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
Morphological Analyses and Simulated Flood Elevations in a Watershed with Dredged and Leveed Stream Channels, Wheeling Creek, Eastern Ohio Morphological Analyses and Simulated Flood Elevations in a Watershed with Dredged and Leveed Stream Channels, Wheeling Creek, Eastern Ohio
The USGS, in cooperation with the Ohio Emergency Management Agency, conducted a study in the Wheeling Creek Basin to (1) evaluate and contrast land-cover characteristics from 2001 with characteristics from 1979 and 1992; (2) compare current streambed elevation, slope, and geometry with conditions present in the late 1980s; (3) look for evidence of channel filling and over widening in...
Authors
James Sherwood, Carrie Huitger, Andrew Ebner, G. F. Koltun
Flood of June 22-24, 2006, in North-Central Ohio, With Emphasis on the Cuyahoga River Near Independence Flood of June 22-24, 2006, in North-Central Ohio, With Emphasis on the Cuyahoga River Near Independence
Heavy rains caused severe flooding on June 22-24, 2006, and damaged approximately 4,580 homes and 48 businesses in Cuyahoga County. Damage estimates in Cuyahoga County for the two days of flooding exceed $47 million; statewide damage estimates exceed $150 million. Six counties (Cuyahoga, Erie, Huron, Lucas, Sandusky, and Stark) in northeast Ohio were declared Federal disaster areas. One...
Authors
James Sherwood, Andrew Ebner, G. F. Koltun, Brian Astifan
User's manual for the Graphical Constituent Loading Analysis System (GCLAS) User's manual for the Graphical Constituent Loading Analysis System (GCLAS)
This manual describes the Graphical Constituent Loading Analysis System (GCLAS), an interactive cross-platform program for computing the mass (load) and average concentration of a constituent that is transported in stream water over a period of time. GCLAS computes loads as a function of an equal-interval streamflow time series and an equal- or unequal-interval time series of constituent
Authors
G. F. Koltun, Michael Eberle, J. Gray, G.D. Glysson
Velocity, bathymetry, and transverse mixing characteristics of the Ohio River upstream from Cincinnati, Ohio, October 2004–March 2006 Velocity, bathymetry, and transverse mixing characteristics of the Ohio River upstream from Cincinnati, Ohio, October 2004–March 2006
Velocity, bathymetry, and transverse (cross-channel) mixing characteristics were studied in a 34-mile study reach of the Ohio River extending from the lower pool of the Captain Anthony Meldahl Lock and Dam, near Willow Grove, Ky, to just downstream from the confluence of the Licking and Ohio Rivers, near Newport, Ky. Information gathered in this study ultimately will be used to...
Authors
G. F. Koltun, Chad Ostheimer, Michael Griffin
A Streamflow Statistics (StreamStats) Web Application for Ohio A Streamflow Statistics (StreamStats) Web Application for Ohio
A StreamStats Web application was developed for Ohio that implements equations for estimating a variety of streamflow statistics including the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year peak streamflows, mean annual streamflow, mean monthly streamflows, harmonic mean streamflow, and 25th-, 50th-, and 75th-percentile streamflows. StreamStats is a Web-based geographic information system...
Authors
G. F. Koltun, Stephanie Kula, Barry Puskas
Upper Auglaize watershed AGNPS modeling project Upper Auglaize watershed AGNPS modeling project
The Upper Auglaize Watershed agricultural non-point source modeling project was an interagency effort to use a Geographic Information System (GIS)-based modeling approach for assessing and reducing pollution from agricultural runoff and other non-point sources. This project applied the U.S. Department of Agriculture (USDA), Agricultural Research Service’s AGricultural Non-Point Source...
Authors
Ronald Bingner, Kevin Czajkowski, Michael Palmer, James Coss, Steve Davis, Jim Stafford, Norm Wideman, Fred Theurer, G. Koltun, Pete Richards, Tony Friona
Microbiological Water Quality in Relation to Water-Contact Recreation, Cuyahoga River, Cuyahoga Valley National Park, Ohio, 2000 and 2002 Microbiological Water Quality in Relation to Water-Contact Recreation, Cuyahoga River, Cuyahoga Valley National Park, Ohio, 2000 and 2002
The microbiological water quality of a 23-mile segment of the Cuyahoga River within the Cuyahoga Valley National Park was examined in this study. This segment of the river receives discharges of contaminated water from stormwater, combined-sewer overflows, and incompletely disinfected wastewater. Frequent exceedances of Ohio microbiological water-quality standards result in a health risk...
Authors
Rebecca Bushon, G. F. Koltun
Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio
Regional equations for estimating 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood-peak discharges at ungaged sites on rural, unregulated streams in Ohio were developed by means of ordinary and generalized least-squares (GLS) regression techniques. One-variable, simple equations and three-variable, full-model equations were developed on the basis of selected basin characteristics and...
