Randall J Hunt, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 150
Risk-based wellhead protection decision support: A repeatable workflow approach Risk-based wellhead protection decision support: A repeatable workflow approach
Environmental water management often benefits from a risk-based approach where information on the area of interest is characterized, assembled, and incorporated into a decision model considering uncertainty. This includes prior information from literature, field measurements, professional interpretation, and data assimilation resulting in a decision tool with a posterior uncertainty...
Authors
Michael N. Fienen, Nicholas Corson-Dosch, Jeremy T. White, Andrew T. Leaf, Randall J. Hunt
Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin
Background: Groundwater quality in the Silurian dolomite aquifer in northeastern Wisconsin, USA, has become contentious as dairy farms and exurban development expand.Objectives: We investigated private household wells in the region, determining the extent, sources, and risk factors of nitrate and microbial contamination.Methods: Total coliforms, Escherichia coli, and nitrate were...
Authors
Mark A. Borchardt, Joel P. Stokdyk, Burney A Kieke, Maureen A. Muldoon, Susan K. Spencer, Aaron D. Firnstahl, Davina Bonness, Randall J. Hunt, Tucker R. Burch
Evaluating lower computational burden approaches for calibration of large environmental models Evaluating lower computational burden approaches for calibration of large environmental models
Realistic environmental models used for decision making typically require a highly parameterized approach. Calibration of such models is computationally intensive because widely used parameter estimation approaches require individual forward runs for each parameter adjusted. These runs construct a parameter-to-observation sensitivity, or Jacobian, matrix used to develop candidate...
Authors
Randall J. Hunt, Jeremy T. White, Leslie L. Duncan, Connor J. Haugh, John E. Doherty
Approaches to highly parameterized inversion: PEST++ Version 5, a software suite for parameter estimation, uncertainty analysis, management optimization and sensitivity analysis Approaches to highly parameterized inversion: PEST++ Version 5, a software suite for parameter estimation, uncertainty analysis, management optimization and sensitivity analysis
PEST++ Version 5 extends and enhances the functionality of the PEST++ Version 3 software suite, providing environmental modeling practitioners access to updated Version 3 tools as well as new tools to support decision making with environmental models. Version 5 of PEST++ includes tools for global sensitivity analysis (PESTPP-SEN); least-squares parameter estimation with integrated first...
Authors
Jeremy T. White, Randall J. Hunt, Michael N. Fienen, John E. Doherty
Modeling water quality in watersheds: From here to the next generation Modeling water quality in watersheds: From here to the next generation
In this synthesis, we assess present research and anticipate future development needs in modeling water quality in watersheds. We first discuss areas of potential improvement in the representation of freshwater systems pertaining to water quality, including representation of environmental interfaces, in‐stream water quality and process interactions, soil health and land management, and...
Authors
Baihua Fu, J. S. Horsburgh, Anthony J. Jakeman, C Gaultieri, Todd W. Arnold, Lucy A. Marshall, Tim R Green, Nigel W. T. Quinn, Martin Volk, Randall J. Hunt, L. Vezzaro, Barry Croke, John Jakeman, Valerie O Snow, Brenda Rashleigh
Design and operations of the Hydrate 01 Stratigraphic test well, Alaska North Slope Design and operations of the Hydrate 01 Stratigraphic test well, Alaska North Slope
The National Energy Technology Laboratory, the Japan Oil, Gas and Metals National Corporation, and the U.S. Geological Survey are leading an effort to conduct an extended gas hydrate production test in northern Alaska. The proposed production test required the drilling of an initial stratigraphic test well (STW) to confirm the geologic conditions of the proposed test site. This well was...
Authors
Timothy S. Collett, Margarita V. Zyrianova, Norihiro Okinaka, Motoi Wakatsuki, Ray Boswell, Scott Marsteller, David Minge, Stephen Crumley, David Itter, Robert D. Hunter
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.
