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At least 1,153 records · Page 64Linked to original sources
USGS2014

Review and bibliometric analysis of published literature citing data produced by the Gap Analysis Program (GAP)

The Gap Analysis Program (GAP) of the U.S. Geological Survey (USGS) produces geospatial datasets providing information on land cover, predicted species distributions, stewardship (ownership and conservation status), and an analysis dataset which synthesizes the other three datasets. The intent in providing these datasets is to support the conservation of biodiversity. The datasets are made available at no cost. The initial datasets were created at the state level. More recent datasets have been assembled at regional and national levels. GAP entered an agreement with the Policy Analysis and Science Assistance branch of the USGS to conduct an evaluation to describe the effect that using GAP data has on those who utilize the datasets (GAP users). The evaluation project included multiple components: a discussion regarding use of GAP data conducted with participants at a GAP conference, a literature review of publications that cited use of GAP data, and a survey of GAP users. The findings of the published literature search were used to identify topics to include on the survey. This report summarizes the literature search, the characteristics of the resulting set of publications, the emergent themes from statements made regarding GAP data, and a bibliometric analysis of the publications. We cannot claim that this list includes all publications that have used GAP data. Given the time lapse that is common in the publishing process, more recent datasets may be cited less frequently in this list of publications. Reports or products that used GAP data may be produced but never published in print or released online. In that case, our search strategies would not have located those reports. Authors may have used GAP data but failed to cite it in such a way that the search strategies we used would have located those publications. These are common issues when using a literature search as part of an evaluation project. Although the final list of publications we identified is not comprehensive, this set of publications can be considered a sufficient sample of those citing GAP data and suitable for the descriptive analyses we conducted.

Open-File Report↗
USGS2014

Investigations into near-real-time surveying for geophysical data collection using an autonomous ground vehicle

The U.S. Geological Survey and the National Aeronautics and Space Administration are cooperatively investigating the utility of unmanned vehicles for near-real-time autonomous surveys of geophysical data collection. Initially focused on unmanned ground vehicle collection of magnetic data, this cooperative effort has brought unmanned surveying, precision guidance, near-real-time communication, on-the-fly data processing, and near-real-time data interpretation into the realm of ground geophysical surveying, all of which offer advantages over current methods of manned collection of ground magnetic data. An unmanned ground vehicle mission has demonstrated that these vehicles can successfully complete missions to collect geophysical data, and add advantages in data collection, processing, and interpretation. We view the current experiment as an initial phase in further unmanned vehicle data-collection missions, including aerial surveying.

California↗
USGS2015

An evaluation of the accuracy of modeled and computed streamflow time-series data for the Ohio River at Hannibal Lock and Dam and at a location upstream from Sardis, Ohio

