Christopher T Green, Ph.D.
Christopher Green is a Research Hydrologist with the USGS Water Resources Mission Area.
Research Interests
- Flow and reactive transport in complex geological media
- Nitrogen cycling and fluxes in groundwater in agricultural areas
- Flow and solute transport in the unsaturated zone
- Gas transport in the unsaturated zone
- Effects of biofuels crops on groundwater quality
Science and Products
Compiled age tracer and redox chemistry data for the State of Wisconsin, 1987-2009 Compiled age tracer and redox chemistry data for the State of Wisconsin, 1987-2009
This data set was compiled to support the development of a model of oxygen reduction rates in Wisconsin groundwater wells; a model which is part of a Groundwater Nitrate Decision Support Tool for Wisconsin. Data were compiled from previously published studies with data collection from 1987 to 2009. Only data describing redox condition, groundwater age, depth to water, and well...
Data to support a Groundwater Nitrate Decision Support Tool for Wisconsin Data to support a Groundwater Nitrate Decision Support Tool for Wisconsin
A Groundwater Nitrate Decision Support Tool (GW-NDST) for wells in Wisconsin was developed to assist resource managers with assessing how legacy and possible future nitrate leaching rates, combined with groundwater lag times and potential denitrification, influence nitrate concentrations in wells (Juckem et al. 2024). Running and using the GW-NDST software involves downloading the...
NO3GWT version 1.0.0 NO3GWT version 1.0.0
A groundwater Nitrate Decision Support Tool (GW-NDST) for wells in Wisconsin was developed to assist resource managers with assessing how legacy and possible future nitrate leaching rates, combined with groundwater lag times and potential denitrification, influence nitrate concentrations in wells (Juckem et al. 2024). The GW-NDST was reviewed and approved by the journal via this official...
Soil sample data for four uranium mine sites, Mohave County, Arizona, April and November 2018 Soil sample data for four uranium mine sites, Mohave County, Arizona, April and November 2018
This U.S. Geological Survey data release is a spreadsheet containing soil-profile measurements of ambient spring and fall water-potential and water-content conditions, and physical and chemical properties for four mine sites, Mohave County, Arizona, April and November 2018. The four mines sampled in both April and November were Kanab North (native soil and reclaimed soil), EZ2 (native...
Data Release for Metamodeling and Mapping of Nitrate Flux in the Unsaturated Zone and Groundwater, Wisconsin, USA Data Release for Metamodeling and Mapping of Nitrate Flux in the Unsaturated Zone and Groundwater, Wisconsin, USA
Widespread nitrate contamination of groundwater in agricultural areas poses a major challenge to sustainable water resources. Efficient analysis of nitrate fluxes across large regions also remains difficult. This study introduces a method of characterizing nitrate transport processes continuously across regional unsaturated zones and groundwater based on surrogate, machine-learning...
Filter Total Items: 52
Design and calibration of a nitrate decision support tool for groundwater wells in Wisconsin, USA Design and calibration of a nitrate decision support tool for groundwater wells in Wisconsin, USA
This paper describes development of a nitrate decision support tool for groundwater wells (GW-NDST) that combines nitrate leaching and groundwater lag-times to compute well concentrations. The GW-NDST uses output from support models that simulate leached nitrate, groundwater age distributions, and nitrate reduction rates. The support models are linked through convolution to simulate...
Authors
Paul F. Juckem, Nicholas Corson-Dosch, Laura A. Schachter, Christopher Green, Kelsie M. Ferin, Eric G. Booth, Christopher J. Kucharik, Brian P. Austin, Leon J. Kauffman
Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses
This report describes scientific gaps that limit our ability to predict water-quality effects on water availability for beneficial uses across the United States. Water-quality constituents considered in the report include salinity, geogenic constituents, contaminants of emerging concern, and nitrogen. For each constituent, there is a selection of scientific gaps, approaches, and outcomes...
