| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Landscape and Environmental Research Group, Univ. of Amsterdam, Nieuwe Prinsengracht 130, 1018 VZ Amsterdam, the Netherlands
*Corresponding author (jf{at}fgb.frw.uva.nl).
ABSTRACT
Modeling of gas and vapor transport in soils requires knowledge of the relative gas diffusion coefficient. The relative diffusion coefficient was determined as a function of air-filled porosity, using a pore model based on two tortuous tubes of different radii joined in series. This model was fitted to measured relative diffusion coefficients on undisturbed samples of nine soil types at a wide range of water contents. It was found that model parameters vary with the soil types studied. Combined measurements of the water retention curve, air-filled porosity, and relative diffusion coefficient were made to evaluate the effects of water distribution in the soil pores on the relative diffusion coefficient. After the samples were saturated with water, the residual air-filled porosity ranged from 0.051 to 0.167 m3 m–3 and the relative diffusion coefficient was practically zero, which is due to pore blocking by soil water. At pressure heads corresponding to the air-entry value in the water retention function, air-filled porosity ranged from 0.095 to 0.256 m3 m–3 and the relative diffusion coefficient ranged from 0.002 to 0.013. From this point, with increasing air-filled porosity, the relative diffusion coefficient increased rapidly to values ranging from 0.165 to 0.383 at zero water content. It was concluded that the air-entry value is an important parameter, which indicates a priori the water content at which pore blocking becomes relevant.
Received for publication August 2, 1993.
This article has been cited by other articles:
|
|
 |
|
  A. C. Resurreccion, P. Moldrup, K. Kawamoto, S. Yoshikawa, D. E. Rolston, and T. Komatsu Variable Pore Connectivity Factor Model for Gas Diffusivity in Unsaturated, Aggregated Soil Vadose Zone J., April 14, 2008; 7(2): 397 - 405. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Moldrup, T. Olesen, S. Yoshikawa, T. Komatsu, and D. E. Rolston Three-Porosity Model for Predicting the Gas Diffusion Coefficient in Undisturbed Soil Soil Sci. Soc. Am. J., May 1, 2004; 68(3): 750 - 759. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Caron and N. V. Nkongolo Assessing Gas Diffusion Coefficients in Growing Media from in situ Water Flow and Storage Measurements Vadose Zone J., February 1, 2004; 3(1): 300 - 311. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. H. Weerts, D. Kandhai, W. Bouten, and P. M. A. Sloot Tortuosity of an Unsaturated Sandy Soil Estimated using Gas Diffusion and Bulk Soil Electrical Conductivity: Comparing Analogy-based Models and Lattice-Boltzmann Simulations Soil Sci. Soc. Am. J., November 1, 2001; 65(6): 1577 - 1584. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. Pedersen, S. O. Petersen, and F. P. Vinther Stochastic Diffusion Model for Estimating Trace Gas Emissions with Static Chambers Soil Sci. Soc. Am. J., January 1, 2001; 65(1): 49 - 58. [Abstract] [Full Text]
|
|
|
|
|
|
A. H. Weerts, J. I. Freijer, and W. Bouten Modeling the Gas Diffusion Coefficient in Analogy to Electrical Conductivity Using a Capillary Model Soil Sci. Soc. Am. J., March 1, 2000; 64(2): 527 - 532. [Abstract] [Full Text]
|
|
|
|
|
|
P. Moldrup, T. Olesen, P. Schjønning, T. Yamaguchi, and D.E. Rolston Predicting the Gas Diffusion Coefficient in Undisturbed Soil from Soil Water Characteristics Soil Sci. Soc. Am. J., January 1, 2000; 64(1): 94 - 100. [Abstract] [Full Text]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Vadose Zone Journal | Journal of Plant Registrations | ||||
| Journal of Natural Resources and Life Sciences Education |
Journal of Environmental Quality |
||||
