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At least 1,765 records · Page 98Linked to original sources
USGS1996

Level II scour analysis for Bridge 15 (BRIDTH00220015) on Town Highway 22, crossing Dailey Hollow Branch, Bridgewater, Vermont

This report provides the results of a detailed Level II analysis of scour potential at structure BRIDTH00220015 on town highway 22 crossing Dailey Hollow Branch, Bridgewater, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in Appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in Appendix D. The site is in the Green Mountain section of the New England physiographic province of central Vermont in the town of Bridgewater. The 1.73-mi2 drainage area is a predominantly rural and forested basin. In the vicinity of the study site, the left and right banks have dense tree cover. The upstream right bank of Dailey Hollow Branch is adjacent to town highway 22. In the study area, Dailey Hollow Branch has a sinuous channel with a slope of approximately 0.035 ft/ft, an average channel top width of 30 ft and an average channel depth of 4 ft. The predominant channel bed material is cobble with a median grain size (D50) of 108 mm (0.354 ft). The geomorphic assessment at the time of the Level I and Level II site visit on November 1 and 2, 1994, indicates that the reach is stable. The town highway 22 crossing of Dailey Hollow Branch is a 22-ft-long, one-lane bridge consisting of one 22-ft. steel-beam span (Vermont Agency of Transportation, written communication, August 24, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. Type-1 stone fill (less than 12 inches diameter) protects the left abutment, but it’s condition was reported as eroded. Type-2 stone fill (less than 36 inches diameter) protects the upstream left wingwall; it’s condition was reported as slumping.The channel is skewed approximately 40 degrees to the opening while the opening-skew-to-roadway is 0 degrees. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E. Scour depths and rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and others, 1993). Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 0.0 to 0.2 ft. with the worst-case contraction scour occurring at the 500-year discharge. Abutment scour ranged from 4.2 to 6.4 ft. The worst-case abutment scour also occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and others, 1993, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

Vermont↗
USGS2004

1999 Volcanic activity in Alaska and Kamchatka: Summary of events and response of the Alaska Volcano Observatory

The Alaska Volcano Observatory (AVO) monitors 41 historically active volcanoes along the Aleutian Arc. Twenty are seismically monitored and for the rest, the AVO monitoring program relies mainly on daily analysis of satellite images, pilot reports, and observations of local residents and ship's crews. In 1999, AVO responded to eruptive activity or suspect volcanic activity at 7 volcanic centers: Wrangell, Shrub mud volcano, Iliamna, Veniaminof, Pavlof, Shishaldin, and Vsevidof volcanoes. Of these, in 1999, AVO had real-time, continuously recording seismic networks at Iliamna, and Shishaldin. The phrase “suspect volcanic activity” (SVA), used to characterize several responses, is an eruption report or report of unusual activity that is subsequently determined to be normal or enhanced fumarolic activity, weather-related phenomena, or a non-volcanic event. In addition to responding to eruptive activity at Alaska volcanoes, AVO also disseminated information for the Kamchatkan Volcanic Eruption Response Team (KVERT) about the 1999 activity of four Russian volcanoes: Sheveluch, Klyuchevskoy, Bezimianny, and Karymsky volcanoes.

Alaska↗
USGS2000

Water-quality characteristics for selected streams in Lawrence County, South Dakota, 1988-92

