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At least 1,369 records · Page 76Linked to original sources
USGS2014

Low-altitude photographic transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013

During July 16–18, 2013, low-level photography flights were conducted (with a Cessna 185 with floats and a Cessna 206 with tundra tires) over the five administrative units of the National Park Service Arctic Network (Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Gates of the Arctic National Park and Preserve, Kobuk Valley National Park, and Noatak National Preserve) and the U.S. Fish and Wildlife Service’s Selawik National Wildlife Refuge in northwest Alaska, to provide images of current conditions and prevalence of land-cover types as a baseline for measuring future change, and to complement the existing grid-based sample photography of the region. Total flight time was 17 hours, 46 minutes, and total flight distance was 2,590 kilometers, at a mean altitude of about 300 meters above ground level. A total of 19,167 photographs were taken from five digital camera systems: 1. A Drift® HD-170 (focal length 5.00 mm); 2. A GoPro® Hero3 Black Edition (focal length 2.77 mm); 3. A Panasonic® Lumix DMC-FZ200 (24× superzoom with variable focal length); 4. A Panasonic® Lumix DMC-SZ7 (10x superzoom with variable focal length); and 5. A Canon® Rebel 3Ti with a Sigma zoom lens (18–200 mm focal length). The Drift® HD-170 and GoPro® Hero3 cameras were secured to the struts and underwing for nadir (direct downward) imaging. The Panasonic® and Canon® cameras were each hand-held for oblique-angle landscape images, shooting through the airplanes’ windows, targeting both general landscape conditions as well as landscape features of special interest, such as tundra fire scars and landslips. The Drift® and GoPro® cameras each were set for time-lapse photography at 5-second intervals for overlapping coverage. Photographs from all cameras (100 percent .jpg format) were date- and time-synchronized to geographic positioning system waypoints taken during the flights, also at 5-second intervals, providing precise geotagging (latitude-longitude) of all files. All photographs were adjusted for color saturation and gamma, and nadir photographs were corrected for lens distortion for the Drift® and GoPro® cameras’ 170° wide-angle distortion. EXIF (exchangeable image file format) data on camera settings and geotagging were extracted into spreadsheet databases. An additional 1 hour, 20 minutes, and 43 seconds of high-resolution videos were recorded at 60 frames per second with the GoPro® camera along selected transect segments, and also were image-adjusted and corrected for lens distortion. Geotagged locations of 12,395 nadir photographs from the Drift® and GoPro® cameras were overlayed in a geographic information system (ArcMap 10.0) onto a map of 44 ecotypes (land- and water-cover types) of the Arctic Network study area. Presence and area of each ecotype occurring within a geographic information system window centered on the location of each photograph were recorded and included in the spreadsheet databases. All original and adjusted photographs, videos, geographic positioning system flight tracks, and photograph databases are available by contacting ascweb@usgs.gov.

Alaska↗
USGS2014

Discharge, water temperature, and selected meteorological data for Vancouver Lake, Vancouver, Washington, water years 2011-13

The U.S. Geological Survey partnered with the Vancouver Lake Watershed Partnership in a 2-year intensive study to quantify the movement of water and nutrients through Vancouver Lake in Vancouver, Washington. This report is intended to assist the Vancouver Lake Watershed Partnership in evaluating potential courses of action to mitigate seasonally driven blooms of harmful cyanobacteria and to improve overall water quality of the lake. This report contains stream discharge, lake water temperature, and selected meteorological data for water years 2011, 2012, and 2013 that were used to develop the water and nutrient budgets for the lake.

Washington↗
USGS2014

Geospatial database of estimates of groundwater discharge to streams in the Upper Colorado River Basin

The U.S. Geological Survey, as part of the Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) initiative, compiled published estimates of groundwater discharge to streams in the Upper Colorado River Basin as a geospatial database. For the purpose of this report, groundwater discharge to streams is the baseflow portion of streamflow that includes contributions of groundwater from various flow paths. Reported estimates of groundwater discharge were assigned as attributes to stream reaches derived from the high-resolution National Hydrography Dataset. A total of 235 estimates of groundwater discharge to streams were compiled and included in the dataset. Feature class attributes of the geospatial database include groundwater discharge (acre-feet per year), method of estimation, citation abbreviation, defined reach, and 8-digit hydrologic unit code(s). Baseflow index (BFI) estimates of groundwater discharge were calculated using an existing streamflow characteristics dataset and were included as an attribute in the geospatial database. A comparison of the BFI estimates to the compiled estimates of groundwater discharge found that the BFI estimates were greater than the reported groundwater discharge estimates.

