Steady-state evaporation from a water table has been extensively studied for both homogeneous and layered porous media. For layered media it is of interest to find an equivalent homogeneous medium and define "effective" hydraulic properties. In this paper a new solution for steady-state evaporation from coarse-textured porous media is presented. Based on this solution, the evaporation rate represents a macroscopic (column-scale) measure of unsaturated hydraulic conductivity at the pressure head equal to the maximum extent of the hydraulically connected region above the water table. The presented approach offers an alternative method for determination of unsaturated hydraulic conductivity of homogeneous coarse-textured soils and a new solution for prediction of the effective unsaturated hydraulic conductivity of layered coarse-textured soils. The solution was evaluated with both experimental data and numerical simulations. Comparison with experimental data and numerical results for hypothetically layered soil profiles demonstrate the applicability of the proposed approach for coarse-textured soils.
Bibliographical noteFunding Information:
The authors gratefully acknowledge support from the USDA NIFA AFRI Soil Processes Program under award 2009-65107-05835 and by the Utah Agricultural Experiment Station, Utah State University, Logan, Utah 84322-4810, approved as journal paper no 8722.
- Effective hydraulic properties
- Steady-state evaporation
- Unsaturated hydraulic conductivity