In last few decades conflict-resolution models are being increasingly used in water resource management for cases such as the groundwater problems as an appropriate approach to consider the oppositions and trade-offs between the stakeholders involved in the conflict and to reach to an applicable optimal resolution. In this paper, by integrating simulation-optimization models of groundwater exploitation and bargaining methods, the optimal allocation scenarios are derived taking into account the preferences of the stakeholders and social criteria such as justice. Trade-off Pareto front between the rival objectives was computed through linking the NSGA-II multi-objective optimization model and M5P meta model which was trained and validated based on MODFLOW simulation results. Monte-Carlo method was used to develop a database for training and validating meta models for different allocation scenarios.
Considering multi-objective nature of the problem, the best solutions on Pareto fronts were selected using fallback bargaining models. The effectiveness of the proposed methodology was verified in a case study performed on Daryan aquifer, Fars province, Iran. Results indicated that the total groundwater withdrawal after applying the optimal scenarios of allocation was reduced approximately 56% which resulted in the mean water level uplift of 4.2 meters in the aquifer.