Between July 2013 and June 2014, the U.S. Geological Survey (USGS) made 10 streamflow measurements on the Ohio River about 1.5 miles (mi) downstream from the Hannibal Lock and Dam (near Hannibal, Ohio) and 11 streamflow measurements near the USGS Sardis gage (station number 03114306) located approximately 2.4 mi upstream from Sardis, Ohio. The measurement results were used to assess the accuracy of modeled or computed instantaneous streamflow time series created and supplied by the USGS, U.S. Army Corps of Engineers (USACE), and National Weather Service (NWS) for the Ohio River at Hannibal Lock and Dam and (or) at the USGS streamgage. Hydraulic or hydrologic models were used to create the modeled time series; index-velocity methods or gate-opening ratings coupled with hydropower operation data were used to create the computed time series. The time step of the various instantaneous streamflow time series ranged from 15 minutes to 24 hours (once-daily values at 12:00 Coordinated Universal Time [UTC]). The 15-minute time-series data, computed by the USGS for the Sardis gage, also were downsampled to 1-hour and 24-hour time steps to permit more direct comparisons with other streamflow time series. To facilitate comparisons between measurement results and time-series data, streamflows corresponding to the times of the streamflow measurements were computed from the time-series data by time-based linear interpolation. Prior to doing interpolations, measurement times for the Hannibal Lock and Dam location were adjusted for traveltime to account for the fact that the streamflow measurements were made about 1.5 mi downstream from the location corresponding to the modeled/computed time-series data. Measured and interpolated streamflows were tabulated along with residuals (the difference between measured and interpolated streamflows) and selected summary statistics. Overall, streamflows interpolated from the USGS computed 15-minute time-series data (hereafter referred to as the USGS 15-minute time-series data) had the smallest root-mean-square error (RMSE) (3,939 cubic feet per second [ft 3 /s]) and the second smallest mean absolute residual (2,636 ft 3 /s), whereas streamflows interpolated from the USACE 12 UTC time series had the largest RMSE (14,590 ft 3 /s) and the largest mean absolute residual (10,800 ft 3 /s). The larger RMSEs for streamflows interpolated from the USACE 12 UTC time series likely resulted in part from the coarser time step of that time series. Streamflows interpolated from the USGS downsampled 1-hour time series had the second smallest RMSE (4,025 ft 3 /s) and the smallest mean absolute residual (2,600 ft 3 /s). Somewhat surprisingly, streamflows interpolated from the NWS 6-hour model time series had the third smallest RMSE (4,483 ft 3 /s) and mean absolute residual (4,050 ft 3 /s) in spite of being determined from a time series with a coarser time step than the USACE 1-hour modeled and computed time series. Measured streamflows at the Sardis gage and at the Hannibal Lock and Dam measurement location were plotted versus residuals (expressed as a percentage of the measured streamflows) of corresponding interpolated time-series streamflow values. Results for each of the time series exhibited some anomaly, possibly indicating the need and (or) potential for improvement in the streamflow computational/modeling processes. Streamflow hydrographs were plotted for modeled/computed time series for the Ohio River near the USGS Sardis gage and the Ohio River at the Hannibal Lock and Dam. In general, the time series at these two locations compared well. Some notable differences include the exclusive presence of short periods of negative streamflows in the USGS 15-minute time-series data for the gage on the Ohio River above Sardis, Ohio, and the occurrence of several peak streamflows in the USACE gate/hydropower time series for the Hannibal Lock and Dam that were appreciably larger than corresponding peaks in the other time series, including those modeled/computed for the downstream Sardis gage

Ohio↗
USGS2021

U.S. Geological Survey Great Lakes Science Forum—Summary of remaining data and science needs and next steps

A U.S. Geological Survey-led assessment of data gaps and science needs across the Great Lakes ecosystem indicated the following: • Expanded data collection or monitoring would provide basic ecosystem, social, and public health data to manage the Great Lakes system and to develop and test models and decision support tools. • New science and advanced technologies (for example, sensors and high-performance computing capability) would improve the understanding of critical threats, such as harmful algae blooms and high-water levels. Although there is significant scientific knowledge in specific areas or for specific topics, managers could use improved models and decision support tools, strengthened by extensive data collection and developed at multiple scales, to better inform decision making in the future. Enhanced coordination of agency efforts and associated data collection across data types (for example, prey fish populations and water levels) is needed to effectively manage the Great Lakes. This report highlights the data gaps; benefits of better, more structured coordination; and areas of concern specifically related to data collection/measurement and science efforts. It summarizes and analyzes stakeholder feedback and information from review of scientific literature. Finally, the report outlines steps necessary to create an integrated Great Lakes science plan.

Open-File Report↗
USGS2024

Assessment of water levels, nitrate, and arsenic in the Carson Valley Alluvial Aquifer and the development of a data visualization tool for the Carson River Basin, Nevada

