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USGS2002

Geologic map of the Corona North 7.5' quadrangle, Riverside and San Bernardino Counties, California

Open-File Report 02-22 contains a digital geologic map database of the Corona North 7.5’ quadrangle, Riverside and San Bernardino Counties, California that includes: ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. A Postscript file to plot the geologic map on a topographic base, and containing a Correlation of Map Units diagram (CMU), a Description of Map Units (DMU), and an index map. Portable Document Format (.pdf) files of: a. This Readme; includes in Appendix I, data contained in crn_met.txt b. The same graphic as plotted in 2 above. Test plots have not produced precise 1:24,000- scale map sheets. Adobe Acrobat page size setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Geologic Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation name, age, and lithology. Where known, grain size is indicated on the map by a subscripted letter or letters following the unit symbols as follows: lg, large boulders; b, boulder; g, gravel; a, arenaceous; s, silt; c, clay; e.g. Qyfa is a predominantly young alluvial fan deposit that is arenaceous. Multiple letters are used for more specific identification or for mixed units, e.g., Qfysa is a silty sand. In some cases, mixed units are indicated by a compound symbol; e.g., Qyf2sc. Marine deposits are in part overlain by local, mostly alluvial fan, deposits and are labeled Qomf. Grain size follows f. Even though this is an Open-File Report and includes the standard USGS Open-File disclaimer, the report closely adheres to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the postscript file (2 above).

California↗

USGS2003

Preliminary geologic map of the Fontana 7.5' quadrangle, Riverside and San Bernardino Counties, California

Open-File Report 03-418 is a digital geologic data set that maps and describes the geology of the Fontana 7.5’ quadrangle, Riverside and San Bernardino Counties, California. The Fontana quadrangle database is one of several 7.5’ quadrangle databases that are being produced by the Southern California Areal Mapping Project (SCAMP). These maps and databases are, in turn, part of the nation-wide digital geologic map coverage being developed by the National Cooperative Geologic Map Program of the U.S. Geological Survey (USGS). General Open-File Report 03-418 contains a digital geologic map database of the Fontana 7.5’ quadrangle, Riverside and San Bernardino Counties, California that includes: 1. ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 7.2.1 coverages of the various elements of the geologic map. 2. A Postscript file (fon_map.ps) to plot the geologic map on a topographic base, and containing a Correlation of Map Units diagram (CMU), a Description of Map Units (DMU), and an index map. 3. An Encapsulated PostScript (EPS) file (fon_grey.eps) created in Adobe Illustrator 10.0 to plot the geologic map on a grey topographic base, and containing a Correlation of Map Units (CMU), a Description of Map Units (DMU), and an index map. 4. Portable Document Format (.pdf) files of: a. the Readme file; includes in Appendix I, data contained in fon_met.txt b. The same graphics as plotted in 2 and 3 above.Test plots have not produced precise 1:24,000-scale map sheets. Adobe Acrobat page size setting influences map scale. The Correlation of Map Units and Description of Map Units is in the editorial format of USGS Geologic Investigations Series (I-series) maps but has not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by standard geologic map criteria such as formation-name, age, and lithology. Where known, grain size is indicated on the map by a subscripted letter or letters following the unit symbols as follows: lg, large boulders; b, boulder; g, gravel; a, arenaceous; s, silt; c, clay; e.g. Qyfa is a predominantly young alluvial fan deposit that is arenaceous. Multiple letters are used for more specific identification or for mixed units, e.g., Qfysa is a silty sand. In some cases, mixed units are indicated by a compound symbol; e.g., Qyf2sc. Even though this is an Open-File Report and includes the standard USGS Open-File disclaimer, the report closely adheres to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (4b above) or plotting the postscript files (2 or 3 above).

