Performance Assessment of Numerical Solution in Simulating Groundwater Recharge

Abstract

Aquifer regeneration is one of the essential primary solutions to better the crisis of these resources. Optimum locating of injection and considering the influencing factors of the aquifer's features are the most critical issues that have always been challenging for researchers. Hence, this study addressed the efficiency of two developed numerical methods in simulating artificial recharge. For this purpose, three scenarios were defined to evaluate the performance of numerical methods (comparison of analytical and numerical solutions), simulating the rise of the groundwater level, and analyzing the sensitivity of the hydrodynamic features of the aquifer. The concept of two numerical methods (i.e., Finite Difference 'FD' and Finite Element' FE') was performed as open-source coded in MATrix LABoratory (MATLAB), and their efficiency was examined. Results indicated that the simulated groundwater drawdown due to extraction wells is compatible with the analytical solutions regarding RMSE and NSE. Also, the performance evaluation results showed that the accuracy of the FE method is better than the FD. The experiment's results of artificial recharge into the aquifer through the injection well also showed that the groundwater level rise in the FE method is faster than in the finite difference method. Also, after 1500 days of recharge, the height of the groundwater level is up to about 90 cm.

Keywords

• anisotropy
• heterogeneity
• specific yield
• transmissivity
• weighted residual methods