EFFECT OF HYDRAULIC CONDUCTIVITY PROBABILITY-DISTRIBUTION FUNCTION ONSIMULATED SOLUTE LEACHING

In this paper, the effect of fitting several different probability-dis tribution functions to hydraulic conductivity or pore-water velocity v alues, in the simulation of the movement of a nonreactive solute throu gh the soil, is evaluated. The simulation of solute transport in the s oil was found to be sensitive to the distribution fitted to pore-water velocity. The log-Gaussian (log-normal) distribution, though traditio nally used, is not necessarily the best distribution for characterizin g the spatial variability of saturated hydraulic conductivity, pore-wa ter velocity, or infiltrability. The upper tails of the simulated rela tive concentration series are best fitted by beta distributions, regar dless of the input distribution used for pore-water velocity.