California↗

USGS2001

Geologic map of the Chewelah 30' x 60' Quadrangle, Washington and Idaho

This data set maps and describes the geology of the Chewelah 30' X 60' quadrangle, Washington and Idaho. Created using Environmental Systems Research Institute's ARC/INFO software, the data base consists of the following items: (1) a map coverage containing geologic contacts and units, (2) a point coverage containing site-specific geologic structural data, (3) two coverages derived from 1:100,000 Digital Line Graphs (DLG); one of which represents topographic data, and the other, cultural data, (4) two line coverages that contain cross-section lines and unit-label leaders, respectively, and (5) attribute tables for geologic units (polygons), contacts (arcs), and site-specific data (points). In addition, the data set includes the following graphic and text products: (1) A PostScript graphic plot-file containing the geologic map, topography, cultural data, and two cross sections, and on a separate sheet, a Correlation of Map Units (CMU) diagram, an abbreviated Description of Map Units (DMU), modal diagrams for granitic rocks, an index map, a regional geologic and structure map, and a key for point and line symbols; (2) PDF files of the Readme text-file and expanded Description of Map Units (DMU), and (3) this metadata file. The geologic map database contains original U.S. Geological Survey data generated by detailed field observation and by interpretation of aerial photographs. The map was compiled from geologic maps of eight 1:48,000 15' quadrangle blocks, each of which was made by mosaicing and reducing the four constituent 7.5' quadrangles. These 15' quadrangle blocks were mapped chiefly at 1:24,000 scale, but the detail of the mapping was governed by the intention that it was to be compiled at 1:48,000 scale. The compilation at 1:100,000 scale entailed necessary simplification in some areas and combining of some geologic units. Overall, however, despite a greater than two times reduction in scale, most geologic detail found on the 1:48,000 maps is retained on the 1:100,000 map. Geologic contacts across boundaries of the eight constituent quadrangles required minor adjustments, but none significant at the final 1:100,000 scale. The geologic map was compiled on a base-stable cronoflex copy of the Chewelah 30' X 60' topographic base and then scribed. The scribe guide was used to make a 0.007 mil-thick blackline clear-film, which was scanned at 1200 DPI by Optronics Specialty Company, Northridge, California. This image was converted to vector and polygon GIS layers and minimally attributed by Optronics Specialty Company. Minor hand-digitized additions were made at the USGS. Lines, points, and polygons were subsequently edited at the USGS by using standard ARC/INFO commands. Digitizing and editing artifacts significant enough to display at a scale of 1:100,000 were corrected. Within the database, geologic contacts are represented as lines (arcs), geologic units as polygons, and site-specific data as points. Polygon, arc, and point attribute tables (.pat, .aat, and .pat, respectively) uniquely identify each geologic datum.

Miscellaneous Field Studies Map↗

USGS1995

Water-quality assessment of the Trinity River Basin, Texas— Analysis of available information on nutrients and suspended sediment, 1974-91

The U.S. Geological Survey is conducting an assessment of water quality in the Trinity River Basin as part of the National Water-Quality Assessment Program. During the planning phase of this study, existing information on nutrients and suspended sediment was compiled and analyzed. A total of about 5,700 water-quality samples were analyzed from local, State, and Federal agencies. Of these, about 4,200 were from streams and about 1,500 were from wells. Additionally, atmospheric deposition data for two locations were obtained and analyzed. Spatial variations in nutrient concentrations in streams are related primarily to point sources and reservoirs. Median total nitrogen concentrations downstream from major point sources, downstream from reservoirs, and on tributaries were 6.0, 1.3, and 2.4 milligrams per liter, respectively. Median total phosphorus concentrations for the same three settings were 1.6, O. 1, and 0.2 milligrams per liter, respectively. The largest concentrations occurred at low flow downstream from Dallas, Texas, when streamflow dominated by treated wastewater from point sources. The smallest concentrations occurred immediately downstream from reservoirs, which act as sinks for nutrients. Nutrient concentrations in agricultural areas were positively correlated to percent of drainage in agricultural land use and to discharge, indicating washoff of nutrients from nonpoint sources during storms. As with concentrations, nutrient loads were related to the presence of point sources and reservoirs. Loads increased substantially in the Dallas-Fort Worth area with the addition of nutrients from point sources; loads decreased substantially as flow passed through Livingston Reservoir. Concentrations of total nitrogen and total phosphorus did not change significantly, at the 95 percent confidence level, from 1974 to 1991 at most sites. The exception was a decrease in phosphorus concentrations at two sites downstream from major wastewater-treatment plants in the Dallas area. Concentrations of organic nitrogen and ammonia declined and concentrations of nitrite plus nitrate increased at sites below major wastewater-treatment plants. These changes are indicative of improvements in wastewater treatment that converts organic nitrogen and ammonia to nitrite and finally nitrate. Because nitrogen conversion reactions consume oxygen, the occurrence of these reactions at the treatment plants instead of in the streams resulted in reduced loading of biochemical oxygen demand to the streams. The only nutrient measured in ground water was nitrate. Nitrate concentrations varied by aquifer with the largest median concentrations in the Queen City and Nacatoch aquifers. There was a significant rank correlation between nitrate concentrations and depth of well for all seven aquifer groups sampled, with largest concentrations present in shallow wells. The large concentrations could result from nonpoint sources of nitrate associated with agricultural and urban land use; however, attempts to correlate nitrogen fertilizer application rates and agricultural land use to concentrations of nitrate in ground water were inconclusive. Only limited suspended-sediment data were available. Four sites had daily sediment-discharge records for three or more water years (October 1 to September 30) between 1974 and 1985. An additional three sites had periodic measurements of suspended-sediment concentrations. There are differences in concentrations and yields among sites; however, the limited amount of data precludes developing statistical or cause-and-effect relations with environmental factors such as land use, soil, and geology. Data are sufficient, and the relation is pronounced enough, to indicate trapping of suspended sediment by Livingston Reservoir.

