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At least 1,009 records · Page 56Linked to original sources
USGS2012

Steroidal hormones and other endocrine active compounds in shallow groundwater in nonagricultural areas of Minnesota—Study design, methods, and data, 2009–10

The U.S. Geological Survey, in cooperation with the Minnesota Pollution Control Agency, completed a study on the occurrence of steroidal hormones and other endocrine active compounds in shallow groundwater in nonagricultural areas of Minnesota during 2009–10. This report describes the study design and methods, and presents the data collected on steroidal hormones and other related compounds. Environmental and quality-control samples were collected from 40 wells as part of this study. Samples were analyzed by the U.S. Geological Survey National Water Quality Laboratory for 16 steroidal hormones and 4 other related compounds, of which all but 2 compounds are endocrine active compounds. Most of the water samples did not contain detectable concentrations of any of the 20 compounds analyzed. Water samples from three wells had detectable concentrations of one or more compounds. Bisphenol A was detected in samples from three wells, and trans-diethylstilbestrol was detected in one of the samples in which bisphenol A also was detected.

Minnesota↗
USGS1976

Geochemical maps showing the distribution and abundance of copper in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of copper in four sample media: (A) the oxide residue (the oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh stream sediment, (C) the ash of streambank sod (mixed organic and inorganic material) collected beneath the water level, and (D) the ash of aquatic bryophytes (mosses). The copper data are plotted on base maps showing generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they are closely associated with strongly anomalous metal values either in the same sample medium or with anomalous values in other sample media. The ranges of values represented by the symbols are shown on the histograms which accompany the geochemical maps. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).

Alaska↗
USGS1976

Geochemical maps showing the distribution and abundance of molybdenum in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of molybdenum in four sample media: (A) the oxide residue (the oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh stream sediment, (C) the ash of streambank sod (mixed organic and inorganic material) collected beneath the water level, and (D) the ash of aquatic bryophytes (mosses). The molybdenum data are plotted on base maps showing generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they are closely associated with strongly anomalous metal values either in the same sample medium or with anomalous values in other sample media. The ranges of values represented by the symbols are shown on the histograms which accompany the geochemical maps. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).

Alaska↗
USGS1976

Geochemical maps showing the distribution and abundance of lead in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of lead in four sample media: (A) the oxide residue (the oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh stream sediment, (C) the ash of streambank sod (mixed organic and inorganic material) collected beneath the water level, and (D) the ash of aquatic bryophytes (mosses). The geochemical data are plotted on base maps showing generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they are closely associated with strongly anomalous metal values either in the same sample medium or with anomalous values in other sample media. The ranges of values represented by the symbols are shown on the histograms which accompany the geochemical maps. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).

Alaska↗
USGS1976

Geochemical maps showing the distribution and abundance of zinc in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of zinc in four sample media: (A) the oxide residue (oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh steam sediment, (C) the ash of streambank sod (mixed organic and inorganic material) collected beneath the water level, and (D) the ash of aquatic bryophytes (mosses). The map symbols show sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denote strongly anomalous values. Because the small black symbols represent weakly anomalous values, we consider them to be significant only where they correlate with strongly anomalous metal values either in the same or in other sample media. The ranges of values represented by the symbols are shown on the histograms that accompany the geochemical maps. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies the folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976.)

Alaska↗
USGS1976

Geochemical maps showing the distribution and abundance of arsenic and mercury in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of arsenic and mercury in the minus-80-mesh stream sediment and of arsenic in the ash of streambank sod (mixed organic and inorganic material) collected beneath the water level. The geochemical data are plotted on a base map that shows generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they are closely associated with strongly anomalous metal values either in the same sample medium or with anomalous values in other sample media. The ranges of values represented by the symbols are shown on the histograms that accompany the geochemical maps. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).

Alaska↗
USGS1976

Geochemical maps showing the distribution and abundance of tin in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of tin in three sample media: (A) the oxide residue (the oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh stream sediment, and (C) the ash of aquatic bryophytes (mosses). The geochemical data are plotted on a base map that shows generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they correlate with strongly anomalous metal values either in the same or other sample media. The ranges of values were determined from the histograms and other statistical data shown for each of the sample media. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).

