Gregory E Schwarz (Former Employee)
Science and Products
Filter Total Items: 68
A Preliminary SPARROW Model of Suspended Sediment for the Conterminous United States A Preliminary SPARROW Model of Suspended Sediment for the Conterminous United States
This report describes the results of a preliminary Spatially Referenced Regression on Watershed attributes (SPARROW) model of suspended sediment for the conterminous United States. The analysis is based on flux estimates compiled from more than 1,800 long-term monitoring stations operated by the U.S. Geological Survey (USGS) during the period 1975-2007. The SPARROW model is structured on...
Authors
Gregory E. Schwarz
Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin
Seasonal hypoxia in the northern Gulf of Mexico has been linked to increased nitrogen fluxes from the Mississippi and Atchafalaya River Basins, though recent evidence shows that phosphorus also influences productivity in the Gulf. We developed a spatially explicit and structurally detailed SPARROW water-quality model that reveals important differences in the sources and transport...
Authors
R. B. Alexander, R. A. Smith, G. E. Schwarz, E.W. Boyer, J.V. Nolan, J. W. Brakebill
Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003 Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003
This study focused on three areas that might be of interest to water-quality managers in the Pacific Northwest: (1) annual loads of total nitrogen (TN), total phosphorus (TP) and suspended sediment (SS) transported through the Columbia River and Puget Sound Basins, (2) annual yields of TN, TP, and SS relative to differences in landscape and climatic conditions between subbasin catchments...
Authors
Daniel R. Wise, Frank A. Rinella, Joseph F. Rinella, Greg J. Fuhrer, Sandra S. Embrey, Gregory M. Clark, Gregory E. Schwarz, Steven Sobieszczyk
The role of headwater streams in downstream water quality The role of headwater streams in downstream water quality
Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality...
Authors
R. B. Alexander, E.W. Boyer, R. A. Smith, G. E. Schwarz, R. B. Moore
Changes in streamflow and water quality in selected nontidal basins in the Chesapeake Bay Watershed, 1985-2004 Changes in streamflow and water quality in selected nontidal basins in the Chesapeake Bay Watershed, 1985-2004
As part of an annual evaluation of water-quality conditions by the Chesapeake Bay Program, water-quality and streamflow data from 32 sites in nontidal parts of the Chesapeake Bay watershed were analyzed to document annual nutrient and sediment trends for 1985 through 2004. This study also formalized different trend tests and methodologies used in assessing the effectiveness of man...
Authors
Michael J. Langland, Jeff P. Raffensperger, Douglas Moyer, Jurate M. Landwehr, Gregory E. Schwarz
Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation
SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds containing the stations. The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and diffuse...
Authors
Gregory Schwarz, Anne B. Hoos, R. B. Alexander, R. A. Smith
Science and Products
Filter Total Items: 68
A Preliminary SPARROW Model of Suspended Sediment for the Conterminous United States A Preliminary SPARROW Model of Suspended Sediment for the Conterminous United States
This report describes the results of a preliminary Spatially Referenced Regression on Watershed attributes (SPARROW) model of suspended sediment for the conterminous United States. The analysis is based on flux estimates compiled from more than 1,800 long-term monitoring stations operated by the U.S. Geological Survey (USGS) during the period 1975-2007. The SPARROW model is structured on...
Authors
Gregory E. Schwarz
Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi River Basin
Seasonal hypoxia in the northern Gulf of Mexico has been linked to increased nitrogen fluxes from the Mississippi and Atchafalaya River Basins, though recent evidence shows that phosphorus also influences productivity in the Gulf. We developed a spatially explicit and structurally detailed SPARROW water-quality model that reveals important differences in the sources and transport...
Authors
R. B. Alexander, R. A. Smith, G. E. Schwarz, E.W. Boyer, J.V. Nolan, J. W. Brakebill
Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003 Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003
This study focused on three areas that might be of interest to water-quality managers in the Pacific Northwest: (1) annual loads of total nitrogen (TN), total phosphorus (TP) and suspended sediment (SS) transported through the Columbia River and Puget Sound Basins, (2) annual yields of TN, TP, and SS relative to differences in landscape and climatic conditions between subbasin catchments...
Authors
Daniel R. Wise, Frank A. Rinella, Joseph F. Rinella, Greg J. Fuhrer, Sandra S. Embrey, Gregory M. Clark, Gregory E. Schwarz, Steven Sobieszczyk
The role of headwater streams in downstream water quality The role of headwater streams in downstream water quality
Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality...
Authors
R. B. Alexander, E.W. Boyer, R. A. Smith, G. E. Schwarz, R. B. Moore
Changes in streamflow and water quality in selected nontidal basins in the Chesapeake Bay Watershed, 1985-2004 Changes in streamflow and water quality in selected nontidal basins in the Chesapeake Bay Watershed, 1985-2004
As part of an annual evaluation of water-quality conditions by the Chesapeake Bay Program, water-quality and streamflow data from 32 sites in nontidal parts of the Chesapeake Bay watershed were analyzed to document annual nutrient and sediment trends for 1985 through 2004. This study also formalized different trend tests and methodologies used in assessing the effectiveness of man...
Authors
Michael J. Langland, Jeff P. Raffensperger, Douglas Moyer, Jurate M. Landwehr, Gregory E. Schwarz
Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation Section 3. The SPARROW Surface Water-Quality Model—Theory, application and user documentation
SPARROW (SPAtially Referenced Regressions On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds containing the stations. The core of the model consists of a nonlinear regression equation describing the non-conservative transport of contaminants from point and diffuse...
Authors
Gregory Schwarz, Anne B. Hoos, R. B. Alexander, R. A. Smith