrium provide a rather narrow range of solutions. According to the results, the required rounds to reach Nash equilibrium raised as the uncertainty level increased. In addition, higher levels of uncertainty lead to higher reduction in water allocating of receiving basin. Sensitivity analysis showed that economic income values are less sensitive to changes of uncertain parameters than the environmental objective function. The developed methodology could provide a framework to incorporate the behavior of different stakeholders. Furthermore, the proposed method can be reliable under the condition of facing water allocation uncertainties.
