This paper on "Consequences of a Vanishing Diffusion Process in the Drainage from a One Dimensional Sand Column" was presented at the NAFEMS World Congress on Design, Simulation & Optimisation: Reliability & Applicability of Computational Methods - 9-11 April 1997, Stuttgart, Germany.

Abstract

A model for simulating water flow and air flow in unsaturated soils is presented. The drainage from a one dimensional soil column has been dealt with. The mathematical analysis of the equations has revealed that, due to a vanishing diffusion process, the gradient of the water degree of saturation is infinite at the water table. Moreover this discontinuity propagates with a velocity corroborating a local non linear equation which only involves the properties of the material. A numerical simulation of this problem confirmed these results.