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At least 1,081 records · Page 60Linked to original sources
USGS2025

Climate change impacts on plant communities in the sagebrush region—A science synthesis to inform Bureau of Land Management resource management

This report synthesizes current (2024) science-based knowledge related to the impacts of climate change on big sagebrush vegetation in Western North America. This effort was conducted through the U.S. Geological Survey working with the Bureau of Land Management as part of multiple science syntheses to aid management agencies developing environmental impacts assessments in response to human-related or caused events. This report reviews the potential impacts climate change may have on sagebrush vegetation and related management decisions. The body of the synthesis introduces the diverse impacts of climate change across the region by first focusing directly on what climate change may entail in terms of altered temperature and precipitation patterns. The report then discusses how these changes could likely affect individual plant species based on experimental results and scale the impacts to species distributions and community composition. The synthesis section ends by surveying efforts to model potential future changes in habitat. The report goes on to link the synthesis conclusions to individual land uses or land management decisions, such as forage resources, restoration or fuel treatment. Finally, the report provides a section that discusses the pros and cons of available datasets that model the potential future of vegetation in the sagebrush region.

Arizona, California, Colorado, Idaho, Montana, Nev↗
USGS1959

Lithologic log and drilling information for the Marble exploration hole 3, U15 area, Nevada Test Site, Nye County, Nevada

The Marble exploration hole 3 is in the northern part of the Tippipah Spring NE 7-1/2 minute quadrangle at the north end of Yucca Valley (fig.1). The collar elevation of the hole is about 5,316 feet and has the approximate Nevada State coordinates of N. 903,093 and E. 674,870. The hole was drilled to determine the physical and chemical properties of the marble within a radius of 200 feet of a point 950 feet below the surface. The exploration hole is 978 feet deep and was drilled from June 12 to July 8, 1959, by Minerals Engineering Co. of Grand Junction, Colorado, using conventional NX coring equiipment and a Portadrill 2,500 drill rig. Water-base bentonitic mud was used as the drilling fluid in the upper part of the hole. Clear water was used after circulation became unrestorable below 200 feet. The hole was cased from surface to 20 feet. The drilling rate during coring ranged from 2.0 to 19.3 minutes per foot and averaged 4.6 minutes per foot (table 1). The core recovered was excellent in quality and quantity. The average core recovery is 92.7 percent (table 2).

Nevada↗
USGS2024

Semi-automated methods to develop a unified geographic information system dataset

Geospatial data describing the topography, natural features, human-built features, and land uses of a particular area or region can come from independent data providers and, therefore, vary in format, data encoding, and geographic coverage. Because of the complexity of the processes and procedures required for unifying these heterogeneous data into a dataset with consistent format, encoding, and coverage, fully automated procedures for data unification do not exist. However, a combination of manual and automated procedures—semi-automated methods—can substantially reduce the time required for data unification while improving accuracy. This report presents three semi-automated data-unification methods in detail. Although these methods are not new in principle, their details are the result of original development work, and they serve as examples that can be reused, adapted, or generalized to provide head starts to future data-unification projects. The format of this report can be used and refined to encourage the publication of future reports and more widespread sharing of semi-automated methods.

Techniques and Methods↗
USGS2009

Estimating Prediction Uncertainty from Geographical Information System Raster Processing: A User's Manual for the Raster Error Propagation Tool (REPTool)

The U.S. Geological Survey Raster Error Propagation Tool (REPTool) is a custom tool for use with the Environmental System Research Institute (ESRI) ArcGIS Desktop application to estimate error propagation and prediction uncertainty in raster processing operations and geospatial modeling. REPTool is designed to introduce concepts of error and uncertainty in geospatial data and modeling and provide users of ArcGIS Desktop a geoprocessing tool and methodology to consider how error affects geospatial model output. Similar to other geoprocessing tools available in ArcGIS Desktop, REPTool can be run from a dialog window, from the ArcMap command line, or from a Python script. REPTool consists of public-domain, Python-based packages that implement Latin Hypercube Sampling within a probabilistic framework to track error propagation in geospatial models and quantitatively estimate the uncertainty of the model output. Users may specify error for each input raster or model coefficient represented in the geospatial model. The error for the input rasters may be specified as either spatially invariant or spatially variable across the spatial domain. Users may specify model output as a distribution of uncertainty for each raster cell. REPTool uses the Relative Variance Contribution method to quantify the relative error contribution from the two primary components in the geospatial model - errors in the model input data and coefficients of the model variables. REPTool is appropriate for many types of geospatial processing operations, modeling applications, and related research questions, including applications that consider spatially invariant or spatially variable error in geospatial data.