Residents of Carson Valley, Douglas County, Nevada, rely on the basin-fill alluvial aquifer underlying the valley for drinking water. Since the 1980s, groundwater levels and water-quality data have been collected to monitor the status of the aquifer system and to assist in planning efforts to address current (2024) and future demand. The U.S. Geological Survey (USGS), in cooperation with Douglas County, Nevada, evaluated trends in water levels, nitrate, and arsenic concentrations from a network of monitoring and domestic wells in Carson Valley. This work also assessed the monitoring well network to determine the suitability of wells for characterizing the occurrence of arsenic in the groundwater. Monitoring of constituents, such as nitrate and arsenic concentrations, is needed to assess changes in contaminant distribution and to evaluate the effect that changing land use and groundwater pumping has on their occurrence and transport. Results of the trend analysis indicate water levels are declining ( p <0.05) in 17 of 26 selected monitoring wells (65 percent). Areas with the largest change in water levels, with more than 20 feet of declines, were within the community areas of Johnson Lane, Ruhenstroth, South Agricultural, East Valley, and Fish Springs. Variations in water levels measured in wells from the Central Agricultural, Minden, Foothill, Alpine County (one well), and Gardnerville Ranchos areas show periods of increase and decrease over time, but they also maintain long-term declining trends ( p <0.05). Increases in nitrate concentrations in groundwater samples collected from 9 out of 14 selected monitoring wells (64 percent) are statistically significant ( p <0.05) within the Ruhenstroth, Gardnerville Ranchos, East Valley, Genoa, and Johnson Lane community areas. Samples collected from a well in Indian Hills/Jacks Valley indicated a decreasing trend in nitrate concentration over time. Nitrate concentrations in samples collected from wells in East Valley, Genoa, Johnson Lane, and Indian Hills/Jack Valley were consistently low (less than 3 milligrams per liter [mg/L]) and stable. Nitrate concentrations from selected wells in Johnson Lane and Garnerville Ranchos exceeded the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10 mg/L (as nitrogen) and have trends that are increasing over time. In 2022, a sample collected from Johnson Lane had a concentration (7.3 mg/L) below the MCL with an increasing trend over time. Temporal trend analyses for groundwater arsenic concentrations in Carson Valley could not be done because of a lack of temporal data. However, using available historical data, arsenic concentrations seem to be greater in groundwater from wells located on the eastern and northern areas of the valley than in wells located on the western or southern areas. Groundwater arsenic concentrations exceed 5 micrograms per liter (μg/L) in most samples collected from wells in Johnson Lane, Airport, Central Agricultural, and East Valley areas and in many cases exceed the U.S. Environmental Protection Agency (EPA) MCL of 10 μg/L. Data indicate that groundwater from domestic wells screened at deeper intervals are likely more vulnerable to elevated arsenic concentrations than shallower wells. A groundwater network evaluation for Carson Valley identified potential modifications in the sampling locations and frequency to better understand the effect of groundwater pumping in communities where municipal and domestic demand are greatest, potentially enhancing understanding of contaminant transport in these areas. Potential modifications to the active well network include reducing the frequency of sample collection from existing network wells (6 out of 11) that have consistently shown low and stable nitrate concentrations, adding wells in areas where data are sparse, and increasing the number of wells in areas with elevated groundwater nitrate concentrations. Including the analysis of arsenic in samples from the active groundwater monitoring well network will provide more detail on the temporal and spatial variability of arsenic concentrations. A visualization tool for the Carson River Basin was developed to provide access to discrete and near real-time hydrologic and water-quality data. The Carson River Basin Hydro Mapper (CBH; U.S. Geological Survey, 2023b) shows active and historical discrete water levels measured by the USGS and the State of Nevada Division of Water Resources, discrete groundwater nitrate and arsenic concentration data collected by the USGS, near real-time streamflow, and surface water levels for select waterbodies. The hydrologic data in the CBH provides resource managers, the public, and the scientific community with an easily accessible tool to present and communicate the most up-to-date information available about local and basin-wide water resources.

Nevada↗
USGS2024

U.S. Geological Survey Mississippi River Science Forum—Summary of data and science needs and next steps

The U.S. Geological Survey hosted a Mississippi River Science Forum with Federal agencies; Tribal, State, and local governments located in States that border the Mississippi River; academia; and other interested stakeholders. The purpose of the forum was to share current (2023) science; identify data gaps and areas of concern; and to prioritize next steps needed to advance the goals of improving water quality, restoring habitat and natural systems, improving navigation, eliminating aquatic invasive species, and building local resilience to natural disasters along the Mississippi River. The forum was a directive for the U.S. Geological Survey in the Consolidated Appropriations Act of 2022 (Public Law 117—103, 136 Stat. 49). Participants and stakeholders that attended the Mississippi River Science Forum indicated the following. A Mississippi River Science Committee could bring together the voices of all stakeholders, including Federal agencies; State, local, and Tribal governments; academia; nongovernmental organizations; business and industry; and other interested parties. This committee would also work with (but not replace) Mississippi River Basin entities already in place and establish effective communication to identify and address Basin-wide management needs and to develop holistic solutions for those needs. A Mississippi River science plan could expand on the science and data gaps identified by the Forum. This plan could guide data collection and help resource managers develop and implement restoration initiatives within the Basin, recognizing that addressing these needs will require substantial resources. The science committee, working with other entities in the basin, should develop data standards for the Mississippi River Basin that allow stakeholders to utilize comparable data to address their needs. These standards would include data findability, accessibility, interoperability, and reusability. This report highlights data gaps and areas of concern discussed during the forum, and it identifies needs to advance the goals of improving water quality, restoring habitat and natural systems, improving navigation, eliminating aquatic invasive species, and building local resilience to natural disasters with specific emphasis on data collection and measurement, and scientific investigation. The report also summarizes stakeholder input and feedback and outlines next steps identified by forum participants.

