Randall J Hunt, Ph.D. (Former Employee)
Science and Products
Integrated Water Availability Assessments Fundamentals
The USGS Water Resources Mission Area is assessing how much water is available for human and ecological needs in the United States and identifying where and when the Nation may have challenges meeting its demand for water.
TC Chamberlin Modeling Center
The TC Chamberlin Modeling Center provides one-stop access to advanced computing so no project is limited by a lack of computer power. The Center can provide hardware access, assistance with migration and implementation, and training. We also develop, test, and disseminate state-of-the-art computational and analytical techniques and tools so models can be more effectively used in decision-making.
PEST++: A Parameter ESTimation code optimized for large environmental models
The PEST++ software suite is object-oriented universal computer code written in C++ that expands on and extends the algorithms included in PEST, a widely used parameter estimation code written in Fortran. PEST++ is designed to lower the barriers of entry for users and developers while providing efficient algorithms that can accommodate large, highly parameterized problems.
PESTCommander: A graphical user interface for file and run management across networks
PESTCommander is an object-oriented Graphical User Interface (GUI) written in Python® that facilitates the management of model files ("file management") and remote launching and termination of slave computers across a distributed network of computers ("run management").
GENIE: A general model-independent TCP/IP run manager
GENIE is a model-independent suite of programs that can be used to generally distribute, manage, and execute multiple model runs via the TCP/IP infrastructure. The suite consists of a file distribution interface, a run manage, a run executer, and a routine that can be compiled as part of a program and used to exchange model runs with the run manager.
Water, Energy, and Biogeochemical Budgets (WEBB): Trout Lake
USGS initiated the Water, Energy, and Biogeochemical Budgets (WEBB) program to understand the processes controlling water, energy, and biogeochemical fluxes over a range of temporal and spatial scales, and the effects of atmospheric and climatic variables. Trout Lake is one of five small, geographically and ecologically diverse watersheds representing a range of hydrologic and climatic conditions.
MODFLOW-NWT models and calibration files for the Mississippi Alluvial Plain, USA MODFLOW-NWT models and calibration files for the Mississippi Alluvial Plain, USA
The existing three-dimensional groundwater flow model (MODFLOW-2005) of the Mississippi Embayment Regional Aquifer system (MERAS), South-Central United States, was updated with: 1) higher stream density; 2) more spatially refined recharge; 3) better estimates of water use; 4) more recent time period simulated; 5) more realistic storage conceptualization; and 6) more robust handling of...
MODFLOW-NWT and MT3D-USGS models for appraising parameter sensitivity and other controlling factors in a synthetic watershed accounting for variably-saturated flow processes MODFLOW-NWT and MT3D-USGS models for appraising parameter sensitivity and other controlling factors in a synthetic watershed accounting for variably-saturated flow processes
A 3-dimensional (3D) synthetic model, using MODFLOW-NWT and MT3D-USGS, explores the new unsaturated zone heat transport capabilities in MT3D-USGS. Model simulations were used to explore various parameter sensitivities and unsaturated zone thicknesses and their impact on heat transport as water enters the subsurface as infiltration, flows through the unsaturated zone to the water table...
MODFLOW-NWT and MT3D-USGS models for evaluating heat flows, lags and dampening under high emission climate forcing for unsaturated/saturated transport in a synthetic watershed MODFLOW-NWT and MT3D-USGS models for evaluating heat flows, lags and dampening under high emission climate forcing for unsaturated/saturated transport in a synthetic watershed
A 3-dimensional (3D) synthetic model, built for running with MODFLOW-NWT and MT3D-USGS, explores the new unsaturated zone heat transport capabilities in MT3D-USGS. Model simulations explore potential responses to within a watershed to climate warming along system pathways. The response analysis uses output from a 30-year warming period on a synthetic watershed patterned after a humid...
MODFLOW-NWT, MT3D-USGS, and VS2DH models of 6 hypothetical 1-dimensional variably saturated systems to demonstrate the accuracy of new heat transport capabilities in MT3D-USGS MODFLOW-NWT, MT3D-USGS, and VS2DH models of 6 hypothetical 1-dimensional variably saturated systems to demonstrate the accuracy of new heat transport capabilities in MT3D-USGS
Six hypothetical 1-dimensional models are used to verify and demonstrate new unsaturated-zone heat transport functionality added to MT3D-USGS (version 1.1.0). Because the governing equations describing groundwater solute transport and heat transport have a similar form, MT3D-USGS may be applied to heat transport problems. Published examples of MT3DMS, from which MT3D-USGS is derived, as...
