Lori Sprague (Former Employee)
Science and Products
Filter Total Items: 46
Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change
Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and...
Authors
Karen R. Ryberg, Joel D. Blomquist, Lori A. Sprague, Andrew J. Sekellick, Jennifer L. Keisman
Water-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results Water-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results
Since passage of the Clean Water Act in 1972, Federal, State, and local governments have invested billions of dollars to reduce pollution entering rivers and streams. To understand the return on these investments and to effectively manage and protect the Nation’s water resources in the future, we need to know how and why water quality has been changing over time. As part of the National...
Authors
Gretchen P. Oelsner, Lori A. Sprague, Jennifer C. Murphy, Robert E. Zuellig, Henry M. Johnson, Karen R. Ryberg, James A. Falcone, Edward G. Stets, Aldo V. Vecchia, Melissa L. Riskin, Laura A. De Cicco, Taylor J. Mills, William H. Farmer
Challenges with secondary use of multi-source water-quality data in the United States Challenges with secondary use of multi-source water-quality data in the United States
Combining water-quality data from multiple sources can help counterbalance diminishing resources for stream monitoring in the United States and lead to important regional and national insights that would not otherwise be possible. Individual monitoring organizations understand their own data very well, but issues can arise when their data are combined with data from other organizations...
Authors
Lori A. Sprague, Gretchen P. Oelsner, Denise M. Argue
Antecedent flow conditions and nitrate concentrations in the Mississippi River basin Antecedent flow conditions and nitrate concentrations in the Mississippi River basin
The relationship between antecedent flow conditions and nitrate concentrations was explored at eight sites in the 2.9 million square kilometers (km2) Mississippi River basin, USA. Antecedent flow conditions were quantified as the ratio between the mean daily flow of the previous year and the mean daily flow from the period of record (Qratio), and the Qratio was statistically related to...
Authors
Jennifer C. Murphy, Robert M. Hirsch, Lori A. Sprague
Nitrate in the Mississippi River and its tributaries, 1980-2010: an update Nitrate in the Mississippi River and its tributaries, 1980-2010: an update
Nitrate concentration and flux were estimated from 1980 through 2010 at eight sites in the Mississippi River Basin as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). These estimates extend the results from a previous investigation that provided nitrate estimates from 1980 through 2008 at the same sites. From 1980 through 2010, annual...
Authors
Jennifer C. Murphy, Robert M. Hirsch, Lori A. Sprague
Estimated anthropogenic nitrogen and phosphorus inputs to the land surface of the conterminous United States--1992, 1997, and 2002 Estimated anthropogenic nitrogen and phosphorus inputs to the land surface of the conterminous United States--1992, 1997, and 2002
Anthropogenic inputs of nitrogen and phosphorus to each county in the conterminous United States and to the watersheds of 495 surface-water sites studied as part of the U.S. Geological Survey National Water-Quality Assessment Program were quantified for the years 1992, 1997, and 2002. Estimates of inputs of nitrogen and phosphorus from biological fixation by crops (for nitrogen only)...
Authors
Lori A. Sprague, Jo Ann M. Gronberg
Science and Products
Filter Total Items: 46
Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change
Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and...
Authors
Karen R. Ryberg, Joel D. Blomquist, Lori A. Sprague, Andrew J. Sekellick, Jennifer L. Keisman
Water-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results Water-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results
Since passage of the Clean Water Act in 1972, Federal, State, and local governments have invested billions of dollars to reduce pollution entering rivers and streams. To understand the return on these investments and to effectively manage and protect the Nation’s water resources in the future, we need to know how and why water quality has been changing over time. As part of the National...
Authors
Gretchen P. Oelsner, Lori A. Sprague, Jennifer C. Murphy, Robert E. Zuellig, Henry M. Johnson, Karen R. Ryberg, James A. Falcone, Edward G. Stets, Aldo V. Vecchia, Melissa L. Riskin, Laura A. De Cicco, Taylor J. Mills, William H. Farmer
Challenges with secondary use of multi-source water-quality data in the United States Challenges with secondary use of multi-source water-quality data in the United States
Combining water-quality data from multiple sources can help counterbalance diminishing resources for stream monitoring in the United States and lead to important regional and national insights that would not otherwise be possible. Individual monitoring organizations understand their own data very well, but issues can arise when their data are combined with data from other organizations...
Authors
Lori A. Sprague, Gretchen P. Oelsner, Denise M. Argue
Antecedent flow conditions and nitrate concentrations in the Mississippi River basin Antecedent flow conditions and nitrate concentrations in the Mississippi River basin
The relationship between antecedent flow conditions and nitrate concentrations was explored at eight sites in the 2.9 million square kilometers (km2) Mississippi River basin, USA. Antecedent flow conditions were quantified as the ratio between the mean daily flow of the previous year and the mean daily flow from the period of record (Qratio), and the Qratio was statistically related to...
Authors
Jennifer C. Murphy, Robert M. Hirsch, Lori A. Sprague
Nitrate in the Mississippi River and its tributaries, 1980-2010: an update Nitrate in the Mississippi River and its tributaries, 1980-2010: an update
Nitrate concentration and flux were estimated from 1980 through 2010 at eight sites in the Mississippi River Basin as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). These estimates extend the results from a previous investigation that provided nitrate estimates from 1980 through 2008 at the same sites. From 1980 through 2010, annual...
Authors
Jennifer C. Murphy, Robert M. Hirsch, Lori A. Sprague
Estimated anthropogenic nitrogen and phosphorus inputs to the land surface of the conterminous United States--1992, 1997, and 2002 Estimated anthropogenic nitrogen and phosphorus inputs to the land surface of the conterminous United States--1992, 1997, and 2002
Anthropogenic inputs of nitrogen and phosphorus to each county in the conterminous United States and to the watersheds of 495 surface-water sites studied as part of the U.S. Geological Survey National Water-Quality Assessment Program were quantified for the years 1992, 1997, and 2002. Estimates of inputs of nitrogen and phosphorus from biological fixation by crops (for nitrogen only)...
Authors
Lori A. Sprague, Jo Ann M. Gronberg