A simple approach to predicting unsaturated hydraulic conductivity based on empirically scaled microscopic characteristic length

AbstractA simple and empirical scaling approach is proposed for predicting the unsaturated hydraulic conductivity (Kus) based on the microscopic characteristic length (λ). The approach was tested on 19 different soils. The results showed that the proposed approach was useful for a wide range of soil water content, except at relatively high soil moisture. The predicted λ(θ) values were overestimated by 2%, which led to 5% overestimation in prediction of Kus(θ) at soil matric potentials of less than –0.1 MPa. However, the predictions of Kus(θ) were not satisfactory at soil matric potentials of greater than –0.1 MPa. The results also revealed that the proposed approach was accurate for predicting Kus(θ) in the dry range of soil water content. Future models should be developed based on the empirical and physical scaling approaches to improve prediction of soil hydraulic properties at high water contents. This means that new scaling factors need to incorporate more information about the pore geometry.Editor D....