Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 17, 611-618, 2013
https://doi.org/10.5194/hess-17-611-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
11 Feb 2013
Identifying a parameterisation of the soil water retention curve from on-ground GPR measurements
A. Dagenbach, J. S. Buchner, P. Klenk, and K. Roth Institute of Environmental Physics, Heidelberg University, Heidelberg, Germany
Abstract. We show the potential of on-ground Ground-Penetrating Radar (GPR) to identify the parameterisation of the soil water retention curve, i.e. its functional form, with a semi-quantitative analysis based on numerical simulations of the radar signal. An imbibition and drainage experiment has been conducted at the ASSESS-GPR site to establish a fluctuating water table, while an on-ground GPR antenna recorded traces over time at a fixed location. These measurements allow to identify and track the capillary fringe in the soil. The typical dynamics of soil water content with a transient water table can be deduced from the recorded radargrams. The characteristic reflections from the capillary fringes in model soils that are described by commonly used hydraulic parameterisations are investigated by numerical simulations. The parameterisations used are (i) full van Genuchten, (ii) simplified van Genuchten with m = 1 − 1/n and (iii) Brooks–Corey. All three yield characteristically different reflections, which allows the identification of an appropriate parameterisation by comparing to the measured signals. We show that for the sand used here, these signals are not consistent with the commonly used simplified van Genuchten parameterisation with m = 1 − 1/n.

Citation: Dagenbach, A., Buchner, J. S., Klenk, P., and Roth, K.: Identifying a parameterisation of the soil water retention curve from on-ground GPR measurements, Hydrol. Earth Syst. Sci., 17, 611-618, https://doi.org/10.5194/hess-17-611-2013, 2013.
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