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At least 721 records · Page 40Linked to original sources

USGS1976

Hydrology of lakes in the Minneapolis-Saint Paul Metropolitan Area: A summary of available dat

Data were collected and summarized on the hydrology and hydrogeology of 949 lakes, 10 acres (4 hectares) or larger, in the Minneapolis-St. Paul metropolitan area, Minnesota. Eight tables totaling over 100 pages present data on location, depth, area, lake level, ecological and game-management classification, inflowing and outflowing streams, soils, bedrock type, water added to or take from lake, and reported lake-related problems. SYSTEM 2000, a generalized computer data-base management system, was used to organize the data and prepare the tables. SYSTEM 2000 provides powerful capabilities for future retrieval and analyses of the data. The data base is available to potential users so that questions not implicitly anticipated in the preparation of the published tables can be answered readily, and the user can retrieve data in tabular or other forms to meet his particular needs.

Minnesota↗

USGS2018

Relating cyanobacteria and physicochemical water-quality properties in Willow Creek Lake, Nebraska, 2012–14

Cyanobacteria (also referred to as blue-green algae) are naturally present members of phytoplankton assemblages that may detract from beneficial uses of water because some strains produce cyanotoxins that pose health hazards to people and animals. Cyanobacteria populations observed in Willow Creek Lake during 2012 through 2014 were compared to external nutrient loading from the Willow Creek drainage basin and several other physicochemical properties within the lake, including internal nutrient loading. This report is part of a cooperative study between the U.S. Geological Survey, the Lower Elkhorn Natural Resources District, the Nebraska Department of Environmental Quality, the Nebraska Game and Parks Commission, the Nebraska Department of Natural Resources, the Nebraska Environmental Trust, and the University of Nebraska–Lincoln. Cyanobacteria concentrations were quantified using weekly microcystin sampling, intermittent algal taxonomy, and hourly in-situ phycocyanin measurements. External and internal nutrient loads, lake water physical characteristics, and local meteorological conditions were evaluated as potential causes of cyanobacterial blooms. A water balance approach that estimated Willow Creek Lake inflow and outflow volumes identified Willow Creek as the major inflow and groundwater flux as the major outflow for the lake. Nutrient concentrations from several water sources were quantified and combined with flow volumes to compute nutrient loads during the study period. Surface flows contributed most external nutrients to the lake, whereas lake nutrients were exported during groundwater losses. The main stem of Willow Creek accounted for most nitrate loads to the lake, whereas total Kjeldahl nitrogen, total phosphorus, and phosphate loads to the lake were more evenly distributed between Willow Creek and the North Tributary, a smaller drainage. Sediment core incubations determined internal phosphorus loading was a negligible component of the overall nutrient load to the lake. Cyanobacterial responses were compared to nutrient loads and other external factors that could potentially affect algal growth. A series of univariate comparisons were made by plotting those factors against phycocyanin using biweekly summaries of each and a multivariate model that incorporated seasonality and cumulative nitrate loading. Although the multivariate model only incorporated cumulative nitrate, both nitrogen and phosphorus are likely contributing to cyanobacterial population growth, and management efforts may benefit from the recognition of differences in nutrient loading characteristics between the monitored basins.

Nebraska↗

USGS2019

A comparison of hydrocarbon-related landscape disturbance patterns along the New York-Pennsylvania border, 2004–2013