During the 1980’s, significant economic development and population growth began to occur in Lawrence County in the northern part of the Black Hills of western South Dakota. Rising gold prices and heap-leach extraction methods allowed the economic recovery of marginal gold ore deposits, resulting in development of several large-scale, open-pit gold mines in Lawrence County. There was increasing local concern regarding potential impacts on the hydrologic system, especially relating to the quantity and quality of water in the numerous streams and springs of Lawrence County. In order to characterize the water quality of selected streams within Lawrence County, samples were collected from 1988 through 1992 at different times of the year and under variable hydrologic conditions. During the time of this study, the Black Hills area was experiencing a drought; thus, most samples were collected during low-flow conditions. Streamflow and water-quality characteristics in Lawrence County are affected by both geologic conditions and precipitation patterns. Most streams that cross outcrops of the Madison Limestone and Minnelusa Formation lose all or large part of their streamflow to aquifer recharge. Streams that are predominantly spring fed have relatively stable streamflow, varying slightly with dry and wet precipitation cycles. Most streams in Lawrence County generally have calcium magnesium bicarbonate type waters. The sites from the mineralized area of central Lawrence County vary slightly from other streams in Lawrence County by having higher concentrations of sodium, less bicarbonate, and more sulfate. False Bottom Creek near Central City has more sulfate than bicarbonate. Nitrogen, phosphorous, and cyanide concentrations were at or near the laboratory reporting limits for most sites and did not exceed any of the water-quality standards. Nitrite plus nitrate concentrations at Annie Creek near Lead, Whitetail Creek at Lead, Squaw Creek near Spearfish, and Spearfish Creek below Robison Gulch were somewhat higher than at other sites. Mining activity, agricultural activity, and domestic development are possible sources of nitrogen to the streams. Increased mining activities were identified as the probable cause of increased nitrogen concentrations in Annie Creek. In the mineralized area of the northern Black Hills, detectable concentrations of trace elements are common in stream water, occasionally exceeding beneficial-use and aquatic-life criteria. In addition, many basins have been disturbed by both historical and recent mining operations and cleanup activities. The maximum dissolved arsenic concentration at Annie Creek near Lead (48 micrograms per liter) approached the current arsenic drinking-water standard. Concentrations at or greater than 5 micrograms per liter were found in samples from Annie Creek near Lead, Spearfish Creek above Spearfish, Whitetail Creek at Lead, and False Bottom Creek near Spearfish. Bear Butte Creek near Deadwood had one sample with a dissolved copper concentration that exceeded acute and chronic aquatic-life criteria. Bear Butte Creek near Deadwood had several manganese concentrations that exceeded the secondary maximum contaminant level of 50 micrograms per liter. Bed-sediment and water-quality data from selected sites in small drainage basins were used to determine if factors such as pH, arsenic concentrations in bed sediments, and calcite saturation control dissolved arsenic concentrations. Arsenic solubility is controlled by adsorption, mainly on ferrihydrite. In addition, adsorption/desorption of arsenic is controlled by the pH of the stream, with high arsenic concentrations appearing only at higher pH conditions (above 8). There are significant arsenic sources available to almost all the small streams of the northern Black Hills mining area, but arsenic is less mobile in streams that are not influenced to the higher pH values by calcite. Streams where arsenic is more mobile have lower iron concentrations in their bed sediments, and they have relatively high concentrations of calcite Additional water-quality data have been collected as part of other studies or monitoring programs by the South Dakota Department of Environment and Natural Resources, U.S. Environmental Protection Agency, U.S. Forest Service, and the U.S. Geological Survey. Summaries of selected data from these other sources are included as additional information.

South Dakota↗
USGS2007

U.S. Geological Survey Georgia Water Science Center and City of Brunswick–Glynn County Cooperative Water Program— Summary of activities, July 2005 through June 2006

Since 1959, the U.S. Geological Survey has conducted a cooperative water resources program (CWP) with the City of Brunswick and Glynn County in the Brunswick, Georgia, area. Since the late 1950s, the salinity of ground water in the Upper Floridan aquifer near downtown Brunswick, Georgia, has been increasing, and its occurrence has been detected across an area of increasing size. Pumping of the Upper Floridan aquifer near downtown Brunswick has lowered water levels in the aquifer and resulted in an upward hydraulic gradient between the highly saline parts of the Lower Floridan aquifer and the normally fresh Upper Floridan aquifer. Saltwater likely enters the Upper Floridan aquifer through localized, vertically oriented conduits of relatively high permeability and moves laterally in response to the distribution of stresses within the aquifer. The Brunswick-Glynn County CWP for fiscal year 2006 includes the operation and maintenance of 12 continuous water-level recorders. In addition, water-level data were collected from 52 wells and water from 70 wells was analyzed for chloride concentration during June 2005. Geophysical logs were obtained from one well to assess whether the cause of elevated chloride concentration could be due to leaky well casing. A summary of the Georgia Department of Natural Resources, Environmental Protection Division (GaEPD) Georgia Coastal Sound Science Initiative (CSSI) activities that directly benefit the CWP-Brunswick-Glynn County is included in this report. The GaEPD CSSI is a program of scientific and feasibility studies to support development of a final strategy to protect the Upper Floridan aquifer from saltwater contamination. These data presented in this report are needed by State and local authorities to manage water resources effectively in the coastal area of Georgia.

Georgia↗
USGS1979

Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Mount Hayes Quadrangle, Alaska

These summaries of references are designed to aid in library research on metallic and nonmetallic (other than mineral fuels and construction materials) mineral occurrences in the Mount Hayes quadrangle, Alaska. References to most reports of the Geological Survey, the U.S. Bureau of Mines, and the State of Alaska Division of Geological and Geophysical Surveys and its predecessor State and Territorial agencies released before September 1, 1978, are summarized. Certain, mainly statistical, reports such as the annual Minerals Yearbook of the U.S. Bureau of Mines and most biennial and annual reports of the State of Alaska Division of Geological and Geophysical Surveys and its predecessor State and Territorial agencies are not included.

