Accuracy of flowmeters measuring horizontal groundwater flow in an unconsolidated aquifer simulator.

Ground Water Monitoring and Remediation
By: , and 

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Abstract

Borehole flowmeters that measure horizontal flow velocity and direction of groundwater flow are being increasingly applied to a wide variety of environmental problems. This study was carried out to evaluate the measurement accuracy of several types of flowmeters in an unconsolidated aquifer simulator. Flowmeter response to hydraulic gradient, aquifer properties, and well-screen construction was measured during 2003 and 2005 at the U.S. Geological Survey Hydrologic Instrumentation Facility in Bay St. Louis, Mississippi. The flowmeters tested included a commercially available heat-pulse flowmeter, an acoustic Doppler flowmeter, a scanning colloidal borescope flowmeter, and a fluid-conductivity logging system. Results of the study indicated that at least one flowmeter was capable of measuring borehole flow velocity and direction in most simulated conditions. The mean error in direction measurements ranged from 15.1 degrees to 23.5 degrees and the directional accuracy of all tested flowmeters improved with increasing hydraulic gradient. The range of Darcy velocities examined in this study ranged 4.3 to 155 ft/d. For many plots comparing the simulated and measured Darcy velocity, the squared correlation coefficient (r2) exceeded 0.92. The accuracy of velocity measurements varied with well construction and velocity magnitude. The use of horizontal flowmeters in environmental studies appears promising but applications may require more than one type of flowmeter to span the range of conditions encountered in the field. Interpreting flowmeter data from field settings may be complicated by geologic heterogeneity, preferential flow, vertical flow, constricted screen openings, and nonoptimal screen orientation.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Accuracy of flowmeters measuring horizontal groundwater flow in an unconsolidated aquifer simulator.
Series title Ground Water Monitoring and Remediation
DOI 10.1111/j.1745-6592.2010.01324.x
Volume 31
Issue 2
Year Published 2011
Language English
Publisher Wiley
Publisher location Hoboken, NJ
Contributing office(s) Indiana Water Science Center
Description 15 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Ground Water Monitoring and Remediation
First page 48
Last page 62