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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 conditions change over time. To support that goal, long-term consistent and comparable monitoring has been conducted on streams and rivers throughout the Nation. Outside of the NAWQA project, the USGS also has collected long-term water-quality data to support additional assessments of changing water-quality conditions. These data have been combined to provide insight into how natural features and human activities have contributed...
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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 conditions change over time. To support that goal, long-term consistent and comparable monitoring has been conducted on streams and rivers throughout the Nation. Outside of the NAWQA project, the USGS and other Federal, State, and local agencies also have collected long-term water-quality data to support their own assessments of changing water-quality conditions. Data from these multiple sources have been combined to support...
Categories: Data;
Types: Citation;
Tags: Puerto Rico,
United States,
WRTDS,
carbon,
discharge, All tags...
nutrients,
rivers,
salinity,
sediment,
trends,
usgsnawqaswtrends,
weighted regression, Fewer tags
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This dataset consists of a series of rasters covering the conterminous United States. Each raster is a one kilometer (km) grid for 18 selected Census of Agriculture statistics mapped to land use pixels for the time period 1950 to 2012. A supplemental set of 9 statistics mapped at the entire county level are also provided as 1-km rasters. The rasters are posted as ArcGIS grids. The statistics represent values for crops, livestock, irrigation, fertilizer, and manure usage. Most statistics are mapped for all 14 Census of Agriculture reporting years in that time frame: 1950, 1954, 1959, 1964, 1969, 1974, 1978, 1982, 1987, 1992, 1997, 2002, 2007, and 2012.
Categories: Data;
Types: Citation;
Tags: Census of Agriculture,
Conterminous U.S.,
Cropland,
Crops,
Dasymetric mapping, All tags...
Fertilizer,
Historical agricultural data,
Irrigation,
Land Use Change,
Land use,
Livestock,
Manure,
NWALT,
National Water Quality Program,
USGS Science Data Catalog (SDC),
United States, Fewer tags
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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 conditions change over time. To support that goal, long-term consistent and comparable monitoring has been conducted on streams and rivers throughout the Nation. Outside of the NAWQA project, the USGS also has collected long-term water-quality data to support additional assessments of changing water-quality conditions. These data have been combined to provide insight into how natural features and human activities have contributed...
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Anthropogenic impervious surfaces affect hydrology, water quality, and ecological health and are widely studied. Previous studies have been limited, however, by a lack of consistent representation of imperviousness nationally as a time series prior to 2001. This product presents estimated imperviousness at 60-meter spatial resolution, for the time periods 1974, 1982, 1992, 2002, and 2012. The mapping was derived by comparing imperviousness from the National Land Cover Database (NLCD) 2011 to national land use from the 2012 U.S. Geological Survey NAWQA Wall-to-wall Anthropogenic Land Use Trends (NWALT) product. The NWALT land use product includes a series of 60-m national rasters, containing 18 land use classes,...
Types: Citation;
Tags: Coefficients of imperviousness,
Geography,
Imperviousness,
Land Use Change,
Land use, All tags...
Land use change,
National Water Quality Program,
USGS Science Data Catalog (SDC),
United States,
Water Resources, Fewer tags
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