|
|
||||||||
a Desert Research Institute, Univ. and Community College System of Nevada, Las Vegas, NV 89119
b Desert Research Institute, Univ. and Community College System of Nevada, Reno, NV 89512
c Currently, Hydrologic Sciences Program, Univ. of Nevada, Reno, NV 89532
d Currently, Dep. of Geosciences, Boise State Univ., Boise, ID 83725
* Corresponding author (michael.young{at}dri.edu)
Received 2 November 2003.
Desert pavements are prominent features in arid environments and consist of a surface layer of closely packed gravel that overlies a thin, gravel-poor, vesicular A (Av) soil horizon. Well-developed Av horizons form distinct and highly structured columnar peds. These structures, along with their silt- and clay-rich texture, are hypothesized as controlling infiltration and hence the overall hydrologic conditions in the soil profile. The objectives of this study were to (i) evaluate how pedological development in near-surface soil horizons in an arid alluvial fan complex affects the soil hydraulic characteristics, and (ii) to compare the use of Wooding's equation and inverse modeling for evaluating hydraulic conductivity in highly layered, near-surface soils. These objectives were approached through field tension infiltrometer studies, soil sampling, and laboratory analyses of soil texture, water content, and soluble salt concentrations. Soils at five sites were studied at the Mojave National Preserve, California, representing a soil chronosequence (50100000 yr) with varying degrees of desert pavement development. Results indicated 100-fold and threefold declines, respectively, in saturated hydraulic conductivity (Ks) with both analytical methods, and
w using Wooding's method, as the soils aged. No clear trends in Ks or
w were detected in the underlying horizon, indicating that the controlling feature at these sites, in terms of water entry, was the Ks of the surface (Av) horizon. Soluble salt concentrations within the profile indicated reduced infiltration with increased pavement development. Results showed that surface age can be used as an excellent predictor of saturated hydraulic conductivity (r2 = 0.9254). Further, results suggest that Av horizon development represents a key process controlling water cycling, potentially influencing ecosystem function in arid lands.
This article has been cited by other articles:
![]() |
R. C. Graham, D. R. Hirmas, Y. A. Wood, and C. Amrhein Large near-surface nitrate pools in soils capped by desert pavement in the Mojave Desert, California Geology, March 1, 2008; 36(3): 259 - 262. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Pelletier Cantor set model of eolian dust deposits on desert alluvial fan terraces Geology, May 1, 2007; 35(5): 439 - 442. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Zhu, M. H. Young, and M. Th. van Genuchten Upscaling Schemes and Relationships for the Gardner and van Genuchten Hydraulic Functions for Heterogeneous Soils Vadose Zone J., February 27, 2007; 6(1): 186 - 195. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. B. Ramos, M. C. Goncalves, J. C. Martins, M. Th. van Genuchten, and F. P. Pires Estimation of Soil Hydraulic Properties from Numerical Inversion of Tension Disk Infiltrometer Data Vadose Zone J., May 26, 2006; 5(2): 684 - 696. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Meadows, M. H. Young, and E. V. McDonald Estimating the Fine Soil Fraction of Desert Pavements Using Ground Penetrating Radar Vadose Zone J., May 26, 2006; 5(2): 720 - 730. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Meadows, M. H. Young, and E. V. McDonald A Laboratory Method for Determining the Unsaturated Hydraulic Properties of Soil Peds Soil Sci. Soc. Am. J., May 6, 2005; 69(3): 807 - 815. [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 |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||