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At least 1,297 records · Page 72Linked to original sources

Borehole Geophysical Logging Program: Incorporating New and Existing Techniques in Hydrologic Studies

The borehole geophysical logging program at the U.S. Geological Survey (USGS)-Florida Integrated Science Center (FISC) provides subsurface information needed to resolve geologic, hydrologic, and environmental issues in Florida. The program includes the acquisition, processing, display, interpretation, and archiving of borehole geophysical logs. The borehole geophysical logging program is a critical component of many FISC investigations, including hydrogeologic framework studies, aquifer flow-zone characterization, and freshwater-saltwater interface delineation.

Fact Sheet↗

USGS Toxic Substances Hydrology Program, 2010

The U.S. Geological Survey (USGS) Toxic Substances Hydrology Program adapts research priorities to address the most important contamination issues facing the Nation and to identify new threats to environmental health. The Program investigates two major types of contamination problems: * Subsurface Point-Source Contamination, and * Watershed and Regional Contamination. Research objectives include developing remediation methods that use natural processes, characterizing and remediating contaminant plumes in fractured-rock aquifers, identifying new environmental contaminants, characterizing new and understudied pesticides in common pesticide-use settings, explaining mercury methylation and bioaccumulation, and developing approaches for remediating watersheds affected by active and historic mining.

Fact Sheet↗

Hydrology of Johnson Creek Basin, a Mixed-Use Drainage Basin in the Portland, Oregon, Metropolitan Area

Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the Portland, Oregon, metropolitan area and through rural and agricultural land in unincorporated Multnomah and Clackamas Counties. Johnson Creek has had a history of persistent flooding and water-quality problems. The U.S. Geological Survey (USGS) has conducted streamflow monitoring and other hydrologic studies in the basin since 1941.

Fact Sheet↗

Using models for the optimization of hydrologic monitoring

Hydrologists are often asked what kind of monitoring network can most effectively support science-based water-resources management decisions. Currently (2011), hydrologic monitoring locations often are selected by addressing observation gaps in the existing network or non-science issues such as site access. A model might then be calibrated to available data and applied to a prediction of interest (regardless of how well-suited that model is for the prediction). However, modeling tools are available that can inform which locations and types of data provide the most 'bang for the buck' for a specified prediction. Put another way, the hydrologist can determine which observation data most reduce the model uncertainty around a specified prediction. An advantage of such an approach is the maximization of limited monitoring resources because it focuses on the difference in prediction uncertainty with or without additional collection of field data. Data worth can be calculated either through the addition of new data or subtraction of existing information by reducing monitoring efforts (Beven, 1993). The latter generally is not widely requested as there is explicit recognition that the worth calculated is fundamentally dependent on the prediction specified. If a water manager needs a new prediction, the benefits of reducing the scope of a monitoring effort, based on an old prediction, may be erased by the loss of information important for the new prediction. This fact sheet focuses on the worth or value of new data collection by quantifying the reduction in prediction uncertainty achieved be adding a monitoring observation. This calculation of worth can be performed for multiple potential locations (and types) of observations, which then can be ranked for their effectiveness for reducing uncertainty around the specified prediction. This is implemented using a Bayesian approach with the PREDUNC utility in the parameter estimation software suite PEST (Doherty, 2010). The techniques briefly described earlier are described in detail in a U.S. Geological Survey Scientific Investigations Report available on the Internet (Fienen and others, 2010; http://pubs.usgs.gov/sir/2010/5159/). This fact sheet presents a synopsis of the techniques as applied to a synthetic model based on a model constructed using properties from the Lake Michigan Basin (Hoard, 2010).