Techniques and Methods↗
USGS2002

Standards for the Analysis and Processing of Surface-Water Data and Information Using Electronic Methods

Surface-water computation methods and procedures are described in this report to provide standards from which a completely automated electronic processing system can be developed. To the greatest extent possible, the traditional U. S. Geological Survey (USGS) methodology and standards for streamflow data collection and analysis have been incorporated into these standards. Although USGS methodology and standards are the basis for this report, the report is applicable to other organizations doing similar work. The proposed electronic processing system allows field measurement data, including data stored on automatic field recording devices and data recorded by the field hydrographer (a person who collects streamflow and other surface-water data) in electronic field notebooks, to be input easily and automatically. A user of the electronic processing system easily can monitor the incoming data and verify and edit the data, if necessary. Input of the computational procedures, rating curves, shift requirements, and other special methods are interactive processes between the user and the electronic processing system, with much of this processing being automatic. Special computation procedures are provided for complex stations such as velocity-index, slope, control structures, and unsteady-flow models, such as the Branch-Network Dynamic Flow Model (BRANCH). Navigation paths are designed to lead the user through the computational steps for each type of gaging station (stage-only, stagedischarge, velocity-index, slope, rate-of-change in stage, reservoir, tide, structure, and hydraulic model stations). The proposed electronic processing system emphasizes the use of interactive graphics to provide good visual tools for unit values editing, rating curve and shift analysis, hydrograph comparisons, data-estimation procedures, data review, and other needs. Documentation, review, finalization, and publication of records are provided for with the electronic processing system, as well as archiving, quality assurance, and quality control.

Water-Resources Investigations Report↗
USGS1995

Water-quality assessment of the White River Basin, Indiana: Analysis of available information on pesticides, 1972-92

An analysis of historical pesticide data (1972-92) for the White River was conducted as part of the U.S. Geological Survey National Water-Quality Assessment Program. Data on the presence of pesticides in streams, bottom sediments, fish, and ground waters were examined. Results are interpreted with respect to spatial, seasonal, and streamflow effects. Concentrations of water-soluble pesticides reach a peak during the first storm following application and remain elevated for 1 to 2 months. The most herbicide loading to the White River occurs during this time, when about 1 percent of the applied herbicides are transported out of the White River Basin. Bottom sediments and fish were analyzed for lipophilic pesticides. Dieldrin, components of technical chlordane, and DDT-related compounds were the most frequently detected. In areas where pesticide concentrations in sediment were high, concentrations in fish were high, indicating that bottom sediments are probably the primary source of lipophilic pesticides in aquatic biota. Ground- water/surface-water interaction and the presence of pesticides in ground waters were examined. The bedrock karst region had the highest degree of ground-water/surface-water interaction, indicating that the shallow ground water is susceptible to contamination from surface sources. Atrazine was the most frequently detected pesticides in ground waters. All wells where pesticides were detected are in karst or alluvial outwash, indicating that these geomorphic units are highly susceptible to contamination.

