David M Wolock, Ph.D.
David Wolock is a Supervisory Hydrologist with the USGS Water Resources Mission Area.
Science and Products
Filter Total Items: 13
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Filter Total Items: 127
Factors influencing ground-water recharge in the eastern United States
Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1 cm/yr, respectively) and more str
Authors
B. T. Nolan, R. W. Healy, P.E. Taber, K. Perkins, K.J. Hitt, D. M. Wolock
Regression model for explaining and predicting concentrations of Dieldrin in whole fish from United States streams
No abstract available.
Authors
Lisa H. Nowell, Charles G. Crawford, Naomi Nakagaki, Gail P. Thelin, David M. Wolock
Pesticides in the Nation's Streams and Ground Water, 1992–2001
This report is one of a series of publications, The Quality of Our Nation's Waters, that describe major findings of the NAWQA Program on water-quality issues of regional and national concern. This report presents evaluations of pesticides in streams and ground water based on findings for the first decadal cycle of NAWQA. 'Pesticides in the Nation's Streams and Ground Water, 1992-2001' greatly expa
Authors
Robert J. Gilliom, Jack E. Barbash, Charles G. Crawford, Pixie A. Hamilton, Jeffrey D. Martin, Naomi Nakagaki, Lisa H. Nowell, Jonathan C. Scott, Paul E. Stackelberg, Gail P. Thelin, David M. Wolock
Development and application of a regression equation for estimating the occurrence of atrazine in shallow ground water beneath agricultural areas of the United States
Results from 52 ground-water studies throughout the United States were used to examine relations between the occurrence of atrazine in shallow ground water in agricultural settings and explanatory variables that describe the natural setting, agricultural-management practices, and the type and amount of development in each area. The explanatory variables that were found to be correlated with atrazi
Authors
Paul E. Stackelberg, Robert J. Gilliom, David M. Wolock, Kerie J. Hitt
USGS Streamgages Linked to the Medium Resolution NHD
The locations of approximately 23,000 current and historical U.S. Geological Survey (USGS) streamgages in the United States and Puerto Rico (with the exception of Alaska) have been snapped to the medium resolution National Hydrography Dataset (NHD). The NHD contains geospatial information about mapped surface-water features, such as streams, lakes, and reservoirs, etc., creating a hydrologic netw
Authors
David W. Stewart, Alan Rea, David M. Wolock
Design of a national streamflow information program
No abstract available.
Authors
Jerad D. Bales, John E. Costa, David J. Holtschlag, Kenneth J. Lanfear, Stephen Lipscomb, Paul C.D. Milly, Roland J. Viger, David M. Wolock
Estimation of agricultural pesticide use in drainage basins using land cover maps and county pesticide data
A geographic information system (GIS) was used to estimate agricultural pesticide use in the drainage basins of streams that are studied as part of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. Drainage basin pesticide use estimates were computed by intersecting digital maps of drainage basin boundaries with an enhanced version of the National Land Cover Data 1992
Authors
Naomi Nakagaki, David M. Wolock
Estimates of Flow Duration, Mean Flow, and Peak-Discharge Frequency Values for Kansas Stream Locations
Streamflow statistics of flow duration and peak-discharge frequency were estimated for 4,771 individual locations on streams listed on the 1999 Kansas Surface Water Register. These statistics included the flow-duration values of 90, 75, 50, 25, and 10 percent, as well as the mean flow value. Peak-discharge frequency values were estimated for the 2-, 5-, 10-, 25-, 50-, and 100-year floods.
Least
Authors
Charles A. Perry, David M. Wolock, Joshua C. Artman
Estimates of median flows for streams on the 1999 Kansas Surface Water Register
The Kansas State Legislature, by enacting Kansas Statute KSA 82a?2001 et. seq., mandated the criteria for determining which Kansas stream segments would be subject to classification by the State. One criterion for the selection as a classified stream segment is based on the statistic of median flow being equal to or greater than 1 cubic foot per second. As specified by KSA 82a?2001 et. seq., media
Authors
Charles A. Perry, David M. Wolock, Joshua C. Artman
Delineation and evaluation of hydrologic-landscape regions in the United States using geographic information system tools and multivariate statistical analyses.
Hydrologic-landscape regions in the United States were delineated by using geographic information system (GIS) tools combined with principal components and cluster analyses. The GIS and statistical analyses were applied to land-surface form, geologic texture (permeability of the soil and bedrock), and climate variables that describe the physical and climatic setting of 43,931 small (approximately
Authors
David M. Wolock, Thomas C. Winter, Gerard McMahon
Estimated mean annual natural ground-water recharge in the conterminous United States
This 1-kilometer resolution raster (grid) dataset is an index of mean annual natural ground-water recharge. The dataset was created by multiplying a grid of base-flow index (BFI) values by a grid of mean annual runoff values derived from a 1951-80 mean annual runoff contour map. Mean annual runoff is long-term average streamflow expressed on a per-unit-area basis.
Authors
David M. Wolock
Infiltration-Excess Overland Flow Estimated by TOPMODEL for the Conterminous United States
This 5-kilometer resolution raster (grid) dataset for the conterminous United States represents the average percentage of infiltration-excess overland flow in total streamflow estimated by the watershed model TOPMODEL. Infiltration-excess overland flow is simulated in TOPMODEL as precipitation that exceeds the infiltration capacity of the soil and enters the stream channel.