Open-File Report↗
USGS2025

Select elements of concern in surface water of three hydrologic basins (Delaware River, Illinois River, and Upper Colorado River)—Data screening for the development of spatial and temporal models

The report focuses on the screening of previously published concentration data associated with 12 elements of concern (aluminum, arsenic, cadmium, chromium, copper, iron, mercury, manganese, lead, selenium, uranium, and zinc) measured in stream surface waters of three hydrologic basins (Delaware River Basin, Illinois River Basin, and the Upper Colorado River Basin). The purpose of this analysis is to determine what subsets of the original dataset (containing more than 1,500,000 observations) may be most suitable for each of two types of modeling efforts. The first type of modeling envisions a machine learning approach to determine which geospatial attributes are most significant in describing the spatial distribution of elemental concentrations within a basin. The second type of modeling envisions a stepwise regression approach to develop multivariable models that can be used to determine high resolution time-series estimates of elemental concentrations or loads at discrete U.S. Geological Survey real-time stream surface water sites. These site-specific temporal models are based on continuous measurements of available discharge and (or) in situ sensor data (temperature, pH, turbidity, dissolved oxygen, specific conductance, and (or) fluorescent dissolved organic matter) as the explanatory variables. The data screening for both model types considered historical trends in analytical methods and detection quantitation limits, the extent of censored data, data density, and environmental relevance with respect to three U.S. Environmental Protection Agency water quality thresholds (drinking water guidelines, human health criteria, and aquatic life criteria). The result of this analysis was the production of a final list of potential models deemed suitable for further development based upon the data exclusion (or inclusion) scheme developed herein for each model type. In both cases, the final models included mostly the three crustal elements (iron, manganese, and aluminum) that are found at comparatively high concentrations in surface water, whereas most of the more pernicious elements were excluded from the final model lists owing to various data limitations. The one exception to this was arsenic, for which the existing data were sufficient at three U.S. Geological Survey real-time sites for potential further development of time-series models.

Colorado, Delaware, Illinois, Indiana, Maryland, N↗
USGS1960

Ground-water data for Fairbanks area, Alaska

A compilation of records of about 450 wells in the Fairbanks area is presented herein. The data were collected by D. J. Cedarstrom and Troy L. Pewe during the first phases of an investigation by the United States Geological Survey of the permafrost, terrain, and water resources of the Fairbanks area. The enclosed map of the area, showing well locations, was prepared by the Regional Sanitary Engineer, Sanitation and Engineering, Alaska Department of Health and Welfare. The data were released to the Survey's open file in 1948, but are reproduced in the Alaska Department of Health and Welfare Hydrological Data series to insure preservation. Where known, the data include for each well the names of the owner and driller; the depth of the well; the depth to the top and bottom of permafrost; and the reported quality of water. The well records and location may be very useful for future subsurface investigations or construction. The well location map was based on the Fairbanks street names as of 1948. Since that time, many of the street names and the numbering system have changed. Hence, the reader should not refer to the address of a particular well, but to the well number when locating a well on the map. The Geological Survey has recompiled the well data in the Fairbanks area for its final phase of a ground-water study. Data through 1954 is to be presented in a Water-Supply Paper now in preparation. Pertinent portions of the enclosed well data will be presented in the forthcoming report. Some of the enclosed well data, and additional well logs, have been published in a report (Pewe, Troy L., 1958, Geology of the Fairbanks (D-2) quadrangle, Alaska: U. S. Geological Survey GQ 110) describing the geology and subsurface conditions in the area.

