Effect of hydraulic conductivity probability distribution function on simulated solute leaching

In this paper, the effect of fitting several different probability-distribution functions to hydraulic conductivity or pore-water velocity values, in the simulation of the movement of a noncreative solute through the soil, is evaluated. The simulation of solute transport in the soil was found to be sensitive to the distribution fitted to pore-water velocity. The log-Gaussian (log-normal) distribution, though traditionally used, is not necessarily the best distribution for characterizing the spatial variability of saturated hydraulic conductivity, pore-water velocity, or infiltrability. The upper tails of the simulated relative concentration series are best fitted by beta distributions, regardless of the input distribution used for pore-water velocity.