Field Measurements and Numerical Analyses of a Pumping-Recharge Test in a Deep Confined Aquifer

Abstract

Pumping-induced groundwater drawdown and strata deformations can be relieved by artificial recharge. In this study, field measurements and numerical analyses of a single-well pumping with multi-well recharge test are presented to investigate the responses of groundwater and strata to pumping and recharge. A three-dimensional numerical model is developed in a finite-difference software, which considers the fluid-mechanical interaction using the Biot consolidation theory. Both measured data and numerical results indicate that the influence of recharge on the groundwater drawdown caused by pumping correlates with the injection rate. A larger injection rate may result in a greater decrease of drawdown. As artificial recharge can compensate the drawdown by injecting water into the aquifer, the change of effective stress of soils induced by pumping can be reduced. Consequently, pumping-induced strata settlements and ground settlements can be relieved by artificial recharge. Therefore, artificial recharge can be used to reduce the groundwater drawdown and ground settlements during the pumping and protect surrounding facilities from settlement caused by pumping, if an appropriate injection rate and well arrangements are determined.