Arizona, Colorado, New Mexico, Utah, Wyoming↗
USGS2014

Digital topographic data based on lidar survey of Mount Shasta Volcano, California, July-September 2010

The most voluminous of the Cascade volcanoes, northern California’s Mount Shasta, is a massive compound stratovolcano composed of at least four main edifices constructed over a period of at least 590,000 years. An ancestral Shasta volcano was destroyed by Earth’s largest known Quaternary subaerial debris avalanche, which filled Shasta Valley, northwest of the volcano. The Hotlum cone, forming the present summit, the Shastina lava dome complex, and the Black Butte lava dome on the southwest flank, were constructed during the early Holocene. As part of the American Recovery and Reinvestment Act (ARRA) of 2009, the U.S. Geological Survey was awarded funding for high-precision airborne lidar (light detection and ranging) data collection at several volcanoes in the Cascade Range. Data collection was arranged by the Oregon Lidar Consortium, administered by the Oregon Department of Geology and Mineral Industries (DOGAMI). The Oregon Lidar Consortium contracted with Watershed Sciences, Inc., to collect 1,220 square km of high-precision airborne lidar data. These data provide a digital map of the ground surface beneath forest cover with horizontal resolution of 1 m (average of 1.82 ground laser returns per square meter) and estimated vertical accuracy of ±4 centimeters (1 sigma), and horizontal accuracies of ±1.5 centimeters. These data will contribute to monitoring and description of natural hazards, the study of regional geology and volcanic landforms, and analysis of landscape modification during and after the next volcanic eruption at Mount Shasta. Survey Bounding Coordinates: West Bounding Coordinate: −122.438774 East Bounding Coordinate: −121.888382 North Bounding Coordinate: 41.564495 South Bounding Coordinate: 41.126339

California↗
USGS2014

Land-margin ecosystem hydrologic data for the coastal Everglades, Florida, water years 1996-2012

Mangrove forests and salt marshes dominate the landscape of the coastal Everglades (Odum and McIvor, 1990). However, the ecological effects from potential sea-level rise and increased water flows from planned freshwater Everglades restoration on these coastal systems are poorly understood. The National Park Service (NPS) proposed the South Florida Global Climate Change Project (SOFL-GCC) in 1990 to evaluate climate change and the effect from rising sea levels on the coastal Everglades, particularly at the marsh/mangrove interface or ecotone (Soukup and others, 1990). A primary objective of SOFL-GCC project was to monitor and synthesize the hydrodynamics of the coastal Everglades from the upstream freshwater marsh to the downstream estuary mangrove. Two related hypotheses were set forward (Nuttle and Cosby, 1993): 1. There exists hydrologic conditions (tide, local rainfall, and upstream water deliveries), which characterize the location of the marsh/mangrove ecotone along the marine and terrestrial hydrologic gradient; and 2. The marsh/mangrove ecotone is sensitive to fluctuations in sea level and freshwater inflow from inland areas. Hydrologic monitoring of the SOFL-GCC network began in 1995 after startup delays from Hurricane Andrew (August 1992) and organizational transfers from the NPS to the National Biological Survey (October 1993) and the merger with the U.S. Geological Survey (USGS) Biological Research Division in 1996 (Smith, 2004). As the SOFL-GCC project progressed, concern by environmental scientists and land managers over how the diversion of water from Everglades National Park would affect the restoration of the greater Everglades ecosystem. Everglades restoration scenarios were based on hydrodynamic models, none of which included the coastal zone (Fennema and others, 1994). Modeling efforts were expanded to include the Everglades coastal zone (Schaffranek and others, 2001) with SOFL-GCC hydrologic data assisting the ecological modeling needs. In 2002, as a response for a more interdisciplinary science approach to understanding the coastal Everglades ecological system, the SOFL-GCC hydrology project was integrated into the “Dynamics of Land-Margin Ecosystems: Historical Change, Hydrology, Vegetation, Sediment, and Climate” study (Smith and others, 2002). Data from the ongoing study has been useful in providing an empirical hydrologic baseline for the greater Everglades ecosystem restoration science and management needs. The hydrology network consisted of 13 hydrologic gaging stations installed in the southwestern coastal region of Everglades National Park along three transects: Shark River (Shark or SH) transect, Lostmans River (Lostmans or LO) transect, and Chatham River (Chatham or CH) transect (fig. 1). There were five paired surface-water/groundwater gaging stations on the Shark transect (SH1, SH2, SH3, SH4, and SH5) and one stage gaging station (BSC) in the Big Sable Creek; four paired surface-water/groundwater gaging stations on the Lostmans transect (LO1, LO2, LO3, and LO4); and three paired surface-water/groundwater gaging stations on the Chatham transect (CH1, CH2, and CH3). Both surface-water and groundwater levels, salinities, and temperatures were monitored at the paired gaging stations. Rainfall was recorded at marsh and open canopy gaging stations. This report details the study introduction, method, and description of data collected, which are accessible through the final instantaneous hydrologic dataset stored in the USGS South Florida Information Access (SOFIA) South Florida Hydrology Database website, http://sofia.usgs.gov/exchange/sfl_hydro_data/location.html#brdlandmargin .

