Wednesday, May 1, 2013: 8:00 a.m.
Regency West 6 (Hyatt Regency San Antonio)
James J. Butler, Ph.D., University of Kansas
Geoffrey C. Bohling, University of Kansas
Edward C. Reboulet, University of Kansas
Josh Olson, University of Kansas
Hydrologists have long recognized that changes in barometric pressure can produce changes in water levels in wells. Although water-level responses to barometric pressure are typically viewed as noise that must be removed prior to, for example, pumping-test analyses, these responses should be viewed as a signal that provides important information about subsurface conditions. The barometric response function (BRF) is a useful time-domain tool for characterizing the relationship between barometric pressure and water levels; this function can be determined from water-level and barometric-pressure data using a regression convolution procedure that is implemented in an Excel-based program downloadable from the Kansas Geological Survey (KGS) website. The interpretation of BRFs will be the major focus of this presentation. The BRF from a well in a confined aquifer can include information about the hydraulic connection between the well and the aquifer, the aquifer storage parameter, the degree of aquifer confinement, and the viability/existence of an annular seal across the overlying confining unit. The BRF from a well in an unconfined aquifer can provide information about the hydraulic connection between the well and the aquifer and the pneumatic diffusivity of the overlying vadose zone. In both cases, changes in the BRF over time can provide information about changing conditions in the well (e.g., screen clogging that reduces the hydraulic connection) and the vadose zone (e.g., changes in moisture conditions). We will demonstrate the power of the BRF and the information it can provide using field data from a series of KGS monitoring sites in the High Plains aquifer in western Kansas.
| James J. Butler, Ph.D.
, University of Kansas
|
|
|
Jim Butler is a Senior Scientist and Chief of the Geohydrology Section of the Kansas Geological Survey at the University of Kansas. He holds a B.S. in Geology from the College of William and Mary, and an M.S. and Ph.D in Applied Hydrogeology from Stanford University. His current research interests include high-resolution subsurface characterization, well responses to natural stimuli, and the role of phreatophytes in stream-aquifer systems. Butler was the 2007 Darcy Distinguished Lecturer of the National Ground Water Association.
|
| Geoffrey C. Bohling
, University of Kansas
|
|
|
Geoff Bohling is an Associate Scientist in the Geohydrology Section of the Kansas Geological Survey at the University of Kansas. He holds a B.A. in English and a B.S. in Geophysics from the University of Kansas, an M.S. in Geology from the University of Wisconsin-Madison, and a Ph.D. in Geology from the University of Kansas. His research involves application of geostatistical techniques and inverse procedures to aquifer characterization problems at field and regional scales. His current projects involve analysis of high-resolution direct-push hydraulic data, and development of quantitative aquifer models from qualitative drillers’ log data.
|
| Edward C. Reboulet
, University of Kansas
|
|
|
Ed Reboulet is a Senior Research Assistant in the Geohydrology Section of the Kansas Geological Survey at the University of Kansas. He holds a B.S. in Geology from Wright State University and a M.S. in Geology from Boise State University. His current research interests include development of field methods for applied hydrogeology and new applications of direct-push technology for subsurface characterization.
|
| Josh Olson
, University of Kansas
|
|
|
Josh Olson is currently pursuing a B.S. in Hydrogeology at the University of Wisconsin – Eau Claire. He is interested in the development of clean water sources in underprivileged communities and is presently assisting a UW-Eau Claire professor with Kenyan water projects. In the summer of 2012, he was a participant in the Applied Geohydrology Summer Research Assistantship program of the Kansas Geological Survey. This program is open to students at any university with an interest in learning more about recent developments in hydrogeological field methods.
|