Executive Summary The New York-Pennsylvania area has a long history of hydrocarbon extraction, and the addition of shale gas extraction methods contributes to landscape disturbance borne by previously developed oil and non-shale gas resources. The main unconventional extraction method used to extract shale gas from the Marcellus Shale located in New York and Pennsylvania is hydraulic fracturing, or “fracking,” although other conventional methods are used extensively. All forms of hydrocarbon extraction disturb the surrounding landscape to some extent, primarily in the form of land clearance and degradation, road construction, and pipeline development, although the effects of these disturbances are not fully understood. In this study, landscape-change metrics and indicators are used to analyze change in a 10-county region along the New York-Pennsylvania border—the New York counties of Allegany, Steuben, Chemung, Tioga, and Broome, and the Pennsylvania counties of McKean, Potter, Tioga, Bradford, and Susquehanna. This 10-county region was selected due to the differences in policies between the States of New York and Pennsylvania. While fracking occurred extensively in Pennsylvania over the past 10 years or more, the State of New York issued a temporary moratorium against hydraulic fracturing in 2010—citing repercussions that might affect air quality, water quality, and public health—and officially banned hydraulic fracturing in June 2015. The quantification of landscape disturbance due to hydrocarbon extraction activities is presented in this report as land-use and land-cover (LULC) change between 2004 and 2013 and defined using specific disturbance categories (including well sites, roads, and pipelines) to compare the disturbances and changes, by county, on both sides of the New York-Pennsylvania border. The quantification was accomplished by gathering the signatures of disturbance from high-resolution aerial images, comparing the derived totals of disturbance, and then computing landscape metrics in a geographic information system (GIS) environment. The collected data represent a summation of landscape disturbance from oil and gas development, as some of the data represented were established decades earlier. The Analytical Tools Interface for Landscape Assessments (ATtILA) software was used to calculate land-cover area and landscape metrics for each shale gas, non-shale gas, oil, and other infrastructure types associated with hydrocarbons across each county and both five-county regions in the study area. The three primary metrics used to describe changes in forest structure were (1)forest area, (2) interior forest area, and (3) forest edge area. The changes in metrics were subsequently evaluated using the Pearson correlation coefficient. Overall, the disturbed-area footprint in the Pennsylvania region is considerably larger than the disturbed-area footprint in the New York region (13,687.9 hectares [ha] in Pennsylvania; 3,840.5 ha in New York). Disturbance per site is similar, with 1.2 disturbed ha per site in New York and 1.6 disturbed ha per site in Pennsylvania. In the New York-Pennsylvania 10-county region, hydrocarbon-development and extraction disturbance strongly correlate with a reduction in the percentage of forest for the entire region. This observation also appears to be true in the New York five-county region for forest area. This form of disturbance in the New York five-county region shows significantly correlated changes in forest metrics (–0.4 percent total forest area), particularly in the percentage of interior forest (–1.2 percent total area) and forest edge (+0.7 percent total area). On the other hand, gas and hydrocarbon-development and extraction disturbance (1.0 percent total area) in the Pennsylvania five-county region strongly correlates with a total decline in forest area and agricultural land area (–0.8 percent combined total area) but not with either land-cover class separately.

New York, Pennsylvania↗

USGS1984

Streamflow characteristics of the Yellowstone River basin, Montana, through September 1982

Statistical summaries of streamflow data for selected stream-gaging sites are presented in this report to aid in appraising streamflow in the Yellowstone River basin. Streamflow records are presented for 71 gaging stations for the period of record. Streamflow record collection in the Yellowstone River basin began in 1889. For each gaging station selected for this report, a brief description is given for station location, drainage area, period of record, revisions of previously published records, type and history of gages, regulation and diversions, average discharge, and extremes of discharge. This information is followed by tables of monthly and annual flow statistics, flood-frequency data, low-flow and high-flow frequency data, and flow-duration data. (USGS)

Water-Resources Investigations Report↗

USGS2014

Uncertainty and extreme events in future climate and hydrologic projections for the Pacific Northwest: providing a basis for vulnerability and core/corridor assessments

The purpose of this project was to (1) provide an internally-consistent set of downscaled projections across the Western U.S., (2) include information about projection uncertainty, and (3) assess projected changes of hydrologic extremes. These objectives were designed to address decision support needs for climate adaptation and resource management actions. Specifically, understanding of uncertainty in climate projections – in particular for extreme events – is currently a key scientific and management barrier to adaptation planning and vulnerability assessment. The new dataset fills in the Northwest domain to cover a key gap in the previous dataset, adds additional projections (both from other global climate models and a comparison with dynamical downscaling) and includes an assessment of changes to flow and soil moisture extremes. This new information can be used to assess variations in impacts across the landscape, uncertainty in projections, and how these differ as a function of region, variable, and time period. In this project, existing University of Washington Climate Impacts Group (UW CIG) products were extended to develop a comprehensive data archive that accounts (in a reigorous and physically based way) for climate model uncertainty in future climate and hydrologic scenarios. These products can be used to determine likely impacts on vegetation and aquatic habitat in the Pacific Northwest (PNW) region, including WA, OR, ID, northwest MT to the continental divide, northern CA, NV, UT, and the Columbia Basin portion of western WY New data series and summaries produced for this project include: 1) extreme statistics for surface hydrology (e.g. frequency of soil moisture and summer water deficit) and streamflow (e.g. the 100-year flood, extreme 7-day low flows with a 10-year recurrence interval); 2) snowpack vulnerability as indicated by the ratio of April 1 snow water to cool-season precipitation; and, 3) uncertainty analyses for multiple climate scenarios.

