Published online 6 May 2005
Published in Soil Sci Soc Am J 69:807-815 (2005)
DOI: 10.2136/sssaj2004.0191
© 2005 Soil Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
A Laboratory Method for Determining the Unsaturated Hydraulic Properties of Soil Peds
Darren G. Meadowsa,b,*,
Michael H. Younga and
Eric V. McDonaldc
a Desert Research Institute, Univ. and Community College System of Nevada, Las Vegas, NV 89119
b Hydrologic Sciences Program, Univ. of Nevada, Reno, NV 89532
c Desert Research Institute, Univ. and Community College System of Nevada, Reno, NV 89512

View larger version (196K):
[in a new window]
|
Fig. 1. Photograph of the excavated soil from underneath the tension infiltrometer. Individual soil peds are clearly delineated. In the field, these soil peds were connected and part of a contiguous desert pavement surface. Once removed from the support of surrounding peds, they slumped to the position seen in this figure. Ring is 20 cm in diameter.
|
|

View larger version (132K):
[in a new window]
|
Fig. 2. Photograph of the experimental setup.
|
|

View larger version (49K):
[in a new window]
|
Fig. 3. Digitally reconstructed image of area underneath tension disc infiltrometer. Figure delineates individual peds and displays the respective values of Ks as determined from permeameter inversion. Units are cm d1. Figure also shows the location of the 20-cm diam. tension disc.
|
|

View larger version (47K):
[in a new window]
|
Fig. 4. Digitally reconstructed image of area underneath tension disc infiltrometer and representation of van Genuchten's parameter. Units are cm1. Figure also shows the location of the 20-cm diam. tension disc.
|
|

View larger version (47K):
[in a new window]
|
Fig. 5. Digitally reconstructed image of area underneath tension disc infiltrometer and representation of van Genuchten's n parameter.
|
|

View larger version (26K):
[in a new window]
|
Fig. 6. (A) Water retention curves and (B) hydraulic conductivity functions using parameter values found in C. Solid lines are produced from values obtained from the field infiltrometer test; dashed lines are produced from the areally weighted mean parameters of the individual peds. Note that the solid lines are from a sorption experiment, whereas the dashed lines are from a desorption experiment.
|
|
Copyright © 2005 by the Soil Science Society of America.