Changes in anthropogenic influences on streams and rivers in the conterminous U.S. over the last 40 years, derived for 16 data themes

This product consists of time-series calculations of anthropogenic characteristics derived for 16 data themes for multiple scales covering the conterminous United States. The characteristics are those which (a) have consistent data sources, and (b) have the potential to affect the water quality of streams and rivers. All 16 data themes are provided for Hydrologic Unit Code level-10 (HUC-10) boundaries (n = 15,458). Additionally, measures of land use and imperviousness are provided for U.S. Environmental Protection Agency (USEPA) Level 4 ecoregions (n = 967) and for U.S. counties (n = 3,109). The data may be scaled up to broader areas; that is, HUC-10 data may be scaled up to HUC-8, 6, 4, or HUC-2 areas, Level 4 ecoregions may be scaled up to Levels 3, 2, and 1, and counties may be scaled up to States or multi-state regions. The 16 broad categories of data are: (1) atmospheric deposition (1985-2012), (2) agricultural production and livestock (1969-2012), (3) land in the Conservation Reserve Program (1986-2014), (4) dams and reservoirs (1972-2013), (5) housing unit density (1970-2010) and population density (1990-2010), (6) imperviousness (1974-2012 and 2001-2011), (7) irrigation (1969-2012 and 2002-2012), (8) land use (1974-2012 and 2001-2011), (9) land use in 200-meter flow distance riparian buffers (1974-2012), (10) nitrogen and phosphorus application from fertilizer (1987-2012), (11) nitrogen and phosphorus application from manure (1982-2012), (12) pesticide application (1992-2012), (13) road salt application (1992-2012), (14) timber and forest cutting (1999-2012), (15) freshwater withdrawal water use (1985-2010), and (16) wastewater treatment plant nitrogen and phosphorus yields (1978-2012). The temporal resolution of the source data vary by dataset, and range from annual to decadal data. The data posted here consist of tabular data and shapefiles to which the data may be joined.