Alaska↗
USGS1976

Geochemical maps showing the distribution and abundance of beryllium in the Tanacross Quadrangle, Alaska

This series of geochemical maps shows the distribution of beryllium in three sample media: (A) the oxide residue (the oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh stream sediment, and (C) the ash of aquatic bryophytes (mosses). The geochemical data are plotted on a base map that shows generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they correlate with strongly anomalous metal values either in the same or in other sample media. The ranges of values represented by the map symbols are shown on the histograms that accompany the geochemical maps. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).

Alaska↗
USGS2009

Sidescan-Sonar Imagery and Surficial Geologic Interpretations of the Sea Floor in Western Rhode Island Sound

The U.S. Geological Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA) have been working together to interpret sea-floor geology along the northeastern coast of the United States. In 2004, the NOAA Ship RUDE completed survey H11322, a sidescan-sonar and bathymetric survey that covers about 60 square kilometers of the sea floor in western Rhode Island Sound. This report interprets sidescan-sonar and bathymetric data from NOAA survey H11322 to delineate sea-floor features and sedimentary environments in the study area. Paleozoic bedrock and Cretaceous Coastal Plain sediments in Rhode Island Sound underlie Pleistocene glacial drift that affects the distribution of surficial Holocene marine and transgressional sediments. The study area has three bathymetric highs separated by a channel system. Features and patterns in the sidescan-sonar imagery include low, moderate, and high backscatter; sand waves; scarps; erosional outliers; boulders; trawl marks; and dredge spoils. Four sedimentary environments in the study area, based on backscatter and bathymetric features, include those characterized by erosion or nondeposition, coarse-grained bedload transport, sorting and reworking, and deposition. Environments characterized by erosion or nondeposition and coarse-grained bedload transport are located in shallower areas and environments characterized by deposition are located in deeper areas; environments characterized by sorting and reworking processes are generally located at moderate depths.

Open-File Report↗
USGS2014

Preliminary bedrock and surficial geologic map of the west half of the Sanders 30' x 60' quadrangle, Navajo and Apache Counties, northern Arizona

The bedrock and surficial geologic map of the west half of the Sanders 30' x 60' quadrangle was completed in a cooperative effort of the U.S. Geological Survey (USGS) and the Navajo Nation to provide regional geologic information for management and planning officials. This report provides baseline geologic information that will be useful in future studies of groundwater and surface water resources, geologic hazards, and the distribution of soils and plants. The west half of the Sanders quadrangle encompasses approximately 2,509 km 2 (980 mi 2 ) within Navajo and Apache Counties of northern Arizona and is bounded by lat 35°30' to 35° N., long 109°30' to 110° W. The majority of the land within the map area lies within the Navajo Nation. South of the Navajo Nation, private and State lands form a checkerboard pattern east and west of Petrified Forest National Park. In the west half of the Sanders quadrangle, Mesozoic bedrock is nearly flat lying except near folds. A shallow Cenozoic erosional basin that developed about 20 Ma in the western part of the map area cut across late Paleozoic and Mesozoic rocks that were subsequently filled with flat-lying Miocene and Pliocene mudstone and argillaceous sandstone and fluvial sediments of the Bidahochi Formation and associated volcanic rocks of the Hopi Buttes volcanic field. The Bidahochi rocks are capped by Pliocene(?) and Pleistocene fluvial sediments and Quaternary eolian and alluvial deposits. Erosion along northeast-southwest-oriented drainages have exposed elongated ridges of Bidahochi Formation and basin-fill deposits that are exposed through shallow eolian cover of similarly oriented longitudinal dunes. Stokes (1964) concluded that the accumulation of longitudinal sand bodies and the development of confined parallel drainages are simultaneous processes resulting in parallel sets of drainages and ridges oriented along the prevailing southwest wind direction on the southern Colorado Plateau.