Airborne Electromagnetic (AEM) Survey in Southwest and Southeast Areas, Wisconsin, 2022 Airborne Electromagnetic (AEM) Survey in Southwest and Southeast Areas, Wisconsin, 2022
Airborne electromagnetic (AEM) and magnetic survey data were collected during March 2022 over a distance of 2,574.6 line kilometers in southeast and southwest Wisconsin. These data were collected in support of an effort to improve estimates of depth to bedrock through a collaborative project between the U.S. Geological Survey (USGS), Wisconsin Department of Agriculture, Trade, and...
MODFLOW-NWT simulations of regional groundwater flow under mining and pre-mining scenarios near the Mesabi Iron Range within the St. Louis River Basin, northeastern Minnesota MODFLOW-NWT simulations of regional groundwater flow under mining and pre-mining scenarios near the Mesabi Iron Range within the St. Louis River Basin, northeastern Minnesota
The U.S. Geological Survey developed two steady-state finite-difference regional groundwater-flow models using the MODFLOW-NWT computer code. These models simulate flow in the area of historical iron mining on and around the portion of the Mesabi Iron Range that is in the St. Louis River basin in northeastern Minnesota. The models are composed of 8 layers each; the upper four...
Filter Total Items: 150
A model uncertainty quantification protocol for evaluating the value of observation data A model uncertainty quantification protocol for evaluating the value of observation data
The history-matching approach to parameter estimation with models enables a powerful offshoot analysis of data worth—using the uncertainty of a model forecast as a metric for the worth of data. Adding observation data will either have no impact on forecast uncertainty or will reduce it. Removing existing data will either have no impact on forecast uncertainty or will increase it. The...
Authors
Michael N. Fienen, Laura A. Schachter, Randall J. Hunt
Temporally dense monitoring of pathogen occurrence at four drinking-water well sites – Insights and Implications Temporally dense monitoring of pathogen occurrence at four drinking-water well sites – Insights and Implications
Yearlong, event based, microbiological and chemical sampling was conducted at four public water supply well sites spanning a range of geologic settings and well depths to look for correlation between precipitation events and microbial occurrence. Near-continuous monitoring using autosamplers occurred just before, during, and after 5–7 sampling events triggered by rainfall and/or snowmelt
Authors
James F. Walsh, Randall J. Hunt, Anita C. Anderson, David W. Owens, Nancy Rice
Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal
Effective management of invasive species benefits from a comprehensive understanding of the species’ behavior and interactions with the invaded system. We investigated temporal dynamics of telemetry detections and the potential utility of a traitor approach for informing response efforts to the invasive grass carp (Ctenopharyngodon idella) population in the Sandusky River, a major...
Authors
Matthew Ross Acre, Tyler Michael Hessler, Sophia Marie Bonjour, James Roberts, Scott F. Colborne, Travis O. Brenden, Lucas R. Nathan, Dustin Broaddus, Christopher S. Vandergoot, Christine M. Mayer, Song S. Qian, Robert D. Hunter, Ryan E. Brown, Robin D. Calfee
Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta
The Mississippi Alluvial Plain has become one of the most important agricultural regions in the United States but relies heavily on groundwater for irrigation. On average, more than 12 billion gallons are withdrawn daily from the Mississippi River Valley alluvial aquifer. Declining groundwater levels, especially in the Delta region of northwest Mississippi and the Cache and Grand Prairie...
