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
Filter Total Items: 52
Predicting unsaturated zone nitrogen mass balances in agricultural settings of the United States Predicting unsaturated zone nitrogen mass balances in agricultural settings of the United States
Unsaturated zone N fate and transport were evaluated at four sites to identify the predominant pathways of N cycling: an almond [Prunus dulcis (Mill.) D.A. Webb] orchard and cornfield (Zea mays L.) in the lower Merced River study basin, California; and corn–soybean [Glycine max (L.) Merr.] rotations in study basins at Maple Creek, Nebraska, and at Morgan Creek, Maryland. We used inverse...
Authors
Bernard T. Nolan, Larry J. Puckett, Liwang Ma, Christopher T. Green, E. Randall Bayless, Robert W. Malone
Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer
Gradients in contaminant concentrations and isotopic compositions commonly are used to derive reaction parameters for natural attenuation in aquifers. Differences between field‐scale (apparent) estimated reaction rates and isotopic fractionations and local‐scale (intrinsic) effects are poorly understood for complex natural systems. For a heterogeneous alluvial fan aquifer, numerical...
Authors
Christopher T. Green, J.K. Bohlke, Barbara A. Bekins, Steven P. Phillips
Spatial and temporal trends in nitrate concentrations in the eastern San Joaquin Valley regional aquifer and implications for fertilizer management Spatial and temporal trends in nitrate concentrations in the eastern San Joaquin Valley regional aquifer and implications for fertilizer management
Ground-water withdrawals in the San Joaquin Valley totaled 64 million m3 /day (19 million ac-ft) in 2000, supplying about 45% of agricultural irrigation demand and about 80% of municipal supply (Hutson et al., 2004). Most of the population and ground-water use are in the eastern San Joaquin Valley, where reliance on ground water is expected to increase as a result of rapid population...
Authors
Karen R. Burow, Christopher T. Green
Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States
The ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers was investigated in four important agricultural settings in the United States. The study used laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) in the San Joaquin watershed, California, the Elkhorn...
Authors
C.T. Green, L.J. Puckett, J.K. Böhlke, B.A. Bekins, S.P. Phillips, L. J. Kauffman, J. M. Denver, H.M. Johnson
Nitrogen fluxes through unsaturated zones in five agricultural settings across the United States Nitrogen fluxes through unsaturated zones in five agricultural settings across the United States
The main physical and chemical controls on nitrogen (N) fluxes between the root zone and the water table were determined for agricultural sites in California, Indiana, Maryland, Nebraska, and Washington from 2004 to 2005. Sites included irrigated and nonirrigated fields; soil textures ranging from clay to sand; crops including corn, soybeans, almonds, and pasture; and unsaturated zone...
Authors
C.T. Green, L.H. Fisher, B.A. Bekins
Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California
The transport and fate of agricultural chemicals in a variety of environmental settings is being evaluated as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. One of the locations being evaluated is a 2,700-km2 (square kilometer) regional study area in the northeastern San Joaquin Valley surrounding the city of Modesto, an area dominated by irrigated...
Authors
Steven P. Phillips, Christopher T. Green, Karen R. Burow, Jennifer L. Shelton, Diane L. Rewis
Science and Products
Filter Total Items: 52
Predicting unsaturated zone nitrogen mass balances in agricultural settings of the United States Predicting unsaturated zone nitrogen mass balances in agricultural settings of the United States
Unsaturated zone N fate and transport were evaluated at four sites to identify the predominant pathways of N cycling: an almond [Prunus dulcis (Mill.) D.A. Webb] orchard and cornfield (Zea mays L.) in the lower Merced River study basin, California; and corn–soybean [Glycine max (L.) Merr.] rotations in study basins at Maple Creek, Nebraska, and at Morgan Creek, Maryland. We used inverse...
Authors
Bernard T. Nolan, Larry J. Puckett, Liwang Ma, Christopher T. Green, E. Randall Bayless, Robert W. Malone
Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer
Gradients in contaminant concentrations and isotopic compositions commonly are used to derive reaction parameters for natural attenuation in aquifers. Differences between field‐scale (apparent) estimated reaction rates and isotopic fractionations and local‐scale (intrinsic) effects are poorly understood for complex natural systems. For a heterogeneous alluvial fan aquifer, numerical...
Authors
Christopher T. Green, J.K. Bohlke, Barbara A. Bekins, Steven P. Phillips
Spatial and temporal trends in nitrate concentrations in the eastern San Joaquin Valley regional aquifer and implications for fertilizer management Spatial and temporal trends in nitrate concentrations in the eastern San Joaquin Valley regional aquifer and implications for fertilizer management
Ground-water withdrawals in the San Joaquin Valley totaled 64 million m3 /day (19 million ac-ft) in 2000, supplying about 45% of agricultural irrigation demand and about 80% of municipal supply (Hutson et al., 2004). Most of the population and ground-water use are in the eastern San Joaquin Valley, where reliance on ground water is expected to increase as a result of rapid population...
Authors
Karen R. Burow, Christopher T. Green
Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States Limited occurrence of denitrification in four shallow aquifers in agricultural areas of the United States
The ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers was investigated in four important agricultural settings in the United States. The study used laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) in the San Joaquin watershed, California, the Elkhorn...
Authors
C.T. Green, L.J. Puckett, J.K. Böhlke, B.A. Bekins, S.P. Phillips, L. J. Kauffman, J. M. Denver, H.M. Johnson
Nitrogen fluxes through unsaturated zones in five agricultural settings across the United States Nitrogen fluxes through unsaturated zones in five agricultural settings across the United States
The main physical and chemical controls on nitrogen (N) fluxes between the root zone and the water table were determined for agricultural sites in California, Indiana, Maryland, Nebraska, and Washington from 2004 to 2005. Sites included irrigated and nonirrigated fields; soil textures ranging from clay to sand; crops including corn, soybeans, almonds, and pasture; and unsaturated zone...
Authors
C.T. Green, L.H. Fisher, B.A. Bekins
Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California
The transport and fate of agricultural chemicals in a variety of environmental settings is being evaluated as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. One of the locations being evaluated is a 2,700-km2 (square kilometer) regional study area in the northeastern San Joaquin Valley surrounding the city of Modesto, an area dominated by irrigated...
Authors
Steven P. Phillips, Christopher T. Green, Karen R. Burow, Jennifer L. Shelton, Diane L. Rewis