|
|
||||||||
a Dep. of Land, Air, and Water Resources, Univ. of California, Davis, CA 95616, USA
b Dep. of Environmental Engineering, Aalborg Univ., Sohngaardsholmsvej 57, DK-9000 Aalborg, Denmark
* Corresponding author (jwhopmans{at}ucdavis.edu)
Although soil structure and pore geometry characteristics largely control flow and transport processes in soils, there is a general lack of experiments that study the effects of soil structure and pore-space characteristics on air and water permeability. Our objective was to determine the dependency of soil permeability on fluid content for both water and air, and compare results for both disturbed (D) and undisturbed (UD) soils. For that purpose, we first measured the water permeability (kw) and air permeability (ka) for several intact UD soil samples. Subsequently, the same samples were crushed and repacked into the same soil cores to create the D equivalent for the same soil material. Measurements showed large differences between D and UD samples, confirming the enormous impact of soil structure and pore-space characteristics on flow. The permeability of both fluid phases (air and water) was greatly reduced for the D samples, especially for soil air permeability due to its greater dependency on soil aggregation and structure. Soil water retention and permeability data were fitted to Campbell's and Mualem's pore-size distribution model, respectively. Regardless of soil disturbance, we showed that the tortuosityconnectivity parameter, l, for the water permeability (l1) and air permeability (l2) were different. This is in contrast to the general practice of using the same parameter value for both functions. The relation between l1 and l2 was largely controlled by soil structure and associated macroporosity properties.
Abbreviations: D, disturbed UD, undisturbed
This article has been cited by other articles:
![]() |
E. Segal, S. A. Bradford, P. Shouse, N. Lazarovitch, and D. Corwin Integration of Hard and Soft Data to Characterize Field-Scale Hydraulic Properties for Flow and Transport Studies Vadose Zone J., August 1, 2008; 7(3): 878 - 889. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. F. Zhang, M. Oostrom, and A.L. Ward Saturation-Dependent Hydraulic Conductivity Anisotropy for Multifluid Systems in Porous Media Vadose Zone J., November 20, 2007; 6(4): 925 - 934. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J.M. Smucker and J. W. Hopmans Preface: Soil Biophysical Contributions to Hydrological Processes in the Vadose Zone Vadose Zone J., May 17, 2007; 6(2): 267 - 268. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kawamoto, P. Moldrup, P. Schjonning, B. V. Iversen, T. Komatsu, and D. E. Rolston Gas Transport Parameters in the Vadose Zone: Development and Tests of Power-Law Models for Air Permeability Vadose Zone J., November 20, 2006; 5(4): 1205 - 1215. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||