Greg Koltun
Greg is an Emeritus Hydrologist and surface-water specialist for the Ohio-Kentucky-Indiana Water Science Center.
He received a B.S. in microbiology and an M.S. in civil engineering from the Ohio State University and has worked on a wide array of research, including topics in hydrology, hydraulics, water quality, water use, modeling, and applied statistics. Greg teaches a USGS national training course on sediment and chemical loading computation methods and was an adjunct professor at the Ohio State University where he taught applied hydrology.
Science and Products
Filter Total Items: 53
Methods for estimating selected low-flow statistics and development of annual flow-duration statistics for Ohio Methods for estimating selected low-flow statistics and development of annual flow-duration statistics for Ohio
This report presents the results of a study to develop methods for estimating selected low-flow statistics and for determining annual flow-duration statistics for Ohio streams. Regression techniques were used to develop equations for estimating 10-year recurrence-interval (10-percent annual-nonexceedance probability) low-flow yields, in cubic feet per second per square mile, with...
Authors
G. F. Koltun, Stephanie P. Kula
Application of AFINCH as a tool for evaluating the effects of streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the southeast Lake Michigan hydrologic subregion Application of AFINCH as a tool for evaluating the effects of streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the southeast Lake Michigan hydrologic subregion
Bootstrapping techniques employing random subsampling were used with the AFINCH (Analysis of Flows In Networks of CHannels) model to gain insights into the effects of variation in streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the 0405 (Southeast Lake Michigan) hydrologic subregion. AFINCH uses stepwise...
Authors
G. F. Koltun, David J. Holtschlag
Statistical assessment of DNA extraction reagent lot variability in real-time quantitative PCR Statistical assessment of DNA extraction reagent lot variability in real-time quantitative PCR
Aims: The aim of this study was to evaluate the variability in lots of a DNA extraction kit using real-time PCR assays for Bacillus anthracis, Francisella tularensis and Vibrio cholerae. Methods and Results: Replicate aliquots of three bacteria were processed in duplicate with three different lots of a commercial DNA extraction kit. This experiment was repeated in triplicate. Results...
Authors
R.N. Bushon, C.M. Kephart, G. F. Koltun, D.S. Francy, F. W. Schaefer, H.D. Alan Lindquist
Annual peak-flow frequency characteristics and (or) peak dam-pool-elevation frequency characteristics of dry dams and selected streamflow-gaging stations in the Great Miami River Basin, Ohio Annual peak-flow frequency characteristics and (or) peak dam-pool-elevation frequency characteristics of dry dams and selected streamflow-gaging stations in the Great Miami River Basin, Ohio
This report describes the results of a study to determine frequency characteristics of postregulation annual peak flows at streamflow-gaging stations at or near the Lockington, Taylorsville, Englewood, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio) and five other streamflow-gaging stations in the Great Miami River Basin...
Authors
G. F. Koltun
Annual Peak-Flow and Peak Dam-Pool-Elevation Frequency Characteristics of Selected Dry Dams in the Great Miami River Basin, Ohio Annual Peak-Flow and Peak Dam-Pool-Elevation Frequency Characteristics of Selected Dry Dams in the Great Miami River Basin, Ohio
This report describes the results of a study to determine frequency characteristics of post-regulation annual peak flows at streamflow-gaging stations near the Taylorsville, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio), and of annual peak elevations of the corresponding dam pools. Log-Pearson Type III distributions were...
Authors
G. F. Koltun
Occurrence of organic wastewater compounds in the Tinkers Creek watershed and two other tributaries to the Cuyahoga River, northeast Ohio Occurrence of organic wastewater compounds in the Tinkers Creek watershed and two other tributaries to the Cuyahoga River, northeast Ohio
The U.S. Geological Survey - in cooperation with the Ohio Water Development Authority; National Park Service; Cities of Aurora, Bedford, Bedford Heights, Solon, and Twinsburg; and Portage and Summit Counties - and in collaboration with the Ohio Environmental Protection Agency, did a study to determine the occurrence and distribution of organic wastewater compounds (OWCs) in the Tinkers...
