HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Cassel, D. K. Articles by Biggar, J. W. Search for Related Content PubMed Articles by Cassel, D. K. Articles by Biggar, J. W. Agricola Articles by Cassel, D. K. Articles by Biggar, J. W.

Soil-Water Movement in Response to Imposed Temperature Gradients¹

ABSTRACT

Redistribution of soil water within insulated, uniformly packed, horizontal samples of unsaturated Columbia fine sandy loam at several soil-water contents was studied in response to imposed temperature gradients ranging from 0.5 to 1.0C/cm. Soil bulk density and initial, transient, and final soil-water-content distributions were determined each 0.5-cm along the column by gamma-radiation attenuation. Initial, transient, and final soil temperature distributions were monitored by glass-encased thermistors at 2-cm intervals—both at the center and 0.3 cm from the column wall. Apparent thermal and isothermal soil-water diffusivity values were calculated using transient water content data. The observed net water flux was found to increase with decreasing water content throughout the 0.077–0.274 cm³/cm³ range. For Columbia soil at 0.077 cm³/cm³ the observed mean net water flux across 1-cm sections of the soil showed acceptable agreement with that predicted by the theory of Philip and deVries; Fick's law and the modified Taylor-Cary irreversible thermodynamic equation both underpredicted the observed fluxes.

Contribution from the Department of Water Science & Engineering, University of California, Davis. This investigation was partially supported by funds received from the Water Resources Center, University of California, and from the US Army Electronics Research and Development Activity, Ft. Huachuca, Ariz., under Grant no. DAAB G29-07-67-C00034.

² Laboratory Technician, Professor and Associate Professor of Water Science. The senior author is now Associate Professor of Soil Physics, Department of Soils, North Dakota State University, Fargo.

Received for publication October 28, 1968. Accepted for publication February 24, 1968.