In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project of the National Water-Quality Program. One of the major goals of the NAWQA project is to determine how water-quality and ecological conditions change over time. To support that goal, long-term consistent and comparable ecological monitoring has been conducted on streams and rivers throughout the Nation. Fish, invertebrate, and algae data collected as part of the NAWQA program were retrieved from the USGS Aquatic Bioassessment database for use in trend analysis. Ultimately, these data will provide insight into how natural features and human activities have contributed to changes in ecological condition over time in the Nations streams and rivers. This USGS data release contains all of the input and output files necessary to reproduce the results of the ecological trend analysis described in the associated U.S. Geological Survey Scientific Investigations Report (http://dx.doi.org/10.3133/sir20175006). Data preparation for input to the model is also fully described in the above mentioned report.
|Title||Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992-2012|
|Authors||Robert E. Zuellig, Melissa L. Riskin|
|Product Type||Data Release|
|Record Source||USGS Digital Object Identifier Catalog|
|USGS Organization||Office of Planning and Programming|
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 resultsSince 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 Water-QualAuthorsGretchen 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