David J Holtschlag, PStat
Starting in 1976, I have had a successful and enjoyable career as a hydrologist with the USGS. During more than 40 years, I participated in numerous field and research studies to characterize water resources in Michigan and parts of the Great Lakes. I am grateful and indebted to my colleagues for their professionalism, inspiration, and helpfulness.
David actively serves as an USGS Scientist Emeritus.
Professional Studies/Experience
Served as the Surface-Water Specialist for the USGS Michigan Water Science Center. Developed both 1- and 2-dimensional hydrodynamic models of surface-water bodies on the Great Lakes Waterway, Ohio River, and numerous rivers in Michigan. An unsteady 1-dimensional model of St. Clair River was developed to quantify changes in conveyance properties along individual reaches of the river using water-level gaging station data distributed throughout St. Clair River. A 2-dimensional model of St. Clair-Detroit River was developed to identify source areas to public-water intakes. A two-dimension model of the Ohio River was used to characterize flow and the dispersion of point discharge constituents based on a study using dye injections. Carried out flood frequency analysis and flood hydraulic analysis using standard models. Developed an Bayesian network model of multivariate water-quality constituents on the White River in Indiana to estimate an unmeasured subset of constituents based on an arbitrarily selected subset of measured constituents. Developed mixed effects statistical models to characterize the effects of irrigation, land use, precipitation, and temperature on selected basins in southwestern Michigan.
Mentorship/Outreach
Assisted early career hydrologists in the application of advanced statistical models including the mixed effects models and spatial models of hydrologic phenomena.
Current Interest
Development of state-space models to sequentially update parameter estimates of spline functions describing stage-discharge relations based on individual discrete-flow measurements. Apply Kalman filtering and smoothing to provide real-time and finalized estimates of the magnitudes and uncertainties of unit flow data based on unit stage data.
Education and Certifications
University of Missouri-Columbia, B.S.. in Forestry, 1974
University of Minnesota, M'S. Forest Hydrology, 1976
Michigan State University, M'S. System Science, 1990
Affiliations and Memberships*
American Statistical Association, Accredited Professional Statistician
Science and Products
Attributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
The U.S. Geological Survey Dakota Water Science Center, in cooperation with the Federal Highway Administration, analyzed annual peak-flow data to determine if trends are present and provide attribution of trends where possible. Work for the national trend attributions for nonstationary annual peak-flow records was broken into seven regions that are loosely based off of two-digit hydrologic unit wa
Factors Affecting Spatial and Temporal Variations of Annual Summer Median Water Yields in Southwestern Michigan
Median summer water yields and resultant flows are used in Michigan to regulate large water withdrawals to help prevent negative effects on characteristic fish populations. Large water withdrawals commonly are associated with irrigation in rural areas. In an earlier statewide report, an index-flow statistic for the period of record, defined as the median flow during the summer month of lowest flow
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
This U.S. Geological Survey (USGS) data release contains the data used in the USGS Scientific Investigations Report 2018-5053 entitled "An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data." The four datasets, which contain only ASCII characters in a
Code, data, executables, and other information used to run Unit Flows in Networks of Channels (UFINCH) - A method for simulating unit and daily flows in networks of channels described by NHDPlus using continuous flow data at U.S. Geological Survey streamg
This U.S. Geological Survey (USGS) data release contains the code, data, executables, and other information necessary to run the application Unit Flows in Networks of Channels (UFINCH). The UFINCH application is a computer code that utilizes the geospatial stream connectivity and catchment geometry described in National Hydrography Dataset Plus value added attributes (NHDPlus Version 2) to simulat
Precipitation and streamflow data for computing lag to peak at selected stations in Maine
These are rainfall and stream stage data collected at gaging sites in Maine. Data were collected from March to October from 2008 to 2015 and include stage data at crest stage gages, ratings to convert stage data to streamflow data, previously unpublished rainfall data, rainfall binned into specified time intervals, and storm files combining rainfall and streamflow data. Data were collected, compi
Filter Total Items: 48
A computer-aided approach for adapting stage-discharge ratings and characterizing uncertainties of streamflow data with discrete measurements
Relations between stage (water level) and discharge of streamflow through a natural channel are the result of time-varying processes, which are commonly described by time-varying stage-discharge ratings. Hydrographers with the U.S. Geological Survey successfully maintain the accuracy of streamflow data by manually applying time-tested approaches to adapt ratings to temporal changes in hydraulic co
Authors
David J. Holtschlag
Basin, climatic, and irrigation factors associated with median summer water yields for streams in Southwestern Michigan, 1945-2015