Arizona↗
USGS2004

Determining sources of water and contaminants to wells in a carbonate aquifer near Martinsburg, Blair County, Pennsylvania, by use of geochemical indicators, analysis of anthropogenic contaminants, and simulation of ground-water flow

Water supply for the Borough of Martinsburg, Pa., is from two well fields (Wineland and Hershberger) completed in carbonate-bedrock aquifers in the Morrison Cove Valley. Water supply is plentiful; however, waters with high concentrations of nitrate are a concern. This report describes the sources of water and contaminants to the supply wells. A review of previous investigations was used to establish the aquifer framework and estimate aquifer hydraulic properties. Aquifer framework and simulation of ground-water flow in a 25-square-mile area using the MODFLOW model helped to further constrain aquifer hydraulic properties and identify water-source areas in the zone of contribution of ground water to the well fields. Flow simulation identified potential contaminant-source areas. Data on contaminants and geochemical characteristics of ground water at the well fields were compared to the results of flow simulation. The Woodbury Anticline controls the aquifer framework near the well fields and four carbonate-bedrock formations contain the primary aquifers. Three carbonate-bedrock aquifers of Ordovician age overlie the Gatesburg aquifer of Cambrian age on the flanks of the anticline. Fracture, not conduit, permeability was determined to be the dominant water-bearing characteristic of the bedrock. The horizontal hydraulic conductivity of the Gatesburg aquifer is about 36 feet per day. The other carbonate aquifers (Nittany/Stonehenge, Bellefonte/Axemann, and Coburn through Loysburg aquifers) overlying and flanking the Gatesburg aquifer have horizontal hydraulic conductivities of about 1 foot per day. Regional directions of ground-water flow are toward the major streams with Clover Creek as the major discharge point for ground water in the east. Ground-water flow to the well fields is anisotropic with a 5:1 preferential horizontal direction along strike of the axial fold of the anticline. Thus, the zone of contribution of ground water to the well fields is elongate in a north-south direction along the anticline axis, with the majority of the flow to the well fields originating from the south. Human activity in the areal extent of the zone of contribution to the well fields was the source of contaminants. The areal extent of the zone of contribution included both urban areas in the Borough and a large amount of agricultural land. By relating results of flow simulation, natural geochemistry, and analyses of anthropogenic (human-made) contaminants, the source areas for water and contaminants were determined with more confidence than by using only flow simulation. Analysis of natural geochemistry identified water sources from both limestone and dolomite aquifers. Geochemistry results also indicated fractures, not conduits, were the dominant source of water from aquifers; however, quantitative source identification was not possible. Chemical ratios of chloride and bromide were useful to show that all samples of ground water had sources with chemical contributions from land surface. Nitrogen isotope ratio analysis indicated animal manure as the possible primary source of nitrate in most ground water. Some of the nitrate in ground water had chemical fertilizer as a source. At the Wineland well field, chemical fertilizer was likely the source of nitrate. The nitrate in water from the Hershberger well field was from a mixture of fertilizer and animal-manure sources. Human sewage was ruled out as a major source of nitrate in water from the municipal wells by results showing 1) wastewater compounds in sewage were rarely detected and 2) a mass-balance calculation indicating the small contribution of nitrogen that could be attributed to septic systems.

Scientific Investigations Report↗
USGS2021

Discharge data collection and analysis and implications for surface-water/groundwater interactions in the lower Las Vegas Wash, Clark County, Nevada, 2016–18

The lower Las Vegas Wash represents the terminal surface drainage for the Las Vegas Valley in southern Nevada. In 1997, high concentrations of perchlorate were found in seeps contributing to discharge in this area and traced to an industrial byproduct from manufacturing operations in the mid-1900s at the nearby Basic Magnesium, Incorporated, plant. The discovery prompted a water-resources investigation by the Nevada Department of Environmental Protection (NDEP) to develop an understanding of the nearby groundwater flow system and the dynamics associated with surface-water flow in the Wash. In 2016, the U.S. Geological Survey was tasked with evaluating surface-water discharge in the lower Las Vegas Wash near locations where perchlorate concentrations from the groundwater system had been detected. Results of this study will assist NDEP with identifying areas of groundwater and surface-water interaction and help guide future cleanup and monitoring efforts. Streamflow discharge is evaluated along a 4-mile section of the lower Las Vegas Wash (referred to as the Wash) and used to describe surface-water and groundwater interactions between the Wash channel and bank sediments. Continuous discharge data were collected during a 2-year period (2016–18) at 5 gaging stations along the Wash. Additionally, multiple discrete measurements between gaging stations were collected during 4 synoptic sampling events between 2016 and 2018. A diurnal discharge pattern, controlled by upstream treated wastewater releases, provided high- and low-discharge markers that are used to compute downstream time-lags of peak and minimum flows. Computed time-lags are used to establish travel times between measurement sites, and difference in upstream and time-lagged downstream hydrographs are used to compute increases (gain) or decreases (loss) in discharge between gaging stations or between gaging stations and discrete measurements. Tributary surface-water inflows to the lower Las Vegas Wash from wastewater discharge, remediation efforts, and periodic flooding from rainfall runoff are included in computing differences in discharge. Differences between discharge data from delineated reaches are used to define locations of daily, monthly, and yearly streamflow gains from or losses to adjacent bank sediments. Construction of additional channel-stabilization weirs have occurred since the completion of this study and the associated change to streamflow dynamics may limit study results to the period analyzed; however, methods and processes described in this report can be used in future evaluations.

