Evaluation of saline water intrusion treatment strategies using numerical simulation (Case study: Astaneh Kuchesfahan plain aquifer)

One of the new challenges in exploiting groundwater resources is seawater intrusion. Unplanned increase in exploitation reduced the groundwater level, which reduced the hydraulic gradient of the shoreline and in some areas reverses the groundwater flow and leads to groundwater salinization. This study examine the seawater intrusion strategies in the Astana-Kuchesfahan coastal aquifer using numerical simulation. Examination of the current status of this aquifer using SEAWAT package was indicated the intrusion of 740 meters of seawater to the aquifer over a 5 years period showed that in order to manage this pressing matter, 19 management strategies (reduction of groundwater exploitation), structural and subsurface dam) and integrated (managerial and structural) to reduce the seawater intrusion was presented. The simulation results of different treatment strategies were evaluated using the aquifer qualitative stability index, which is based on the amount of saline water regression. The results showed that this index was calculated between 14% and 65% for the defined solutions. The highest relative aquifer improvement is related to S18 solution with 20% reduction in groundwater exploitation, artificial recharge and subsurface dam and the lowest relative aquifer improvement is related to S1 solution with 5% reduction in operation. The results showed that S1 solution was associated with 100 m water retreat and S18 solution was associated with 480 m saline water retreat. The results can be used for groundwater exploitation management in this coastal aquifer.