Author(s): Jiayu Fang, Yafei Jia, Yavuz Ozeren

Linked Author(s): Jiayu Fang, Yafei Jia, Yavuz Ozeren

Keywords: Mississippi Delta; River-aquifer interaction; Groundwater model; Pumping test;

Abstract: A newly finite element based numerical model, CCHE3D-GW, was developed to study the drawdown process affected by the free surface water in the river. The numerical model was verified with the analytical solutions considering pumping and surface water infiltration conditions. Two-dimensional analytical solutions were used to verify the model using both its 2D and 3D mode. A 3-day pumping test was conducted near the Tallahatchie River in Money County, Mississippi, USA, as a part of a groundwater pumping and recharging project in the Mississippi Delta. The stabilized drawdown level is determined by the balance of the pumping rate, river flow infiltration and the groundwater supply. The area of the field simulation case is 20.3×28.6 km2 based on a simplified aquifer distribution: a 40 meters thick sandy aquifer is laying on an impermeable layer and under a 10 m clay aquitard. The river stage at the pumping site was unsteady, which dropped around 0.3m during the 3-day pumping period. Calibrations of the hydraulic conductivities of the aquifer, aquitard and riverbed wereconducted. The simulation results generally agreed with the measured data. The results show a good potentialof further applying this model for the pumping and recharging pilot project. Further studies using more realisticaquifer information will be conducted for improved results.

DOI: https://doi.org/10.3850/38WC092019-1104

Year: 2019