Knowledge gaps and opportunities in water-quality drivers of aquatic ecosystem health Knowledge gaps and opportunities in water-quality drivers of aquatic ecosystem health
This report identifies key scientific gaps that limit our ability to predict water quality effects on health of aquatic ecosystems and proposes approaches to address those gaps. Topics considered include (1) coupled nutrient-carbon cycle processes and related ecological-flow-regime drivers of ecosystem health, (2) anthropogenic and geogenic toxin bioexposure, (3) fine sediment drivers of...
Prioritizing river basins for nutrient studies Prioritizing river basins for nutrient studies
Increases in fluxes of nitrogen (N) and phosphorus (P) in the environment have led to negative impacts affecting drinking water, eutrophication, harmful algal blooms, climate change, and biodiversity loss. Because of the importance, scale, and complexity of these issues, it may be useful to consider methods for prioritizing nutrient research in representative drainage basins within a...
Authors
Anthony J. Tesoriero, Dale M. Robertson, Christopher Green, J.K. Bohlke, Judson Harvey, Sharon L. Qi
Long short-term memory models to quantify long-term evolution of streamflow discharge and groundwater depth in Alabama Long short-term memory models to quantify long-term evolution of streamflow discharge and groundwater depth in Alabama
Long short-term memory (LSTM) models have been shown to be efficient for rainfall-runoff modeling, and to a lesser extent, for groundwater depth forecasting. In this study, LSTMs were applied to quantify the spatiotemporal evolution of surface and subsurface hydrographs in Alabama in the Southeastern United States, where water sustainability has not been fully quantified across...
Authors
Hossein Gholizadeh, Yong Zhang, Jonathan Frame, Xiufen Gu, Christopher Green
Time-fractional flow equations (t-FFEs) to upscale transient groundwater flow characterized by temporally non-darcian flow due to medium heterogeneity Time-fractional flow equations (t-FFEs) to upscale transient groundwater flow characterized by temporally non-darcian flow due to medium heterogeneity
Upscaling groundwater flow is a fundamental challenge in hydrogeology. This study proposed time-fractional flow equations (t-FFEs) for upscaling long-term, transient groundwater flow and propagation of pressure heads in heterogeneous media. Monte Carlo simulations showed that, with increasing variance and correlation of the hydraulic conductivity (K), flow dynamics gradually deviated...
Authors
Yuan Xia, Yong Zhang, Christopher Green, Graham Fogg
Science and Products
Compiled age tracer and redox chemistry data for the State of Wisconsin, 1987-2009 Compiled age tracer and redox chemistry data for the State of Wisconsin, 1987-2009
This data set was compiled to support the development of a model of oxygen reduction rates in Wisconsin groundwater wells; a model which is part of a Groundwater Nitrate Decision Support Tool for Wisconsin. Data were compiled from previously published studies with data collection from 1987 to 2009. Only data describing redox condition, groundwater age, depth to water, and well...
Data to support a Groundwater Nitrate Decision Support Tool for Wisconsin Data to support a Groundwater Nitrate Decision Support Tool for Wisconsin
A Groundwater Nitrate Decision Support Tool (GW-NDST) for wells in Wisconsin was developed to assist resource managers with assessing how legacy and possible future nitrate leaching rates, combined with groundwater lag times and potential denitrification, influence nitrate concentrations in wells (Juckem et al. 2024). Running and using the GW-NDST software involves downloading the...
NO3GWT version 1.0.0 NO3GWT version 1.0.0
A groundwater Nitrate Decision Support Tool (GW-NDST) for wells in Wisconsin was developed to assist resource managers with assessing how legacy and possible future nitrate leaching rates, combined with groundwater lag times and potential denitrification, influence nitrate concentrations in wells (Juckem et al. 2024). The GW-NDST was reviewed and approved by the journal via this official...
Soil sample data for four uranium mine sites, Mohave County, Arizona, April and November 2018 Soil sample data for four uranium mine sites, Mohave County, Arizona, April and November 2018
This U.S. Geological Survey data release is a spreadsheet containing soil-profile measurements of ambient spring and fall water-potential and water-content conditions, and physical and chemical properties for four mine sites, Mohave County, Arizona, April and November 2018. The four mines sampled in both April and November were Kanab North (native soil and reclaimed soil), EZ2 (native...