Authors
G. F. Koltun
By
Techniques for estimating selected streamflow characteristics of rural, unregulated streams in Ohio Techniques for estimating selected streamflow characteristics of rural, unregulated streams in Ohio
This report provides equations for estimating mean annual streamflow, mean monthly streamflows, harmonic mean streamflow, and streamflow quartiles (the 25th-, 50th-, and 75th-percentile streamflows) as a function of selected basin characteristics for rural, unregulated streams in Ohio. The equations were developed from streamflow statistics and basin-characteristics data for as many as...
Authors
G. F. Koltun, Matthew Whitehead
Trends in selected streamflow and stream-channel characteristics for the Chagrin River at Willoughby, Ohio Trends in selected streamflow and stream-channel characteristics for the Chagrin River at Willoughby, Ohio
Monotonic upward trends in annual mean streamflows and annual 7-day low flows were identified statistically for the streamflow-gaging station on the Chagrin River at Willoughby, Ohio. No monotonic trends were identified for the annual peak streamflow series or partial-duration series of peak streamflows augmented with annual peak streamflows that did not exceed a base discharge of 4,000...
Authors
G. F. Koltun, Allison Kunze
Hydrologic considerations for estimation of storage-capacity requirements of impounding and side-channel reservoirs for water supply in Ohio Hydrologic considerations for estimation of storage-capacity requirements of impounding and side-channel reservoirs for water supply in Ohio
This report provides data and methods to aid in the hydrologic design or evaluation of impounding reservoirs and side-channel reservoirs used for water supply in Ohio. Data from 117 streamflow-gaging stations throughout Ohio were analyzed by means of nonsequential-mass-curve-analysis techniques to develop relations between storage requirements, water demand, duration, and frequency...
Authors
G. F. Koltun
GCLAS: a graphical constituent loading analysis system GCLAS: a graphical constituent loading analysis system
The U. S. Geological Survey has developed a program called GCLAS (Graphical Constituent Loading Analysis System) to aid in the computation of daily constituent loads transported in stream flow. Due to the relative paucity with which most water-quality data are collected, computation of daily constituent loads is moderately to highly dependent on human interpretation of the relation...
Authors
T.E. McKallip, G. F. Koltun, J. Gray, G.D. Glysson
Science and Products
Filter Total Items: 53
Morphological Analyses and Simulated Flood Elevations in a Watershed with Dredged and Leveed Stream Channels, Wheeling Creek, Eastern Ohio Morphological Analyses and Simulated Flood Elevations in a Watershed with Dredged and Leveed Stream Channels, Wheeling Creek, Eastern Ohio
The USGS, in cooperation with the Ohio Emergency Management Agency, conducted a study in the Wheeling Creek Basin to (1) evaluate and contrast land-cover characteristics from 2001 with characteristics from 1979 and 1992; (2) compare current streambed elevation, slope, and geometry with conditions present in the late 1980s; (3) look for evidence of channel filling and over widening in...
Authors
James Sherwood, Carrie Huitger, Andrew Ebner, G. F. Koltun
Flood of June 22-24, 2006, in North-Central Ohio, With Emphasis on the Cuyahoga River Near Independence Flood of June 22-24, 2006, in North-Central Ohio, With Emphasis on the Cuyahoga River Near Independence
Heavy rains caused severe flooding on June 22-24, 2006, and damaged approximately 4,580 homes and 48 businesses in Cuyahoga County. Damage estimates in Cuyahoga County for the two days of flooding exceed $47 million; statewide damage estimates exceed $150 million. Six counties (Cuyahoga, Erie, Huron, Lucas, Sandusky, and Stark) in northeast Ohio were declared Federal disaster areas. One...
Authors
James Sherwood, Andrew Ebner, G. F. Koltun, Brian Astifan
User's manual for the Graphical Constituent Loading Analysis System (GCLAS) User's manual for the Graphical Constituent Loading Analysis System (GCLAS)
This manual describes the Graphical Constituent Loading Analysis System (GCLAS), an interactive cross-platform program for computing the mass (load) and average concentration of a constituent that is transported in stream water over a period of time. GCLAS computes loads as a function of an equal-interval streamflow time series and an equal- or unequal-interval time series of constituent
Authors
G. F. Koltun, Michael Eberle, J. Gray, G.D. Glysson
Velocity, bathymetry, and transverse mixing characteristics of the Ohio River upstream from Cincinnati, Ohio, October 2004–March 2006 Velocity, bathymetry, and transverse mixing characteristics of the Ohio River upstream from Cincinnati, Ohio, October 2004–March 2006
Velocity, bathymetry, and transverse (cross-channel) mixing characteristics were studied in a 34-mile study reach of the Ohio River extending from the lower pool of the Captain Anthony Meldahl Lock and Dam, near Willow Grove, Ky, to just downstream from the confluence of the Licking and Ohio Rivers, near Newport, Ky. Information gathered in this study ultimately will be used to...
