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: 51
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 concentra
Authors
G. F. Koltun, Michael Eberle, J. R. 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 (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 parameterize hydrod
Authors
G. F. Koltun, Chad J. Ostheimer, Michael S. Griffin
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 application d
Authors
G. F. Koltun, Stephanie P. Kula, Barry M. Puskas
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 (AGNPS) suit
Authors
Ronald L. Bingner, Kevin Czajkowski, Michael Palmer, James Coss, Steve Davis, Jim Stafford, Norm Wideman, Fred D. Theurer, G.F. Koltun, Pete Richards, Tony Friona
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 to the pu
Authors
Rebecca N. Bushon, G. F. Koltun
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 flood-frequenc
Authors
G. F. Koltun
By
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 219 active
Authors
G. F. Koltun, Matthew T. Whitehead
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 cubic feet
Authors
G. F. Koltun, Allison E. Kunze
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. Information al
Authors
G. F. Koltun
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 between stream
Authors
T.E. McKallip, G. F. Koltun, J. R. Gray, G.D. Glysson
Floods of June 28-29, 1998 in Ohio
During a 96-hour period extending from June 26 to June 30, 1998, a stalled frontal system produced a series of storms that dumped 10 inches or more of rain on parts of Ohio. The storms occurred at the end of a relatively wet month, resulting in flooding and widespread damage throughout much of central, east-central, and southeastern Ohio. Twenty-three Ohio counties were declared Federal and State
Authors
G. F. Koltun
Factors related to probability of joint flooding on paired streams in Ohio
Factors related to the probability of joint flooding on paired streams were investigated. Stream pairs were considered to have flooded jointly at the design-year flood threshold (corresponding to the 2-, 10-, 25-, or 50-year instantaneous peak stream flow) if peak stream flows at both streams in the pair were observed or predicted to have equaled or exceeded the threshold on a given calendar day.
Authors
G. F. Koltun, J. M. Sherwood
Science and Products
Filter Total Items: 51
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 concentra
Authors
G. F. Koltun, Michael Eberle, J. R. 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 (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 parameterize hydrod
Authors
G. F. Koltun, Chad J. Ostheimer, Michael S. Griffin
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 application d
Authors
G. F. Koltun, Stephanie P. Kula, Barry M. Puskas
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 (AGNPS) suit
Authors
Ronald L. Bingner, Kevin Czajkowski, Michael Palmer, James Coss, Steve Davis, Jim Stafford, Norm Wideman, Fred D. Theurer, G.F. Koltun, Pete Richards, Tony Friona
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 to the pu
Authors
Rebecca N. Bushon, G. F. Koltun
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 flood-frequenc
Authors
G. F. Koltun
By
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 219 active
Authors
G. F. Koltun, Matthew T. Whitehead
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 cubic feet
Authors
G. F. Koltun, Allison E. Kunze
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. Information al
Authors
G. F. Koltun
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 between stream
Authors
T.E. McKallip, G. F. Koltun, J. R. Gray, G.D. Glysson
Floods of June 28-29, 1998 in Ohio
During a 96-hour period extending from June 26 to June 30, 1998, a stalled frontal system produced a series of storms that dumped 10 inches or more of rain on parts of Ohio. The storms occurred at the end of a relatively wet month, resulting in flooding and widespread damage throughout much of central, east-central, and southeastern Ohio. Twenty-three Ohio counties were declared Federal and State
Authors
G. F. Koltun
Factors related to probability of joint flooding on paired streams in Ohio
Factors related to the probability of joint flooding on paired streams were investigated. Stream pairs were considered to have flooded jointly at the design-year flood threshold (corresponding to the 2-, 10-, 25-, or 50-year instantaneous peak stream flow) if peak stream flows at both streams in the pair were observed or predicted to have equaled or exceeded the threshold on a given calendar day.
Authors
G. F. Koltun, J. M. Sherwood