Science and Products
Filter Total Items: 150
Risk-based wellhead protection decision support: A repeatable workflow approach Risk-based wellhead protection decision support: A repeatable workflow approach
Environmental water management often benefits from a risk-based approach where information on the area of interest is characterized, assembled, and incorporated into a decision model considering uncertainty. This includes prior information from literature, field measurements, professional interpretation, and data assimilation resulting in a decision tool with a posterior uncertainty...
Authors
Michael N. Fienen, Nicholas Corson-Dosch, Jeremy T. White, Andrew T. Leaf, Randall J. Hunt
Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin
Background: Groundwater quality in the Silurian dolomite aquifer in northeastern Wisconsin, USA, has become contentious as dairy farms and exurban development expand.Objectives: We investigated private household wells in the region, determining the extent, sources, and risk factors of nitrate and microbial contamination.Methods: Total coliforms, Escherichia coli, and nitrate were...
Authors
Mark A. Borchardt, Joel P. Stokdyk, Burney A Kieke, Maureen A. Muldoon, Susan K. Spencer, Aaron D. Firnstahl, Davina Bonness, Randall J. Hunt, Tucker R. Burch
Evaluating lower computational burden approaches for calibration of large environmental models Evaluating lower computational burden approaches for calibration of large environmental models
Realistic environmental models used for decision making typically require a highly parameterized approach. Calibration of such models is computationally intensive because widely used parameter estimation approaches require individual forward runs for each parameter adjusted. These runs construct a parameter-to-observation sensitivity, or Jacobian, matrix used to develop candidate...
Authors
Randall J. Hunt, Jeremy T. White, Leslie L. Duncan, Connor J. Haugh, John E. Doherty
Approaches to highly parameterized inversion: PEST++ Version 5, a software suite for parameter estimation, uncertainty analysis, management optimization and sensitivity analysis Approaches to highly parameterized inversion: PEST++ Version 5, a software suite for parameter estimation, uncertainty analysis, management optimization and sensitivity analysis
PEST++ Version 5 extends and enhances the functionality of the PEST++ Version 3 software suite, providing environmental modeling practitioners access to updated Version 3 tools as well as new tools to support decision making with environmental models. Version 5 of PEST++ includes tools for global sensitivity analysis (PESTPP-SEN); least-squares parameter estimation with integrated first...
Authors
Jeremy T. White, Randall J. Hunt, Michael N. Fienen, John E. Doherty
Modeling water quality in watersheds: From here to the next generation Modeling water quality in watersheds: From here to the next generation
In this synthesis, we assess present research and anticipate future development needs in modeling water quality in watersheds. We first discuss areas of potential improvement in the representation of freshwater systems pertaining to water quality, including representation of environmental interfaces, in‐stream water quality and process interactions, soil health and land management, and...
Authors
Baihua Fu, J. S. Horsburgh, Anthony J. Jakeman, C Gaultieri, Todd W. Arnold, Lucy A. Marshall, Tim R Green, Nigel W. T. Quinn, Martin Volk, Randall J. Hunt, L. Vezzaro, Barry Croke, John Jakeman, Valerie O Snow, Brenda Rashleigh
Design and operations of the Hydrate 01 Stratigraphic test well, Alaska North Slope Design and operations of the Hydrate 01 Stratigraphic test well, Alaska North Slope
The National Energy Technology Laboratory, the Japan Oil, Gas and Metals National Corporation, and the U.S. Geological Survey are leading an effort to conduct an extended gas hydrate production test in northern Alaska. The proposed production test required the drilling of an initial stratigraphic test well (STW) to confirm the geologic conditions of the proposed test site. This well was...
Authors
Timothy S. Collett, Margarita V. Zyrianova, Norihiro Okinaka, Motoi Wakatsuki, Ray Boswell, Scott Marsteller, David Minge, Stephen Crumley, David Itter, Robert D. Hunter
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.
*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