Authors
Andrew T. Leaf, Leslie L. Duncan, Connor J. Haugh, Randall J. Hunt, James R. Rigby
Effects of auto-adaptive localization on a model calibration using ensemble methods Effects of auto-adaptive localization on a model calibration using ensemble methods
Simulations of the natural systems for environmental decision-making typically benefit from a highly parameterized approach (Hunt et al. 2007; Doherty and Hunt 2010), which enhances the flow of information contained in state observations to the parameters and improves application to decision support. However, parameter estimation (PE) with highly parameterized environmental models using
Authors
Jonathan P. Traylor, Randall J. Hunt, Jeremy White, Michael N. Fienen
New capabilities in MT3D-USGS for simulating unsaturated-zone heat transport New capabilities in MT3D-USGS for simulating unsaturated-zone heat transport
Changes in climate and land use will alter groundwater heat transport dynamics in the future. These changes will in turn affect watershed processes (e.g., nutrient cycling) as well as watershed characteristics (e.g., distribution and persistence of cold-water habitat). Thus, groundwater flow and heat transport models at watershed scales that can characterize and quantify thermal impacts...
Authors
Eric D. Morway, Daniel T. Feinstein, Randall J. Hunt, Richard W. Healy
Non-USGS Publications**
Abrams, D.B., Haitjema, H.M., Feinstein, D.T. and Hunt, R.J., 2015, Field test of a Hybrid Finite-Difference and Analytic Element regional model. Groundwater. doi: 10.1111/gwat.12319.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
NWTOPT NWTOPT
Hyperparameter optimization approaches were applied to improve performance and accuracy of groundwater flow models. Freely available new software, NWTOPT, is described that uses Tree of Parzen Estimators (TPE) and Random Search optimization algorithms to optimize MODFLOW-NWT’s solver settings. We ran 3500 trials on a steady-state and transient model. To quantify the performance of...
PESTCommander PESTCommander
PESTCommander is an object-oriented Graphical User Interface (GUI) written in Python® that facilitates the management of model files ("file management") and remote launching and termination of slave computers across a distributed network of computers ("run management").
GENIE Version 2: A general model-independent TCP/IP run manager GENIE Version 2: A general model-independent TCP/IP run manager
GENIE Version 2 is a model-independent suite of programs that can be used to generally distribute, manage, and execute multiple model runs via a TCP/IP network. The suite consists of a file distribution interface, a run manager, a run executer, and a routine that can be compiled as part of a program and used to exchange model runs with the run manager.
Science and Products
Integrated Water Availability Assessments Fundamentals
The USGS Water Resources Mission Area is assessing how much water is available for human and ecological needs in the United States and identifying where and when the Nation may have challenges meeting its demand for water.
TC Chamberlin Modeling Center
The TC Chamberlin Modeling Center provides one-stop access to advanced computing so no project is limited by a lack of computer power. The Center can provide hardware access, assistance with migration and implementation, and training. We also develop, test, and disseminate state-of-the-art computational and analytical techniques and tools so models can be more effectively used in decision-making.
PEST++: A Parameter ESTimation code optimized for large environmental models
The PEST++ software suite is object-oriented universal computer code written in C++ that expands on and extends the algorithms included in PEST, a widely used parameter estimation code written in Fortran. PEST++ is designed to lower the barriers of entry for users and developers while providing efficient algorithms that can accommodate large, highly parameterized problems.
PESTCommander: A graphical user interface for file and run management across networks
PESTCommander is an object-oriented Graphical User Interface (GUI) written in Python® that facilitates the management of model files ("file management") and remote launching and termination of slave computers across a distributed network of computers ("run management").
GENIE: A general model-independent TCP/IP run manager
GENIE is a model-independent suite of programs that can be used to generally distribute, manage, and execute multiple model runs via the TCP/IP infrastructure. The suite consists of a file distribution interface, a run manage, a run executer, and a routine that can be compiled as part of a program and used to exchange model runs with the run manager.
Water, Energy, and Biogeochemical Budgets (WEBB): Trout Lake
USGS initiated the Water, Energy, and Biogeochemical Budgets (WEBB) program to understand the processes controlling water, energy, and biogeochemical fluxes over a range of temporal and spatial scales, and the effects of atmospheric and climatic variables. Trout Lake is one of five small, geographically and ecologically diverse watersheds representing a range of hydrologic and climatic conditions.
