Numerical Studies of Ground Water Flow near a Partially Penetrated Well and an Alluvial River

The Mississippi Delta is a productive agricultural area in the United States, the agriculture, however, heavily relies on groundwater. In the last decades, the ground water table has experienced a significant drawdown. The current way of using groundwater is not sustainable. This problem has drawn attention of water resource management agencies and research community.

In this study, a newly developed 3D groundwater model, CCHE3D-GW, was used to analyze this problem. The model is verified using analytical solutions including a stream depletion case considering the effects of both pumping and surface water charging from a stream (Butler et al. 2001). Several scenarios with different ratios between the conductivity of streambed and aquifer were simulated. The agreements between the simulation results and the analytical solutions verified the model.

The model was then applied to the pumping tests of a USDA project in Money, Mississippi. The pumping site is very close to the Tallahatchie River and the relations between the pumping and the surface water charging is studied. The complex conditions of the aquifers, river morphology, and sediment bed have been incorporated in the numerical model and preliminary simulation results have been obtained. Additional study is in progress. The results will be reported in the conference.