Nevada↗
USGS2003

Trends in suspended-sediment concentration at selected stream sites in Kansas, 1970–2002

Knowledge of erosion, transport, and deposition of sediment relative to streams and impoundments is important to those involved directly or indirectly in the development and management of water resources. Monitoring the quantity of sediment in streams and impoundments is important because: (1) sediment may degrade the water quality of streams for such uses as municipal water supply, (2) sediment is detrimental to the health of some species of aquatic animals and plants, and (3) accumulation of sediment in water-supply impoundments decreases the amount of storage and, therefore, water available for users. One of the objectives of the Kansas Water Plan is to reduce the amount of sediment in Kansas streams by 2010. During the last 30 years, millions of dollars have been spent in Kansas watersheds to reduce sediment transport to streams. Because the last evaluation of trends in suspended-sediment concentrations in Kansas was completed in 1985, 14 sediment sampling sites that represent 10 of the 12 major river basins in Kansas were reestablished in 2000. The purpose of this report is to present the results of time-trend analyses at the reestablished sediment data-collection sites for the period of about 1970–2002 and to evaluate changes in the watersheds that may explain the trends. Time-trend tests for 13 of 14 sediment sampling sites in Kansas for the period from about 1970 to 2002 indicated that 3 of the 13 sites tested had statistically significant decreasing suspended-sediment concentrations; however, only 2 sites, Walnut River at Winfield and Elk River at Elk Falls, had trends that were statistically significant at the 0.05 probability level. Increasing suspended-sediment concentrations were indicated at three sites although none were statistically significant at the 0.05 probability level. Samples from five of the six sampling sites located upstream from reservoirs indicated decreasing suspended-sediment concentrations. Watershed impoundments located in the respective river basins may contribute to the decreasing suspended-sediment trends exhibited at most of the sampling sites because the impoundments are designed to trap sediment. Both sites that exhibited statistically significant decreasing suspended-sediment concentrations have a large number of watershed impoundments located in their respective drainage basins. The relation between percentage of the watershed affected by impoundments and trend in suspended-sediment concentration for 11 sites indicated that, as the number of impoundments in the watershed increases, suspended-sediment concentration decreases. Other conservation practices, such as terracing of farm fields and contour farming, also may contribute to the reduced suspended-sediment concentrations if their use has increased during the period of analysis. Regression models were developed for 13 of 14 sediment sampling sites in Kansas and can be used to estimate suspended-sediment concentration if the range in stream discharge for which they were developed is not exceeded and if time trends in suspended-sediment concentrations are not significant. For those sites that had a statistically significant trend in suspended-sediment concentration, a second regression model was developed using samples collected during 2000–02. Past and current studies by the U.S. Geological Survey have shown that regression models can be developed between in-stream measurements of turbidity and laboratory-analyzed sediment samples. Regression models were developed for the relations between discharge and suspended-sediment concentration and turbidity and suspended-sediment concentration for 10 sediment sampling sites using samples collected during 2000–02.

