Articles | Volume 8, issue 1
https://doi.org/10.5194/hess-8-2-2004
© Author(s) 2004. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.Special issue:
29 Feb 2004
29 Feb 2004
Direct measurement of the soil water retention curve using X-ray absorption
Abstract. X-ray absorption measurements have been explored as a fast experimental approach to determine soil hydraulic properties and to study rapid dynamic processes. As examples, the pressure-saturation relation θ(Ψ) for a uniform sand column has been considered as has capillary rise in an initially dry sintered glass column. The θ(Ψ)-relation is in reasonable agreement with that obtained by inverting a traditional multi-step outflow experiment. Monitoring the initial phase of capillary rise reveals behaviour that deviates qualitatively from the single-phase, local-equilibrium regime described by Richards’ equation.
Keywords: X-ray absorption, soil hydraulic properties, soil water dynamics, Richards’ equation