Optimizing Stakeholder Behavior for Groundwater Management in Arid and Semi-arid Climates: A Multi-agent System Approach in Karaj Plain, Iran

The ever-increasing water demand has not only disrupted the demand-supply balance, causing conflicts among multiple stakeholders, but has also led to environmental impacts due to aquifer depletion. Today, agent-based modeling (ABM) is recommended for studying the effects of stakeholders’ social aspects on water resources, particularly groundwater resources. Aim of this study proposes a model for optimizing stakeholder behavior, which is coupled with numerical groundwater resource simulation and water resource optimization models in Karaj Plain, Iran. The simulation results of the aquifer showed that continuing the current situation will cause the aquifer level to drop by about 5 m. However, implementing the water resource optimization model, with goals of reducing water shortages and improving underground water conditions, will increase the aquifer reserve. This model will also provide 99.7% of the region’s drinking water at a rate of 3.03 MCM per year, raising the aquifer level by 3 m. Additionally, the optimization model of beneficiaries’ behavior and the analysis of proposed scenarios demonstrated that reducing agricultural water rights, combined with policies aimed at changing agents’ behavior in the agent base model, would increase the average groundwater level across the entire aquifer by about 5.5 m. Taking into account the local knowledge of the main water consumers, it is recommended to use multi-agent system models to incorporate the ideas of other agents (decision-makers) and develop the proposed cultivation pattern for effectively managing water resources and reducing environmental risks in arid and semi-arid climates.