Kansas↗
USGS2016

Sources of subsidence at the Salton Sea Geothermal Field

At the Salton Sea Geothermal Field (SSGF) in Southern California, surface deformation associated with geologic processes including sediment compaction, tectonic strain, and fault slip may be augmented by energy production activities. Separating the relative contributions from natural and anthropogenic sources is especially important at the SSGF, which sits at the apex of a complex tectonic transition zone connecting the southern San Andreas Fault with the Imperial Fault; but this has been a challenging task so far. Here we analyze vertical surface velocities obtained from the persistent scatterer InSAR method and find that two of the largest subsidence anomalies can be represented by a set of volumetric strain nuclei at depths comparable to geothermal well completion zones. In contrast, the rates needed to achieve an adequate fit to the magnitudes of subsidence are almost an order of magnitude greater than rates reported for annual changes in aggregate net-production volume, suggesting that the physical mechanism responsible for subsidence at the SSGF is a complicated interplay between natural and anthropogenic sources.

California↗
USGS2010

A Servicewide Benthic Mapping Program for National Parks

In 2007, the National Park Service (NPS) Inventory and Monitoring Program directed the initiation of a benthic habitat mapping program in ocean and coastal parks in alignment with the NPS Ocean Park Stewardship 2007-2008 Action Plan. With 74 ocean and Great Lakes parks stretching over more than 5,000 miles of coastline across 26 States and territories, this Servicewide Benthic Mapping Program (SBMP) is essential. This program will deliver benthic habitat maps and their associated inventory reports to NPS managers in a consistent, servicewide format to support informed management and protection of 3 million acres of submerged National Park System natural and cultural resources. The NPS and the U.S. Geological Survey (USGS) convened a workshop June 3-5, 2008, in Lakewood, Colo., to discuss the goals and develop the design of the NPS SBMP with an assembly of experts (Moses and others, 2010) who identified park needs and suggested best practices for inventory and mapping of bathymetry, benthic cover, geology, geomorphology, and some water-column properties. The recommended SBMP protocols include servicewide standards (such as gap analysis, minimum accuracy, final products) as well as standards that can be adapted to fit network and park unit needs (for example, minimum mapping unit, mapping priorities). SBMP Mapping Process. The SBMP calls for a multi-step mapping process for each park, beginning with a gap assessment and data mining to determine data resources and needs. An interagency announcement of intent to acquire new data will provide opportunities to leverage partnerships. Prior to new data acquisition, all involved parties should be included in a scoping meeting held at network scale. Data collection will be followed by processing and interpretation, and finally expert review and publication. After publication, all digital materials will be archived in a common format. SBMP Classification Scheme. The SBMP will map using the Coastal and Marine Ecological Classification Standard (CMECS) that is being modified to include all NPS needs, such as lacustrine ecosystems and submerged cultural resources. CMECS Version III (Madden and others, 2010) includes components for water column, biotic cover, surface geology, sub-benthic, and geoform. SBMP Data Archiving. The SBMP calls for the storage of all raw data and final products in common-use data formats. The concept of 'collect once, use often' is essential to efficient use of mapping resources. Data should also be shared with other agencies and the public through various digital clearing houses, such as Geospatial One-Stop (http://gos2.geodata.gov/wps/portal/gos). To be most useful for managing submerged resources, the SBMP advocates the inventory and mapping of the five components of marine ecosystems: surface geology, biotic cover, geoform, sub-benthic, and water column. A complete benthic inventory of a park would include maps of bathymetry and the five components of CMECS. The completion of mapping for any set of components, such as bathymetry and surface geology, or a particular theme (for example, submerged aquatic vegetation) should also include a printed report.

Open-File Report↗
USGS2024

Glacier National Park bumble bee survey report 2023

Glacier National Park's grasslands provide important contributions to the character and ecology of the park. In 1999-2001, Glacier National Park (hereafter, the park) established 155 permanent vegetation monitoring plots to inventory grassland vegetation communities east of the Continental Divide. In June of 2023, the Blackfeet Nation (Amskapi Piikuni) re-introduced a herd of free roaming bison on adjacent tribal land (the linnii Initiative), and those bison may enter the park. Because grasslands are important areas for bison grazing, and because biological communities have likely changed since the initial inventories, the park’s vegetation program began revisiting grassland monitoring plots in 2018. New data will provide insights into how these grasslands, and the wildlife that depend on them, have changed over the past two decades. Data on pollinators in these grasslands, however, are limited. Bison have been shown to influence plant communities, for example, by increasing herbaceous forb diversity and drought resilience (Elson and Hartnett 2017; Ratajczak et al. 2022). These changes directly influence resources available to foraging pollinators. To provide understanding of pollinators prior to bison reintroduction, bumble bee surveying at these grassland plots began in 2020 and has continued through 2023. Target sites for 2020-2022 focused on collecting data at plots where new vegetation surveys were recently completed to match current vegetation data with the bumble bee data.

