Articles | Volume 10, issue 6
Hydrol. Earth Syst. Sci., 10, 817–827, 2006
https://doi.org/10.5194/hess-10-817-2006
Hydrol. Earth Syst. Sci., 10, 817–827, 2006
https://doi.org/10.5194/hess-10-817-2006

  09 Nov 2006

09 Nov 2006

Novel evaporation experiment to determine soil hydraulic properties

K. Schneider1, O. Ippisch2,*, and K. Roth1 K. Schneider et al.
  • 1Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany
  • 2Institute of Parallel and Distributed Systems, University of Stuttgart, Stuttgart, Germany
  • *formerly: Interdisciplinary Center for Scientific Computing, University of Heidelberg, Germany

Abstract. A novel experimental approach to determine soil hydraulic material properties for the dry and very dry range is presented. Evaporation from the surface of a soil column is controlled by a constant flux of preconditioned air and the resulting vapour flux is measured by infrared absorption spectroscopy. The data are inverted under the assumptions that (i) the simultaneous movement of water in the liquid and vapour is represented by Richards' equation with an effective hydraulic conductivity and that (ii) the coupling between the soil and the well-mixed atmosphere can be modelled by a boundary layer with a constant transfer resistance. The optimised model fits the data exceptionally well. Remaining deviations during the initial phase of an experiment are thought to be well-understood and are attributed to the onset of the heat flow through the column which compensates the latent heat of evaporation.

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