Alaska↗
USGS1950

Ground-water data collected in the Missouri River basin units in Kansas during 1949

Ground-water studies in the Missouri River Basin were begun by the United States Geological Survey during the fall of 1945 as a part of the program for development of the resources of the basin by the U.S. Bureau of Reclamation and other Federal Agencies. The studies of the ground-water resources in the part of Kansas that lies within the Basin have been coordinated with the cooperative program of ground-water studies already being carried on in Kansas by the Federal Geological Survey and the State Geological Survey of Kansas with the cooperation of the Division of Sanitation of the Kansas State Board of Health and the Division of Water Resources of the Kansas State Board of Agriculture. Areas in which ground-water data have been collected under the Missouri Basin program include the Almena Unit in Norton and Phillips Counties; the Bostwick Unit in Jewell, Republic, and Cloud Counties; the Cedar Bluff Unit in Ellis, Rush, and Trego Counties; the Glen Elder Unit in Mitchell County; the Webster Unit in Osborne County; and the Wilson Unit in Lincoln County. Most of the ground-water data presented in this report were collected during 1949. Most of the data collected in these areas prior to the end of 1947 were presented in a report that was mimeographed in September 1948 and most of the data collected during 1948 were presented in a report that was mimeographed in November 1949. This report is the third of a series of annual reports on ground-water data collected in the Missouri Basin units in Kansas. These annual reports are a means of more promptly releasing for administrative use the data collected each year. Data that are included in the annual reports for a given area will be assembled later in a report on the geology and hydrology of that area. An index of the data collected and presented in the 1947, 1948, and 1949 reports is given in table 1.

Kansas↗
USGS1970

A proposed streamflow-data program for Wisconsin

An evaluation of the streamflow data available in Wisconsin was made to provide guidelines for planning future programs. The basic steps in the evaluation procedure were (1) definition of the long-term goals of the streamflow data program, (2) examination and analysis of all available data to determine which goals have already been met, and (3) consideration of alternate programs and techniques to meet the remaining objectives. A streamflow data program based on these guidelines is proposed for the future. Streamflow data collected at gaging stations were classified according to the type of use or purpose. Recommendations were made as to whether a station should be included in the proposed network or whether it had met the objective for which it was operated and could be discontinued. The historical data acquired and the new data to be collected form the basis for analytical and interpretive reports. Recommendations were made as to expanding or initiating such studies. Streamflow data collection should be a continuing effort, reoriented as necessary to meet the changing needs.

Open-File Report↗
USGS1975

Data summary of June-July 1975 floods in eastern North Dakota and northwestern Minnesota

Torrential rains during late June and early July 1975, combined with wet antecedent conditions, caused severe flooding, mainly along the lower reaches of the Sheyenne and Maple Rivers and their tributaries in North Dakota, and in the Buffalo and Wild Rice River basins in Minnesota. The Red River of the North from the Fargo-Moorhead area to the Halstad, Minnesota area was also severely flooded. Because much of the region is extremely flat, large areas of the two States were inundated by flood waters. Damage, mostly agricultural, was widespread and damage estimates exceeded a quarter of a billion dollars. Local, State, and Federal officials need factual information to evaluate, coordinate, and manage programs concerned with flood losses. The purpose of this report is to provide quickly a summary of some of the basic data collected on the June-July 1975 floods. Only a part of the information collected by the U.S. Geological Survey on the extent and magnitude of the floods is presented. This information includes the magnitude and frequency of the instantaneous maximum stages (water-surface elevations) and flow rates for 62 sites, measured sediment loads at 7 sites, and hydrographs of daily mean flow at 6 sites. Additional streamflow information associated with the floods will be provided subsequently in annual data releases of the Geological Survey. The report also describes availability of graphic or photographic data depicting the areal extent of inundation. Those data may be obtained from the Applications Assistance Branch, EROS Data Center, U.S. Geological Survey, Sioux Falls, S. Dak. 57198. Only a minimal amount of rainfall data are summarized in this report to aid in documenting the flood event. These data were provided by the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce, and by the Minnesota State Office of Climatology. This assistance in providing the data and in reviewing the form of its presentation is appreciated.

Minnesota, North Dakota↗
USGS1982

Hydrologic data from monitoring of saline-water intrusion in the Cape Coral area, Lee County, Florida

As a result of declining water levels and saline-water intrusion in the Cape Coral area, the U.S. Geological Survey in cooperation with the City of Cape Coral established a monitoring well network in Cape Coral and adjacent areas in 1978-79. The network was designed to provide indication of lateral movement of saline water in the upper part of the Hawthorn Formation; to provide trends in water levels; and to provide background data from: (1) the aquifer in the upper part of the Hawthorn Formation; (2) the aquifer in the lower part of the Hawthorn Formation and upper part of the Tampa Limestone; and (3) the surficial aquifer. The monitoring well network consists of 77 wells. Data collected in this network since 1978, as well as data collected from selected wells in the network prior to 1978, are compiled in this report. These data include water-quality data from 69 wells, water-level data from 29 wells, and lithologic logs from 18 wells. Other data compiled in this report include municipal pumpage and rainfall data supplied by the City of Cape Coral.