Arizona, California, Colorado, Idaho, Montana, Nev↗

USGS1977

Annual summary of ground-water conditions in Arizona, spring 1976 to spring 1977

Two small-scale maps of Arizona show (1) pumpage of ground water by areas and (2) the status of the ground-water inventory in the State. The main map, which is at a scale of 1:500,000, shows potential well production, depth of water in selected wells in spring 1977, and change in water level in selected wells from 1972 to 1977. The brief text that accompanies the maps summarizes the current ground-water conditions in the State. The withdrawal of ground water was about 5.5 million acre-feet in Arizona in 1976 of which about 4.7 million acre-feet was used for the irrigation. The Salt River Valley and the lower Santa Cruz basin are the largest agricultural areas in the State. For 1972-76, ground-water withdrawal in the two areas was about 8.2 to 4.9 million acre-feet, respectively, and, in general, water levels are declining. Other areas in which ground-water withdrawals have caused large water-level declines are the Willcox, San Simon, upper Santa Cruz, Avra Valley, Gila Bend, Harquahala Plains, and McMullen Valley areas. (Woodard-USGS)

Arizona↗

USGS2020

Groundwater availability of the Northern High Plains aquifer in Colorado, Kansas, Nebraska, South Dakota, and Wyoming

Executive Summary The Northern High Plains aquifer underlies about 93,000 square miles of Colorado, Kansas, Nebraska, South Dakota, and Wyoming and is the largest subregion of the nationally important High Plains aquifer. Irrigation, primarily using groundwater, has supported agricultural production since before 1940, resulting in nearly $50 billion in sales in 2012. In 2010, the High Plains aquifer had the largest groundwater withdrawals of any major aquifer system in the United States. Nearly one-half of those withdrawals were from the Northern High Plains aquifer, which has little hydrologic interaction with parts of the aquifer farther south. Land-surface elevation ranges from more than 7,400 feet (ft) near the western edge to less than 1,100 ft near the eastern edge. Major stream primarily flow west to east and include the Big Blue River, Elkhorn River, Loup River, Niobrara River, Republican River and Platte River with its two forks—the North Platte River and South Platte River. Population in the Northern High Plain aquifer area is sparse with only 2 cities having a population greater than 30,000. Droughts across much of the area from 2001 to 2007, combined with recent (2004–18) legislation, have heightened concerns regarding future groundwater availability and highlighted the need for science-based water-resource management. Groundwater models with the capability to provide forecasts of groundwater availability and related stream base flows from the Northern High Plains aquifer were published recently (2016) and were used to analyze groundwater availability. Stream base flows are generally the dominant component of total streamflow in the Northern High Plains aquifer, and total streamflows or shortages thereof define conjunctive management triggers, at least in Nebraska. Groundwater availability was evaluated through comparison of aquifer-scale water budgets compared for periods before and after major groundwater development and across selected future forecasts. Groundwater-level declines and the forecast amount of groundwater in storage in the aquifer also were examined. Major Findings Aquifer losses to irrigation withdrawals increased greatly from 1940 to 2009 and were the largest average 2000–9 outflow (49 percent of total). Basin to basin groundwater flows were not a large part of basin water budgets. Development of irrigated land and associated withdrawals were not uniform across the Northern High Plains aquifer, and different parts of the Northern High Plains aquifer responded differently to agricultural development. For the Northern High Plains aquifer, areas with high recharge and low evapotranspiration had the most streamflow, and most streams only remove water from the aquifer. Results of a baseline future forecast indicated that groundwater levels declined overall, indicating an overdraft of the aquifer when climate was about average and agricultural development was held at the same state as 2009. Results of two human stresses future forecasts indicated that increases of 13 percent or 23 percent in agricultural development, mostly near areas of previous development, caused increases in groundwater pumping of 8 percent or 11 percent, and resulted in continued groundwater-level declines, at rates 0.3 or 0.5 million acre-feet per year larger than the baseline forecast. Results of environmental stresses forecasts (generated from two downscalings of global climate model outputs) compared with the baseline forecast indicated that even though annual precipitation was nearly the same, differences in temperature and a redistribution of precipitation from the spring to the growing season (from about May 1 through September 30), created a large (12–15 percent) decrease in recharge to the aquifer. For the two environmental stresses forecasts, temperature and precipitation were distributed about the same among basins of the Northern High Plains aquifer, but the amounts were different.

Colorado, Kansas, Nebraska, South Dakota, Wyoming↗

USGS2017

Measuring urban water conservation policies: Toward a comprehensive index

This article (1) discusses existing efforts to measure water conservation policies (WCPs) in the United States (U.S.); (2) suggests general methodological guidelines for creating robust water conservation indices (WCIs); (3) presents a comprehensive template for coding WCPs; (4) introduces a summary index, the Vanderbilt Water Conservation Index (VWCI), which is derived from 79 WCP observations for 197 cities for the year 2015; and (5) compares the VWCI to WCP data extracted from the 2010 American Water Works Association (AWWA) Water and Wastewater Rates survey. Existing approaches to measuring urban WCPs in U.S. cities are limited because they consider only a portion of WCPs or they are restricted geographically. The VWCI consists of a more comprehensive set of 79 observations classified as residential, commercial/industrial, billing structure, drought plan, or general. Our comparison of the VWCI and AWWA survey responses indicate reasonable agreement ( ρ = 0.76) between the two WCIs for 98 cities where the data overlap. The correlation suggests the AWWA survey responses can provide fairly robust longitudinal WCP information, but we argue the measurement of WCPs is still in its infancy, and our approach suggests strategies for improving existing methods.