Texas↗

USGS2022

Areas contributing recharge to priority wells in valley-fill aquifers in the Neversink River and Rondout Creek drainage basins, New York

In southeastern New York, the villages of Ellenville, Wurtsboro, Woodridge, the hamlet of Mountain Dale, and surrounding communities in the Neversink River and Rondout Creek drainage basins rely on wells that pump groundwater from valley-fill glacial aquifers for public water supply. Glacial aquifers are vulnerable to contamination because they are highly permeable and have a shallow depth to water table. To protect the quality of these water resources, water managers need accurate information about the areas that contribute recharge to production wells that pump from these aquifers. The New York State Department of Environmental Conservation and the New York State Department of Health designated eight priority wells in this region for which water supply protection is of primary concern. The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation and the New York State Department of Health, began an investigation in 2019 with the general objectives of (1) improving understanding of regional groundwater-flow system, (2) delineating areas contributing recharge to eight priority production wells, and (3) quantifying the uncertainty of these contributing areas in a probabilistic way that can be used to inform decision-making related to priority well source-water protection. To complete these objectives, a MODFLOW 6 groundwater model was created encompassing the eight priority wells and the surrounding flow system, which includes parts of the Neversink River and Rondout Creek Basins in Sullivan County and Ulster County, New York. The model was built using Python tools (such as flopy , modflow-setup , and sfrmaker ) that facilitate transparent and repeatable model development using existing datasets. The model parameters were estimated with a stepwise approach using an iterative ensemble smoother implementation of the Parameter ESTimation software PEST++ (version 5.0.0). We evaluated initial “best guess” parameter bounds with a prior Monte Carlo analysis. Results of the first prior Monte Carlo analysis were used to make informed adjustments to model parameter bounds (typically resulting in expanded bounds), and a second prior Monte Carlo analysis was run to identify improved ranges for model parameters during history matching. The history matching effort produced an ensemble of parameter values for the groundwater-flow model that spans the range of values within prior uncertainty bounds. The ensemble is informed by the historical observation data, within a reasonable range of uncertainty on those observations. This history-matched ensemble was used in a particle tracking Monte Carlo analysis to delineate the areas contributing recharge to priority wells. The groundwater-flow and particle tracking (MODPATH7) models were run once for each ensemble member. Deterministic contributing areas computed for each ensemble member were aggregated to produce maps showing the probability that a location contributes recharge to priority wells. Finally, the particle tracking Monte Carlo analysis was repeated for six pumping scenarios, representing a wide range of possible pumping levels, to incorporate uncertainty in future pumping rates related to population growth or other management decisions. Increasing pumping rates generally led to larger contributing recharge areas and larger areas of high probability that a location contributes recharge to priority wells. These maps show the overall uncertainty of the areas contributing recharge to priority wells in the study area and provide a tool for risk-based decision making for protection of well source water.

New York↗

USGS2007

Trinity River Basin, Texas

In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. Physical characteristics described include climate, geology, soils, vegetation, physiography, and hydrology. Cultural characteristics discussed include population distribution, land use and land cover, agricultural practices, water use, an reservoir operations. Major water-quality categories are identified and some of the implications of the environmental factors for water quality are presented.

Texas↗

USGS2005

Water-Quality Assessment of the Yellowstone River Basin, Montana and Wyoming-Water Quality of Fixed Sites, 1999-2001

