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The collection of borehole geophysical logs and images and continuous water-level data was conducted by the U.S. Geological Survey South Atlantic Water Science Center in the vicinity of the GMH Electronics Superfund site near Roxboro, North Carolina, during December 2012 through July 2015. The study purpose was part of a continued effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants. Previous work by the U.S. Geological Survey South Atlantic Water Science Center at the site involved similar data collection, in addition to surface geologic mapping and passive diffusion...
Categories: Data;
Types: Citation;
Tags: North Carolina,
Person County,
Roxboro,
fractured-rock aquifer,
geophysical logging,
This dataset includes the magnetotelluric (MT) sounding data collected in 2009 in and near the San Luis Basin, New Mexico. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Basin to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Basin region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management...
These data contain concentrations of tetrachloroethylene in shallow groundwater samples collected in 2015 by the U.S. Environmental Protection Agency (EPA). These data are a subset of all the groundwater at the site. Samples were collected using direct-push technology. Only samples collected within the study area on 1 of the 10 sampling periods discussed in the journal article are included in this data set. In order to protect personally identifiable information (PII), all data collected by the U.S. Environmental Protection Agency do not contain spatial information. Please contact the U.S. Environmental Protection Agency for permission and access to spatial information for these samples. These data support...
Water quality and optical absorbance data for journal article entitled, "The removal kinetics of dissolved organic matter and the optical clarity of groundwater" by Francis H. Chapelle, Yuan Shen, Eric W. Strom, and Ronald Benner. Hydrogeology Journal. In Press.
A two-dimensional finite element model was used to simulate the groundwater recovery process under various surface mining situations. The simulation results were used to predict the rate at which soil settlement takes place. It was found that the groundwater recovery process is very fast immediately after mine closure and cessation of dewatering programmes; a significant part of mine land settlement can be measured at such times. This paper presents a method for deriving the relationship between the re-establishment of the natural groundwater regime to its equilibrium position as existed prior to the commencement of mining operations and mine spoil settlement.
Categories: Publication;
Types: Citation;
Tags: Modelling,
groundwater,
land settlement,
prediction,
recovery process,
Summary A detailed local-scale monitoring network was used to assess CFC distribution in an unconfined sand aquifer in southwestern Ontario where the zone of 1–5-year-old groundwater was known with certainty because of prior use of a bromide tracer. Groundwater ⩽5 years old was confined to an aerobic zone at ⩽5 m depth and had CFC concentrations consistent with modern atmospheric mixing ratios at recharge temperatures of 7–11 °C, as was observed in the 3-m thick vadose zone at the site. At depths below 6 m, the groundwater became progressively more reducing, however, with a denitrifying horizon at 6–7 m depth, and a Mn and Fe reducing zone below 7 m depth. In the anaerobic zone, 3H/3He ratios indicated that groundwater-age...
We examined the chemical reactions influencing dissolved concentrations, speciation, and transport of naturally occurring arsenic (As) in a shallow, sand and gravel aquifer with distinct geochemical zones resulting from land disposal of dilute sewage effluent. The principal geochemical zones were: (1) the uncontaminated zone above the sewage plume [350 µM dissolved oxygen (DO), pH 5.9]; (2) the suboxic zone (5 µM DO, pH 6.2, elevated concentrations of sewage-derived phosphate and nitrate); and (3) the anoxic zone [dissolved iron(II) 100–300 µM, pH 6.5–6.9, elevated concentrations of sewage-derived phosphate]. Sediments are comprised of greater than 90% quartz but the surfaces of quartz and other mineral grains are...
