HR: 0800h
AN: H21C-1356    [Abstracts]
TI: Gas-Phase Diffusive Tracer Test for the In-situ Measurement of Tortuosity in the Vadose Zone
AU: * Tick, G R
EM: gtick@geo.ua.edu
AF: The University of Alabama, The Department of Geological Sciences Bevill Building Box 870338, Tuscaloosa, AL 35487-0338 United States
AU: Brusseau, M L
EM: brusseau@ag.arizona.edu
AF: The University of Arizona, The Department of Soil, Water, and Environmental Science 429 Shantz Building, Tucson, AZ 85721 United States
AU: Brusseau, M L
EM: brusseau@ag.arizona.edu
AF: The University of Arizona, The Department of Hydrology and Water Resources Harshbarger Building Box 210011, Tucson, AZ 85721 United States
AU: McColl, C M
EM: cmccoll@ag.arizona.edu
AF: The University of Arizona, The Department of Soil, Water, and Environmental Science 429 Shantz Building, Tucson, AZ 85721 United States
AU: Yolcubal, I
EM: yolcubal@hwr.arizona.edu
AF: Kocaeli University, Geological Engineering Department, Izmit, 41040 Turkey
AB: Robust measures of porous-medium tortuosity are one of the many components needed for accurate characterization and prediction of soil-moisture relationships, infiltration rates, and contaminant transport in the subsurface. For field-scale applications, tortuosities measured in-situ may be of greater utility than laboratory-measured values. A small-scale field study was conducted to evaluate the effectiveness of a gas-phase diffusive tracer test for the in-situ measurement of tortuosity. A single well was installed at the test site, and a non-reactive (sulfur hexafluoride; SF6) gas-phase tracer was injected into the screened interval of the well. Gas samples were collected from the injection point as the tracer diffused into the surrounding soil matrix. An analytical solution was calibrated to the measured profiles, producing fitted values for tortuosity. The values obtained from the tracer test were compared to values estimated with several widely-used correlations.
DE: 1838 Infiltration
DE: 1842 Irrigation
DE: 1865 Soils (0486)
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: Fall Meeting 2005