The National Water-Quality Assessment Program of the U.S. Geological Survey initiated an assessment in 1997 of the quality of water resources in the Yellowstone River Basin. Water-quality samples regularly were collected during 1999-2001 at 10 fixed sites on streams representing the major environmental settings of the basin. Integrator sites, which are heterogeneous in land use and geology, were established on the mainstem of the Yellowstone River (4 sites) and on three major tributaries?Clarks Fork Yellowstone River (1 site), the Bighorn River (1 site), and the Powder River (1 site). Indicator sites, which are more homogeneous in land use and geology than the integrator sites, were located on minor tributaries with important environmental settings?Soda Butte Creek in a mineral resource area (1 site), the Tongue River in a forested area (1 site), and the Little Powder River in a rangeland area (1 site). Water-quality sampling frequency generally was at least monthly and included field measurements and laboratory analyses of fecal-indicator bacteria, major ions, dissolved solids, nutrients, trace elements, pesticides, and suspended sediment. Median concentrations of fecal coliform and Escherichia coli were largest for basins that were predominantly rangeland and smallest for basins that were predominantly forested. Concentrations of fecal coliform and Escherichia coli significantly varied by season (p-value <0.001); the smallest median concentrations were during January?March and the largest median concentrations were during April?June. Fecal-coliform concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 400 colonies per 100 milliliters in 2.6 percent of all samples. Escherichia coli concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 298 colonies per 100 milliliters for moderate use, full-body contact recreation in 7.6 percent of all samples. Variations in water type in the basin are reflective of the diverse geologic terrain in the Yellowstone River Basin. The water type of Soda Butte Creek and the Tongue River was calcium bicarbonate. These two sites are in forested and mountainous areas where igneous rocks and Paleozoic-era and Mesozoic-era sedimentary rocks are the dominant geologic groups. The water type of the Little Powder River was sodium sulfate. The Little Powder River originates in the plains, and geology of the basin is nearly homogenous with Tertiary-period sedimentary rocks. Water type of the Yellowstone River changed from a mixed-cation bicarbonate type upstream to a mixed-cation sulfate type downstream. Dissolved-solids concentrations ranged from fairly dilute in Soda Butte Creek, which had a median concentration of 118 milligrams per liter, to concentrated in the Little Powder River, which had a median concentration of 2,840 milligrams per liter. Nutrient concentrations generally were small and reflect the relatively undeveloped conditions in the basin; however, some correlations were made with anthropogenic factors. Median dissolved-nitrate concentrations in all samples from the fixed sites ranged from 0.04 milligram per liter to 0.54 milligram per liter. Flow-weighted mean dissolved-nitrate concentrations were positively correlated with increasing agricultural land use and rangeland on alluvial deposits upstream from the sites and negatively correlated with increasing forested land. Ammonia concentrations generally were largest in samples collected from the Yellowstone River at Corwin Springs, Montana, which is downstream from Yellowstone National Park and receives discharge from geothermal waters that are high in ammonia. Median total-phosphorus concentrations ranged from 0.007 to 0.18 milligram per liter. Median total-phosphorus concentrations exceeded the U.S. Environmental Protection Agency's recommended goal of 0.10 milligram per liter for preventing nuisance plant growth for samples collec

Scientific Investigations Report↗

USGS2022

Data sources and methods for digital mapping of eight valley-fill aquifer systems in upstate New York

Digital hydrogeologic maps were developed in eight study areas in upstate New York by the U.S. Geological Survey in cooperation with the New York State Department of Environmental Conservation. The digital maps define the hydrogeologic framework of the valley-fill aquifers and surrounding till-covered uplands in the vicinity of the villages of Ellenville and Wurtsboro and hamlets of Woodbourne and South Fallsburg in Sullivan and Ulster Counties, town of Greene in Chenango County, city of Cortland and town of Cincinnatus in Cortland County, city of Jamestown in Chautauqua County, city of Olean and village of Ellicottville in Cattaraugus County, and villages of Fishkill and Wappinger Falls in Dutchess County. The hydrogeologic framework provided the foundation for groundwater-flow models that were used in the delineation of areas contributing groundwater flow to production wells screened in four of the eight valley-fill aquifers considered in this study. The hydrogeologic framework for the other four study areas was developed for potential future use in groundwater contributing-area studies. Data used in the creation of all digital surfaces and thicknesses included published surficial geology; aquifer maps and hydrogeologic sections; light detection and ranging (lidar) datasets; the Soil Survey Geographic Database; and lithologic well logs from the National Water Information System, New York State Department of Environmental Conservation, New York State Department of Transportation, and Empire State Organized Geologic Information System databases. Digital maps of the surficial geology; thickness of the surficial sand and gravel aquifers; and tops of the confining lacustrine silt and clay units, confined sand and gravel aquifers, and bedrock surfaces were created by using ArcGIS (a geographic information system). All surfaces and thicknesses were generated by using one of the following ArcGIS interpolation tools: Topo to Raster, Natural Neighbors, Kriging, or Empirical Bayesian Kriging. The datasets developed in this study provide a greater understanding of the underlying hydrogeologic framework in glacial valley-fill aquifers and can be applied in the evaluation of groundwater-supply development and protection.