Data Release for Metamodeling and Mapping of Nitrate Flux in the Unsaturated Zone and Groundwater, Wisconsin, USA Data Release for Metamodeling and Mapping of Nitrate Flux in the Unsaturated Zone and Groundwater, Wisconsin, USA
Widespread nitrate contamination of groundwater in agricultural areas poses a major challenge to sustainable water resources. Efficient analysis of nitrate fluxes across large regions also remains difficult. This study introduces a method of characterizing nitrate transport processes continuously across regional unsaturated zones and groundwater based on surrogate, machine-learning...
Filter Total Items: 52
Design and calibration of a nitrate decision support tool for groundwater wells in Wisconsin, USA Design and calibration of a nitrate decision support tool for groundwater wells in Wisconsin, USA
This paper describes development of a nitrate decision support tool for groundwater wells (GW-NDST) that combines nitrate leaching and groundwater lag-times to compute well concentrations. The GW-NDST uses output from support models that simulate leached nitrate, groundwater age distributions, and nitrate reduction rates. The support models are linked through convolution to simulate...
Authors
Paul F. Juckem, Nicholas Corson-Dosch, Laura A. Schachter, Christopher Green, Kelsie M. Ferin, Eric G. Booth, Christopher J. Kucharik, Brian P. Austin, Leon J. Kauffman
Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses Knowledge gaps and opportunities for understanding water-quality processes affecting water availability for beneficial uses
This report describes scientific gaps that limit our ability to predict water-quality effects on water availability for beneficial uses across the United States. Water-quality constituents considered in the report include salinity, geogenic constituents, contaminants of emerging concern, and nitrogen. For each constituent, there is a selection of scientific gaps, approaches, and outcomes...
Knowledge gaps and opportunities in water-quality drivers of aquatic ecosystem health Knowledge gaps and opportunities in water-quality drivers of aquatic ecosystem health
This report identifies key scientific gaps that limit our ability to predict water quality effects on health of aquatic ecosystems and proposes approaches to address those gaps. Topics considered include (1) coupled nutrient-carbon cycle processes and related ecological-flow-regime drivers of ecosystem health, (2) anthropogenic and geogenic toxin bioexposure, (3) fine sediment drivers of...
Prioritizing river basins for nutrient studies Prioritizing river basins for nutrient studies
Increases in fluxes of nitrogen (N) and phosphorus (P) in the environment have led to negative impacts affecting drinking water, eutrophication, harmful algal blooms, climate change, and biodiversity loss. Because of the importance, scale, and complexity of these issues, it may be useful to consider methods for prioritizing nutrient research in representative drainage basins within a...
Authors
Anthony J. Tesoriero, Dale M. Robertson, Christopher Green, J.K. Bohlke, Judson Harvey, Sharon L. Qi
Long short-term memory models to quantify long-term evolution of streamflow discharge and groundwater depth in Alabama Long short-term memory models to quantify long-term evolution of streamflow discharge and groundwater depth in Alabama
Long short-term memory (LSTM) models have been shown to be efficient for rainfall-runoff modeling, and to a lesser extent, for groundwater depth forecasting. In this study, LSTMs were applied to quantify the spatiotemporal evolution of surface and subsurface hydrographs in Alabama in the Southeastern United States, where water sustainability has not been fully quantified across...
Authors
Hossein Gholizadeh, Yong Zhang, Jonathan Frame, Xiufen Gu, Christopher Green
Time-fractional flow equations (t-FFEs) to upscale transient groundwater flow characterized by temporally non-darcian flow due to medium heterogeneity Time-fractional flow equations (t-FFEs) to upscale transient groundwater flow characterized by temporally non-darcian flow due to medium heterogeneity
Upscaling groundwater flow is a fundamental challenge in hydrogeology. This study proposed time-fractional flow equations (t-FFEs) for upscaling long-term, transient groundwater flow and propagation of pressure heads in heterogeneous media. Monte Carlo simulations showed that, with increasing variance and correlation of the hydraulic conductivity (K), flow dynamics gradually deviated...
Authors
Yuan Xia, Yong Zhang, Christopher Green, Graham Fogg