Optimal location of pumping wells by a mesh-free numerical method

Abstract

In the present study, the optimal place to excavate extraction wells as the drawdown is minimized was investigated in a real aquifer. Meshless local Petrov–Galerkin (MLPG) method was used as the simulation method. The closeness of its results to the observational data compared to the finite difference solution showed the higher accuracy of this method with a root mean square error for MLPG of 0.757 m compared to the finite difference which equaled 1.197 m. Particle warm algorithm was used as the optimization model. The objective function was defined as the summation of the absolute values of difference between the groundwater level before abstraction and the groundwater level after abstraction from wells. In the Birjand aquifer, which was investigated in transient state, the value of objective function before applying the optimization model was 2.808 m, while in the optimal condition it reached 1.329 m (47% reduction in drawdown). This was investigated and observed in three piezometers. In the first piezometer, the drawdown before and after model enforcement was 0.007 m and 0.003 m, respectively. This reduction occurred in other piezometers as well. HIGHLIGHTS In the present study, using a simulation–optimization model, the best place to bore a well in a real aquifer under transient conditions was discussed.; The meshless local Petrov-Galerkin method as simulation model was used.; The water level in a real aquifer was modeled in transient state and compared and verified with the results of finite difference numerical method.;

Keywords

• meshless local petrov-galerkin method
• meta-heuristic algorithm of particle swarm
• optimal location of well boring
• unconfined aquifer