Florida↗
USGS2014

A comprehensive list and photographic collection of the vascular flora of Caddo Lake National Wildlife Refuge, Texas, March 2011-March 2012

A floristics inventory was conducted to identify and photograph the vascular plants occurring at Caddo Lake National Wildlife Refuge (NWR), Texas, from March 2011 to March 2012 by the U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service. This research resulted in the identification of 511 taxa of vascular plants representing 111 families and 317 genera. Despite the degree of development of the refuge at the time it was transferred to the U.S. Fish and Wildlife Service, plant diversity was high. Of the 511 species identified in this study, 346 species are new records for Harrison County, and 3 species are new discoveries for Texas. Caddo Lake NWR is primarily forested with 55 tree species and 35 shrub species identified in this study. Of the species identified, 289 are associated with wetlands having a wetland classification of facultative or wetter, possibly reflecting the proximity of Caddo Lake to the refuge and the three streams that intersect the refuge. Sixty-two of the species found on the refuge are introduced. Chinese tallow tree ( Triadica sebifera ) is one of the more common invasive tree species on the refuge and is actively controlled by refuge staff. Chinese privet ( Ligustrum sinense ), sacred bamboo ( Nandina domestica ), and King’s Ranch bluestem ( Bothriochloa ischaemum var. songarica ) are present on the refuge and have the potential to become invasive. More than 10,000 photographs were taken of the plants found on the refuge in an effort to document general appearance and capture diagnostic characters of each plant species. Photographs were also taken of many of the animals and landscapes encountered during the project. Select images of each of the plants and animals are included in the collection of more than 1,600 photographs (all photographs by Larry Allain).

Texas↗
USGS2014

Mobile terrestrial light detection and ranging (T-LiDAR) survey of areas on Dauphin Island, Alabama, in the aftermath of Hurricane Isaac, 2012

Topographic survey data of areas on Dauphin Island on the Alabama coast were collected using a truck-mounted mobile terrestrial light detection and ranging system. This system is composed of a high frequency laser scanner in conjunction with an inertial measurement unit and a position and orientation computer to produce highly accurate topographic datasets. A global positioning system base station was set up on a nearby benchmark and logged vertical and horizontal position information during the survey for post-processing. Survey control points were also collected throughout the study area to determine residual errors. Data were collected 5 days after Hurricane Isaac made landfall in early September 2012 to document sediment deposits prior to clean-up efforts. Three data files in ASCII text format with the extension .xyz are included in this report, and each file is named according to both the acquisition date and the relative geographic location on Dauphin Island (for example, 20120903_Central.xyz). Metadata are also included for each of the files in both Extensible Markup Language with the extension .xml and ASCII text formats. These topographic data can be used to analyze the effects of storm surge on barrier island environments and also serve as a baseline dataset for future change detection analyses.

