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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

link
Grand River near Painesville, OH - ice jam

Grand River near Painesville, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Grand River near Painesville, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More
link
Huron River at Milan, OH

Huron River near Milan, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Huron River near Milan, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More
link
Black River at Elyria, OH - bridge view

Black River at Elyria, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Black River at Elyria, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More
link
Cuyahoga River at Independence OH - view from river bank

Cuyahoga River at Independence, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Cuyahoga River at Independence, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More

Supporting data for low-flow statistics computed for streamflow gages and methods for estimating selected low-flow statistics for ungaged stream locations in Ohio, water years 1975–2020

This data release comprises the tabular data used to develop regression equations for estimating selected low-flow statistics for ungaged streams in Ohio that are not substantially affected by regulation, diversions, or other anthropogenic influences, and the geographic information systems (GIS) layer to implement them in the U.S. Geological Survey StreamStats application (https://streamstats.usgs
By
Ohio-Kentucky-Indiana Water Science Center

Annual streamflow statistics for selected streamgages in and near the shale play area of eastern Ohio (through water year 2021)

This data release includes datasets with annual streamflow statistics determined with the Indicators of Hydrologic Alteration software and R source code to create time-series plots with overlaid locally weighted scatterplot smoothing (lowess) lines.

Phosphorus, nitrogen, and suspended-sediment loads measured at the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2020

Phosphorus, nitrogen, and suspended-sediment loads, in 24 U.S. tributaries of the Great Lakes, were calculated using U.S. Geological Survey (USGS) data from the Great Lakes Restoration Initiative (GLRI) monitoring program for the period Oct 2010 through Sept 2020 (USGS water years 2011–2020). Total phosphorus, orthophosphate, particulate phosphorus, total nitrogen, nitrate plus nitrite, ammonium p
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Model data archive—Trends in Selected Environmental, Anthropogenic, and Water-Quality Characteristics in the Upper White River Basin, Indiana, 1991–2020

This archive contains input files used in regression analyses to estimate concentrations and flux of total phosphorus, nitrate plus nitrite, total Kjeldahl nitrogen, and total suspended solids at selected locations on the Upper White River and output files containing annual estimates of flux and mean daily concentrations.of those same constituents, along with their 90 percent prediction intervals.
By
Ohio-Kentucky-Indiana Water Science Center

Dataset for Analyses in Assessment of Runoff Volume Reduction Associated with Soil Amendments Added to Portions of Highway Median-Strip Catchments in Ohio

Rainfall and runoff data were collected during non-winter months between 2018 and 2020 at 10 rain gages and 12 calibrated H-flumes located in Ohio Department of Transportation (ODOT) highway median-strip catchments. The data were used to compute event-based summary statistics of rainfall and runoff. A rainfall-runoff "event" was defined to begin at the time of the first measured rainfall and end w
By
Ohio-Kentucky-Indiana Water Science Center

Total suspended solids, total phosphorus, nitrate plus nitrite, and total Kjeldahl nitrogen concentration data for the White River at Muncie, Indiana, 1991-2017

Data release contains total suspended solids, total phosphorus, nitrate plus nitrite, and total Kjeldahl nitrogen concentration data for the White River at Muncie, near Nora, and near Centerton, Indiana, 1991-2017, and R source code used for model development.
By
Ohio-Kentucky-Indiana Water Science Center

Geospatial Tools Effectively Estimate Nonexceedance Probabilities of Daily Streamflow at Ungaged and Intermittently Gaged Locations in Ohio: Data Release

This data set archives all inputs, outputs and scripts needed to reproduce the findings of W.H. Farmer and G.F. Koltun in the 2017 Journal of Hydrology Regional Studies article entitled Geospatial Tools Effectively Estimated Nonexceedance Probabilities of Daily Streamflow at Ungauged and Intermittently Gauged Locations in Ohio. Input data includes observed streamflow values, in cubic feet per seco
By
Water Resources Mission Area
Filter Total Items: 52

Low-flow statistics computed for streamflow gages and methods for estimating selected low-flow statistics for ungaged stream locations in Ohio, water years 1975–2020