Florida↗
USGS1983

Alternate data sources for soil surveys on rangeland

Soil information is an essential theme in a digital information base for land management and resource monitoring, but public land management agencies seldom have detailed soil maps available for all of the area under their administration. Most of these agencies conduct soil surveys on a scheduled basis, but escalating costs and declining budgets are reducing the number of surveys that can be scheduled. Digital elevation and satellite spectral data are available or are obtainable for all areas in the continental United States and may be used as an aid to produce soils data. A study was conducted in the Grass Creek Resource Area in north-central Wyoming to assess the utility of incorporating digital elevation and Landsat data into an information base for soil survey and to evaluate the usefulness of these data as an input to an order-three soil survey. Slope-interval maps were produced from digital elevation data and topographic maps of three 7.5-minute quadrangle areas. These slope-interval maps were then overlaid on orthophotoquadrangles and used to produce photo-interpreted physiographic maps. These physiographic maps were digitized into a data base and used with Landsat multispectral scanner data to produce tabular summaries that describe each map polygon in terms of physiographic unit, slope, aspect, elevation, area, and spectral values. A good relationship was found between the physiographic units and soil mapping units defined during a conventional soil survey, and between the Landsat spectral categories and existing vegetation communities. Field evaluations confirmed the feasibility of using this approach for producing physiographic maps as an aid for mapping soils and range sites. The project is a cooperative investigation of the Earth Resources Observation Systems Data Center of the U.S. Geological Survey, the Soil Conservation Service, and the Bureau of Land Management.

Open-File Report↗
USGS1984

Hydrologic data for the Larimer-Weld regional water-monitoring program, Colorado, 1975-82

The Larimer-Weld, Colorado, regional Monitoring Program was begun in 1976 to provide information on the quality and quantity of the surface-water resources in the area. Three stations on the big Thompson River and five stations on the Cache La Poudre River were selected for a data-collection network. Four previously established stations were added to complete the data-collection network: Horsetooth Reservoir, Joe Wright Creek above and below Joe Wright Reservoir, and Michigan River near Cameron Pass. Station description, location, and period of record are given for each station. A statistical summary of the water-quality data for each station is tabulated. Frequency of occurrence is given at the 95th, 75th, 50th, and 25th percentiles. Monthly water-quality data and daily average streamflow data are tabulated for each streamflow station for which this data was collected; Monthly contents data are presented for Horsetooth Reservoir. All data tabulated and summarized are from the period October 1, 1975, through September 30, 1982. (USGS)

Open-File Report↗
USGS1985

Selected test-well data from the MX-missile siting study, Tooele, Juab, Millard, Beaver, and Iron Counties, Utah

This report contains well data collected from 1979 to 1983 in a part of the Great Basin in western Utah (fig. 1). The area is characterized by a series of generally north-trending mountain ranges separated by alluviumfilled basins that are partially filled with sedimentary deposits eroded from the adjacent mountains and lacustrine sediments deposited by Lake Bonneville. Most of the intermountain basins are elongated in the northward direction, but some are almost equidimensional. This report was prepared as part of the Great Basin Regional AquiferSystem Analysis (RASA) program. The report is intended to make well data from the MX-missile siting study readily available to water-resource managers and the general public. It includes well data obtained in areas for which little or no such data have been published previously. Well-drilling and well-completion data were compiled by Ertec, Inc. (formerly Fugro National, Inc.) under contract with the U. S. Air Force. Those data along with aquifer test data, geophysical logs, and drillers1 or geologists1 logs were obtained from Ertec, Inc. under an agreement with the U.S. Air Force. The authors thank the officials of both Ertec, Inc. and the U.S. Air Force for their helpful cooperation. The U.S. Geological Survey obtained accurate locations of the test wells (pi. 1) and accurate water-level measurements in those wells (table 1). Chemical analyses of water samples collected from several of the test wells drilled in the Sevier Desert have been published in a report by Enright and Holmes (1982, table 5). Test drilling for the MX-missile siting study consisted of two parts, the verification phase and the water-resources phase. The verification jhase was designed to obtain information necessary for the design and construction of the MX-basing system. Numerous small diameter wells were bored with depths ranging from 92 to 205 feet. Two-inch diameter JVC casing with the bottom 20 feet perforated was installed in each borehole. The water-resources phase was designed to determine ground-water availibility and to estimate the effects of ground-water withdrawals required for the construction of the MX-basing system. Six large-diameter production test wells were drilled along with associated small-diameter observation wells. Depths ranged from 310 to 1,399 feet. Lithologic logs for selected production test wells or associated observation wells are listed in table 2. Geophysical logs and aquifer test data are available in the files of the U. S. Geological Survey, as indicated in table 1.