Indiana↗
USGS1995

Water-quality assessment of the Trinity River Basin, Texas - Review and analysis of available pesticide information, 1968-91

In 1991 the Trinity River Basin study unit was among the first 20 study units in which work began under full-scale program implementation of the National Water-Quality Assessment Program. A retrospective assessment was undertaken to review and analyze existing pesticide data and related environmental factors. Population and land-use data indicate human modifications to the landscape and hydrologic system of the study area during the period 1968–91. A variety of crops treated with pesticides were identified, with wheat and cotton accounting for the largest number of acres treated annually (541,250 and 519,870 acres, respectively). Agricultural-use estimates for the later period covered by this report (1988–90) indicate that 105 different pesticides were used and that 24 pesticides accounted for 75 percent of average agricultural use in the study area. Sorghum was treated by the largest number of the 24 mostused pesticides, and cotton was treated by the second largest number of those pesticides. Dimethoate and methyl parathion were the most heavily used of the organophosphate class pesticides. The herbicide 2,4–D was the most heavily used chlorophenoxy pesticide. Carbamate pesticides are used extensively in the study area, with carbaryl, carbofuran, methomyl, and thiodicarb accounting for the majority of the use of this class of pesticide. Miscellaneous pesticides included alachlor, arsenic acid, picloram, and glyphosate, among others. The data indicate that herbicide use generally is proportionally higher in the study area than in the Nation, and that insecticide use in the study area generally is proportionally lower than in the Nation. Eight different agencies collected the waterquality data used in this report. Samples were collected by all agencies at a combined total of 155 surface-water sites and 121 ground-water sites. The sampled media included water, bed sediment, and tissues of fish and other aquatic wildlife. Some 273 samples for analysis of the herbicide 2,4–D were collected as part of the city of Arlington’s data-collection program. The herbicide was detected in 74 percent of the samples, but none exceeded the Maximum Contamination Level for drinking water. Dallas Water Utilities collected pesticide samples during a storm in February 1977. Samples were collected at 17 sites with detections of some pesticides in over 50 percent of the samples. Diazinon was detected in 56 percent of samples and 2,4–D was found in 56 percent of samples. Texas Parks and Wildlife Department collected samples from fish tissue for analyses of organochlorine pesticides from 15 sites in the Dallas-Fort Worth area. Chlordane concentrations in some of the samples exceeded the Food and Drug Administration’s action level of 300 micrograms per kilogram. The Texas Water Commission collected ground-water samples in the study area during 1990 for the major types of pesticides and none were detected. No arsenic was detected in samples from 121 wells in or near the study area. Organochlorine and organophosphate samples were collected beginning in 1974 and ending in 1991. Concentrations of organochlorine pesticides in bed sediment decrease with increasing distance downstream from the Dallas-Fort Worth urban area. Pesticide samples collected by the U.S. Geological Survey indicated significant rank correlation between number of detects of chlordane and the percent of the contributing watershed classified as urban land use. Dieldrin in bed sediment samples, and lindane, diazinon, and malathion, in water samples, also were significantly correlated with urban land use. Chlordane and dieldrin were significantly correlated with distance downstream from the Dallas-Fort Worth urban area. Review of all available data showed that pesticides were detected to a substantial degree in various sample media over the time period covered by this report. The authors were able to locate little pesticide-sample data for ground water or for tributary streams because sampling efforts historically have been concentrated on the mainstem Trinity River.

Texas↗
USGS1996

Ground-water quality assessment of the Georgia-Florida Coastal Plain study unit — Analysis of available information on nutrients, 1972-92