Journal of the American Water Resources Associatio↗

USGS1997

Looking for an old aerial photograph

Attempts to photograph the surface of the Earth date from the 1800's, when photographers attached cameras to balloons, kites, and even pigeons. Today, aerial photographs and satellite images are commonplace. The rate of acquiring aerial photographs and satellite images has increased rapidly in recent years. Views of the Earth obtained from aircraft or satellites have become valuable tools to Government resource planners and managers, land-use experts, environmentalists, engineers, scientists, and a wide variety of other users. Many people want historical aerial photographs for business or personal reasons. They may want to locate the boundaries of an old farm or a piece of family property. Or they may want a photograph as a record of changes in their neighborhood, or as a gift. The U.S. Geological Survey (USGS) maintains the Earth Science Information Centers (ESIC?s) to sell aerial photographs, remotely sensed images from satellites, a wide array of digital geographic and cartographic data, as well as the Bureau?s wellknown maps. Declassified photographs from early spy satellites were recently added to the ESIC offerings of historical images. Using the Aerial Photography Summary Record System database, ESIC researchers can help customers find imagery in the collections of other Federal agencies and, in some cases, those of private companies that specialize in esoteric products.

Fact Sheet↗

USGS1977

Annual summary of ground-water conditions in Arizona, spring 1975 to spring 1976

Two small-scale maps of Arizona show (1) pumpage of ground water by areas and (2) the status of the ground-water inventory in the State. A larger map of the State at a scale of 1:500,000 shows potential well production, depth to water in selected wells in spring 1976, and change in water level in selected wells from 1971 to 1976. The brief text that accompanies the maps summarizes the current ground-water conditions in the State. The withdrawal of ground water in Arizona was about 5.6 million acre-feet in 1975, of which about 4.7 million acre-feet was used for the irrigation of crops. The Salt River Valley and the lower Santa Cruz basin are the largest agricultural areas in the State. For 1971-75, ground-water withdrawal in the two areas was about 8.3 and 4.7 million acre-feet, respectively, and, in general, water levels are declining. Other areas in which ground-water withdrawals have caused large water-level declines are the Willcox, San Simon, upper Santa Cruz, Avra Valley, Gila Bend, Harquahala Plains, and McMullen Valley areas. (Woodard-USGS)

Arizona↗

USGS2007

Influence of different temporal sampling strategies on estimating total phosphorus and suspended sediment concentration and transport in small streams

Various temporal sampling strategies are used to monitor water quality in small streams. To determine how various strategies influence the estimated water quality, frequently collected water quality data from eight small streams (14 to 110 km2) in Wisconsin were systematically subsampled to simulate typically used strategies. These subsets of data were then used to estimate mean, median, and maximum concentrations, and with continuous daily flows used to estimate annual loads (using the regression method) and volumetrically weighted mean concentrations. For each strategy, accuracy and precision in each summary statistic were evaluated by comparison with concentrations and loads of total phosphorus and suspended sediment estimated from all available data. The most effective sampling strategy depends on the statistic of interest and study duration. For mean and median concentrations, the most frequent fixed period sampling economically feasible is best. For maximum concentrations, any strategy with samples at or prior to peak flow is best. The best sampling strategy to estimate loads depends on the study duration. For one-year studies, fixed period monthly sampling supplemented with storm chasing was best, even though loads were overestimated by 25 to 50 percent. For two to three-year load studies and estimating volumetrically weighted mean concentrations, fixed period semimonthly sampling was best.

Wisconsin↗

USGS2016

National Park Service Vegetation Mapping Inventory Program: Natchez Trace Parkway vegetation mapping project report

