Unsteady groundwater flow on sloping bedrock

Abstract

A numerical model based on the equation describing the unsteady groundwater flow on impervious sloping bedrock has been herewith formulated. The case which has been studied concerns the groundwater flow from one canal to another with a sudden rising of the canal level as an upstream boundary condition, while the downstream level remains constant. Initially, at time t = 0, both levels are equal. The numerical model uses the finite element technique with Galerkin's method. The stability and accuracy of the method have been proven by comparison of numerical results with the Crank‐Nicolson scheme. The algorithm developed for the finite element technique gives the same results as the one for the finite difference scheme. The effect of inclination of lower impervious boundary on outflow rate has been studied.