Categories: Publication;
Types: Citation;
Tags: Arsenic,
Contamination,
Geochemistry,
Groundwater,
qua
This study proposes the use of several problems of unstable steady state convection with variable fluid density in a porous layer of infinite horizontal extent as two-dimensional (2-D) test cases for density-dependent groundwater flow and solute transport simulators. Unlike existing density-dependent model benchmarks, these problems have well-defined stability criteria that are determined analytically. These analytical stability indicators can be compared with numerical model results to test the ability of a code to accurately simulate buoyancy driven flow and diffusion. The basic analytical solution is for a horizontally infinite fluid-filled porous layer in which fluid density decreases with depth. The proposed...
Categories: Publication;
Types: Citation;
Tags: Benchmark,
Convection,
Groundwater,
Modelling,
Variable-density,
Groundwater is a key driver of riparian condition on dryland rivers but is in high demand for municipal, industrial, and agricultural uses. Approaches are needed to guide decisions that balance human water needs while conserving riparian ecosystems. We developed a space-for-time substitution model that links groundwater change scenarios implemented within a Decision Support System (DSS) with proportions of floodplain vegetation types and abundances of breeding and migratory birds along the upper San Pedro River, AZ, USA. We investigated nine scenarios ranging from groundwater depletion to recharge. In groundwater decline scenarios, relative proportions of tall-canopied obligate phreatophytes (Populus/Salix, cottonwood/willow)...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Ecohydrology,
Populus,
Tamarix,
avian abundance,
dryland river,
The dataset is a model archive containing all relevant files to document and re-run the models that are discussed in the report: Fenelon, J.M., Halford, K.J., and Moreo, M.T., 2016, Delineation of the Pahute Mesa-Oasis Valley groundwater basin, Nevada: U.S. Geological Survey Scientific Investigations Report 2015-5175, http://dx.doi.org/10.3133/sir20155175.
Types: Citation;
Tags: Hydrogeology,
Nye County,
Oasis Valley,
Pahute Mesa,
USGS Science Data Catalog (SDC),
The West Hills of Portland, in the southern Tualatin Mountains, trend northwest along the west side of Portland, Oregon. These silt-mantled mountains receive significant wet-season precipitation and are prone to sliding during wet conditions, occasionally resulting in significant property damage or casualties. In an effort to develop a baseline for interpretive analysis of the groundwater response to rainfall, an automated monitoring system was installed in 2006 to measure rainfall, pore-water pressure, soil suction, soil-water potential, and volumetric water content at 15-minute intervals. The data show a cyclical pattern of groundwater and moisture content levels—wet from October to May and dry between June and...
Categories: Data;
Types: Citation;
Tags: GHSC,
Geologic Hazards Science Center,
Hydrogeology,
LHP,
Landslide Hazards Program,
The Conservation Reserve Program (CRP) is one of the largest programs of the U.S. Department of Agriculture (USDA) that encourages farmers and ranchers to establish resource-conserving vegetative covers to address soil, water and related resource issues on their lands. This research study examines the relationship between the CRP and the changes in the groundwater levels within Texas County in the Oklahoma Panhandle region. The region overlies the central portion of the High Plains Aquifer that has shown significant decline in groundwater levels, due largely to the development of irrigated agriculture. Using the calibrated SWAT (Soil and Water Assessment Tool) model and GIS-based analysis, a significant spatial...
Categories: Publication;
Types: Citation;
Tags: Conservation reserve program,
Data Visualization & Tools,
GIS,
Groundwater,
Landscapes,
Natural landscapes in the Southwestern United States are changing. In recent decades, rising temperatures and drought have led to drier conditions, contributed to large-scale ecological impacts, and affected many plant and animal species across the region. The current and future trajectory of climate change underscores the need for managers and conservation professionals to understand the impacts of these patterns on natural resources. In this regional assessment of the Southwest Climate Change Initiative, we evaluate changes in annual average temperatures from 1951–2006 across major habitats and large watersheds and compare these changes to the number of species of conservation concern that are found within these...