The National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program is an effort to classify, describe, and map existing vegetation of national park units for the NPS Natural Resource Inventory and Monitoring (I&M) Program. The NPS VMI Program is managed by the NPS I&M Division and provides baseline vegetation information to the NPS Natural Resource I&M Program. The U.S. Geological Survey Upper Midwest Environmental Sciences Center, NatureServe, NPS Gulf Coast Network, and NPS Natchez Trace Parkway (NATR; also referred to as Parkway) have completed vegetation classification and mapping of NATR for the NPS VMI Program. Mappers, ecologists, and botanists collaborated to affirm vegetation types within the U.S. National Vegetation Classification (USNVC) of NATR and to determine how best to map them by using aerial imagery. Analyses of data from 589 vegetation plots had been used to describe an initial 99 USNVC associations in the Parkway; this classification work was completed prior to beginning this NATR vegetation mapping project. Data were collected during this project from another eight quick plots to support new vegetation types not previously identified at the Parkway. Data from 120 verification sites were collected to test the field key to vegetation associations and the application of vegetation associations to a sample set of map polygons. Furthermore, data from 900 accuracy assessment (AA) sites were collected (of which 894 were used to test accuracy of the vegetation map layer). The collective of all these datasets resulted in affirming 122 USNVC associations at NATR. To map the vegetation and open water of NATR, 63 map classes were developed. including the following: 54 map classes represent natural (including ruderal) vegetation types in the USNVC, 5 map classes represent cultural (agricultural and developed) vegetation types in the USNVC, 3 map classes represent nonvegetation open-water bodies (non-USNVC), and 1 map class represents landscapes that had received tornado damage a few months prior to the time of aerial imagery collection. Features were interpreted from viewing 4-band digital aerial imagery by means of digital onscreen three-dimensional stereoscopic workflow systems in geographic information systems. (The aerial imagery was collected during mid-October 2011 for the northern reach of the Parkway and mid-November 2011 for the southern reach of the Parkway to capture peak leaf-phenology of trees.) The interpreted data were digitally and spatially referenced, thus making the spatial-database layers usable in geographic information systems. Polygon units were mapped to either a 0.5 hectare (ha) or 0.25 ha minimum mapping unit, depending on vegetation type or scenario. A geodatabase containing various feature-class layers and tables present the locations of USNVC vegetation types (vegetation map), vegetation plot samples, verification sites, AA sites, project boundary extent, and aerial image centers. The feature-class layer and related tables for the vegetation map provide 13,529 polygons of detailed attribute data covering 21,655.5 ha, with an average polygon size of 1.6 ha; the vegetation map coincides closely with the administrative boundary for NATR. Summary reports generated from the vegetation map layer of the map classes representing USNVC natural (including ruderal) vegetation types apply to 12,648 polygons (93.5% of polygons) and cover 18,542.7 ha (85.6%) of the map extent for NATR. The map layer indicates the Parkway to be 70.5% forest and woodland (15,258.7 ha), 0.3% shrubland (63.0 ha), and 14.9% herbaceous cover (3,221.0 ha). Map classes representing USNVC cultural types apply to 678 polygons (5.0% of polygons) and cover 2,413.9 ha (11.1%) of the map extent.

Natural Resource Report↗

USGS2020

Council monitoring and assessment program (CMAP): Common monitoring program attributes and methodologies for the Gulf of Mexico Region

Executive Summary Under the Resources and Ecosystem Sustainability, Tourist Opportunities, and Revived Economies of the Gulf Coast States Act of 2012 (RESTORE Act), the Gulf Coast Ecosystem Restoration Council (RESTORE Council or Council) is required to report on the progress of funded projects and programs. Systematic monitoring of restoration at the project-specific and programmatic-levels (i.e., watershed and Gulf of Mexico) enables consistent reporting and gives the public confidence that the restoration investments selected by the RESTORE Council will be evaluated and adaptively managed accordingly. Monitoring information that has been collected at different spatial and temporal scales can be used as the foundation to illustrate progress towards comprehensive ecosystem restoration goals and objectives that promote holistic Gulf of Mexico recovery (see ‘RESTORE Council Background’ at the beginning of this report for additional Council information). Federal, state and local agencies, universities, private industry, and non-governmental organizations (NGOs) have conducted and are conducting extensive monitoring activities around the Gulf of Mexico. In addition, each RESTORE Council-funded project will, at a minimum, perform project-specific monitoring. This collection of monitoring activities was inventoried and compiled into a framework of tools and resources by the Council-funded RESTORE Council Monitoring and Assessment Program (CMAP). CMAP was designed and funded to inventory and integrate existing water quality and habitat monitoring and mapping efforts to support discovery and accessibility of existing monitoring data and ensure the collected information is made available to support management decisions. Results of CMAP Inventory queries can be used to identify opportunities for efficiencies and support crossprogram review of performance across Gulf of Mexico ecosystem recovery efforts. The fundamental approach being used to inform the build out of the CMAP Gulf of Mexico water quality monitoring, habitat monitoring, and mapping framework includes: 1. Adopt, or construct as needed, a comprehensive inventory of existing habitat and water quality observation, monitoring, and mapping programs in the Gulf of Mexico (hereafter referred to as the “Inventory”; NOAA and USGS, 2019a); 2. Evaluate the suitability/applicability of each program and its existing and prospective data for use in restoration activities; 3. Develop a process to use the Inventory to conduct gap assessments; 4. Develop a catalog of baseline assessments conducted in the Gulf of Mexico (NOAA and USGS, 2019b); and 5. Develop a searchable monitoring information portal/database to enable access to collected information and products.