A study was conducted by the U.S. Geological Survey, in cooperation with the Ohio Water Development Authority and the Ohio Environmental Protection Agency, to compute low-flow frequency, flow-duration, and harmonic mean flow statistics for long-term streamflow gages and to develop regression equations to estimate those statistics at unregulated, ungaged stream locations in Ohio. The flow statistic
Authors
Branden L. VonIns, G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Analysis of water use associated with hydraulic fracturing and determination of baseline water quality in watersheds within the shale play of eastern Ohio, 2021–23

The U.S. Geological Survey, in cooperation with the Ohio Department of Natural Resources, performed a two-part study to (1) assess water use and temporal trends and changes in streamflow, and to (2) characterize 2021–23 baseline water quality, as they relate to oil and gas extraction activities in selected eastern Ohio watersheds. Between calendar years 2010 and 2019, hydraulic fracturing water wi
Authors
S. Alex Covert, G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Potential drivers of change in fluxes of nutrients and total suspended solids in the upper White River Basin, Indiana, Water Years 1997–2019

The U.S. Geological Survey and The Nature Conservancy previously collaborated to evaluate changes and trends in the concentrations and flux of nutrients (total phosphorus, as phosphorus; nitrate plus nitrite, as nitrogen; and total Kjeldahl nitrogen, as nitrogen) and total suspended solids (TSS) at three study gages located on the upper White River at Muncie, near Nora, and near Centerton, Indiana
Authors
G.F. Koltun, Cassie Hauswald
By
Ohio-Kentucky-Indiana Water Science Center

Trends in environmental, anthropogenic, and water-quality characteristics in the upper White River Basin, Indiana

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, undertook a study to update and extend results from a previous study (Koltun, 2019, https://doi.org/10.3133/sir20195119), using data from 3 additional years and newer estimation methods. Koltun (2019) assessed trends in streamflow, precipitation, and estimated annual mean concentrations and flux of nitrate plus nitrite,
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Assessment of runoff volume reduction associated with soil amendments added to portions of highway median-strip catchments in Ohio, 2018–20

The U.S. Geological Survey installed 10 rain gages and 12 calibrated H-flumes to measure rainfall and runoff volumes at 10 locations in Ohio Department of Transportation highway median-strip catchments. Data were collected to facilitate comparisons of rainfall and runoff volumes at study sites before and after stormwater best management practices (BMPs) were installed and between sites with differ
Authors
Matthew T. Whitehead, G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Estimated total phosphorus loads for selected sites on Great Lakes tributaries, water years 2014–2018

Monthly and annual total phosphorus loads were estimated for water years 2014 through 2018 for 23 streamgaged (gaged) sites on tributaries to the Great Lakes. Processing and regression methods described by Robertson and others (2018) were used with discrete and continuous data collected during water years 2011 and 2018 to update regression models for estimating instantaneous flux with the same for
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Trends in streamflow, nutrients, and total suspended solids in the Upper White River Basin, Indiana

The U.S. Geological Survey, in partnership with The Nature Conservancy, analyzed existing water-quality and streamflow data from three locations in the Upper White River Basin, Indiana, to estimate annual mean concentrations and fluxes and to identify and quantify changes in water quality and streamflow over time. Water-quality data used in the analyses were collected between water years 1992 and
Authors
G.F. Koltun, Cassie Hauswald
By
Ohio-Kentucky-Indiana Water Science Center

Trends in streamflow and concentrations and flux of nutrients and total suspended solids in the Upper White River at Muncie, near Nora, and near Centerton, Indiana

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, completed a study to estimate and assess trends in streamflow and annual mean concentrations and flux of nutrients (nitrate plus nitrite, total Kjeldahl nitrogen, and total phosphorus) and total suspended solids at three USGS streamgages (hereafter referred to as “study gages”) on the Upper White River at Muncie (USGS s
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Flood-frequency estimates for Ohio streamgages based on data through water year 2015 and techniques for estimating flood-frequency characteristics of rural, unregulated Ohio streams

Estimates of the magnitudes of annual peak streamflows with annual exceedance probabilities of 0.5, 0.2, 0.1, 0.04, 0.02, 0.01, and 0.002 (equivalent to recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years, respectively) were computed for 391 streamgages in Ohio and adjacent states based on data collected through the 2015 water year. The flood-frequency estimates were computed follow
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center, StreamStats

Geospatial tools effectively estimate nonexceedance probabilities of daily streamflow at ungauged and intermittently gauged locations in Ohio