MODFLOW-NWT models and calibration files for the Mississippi Alluvial Plain, USA MODFLOW-NWT models and calibration files for the Mississippi Alluvial Plain, USA
The existing three-dimensional groundwater flow model (MODFLOW-2005) of the Mississippi Embayment Regional Aquifer system (MERAS), South-Central United States, was updated with: 1) higher stream density; 2) more spatially refined recharge; 3) better estimates of water use; 4) more recent time period simulated; 5) more realistic storage conceptualization; and 6) more robust handling of...
MODFLOW-NWT and MT3D-USGS models for appraising parameter sensitivity and other controlling factors in a synthetic watershed accounting for variably-saturated flow processes MODFLOW-NWT and MT3D-USGS models for appraising parameter sensitivity and other controlling factors in a synthetic watershed accounting for variably-saturated flow processes
A 3-dimensional (3D) synthetic model, using MODFLOW-NWT and MT3D-USGS, explores the new unsaturated zone heat transport capabilities in MT3D-USGS. Model simulations were used to explore various parameter sensitivities and unsaturated zone thicknesses and their impact on heat transport as water enters the subsurface as infiltration, flows through the unsaturated zone to the water table...
MODFLOW-NWT and MT3D-USGS models for evaluating heat flows, lags and dampening under high emission climate forcing for unsaturated/saturated transport in a synthetic watershed MODFLOW-NWT and MT3D-USGS models for evaluating heat flows, lags and dampening under high emission climate forcing for unsaturated/saturated transport in a synthetic watershed
A 3-dimensional (3D) synthetic model, built for running with MODFLOW-NWT and MT3D-USGS, explores the new unsaturated zone heat transport capabilities in MT3D-USGS. Model simulations explore potential responses to within a watershed to climate warming along system pathways. The response analysis uses output from a 30-year warming period on a synthetic watershed patterned after a humid...
MODFLOW-NWT, MT3D-USGS, and VS2DH models of 6 hypothetical 1-dimensional variably saturated systems to demonstrate the accuracy of new heat transport capabilities in MT3D-USGS MODFLOW-NWT, MT3D-USGS, and VS2DH models of 6 hypothetical 1-dimensional variably saturated systems to demonstrate the accuracy of new heat transport capabilities in MT3D-USGS
Six hypothetical 1-dimensional models are used to verify and demonstrate new unsaturated-zone heat transport functionality added to MT3D-USGS (version 1.1.0). Because the governing equations describing groundwater solute transport and heat transport have a similar form, MT3D-USGS may be applied to heat transport problems. Published examples of MT3DMS, from which MT3D-USGS is derived, as...
Airborne Electromagnetic (AEM) Survey in Southwest and Southeast Areas, Wisconsin, 2022 Airborne Electromagnetic (AEM) Survey in Southwest and Southeast Areas, Wisconsin, 2022
Airborne electromagnetic (AEM) and magnetic survey data were collected during March 2022 over a distance of 2,574.6 line kilometers in southeast and southwest Wisconsin. These data were collected in support of an effort to improve estimates of depth to bedrock through a collaborative project between the U.S. Geological Survey (USGS), Wisconsin Department of Agriculture, Trade, and...
MODFLOW-NWT simulations of regional groundwater flow under mining and pre-mining scenarios near the Mesabi Iron Range within the St. Louis River Basin, northeastern Minnesota MODFLOW-NWT simulations of regional groundwater flow under mining and pre-mining scenarios near the Mesabi Iron Range within the St. Louis River Basin, northeastern Minnesota
The U.S. Geological Survey developed two steady-state finite-difference regional groundwater-flow models using the MODFLOW-NWT computer code. These models simulate flow in the area of historical iron mining on and around the portion of the Mesabi Iron Range that is in the St. Louis River basin in northeastern Minnesota. The models are composed of 8 layers each; the upper four...
Filter Total Items: 150
A model uncertainty quantification protocol for evaluating the value of observation data A model uncertainty quantification protocol for evaluating the value of observation data
The history-matching approach to parameter estimation with models enables a powerful offshoot analysis of data worth—using the uncertainty of a model forecast as a metric for the worth of data. Adding observation data will either have no impact on forecast uncertainty or will reduce it. Removing existing data will either have no impact on forecast uncertainty or will increase it. The...