The U.S. Geological Survey is conducting an assessment of water quality in the Georgia-Florida Coastal Plain study unit as part of the National Water-Quality Assessment Program. An initial activity of the program is to compile and analyze existing water-quality data for nutrients in each study unit. Ground-water quality data were compiled from three data sources, the U.S. Geological Survey, Florida Department of Environmental Protection, and Georgia Geologic Survey. A total of 2,246 samples of ground water nutrient data for nitrogen and phosphorus species were compiled from these three data sources. Estimates of 1990 nitrogen and phosphorus inputs by county in the study area were calculated from livestock manure, fertilizers, septic tanks, and rainfall. Data for nitrate nitrogen concentrations in ground water were available from the greatest number of wells; samples from 1,233 wells were available in the U.S. Geological Survey, 820 wells from the Florida Department of Environmental Protection, and 680 wells from the Georgia Geologic Survey. The maximum contaminant level for nitrate nitrogen in drinking water of 10 milligrams per liter was exceeded in a higher percentage of samples from the U.S. Geological Survey, mostly because this data contained numerous samples near known contamination areas. The maximum contaminant level for nitrate nitrogen was exceeded in 3 percent of samples from Upper Floridan aquifer and 12 percent of samples from surficial aquifer system in U.S. Geological Survey data and less than 1 percent and 2 percent of samples from the Upper Floridan aquifer and surficial aquifer system, respectively, in Florida Department of Environmental Protection data. In Georgia Geologic Survey data, 1 percent of samples had concentrations of nitrate nitrogen exceeding 10 milligrams per liter. Nutrient concentration data were grouped into categories based on land use, hydrogeology (aquifer and confinement of the Upper Floridan aquifer), and land resource provinces (Central Florida Ridge, Coastal Flatwoods and Southern Coastal Plain) for the surficial aquifer system. The highest median nitrate nitrogen concentrations in the U.S. Geological Survey data were 0.4 milligrams per liter in ground-water samples from the unconfined Upper Floridan aquifer in agricultural areas and 9.0 milligrams per liter in samples from the surficial aquifer system in agricultural areas in the Central Florida Ridge. In Florida Department of Environmental Protection data, the highest median nitrate nitrogen concentrations were much lower and did not exceed 0.2 milligrams per liter in either the Upper Floridan aquifer or the surficial aquifer system. In Georgia Geologic Survey data the highest median nitrate nitrogen concentration was 1.4 milligrams per liter in agricultural areas in the Coastal Flatwoods. Highest median concentrations of total nitrogen of 10 milligrams per liter (includes nitrate, ammonia, and organic nitrogen) were in U.S. Geological Survey data in the surficial aquifer system in agricultural areas in the Central Florida Ridge. Median concentrations of ammonia nitrogen, orthophosphate phosphorus, and total phosphorus did not exceed 0.5 milligrams per liter in all categories from the Upper Floridan aquifer or the surficial aquifer system.

Florida, Georgia↗
USGS1996

Evaluation of selected information on splitting devices for water samples

Four devices for splitting water samples into representative aliquots are used by the U.S. Geological Survey's Water Resources Division. A thorough evaluation of these devices (14-liter churn, 8-liter churn, plastic cone, and Teflon cone) encompasses a wide variety of concerns, based on both chemical and physical considerations. This report surveys the existing data (as of April 1994) on cleaning efficiency and splitting capability of these devices and presents the data in a systematic framework for evaluation. From the existing data, some of these concerns are adequately or partially addressed, but the majority of concerns could not be addressed because of the lack of data. In general, the existing cleaning and transport protocols are adequate at the milligram per liter level, but the adequacy is largely unknown for trace elements and organic chemicals at lower concen- trations. The existing data indicate that better results are obtained when the splitters are cleaned in the laboratory rather than in the field. Two conclusions that can be reached on the splitting capability of solids are that more work must be done with all four devices to characterize and quantify their limitations and range of usefulness, and that the 14-liter churn (and by association, the 8-liter churn) is not useful in obtaining representative splits of sand-sized particles.

Water-Resources Investigations Report↗
USGS1996

Evaluation of the streamflow-gaging network of Alaska in providing regional streamflow information