Alabama↗
USGS2014

Archive of digital chirp subbottom profile data collected during USGS cruise 12BIM03 offshore of the Chandeleur Islands, Louisiana, July 2012

From July 23 - 31, 2012, the U.S. Geological Survey conducted geophysical surveys to investigate the geologic controls on barrier island framework and long-term sediment transport along the oil spill mitigation sand berm constructed at the north end and just offshore of the Chandeleur Islands, La. (figure 1). This effort is part of a broader USGS study, which seeks to better understand barrier island evolution over medium time scales (months to years). This report serves as an archive of unprocessed digital chirp subbottom data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Gained (showing a relative increase in signal amplitude) digital images of the seismic profiles are also provided. Refer to the Abbreviations page for expansions of acronyms and abbreviations used in this report. The USGS St. Petersburg Coastal and Marine Science Center (SPCMSC) assigns a unique identifier to each cruise or field activity. For example, 12BIM03 tells us the data were collected in 2012 during the third field activity for that project in that calendar year and BIM is a generic code, which represents efforts related to Barrier Island Mapping. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity ID. All chirp systems use a signal of continuously varying frequency; the EdgeTech SB-424 system used during this survey produces high-resolution, shallow-penetration (typically less than 50 milliseconds (ms)) profile images of sub-seafloor stratigraphy. The towfish contains a transducer that transmits and receives acoustic energy and is typically towed 1 - 2 m below the sea surface. As transmitted acoustic energy intersects density boundaries, such as the seafloor or sub-surface sediment layers, energy is reflected back toward the transducer, received, and recorded by a PC-based seismic acquisition system. This process is repeated at regular time intervals (for example, 0.125 seconds (s)) and returned energy is recorded for a specific duration (for example, 50 ms). In this way, a two-dimensional (2-D) vertical image of the shallow geologic structure beneath the ship track is produced. Figure 2 displays the acquisition geometry. Refer to table 1 for a summary of acquisition parameters and table 2 for trackline statistics. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG Y rev. 0 format (Barry and others, 1975); the first 3,200 bytes of the card image header are in ASCII format instead of EBCDIC format. The SEG Y files may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU) (Cohen and Stockwell, 2010). See the How To Download SEG Y Data page for download instructions. The web version of this archive does not contain the SEG Y trace files. These files are very large and would require extremely long download times. To obtain the complete DVD archive, contact USGS Information Services at 1-888-ASK-USGS or infoservices@usgs.gov. The printable profiles provided here are GIF images that were processed and gained using SU software and can be viewed from the Profiles page or from links located on the trackline maps; refer to the Software page for links to example SU processing scripts. The SEG Y files are available on the DVD version of this report or on the Web, downloadable via the USGS Coastal and Marine Geoscience Data System (http://cmgds.marine.usgs.gov). The data are also available for viewing using GeoMapApp (http://www.geomapapp.org) and Virtual Ocean (http://www.virtualocean.org) multi-platform open source software. Detailed information about the navigation system used can be found in table 1 and the Field Activity Collection System (FACS) logs. To view the trackline maps and navigation files, and for more information about these items, see the Navigation page.

Louisiana↗
USGS2014

Baseline coastal oblique aerial photographs collected from Breton Island, Louisiana, to the Alabama-Florida border, July 13, 2013

The U.S. Geological Survey (USGS) conducts baseline and storm response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms. On July 13, 2013, the USGS conducted an oblique aerial photographic survey from Breton Island, Louisiana, to the Alabama-Florida border, aboard a Cessna 172 flying at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect baseline data for assessing incremental changes since the last survey, and the data can be used in the assessment of future coastal change. The images provided here are Joint Photographic Experts Group (JPEG) images. ExifTtool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. The photograph locations are an estimate of the position of the aircraft and do not indicate the location of any feature in the images (see the Navigation Data page). These photographs document the configuration of the barrier islands and other coastal features at the time of the survey. Pages containing thumbnail images of the photographs, referred to as contact sheets, were created in 5-minute segments of flight time. These segements can be found on the Photos and Maps page. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet. Table 1 provides detailed information about the GPS location, name, date, and time each of the 1242 photographs taken along with links to each photograph. The photography is organized into segments, also referred to as contact sheets, and represent approximately 5 minutes of flight time. (Also see the Photos and Maps page). In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML files were created using the photographic navigation files.