Study regionThe state of Ohio in the United States, a humid, continental climate.Study focusThe estimation of nonexceedance probabilities of daily streamflows as an alternative means of establishing the relative magnitudes of streamflows associated with hydrologic and water-quality observations.New hydrological insights for the regionSeveral methods for estimating nonexceedance probabilities of da
Authors
William H. Farmer, G.F. Koltun

Estimation of upstream water use with Ohio’s StreamStats application

This report describes the analytical methods and results of a pilot study to enhance the Ohio StreamStats application by adding the ability to obtain water-use information for selected areas in the northeast quadrant of Ohio. Water-use estimates are determined in StreamStats through a simple multistep process.  Water-use data used to develop the Ohio StreamStats water-use application were obtained
Authors
G. F. Koltun, Mark R. Nardi, Kimberly H. Shaffer
By
Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center

Hydrologic and hydraulic analyses for the Black Fork Mohican River Basin in and near Shelby, Ohio

Hydrologic and hydraulic analyses were done for selected reaches of five streams in and near Shelby, Richland County, Ohio. The U.S. Geological Survey (USGS), in cooperation with the Muskingum Watershed Conservancy District, conducted these analyses on the Black Fork Mohican River and four tributaries: Seltzer Park Creek, Seltzer Park Tributary, Tuby Run, and West Branch. Drainage areas of the fou
Authors
Carrie A. Huitger, Chad J. Ostheimer, G. F. Koltun
By
Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center

Culvert Analysis Program (CAP) version 2021.0.0

The culvert analysis program (CAP) version 2021 updates and corrects know errors in standalone versions 98-07c or earlier and iRIC version 3.X or earlier.
By
Ohio-Kentucky-Indiana Water Science Center

GCLAS (Graphical Constituent Loading Analysis System): A tool for computing loads of constituents transported in rivers

GCLAS is a program designed to compute daily and annual loadings of constituents transported in rivers. 

By
Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center

Science and Products

link
Grand River near Painesville, OH - ice jam

Grand River near Painesville, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Grand River near Painesville, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More
link
Huron River at Milan, OH

Huron River near Milan, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Huron River near Milan, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More
link
Black River at Elyria, OH - bridge view

Black River at Elyria, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Black River at Elyria, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More
link
Cuyahoga River at Independence OH - view from river bank

Cuyahoga River at Independence, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
By
Ohio-Kentucky-Indiana Water Science Center
link

Cuyahoga River at Independence, OH

Water-quality “super” gages (also known as “sentry” gages) provide real-time, continuous measurements of the physical and chemical characteristics of stream water at or near selected U.S. Geological Survey (USGS) streamgages in Ohio, Kentucky, and Indiana. A super gage includes streamflow and water-quality instrumentation and representative stream sample collection for laboratory analysis. USGS...
Learn More

Supporting data for low-flow statistics computed for streamflow gages and methods for estimating selected low-flow statistics for ungaged stream locations in Ohio, water years 1975–2020

This data release comprises the tabular data used to develop regression equations for estimating selected low-flow statistics for ungaged streams in Ohio that are not substantially affected by regulation, diversions, or other anthropogenic influences, and the geographic information systems (GIS) layer to implement them in the U.S. Geological Survey StreamStats application (https://streamstats.usgs
By
Ohio-Kentucky-Indiana Water Science Center

Annual streamflow statistics for selected streamgages in and near the shale play area of eastern Ohio (through water year 2021)

This data release includes datasets with annual streamflow statistics determined with the Indicators of Hydrologic Alteration software and R source code to create time-series plots with overlaid locally weighted scatterplot smoothing (lowess) lines.

Phosphorus, nitrogen, and suspended-sediment loads measured at the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2020

Phosphorus, nitrogen, and suspended-sediment loads, in 24 U.S. tributaries of the Great Lakes, were calculated using U.S. Geological Survey (USGS) data from the Great Lakes Restoration Initiative (GLRI) monitoring program for the period Oct 2010 through Sept 2020 (USGS water years 2011–2020). Total phosphorus, orthophosphate, particulate phosphorus, total nitrogen, nitrate plus nitrite, ammonium p
By
Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Model data archive—Trends in Selected Environmental, Anthropogenic, and Water-Quality Characteristics in the Upper White River Basin, Indiana, 1991–2020

This archive contains input files used in regression analyses to estimate concentrations and flux of total phosphorus, nitrate plus nitrite, total Kjeldahl nitrogen, and total suspended solids at selected locations on the Upper White River and output files containing annual estimates of flux and mean daily concentrations.of those same constituents, along with their 90 percent prediction intervals.
By
Ohio-Kentucky-Indiana Water Science Center

