Data

This data set presents results from two groundwater tracing experiments conducted in the mudstone aquifer underlying the former Naval Air Warfare Center (NAWC), West Trenton, NJ. In each test, a bromide solution was introduced into a hydraulically isolated section of borehole 36BR (denoted as 36BR-A); the hydraulically isolated section of the borehole isolated specific bedding plane parting fractu

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 mapp

Household income is a potential predictor for a number of environmental influences, for example, application of urban pesticides. This product is a U.S. conterminous mapping of block group income derived from the 2010-2014 Census American Community Survey (ACS), adjusted by a 2013 county-level Cost-of-Living index obtained from the Council for Community and Economic Research. The resultant raster

This product is a 100-m raster which classifies urban lands in the conterminous United States by the year in which they were first developed. The classification is based on housing density by era for 1940-2010 developed by the University of Wisconsin-Madison SILVIS lab. The classification was applied by identifying a housing unit density threshold which matched current-era development as represe

A study of arroyo evolution in northern New Mexico (Friedman and others, 2015) assessed geomorphic change in the Chaco Wash arroyo from the 1930s to 2000. As part of this study, in October 2000 a trench was excavated across the arroyo bottom and a high-precision (Real-time kinematic) GPS survey was conducted. GPS survey data were used to georeference a 1930s topographic map and to identify key geo

There are two datasets in the compressed file along with individual metadata files which completely describe the datasets. The first data set consists of county estimates of nitrogen and phosphorus in kilograms from animal manure for the conterminous United States for 2007 and 2012. These data are available as both text files and spreadsheets. These estimates were based on county-level population

This dataset is comprised of water quality data and benthic macroinvertebrate data collected from basins in Colorado, USA, and Finland. The data includes ancillary water quality characteristics but also a suite of trace metals observed at each site. Also included are modeled outputs that characterize the bioavailability of each trace metal to a biotic ligand. These data were used to explore the im

The consequence of a 1996 wildfire disturbance and a subsequent high-intensity summer convective rain storm (~100 mm h-1) was the deposition of a sediment superslug in the Spring Creek basin (26.8 km2) of the Front Range Mountains in Colorado. Changes in the superslug near the confluence of Spring Creek with the South Platte River were monitored by cross-section surveys at 19 nearly equally-space

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 c

This dataset is a categorical mapping of estimated mean building heights, by Census block group, in shapefile format for the conterminous United States. The data were derived from the NASA Shuttle Radar Topography Mission, which collected first return (top of canopy and buildings) radar data at 30-m resolution in February, 2000 aboard the Space Shuttle Endeavor. These data were processed here to e

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 repre

Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2-yields and possible hydrogen isotopic fractionation. The elemental analyzerchromium/high temperature conversion react