Alabama;Florida;Louisiana;Mississippi↗
USGS2014

Post-Hurricane Sandy coastal oblique aerial photographs collected from Cape Lookout, North Carolina, to Montauk, New York, November 4-6, 2012

The U.S. Geological Survey (USGS) conducts baseline and storm response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms. On November 4-6, 2012, approximately one week after the landfall of Hurricane Sandy, the USGS conducted an oblique aerial photographic survey from Cape Lookout, N.C., to Montauk, N.Y., aboard a Piper Navajo Chieftain (aircraft) at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect post-Hurricane Sandy data for assessing incremental changes in the beach and nearshore area since the last survey in 2009. The data can be used in the assessment of future coastal change. The photographs provided here are Joint Photographic Experts Group (JPEG) images. The photograph locations are an estimate of the position of the aircraft and do not indicate the location of the feature in the images. These photos document the configuration of the barrier islands and other coastal features at the time of the survey. Exiftool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet. Table 1 provides detailed information about the GPS location, image name, date, and time each of the 9,481 photographs were taken, along with links to each photograph. The photographs are organized in segments, also referred to as contact sheets, and represent approximately 5 minutes of flight time. In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML files were created using the photographic navigation files.

Delaware, Maryland, New Jersey, New York, North Ca↗
USGS2014

Baseline coastal oblique aerial photographs collected from Dauphin Island, Alabama, to Breton Island, Louisiana, August 8, 2012

The U.S. Geological Survey (USGS) conducts baseline and storm response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms. On August 8, 2012, the USGS conducted an oblique aerial photographic survey from Dauphin Island, Alabama, to Breton Island, Louisiana, aboard a Cessna 172 at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect baseline data for assessing incremental changes since the last survey, and the data can be used in the assessment of future coastal change. The images provided here are Joint Photographic Experts Group (JPEG) images. Exiftool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. The photograph locations are an estimate of the position of the aircraft and do not indicate the location of any feature in the images (see the Navigation Data page). These photographs document the configuration of the barrier islands and other coastal features at the time of the survey. Pages containing thumbnail images of the photographs, referred to as contact sheets, were created in 5-minute segments of flight time. These segements can be found on the Photos and Maps page. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet. Table 1 provides detailed information about the GPS location, name, date, and time each of the 1241 photographs taken along with links to each photograph. The photography is organized into segments, also referred to as contact sheets, and represent approximately 5 minutes of flight time. (Also see the Photos and Maps page). In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML files were created using the photographic navigation files.

Alabama;Louisiana↗
USGS2014

Baseline well inventory and groundwater-quality data from a potential shale gas resource area in parts of Lee and Chatham Counties, North Carolina, October 2011-August 2012

Records were obtained for 305 wells and 1 spring in northwestern Lee and southeastern Chatham counties, North Carolina. Well depths ranged from 26 to 720 feet and yields ranged from 0.25 to 100 gallons per minute. A subset of 56 wells and 1 spring were sampled for baseline groundwaterquality constituents including the following: major ions; dissolved metals; nutrients; dissolved gases (including methane); volatile and semivolatile organic compounds; glycols; isotopes of strontium, radium, methane (if sufficient concentration), and water; and dissolved organic and inorganic carbon. Dissolved methane gas concentrations were low, ranging from less than 0.00007 (lowest reporting level) to 0.48 milligrams per liter. Concentrations of nitrate, boron, iron, manganese, sulfate, chloride, total dissolved solids, and measurements of pH exceeded federal and state drinking water standards in a few samples. Iron and manganese concentrations exceeded the secondary (aesthetic) drinking water standard in approximately 35 to 37 percent of the samples.

North Carolina↗
USGS2014

USGS Arctic Ocean Carbon Cruise 2012: Field Activity L-01-12-AR to collect carbon data in the Arctic Ocean, August-September 2012

From August 25 to September 27, 2012, the United States Coast Guard Cutter (USCGC) Healy was part of an Extended Continental Shelf Project to determine the limits of the extended continental shelf in the Arctic. On a non-interference basis, a USGS ocean acidification team participated on the cruise to collect baseline water data in the Arctic. The collection of data extended from coastal waters near Barrow, Alaska, to 83°2'N., -175°36'W., and southward back to coastal waters near Barrow and on to Dutch Harbor, Alaska. As a consequence, a number of hypotheses were tested and questions asked associated with ocean acidification, including: What is the saturation state for different parts of the basin? What factors drive the saturation state in the different parts of the basin? How does saturation state compare to other regions? How do the carbon fluxes compare in the different parts of the basin? What is the buffering capacity of the water (Revelle factor)? What kind of variability does carbon demonstrate in the Arctic (near shore versus offshore and diurnal)? During the cruise, underway continuous and discrete water samples were collected, and discrete water samples were collected at stations to document the carbonate chemistry of the Arctic waters and quantify the saturation state of seawater with respect to calcium carbonate. These data are critical for providing baseline information in areas where no data have existed prior and will also be used to test existing models and predict future trends.

