Falling water tables in horizontal/sloping aquifer

To describe falling water tables between two drains lying on a horizontal/s loping impermeable barrier. analytical solutions of the Boussinesq equation linearized by Baumann's and Werner's methods and numerical solutions of th e nonlinear form of the Boussinesq equation using finite-difference and fin ite-element methods were obtained. A hybrid finite analytic method, in whic h the nonlinear Boussinesq equation was locally linearized and solved analy tically after approximating the unsteady term by a simple finite-difference formula to approximately preserve the overall nonlinear effect by the asse mbly of locally analytic solutions, was also used to obtain a solution of t he Boussinesq equation. Midpoints of falling water tables between two drain s in a horizontal/sloping aquifer as obtained from various solutions were c ompared with already existing experimental values. Euclidean L2 and Tchebyc heff L-infinity norms were used to rank the performance of various solution s with respect to experimental data. It was observed that the performance o f the hybrid finite analytic solution is the best, followed by finite eleme nt, finite difference, analytical with Werner's linearization method, and a nalytical with Baumann's linearization method, respectively.