New York↗

USGS2009

The Longview/Lakeview barite deposits, southern National Petroleum Reserve, Alaska (NPRA) — Potential-field models and preliminary size estimates

Longview and Lakeview are two of the larger stratiform barite deposits hosted in Mississippian Akmalik Chert in the Cutaway Basin area (Howard Pass C-3 quadrangle) of the southern National Petroleum Reserve, Alaska (NPRA). Geologic studies for the South NPRA Integrated Activity Plan and Environmental Impact Statement process included an attempt to evaluate the possible size of barite resources at Longview and Lakeview by using potential-field geophysical methods (gravity and magnetics). Gravity data from 227 new stations measured by the U.S. Geological Survey, sparse regional gravity data, and new, high-resolution aeromagnetic data were forward modeled simultaneously along seven profiles perpendicular to strike and two profiles along strike of the Longview and Lakeview deposits. These models indicate details of the size and shape of the barite deposits and suggest thicknesses of 15 to 24 m, and 9 to 24 m for the Longview and Lakeview deposits, respectively. Two groups of outcrops span 1.8 km of strike length and are likely connected below the surface by barite as much as 10 m thick. Barite of significant thickness (>-5 m) is unlikely to occur north of the presently known exposures of the Longview deposit. The barite bodies have irregular (nonplanar) bases suggestive of folding; northwest-trending structures of small apparent offset cross strike at several locations. Dip of the barite is 10 to 25 degrees to the southeast. True width of the bodies (the least certain dimension) is estimated to be 160 to 200 m for Longview and 220 to 260 m for Lakeview. The two bodies contain a minimum of 4.5 million metric tons of barite and more than 38 million metric tons are possible. Grades of the barite are relatively high, with high specific gravities and low impurities. The potential for the Cutaway Basin to host economically minable quantities of barite is uncertain. Heavy-mineral concentrate samples from streams in the area, trace-element analyses, and physicalproperty measurements of bulk samples derived from trenching or drilling would be valuable for future assessment work.

Alaska↗

USGS2016

Development of a CE-QUAL-W2 temperature model for Crystal Springs Lake, Portland, Oregon

During summer 2014, lake level, streamflow, and water temperature in and around Crystal Springs Lake in Portland, Oregon, were measured by the U.S. Geological Survey and the City of Portland Bureau of Environmental Services to better understand the effect of the lake on Crystal Springs Creek and Johnson Creek downstream. Johnson Creek is listed as an impaired water body for temperature by the Oregon Department of Environmental Quality (ODEQ), as required by section 303(d) of the Clean Water Act. A temperature total maximum daily load applies to all streams in the Johnson Creek watershed, including Crystal Springs Creek. Summer water temperatures downstream of Crystal Springs Lake and the Golf Pond regularly exceed the ODEQ numeric criterion of 64.4 °F (18.0 °C) for salmonid rearing and migration. To better understand temperature contributions of this system, the U.S. Geological Survey developed two-dimensional hydrodynamic water temperature models of Crystal Springs Lake and the Golf Pond. Model grids were developed to closely resemble the bathymetry of the lake and pond using data from a 2014 survey. The calibrated models simulated surface water elevations to within 0.06 foot (0.02 meter) and outflow water temperature to within 1.08 °F (0.60 °C). Streamflow, water temperature, and lake elevation data collected during summer 2014 supplied the boundary and reference conditions for the model. Measured discrepancies between outflow and inflow from the lake, assumed to be mostly from unknown and diffuse springs under the lake, accounted for about 46 percent of the total inflow to the lake. Model simulations (scenarios) were run with lower water surface elevations in Crystal Springs Lake and increased shading to the lake to assess the relative effect the lake and pond characteristics have on water temperature. The Golf Pond was unaltered in all scenarios. The models estimated that lower lake elevations would result in cooler water downstream of the Golf Pond and shorter residence times in the lake. Increased shading to the lake would also provide substantial cooling. Most management scenarios resulted in a decrease in 7-day average of daily maximum values by about 2.0– 4.7 °F (1.1 –2.6 °C) for outflow from Crystal Springs Lake during the period of interest. Outflows from the Golf Pond showed a net temperature reduction of 0.5–2.7 °F (0.3–1.5 °C) compared to measured values in 2014 because of solar heating and downstream warming in the Golf Pond resulting from mixing with inflow from Reed Lake.

