The effect of heterogeneity on the agreement between analytical and numerical solutions describing the recession flow in unconfined hillslope aquifers

Analytical approximations or linearized versions of the Boussinesq equation, describing recession flow in unconfined hillslope aquifers have been applied extensively in the past. One of the major assumptions in the conceptual formulation is isotropic homogeneity of the aquifer. Notwithstanding the effect of aquifer heterogeneity on recession flow has been pointed out [1], only recent studies are increasingly focusing on the quantification of this effect [2,3]. In the present research, the relevance of heterogeneity is being studied by analyzing the agreement between analytical approximations and the numerical solution of the receding flow in a layered unconfined aquifer with different domain configurations (horizontal, inclined and concave impervious bedrock). For the application of the analytical approximations use is made of the equivalent hydraulic conductivity concept.