Authors
David M. Wolock
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 127
Factors influencing ground-water recharge in the eastern United States
Ground-water recharge estimates for selected locations in the eastern half of the United States were obtained by Darcian and chloride-tracer methods and compared using statistical analyses. Recharge estimates derived from unsaturated-zone (RUZC) and saturated-zone (RSZC) chloride mass balance methods are less variable (interquartile ranges or IQRs are 9.5 and 16.1 cm/yr, respectively) and more str
Authors
B. T. Nolan, R. W. Healy, P.E. Taber, K. Perkins, K.J. Hitt, D. M. Wolock
Regression model for explaining and predicting concentrations of Dieldrin in whole fish from United States streams
No abstract available.
Authors
Lisa H. Nowell, Charles G. Crawford, Naomi Nakagaki, Gail P. Thelin, David M. Wolock
Pesticides in the Nation's Streams and Ground Water, 1992–2001
This report is one of a series of publications, The Quality of Our Nation's Waters, that describe major findings of the NAWQA Program on water-quality issues of regional and national concern. This report presents evaluations of pesticides in streams and ground water based on findings for the first decadal cycle of NAWQA. 'Pesticides in the Nation's Streams and Ground Water, 1992-2001' greatly expa
Authors
Robert J. Gilliom, Jack E. Barbash, Charles G. Crawford, Pixie A. Hamilton, Jeffrey D. Martin, Naomi Nakagaki, Lisa H. Nowell, Jonathan C. Scott, Paul E. Stackelberg, Gail P. Thelin, David M. Wolock
Development and application of a regression equation for estimating the occurrence of atrazine in shallow ground water beneath agricultural areas of the United States
Results from 52 ground-water studies throughout the United States were used to examine relations between the occurrence of atrazine in shallow ground water in agricultural settings and explanatory variables that describe the natural setting, agricultural-management practices, and the type and amount of development in each area. The explanatory variables that were found to be correlated with atrazi
Authors
Paul E. Stackelberg, Robert J. Gilliom, David M. Wolock, Kerie J. Hitt
USGS Streamgages Linked to the Medium Resolution NHD
The locations of approximately 23,000 current and historical U.S. Geological Survey (USGS) streamgages in the United States and Puerto Rico (with the exception of Alaska) have been snapped to the medium resolution National Hydrography Dataset (NHD). The NHD contains geospatial information about mapped surface-water features, such as streams, lakes, and reservoirs, etc., creating a hydrologic netw
Authors
David W. Stewart, Alan Rea, David M. Wolock
Design of a national streamflow information program
No abstract available.
Authors
Jerad D. Bales, John E. Costa, David J. Holtschlag, Kenneth J. Lanfear, Stephen Lipscomb, Paul C.D. Milly, Roland J. Viger, David M. Wolock
Estimation of agricultural pesticide use in drainage basins using land cover maps and county pesticide data
A geographic information system (GIS) was used to estimate agricultural pesticide use in the drainage basins of streams that are studied as part of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. Drainage basin pesticide use estimates were computed by intersecting digital maps of drainage basin boundaries with an enhanced version of the National Land Cover Data 1992
Authors
Naomi Nakagaki, David M. Wolock
Estimates of Flow Duration, Mean Flow, and Peak-Discharge Frequency Values for Kansas Stream Locations
Streamflow statistics of flow duration and peak-discharge frequency were estimated for 4,771 individual locations on streams listed on the 1999 Kansas Surface Water Register. These statistics included the flow-duration values of 90, 75, 50, 25, and 10 percent, as well as the mean flow value. Peak-discharge frequency values were estimated for the 2-, 5-, 10-, 25-, 50-, and 100-year floods.
Least
Authors
Charles A. Perry, David M. Wolock, Joshua C. Artman
Estimates of median flows for streams on the 1999 Kansas Surface Water Register
The Kansas State Legislature, by enacting Kansas Statute KSA 82a?2001 et. seq., mandated the criteria for determining which Kansas stream segments would be subject to classification by the State. One criterion for the selection as a classified stream segment is based on the statistic of median flow being equal to or greater than 1 cubic foot per second. As specified by KSA 82a?2001 et. seq., media
Authors
Charles A. Perry, David M. Wolock, Joshua C. Artman
Delineation and evaluation of hydrologic-landscape regions in the United States using geographic information system tools and multivariate statistical analyses.
Hydrologic-landscape regions in the United States were delineated by using geographic information system (GIS) tools combined with principal components and cluster analyses. The GIS and statistical analyses were applied to land-surface form, geologic texture (permeability of the soil and bedrock), and climate variables that describe the physical and climatic setting of 43,931 small (approximately
Authors
David M. Wolock, Thomas C. Winter, Gerard McMahon
Estimated mean annual natural ground-water recharge in the conterminous United States
This 1-kilometer resolution raster (grid) dataset is an index of mean annual natural ground-water recharge. The dataset was created by multiplying a grid of base-flow index (BFI) values by a grid of mean annual runoff values derived from a 1951-80 mean annual runoff contour map. Mean annual runoff is long-term average streamflow expressed on a per-unit-area basis.
Authors
David M. Wolock
Infiltration-Excess Overland Flow Estimated by TOPMODEL for the Conterminous United States
This 5-kilometer resolution raster (grid) dataset for the conterminous United States represents the average percentage of infiltration-excess overland flow in total streamflow estimated by the watershed model TOPMODEL. Infiltration-excess overland flow is simulated in TOPMODEL as precipitation that exceeds the infiltration capacity of the soil and enters the stream channel.
Authors
David M. Wolock