John T. Wilson (Former Employee)
Science and Products
Filter Total Items: 37
Using heat to characterize streambed water flux variability in four stream reaches Using heat to characterize streambed water flux variability in four stream reaches
Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the...
Authors
H.I. Essaid, C.M. Zamora, K. A. McCarthy, J. R. Vogel, J.T. Wilson
Transport and fate of nitrate at the ground-water/surface-water interface Transport and fate of nitrate at the ground-water/surface-water interface
Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic...
Authors
L.J. Puckett, C. Zamora, H. Essaid, J.T. Wilson, H.M. Johnson, M.J. Brayton, J. R. Vogel
Water and agricultural-chemical transport in a Midwestern, tile-drained watershed: Implications for conservation practices Water and agricultural-chemical transport in a Midwestern, tile-drained watershed: Implications for conservation practices
The study of agricultural chemicals is one of five national priority topics being addressed by the National Water-Quality Assessment (NAWQA) Program in its second decade of studies, which began in 2001. Seven watersheds across the Nation were selected for the NAWQA agricultural-chemical topical study. The watersheds selected represent a range of agricultural settings - with varying crop...
Authors
Nancy T. Baker, Wesley W. Stone, Jeffrey W. Frey, John T. Wilson
Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport
Agricultural subsurface drains, commonly referred to as tile drains, are potentially significant pathways for the movement of fertilizers and pesticides to streams and ditches in much of the Midwest. Preferential flow in the unsaturated zone provides a route for water and solutes to bypass the soil matrix and reach tile drains faster than predicted by traditional displacement theory...
Authors
W.W. Stone, J.T. Wilson
Occurrence and transport of agricultural chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04 Occurrence and transport of agricultural chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04
Leary Weber Ditch Basin, Hancock County, Indiana, is one of seven first-order basins selected from across the United States as part of the Agricultural Chemicals: Source, Transport, and Fate study conducted by the National Water-Quality Assessment Program of the U.S. Geological Survey. The nationwide study was designed to increase the understanding of the links between the sources of...
Authors
Nancy T. Baker, Wesley W. Stone, John T. Wilson, Michael T. Meyer
MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model -- GMG Linear Equation Solver Package Documentation MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model -- GMG Linear Equation Solver Package Documentation
A geometric multigrid solver (GMG), based in the preconditioned conjugate gradient algorithm, has been developed for solving systems of equations resulting from applying the cell-centered finite difference algorithm to flow in porous media. This solver has been adapted to the U.S. Geological Survey ground-water flow model MODFLOW-2000. The documentation herein is a description of the...
Authors
John D. Wilson, Richard L. Naff
Non-USGS Publications**
**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: 37
Using heat to characterize streambed water flux variability in four stream reaches Using heat to characterize streambed water flux variability in four stream reaches
Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the...
Authors
H.I. Essaid, C.M. Zamora, K. A. McCarthy, J. R. Vogel, J.T. Wilson
Transport and fate of nitrate at the ground-water/surface-water interface Transport and fate of nitrate at the ground-water/surface-water interface
Although numerous studies of hyporheic exchange and denitrification have been conducted in pristine, high-gradient streams, few studies of this type have been conducted in nutrient-rich, low-gradient streams. This is a particularly important subject given the interest in nitrogen (N) inputs to the Gulf of Mexico and other eutrophic aquatic systems. A combination of hydrologic...
Authors
L.J. Puckett, C. Zamora, H. Essaid, J.T. Wilson, H.M. Johnson, M.J. Brayton, J. R. Vogel
Water and agricultural-chemical transport in a Midwestern, tile-drained watershed: Implications for conservation practices Water and agricultural-chemical transport in a Midwestern, tile-drained watershed: Implications for conservation practices
The study of agricultural chemicals is one of five national priority topics being addressed by the National Water-Quality Assessment (NAWQA) Program in its second decade of studies, which began in 2001. Seven watersheds across the Nation were selected for the NAWQA agricultural-chemical topical study. The watersheds selected represent a range of agricultural settings - with varying crop...
Authors
Nancy T. Baker, Wesley W. Stone, Jeffrey W. Frey, John T. Wilson
Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport
Agricultural subsurface drains, commonly referred to as tile drains, are potentially significant pathways for the movement of fertilizers and pesticides to streams and ditches in much of the Midwest. Preferential flow in the unsaturated zone provides a route for water and solutes to bypass the soil matrix and reach tile drains faster than predicted by traditional displacement theory...
Authors
W.W. Stone, J.T. Wilson
Occurrence and transport of agricultural chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04 Occurrence and transport of agricultural chemicals in Leary Weber Ditch Basin, Hancock County, Indiana, 2003-04
Leary Weber Ditch Basin, Hancock County, Indiana, is one of seven first-order basins selected from across the United States as part of the Agricultural Chemicals: Source, Transport, and Fate study conducted by the National Water-Quality Assessment Program of the U.S. Geological Survey. The nationwide study was designed to increase the understanding of the links between the sources of...
Authors
Nancy T. Baker, Wesley W. Stone, John T. Wilson, Michael T. Meyer
MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model -- GMG Linear Equation Solver Package Documentation MODFLOW-2000, The U.S. Geological Survey Modular Ground-Water Model -- GMG Linear Equation Solver Package Documentation
A geometric multigrid solver (GMG), based in the preconditioned conjugate gradient algorithm, has been developed for solving systems of equations resulting from applying the cell-centered finite difference algorithm to flow in porous media. This solver has been adapted to the U.S. Geological Survey ground-water flow model MODFLOW-2000. The documentation herein is a description of the...
Authors
John D. Wilson, Richard L. Naff
Non-USGS Publications**
**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.