Arctic Ocean↗
USGS2014

Annual agricultural pesticide use for Midwest Stream-Quality Assessment, 2012-13

This report provides estimates of annual agricultural use of 190 pesticide compounds for counties and selected watersheds of Midwestern States for 2012 and 2013 compiled for subsequent analysis by the National Water-Quality Assessment Program, Midwest Stream-Quality Assessment (MSQA). One of the goals of MSQA is to characterize contaminants at perennial-stream sites throughout the Corn Belt. Evaluating pesticide inputs from agricultural sources will aid in that characterization. Crop acres for selected Midwestern crops were obtained from the Cropland Data Layer of the U.S. Department of Agriculture’s National Agricultural Statistics Service and used in conjunction with GfK Kynetec, Inc. proprietary Crop Reporting District-level pesticide-use data to estimate pesticide use for counties and watersheds. Estimated pesticide use (EPest) values were calculated by using both the “EPest-high” and “EPest-low” methods, the distinction being that there are more counties with estimated pesticide use for EPest-high compared to EPest-low, owing to differing assumptions about missing survey data. County-level and watershed-level estimates of annual agricultural pesticide use are provided as downloadable, tab-delimited files for both EPest-high and Epest-low. Summary graphs of MSQA watershed-level pesticide use for selected crops are also provided.

Data Series↗
USGS2014

Site-characteristic and hydrologic data for selected wells and springs on Federal land in Clark County, Nevada

Site-characteristic and hydrologic data for selected wells and springs on U.S. Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service, and U.S. Forest Service land in Clark County, Nevada, were updated in the U.S. Geological Survey’s National Water Information System (NWIS) to facilitate multi-agency research. Data were researched and reviewed, sites were visited, and NWIS data were updated for 231 wells and 198 springs, including 36 wells and 67 springs that were added to NWIS and 44 duplicate sites that were deleted. The site-characteristic and hydrologic data collected, reviewed, edited, and added to NWIS include locations, well water levels, spring discharges, and water chemistry. Site-characteristic and hydrologic data can be accessed from links to the NWIS web interface; data not available through the web interface are presented in appendixes to this report.

Nevada↗
USGS2014

Groundwater-quality data in the North San Francisco Bay Shallow Aquifer study unit, 2012: results from the California GAMA Program