Authors
Michael N. Fienen, Laura A. Schachter, Randall J. Hunt
Temporally dense monitoring of pathogen occurrence at four drinking-water well sites – Insights and Implications Temporally dense monitoring of pathogen occurrence at four drinking-water well sites – Insights and Implications
Yearlong, event based, microbiological and chemical sampling was conducted at four public water supply well sites spanning a range of geologic settings and well depths to look for correlation between precipitation events and microbial occurrence. Near-continuous monitoring using autosamplers occurred just before, during, and after 5–7 sampling events triggered by rainfall and/or snowmelt
Authors
James F. Walsh, Randall J. Hunt, Anita C. Anderson, David W. Owens, Nancy Rice
Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal
Effective management of invasive species benefits from a comprehensive understanding of the species’ behavior and interactions with the invaded system. We investigated temporal dynamics of telemetry detections and the potential utility of a traitor approach for informing response efforts to the invasive grass carp (Ctenopharyngodon idella) population in the Sandusky River, a major...
Authors
Matthew Ross Acre, Tyler Michael Hessler, Sophia Marie Bonjour, James Roberts, Scott F. Colborne, Travis O. Brenden, Lucas R. Nathan, Dustin Broaddus, Christopher S. Vandergoot, Christine M. Mayer, Song S. Qian, Robert D. Hunter, Ryan E. Brown, Robin D. Calfee
Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta Simulating groundwater flow in the Mississippi Alluvial Plain with a focus on the Mississippi Delta
The Mississippi Alluvial Plain has become one of the most important agricultural regions in the United States but relies heavily on groundwater for irrigation. On average, more than 12 billion gallons are withdrawn daily from the Mississippi River Valley alluvial aquifer. Declining groundwater levels, especially in the Delta region of northwest Mississippi and the Cache and Grand Prairie...
Authors
Andrew T. Leaf, Leslie L. Duncan, Connor J. Haugh, Randall J. Hunt, James R. Rigby
Effects of auto-adaptive localization on a model calibration using ensemble methods Effects of auto-adaptive localization on a model calibration using ensemble methods
Simulations of the natural systems for environmental decision-making typically benefit from a highly parameterized approach (Hunt et al. 2007; Doherty and Hunt 2010), which enhances the flow of information contained in state observations to the parameters and improves application to decision support. However, parameter estimation (PE) with highly parameterized environmental models using
Authors
Jonathan P. Traylor, Randall J. Hunt, Jeremy White, Michael N. Fienen
New capabilities in MT3D-USGS for simulating unsaturated-zone heat transport New capabilities in MT3D-USGS for simulating unsaturated-zone heat transport
Changes in climate and land use will alter groundwater heat transport dynamics in the future. These changes will in turn affect watershed processes (e.g., nutrient cycling) as well as watershed characteristics (e.g., distribution and persistence of cold-water habitat). Thus, groundwater flow and heat transport models at watershed scales that can characterize and quantify thermal impacts...
Authors
Eric D. Morway, Daniel T. Feinstein, Randall J. Hunt, Richard W. Healy
Non-USGS Publications**
Abrams, D.B., Haitjema, H.M., Feinstein, D.T. and Hunt, R.J., 2015, Field test of a Hybrid Finite-Difference and Analytic Element regional model. Groundwater. doi: 10.1111/gwat.12319.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
NWTOPT NWTOPT
Hyperparameter optimization approaches were applied to improve performance and accuracy of groundwater flow models. Freely available new software, NWTOPT, is described that uses Tree of Parzen Estimators (TPE) and Random Search optimization algorithms to optimize MODFLOW-NWT’s solver settings. We ran 3500 trials on a steady-state and transient model. To quantify the performance of...
PESTCommander PESTCommander
PESTCommander is an object-oriented Graphical User Interface (GUI) written in Python® that facilitates the management of model files ("file management") and remote launching and termination of slave computers across a distributed network of computers ("run management").
GENIE Version 2: A general model-independent TCP/IP run manager GENIE Version 2: A general model-independent TCP/IP run manager
GENIE Version 2 is a model-independent suite of programs that can be used to generally distribute, manage, and execute multiple model runs via a TCP/IP network. The suite consists of a file distribution interface, a run manager, a run executer, and a routine that can be compiled as part of a program and used to exchange model runs with the run manager.
*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