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This circular contains short reports about many of the geologic studies carried out in Alaska by the U.S. Geological Survey and cooperating agencies during 1984. The topics cover a wide range in scientific and economic interest.
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Eurycea salamander taxa comprise 12 known species that inhabit springs and caves in south-central Texas. Many of these are threatened or endangered species, and some are found only at one location. A number of the neotenic salamanders might be at risk from habitat loss associated with declines in ground-water levels. Eurycea salamander habitats are associated with three aquifers in south-central Texas: (1) the Edwards-Trinity (Plateau) aquifer, (2) the Edwards (Balcones Fault Zone) aquifer, and (3) the Trinity aquifer. The Edwards (Balcones fault zone) aquifer is commonly separated into three segments: from southwest to northeast, the San Antonio segment, the Barton Springs segment, and the northern segment. The Trinity aquifer south of the Colorado River can be divided into three permeable zones, the upper, middle, and lower zone. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, developed this report (geodatabase) to aggregate the spatial data necessary to assess the potential effects of ground-water declines on known Eurycea habitat locations in south-central Texas. The geodatabase provides information about spring habitats, spring flow, cave habitats, aquifers, and projected water levels.
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The U.S. Geological Survey's Fort Collins Science Center (FORT) is one of 17 USGS biological science centers nationwide. FORT conducts research and develops technical applications to assist land managers in understanding and managing biological resources, habitats, and ecosystems. Although the majority of FORT's activities are conducted within the 15-state Central Region of the USGS, many FORT projects are national or international in scope. FORT serves all Department of the Interior land management bureaus and other natural resource agencies. In addition, FORT scientists partner with DOI and other federal entities such as CDC, DOE, EPA, NASA, NIH, and USDA to share expertise and resources. FORT also partners with several universities and works cooperatively with states and nongovernmental organizations. Products and services include reports and publications, predictive models and software, maps and GIS products, and other technical assistance in the form of meetings, workshops, training, field visits, and needs assessments.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
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The U.S. Geological Survey, in cooperation with the Kentucky Division of Water, has compiled the reported permitted public water-supply-withdrawal data for Kentucky for 2005. Water-withdrawal data for 1995 and 2000 were previously published in Solley and others (1998) and Hutson and others (2004), respectively. This report is a graphical representation of permitted withdrawals for 1995, 2000, and 2005. Public suppliers that are regulated through the Kentucky Division of Water, Water-Withdrawal Permitting Program, withdrew a total of 496, 525, and 558 million gallons per day (Mgal/d) in 1995, 2000, and 2005, respectively. In 2005, 489 Mgal/d (88 percent) came from surface-water sources, and 69 Mgal/d (12 percent) came from ground-water sources. Small increases and decreases in permitted public water-supply withdrawals can be attributed to population changes. Large increases and decreases can be attributed to merging of supply systems, change(s) in source, or purchases from other counties.
The range of the endangered black abalone ( Haliotis cracherodii ) is divided into the North Central California region, the Central California region, the Southern California Mainland region, the Channel Islands region, and the Baja California region by the National Marine Fisheries Service for management purposes. San Nicolas Island is one of eight subregions of the Channel Islands region. The black abalone recovery plan establishes five demographic criteria for the possible delisting or downlisting of the species. The U.S. Geological Survey monitors nine long-term intertidal black abalone sites at San Nicolas Island, California, in cooperation with the U.S. Navy, which owns the island. This report uses data collected between 2013 and 2022 and the delisting criteria to analyze and describe the density, recruitment, size structure, and population trends at the nine U.S. Geological Survey monitoring sites at San Nicolas Island.
Forty-eight surveyed stream-channel cross sections were established along Redwood Creek, Humboldt County, California between 1973 and 1974. Eighty-three cross sections were established at selected sites along tributaries to Redwood Creek between 1974 and 1976. Eleven surveyed stream channel cross sections were established in the Mill Creek drainage basin, Del Norte County, California in the summer of 1974. All cross-sections have been resurveyed at least annually since they were established. All work was done in cooperation with the National Park Service. Data tabulated in this report summarize changes at cross sections since release of previous reports. Data from the Redwood Creek cross sections are tabulated for the following periods: initiation of observation to summer 1978, summer 1975 to summer 1976, and summer 1977 to summer 1978. Data from the Redwood Creek tributary cross sections are tabulated for various periods between 1974 and 1978. Data from the Mill Creek cross sections are presented for the period of summer of 1975 to summer 1978. Thirteen figures are included to aid in understanding the tabulated data.
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Continuous slope-area (CSA) streamgages have been developed and implemented by the U.S. Geological Survey (USGS) to enable the recording of discharge hydrographs in areas where direct discharge measurements cannot be made. The flashy nature of streamflow in parts of the arid Southwest and remote location of many sites make discharge measurements difficult or impossible to obtain. Consequently, available discharge measurements may be insufficient to develop accurate rating curves, which relate discharge to continuously recorded stage measured at standard streamgages. Nine CSA streamgages have been installed in Maricopa County, Arizona, since 2004 in cooperation with the Flood Control District of Maricopa County. This report presents the data and analysis of computed discharges from those streamgages, along with descriptions of the streamgage site and stream properties. Analyses of sources of errors and the impact stage data errors have on calculated discharge time series are considered, along with issues in data reduction. Steeper, longer stream reaches are generally less sensitive to measurement error. Other issues considered are pressure transducer drawdown, capture of flood peaks with discrete stage data, selection of stage record for development of rating curves, and minimum stages for the calculation of discharge.