|San Jose Martinez, Fernando|
Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 9/24/2007
Publication Date: 12/14/2007
Citation: Martin, M.A., Tuller, M., Guber, A.K., Guttierez-Garcia, C., San Jose Martinez, F., Pachepsky, Y.A., Caniego, J. 2007. Pore space statistics from the X-ray CT of large undisturbed soil columns [abstract]. Fall Meeting of the American Geophyscial Union, December 10-14, 2007, San Francisco, CA. H53G-1707. Interpretive Summary:
Technical Abstract: 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 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.