Fact Sheet↗

Effects of projected climate (2011–50) on karst hydrology and species vulnerability—Edwards aquifer, south-central Texas, and Madison aquifer, western South Dakota

Karst aquifers—formed by the dissolution of soluble rocks such as limestone—are critical groundwater resources in North America, and karst springs, caves, and streams provide habitat for unique flora and fauna. Springflow and groundwater levels in karst terrane can change greatly over short time scales, and therefore are likely to respond rapidly to climate change. How might the biological communities and ecosystems associated with karst respond to climate change and accompanying changes in groundwater levels and springflow? Sites in two central U.S. regions—the Balcones Escarpment of south-central Texas and the Black Hills of western South Dakota (fig. 1)—were selected to study climate change and its potential effects on the local karst hydrology and ecosystem. The ecosystems associated with the Edwards aquifer (Balcones Escarpment region) and Madison aquifer (Black Hills region) support federally listed endangered and threatened species and numerous State-listed species of concern, including amphibians, birds, insects, and plants. Full results are provided in Stamm and others (2014), and are summarized in this fact sheet.

South Dakota, Texas↗

Hydrologic enforcement of lidar DEMs

Hydrologic-enforcement (hydro-enforcement) of light detection and ranging (lidar)-derived digital elevation models (DEMs) modifies the elevations of artificial impediments (such as road fills or railroad grades) to simulate how man-made drainage structures such as culverts or bridges allow continuous downslope flow. Lidar-derived DEMs contain an extremely high level of topographic detail; thus, hydro-enforced lidar-derived DEMs are essential to the U.S. Geological Survey (USGS) for complex modeling of riverine flow. The USGS Coastal and Marine Geology Program (CMGP) is integrating hydro-enforced lidar-derived DEMs (land elevation) and lidar-derived bathymetry (water depth) to enhance storm surge modeling in vulnerable coastal zones.

Fact Sheet↗

Strategic needs of water on the Yukon: An interdisciplinary approach to studying hydrology and climate change in the Lower Yukon River Basin

Strategic Needs of Water on the Yukon (SNOWY) is an interdisciplinary research project funded by the National Science Foundation (NSF; http://www.nsf.gov/ ). The SNOWY team is made up of a diverse group of researchers from different backgrounds and organizations. This partnership between scientists from different disciplines (hydrology, geography, and social science), government agencies, nonprofit organizations, universities, and Lower Yukon River Basin (LYRB) and Yukon-Kuskokwim (YK) Delta communities provided an opportunity to study the effects of climate change using a holistic approach. The Arctic and Subarctic are experiencing environmental change at a rate faster than the rest of the world, and the lack of historical baseline data in these often remote locations makes understanding and predicting regional climate change difficult. This project focused on collecting data to fill in these gaps by using both quantitative and qualitative methodologies to tell the story of environmental change in this region as told by the physical data and the people who rely on this landscape.

Alaska↗

Transportation and Hydrology Studies of the U.S. Geological Survey in New England

The U.S. Geological Survey (USGS) has a long history of working with the Federal Highway Administration (FHWA) and State transportation agencies to provide data and information to address various issues related to water resources and the Nation’s transportation infrastructure. These issues include the following: • Streamgaging data networks • Flow frequencies and flow statistics • Water-quality investigations • Bridge scour and sediment transport • Hydrologic and hydraulic flood modeling In New England, the USGS is conducting investigations to improve flood flow estimation techniques, to define channel characteristics at bankfull discharge, and to document storm tide as a result of major coastal storms. Current locally focused investigations include examination of flow frequency in rural, urban, and small watersheds; documentation of extreme inland floods along with flood-frequency updates; examination of the effects of roadway blasting on groundwater quality; and determinations of the effects of road salting on the quality of runoff and receiving waters.

New England↗

Urban hydrology—Science capabilities of the U.S. Geological Survey

Urbanization affects streamflow characteristics, coastal flooding, and groundwater recharge. Increasing impervious areas, streamflow diversions, and groundwater pumpage are some of the ways that the natural water cycle is affected by urbanization. Assessment of the relations among these factors and changes in land use helps water-resource managers with issues such as stormwater management and vulnerability to flood and drought. Scientists with the U.S. Geological Survey (USGS) have the expertise to monitor and model urban hydrologic systems. Streamflow and groundwater data are available in national databases, and analyses of these data, including identification of long-term streamflow trends and the efficacy of management practices, are published in USGS reports.