Groundwater quality in the 1,850-square-mile North San Francisco Bay Shallow Aquifer (NSF-SA) study unit was investigated by the U.S. Geological Survey (USGS) from April to August 2012, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The NSF-SA study unit was the first study unit to be sampled as part of the second phase of the GAMA-PBP, which focuses on the shallow aquifer system. The GAMA NSF-SA study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the shallow aquifer systems and to facilitate statistically consistent comparisons of untreated-groundwater quality throughout California. The shallow aquifer system in the NSF-SA study unit was defined as the part of the aquifer system that is used by many private domestic wells and is shallower than the primary aquifer system used by many public-supply wells. In the NSF-SA study unit located in Marin, Mendocino, Napa, Solano, and Sonoma Counties, groundwater samples were collected from 71 wells. Seventy of the wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and one well was selected to aid in evaluation of water-quality issues (understanding well). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], pesticides, and pesticide degradates); constituents of special interest (perchlorate and 1,2,3-trichloropropane [1,2,3-TCP]); naturally occurring inorganic constituents (trace elements, nutrients, major and minor ions, silica, and total dissolved solids [TDS]); and radioactive constituents (radon-222 and gross alpha and gross beta radioactivity). Naturally occurring isotopes (stable isotopes of hydrogen, oxygen, boron, strontium, and inorganic carbon in water, tritium activities, and carbon-14 abundances) were measured to help identify the sources and ages of the sampled groundwater. In total, 207 constituents and water-quality indicators were measured. Three types of quality-control samples (blanks, replicates, and matrix spikes) were collected at up to 13 percent of the wells in the NSF-SA study unit, and the results for these samples were used to evaluate the quality of the data for the groundwater samples. Blanks rarely contained detectable concentrations of any constituent, suggesting that contamination from sample-collection procedures was not a significant source of bias in the data for the groundwater samples. Replicate samples generally were within the limits of acceptable analytical reproducibility. Matrix-spike recoveries were within the acceptable range (70 to 130 percent) for approximately 91 percent of the compounds. Most of the wells sampled for this study were private domestic wells. Private domestic wells are not regulated in California, and groundwater from these wells is rarely analyzed for water-quality constituents. Although regulatory benchmarks for drinking-water quality do not apply to private domestic wells, to provide some context for the results, concentrations of constituents measured in the untreated groundwater were compared with regulatory and non-regulatory health-based benchmarks established by the U.S. Environmental Protection Agency (USEPA) and California Department of Public Health (CDPH), to non-regulatory health-based benchmarks established by the USGS in cooperation with the USEPA, and to non-regulatory benchmarks established for aesthetic concerns by the CDPH. Comparisons between data collected for this study and benchmarks for drinking water are for illustrative purposes only and are not indicative of compliance or non-compliance with those benchmarks. Most of the organic and inorganic constituents that were detected in groundwater samples from the 70 grid wells in the NSF-SA study unit were detected at concentrations less than drinking-water benchmarks. Of the 149 organic and special-interest constituents analyzed for in groundwater samples, 31 were detected; concentrations of most detected constituents were less than regulatory and non-regulatory health-based benchmarks. One VOC, benzene, and one insecticide, dieldrin, were detected at concentrations above their respective health-based benchmarks. In total, VOCs were detected in 40 percent of the grid wells sampled, pesticides and pesticide degradates were detected in 13 percent, and perchlorate was detected in 27 percent of the 70 grid wells sampled. Groundwater samples from 70 grid wells were analyzed for trace elements, major and minor ions, nutrients, and radioactive constituents; most detected concentrations were less than health-based benchmarks. Exceptions are 12 detections of manganese greater than the USGS Health-Based Screening Level (HBSL), 7 detections of arsenic greater than the USEPA maximum contaminant level (MCL-US) of 10 micrograms per liter (μg/L), 2 detections of boron greater than the HBSL of 6,000 μg/L, 2 detections of fluoride greater than the CDPH maximum contaminant level (MCL-CA) of 2 milligrams per liter (mg/L), 2 detections of nitrate greater than the MCL-US of 10 mg/L, and two detections of radon-222 greater than the proposed MCL-US of 4,000 picocuries per liter. Results for constituents with non-regulatory benchmarks set for aesthetic concerns from the grid wells showed that iron concentrations greater than the CDPH secondary maximum contaminant level (SMCL-CA) of 300 μg/L were detected in 13 grid wells. Chloride was detected at a concentration greater than the SMCL-CA recommended benchmark of 250 mg/L in two grid wells. Sulfate concentrations greater than the SMCL-CA recommended benchmark of 250 mg/L were measured in two grid wells, and the concentration in one of these wells was also greater than the SMCL-CA upper benchmark of 500 mg/L. TDS concentrations greater than the SMCL-CA recommended benchmark of 500 mg/L were measured in 15 grid wells, and concentrations in 4 of these wells were also greater than the SMCL-CA upper benchmark of 1,000 mg/L.

California↗
USGS2014

Area- and depth- weighted averages of selected SSURGO variables for the conterminous United States and District of Columbia