Categories: Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Chihuahuan Desert,
English,
Madrean,
Mojave Desert,
Sonoran Desert,
Final Report - Executive Summary: This final project report is prepared to summarize the research project titled “Assessing evapotranspiration rate changes for proposed restoration of the forested uplands of the Desert Landscape Conservation Cooperatives (LCC)” for the Desert LCC of the Bureau of Reclamation as a requirement for closing out the project. This report includes the scope of work, summary of research project, results, and conclusions.Among all of the components of the terrestrial water cycle, evapotranspiration (ET) consumes the largest amount of water. Accurate estimation of ET is very important to understand the influence of ET to the hydrologic response of recharge and runoff processes in the water...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2012,
ATMOSPHERE,
ATMOSPHERE,
ATMOSPHERIC WATER VAPOR,
ATMOSPHERIC WATER VAPOR,
Groundwater-quality data collected between 1993 and 2015 were compiled from the U.S. Geological Survey (USGS) National Water Information System (NWIS) database for 722 wells in the San Joaquin Valley (SJV). Groundwater-quality data retrieved included lab analyses of complete major ion data (calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate, alkalinity, bicarbonate, carbonate, silica, and TDS) for 613 samples, and an additional 109 samples with measured values of specific conductance. Most of these wells were sampled as part of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project or the USGS National Water Quality Assessment (NAWQA) Program. In addition...
Categories: Data;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Agriculture,
California,
Central Valley,
Environment,
GAMA,
Flow regulation has reduced the exchange of water, energy, and materials between rivers and floodplains, caused declines in native plant populations, and advanced the spread of nonnative plants. Naturalized flow regimes are regarded as a means to restore degraded riparian areas. We examined the effects of flood regime (short [SIFI] vs. long [LIFI] inter-flood interval) on plant community and soil inorganic nitrogen (N) dynamics in riparian forests dominated by native Populus deltoides var. wislizenii Eckenwalder (Rio Grande cottonwood) and nonnative Tamarix chinensis Lour. (salt cedar) along the regulated middle Rio Grande of New Mexico. The frequency of inundation (every 2–3 years) at SIFI sites better reflected...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Ecological Applications,
Ecological Society of America,
New Mexico (USA),
Populus deltoides,
Rio Grande cottonwood,
The process whereby hydrogeologists interpret the available information to produce a justifiable set of simplifying assumptions to describe a groundwater system is called conceptual modelling. Although this process is inherent in all hydrogeological assessments and can therefore be regarded as synonymous with hydrogeological practice there are no standard specifications for it. A framework for conceptual modelling has been designed to both assist in the planning and process of the work and to provide an audit trail to facilitate independent scrutiny. The application of this framework is illustrated by two case histories, one of a small-scale investigation for a proposed cemetery and the other of an investigation...
Categories: Publication;
Types: Citation;
Tags: Groundwater,
conceptual model,
environmental assessment,
hydrogeology,
impact assessment,
Raster showing change in water-table altitude between Fall of 2002 and Fall of 2015 in the alluvium in the Lower Arkansas River Valley, Southeast Colorado. Hereafter "fall" is defined as June 1 to November 30. All interpolation and geoprocessing was done using ArcGIS Desktop v10 (Environmental Systems Research Institute, 2011).
Categories: Data;
Types: Citation,
Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Arkansas River,
Bent County,
Crowley County,
Otero County,
Prowers County,
This dataset includes the magnetotelluric (MT) sounding data collected in 2009 in and near the San Luis Basin, New Mexico. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Basin to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Basin region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management...
This dataset includes the magnetotelluric (MT) sounding data collected in 2009 in and near the San Luis Basin, New Mexico. The U.S. Geological Survey conducted a series of multidisciplinary studies, including MT surveys, in the San Luis Basin to improve understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits comprising the principal groundwater aquifers of the Rio Grande rift. The shallow unconfined and the deeper confined Santa Fe Group aquifers in the San Luis Basin are the main sources of municipal water for the region. The population of the San Luis Basin region is growing rapidly and water shortfalls could have serious consequences. Future growth and land management...
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