Fact Sheet↗

Everglades Depth Estimation Network (EDEN)—A decade of serving hydrologic information to scientists and resource managers

Introduction The Everglades Depth Estimation Network (EDEN) provides scientists and resource managers with regional maps of daily water levels and depths in the freshwater part of the Greater Everglades landscape. The EDEN domain includes all or parts of five Water Conservation Areas, Big Cypress National Preserve, Pennsuco Wetlands, and Everglades National Park. Daily water-level maps are interpolated from water-level data at monitoring gages, and depth is estimated by using a digital elevation model of the land surface. Online datasets provide time series of daily water levels at gages and rainfall and evapotranspiration data ( https://sofia.usgs.gov/eden/ ). These datasets are used by scientists and resource managers to guide large-scale field operations, describe hydrologic changes, and support biological and ecological assessments that measure ecosystem response to the implementation of the Comprehensive Everglades Restoration Plan. EDEN water-level data have been used in a variety of biological and ecological studies including (1) the health of American alligators as a function of water depth, (2) the variability of post-fire landscape dynamics in relation to water depth, (3) the habitat quality for wading birds with dynamic habitat selection, and (4) an evaluation of the habitat of the Cape Sable seaside sparrow.

Florida↗

Hydrologic investigations of green infrastructure by the Central Midwest Water Science Center

The water management system within developed communities includes stormwater, wastewater, and drinking-water sources and sinks. Each water management system component provides critical services that support public health in these areas. Stormwater can be quite variable and difficult to manage in developed communities because the amount of stormwater that must be routed through a developed area depends on changing land cover and variable precipitation. In addition to flooding concerns, stormwater also is a major cause of water contamination in developed communities because it carries contaminants such as trash, bacteria, heavy metals, and sediments to local waterways. Historically, communities have managed stormwater with gray infrastructure such as street gutters, culverts, sewer systems, and tunnels. Although these structures efficiently capture and route stormwater to a local waterway or treatment plant, they do not filter any contaminants. Furthermore, many older communities have combined storm sewer and sanitary sewer systems. These combined systems result in an excessive amount of wastewater to be treated before being released into receiving water or the untreated waters are released directly to receiving waters during storms. Many communities are now incorporating green infrastructure stormwater mitigating solutions—pervious surfaces (allows water through), grassed swales, bioretention basins, and rain gardens—into their stormwater-management systems. Green infrastructure can absorb and filter stormwater where it falls by taking advantage of natural soil and plant storage and filtration capabilities. Thus, green infrastructure projects can potentially reduce the amount of stormwater and the concentration and transport of contaminants. Increasing green infrastructure in a developed community may reduce the requirements for new storm sewer infrastructure, improve the water quality of nearby waterways, and enhance aesthetics. The U.S. Geological Survey has partnered with several cooperators to quantify the effects of green infrastructure projects in several developed communities throughout the central Midwest. As part of these green infrastructure projects, the U.S. Geological Survey Central Midwest Water Science Center and cooperators installed, calibrated, and monitored equipment to measure hydrologic responses (including flooding and water movement) and selected water-quality constituents in developed communities.

Fact Sheet↗

Hydrologic technician postcard

Hydrologic technicians collect water data related to water quantity, quality, availability, and movement in surface-water and groundwater environments. For more information, visit https://www.usajobs.gov .

General Information Product↗

Digital data sets for map products produced as part of the Black Hills Hydrology Study, western South Dakota

This compact disk contains digital data produced as part of the 1:100,000-scale map products for the Black Hills Hydrology Study conducted in western South Dakota. The digital data include 28 individual Geographic Information System (GIS) data sets: data sets for the hydrogeologic unit map including all mapped hydrogeologic units within the study area (1 data set) and major geologic structure including anticlines and synclines (1 data set); data sets for potentiometric maps including the potentiometric contours for the Inyan Kara, Minnekahta, Minnelusa, Madison, and Deadwood aquifers (5 data sets), wells used as control points for each aquifer (5 data sets), and springs used as control points for the potentiometric contours (1 data set); and data sets for the structure-contour maps including the structure contours for the top of each formation that contains major aquifers (5 data sets), wells and tests holes used as control points for each formation (5 data sets), and surficial deposits (alluvium and terrace deposits) that directly overlie each of the major aquifer outcrops (5 data sets). These data sets were used to produce the maps published by the U.S. Geological Survey.