Authors
G. F. Koltun, Chad Ostheimer, Michael Griffin
A Streamflow Statistics (StreamStats) Web Application for Ohio A Streamflow Statistics (StreamStats) Web Application for Ohio
A StreamStats Web application was developed for Ohio that implements equations for estimating a variety of streamflow statistics including the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year peak streamflows, mean annual streamflow, mean monthly streamflows, harmonic mean streamflow, and 25th-, 50th-, and 75th-percentile streamflows. StreamStats is a Web-based geographic information system...
Authors
G. F. Koltun, Stephanie Kula, Barry Puskas
Upper Auglaize watershed AGNPS modeling project Upper Auglaize watershed AGNPS modeling project
The Upper Auglaize Watershed agricultural non-point source modeling project was an interagency effort to use a Geographic Information System (GIS)-based modeling approach for assessing and reducing pollution from agricultural runoff and other non-point sources. This project applied the U.S. Department of Agriculture (USDA), Agricultural Research Service’s AGricultural Non-Point Source...
Authors
Ronald Bingner, Kevin Czajkowski, Michael Palmer, James Coss, Steve Davis, Jim Stafford, Norm Wideman, Fred Theurer, G. Koltun, Pete Richards, Tony Friona
Microbiological Water Quality in Relation to Water-Contact Recreation, Cuyahoga River, Cuyahoga Valley National Park, Ohio, 2000 and 2002 Microbiological Water Quality in Relation to Water-Contact Recreation, Cuyahoga River, Cuyahoga Valley National Park, Ohio, 2000 and 2002
The microbiological water quality of a 23-mile segment of the Cuyahoga River within the Cuyahoga Valley National Park was examined in this study. This segment of the river receives discharges of contaminated water from stormwater, combined-sewer overflows, and incompletely disinfected wastewater. Frequent exceedances of Ohio microbiological water-quality standards result in a health risk...
Authors
Rebecca Bushon, G. F. Koltun
Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio
Regional equations for estimating 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood-peak discharges at ungaged sites on rural, unregulated streams in Ohio were developed by means of ordinary and generalized least-squares (GLS) regression techniques. One-variable, simple equations and three-variable, full-model equations were developed on the basis of selected basin characteristics and...
Authors
G. F. Koltun
By
Techniques for estimating selected streamflow characteristics of rural, unregulated streams in Ohio Techniques for estimating selected streamflow characteristics of rural, unregulated streams in Ohio
This report provides equations for estimating mean annual streamflow, mean monthly streamflows, harmonic mean streamflow, and streamflow quartiles (the 25th-, 50th-, and 75th-percentile streamflows) as a function of selected basin characteristics for rural, unregulated streams in Ohio. The equations were developed from streamflow statistics and basin-characteristics data for as many as...
Authors
G. F. Koltun, Matthew Whitehead
Trends in selected streamflow and stream-channel characteristics for the Chagrin River at Willoughby, Ohio Trends in selected streamflow and stream-channel characteristics for the Chagrin River at Willoughby, Ohio
Monotonic upward trends in annual mean streamflows and annual 7-day low flows were identified statistically for the streamflow-gaging station on the Chagrin River at Willoughby, Ohio. No monotonic trends were identified for the annual peak streamflow series or partial-duration series of peak streamflows augmented with annual peak streamflows that did not exceed a base discharge of 4,000...
Authors
G. F. Koltun, Allison Kunze
Hydrologic considerations for estimation of storage-capacity requirements of impounding and side-channel reservoirs for water supply in Ohio Hydrologic considerations for estimation of storage-capacity requirements of impounding and side-channel reservoirs for water supply in Ohio
This report provides data and methods to aid in the hydrologic design or evaluation of impounding reservoirs and side-channel reservoirs used for water supply in Ohio. Data from 117 streamflow-gaging stations throughout Ohio were analyzed by means of nonsequential-mass-curve-analysis techniques to develop relations between storage requirements, water demand, duration, and frequency...
Authors
G. F. Koltun
GCLAS: a graphical constituent loading analysis system GCLAS: a graphical constituent loading analysis system
The U. S. Geological Survey has developed a program called GCLAS (Graphical Constituent Loading Analysis System) to aid in the computation of daily constituent loads transported in stream flow. Due to the relative paucity with which most water-quality data are collected, computation of daily constituent loads is moderately to highly dependent on human interpretation of the relation...
Authors
T.E. McKallip, G. F. Koltun, J. Gray, G.D. Glysson