Modeling the impacts of various managerial scenarios on groundwater level raising in a coastal aquifer

Groundwater abstraction management is one of the most fundamental steps towards the sustainable development of these resources. Recently, due to the excessive extraction of these important resources, the amount of groundwater storage has gradually depleted and the water scarcity crisis has worsened. In the groundwater depletion areas, managerial decisions can provide proper solutions to help change the rate of exploitation. Relying on mathematical models and through observation of the implications of such decisions, the best solution can be selected, and therefore, the sustainable use of groundwater may improve. One of these crisis-inflected aquifers is Shabestar’s coastal aquifer located in the Urmia Saline Lake basin in northwestern Iran. In the current study, the Shabestar Plain aquifer was simulated by the MODFLOW mathematical model and 18 scenarios were defined for preventing water table reduction. This study tries to manage the groundwater resources and utilizations with different scenarios for sustainable use from the aquifer. These scenarios include changes in the extraction amount, close-off, or integrating several illegal abstract wells. For the first time, in the current study, the effectiveness of each of these solutions on the water table was investigated first separately and then collectively with other solutions. The results are indicative of a significant increase in the groundwater level in the scenario of extraction reduction from licensed agricultural wells due to a 30–40% decrease in licensed extraction from groundwater or through closing off all illegal wells along with a 20% decrease in extraction from licensed wells. The trend of reduction in the aquifer’s water table can be slowed down, and the table can be maintained from the moment of application of these scenarios. Moreover, based on the modeling applied, closing off all illegal wells in the region or integrating them would lead to a 20 and 10% reduction in the extraction from the licensed wells in the area, respectively.