Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.153
IF 5-year value: 5.460
IF 5-year
CiteScore value: 7.8
SNIP value: 1.623
IPP value: 4.91
SJR value: 2.092
Scimago H <br class='widget-line-break'>index value: 123
Scimago H
h5-index value: 65
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  17 Aug 2020

17 Aug 2020

Review status
This preprint is currently under review for the journal HESS.

Sigmoidal Water Retention Function with Improved Behavior in Dry and Wet Soils

Gerrit H. de Rooij1, Juliane Mai2, and Raneem Madi1,a Gerrit H. de Rooij et al.
  • 1Helmholtz Centre for Environmental Research – UFZ GmbH, Soil System Science Dept., Theodor-Lieser-Strasse 4, 06120 Halle (Saale), Germany
  • 2University of Waterloo, Dept. Civil and Environmental Engineering, 200 University Ave West, Waterloo, ON N2L 3G1, Canada
  • acurrent address: GFI Grundwasser-Consulting-Institut GmbH, Meraner Strasse 10, 01217 Dresden, Germany

Abstract. A popular parameterized soil water retention curve (SWRC) has a hydraulic conductivity curve associated with it that can have an infinite slope at saturation. The problem was eliminated before by giving the SWRC a non–zero air–entry value. This improved version still has an asymptote at the dry end, which limits its usefulness for dry conditions and causes its integral to diverge for commonly occurring parameter values. We therefore joined the parameterizations' sigmoid mid–section to a logarithmic dry section ending at zero water content for a finite matric potential, as was done previously for a power–law type SWRC. We selected five SWRC parameterizations that had been proven to produce unproblematic near–saturation conductivities and fitted these and our new curve to data from 21 soils. The logarithmic dry branch gave more realistic extrapolations into the dry end of both the retention and the conductivity curves than an asymptotic dry branch. We tested the original curve, its first improvement, and our second improvement by feeding them into a numerical model that calculated evapotranspiration and deep drainage for nine combinations of soils and climates. The new curve was more robust than the other two. The new curve was better able to produce a conductivity curve with a substantial drop during the early stages of drying than the earlier improvement. It therefore generated smaller amounts of more evenly distributed deep drainage compared to the spiked response to rainfall produced by the earlier improvement.

Gerrit H. de Rooij et al.

Interactive discussion

Status: open (until 12 Oct 2020)
Status: open (until 12 Oct 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Gerrit H. de Rooij et al.

Gerrit H. de Rooij et al.


Total article views: 164 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
122 41 1 164 20 1 4
  • HTML: 122
  • PDF: 41
  • XML: 1
  • Total: 164
  • Supplement: 20
  • BibTeX: 1
  • EndNote: 4
Views and downloads (calculated since 17 Aug 2020)
Cumulative views and downloads (calculated since 17 Aug 2020)

Viewed (geographical distribution)

Total article views: 150 (including HTML, PDF, and XML) Thereof 150 with geography defined and 0 with unknown origin.
Country # Views %
  • 1



No saved metrics found.


No discussed metrics found.
Latest update: 28 Sep 2020
Publications Copernicus
Short summary
The way soils capture infiltrating water affects crops and natural vegetation as well as groundwater recharge. This retention of soil water is captured by a mathematical function that covers all water contents from very dry to water-saturated. We combined two existing lines of research to improve the behaviour of a popular function for very dry and very wet conditions. Our new function could handle a wider range of conditions than earlier curves. We provide fits to a wide range of soils.
The way soils capture infiltrating water affects crops and natural vegetation as well as...