Stochastic analysis of Richards equation under uncertainty in unsaturated soil parameters

In the present study, stochastic analysis of Richards equation is performed under uncertainty in unsaturated soil parameters. The deviations in means and standard deviations of stochastic and deterministic models are studied considering the saturated hydraulic conductivity and Van Genuchten soil parameter ‘n’ as random variables. It is shown that the randomness in saturated hydraulic conductivity has a pronounced effect on the deviation in the means of the stochastic and deterministic models whereas the randomness in parameter ‘n’ has little effect. It is also shown that the cross correlation between the saturated hydraulic conductivity and the parameter ‘n’ has little effect on the deviations in means of stochastic and deterministic models. However, the cross correlation has significantly reduced the deviations in standard deviation between the stochastic and deterministic models.