Oregon↗

USGS2006

Performance assessments of nuclear waste repositories: A dialogue on their value and limitations

Performance Assessment (PA) is the use of mathematical models to simulate the long-term behavior of engineered and geologic barriers in a nuclear waste repository; methods of uncertainty analysis are used to assess effects of parametric and conceptual uncertainties associated with the model system upon the uncertainty in outcomes of the simulation. PA is required by the U.S. Environmental Protection Agency as part of its certification process for geologic repositories for nuclear waste. This paper is a dialogue to explore the value and limitations of PA. Two “skeptics” acknowledge the utility of PA in organizing the scientific investigations that are necessary for confident siting and licensing of a repository; however, they maintain that the PA process, at least as it is currently implemented, is an essentially unscientific process with shortcomings that may provide results of limited use in evaluating actual effects on public health and safety. Conceptual uncertainties in a PA analysis can be so great that results can be confidently applied only over short time ranges, the antithesis of the purpose behind long-term, geologic disposal. Two “proponents” of PA agree that performance assessment is unscientific, but only in the sense that PA is an engineering analysis that uses existing scientific knowledge to support public policy decisions, rather than an investigation intended to increase fundamental knowledge of nature; PA has different goals and constraints than a typical scientific study. The “proponents” describe an ideal, sixstep process for conducting generalized PA, here called probabilistic systems analysis (PSA); they note that virtually all scientific content of a PA is introduced during the model-building steps of a PSA, they contend that a PA based on simple but scientifically acceptable mathematical models can provide useful and objective input to regulatory decision makers. The value of the results of any PA must lie between these two views and will depend on the level of knowledge of the site, the degree to which models capture actual physical and chemical processes, the time over which extrapolations are made, and the proper evaluation of health risks attending implementation of the repository. The challenge is in evaluating whether the quality of the PA matches the needs of decision makers charged with protecting the health and safety of the public.

Risk Analysis↗

USGS2009

Web GIS in practice VII: stereoscopic 3-D solutions for online maps and virtual globes

Because our pupils are about 6.5 cm apart, each eye views a scene from a different angle and sends a unique image to the visual cortex, which then merges the images from both eyes into a single picture. The slight difference between the right and left images allows the brain to properly perceive the 'third dimension' or depth in a scene (stereopsis). However, when a person views a conventional 2-D (two-dimensional) image representation of a 3-D (three-dimensional) scene on a conventional computer screen, each eye receives essentially the same information. Depth in such cases can only be approximately inferred from visual clues in the image, such as perspective, as only one image is offered to both eyes. The goal of stereoscopic 3-D displays is to project a slightly different image into each eye to achieve a much truer and realistic perception of depth, of different scene planes, and of object relief. This paper presents a brief review of a number of stereoscopic 3-D hardware and software solutions for creating and displaying online maps and virtual globes (such as Google Earth) in "true 3D", with costs ranging from almost free to multi-thousand pounds sterling. A practical account is also given of the experience of the USGS BRD UMESC (United States Geological Survey's Biological Resources Division, Upper Midwest Environmental Sciences Center) in setting up a low-cost, full-colour stereoscopic 3-D system.

International Journal of Health Geographics↗

USGS2026

Investigation of drivers and sources of potential harmful algal blooms in Lake Anna, Virginia, 2023-24

Algal blooms in freshwater reservoirs are an increasing concern because of the risk to aquatic ecosystem health, recreational use, and water quality. Among the taxa that comprise an algal bloom, cyanobacteria are of particular concern due to the potential to produce toxic compounds which can cause acute and chronic illness in humans if ingested through contaminated water or shellfish. When toxins are above a toxin-specific threshold in the water column, the Commonwealth of Virginia categorizes the bloom as a harmful algal bloom (HAB), distinguishing it from an algal bloom without toxins present. Toxins are of particular concern in bodies of water which serve as major recreational areas, such as Lake Anna in central Virginia. Lake Anna is a 27 km-long and 47 km2 reservoir in central Virginia. Since the Commonwealth of Virginia revised the HAB monitoring framework in 2018, algal bloom advisories for potentially toxigenic blooms have been issued in the western, riverine zone of the reservoir. There were detections of microcystin and anatoxin production but no detections of cylindrospermopsin and saxitoxin production in Lake Anna; however, toxin concentrations were low, at values less than 0.65 µg/L. In 2023, the U.S. Geological Survey, in cooperation with Virginia Department of Environmental Quality, initiated a 19-month intensive and extensive study of western Lake Anna and its tributaries (North Anna River and Pamunkey Creek) to (1) characterize the algal community, biomass, and toxin production; (2) identify potential drivers leading to algal bloom initiation, persistence, and decline; and (3) assess the primary sources of the drivers contributing to algal blooms. Continuous and discrete monitoring of water quality within the lake, watershed inputs, meteorological conditions, and algal communities were monitored. Multiple modeling scenarios identified that the formation and persistence of algal blooms in Lake Anna are driven by interactions among chemical, macro- and micronutrient, and physical factors. Key drivers include total nitrogen, total phosphorus, water temperature, suspended sediment concentration, wind speed, copper, iron, molybdenum, nickel, sodium, and alkalinity. During this study, winter stormflow events delivered the highest loading of macro- and micronutrients from the tributaries to the lake. The lake is a sink for these nutrients in the water column or in the lake-bed sediments. During high-occupancy and recreation periods on the lake in the summer months, boating activity can promote internal loading by the resuspension of the lake-bed sediments, thereby increasing the nutrient availability for algal uptake. Thermal stratification and hypoxic conditions were observed, which can contribute to the passive release of nutrients into the water column, further facilitating algal bloom proliferation. These processes may create a positive feedback loop that supports the formation, persistence, and annual recurrence of algal blooms in the western region of Lake Anna. Continued water-quality monitoring of early warning indicators may improve the detection and forecasting of algal growth in the lake and help managers proactively manage water quality and algal growth.