Alaska↗
USGS1938

Floods of Ohio and Mississippi Rivers, January-February 1937, with a section on the Flood deposits of the Ohio River, January-February 1937

In January and February 1937 the Ohio and mid-Mississippi Rivers experienced floods which, over reaches many hundreds of miles in length, exceeded all previously recorded stages. When measured by the loss of life and property, extent of damage, and general disruption of human activities, these floods constituted a major catastrophe. The floods were caused by a succession of heavy rainstorms that began late in December 1936 and continued nearly to the end of the following January. Although the storms covered a considerable part of the lower Mississippi River Basin and almost the entire Ohio River Basin, the center of heaviest precipitation was in the middle and lower portions of the Ohio River Valley. The total storm period can be subdivided into several individual storms, which were more or less clearly demarked by short intervening periods of little or no precipitation. Although the individual storm periods were the same or nearly the same over wide areas, their subdivisions were somewhat different in the most widely separated parts of the affected areas, with intermediate gradations in the intervening areas. The heaviest rainfall--that of January 20 to 25--was centered in the lower Ohio Valley, and, falling as it did upon a region with soil saturated and waterways already running full, it had the effect of producing extreme floods. The small quantity of snow on the ground over the higher eastern parts of the area at the beginning of the storm period disappeared in a short time. Some of the precipitation occurred in the form of snow, but this snow and the associated cold weather were much less significant in their influence on the floods than in the misery and discomfort they caused to ill-sheltered flood refugees and flood-bound people. Sequence and time of the storms were such that in the upper and smaller tributary basins the associated flood rises tended to clear to a notable degree before the-next flood rises came; hence many of these tributaries were at no time in extreme flood. In the lower reaches of the largest tributaries, and especially on the middle and lower reaches of the Ohio River, there were extreme and almost continuously increasing accumulations of run-off, which culminated in the region of Louisville, Ky., in stages 10 or 11 feet higher than any previously known. The precipitation was heaviest in the Ohio River Basin, and the flood in the Mississippi River, like other notable floods of the past, was caused largely by the extraordinary contributions from the Ohio River. The river stages exceeded those previously recorded for the lower 700 miles on the Ohio River and for 250 miles .on the Mississippi River below the Ohio. At Cairo, Ill., at the mouth Of the Ohio River, the river stage was higher for a period of 19 days, from January 24 to February 11, than at any previous time on record. The height above previous flood stages diminished materially as the flood progressed down the Mississippi. The mean precipitation ever the Ohio River Basin during the storm period was. 12.85 inches. The snow on the ground at the beginning of the period is estimated to have been equivalent to a mean depth of 0.10 inch of water over the basin. Out of the total precipitation 8.9 inches appeared as flood flow. On January 26 the computed volume of water in the stream channels of the Ohio River Basin was 56,000,000 acre-feet, equivalent to a depth of 5.1 inches over the drainage basin. The maximum discharge of the Ohio River at its mouth was 1,880,000 second-feet on February 1. On February 2, the day of the crest stage at the mouth of the Ohio, the computed volume of water on the surface channel system was equivalent to a depth of 3.7 inches over the drainage basin, of which 2.4 inches was in the 337-mile reach of the Ohio River between Louisville, Ky., and the mouth. This water-supply paper presents records of stage and discharge for the period including the floods at about 250 measurement stations, records of stage and discharge for the period including the floods at about 250 measurement stations, records of storage in many reservoirs, a summary of peak discharges with comparative data for other floods at about 470 measurement points, and tables showing crest stages along an aggregate length of stream channel for 5,000 miles. The report also includes basic information in regard to the weather associated with the floods, results of detailed studies of the rainfall and run-off, analyses of the volume of flood waters'in the surface channel systems during the progress of the floods, and many other kinds of flood information. Following the main flood report is a brief report entitled "Flood" deposits of the Ohio River, January-February 1937, a study of sedimentation." An abstract of that report is presented on page 693.

Ohio River, Mississippi River↗
USGS2000

Primary food resources in the Sacramento-San Joaquin Delta

The Sacramento-San Joaquin River Delta, a complex mosaic of tidal freshwater habitats, is now a focus of ecosystem rehabilitation because of changes in critical functions associated with its geographic location at the landestuary interface. One of these functions is the production, transport, and transformation of organic matter that constitutes the “primary food supply,” that is, the food supply to the base of the food web. Interest in the primary food supply is motivated by evidence for sub-optimal food quantity or quality at trophic levels that support fish recruitment, including primary consumers such as clams, mysids, cladocerans, rotifers, and native copepods. We used the historical data set to examine the magnitudes of the most important organic matter sources for the Delta, the factors underlying their interannual and longer-term variability, and the implications of ecosystem rehabilitation actions for these sources. Here, we present a summary of the first phase of the analysis, including the quantitative importance of different organic matter sources and some of the hydrological controls on their year-to-year variability. The full report of this first phaseincluding data sources, the methods of calculation, and references, is in press elsewhere (Jassby and Cloern forthcoming). The historical data analysis is part of a larger project in which measurements of stable isotopes and biogeochemical markers, and experiments on organic matter biodegradation and zooplankton growth rates, are being used collectively to define the primary food resources and their quality.

California↗