Authors
J.S. Tertuliani, D.A. Alvarez, E. T. Furlong, M. T. Meyer, S.D. Zaugg, G. F. Koltun
Science and Products
Filter Total Items: 53
Methods for estimating selected low-flow statistics and development of annual flow-duration statistics for Ohio Methods for estimating selected low-flow statistics and development of annual flow-duration statistics for Ohio
This report presents the results of a study to develop methods for estimating selected low-flow statistics and for determining annual flow-duration statistics for Ohio streams. Regression techniques were used to develop equations for estimating 10-year recurrence-interval (10-percent annual-nonexceedance probability) low-flow yields, in cubic feet per second per square mile, with...
Authors
G. F. Koltun, Stephanie P. Kula
Application of AFINCH as a tool for evaluating the effects of streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the southeast Lake Michigan hydrologic subregion Application of AFINCH as a tool for evaluating the effects of streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the southeast Lake Michigan hydrologic subregion
Bootstrapping techniques employing random subsampling were used with the AFINCH (Analysis of Flows In Networks of CHannels) model to gain insights into the effects of variation in streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the 0405 (Southeast Lake Michigan) hydrologic subregion. AFINCH uses stepwise...
Authors
G. F. Koltun, David J. Holtschlag
Statistical assessment of DNA extraction reagent lot variability in real-time quantitative PCR Statistical assessment of DNA extraction reagent lot variability in real-time quantitative PCR
Aims: The aim of this study was to evaluate the variability in lots of a DNA extraction kit using real-time PCR assays for Bacillus anthracis, Francisella tularensis and Vibrio cholerae. Methods and Results: Replicate aliquots of three bacteria were processed in duplicate with three different lots of a commercial DNA extraction kit. This experiment was repeated in triplicate. Results...
Authors
R.N. Bushon, C.M. Kephart, G. F. Koltun, D.S. Francy, F. W. Schaefer, H.D. Alan Lindquist
Annual peak-flow frequency characteristics and (or) peak dam-pool-elevation frequency characteristics of dry dams and selected streamflow-gaging stations in the Great Miami River Basin, Ohio Annual peak-flow frequency characteristics and (or) peak dam-pool-elevation frequency characteristics of dry dams and selected streamflow-gaging stations in the Great Miami River Basin, Ohio
This report describes the results of a study to determine frequency characteristics of postregulation annual peak flows at streamflow-gaging stations at or near the Lockington, Taylorsville, Englewood, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio) and five other streamflow-gaging stations in the Great Miami River Basin...
Authors
G. F. Koltun
Annual Peak-Flow and Peak Dam-Pool-Elevation Frequency Characteristics of Selected Dry Dams in the Great Miami River Basin, Ohio Annual Peak-Flow and Peak Dam-Pool-Elevation Frequency Characteristics of Selected Dry Dams in the Great Miami River Basin, Ohio
This report describes the results of a study to determine frequency characteristics of post-regulation annual peak flows at streamflow-gaging stations near the Taylorsville, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio), and of annual peak elevations of the corresponding dam pools. Log-Pearson Type III distributions were...
Authors
G. F. Koltun
Occurrence of organic wastewater compounds in the Tinkers Creek watershed and two other tributaries to the Cuyahoga River, northeast Ohio Occurrence of organic wastewater compounds in the Tinkers Creek watershed and two other tributaries to the Cuyahoga River, northeast Ohio
The U.S. Geological Survey - in cooperation with the Ohio Water Development Authority; National Park Service; Cities of Aurora, Bedford, Bedford Heights, Solon, and Twinsburg; and Portage and Summit Counties - and in collaboration with the Ohio Environmental Protection Agency, did a study to determine the occurrence and distribution of organic wastewater compounds (OWCs) in the Tinkers...
Authors
J.S. Tertuliani, D.A. Alvarez, E. T. Furlong, M. T. Meyer, S.D. Zaugg, G. F. Koltun