EarthArXiv↗

USGS2009

A centennial tribute, 1906-2006: History of U.S. Geological Survey streamgaging activities for the Suwannee River at White Springs, Florida

For centuries, the banks of the Suwannee River at White Springs were considered a sacred ground where people sought refuge in its 'healing waters'. Many believed that the mineral-enriched waters cured illnesses. The U.S. Geological Survey began continuous streamgaging activities at White Springs, Florida, in 1906 after an increase in congressional appropriations and rapid town development due to growing tourism and residential population. In 1906, streamgage data was a once-per-day gage reading that were handwritten in a water-level booklet by a local observer with discharge measurements taken every 6 to 8 weeks by a hydrographer. In 2006, real-time data were recorded at 1-hour increments and transmitted to U.S. Geological Survey computer networks using the Geostationary Operational Environmental Satellite, thus enabling the general public to access readings within minutes of the actual measurement. Additional data and measurements are taken and made available for high or low flows that occur during significant floods and droughts. The gage at White Springs has recorded several historic hydrologic events that affected the Suwannee River and surrounding areas. Major droughts include those during 1931-35, 1949-57, and 1998-2002. Severe floods occurred in 1948, 1973, and 2004. On April 10, 1973, the discharge was 38,100 cubic feet per second, which is the highest recorded discharge for the period of record. A flood of this magnitude is expected at a recurrence interval of about once every 200 to 500 years.

Florida↗

USGS2018

Nearshore single-beam bathymetry data collected in 2015, Dauphin Island, Alabama

Dauphin Island, Alabama, is a barrier island located in the northern Gulf of Mexico that supports local residences, tourism, commercial infrastructure, and historic Fort Gaines. During the past decade, Dauphin Island was affected by several major hurricanes—Hurricanes Ivan (2004), Katrina (2005), and Isaac (2012)—and storms, along with sea-level rise, continue to present a threat to island stability. State and Federal managers are using a scientific approach to identify, formulate, and implement a long-term plan to provide restoration options for Dauphin Island, thereby helping increase its resilience against future storms and sea-level rise. Island morphology, including current bathymetry and shoreline data, is one scientific domain being investigated in an effort to produce a comprehensive restoration plan funded by an interagency grant from the National Fish and Wildlife Foundation Gulf Environmental Benefit Fund . In August 2015, the U.S. Geological Survey ( USGS ) St. Petersburg Coastal and Marine Science Center ( SPCMSC ), in cooperation with the U.S. Army Corps of Engineers at the U.S. Army Engineer Research and Development Center, Mobile District, and the State of Alabama, conducted bathymetric surveys of the nearshore waters surrounding Dauphin Island. This report provides a detailed methodology for the data acquisition and post-processing of 1,165-line kilometers (km) of single-beam bathymetry data collected under the USGS–SPCMSC Alabama Barrier Island Restoration Study . These data were acquired and processed under USGS field activity number 2015–326–FA . Data are provided in three datums: (1) the International Terrestrial Reference Frame of 2000, ellipsoid height (from –47.04 meters (m) to –29.36 m); (2) the North American Datum of 1983, CORS96 realization (NAD83 (CORS96)) horizontal, and the North American Vertical Datum 1988 GEOID12A vertical (from –0.24 m to –17.33 m); and (3) NAD83 (CORS96) horizontal, and mean lower low water vertical (from –0.12 m to –17.93 m). The x,y,z point datasets, trackline shapefiles, digital and handwritten Field Activity Collection Systems logs, one 50-m digital elevation model, and formal Federal Geographic Data Committee metadata are obtainable from the Data Downloads page or the associated USGS data release .