Median summer water yields and resultant flows for streams are used in Michigan to regulate large water withdrawals to help prevent negative effects on characteristic fish populations. Large water withdrawals commonly are associated with irrigation in rural areas. In an earlier statewide report, an index-flow statistic for the period of record, defined as the median flow during the summer month of
Authors
David J. Holtschlag
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
An exploratory discrete Bayesian network (BN) was developed to assess the potential of this type of model for estimating the magnitudes and uncertainties of an arbitrary subset of unmeasured water-quality parameters given the measured complement of parameters historically measured at a U.S. Geological Survey streamgage. Water-quality data for 27 water-quality parameters from 596 discrete measureme
Authors
David J. Holtschlag
UFINCH: A method for simulating unit and daily flows in networks of channels described by NHDPlus using continuous flow data at U.S. Geological Survey streamgages
The UFINCH (Unit Flows In Networks of Channels) computer application can be used to simulate daily and unit flows in networks of streams based on geospatial data in the National Hydrography Dataset NHDPlus (with value added attributes), and U.S. Geoogical Survey daily streamflow data from a downstream (or base) streamgage. Among streamflow augmentation methods, UFINCH has the unique capability to
Authors
David J. Holtschlag
Estimating lag to peak between rainfall and peak streamflow with a mixed-effects model
We test the use of a mixed-effects model for estimating lag to peak for small basins in Maine (drainage areas from 0.8 to 78 km2). Lag to peak is defined as the time between the center of volume of the excess rainfall during a storm event and the resulting peak streamflow. A mixed-effects model allows for multiple observations at sites without violating model assumptions inherent in traditional or
Authors
Pamela J. Lombard, David Holtschlag
An evaluation of methods for estimating decadal stream loads
Effective management of water resources requires accurate information on the mass, or load of water-quality constituents transported from upstream watersheds to downstream receiving waters. Despite this need, no single method has been shown to consistently provide accurate load estimates among different water-quality constituents, sampling sites, and sampling regimes. We evaluate the accuracy of s
Authors
Casey J. Lee, Robert M. Hirsch, Gregory E. Schwarz, David J. Holtschlag, Stephen D. Preston, Charles G. Crawford, Aldo V. Vecchia
Estimation of monthly water yields and flows for 1951-2012 for the United States portion of the Great Lakes Basin with AFINCH
Monthly water yields from 105,829 catchments and corresponding flows in 107,691 stream segments were estimated for water years 1951–2012 in the Great Lakes Basin in the United States. Both sets of estimates were computed by using the Analysis of Flows In Networks of CHannels (AFINCH) application within the NHDPlus geospatial data framework. AFINCH provides an environment to develop constrained reg
Authors
Carol L. Luukkonen, David J. Holtschlag, Howard W. Reeves, Christopher J. Hoard, Lori M. Fuller
Comparison of streamflow and water-quality data collection techniques for the Saginaw River, Michigan
In 2009, the Michigan Department of Environmental Quality and the U.S. Geological Survey developed a plan to compare the effect of various streamgaging and water-quality collection techniques on streamflow and stream water-quality data for the Saginaw River, Michigan. The Saginaw River is the primary contributor of surface runoff to Saginaw Bay, Lake Huron, draining approximately 70 percent of the
Authors
C. J. Hoard, D. J. Holtschlag, J.W. Duris, D.A. James, D.J. Obenauer
Use of instantaneous streamflow measurements to improve regression estimates of index flow for the summer month of lowest streamflow in Michigan
In Michigan, index flow Q50 is a streamflow characteristic defined as the minimum of median flows for July, August, and September. The state of Michigan uses index flow estimates to help regulate large (greater than 100,000 gallons per day) water withdrawals to prevent adverse effects on characteristic fish populations. At sites where long-term streamgages are located, index flows are computed dir
Authors
David J. Holtschlag
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-regression techni
Authors
G. F. Koltun, David J. Holtschlag
Application guide for AFINCH (Analysis of Flows in Networks of Channels) described by NHDPlus
AFINCH (Analysis of Flows in Networks of CHannels) is a computer application that can be used to generate a time series of monthly flows at stream segments (flowlines) and water yields for catchments defined in the National Hydrography Dataset Plus (NHDPlus) value-added attribute system. AFINCH provides a basis for integrating monthly flow data from streamgages, water-use data, monthly climatic da
Authors
David J. Holtschlag
An initial investigation of multidimensional flow and transverse mixing characteristics of the Ohio River near Cincinnati, Ohio
Two-dimensional hydrodynamic and transport models were applied to a 34-mile reach of the Ohio River from Cincinnati, Ohio, upstream to Meldahl Dam near Neville, Ohio. The hydrodynamic model was based on the generalized finite-element hydrodynamic code RMA2 to simulate depth-averaged velocities and flow depths. The generalized water-quality transport code RMA4 was applied to simulate the transport
Authors
David J. Holtschlag
UFINCH— A Method for Simulating Unit and Daily Flows in Networks of Channels Described by NHDPlus Using Continuous Flow Data at USGS Streamgages
The computer program UFINCH (Unit Flows in Networks of Channels) can be used to simulate unit (15-minute) flows in a network of streams defined within the medium resolution National Hydrography Dataset Plus with value added attributes (NHDPlus, v. 2).