Open-File Report↗

Geologic, hydrologic, and water-quality data from multiple-well monitoring sites in the Central and West Coast basins, Los Angeles County, California, 1995-2000

In 1995, the U.S. Geological Survey (USGS), in cooperation with the Water Replenishment District of Southern California (WRDSC) , began a study to examine ground-water resources in the Central and West Coast Basins in Los Angeles County, California. The study characterizes the geohydrology and geochemistry of the regional ground-water flow system and provides extensive data for evaluating ground-water management issues. This report is a compilation of geologic, hydrologic, and water-quality data collected from 24 recently constructed multiple-well monitoring sites for the period 1995–2000. Descriptions of the collected drill cuttings were compiled into lithologic logs, which are summarized along with geophysical logs—including gamma-ray, spontaneous potential, resistivity, electromagnetic induction, and temperature tool logs—for each monitoring site. At selected sites, cores were analyzed for magnetic orientation, physical and thermal properties, and mineralogy. Field and laboratory estimates of hydraulic conductivity are presented for most multiple-well monitoring sites. Periodic water-level measurements are also reported. Water-quality information for major ions, nutrients, trace elements, deuterium and oxygen-18, and tritium is presented for the multiple-well monitoring locations, and for selected existing production and observation wells. In addition, boron-11, carbon-13, carbon-14, sulfur-34, and strontium-87/86 data are presented for selected wells.

Open-File Report↗

Geology, hydrology, and water quality in the vicinity of a brownfield redevelopment site in Canton, Illinois

The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency and Environmental Operations, Inc., assisted in the characterization of the geology, hydrology, and water quality at a Brownfield redevelopment site in Canton, Illinois. The investigation was designed to determine if metals and organic compounds historically used in industrial operations at the site resulted in a threat to the water resources in the area. The hydraulic units of concern in the study area are the upper semiconfining unit, the sand aquifer, and the lower semiconfining unit. The upper semiconfining unit ranges from about 1 to 19 feet in thickness and is composed of silt-and clay deposits with a geometric mean vertical hydraulic conductivity of 7.1 ? 10-3 feet per day. The sand aquifer is composed of a 1 to 5.5 foot thick sand deposit and is considered the primary pathway for ground-water flow and contaminant migration from beneath the study area. The geometric mean of the horizontal hydraulic conductivity of the sand aquifer was calculated to be 1.8 feet per day. The direction of flow in the sand aquifer is to the east, south, and west, away from a ground-water ridge that underlies the center of the site. Ground-water velocity through the sand aquifer ranges from 7.3 ? 10-2 to 2.7 ? 10-1 feet per day. The lower semiconfining unit is composed of sandy silt-and-clay deposits with a geometric mean vertical hydraulic conductivity of 1.1 ? 10-3 feet per day. Volatile organic compounds were detected in ground water beneath the study area. Pesticide compounds were detected in ground water in the western part of the study area. Partial or complete degradation of some of the volatile organic and pesticide compounds is occurring in the soils and ground water beneath the study area. Concentrations of most of the metals and major cations in the ground water show some variation within the study area and may be affected by the presence of a source area, pH, oxidation-reduction potential, precipitation-dissolution reactions, and ion exchange reactions. Antimony, thallium, and 1,1-dichloroethane were detected in water samples from one well each at concentrations above their respective U.S. Environmental Protection Agency maximum contaminant levels.

