Extraction of Conjunctive Hedging Rules for the Operation Management of Surface and Groundwater Resources

In this study, the WEAP model was used for the simulation and the Gravitational Search Algorithm (GSA) was applied as the optimization model. Due to the necessity of multiple simulations in the optimization process to achieve the optimal solution, the linkage of simulation and optimization models was done in the MATLAB software environment. To evaluate the performance, hedging policies achieved in the base period were investigated for the near future period under climate change. The results showed the poor state of aquifers under the baseline scenario; also, the continuation of the current management caused the Zayandehrood river basin to experience significant problems. So management of water resources using conjunctive hedging policies could improve the situation. The use of conjunctive hedging rules showed 11 percent increase in the group sustainability index for demands, in comparison with the baseline scenario. Also, according to the group sustainability index for the resources, applying the conjunctive hedging policies could increase the sustainability of surface water and groundwater resources as much as 5.2 and 6 percent, respectively, relative to the baseline scenario. The results also indicated the better performance of conjunctive hedging policies in comparison to the baseline scenario policies.