Utah↗
USGS1986

Hydrologic data for the south-central area, Nebraska

Hydrologic data were compiled for the South-Central hydrogeology study, which covers an area of approximately 5,600 square miles in south-central Nebraska. Data pertain to the groundwater, surface water, climate, land use, and pumpage and precipitation at water use sites in the study area. Groundwater data include water level elevations from three mass measurements of wells and water quality information from 68 water quality sampling sites. Surface water data include average annual stream flows and average October through December streamflows at U.S. Geological Survey gaging stations, canal diversions, and seepage from canals and reservoirs. Climatic data include monthly precipitation records for eight weather stations and evaporation data from four reservoirs. Land use data were compiled for agricultural land uses, by county, from 1940 through 1981. Water use site data include water levels at each of 18 sites, soil information for those sites with complete precipitation and pumpage records, and precipitation and groundwater pumpage information for each site. (USGS)

Open-File Report↗
USGS1988

Hydrologic data for urban studies in the Austin metropolitan area, Texas, 1986

The Geological Survey, in cooperation with the Texas Department of Water resources, began hydrologic studies in the Austin urban area in 1954. In cooperation with the city of Austin, the program was expanded in 1975 to include additional streamflow and rainfall-gaging stations, and the collection of surface water-quality data. In 1978, the program was expanded to include a ground-water resources study of the South Austin metropolitan area in the Balcones fault zone. The objectives of the Austin urban hydrology study are as follows: To determine, on the basis of historical data and hydrologic analyses, the magnitude and frequency of flood peaks and flood volume. To determine the effect of urban development on flood peaks and volume. To determine the variations in water quality during different seasons and flow conditions in representative watersheds with various types of urban development. To quantitatively appraise the ground-water resources of the Edwards aquifer in hydraulic circulation with Barton Springs, the effect of urbanization on the quality and quantity of recharge and discharge, and the extent of contamination in the aquifer. This report presents the basic hydrologic data collected in the Austin urban area for the 1986 water year (Oct. 1, 1985 to Sept. 30, 1986). Additional explanations of terms related to streamflow, water quality, and other hydrologic data used in this report are defined in the U.S. Geological Survey annual report Water Resources Data for Texas, TX-85-3, 1986. Analyses of "Hydrologic data for urban studies in the Austin, Texas, metropolitan area" from 1975 to 1982 are presented in a report by Veenhuis and Gannett (1986). Two analyses were made to determine the effects of urbanization on flood peaks in streams in the Austin metropolitan area. The first analysis compares flood recurrence intervals of urban drainage basins to rural drainage basins. In the second analysis, data from one drainage basin in which considerable urban development occurred during the study period, were used. The data were analyzed for changes in rainfall-runoff and flood frequency relations due to urbanization.

Open-File Report↗
USGS1989

A general method for generating bathymetric data for hydrodynamic computer models

To generate water depth data from randomly distributed bathymetric data for numerical hydrodymamic models, raw input data from field surveys, water depth data digitized from nautical charts, or a combination of the two are sorted to given an ordered data set on which a search algorithm is used to isolate data for interpolation. Water depths at locations required by hydrodynamic models are interpolated from the bathymetric data base using linear or cubic shape functions used in the finite-element method. The bathymetric database organization and preprocessing, the search algorithm used in finding the bounding points for interpolation, the mathematics of the interpolation formulae, and the features of the automatic generation of water depths at hydrodynamic model grid points are included in the analysis. This report includes documentation of two computer programs which are used to: (1) organize the input bathymetric data; and (2) to interpolate depths for hydrodynamic models. An example of computer program operation is drawn from a realistic application to the San Francisco Bay estuarine system. (Author 's abstract)

Open-File Report↗