On the effective hydraulic conductivity in mean vertical unsaturated steady flows

We investigate effects of the heterogeneity formation properties as well as the mean head on the structure of κ∗. Overall, results suggest that, given the formation statistics, the impact of the heterogeneity upon κ∗ is enhanced as the medium becomes drier. This is particularly so when the variability of the fluctuation of Y = ln Ks is small compared with that of ζ = ln α. Conversely, when the heterogeneity of Y is prevalent upon that of ζ, κ∗ is influenced solely by the anisotropic structure of the formation unless the horizontal correlation scales are much greater than the vertical ones.