Analysis of Flows in Networks of Channels (AFINCH)
AFINCH (Analysis of Flows in Networks of CHannels) is a computer application designed to generate time series of monthly flows at stream segments and corresponding water yields at catchments defined in the National Hydrography Dataset (NHDPlus, v. 2).
Science and Products
Attributions for nonstationary peak streamflow records across the conterminous United States, 1941-2015 and 1966-2015
The U.S. Geological Survey Dakota Water Science Center, in cooperation with the Federal Highway Administration, analyzed annual peak-flow data to determine if trends are present and provide attribution of trends where possible. Work for the national trend attributions for nonstationary annual peak-flow records was broken into seven regions that are loosely based off of two-digit hydrologic unit wa
Factors Affecting Spatial and Temporal Variations of Annual Summer Median Water Yields in Southwestern Michigan
Median summer water yields and resultant flows are used in Michigan to regulate large water withdrawals to help prevent negative effects on characteristic fish populations. Large water withdrawals commonly are associated with irrigation in rural areas. In an earlier statewide report, an index-flow statistic for the period of record, defined as the median flow during the summer month of lowest flow
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
This U.S. Geological Survey (USGS) data release contains the data used in the USGS Scientific Investigations Report 2018-5053 entitled "An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data." The four datasets, which contain only ASCII characters in a
Code, data, executables, and other information used to run Unit Flows in Networks of Channels (UFINCH) - A method for simulating unit and daily flows in networks of channels described by NHDPlus using continuous flow data at U.S. Geological Survey streamg
This U.S. Geological Survey (USGS) data release contains the code, data, executables, and other information necessary to run the application Unit Flows in Networks of Channels (UFINCH). The UFINCH application is a computer code that utilizes the geospatial stream connectivity and catchment geometry described in National Hydrography Dataset Plus value added attributes (NHDPlus Version 2) to simulat
Precipitation and streamflow data for computing lag to peak at selected stations in Maine
These are rainfall and stream stage data collected at gaging sites in Maine. Data were collected from March to October from 2008 to 2015 and include stage data at crest stage gages, ratings to convert stage data to streamflow data, previously unpublished rainfall data, rainfall binned into specified time intervals, and storm files combining rainfall and streamflow data. Data were collected, compi
Filter Total Items: 48
A computer-aided approach for adapting stage-discharge ratings and characterizing uncertainties of streamflow data with discrete measurements
Relations between stage (water level) and discharge of streamflow through a natural channel are the result of time-varying processes, which are commonly described by time-varying stage-discharge ratings. Hydrographers with the U.S. Geological Survey successfully maintain the accuracy of streamflow data by manually applying time-tested approaches to adapt ratings to temporal changes in hydraulic co
Authors
David J. Holtschlag
Basin, climatic, and irrigation factors associated with median summer water yields for streams in Southwestern Michigan, 1945-2015
Median summer water yields and resultant flows for streams are used in Michigan to regulate large water withdrawals to help prevent negative effects on characteristic fish populations. Large water withdrawals commonly are associated with irrigation in rural areas. In an earlier statewide report, an index-flow statistic for the period of record, defined as the median flow during the summer month of
Authors
David J. Holtschlag
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
An exploratory discrete Bayesian network (BN) was developed to assess the potential of this type of model for estimating the magnitudes and uncertainties of an arbitrary subset of unmeasured water-quality parameters given the measured complement of parameters historically measured at a U.S. Geological Survey streamgage. Water-quality data for 27 water-quality parameters from 596 discrete measureme
Authors
David J. Holtschlag
UFINCH: A method for simulating unit and daily flows in networks of channels described by NHDPlus using continuous flow data at U.S. Geological Survey streamgages
The UFINCH (Unit Flows In Networks of Channels) computer application can be used to simulate daily and unit flows in networks of streams based on geospatial data in the National Hydrography Dataset NHDPlus (with value added attributes), and U.S. Geoogical Survey daily streamflow data from a downstream (or base) streamgage. Among streamflow augmentation methods, UFINCH has the unique capability to
