Comparison of Simulation Methods for Recharge Mounds Under Rectangular Basins

Various methods for predicting recharge mounds that form beneath basins during recharge and the subsequent decay after recharge stops have been developed over the past half a century. In this paper several analytical methods were compared for very rapid, rapid and moderately rapid hydraulic conductivity values. Subsequently, the results were matched with numerical methods. Results obtained indicate minimal deviations among analytical solutions for predicting infiltration mounds at low recharge time (≤50 days). In addition, the deviations can be easily amended. Numerical solutions predict higher infiltration mounds (up to 32 % for the results chosen) compared to analytical methods, a variation attributed to the fewer assumptions made when solving governing groundwater equations. Yet at the lowest hydraulic conductivity rate (1.6 m/day) used in this investigation, numerical solutions are comparable to analytical solutions. Despite general unanimity on the superiority of numerical over analytical solutions for predicting infiltration mounds; the two methods have not been tested with observed field data. As a result, and to assist in discerning the best approach, analytical and numerical solutions were validated against results from three distinct field observations. The best match was noted between analytical and observed recharge mounds. In conclusion the practical applicability of each solution under various hydro-geologic conditions is summarized in the form of a table.