Alabama, Florida, Georgia, Louisiana, Mississippi,↗

USGS2017

Landsat and agriculture—Case studies on the uses and benefits of Landsat imagery in agricultural monitoring and production

Executive Summary The use of Landsat satellite imagery for global agricultural monitoring began almost immediately after the launch of Landsat 1 in 1972, making agricultural monitoring one of the longest-standing operational applications for the Landsat program. More recently, Landsat imagery has been used in domestic agricultural applications as an input for field-level production management. The enactment of the U.S. Geological Survey’s free and open data policy in 2008 and the launch of Landsat 8 in 2013 have both influenced agricultural applications. This report presents two primary sets of case studies on the applications and benefits of Landsat imagery use in agriculture. The first set examines several operational applications within the U.S. Department of Agriculture (USDA) and the second focuses on private sector applications for agronomic management. Information on the USDA applications is provided in the U.S. Department of Agriculture Uses of Landsat Imagery for Global and Domestic Agricultural Monitoring section of the report in the following subsections: Estimating Crop Production .—Provides an overview of how Landsat satellite imagery is used to estimate crop production, including the spectral bands most frequently utilized in this application. Monitoring Consumptive Water Use .—Highlights the role of Landsat imagery in monitoring consumptive water use for agricultural production. Globally, a significant amount of agricultural production relies on irrigation, so monitoring water resources is a critical component of agricultural monitoring. National Agricultural Statistics Service —Cropland Data Layer.—Highlights the use of Landsat imagery in developing the annual Cropland Data Layer, a crop-specific land cover classification product that provides information on more than 100 crop categories grown in the United States. Foreign Agricultural Service —Global Agricultural Monitoring.—Highlights Landsat’s role in monitoring global agricultural production. The USDA has been using Landsat imagery to monitor global agricultural production since the launch of Landsat 1 in 1972. Landsat imagery provides objective, global input for a number of USDA agricultural programs and plays an important role in economic and food security forecasting. U.S. Department of Agriculture —Satellite Imagery Archive.—Highlights a number of the experiences of the USDA in acquiring, sharing, and managing moderate resolution imagery to support the diversity of USDA operational programs. Private sector applications using Landsat imagery for agricultural management are discussed in the Landsat Imagery Use and Benefits in Field-Level Agricultural Production Management section of the report in the following subsections: Field-Level Management .—Provides an introduction to what field-level production management is and how it can be applied to agricultural management. This section explores the concept of zone mapping and how Landsat imagery can be used to identify different conditions within a field. The section also provides a case study of zone-mapping software, developed by GK Technology, Inc., that is used by numerous agricultural consultants. Putting Zone Maps to Work .—Highlights several case studies of private agricultural consultants who have been using Landsat imagery to develop zone maps for farmers. Landsat imagery is helping consultants and farmers optimize agricultural inputs, including fertilizer and seed, which leads to higher yield and economic return for the farmer. Increasing Yield .—Highlights the primary benefit of zone mapping using Landsat imagery. Using 5-year market average prices for a number of commodities, this section provides examples of how yield increases translate into higher returns for farmers.

Open-File Report↗

USGS1980

Summary of regional geology, petroleum potential, resource assessment and environmental considerations for oil and gas lease sale area #56

This report summarizes our general knowledge of the petroleum potential, as well as problems and hazards associated with development of petroleum resources in the area proposed for nominations for lease sale number 56. This area includes the U.S. eastern continental margin from the North Carolina-Virginia border south to approximately Cape Canaveral, Florida and from three miles from shore, seaward to include the upper Continental Slope and inner Blake Plateau. The area for possible sales is shown in figure 1; major physiographic features of the region are shown in figure 2. No wells have been drilled for petroleum within this proposed lease area and no significant commercial production has been obtained onshore in the Southeast Georgia Embayment. The COST GE-1 stratigraphic test well, drilled on the Continental Shelf off Jacksonville, Fla. (fig- 1), reached basement at 3,300 m. The bottom third of the section consists of dominantly continental rocks that are typically poor sources of petroleum (Scholle, 1979) and the rocks that contain organic carbon adequate for generation of petroleum at the well are seen in seismic profiles always at shallow subbottom depths, so they probably have not reached thermal maturity. However, seismic profiles indicate that the sedimentary deposits thicken markedly in a seaward direction where more of the section was deposited under marine conditions; therefore, commercial accumulations of petroleum offshore are more likely. Several potential sources of environmental hazard exist. Among the most important are hurricanes, the Gulf Stream, and earthquakes. The potential danger from high wind, waves, storm surges, and storm-driven currents associated with hurricanes is obvious. Evidence for significant bottom scour by the Gulf Stream is abundant; such scour is a threat to the stability of bottom-mounted structures. The fast-flowing water also will hamper floating drill rigs and control of drill strings. A major earthquake of about magnitude 6.8 struck Charleston in 1886; it may have been associated with a zone of active seismicity that crosses South Carolina. The likelihood of a repetition of the 1886 event is presently not predictable but a seismic hazard must be assumed to exist.