Alabama↗

USGS2008

Occurrence of endocrine active compounds and biological responses in the Mississippi River— Study design and data, June through August 2006

Concern that selected chemicals in the environment may act as endocrine active compounds in aquatic ecosystems is widespread; however, few studies have examined the occurrence of endocrine active compounds and identified biological markers of endocrine disruption such as intersex occurrence in fish longitudinally in a river system. This report presents environmental data collected and analyzed by the U.S. Geological Survey, Minnesota Pollution Control Agency and St. Cloud State University as part of an integrated biological and chemical study of endocrine disruption in fish in the Mississippi River. Data were collected from water, bed sediment, and fish at 43 sites along the river from the headwaters at Lake Itasca to 14 miles downstream from Brownsville, Minnesota during June through August 2006. Twenty-four individual compounds were detected in water samples, with cholesterol, atrazine, N,N-diethyl-meta-toluamide, metolachlor, and hexahydrohexamethylcyclopentabenzopyran detected most frequently (in at least 10 percent of the samples). The number of compounds detected in water per site ranged from 0 to 8. Forty individual compounds were detected in bed-sediment samples. The most commonly detected compounds (in at least 50 percent of the samples) were indole, beta-sitosterol, cholesterol, beta-stigmastanol, 3-methyl-1H-indole, p-cresol, pyrene, phenol, fluoranthene, 3-beta coprostanol, benzo[a]pyrene, acetophenone, and 2,6-dimethylnaphthalene. The total number of detections in bed sediment (at a site) ranged from 3 to 31. The compounds NP1EO, NP2EO, and 4-nonylphenol were detected in greater than 10 percent of the samples. Most (80 percent) female fish collected had measurable concentrations of vitellogenin. Vitellogenin also was detected in 62, 63, and 33 percent of male carp, smallmouth bass, and redhorse, respectively. The one male walleye sample plasma sample analyzed had a vitellogenin detection. Vitellogenin concentrations were lower in male fish (not detected to 10.80 micrograms per milliliter) than female fish (0.04 to 248,079 micrograms per milliliter). Gonadosomatic Index values ranged from 0.02 to 7.49 percent among all male fish and were greater for male carp than for the other three species. No intersex (oocytes present in testes tissue) was found in any male fish sampled.

Minnesota, Wisconsin↗

USGS2015

Surface geophysics and porewater evaluation at the Lower Darby Creek Area Superfund Site, Philadelphia, Pennsylvania, 2013

In cooperation with the U.S. Environmental Protection Agency (EPA), Region 3, the U.S. Geological Survey (USGS) is participating in an ongoing study to aid in the identification of subsurface heterogeneities that may act as preferential pathways for contaminant transport in and around the Lower Darby Creek Area (LDCA) Superfund Site, Philadelphia Pa. Lower Darby Creek, which flows into the Delaware River, borders the western part of the former landfill site. In 2013, the USGS conducted surface geophysics measurements and stream porewater sampling to provide additional data for EPA’s site characterization. This report contains data collected from field measurements of direct current (DC) resistivity, frequency-domain electromagnetic (FDEM) surveys, and stream porewater specific conductance (SC).

Pennsylvania↗

USGS2002

Llano Grande Lake bottom sediments; a chronicle of water-quality changes in the Arroyo Colorado, South Texas, 1989-2001

The Arroyo Colorado, an ancient channel of the Rio Grande, extends 90 miles from Mission, Tex., to the Laguna Madre. The Arroyo Colorado flows through areas of intense agricultural cultivation and through important habitat for migrating birds and other wildlife, including several wildlife sanctuaries and refuges. The above-tidal segment of the Arroyo Colorado is included in the State of Texas 2000 Clean Water Act 303(d)1 list in part because of elevated concentrations of the hydrophobic legacy pollutants DDE (a DDT breakdown product), chlordane, and toxaphene in fish tissue. This report addresses three questions: Do legacy pollutants (organochlorine compounds, major and trace elements) occur in the Arroyo Colorado at present and at what concentrations? How has the occurrence of selected legacy pollutants in the Arroyo Colorado changed over time? Are current concentrations of legacy pollutants in bottom sediments at levels of concern for the health of aquatic biota? To answer these questions, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA), collected and analyzed a sediment core from Llano Grande Lake on the Arroyo Colorado (fig. 1). Sediment cores can be used to reconstruct historical trends in concentrations of hydrophobic contaminants (Eisenreich and others, 1989; Van Metre and others, 1997, 2000). The lake is part of the Rio Grande delta drainage system (fig. 1). The lake is 6 miles long and has a maximum width of 600 feet.

Texas↗