In 1906, the U.S. Geological Survey (USGS) began operating a network of streamflow-gaging stations in Alaska. The primary purpose of the streamflow- gaging network has been to provide peak flow, average flow, and low-flow characteristics to a variety of users. In 1993, the USGS began a study to evaluate the current network of 78 stations. The objectives of this study were to determine the adequacy of the existing network in predicting selected regional flow characteristics and to determine if providing additional streamflow-gaging stations could improve the network's ability to predict these characteristics. Alaska was divided into six distinct hydrologic regions: Arctic, Northwest, Southcentral, Southeast, Southwest, and Yukon. For each region, historical and current streamflow data were compiled. In Arctic, Northwest, and Southwest Alaska, insufficient data were available to develop regional regression equations. In these areas, proposed locations of streamflow-gaging stations were selected by using clustering techniques to define similar areas within a region and by spatial visual analysis using the precipitation, physiographic, and hydrologic unit maps of Alaska. Sufficient data existed in Southcentral and Southeast Alaska to use generalized least squares (GLS) procedures to develop regional regression equations to estimate the 50-year peak flow, annual average flow, and a low-flow statistic. GLS procedures were also used for Yukon Alaska but the results should be used with caution because the data do not have an adequate spatial distribution. Network analysis procedures were used for the Southcentral, Southeast, and Yukon regions. Network analysis indicates the reduction in the sampling error of the regional regression equation that can be obtained given different scenarios. For Alaska, a 10-year planning period was used. One scenario showed the results of continuing the current network with no additional gaging stations and another scenario showed the results of adding gaging stations to the network. With the exception of the annual average discharge equation for Southeast Alaska, by adding gaging stations in all three regions, the sampling error was reduced to a greater extent than by not adding gaging stations. The proposed streamflow-gaging network for Alaska consists of 308 gaging stations, of which 32 are designated as index stations. If the proposed network can not be implemented in its entirety, then a lesser cost alternative would be to establish the index stations and to implement the network for a particular region.

Water-Resources Investigations Report↗
USGS1996

Water-quality assessment of the Ozark Plateaus study unit, Arkansas, Kansas, Missouri, and Oklahoma — Summary of information on pesticides, 1970–90

Historical pesticide data from 1970-90 were compiled for 140 surface-water, 92 ground-water, 55 streambed-sediment, and 120 biological-tissue sampling sites within the Ozark Plateaus National Water-Quality Assessment Program study unit. Surface-water, bed-sediment, and biological-tissue sites have drainage basins predominantly in the Springfield and Salem Plateaus; ground-water sites are predominantly located in the Osage Plains and Mississippi Alluvial Plain. Many sites were sampled only once or twice during this period. A large percentage of the samples were collected in the mid-1970's and early 1980's for surface water, 1990 for ground water, the late 1980's for surface water, 1990 for ground water, the late 1980's for bed sediment, and the early 1980's for biological tissue. Pesticide use was approximately 4.2 million pounds per year of active ingredients from 1982-85 in the study unit and was generally greatest in the Springfield and Salem Plateaus pasturelands and in the Osage Plains and Mississippi Alluvial Plain cropland areas. The most frequently applied pesticide in the study unit was 2,4-D. Alachlor was the second most applied pesticide. Corn, pasture, rice, sorghum, and soybeans received approximately 90 percent of the pesticides applied within the study unit. The highest pesticide application rate per acre occurred on these crops in the Osage Plains and Mississippi Alluvial Plain. Pastureland was the predominant crop type in 50 of the 94 counties in the study unit. Toxaphene, the pesticide having the most number of detections in surface water, was found in 17 of 866 samples from 5 of 112 sites. Concentrations ranged from 0.1 to 6.0 micrograms per liter. Six other pesticides or pesticide metabolites were detected in 12 or more surface-water samples: DDE, dieldrin, DDT, aldrin, 2,4-D, and lindane. The maximum concentration for these pesticides was less than 1.0 micrograms per liter. Atrazine, the pesticide having the most number of detections in ground water, was found in 15 of 95 samples from 15 of 79 wells with concentrations ranging from 0.1 to 8.2 micrograms per liter. Metolachlor, alachlor, and prometon were detected more than once with maximum concentrations less than 1.0 micrograms per liter, except for prometon (2.4 micrograms per liter). Chlordane was the pesticide having the most number of detections in bed sediment and biological tissue. Chlordane was detected in 12 of 73 samples from 10 of 45 bed-sediment sites with concentrations ranging from 2.0 to 240 micrograms per kilogram. In biological tissue, chlordane was found in 93 of 151 samples from 39 of 53 sites with concentrations ranging from 0.009 to 8.6 milligrams per kilogram. Other pesticides or pesticide metabolites detected more than once in bed sediment include DDT, DDD, p,p'-DDE, DDE, and hexachlorobenzene and in biological tissue include DDT, p,p'-DDE, and hexachlorobenzene. Quality criteria or standards have been established for 15 of the pesticides detected in the study unit. For surface-water samples, the drinking water maximum contaminant level for alachlor was exceeded in one sample from one site in 1982. For ground-water samples, the drinking water maximum contaminant level for atrazine was exceeded in four samples from four wells in 1990. For biological-tissue samples collected during the years 1982-89, the fish tissue action levels for chlordane (19 sites; 26 samples), heptachlor epoxide (3 sites; 3 samples), p,p'-DDE (2 sites; 2 samples), dieldrin (2 sites, 2 samples), and mirex (1 site; 1 sample) were exceeded. For bed-sediment samples, quality criteria or standards were not exceeded for any pesticide. Pesticides do not pose any widespread or persistent problems in the study unit, based on the limited number of samples that exceeded quality criteria and standards.