Open-File Report↗

USGS2013

Sediment distribution and hydrologic conditions of the Potomac aquifer in Virginia and parts of Maryland and North Carolina

Sediments of the heavily used Potomac aquifer broadly contrast across major structural features of the Atlantic Coastal Plain Physiographic Province in eastern Virginia and adjacent parts of Maryland and North Carolina. Thicknesses and relative dominance of the highly interbedded fluvial sediments vary regionally. Vertical intervals in boreholes of coarse-grained sediment commonly targeted for completion of water-supply wells are thickest and most widespread across the central and southern parts of the Virginia Coastal Plain. Designated as the Norfolk arch depositional subarea, the entire sediment thickness here functions hydraulically as a single interconnected aquifer. By contrast, coarse-grained sediment intervals are thinner and less widespread across the northern part of the Virginia Coastal Plain and into southern Maryland, designated as the Salisbury embayment depositional subarea. Fine-grained intervals that are generally avoided for completion of water-supply wells are increasingly thick and widespread northward. Fine-grained intervals collectively as thick as several hundred feet comprise two continuous confining units that hydraulically separate three vertically spaced subaquifers. The subaquifers are continuous northward but merge southward into the single undivided Potomac aquifer. Lastly, far southeastern Virginia and northeastern North Carolina are designated as the Albemarle embayment depositional subarea, where both coarse- and fine-grained intervals are of only moderate thickness. The entire sediment thickness functions hydraulically as a single interconnected aquifer. A substantial hydrologic separation from overlying aquifers is imposed by the upper Cenomanian confining unit. Potomac aquifer sediments were deposited by a fluvial depositional complex spanning the Virginia Coastal Plain approximately 100 to 145 million years ago. Westward, persistently uplifted granite and gneiss source rocks sustained a supply of coarse-grained sand and gravel. Immature, high-gradient braided streams deposited longitudinal bars and channel fills across the Norfolk arch subarea. By contrast, across the Salisbury and Albemarle embayment subareas, mature, medium- to low-gradient meandering streams deposited medium- to coarse-grained channel fills and point bars segregated from fine-grained overbank deposits. The Virginia depositional complex merged northward across the Salisbury embayment subarea with another complex in Maryland. Here, additional sediments were received from schist source rocks that underwent three cycles of initial uplift and rapid erosion followed by crustal stability and erosional leveling. Because of the predominance of coarse-grained sediments, transmissivity, hydraulic conductivity, and regional velocities of lateral flow through the Potomac aquifer are greatest across the Norfolk arch depositional subarea, but decrease progressively northward with increasingly fine-grained sediments. Confining units hydraulically separate the Potomac aquifer from overlying aquifers, as indicated by large vertical hydraulic gradients. By contrast, most of the Potomac aquifer internally functions hydraulically as a single interconnected aquifer, as indicated by uniformly small vertical gradients. Most fine-grained sediments within the aquifer do not hydraulically separate overlying and underlying coarse-grained sediments. Across the Salisbury embayment depositional subarea, however, hydraulic separation among the vertically spaced subaquifers is imposed by the intervening confining units. The Potomac aquifer is the largest and most heavily used source of groundwater in the Virginia Coastal Plain. Water-level declines as great as 200 feet create the potential for saltwater intrusion. Conventional stratigraphic correlation has been generally ineffective at accurately characterizing complexly distributed fluvial sediments that compose the Potomac aquifer. Consequently, the aquifer’s internal hydraulic connectivity and overall hydrologic function have not been well understood. Water-supply planning and development efforts have been hampered, and interpretations of regulatory criteria for allowable water-level declines have been ambiguous. An investigation undertaken during 2010–11 by the U.S. Geological Survey, in cooperation with the Virginia Department of Environmental Quality, provides a comprehensive regional description of the spatial distribution of Potomac aquifer sediments and their relation to hydrologic conditions. Altitudes and thicknesses of 2,725 vertical sediment intervals represent the spatial distribution of Potomac aquifer sediments in the Virginia Coastal Plain and adjacent parts of Maryland and North Carolina. Sediment intervals are designated as either dominantly coarse or fine grained and were determined by interpretation of geophysical logs and ancillary information from 456 boreholes. Sediment-interval and borehole summary statistical data indicate regional trends in sediment lithology and stratigraphic continuity, upon which three structurally based and hydrologically distinct sediment depositional subareas are designated. Broad patterns of sediment deposition over time are inferred from published sediment pollen-age data. Discrepancies in previously drawn hydrostratigraphic relations between southeastern Virginia and northeastern North Carolina are partly resolved based on borehole geophysical logs and a recently documented geologic map and corehole. A conceptual model theorizes the depositional history of the sediments and geologically accounts for their distribution. Documented pumping tests of the Potomac aquifer at 197 locations produced 336 values of transmissivity and 127 values of storativity. Based on effective aquifer thicknesses, 296 values of sediment hydraulic conductivity and 113 values of sediment specific storage are calculated. Vertical hydraulic gradients are calculated from 9,479 pairs of water levels measured between November 17, 1953, and October 4, 2011, in 129 closely spaced pairs of wells. Borehole sediment-interval and related data provide a means to achieve high yielding production wells in the Potomac aquifer by site-specific targeting of drilling operations toward water-bearing coarse-grained sand and gravel. Advance knowledge of the potential of different parts of the aquifer also aids in planning optimal groundwater-development areas. Depositional subareas further provide a possible context for resource management. Current (2013) regulatory limits on water-level declines are relative to top surfaces of subdivided upper, middle, and lower Potomac aquifers across the entire Virginia Coastal Plain, but have the potential to exceed the same limit relative to a single undivided Potomac aquifer. By contrast, designation of the sediments as a single aquifer in the Norfolk arch and Albemarle embayment subareas—and as a series of vertically spaced subaquifers and intervening confining units in the Salisbury embayment subarea—best reflects understanding of the Potomac aquifer and can avoid the potential for excessive water-level declines. Simulation modeling to evaluate effects of groundwater withdrawals could be designed similarly, including vertical discretization and (or) zonation of the Potomac aquifer based on depositional subareas and a geostatistical distribution of aquifer properties derived from borehole sediment-interval data. Further resource-management information needs extend beyond the developed part of the Potomac aquifer, particularly across the Northern Neck and Middle Peninsula where only the shallowest part of the aquifer is known, and include structural aspects such as faults, basement bedrock, and the Chesapeake Bay impact crater.

