Effect of velocity and water content on the gas-phase partitioning tracer test for the in-situ measurement of soil-water content in a large weighing lysimeter
AuthorCarlson, Tyson David
AdvisorBrusseau, Mark L.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractThis thesis describes research conducted to evaluate the efficacy of the gas-phase partitioning tracer method for measuring bulk soil-water content. A series of tracer experiments were conducted at two velocities and water contents in a well instrumented weighing lysimeter. The method is based on introducing gas-phase conservative and water-partitioning tracers into the system. The partitioning tracer dissolves into the water, which retards its movement with respect to a non-partitioning tracer. This retardation is a function of the soil-water content. The soil-water contents estimated from comparative moment analyses of the measured breakthrough curves were compared to values obtained using traditional methods for determining soil-water content. These methods include: neutron thermalization, time domain reflectometry, gravimetric core analysis, and soil tension. The results from the tracer test compare favorably at different velocities and soil-water contents with the data provided by traditional methods. For the slower velocities, the tracer results yielded soil-water contents of 0.06 and 0.12 while the traditional methods 'indicated soil-water contents of 0.06 and 0.15. Tracer tests conducted at higher velocities yielded soil-water contents of 0.05 and 0.11 while traditional methods indicated soil-water contents of 0.06 and 0.15. This indicates that the water partitioning tracer method has potential to provide accurate results under a variety of conditions.
Degree ProgramGraduate College
Hydrology and Water Resources