Montana↗
USGS2021

Precipitation-runoff processes in the Merced River Basin, Central California, with prospects for streamflow predictability, water years 1952–2013

The U.S. Geological Survey, in cooperation with the California Department of Water Resources (DWR), has constructed a new spatially detailed Precipitation-Runoff Modeling System (PRMS) model for the Merced River Basin, California, which is a tributary of the San Joaquin River in California. Operated through an Object User Interface (OUI) with Ensemble Streamflow Prediction (ESP) and daily climate distribution preprocessing functionality, the model is calibrated primarily to simulate (and eventually, forecast) year-to-year variations of inflows to Lake McClure during the critical April–July snowmelt season. The model is intended to become part of a suite of methods used by DWR for estimating daily streamflow from the Merced River Basin, especially during the snowmelt season. This study describes the results of the application of an analysis tool that simulates responses to climate and land-use variations at a higher spatial resolution than previously available to DWR. A geographic information system was used to delineate the model domain, that is, areas draining to a single outlet at U.S. Geological Survey streamflow-gaging station 11270900, Merced River below Merced Falls Dam, near Snell, CA (also known as California Data Exchange Center station MRC), and subdrainage areas, including four draining to internal gages used as calibration targets. Using this delineation, three contiguous subbasins were recognized and, along with the model domain and nested calibration targets, are the simulation units evaluated in this report. An auto-calibration tool, LUCA (Let Us CAlibrate), was used for each calibration node, from headwaters to basin outlet, and then parameters were manually adjusted to complete the calibration. The main objective was to match April–July snowmelt seasonal discharge values of simulated streamflow to observed (measured or reconstructed) discharge values. Calibration or validation periods used site-specific streamflows—mostly from October 1, 1988, through September 30, 2013—but differed according to the period-of-record available for the measurements collected at internal gages or reconstructed flows for the single outlet. The accuracy of the Merced PRMS streamflow simulations varied seasonally, as compared to observed values. Based on statistical results, the Merced PRMS model satisfactorily simulated snowmelt seasonal streamflows. April–July calibrations for all areas had small negative bias (not greater than 7 percent) and low relative error (less than 8 percent). Less satisfactory performance for other seasons was attributed to several factors: (1) high uncertainty in low or zero flows in summer and fall, (2) lack of accounting for basin withdrawals and anthropogenic water use, (3) unavailability and (or) inaccuracy of observed (measured) meteorological input data, and (4) uncertainty in reconstructed streamflow data. With some additional refinement, the Merced PRMS model may be used for forecasting seasonal and longer-term streamflow variations; evaluating forecasted and past climate and land cover changes; providing water-resource managers with a consistent and documented method for estimating streamflow at ungaged sites within the basin; and aiding environmental studies, hydraulic design, water management, and water-quality projects in the Merced River Basin.

California↗
USGS1978

Ground-water data, 1974-76, Indian Wells Valley, Kern, Inyo, and San Bernardino Counties, California

Water-level measurements were made annually in 115 wells in Indian Wells Valley, Kern, Inyo, and San Bernardino Counties, Calif., in 1974-76. In the Inyokern area the average water-level decline was 2.0 ft for two wells between October 1973 and November 1976. In the intermediate area the average decline was 6.2 ft for five wells between October 1973 and December 1976. In the Ridgecrest area the average decline was 4.5 ft for four wells between October 1973 and December 1976 but was 10.3 ft for one well during the same period. Reported metered ground-water pumpage from Indian Wells Valley totaled 14,400 acre-ft in 1974, 14,500 acre-ft in 1975, and 14,100 acre-ft in 1976. These figures may not completely reflect the total pumpage from the basin due to changing patterns of land use and new pumping sources. Chemical analyses were made of 102 water samples collected from 42 wells during 1974-76. The analyses show large variance of quality of ground water in Indian Wells Valley. (Woodard-USGS)

Open-File Report↗