Data

This data release contains low-streamflow trend results from 183 U.S. Geological Survey (USGS) streamgages and precipitation trend results from gaged watersheds within the Chesapeake Bay Watershed. Data include streamgage identification number, trend slopes and significance for several low-streamflow and precipitation metrics.

This data release contains annual peak-flow data through the 2013 water year, specification and output files from flood-frequency analysis of the annual peak-flow data in USGS PeakFQ software, a GIS shapefile of the basin polygons with attributes of site information, basin characteristics, results of flood-frequency analysis, and results of B-WLS/B-GLS analysis of skewness of the annual...

The mission of the U.S. Geological Survey (USGS) involves providing reliable, impartial, and timely information that is needed to understand the Nation?s water resource. New techniques that aid in achieving this mission are important, especially those that allow USGS to do so more accurately or cost-effectively. To this end, a new method for selecting the optimum exposure time for...

Water-quality data for groundwater samples collected from 4,824 sites between 1991 through 2018, and ancillary data and information on sampled wells and principal aquifers, were used to assess the occurrence and distribution of strontium in U.S. groundwater from 32 principal aquifers. This data release includes one tab-delimited text file detailing these data. Table: Chemical data from...

A boosted regression tree (BRT) model was developed to predict pH conditions in three-dimensions throughout the glacial aquifer system (GLAC) of the contiguous United States using pH measurements in samples from 18,258 wells and predictor variables that represent aspects of the hydrogeologic setting. Model results indicate that the carbonate content of soils and aquifer materials...

Lithium concentrations in untreated groundwater from 1,464 public-supply wells, 1,676 domestic-supply wells, and 1,560 monitoring wells distributed across 33 principal aquifers in the United States were evaluated for spatial variations and possible explanatory factors. For context, lithium concentrations are compared to a drinking-water only threshold (60 mg/L) and a Health-Based...

This dataset includes data collected to validate a method of analysis for arsenic species As(III), As(V), dimethylarsinate (DMA), and monomethylarsonate (MMA) in surface water and groundwater samples. It also includes site information and water chemistry for samples used in the validation and used for other studies of arsenic species in groundwater. It includes speciation data measured...

This groundwater-flow model archive contains heuristic model simulations evaluating the sustainability of groundwater withdrawals from public-water-supply wells on buried glacial aquifers. A total of 40 steady-state simulations and three transient simulations were run. The steady-state simulations were developed to assess the extent and connections between buried sand aquifers by varying...

The U.S. Geological Survey is monitoring concentrations of metals and other trace elements in water, streambed sediment, and aquatic invertebrates at 6 locations in the middle and lower portions of the mainstem Klamath River from below J.C. Boyle dam in Oregon to near the mouth on the northwestern coast of California. Included are 3 tributary monitoring sites, one each on the Scott...

This product provides tabular estimates of kilograms of nitrogen and phosphorus from a) fertilizer, and b) manure, for counties in the conterminous United States for the period 1950-2017. Data are generated for approximate five-year periods over the time, coinciding with U.S. Department of Agriculture Census of Agriculture census years. This data release also includes a model archive...

Remotely sensed imagery is increasingly used by emergency managers to monitor and map the impact of flood events to support preparedness, response, and critical decision making throughout the flood event lifecycle. To reduce latency in delivery of imagery-derived information, ensure consistent and reliably derived map products, and facilitate processing of an increasing volume of remote...

The distribution of permafrost in cold regions is subject to temporal and spatial changes influenced by climate, landscape disturbance, and ecosystem succession. Remote sensing from airborne and satellite platforms is increasing our understanding of landscape-scale permafrost distribution, but typically lacks the resolution to characterize finer-scale processes and phenomena, which are...