Pore Space Statistics From the X-ray CT of Large Undisturbed Soil Columns

HR: 1340h
AN: H53G-1507 [Abstracts]
TI: Pore Space Statistics From the X-ray CT of Large Undisturbed Soil Columns
AU: Martin, M A
EM: miguelangel.martin@upm.es
AF: E.T.S.I. Agrónomos Technical University of Madrid, Avd. de la Complutense, Madrid, 28040, Spain
AU: Tuller, M
EM: mtuller@cals.arizona.edu
AF: Dept of Soil, Water and Environmental Science, College of Agriculture, University of Arizona, Tucson, AZ 85721, United States
AU: Guber, A K
EM: Andrey.Guber@ars.usda.gov
AF: USDA-ARS Beltsville Agricultural Research Center, 10300 Baltimore Ave. Bldg. 173 BARC-East, Beltsville, MD 20705, United States
AU: García-Gutiérrez, C
EM: boneiro@gmail.com
AF: E.T.S.I. Agrónomos Technical University of Madrid, Avd. de la Complutense, Madrid, 28040, Spain
AU: San Jose Martinez, F
EM: fernando.sanjose@upm.es
AF: E.T.S.I. Agrónomos Technical University of Madrid, Avd. de la Complutense, Madrid, 28040, Spain
AU: * Pachepsky, Y A
EM: Yakov. Pachepsky@ars.usda.gov
AF: USDA-ARS Beltsville Agricultural Research Center, 10300 Baltimore Ave. Bldg. 173 BARC-East, Beltsville, MD 20705, United States
AU: Caniego, J F
EM: javier.caniego@upm.es
AF: E.T.S.I. Agrónomos Technical University of Madrid, Avd. de la Complutense, Madrid, 28040, Spain
AB: Large soil columns need to be studied to infer geometric properties of macropores and their role in flow and transport phenomena, especially when colloid or colloid-facilitated transport is of interest. We have sampled and studied undisturbed columns (7.5 cm ID, 20 cm length) of the Taylor soil from a grassed floodplain. A FlashCTTM - 420 kV system (HYTEC Inc.) was used for X-ray computer tomography (CT) scanning. The FlashCT-DAQ, the FlashCT-DPS, and the FlashCT-VIZ software was used for reconstruction. A MatLab® software with GUI for processing, analyzing and visualizing of 3D X-ray CT scans was developed. It was used in the binarization process on each of 1480 cross-section images obtained for each column. The resolution of about 100 mkm was sufficient to distinguish macropores. The high-connectivity macropore space was reconstructed from the imagery, as well. The "porosity-depth" data series have been investigated. The R/S (rescale range) analysis indicated that these series did not have a simple structure that might be understood as a persistent or antipersistent fractional Brownian motion using the Hurst exponent. More complex behavior had been detected that could be characterized by means of multifractal analysis. The water retention data were obtained for column sections and were related to the CT characterization of these sections. Large columns present feasible objects for CT if macroporosity is of interest.
DE: 0486 Soils/pedology (1865)
DE: 1894 Instruments and techniques: modeling
DE: 3225 Numerical approximations and analysis (4260)
DE: 4440 Fractals and multifractals
SC: Hydrology [H]
MN: 2007 Fall Meeting