Authors
David J. Holtschlag
Estimating lag to peak between rainfall and peak streamflow with a mixed-effects model
We test the use of a mixed-effects model for estimating lag to peak for small basins in Maine (drainage areas from 0.8 to 78 km2). Lag to peak is defined as the time between the center of volume of the excess rainfall during a storm event and the resulting peak streamflow. A mixed-effects model allows for multiple observations at sites without violating model assumptions inherent in traditional or
Authors
Pamela J. Lombard, David Holtschlag
An evaluation of methods for estimating decadal stream loads
Effective management of water resources requires accurate information on the mass, or load of water-quality constituents transported from upstream watersheds to downstream receiving waters. Despite this need, no single method has been shown to consistently provide accurate load estimates among different water-quality constituents, sampling sites, and sampling regimes. We evaluate the accuracy of s
Authors
Casey J. Lee, Robert M. Hirsch, Gregory E. Schwarz, David J. Holtschlag, Stephen D. Preston, Charles G. Crawford, Aldo V. Vecchia
Estimation of monthly water yields and flows for 1951-2012 for the United States portion of the Great Lakes Basin with AFINCH
Monthly water yields from 105,829 catchments and corresponding flows in 107,691 stream segments were estimated for water years 1951–2012 in the Great Lakes Basin in the United States. Both sets of estimates were computed by using the Analysis of Flows In Networks of CHannels (AFINCH) application within the NHDPlus geospatial data framework. AFINCH provides an environment to develop constrained reg
Authors
Carol L. Luukkonen, David J. Holtschlag, Howard W. Reeves, Christopher J. Hoard, Lori M. Fuller
Comparison of streamflow and water-quality data collection techniques for the Saginaw River, Michigan
In 2009, the Michigan Department of Environmental Quality and the U.S. Geological Survey developed a plan to compare the effect of various streamgaging and water-quality collection techniques on streamflow and stream water-quality data for the Saginaw River, Michigan. The Saginaw River is the primary contributor of surface runoff to Saginaw Bay, Lake Huron, draining approximately 70 percent of the
Authors
C. J. Hoard, D. J. Holtschlag, J.W. Duris, D.A. James, D.J. Obenauer
Use of instantaneous streamflow measurements to improve regression estimates of index flow for the summer month of lowest streamflow in Michigan
In Michigan, index flow Q50 is a streamflow characteristic defined as the minimum of median flows for July, August, and September. The state of Michigan uses index flow estimates to help regulate large (greater than 100,000 gallons per day) water withdrawals to prevent adverse effects on characteristic fish populations. At sites where long-term streamgages are located, index flows are computed dir
Authors
David J. Holtschlag
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-regression techni
Authors
G. F. Koltun, David J. Holtschlag
Application guide for AFINCH (Analysis of Flows in Networks of Channels) described by NHDPlus
AFINCH (Analysis of Flows in Networks of CHannels) is a computer application that can be used to generate a time series of monthly flows at stream segments (flowlines) and water yields for catchments defined in the National Hydrography Dataset Plus (NHDPlus) value-added attribute system. AFINCH provides a basis for integrating monthly flow data from streamgages, water-use data, monthly climatic da
Authors
David J. Holtschlag
An initial investigation of multidimensional flow and transverse mixing characteristics of the Ohio River near Cincinnati, Ohio
Two-dimensional hydrodynamic and transport models were applied to a 34-mile reach of the Ohio River from Cincinnati, Ohio, upstream to Meldahl Dam near Neville, Ohio. The hydrodynamic model was based on the generalized finite-element hydrodynamic code RMA2 to simulate depth-averaged velocities and flow depths. The generalized water-quality transport code RMA4 was applied to simulate the transport
Authors
David J. Holtschlag
UFINCH— A Method for Simulating Unit and Daily Flows in Networks of Channels Described by NHDPlus Using Continuous Flow Data at USGS Streamgages
The computer program UFINCH (Unit Flows in Networks of Channels) can be used to simulate unit (15-minute) flows in a network of streams defined within the medium resolution National Hydrography Dataset Plus with value added attributes (NHDPlus, v. 2).
Analysis of Flows in Networks of Channels (AFINCH)
AFINCH (Analysis of Flows in Networks of CHannels) is a computer application designed to generate time series of monthly flows at stream segments and corresponding water yields at catchments defined in the National Hydrography Dataset (NHDPlus, v. 2).
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government