Field Study of Hydraulic Conductivity in a Heterogeneous Aquifer: Comparison of Single-Borehole Measurements Using Different Instruments

Authors

Vitaly A. Zlotnik, University of Nebraska-LincolnFollow
Brian R. Zurbuchen, Nebraska Department of Environmental Quality

Document Type

Article

Date of this Version

4-2003

Comments

Published in Water Resources Research (April 2003) 39(4): 1,101-1,112. DOI:10.1029/2002WR001415. Copyright 2003, the American Geophysical Union. Used by permission.

Abstract

This field study compares three techniques for estimating the vertical distribution of horizontal hydraulic conductivity K_r in a heterogeneous aquifer and evaluates possible support volume effects. The dipole flow test (DFT), multilevel slug test (MLST), and borehole flowmeter test (BFT) are based on different kinematic flow structures and the shape and the size of the support volumes. The experiment design employed an identical characteristic linear scale for all tests. Vertical profiles of K_r ranging up to 260 m/day from tested wells in an alluvial aquifer exhibit a strong correlation in spite of the differences between test hydraulics. Results suggest that tested screen length is an important indicator of the averaging mechanism for hydraulic tests. Correlation between the DFT and MLST is especially strong. Correlation between data from the BFT and other tests is not as strong due to the absence of a distinct physical vertical scale, among other factors. The differences between the tests are discussed using the concept of a weighting function associated with the magnitude of instantaneous local velocity.