Modeling of a Groundwater Mound in a Two-Dimensional Heterogeneous Unconfined Aquifer in Response to Precipitation Recharge

The paper deals with the transient semi-analytical solution of linearized Boussinesq equations characterizing the development of groundwater mound in an unconfined two-dimensional heterogeneous aquifer under vertical recharge conditions. The finite aquifer consists of two rectangular basins surrounded by open water bodies and shares a common impermeable or permeable boundary at the mid plane. The governing equations are solved by applying the Laplace transform and finite Fourier sine transform techniques. Accordingly, analytical expressions for water heads for two rectangular basins are obtained for various scenarios. The applicability of the solutions has been illustrated with the help of a case study and numerical examples, considering various cases. The region wise development of the groundwater mound indicates that the effect of heterogeneity becomes significant for small time duration whereas for long time it becomes insignificant. This result can have application in land reclamation problems in the presence of localized recharge where the reclamation displaces the ground water divide and changes the groundwater conditions in the entire region.