Vadose zone influences on aquifer parameter estimates of saturated-zone hydraulic theory

Aquifer drainage was numerically simulated by a coupled, unsaturated-saturated flow equation. The effect of the vadose zone on aquifer parameter predictions of classical hydraulic theory was investigated. Saturated-zone hydraulic theory was shown to be fairly robust in estimating the saturated hydraulic conductivity but less so in estimating drainable porosity, mainly because of the much tighter possible range for the latter. Application of the coupled flow equation may explain discrepancies between predictions of classical saturated-zone theory and observations.