Investigation of the accuracy of numerical modelling of seepage through variably saturated soils

A numerical model is presented for the solution of flow in variably saturated porous media (single-phase, isothermal fluid flow), assuming continuity of flow between unsaturated and saturated soil zones. It allows for continuous variation of the hydraulic properties as a function of the pressure head using real soil data taken from relevant literature [12] and takes into account hydraulic property hysteresis. Numerical results compared with experimental results found in the literature [12], show the significant impact of ignoring hysteresis in numerical analyses of seepage. Moreover, a linear type model for hysteresis is shown to produce satisfactory results, despite its simplicity.