Arkansas, Kansas, Missouri, Oklahoma↗
USGS1996

Water-quality assessment of the western Lake Michigan drainages: Analysis of available information on nutrients and suspended sediment, water years 1971-90

In 1986, Congress appropriated funds for the U.S. Geological Survey (USGS) to develop the pilot phase of the National Water-Quality Assessment (NAWQA) Program. The long-term goals of this program are to (1) provide a nationally consistent description of current water-quality conditions for a large part of the Nation's water resources; (2) define. long-term trends (or lack of trends) in water quality; and (3) identify, describe, and explain, as possible, the major factors that affect the observed water-quality conditions and trends. To fulfill the goals of the NAWQA program, the USGS plans to examine 60 areas (study units) across the United States during full implementation of the program. In 1991, the NAWQA program went into full implementation with the intensive investigation of 20 of these study units; one of these study units is the Western Lake Michigan Drainages (WMIC) study unit.

Michigan, Wisconsin↗
USGS1996

Water-quality assessment of southern Florida: An overview of available information on surface- and ground-water quality and ecology

This report summarizes water-quality conditions, issues of concern, and management efforts underway in southern Florida. The report is designed to provide a conceptual framework for the Southern Florida National Water Quality Assessment (NAWQA) study that began in 1994. The report makes reference to the most important water-quality literature pertaining to southern Florida, to water-quality studies that are underway or planned, and to topics which are of high priority in the study unit. These topics include: the availability and suit ability of water for competing demands; nutrient enrichment of the Everglades; transport, degradation, and effects of pesticides; and the sources and cycling of mercury in the ecosystem. The report also includes a retrospective analysis and conceptual presentation of nutrient loading, which is a high priority for the national NAWQA Program and for regional water-quality managers. Nutrient contributions from point and nonpoint sources are estimated for nine basins in the study area and are discussed in relation to land use. Fertilizer is the dominant source of phosphorus in eight basins and the dominant source of nitrogen in at least five basins. Atmospheric sources of nitrogen contribute more than 20 percent of the total nitrogen input to all basins and are the dominant source of nitrogen input to Lake Okeechobee and the Everglades. Nutrient loads are also estimated in selected canal and river outflows in southern Florida to provide a spatial overview of the magnitude of nutrient loading to coastal waters. Annual phosphorus loads from the Peace River are the highest in the study unit; annual phosphorus loads from the Caloosahatchee River and the major Palm Beach canals are also high, compared to other parts of southern Florida. Estimated annual loads of phosphorus from parts of the Big Cypress Basin and the S-12 water-control structures of the Tamiami Canal are low compared with estimated phosphorus loads in outflows in the northern part of the study unit. Annual nitrogen loads in southern Florida were highest in outflows from the Caloosahatchee River Basin and the major Palm Beach canals. Nitrogen loads in outflows from parts of the Big Cypress subbasin were lower than those estimated to the north.

Florida↗