HR: 0830h
AN: H21D-0857    [PDF]
TI: A New Approach to Measuring the Direction of Horizontal Groundwater Flow
AU: * Klammler, H
EM: haki@gmx.at
AF: Department of Civil and Coastal Engineering, University of Florida, Gainesville, FL 32611 United States
AU: Hatfield, K
EM: khatf@ce.ufl.edu
AF: Department of Civil and Coastal Engineering, University of Florida, Gainesville, FL 32611 United States
AU: Annable, M
EM: annable@ufl.edu
AF: Department of Environmental Engineering Sciences, University of Florida, Gainesville, Fl 32611 United States
AB: A Passive Flux Meter (PFM) has been developed to simultaneously measure the magnitudes of groundwater and contaminant fluxes in porous media. The PFM consists of a permeable sorptive media in the shape of a homogeneous cylinder that is inserted into a borehole and that exactly fits the diameter of the well screen. The PFM, which initially contains a known amount of a resident tracer, thus intercepts groundwater and contaminant flow causing the partial elution of the resident tracer from the PFM and the sorption of contaminants onto the PFM. Quantitative analysis of the PFM for the amount of resident tracer remaining on the PFM media and the amount of contaminant sorbed onto the PFM after exposure to groundwater and contaminant flow allows for the determination of the magnitudes of groundwater and contaminant fluxes. In this work, two modified configurations of the PFM are presented and compared that are capable of measuring the horizontal flow direction simultaneously to the magnitudes of groundwater and contaminant fluxes. The first configuration is characterized by a simple separate analysis of various sub areas within the circular cross section of the PFM. Thus, the flow direction can be measured by identifying the direction of the movement of the resident tracer across the cross section. The second configuration makes use of different directional tracers in three sectors of the circular cross section of the PFM. A single analysis of the whole cross section determines the mass of each directional tracer remaining in the PFM, which allows for an estimation of the flow direction. For both configurations a geometric approach is used to derive the relationships between the measured tracer masses and the flow direction. Tracer and contaminant sorption is assumed linear, instantaneous and reversible, and dispersive transport is neglected. The solutions obtained for both configurations are used to evaluate and compare the two alternatives regarding their theoretical potential to measure flow direction. Some practical aspects concerning the differences between the two modified configurations are discussed and first results of laboratory tests configuration are presented.
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2003 Fall Meeting