Dataset for Analyses in Assessment of Runoff Volume Reduction Associated with Soil Amendments Added to Portions of Highway Median-Strip Catchments in Ohio

Rainfall and runoff data were collected during non-winter months between 2018 and 2020 at 10 rain gages and 12 calibrated H-flumes located in Ohio Department of Transportation (ODOT) highway median-strip catchments. The data were used to compute event-based summary statistics of rainfall and runoff. A rainfall-runoff "event" was defined to begin at the time of the first measured rainfall and end w
By
Ohio-Kentucky-Indiana Water Science Center

Total suspended solids, total phosphorus, nitrate plus nitrite, and total Kjeldahl nitrogen concentration data for the White River at Muncie, Indiana, 1991-2017

Data release contains total suspended solids, total phosphorus, nitrate plus nitrite, and total Kjeldahl nitrogen concentration data for the White River at Muncie, near Nora, and near Centerton, Indiana, 1991-2017, and R source code used for model development.
By
Ohio-Kentucky-Indiana Water Science Center

Geospatial Tools Effectively Estimate Nonexceedance Probabilities of Daily Streamflow at Ungaged and Intermittently Gaged Locations in Ohio: Data Release

This data set archives all inputs, outputs and scripts needed to reproduce the findings of W.H. Farmer and G.F. Koltun in the 2017 Journal of Hydrology Regional Studies article entitled Geospatial Tools Effectively Estimated Nonexceedance Probabilities of Daily Streamflow at Ungauged and Intermittently Gauged Locations in Ohio. Input data includes observed streamflow values, in cubic feet per seco
By
Water Resources Mission Area
Filter Total Items: 52

Low-flow statistics computed for streamflow gages and methods for estimating selected low-flow statistics for ungaged stream locations in Ohio, water years 1975–2020

A study was conducted by the U.S. Geological Survey, in cooperation with the Ohio Water Development Authority and the Ohio Environmental Protection Agency, to compute low-flow frequency, flow-duration, and harmonic mean flow statistics for long-term streamflow gages and to develop regression equations to estimate those statistics at unregulated, ungaged stream locations in Ohio. The flow statistic
Authors
Branden L. VonIns, G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Analysis of water use associated with hydraulic fracturing and determination of baseline water quality in watersheds within the shale play of eastern Ohio, 2021–23

The U.S. Geological Survey, in cooperation with the Ohio Department of Natural Resources, performed a two-part study to (1) assess water use and temporal trends and changes in streamflow, and to (2) characterize 2021–23 baseline water quality, as they relate to oil and gas extraction activities in selected eastern Ohio watersheds. Between calendar years 2010 and 2019, hydraulic fracturing water wi
Authors
S. Alex Covert, G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Potential drivers of change in fluxes of nutrients and total suspended solids in the upper White River Basin, Indiana, Water Years 1997–2019

The U.S. Geological Survey and The Nature Conservancy previously collaborated to evaluate changes and trends in the concentrations and flux of nutrients (total phosphorus, as phosphorus; nitrate plus nitrite, as nitrogen; and total Kjeldahl nitrogen, as nitrogen) and total suspended solids (TSS) at three study gages located on the upper White River at Muncie, near Nora, and near Centerton, Indiana
Authors
G.F. Koltun, Cassie Hauswald
By
Ohio-Kentucky-Indiana Water Science Center

Trends in environmental, anthropogenic, and water-quality characteristics in the upper White River Basin, Indiana

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, undertook a study to update and extend results from a previous study (Koltun, 2019, https://doi.org/10.3133/sir20195119), using data from 3 additional years and newer estimation methods. Koltun (2019) assessed trends in streamflow, precipitation, and estimated annual mean concentrations and flux of nitrate plus nitrite,
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Assessment of runoff volume reduction associated with soil amendments added to portions of highway median-strip catchments in Ohio, 2018–20

The U.S. Geological Survey installed 10 rain gages and 12 calibrated H-flumes to measure rainfall and runoff volumes at 10 locations in Ohio Department of Transportation highway median-strip catchments. Data were collected to facilitate comparisons of rainfall and runoff volumes at study sites before and after stormwater best management practices (BMPs) were installed and between sites with differ
Authors
Matthew T. Whitehead, G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Estimated total phosphorus loads for selected sites on Great Lakes tributaries, water years 2014–2018

