Numerical modeling of Saltwater Wedge under Intruding and Receding Conditions (Case Study: Kahriz Aquifer, Lake Urmia)

The complexity of saltwater intrusion issues caused, they cannot be solved analytically, so numerical methods can be useful tools for simulation and prediction of saltwater intrusion. In this study, CTRAN/W as a finite element-based model, and SEAWAT as a finite-difference model were employed to simulate the behavior of the saltwater wedge in three states including steady and transient flow. Results of numerical modeling were compared with observed published data and the precision of the models evaluated using various statistical parameters. Based on the results, both models capable to simulate saltwater intrusion with high precision. Furthermore, Kahriz aquifer located at the northwest of Lake Urmia has been modeled underground water level oscillations. The results of this part showed that just 4 m dropping of groundwater level leads to the intruding of saltwater two times in comparison to the reference level. The finding revealed that the time to reach the steady-state conditions for receding saltwater wedge is 60% of that for intruding saltwater wedge after rapid water level changes.