Maryland, North Carolina, Virginia↗

USGS2015

Carbon dioxide storage in unconventional reservoirs workshop: summary of recommendations

“Unconventional reservoirs” for carbon dioxide (CO 2 ) storage—that is, geologic reservoirs in which changes to the rock trap CO 2 and therefore contribute to CO 2 storage—including coal, shale, basalt, and ultramafic rocks, were the focus of a U.S. Geological Survey (USGS) workshop held March 28 and 29, 2012, at the National Conservation Training Center in Shepherdstown, West Virginia. The goals of the workshop were to determine whether a detailed assessment of CO 2 storage capacity in unconventional reservoirs is warranted, and if so, to build a set of recommendations that could be used to develop a methodology to assess this storage capacity. Such an assessment would address only the technically available resource, independent of economic or policy factors. At the end of the workshop, participants agreed that sufficient knowledge exists to allow an assessment of the potential CO 2 storage resource in coals, organic-rich shales, and basalts. More work remains to be done before the storage resource in ultramafic rocks can be meaningfully assessed. In order to assess the CO 2 storage capacity of coals and organic-rich shales, the workshop participants agreed that the following several factors are key: sorption mechanisms and capacity, pore fluid composition and saturation, thermal maturity, formation thickness, and whether hydrocarbons have been extracted from the formation previously (for example, by enhanced gas or oil recovery). In order to assess the CO 2 storage capacity of basalts, the workshop participants agreed that key factors include temperature, pressure, pH, water chemistry, mineral chemistry, organic content, mineralogy, porosity, permeability, relative permeabilities, and CO 2 phase. The storage capacity for all unconventional reservoirs may be modeled using a volumetric equation starting with the extent of the rock unit and adjusted using these key factors and reaction terms. The ideas that were developed during this workshop can be used by USGS scientists to develop a methodology to assess the CO 2 storage resource in unconventional reservoirs. This methodology could then be released for public comment and peer review. After completing this development process, the USGS could then use the methodology to assess the CO 2 storage resource in unconventional reservoirs.

Open-File Report↗

USGS1982

Water-quality assessment of the Smith River drainage basin, California and Oregon

A water-quality assessment of the Smith River drainage basin was made to provide a summary of the water-quality conditions including known or potential water-quality problems. Results of the study showed that the water quality of the Smith River is excellent and generally meets the water-quality objectives for the beneficial uses identified by the California Regional Water Quality Control Board, North Coast Region. Known and potential problems related to water quality include: Sedimentation resulting from both natural erosional processes and land-use activities such as timber harvest, road construction, and mining that accelerate the erosional processes; bacterial contamination of surface and ground waters from inundated septic tanks and drainfields, and grazing activities; industrial spills which have resulted in fish kills and oil residues; high concentrations of iron in ground water; log and debris jams creating fish migration barriers; and pesticide and trace-element contamination from timber-harvest and mining activities, respectively. Future studies are needed to establish: (1) a sustained long-term monitoring program to provide a broad coverage of water-quality conditions in order to define long-term water-quality trends; and (2) interpretive studies to determine the source of known and potential water-quality problems.

California, Oregon↗