This digital data release consists of seven data files of soil attributes for the United States and the District of Columbia. The files are derived from National Resources Conservations Service’s (NRCS) Soil Survey Geographic database (SSURGO). The data files can be linked to the raster datasets of soil mapping unit identifiers (MUKEY) available through the NRCS’s Gridded Soil Survey Geographic (gSSURGO) database ( http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/geo/?cid=nrcs142p2_053628 ). The associated files, named DRAINAGECLASS, HYDRATING, HYDGRP, HYDRICCONDITION, LAYER, TEXT, and WTDEP are area- and depth-weighted average values for selected soil characteristics from the SSURGO database for the conterminous United States and the District of Columbia. The SSURGO tables were acquired from the NRCS on March 5, 2014. The soil characteristics in the DRAINAGE table are drainage class (DRNCLASS), which identifies the natural drainage conditions of the soil and refers to the frequency and duration of wet periods. The soil characteristics in the HYDRATING table are hydric rating (HYDRATE), a yes/no field that indicates whether or not a map unit component is classified as a "hydric soil". The soil characteristics in the HYDGRP table are the percentages for each hydrologic group per MUKEY. The soil characteristics in the HYDRICCONDITION table are hydric condition (HYDCON), which describes the natural condition of the soil component. The soil characteristics in the LAYER table are available water capacity (AVG_AWC), bulk density (AVG_BD), saturated hydraulic conductivity (AVG_KSAT), vertical saturated hydraulic conductivity (AVG_KV), soil erodibility factor (AVG_KFACT), porosity (AVG_POR), field capacity (AVG_FC), the soil fraction passing a number 4 sieve (AVG_NO4), the soil fraction passing a number 10 sieve (AVG_NO10), the soil fraction passing a number 200 sieve (AVG_NO200), and organic matter (AVG_OM). The soil characteristics in the TEXT table are percent sand, silt, and clay (AVG_SAND, AVG_SILT, and AVG_CLAY). The soil characteristics in the WTDEP table are the annual minimum water table depth (WTDEP_MIN), available water storage in the 0-25 cm soil horizon (AWS025), the minimum water table depth for the months April, May and June (WTDEPAMJ), the available water storage in the first 25 centimeters of the soil horizon (AWS25), the dominant drainage class (DRCLSD), the wettest drainage class (DRCLSWET), and the hydric classification (HYDCLASS), which is an indication of the proportion of the map unit, expressed as a class, that is "hydric", based on the hydric classification of a given MUKEY. (See Entity_Description for more detail). The tables were created with a set of arc macro language (aml) and awk (awk was created at Bell Labsin the 1970s and its name is derived from the first letters of the last names of its authors – Alfred Aho, Peter Weinberger, and Brian Kernighan) scripts. Send an email to mewieczo@usgs.gov to obtain copies of the computer code (See Process_Description.) The methods used are outlined in NRCS's "SSURGO Data Packaging and Use" (NRCS, 2011). The tables can be related or joined to the gSSURGO rasters of MUKEYs by the item 'MUKEY.' Joining or relating the tables to a MUKEY grid allows the creation of grids of area- and depth-weighted soil characteristics. A 90-meter raster of MUKEYs is provided which can be used to produce rasters of soil attributes. More detailed resolution rasters are available through NRCS via the link above.

Data Series↗
USGS2014

Characterization of selected bed-sediment-bound organic and inorganic contaminants and toxicity, Barnegat Bay and major tributaries, New Jersey, 2012

A study of bed-sediment toxicity and organic and inorganic contaminants was conducted by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP). Bed-sediment samples were collected once from 22 sites in Barnegat Bay and selected major tributaries during August–September 2012 and analyzed for toxicity and a suite of organic and inorganic contaminants by the USGS and the U.S. Army Corps of Engineers. Sampling sites were selected to coincide with an existing water-quality monitoring network used by the NJDEP and others in order to evaluate water-quality conditions in Barnegat Bay and the surrounding watershed. Two of the 22 sites are reference sites and are within or adjacent to the study area; bed-sediment samples from reference sites allow for comparisons of results for the Barnegat Bay watershed to results from less affected settings within the region. Toxicity testing was conducted by exposing the estuarine amphipod Leptocheirus plumulosus and the freshwater amphipod Hyalella azteca to sediments for 28 days, and the percent survival, difference in biomass, and individual dry weights were measured. Reproductive effects also were evaluated for estuarine samples. Bed-sediment samples from four sites within Barnegat Bay were subjected to a toxicity identification evaluation to determine probable causes of toxicity. Samples were analyzed for a suite of 94 currently-used pesticides, 21 legacy pesticides, 24 trace elements, 40 polycyclic aromatic hydrocarbons, 7 polychlorinated biphenyls (PCBs) as Arochlor mixtures, and 145 individual PCB congeners. Concentrations of detected compounds were compared to sediment-quality guidelines, where appropriate.

New Jersey↗