Adopting GMS-PSO Model to Reduce Groundwater Withdrawal by Integrated Water Resources Management

In arid and semi-arid regions, groundwater management is vital due to over abstraction for supplying water demands. Integrated water resources management is the main approach to prevent groundwater over abstraction using available surface water and treated wastewater which is the goal of this research. In this research, aquifer simulation by GMS software was adopted to identify Hashtgerd aquifer (in Iran) system and estimate its groundwater balance. The basin is divided into four zones due to difference in water demand and available water. Particle swarm optimization (PSO) method is applied to minimize the discharge of groundwater by maximizing surface water against water demand in each zone The results of the simulation model indicate that groundwater budget of Hashtgerd plain is negative, which reservoir storage loss is almost 17 MCM per year (2011-2012). The results of the optimization model indicate that the most increases of the aquifer storage are in November, April and February, respectively, and the discharge of groundwater in all zones of basin is located at the borderline for 60% of months. According to conditions in the plain and the results of the optimization model, the groundwater withdrawal more than presented values should be forbidden when the reservoir storage changes is zero, then the maximum use of surface water and wastewater could avoid more groundwater declination. Finally, the best solution to manage water resources to avoid over abstraction is the conjunctive use of all water resources (surface water, groundwater and wastewater) within each zone.