Data

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 strongly controls

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 Screening Level (

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 at multipl

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 three h

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, Salmon, and Tr

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 suitable for

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 sensing da

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 often bette

The surface ecology of small ocean islands is directly linked to subsurface fresh water resources, which exist in the form of soil water and fresh groundwater lenses. The management of threaten plant species such as the tree Pisonia grandis needs to consider the spatial and temporal dynamics of groundwater lenses, particularly in a time of climate change. The Palmyra Atoll National Wildlife Refuge

The Neversink River watershed (above the Neversink Reservoir) has been a focus of U.S. Geological Survey (USGS) research regarding stream geochemistry, acidification, and ecology dynamics for decades. In 2019, the Water Mission Area Next Generation Water Observing Systems Program augmented the existing stream gage network there, including instrumentation to specifically characterize various aspect

In 2018, groundwater samples were collected from aquifers in the Williston Basin in parts of eastern Montana, western North Dakota, and northwestern South Dakota. This dataset includes quality-control data for volatile organic compounds that include data for source-solution blanks and field blanks. The dataset also includes data for sulfur hexafluoride in environmental samples of groundwater.

Residence time distribution (RTD) is a critically important characteristic of groundwater flow systems; however, it cannot be measured directly. RTD can be inferred from tracer data with analytical models (few parameters) or with numerical models (many parameters). The second approach permits more variation in system properties but is used less frequently than the first because large-scale numeric