Interaction of stream and sloping aquifer receiving constant recharge

An analytical solution and finite-element numerical solution of a linearize d and nonlinear Boussinesq equation, respectively, were obtained to describ e water table variation in a semi-infinite sloping/horizontal aquifer cause d by the sudden rise or fall of the water level in the adjoining stream. Tr ansient water table profiles in recharging and discharging aquifers having 0, 5, and 10% slopes and receiving zero or constant replenishment from the land surface were computed for t = 1 and 5 days by employing analytical and finite-element numerical solutions. The effect of linearization of the non linear governing equation, recharge, and slope of the impermeable barrier o n water table variation in a semi-infinite flow region was illustrated with the help of a numerical example. Results suggest that linearization of the nonlinear equation has only a marginal impact on the predicted water table heights (with or without considering constant replenishment). The relative errors between the analytical and finite-element numerical solution varied in the range of -0.39 to 1.59%. An increase in slope of the impermeable ba rrier causes an increase in the water table height at all the horizontal lo cations, except at the boundaries for the recharging case and a decrease fo r the discharging case.