Monthly and annual total phosphorus loads were estimated for water years 2014 through 2018 for 23 streamgaged (gaged) sites on tributaries to the Great Lakes. Processing and regression methods described by Robertson and others (2018) were used with discrete and continuous data collected during water years 2011 and 2018 to update regression models for estimating instantaneous flux with the same for
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Trends in streamflow, nutrients, and total suspended solids in the Upper White River Basin, Indiana

The U.S. Geological Survey, in partnership with The Nature Conservancy, analyzed existing water-quality and streamflow data from three locations in the Upper White River Basin, Indiana, to estimate annual mean concentrations and fluxes and to identify and quantify changes in water quality and streamflow over time. Water-quality data used in the analyses were collected between water years 1992 and
Authors
G.F. Koltun, Cassie Hauswald
By
Ohio-Kentucky-Indiana Water Science Center

Trends in streamflow and concentrations and flux of nutrients and total suspended solids in the Upper White River at Muncie, near Nora, and near Centerton, Indiana

The U.S. Geological Survey (USGS), in cooperation with The Nature Conservancy, completed a study to estimate and assess trends in streamflow and annual mean concentrations and flux of nutrients (nitrate plus nitrite, total Kjeldahl nitrogen, and total phosphorus) and total suspended solids at three USGS streamgages (hereafter referred to as “study gages”) on the Upper White River at Muncie (USGS s
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center

Flood-frequency estimates for Ohio streamgages based on data through water year 2015 and techniques for estimating flood-frequency characteristics of rural, unregulated Ohio streams

Estimates of the magnitudes of annual peak streamflows with annual exceedance probabilities of 0.5, 0.2, 0.1, 0.04, 0.02, 0.01, and 0.002 (equivalent to recurrence intervals of 2-, 5-, 10-, 25-, 50-, 100-, and 500-years, respectively) were computed for 391 streamgages in Ohio and adjacent states based on data collected through the 2015 water year. The flood-frequency estimates were computed follow
Authors
G.F. Koltun
By
Ohio-Kentucky-Indiana Water Science Center, StreamStats

Geospatial tools effectively estimate nonexceedance probabilities of daily streamflow at ungauged and intermittently gauged locations in Ohio

Study regionThe state of Ohio in the United States, a humid, continental climate.Study focusThe estimation of nonexceedance probabilities of daily streamflows as an alternative means of establishing the relative magnitudes of streamflows associated with hydrologic and water-quality observations.New hydrological insights for the regionSeveral methods for estimating nonexceedance probabilities of da
Authors
William H. Farmer, G.F. Koltun

Estimation of upstream water use with Ohio’s StreamStats application

This report describes the analytical methods and results of a pilot study to enhance the Ohio StreamStats application by adding the ability to obtain water-use information for selected areas in the northeast quadrant of Ohio. Water-use estimates are determined in StreamStats through a simple multistep process.  Water-use data used to develop the Ohio StreamStats water-use application were obtained
Authors
G. F. Koltun, Mark R. Nardi, Kimberly H. Shaffer
By
Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center

Hydrologic and hydraulic analyses for the Black Fork Mohican River Basin in and near Shelby, Ohio

Hydrologic and hydraulic analyses were done for selected reaches of five streams in and near Shelby, Richland County, Ohio. The U.S. Geological Survey (USGS), in cooperation with the Muskingum Watershed Conservancy District, conducted these analyses on the Black Fork Mohican River and four tributaries: Seltzer Park Creek, Seltzer Park Tributary, Tuby Run, and West Branch. Drainage areas of the fou
Authors
Carrie A. Huitger, Chad J. Ostheimer, G. F. Koltun
By
Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center

Culvert Analysis Program (CAP) version 2021.0.0

The culvert analysis program (CAP) version 2021 updates and corrects know errors in standalone versions 98-07c or earlier and iRIC version 3.X or earlier.
By
Ohio-Kentucky-Indiana Water Science Center

GCLAS (Graphical Constituent Loading Analysis System): A tool for computing loads of constituents transported in rivers

GCLAS is a program designed to compute daily and annual loadings of constituents transported in rivers. 

By
Water Resources Mission Area, Ohio-Kentucky-Indiana Water Science Center
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