Open-File Report↗

Selected hydrologic data for Cedar Valley, Iron County, southwestern Utah, 1930-2001

This report presents hydrologic data collected by the U. S. Geological Survey from 1930 to 2001 with emphasis on data collected from 1997 to 2001 as part of a study of ground-water resources in Cedar Valley, Iron County, southwestern Utah (fig. 1). Data collected prior to this study are also presented to show long-term trends. Data were collected during this study in cooperation with the Central Iron County Water Conservancy District; Utah Department of Natural Resources, Division of Water Resources; Utah Department of Environmental Quality, Division of Water Quality; Cedar City; and Enoch City; as part of a study to better understand the ground-water resources of Cedar Valley and to assess possible effects of increased ground-water withdrawal on water quality. Quality of ground water in Cedar Valley is variable and water suppliers need to know if additional water resources can be developed without drawing water of lower quality into public-supply wells. Cedar Valley is in central Iron County at the transitional boundary between the Basin and Range and Colorado Plateau physiographic provinces described by Hunt (1974) and covers about 570 mi2. Additional data from wells west of Cedar Valley and to the south in the vicinity of Kanarraville in the Virgin River drainage (Colorado River Basin) adjacent to the study area are included. Cedar Valley is bounded on the east by the Markagunt Plateau and Red Hills, on the southwest by the Harmony Mountains, on the west by a complex of low hills, and on the north by the Black Mountains. Altitudes in the study area range from about 5,300 ft in Mud Spring Canyon to about 10,400 ft at Blowhard Mountain to the east.

Utah↗

Supporting data for hydrologic studies in San Francisco Bay, California: Meteorological measurements at the Port of Redwood City during 1998-2001

Meteorological data were collected during 1998-2001 at the Port of Redwood City, California, to support hydrologic studies in South San Francisco Bay. The measured meteorological variables were air temperature, atmospheric pressure, quantum flux (insolation), and four parameters of wind speed and direction: scalar mean horizontal wind speed, (vector) resultant horizontal wind speed, resultant wind direction, and standard deviation of the wind direction. Hourly mean values based on measurements at five-minute intervals were logged at the site. Daily mean values were computed for temperature, infolation, pressure, and scalar wind speed. Daily mean values for 1998-2001 are described in this report, and a short record of hourly mean values is compared to data from another near-by station. Data (hourly and daily mean) from the entire period of record (starting in April 1992) and reports describing data prior to 1998 are provided.

California↗

Hydrologic, water-quality, and sediment-quality data for the Christmas Bay system, Brazoria County, Texas, February 1999-March 2000

The Christmas Bay system is a group of three small secondary bays (Christmas, Bastrop, and Drum Bays) at the southwestern end of the Galveston Bay estuarine system in Brazoria County, Texas. During February 1999-March 2000, hydrologic, water-quality, and sediment-quality data were collected from each of the three bays to establish baseline conditions. Gage-height fluctuations closely matched open-water tidal fluctuations. Rainfall during February 1999-February 2000 was about 20 percent below the annual average. Specific conductance, pH, water temperature, and dissolved oxygen monitored at 30-minute intervals in Christmas Bay for 13 months showed seasonal variations typical of monitoring stations on the Texas Gulf Coast. Prevailing winds were from the southeast. Monthly water-quality sampling for 13 months showed that in each of the three bays concentrations of major ions were small, and most nutrient concentrations were at or less than minimum reporting levels; indicator bacteria counts were consistently higher in samples collected from Drum Bay. Several trace elements (sampled twice) were detected in small concentrations. The only organochlorine pesticides (sampled once) that were greater than minimum reporting levels were atrazine, deethylatrazine, metolachlor, and simazine. During February 29-March 29, 2000, three semipermeable membrane devices were deployed at the Christmas Bay monitoring station. Seven of 77 semivolatile organic compounds analyzed in the lipids from the devices were detected in minute amounts. Analyses of surficial bed sediment sampled once in each of the three bays yielded detections of a number of semivolatile organic compounds; all concentrations were less than 10 micrograms per liter and much less than the respective benchmark concentration for those compounds that have had a benchmark concentration established for the protection of aquatic life.

Texas↗