Direct measurement of the soil water retention curve using X-ray absorption
- Institute of Environmental Physics, INF 229, University of Heidelberg, D-69120 Heidelberg, Germany
- E-mail for corresponding author: email@example.com
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