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Sample records for pond dam study

  1. Seismic analysis of the Par Pond Dam: Study of slope failure and liquefaction. Technical evaluation report

    SciTech Connect

    Simos, N.; Reich, M.

    1994-07-01

    Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.

  2. 10. VIEW OF THE SEDIMENT DAM AND POND, FACING SOUTH. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW OF THE SEDIMENT DAM AND POND, FACING SOUTH. PHOTO TAKEN FROM WATER PUMP (FEATURE B-25). - Nevada Lucky Tiger Mill & Mine, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  3. Hydraulic and hydrologic evaluation of PAR Pond Dam. Technical evaluation report

    SciTech Connect

    Reich, M.; Wang, P.C.; Khanbilvardi, R.; Bezler, P.

    1993-10-01

    The PAR Pond Dam at Savannah River Plant was constructed in 1958--1959. Seepage, depressions, boils and spring flow were observed in varying locations on the dam in the last few years. Comprehensive geotechnical and hydraulic investigations pertaining to the effects of the above observations on the abilities of the dam to withstand future floods were made in 1991 and early 1993 where dam capacity to survive flooding and seismic events were evaluated. Brookhaven National Laboratory (BNL) was asked by the Department of Energy (EH) to carry out an independent review of the PAR Pond Dam response to future flooding and seismic events. This report addresses the studies made to evaluate the capacity of the dam to survive floods. A companion report will summarize the evaluations performed to assess the seismic capacity of the dam.

  4. Surface and subsurface soils at the Pond B dam: July 1998

    SciTech Connect

    Halverson, N.V.

    1999-12-03

    Pond B, 685-13G, is an inactive reactor cooling impoundment built in 1961 on the Savannah River Site (SRS). Between 1961 and 1964, Pond B received R-Reactor cooling water discharges that were contaminated with {sup 137}Cs, {sup 90}Sr and plutonium. Though the pond has not been used since 1964, radionuclides from the contaminated cooling water remain in the water and in the surface sediments of the pond. The current proposal to fix and repair the Pond B dam structure includes installing a new drain system and monitoring equipment. The dam will be reinforced with additional previous material on the downstream face of the dam. The objectives of this report are to describe the sampling methodology used during the July 1998 sampling event at the downstream face of the Pond B dam and in Pond B, present the results of the sampling event, and compare, where possible, these results to related risk-based standards.

  5. Estimation of Downstream Cesium Concentrations Following a Postulated PAR Pond Dam Break

    SciTech Connect

    Chen, K.F.

    2002-07-08

    Following a postulated PAR Pond dam break, some of the PAR Pond sediment including the cesium could be eroded and be transported downstream to the Savannah River through the Lower Three Runs Creek. Studies showed that most of the eroded sediment including the cesium would deposit in the Lower Three Runs Creek and the remainder would discharge to the Savannah River from the mouth of Lower Three Runs Creek. A WASP5 model was developed to simulate the eroded sediment and cesium transport from the Lower Three Runs Creek mouth to the Atlantic coast. The dissolved cesium concentrations at the Highway 301 bridge and near the City of Savannah Industrial and Domestic Water Supply Plant are 30 and 27 pCi/l, respectively. The concentrations at both locations are less than the U. S. Environmental Protection Agency drinking water standard of 200 pCi/l.

  6. 33 CFR 208.27 - Fort Cobb Dam and Reservoir, Pond (Cobb) Creek, Oklahoma.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (Cobb) Creek, Oklahoma. 208.27 Section 208.27 Navigation and Navigable Waters CORPS OF ENGINEERS..., Pond (Cobb) Creek, Oklahoma. The Bureau of Reclamation shall operate the Fort Cobb Dam and Reservoir in... Cobb, Oklahoma, river mile 5.0; a 19.0-foot stage (6,000 cfs) on the USGS gage on the Washita...

  7. 33 CFR 208.27 - Fort Cobb Dam and Reservoir, Pond (Cobb) Creek, Oklahoma.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (Cobb) Creek, Oklahoma. 208.27 Section 208.27 Navigation and Navigable Waters CORPS OF ENGINEERS..., Pond (Cobb) Creek, Oklahoma. The Bureau of Reclamation shall operate the Fort Cobb Dam and Reservoir in... Cobb, Oklahoma, river mile 5.0; a 19.0-foot stage (6,000 cfs) on the USGS gage on the Washita...

  8. 33 CFR 208.27 - Fort Cobb Dam and Reservoir, Pond (Cobb) Creek, Oklahoma.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (Cobb) Creek, Oklahoma. 208.27 Section 208.27 Navigation and Navigable Waters CORPS OF ENGINEERS..., Pond (Cobb) Creek, Oklahoma. The Bureau of Reclamation shall operate the Fort Cobb Dam and Reservoir in... Cobb, Oklahoma, river mile 5.0; a 19.0-foot stage (6,000 cfs) on the USGS gage on the Washita...

  9. 33 CFR 208.27 - Fort Cobb Dam and Reservoir, Pond (Cobb) Creek, Oklahoma.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (Cobb) Creek, Oklahoma. 208.27 Section 208.27 Navigation and Navigable Waters CORPS OF ENGINEERS..., Pond (Cobb) Creek, Oklahoma. The Bureau of Reclamation shall operate the Fort Cobb Dam and Reservoir in... Cobb, Oklahoma, river mile 5.0; a 19.0-foot stage (6,000 cfs) on the USGS gage on the Washita...

  10. 33 CFR 208.27 - Fort Cobb Dam and Reservoir, Pond (Cobb) Creek, Oklahoma.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (Cobb) Creek, Oklahoma. 208.27 Section 208.27 Navigation and Navigable Waters CORPS OF ENGINEERS..., Pond (Cobb) Creek, Oklahoma. The Bureau of Reclamation shall operate the Fort Cobb Dam and Reservoir in... Cobb, Oklahoma, river mile 5.0; a 19.0-foot stage (6,000 cfs) on the USGS gage on the Washita...

  11. WMOST v2 Case Study: Monponsett Ponds

    EPA Science Inventory

    This webinar presents an overview of the preliminary results of a case study application of EPA's Watershed Management Optimization Support Tool v2 (WMOST) for stakeholders in the Monponsett Ponds Watershed Workgroup. Monponsett Ponds is a large water system consisting of two ba...

  12. Environmental Assessment and Finding of No Significant Impact: Pond B Dam Repair Project at the Savannah River Site

    SciTech Connect

    N /A

    1999-09-27

    The Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-1285) for the proposed repair of the Pond B dam at the Savannah River Site (SRS), located near Aiken, South Carolina. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an environmental impact statement (EIS) is not required, and DOE is issuing this Finding of No Significant Impact (FONSI) and Floodplain Statement of Findings.

  13. CERCLA interim action at the Par Pond unit: A case study

    SciTech Connect

    Hickey, H.M.; Matthews, S.S.; Neal, L.W.; Weiss, W.R.

    1993-11-01

    The Par Pond unit designated under CERCLA consists of sediments within a Savannah River Site (SRS) cooling water reservoir. The sediments are contaminated with radionuclides and nonradioactive constituents from nuclear production reactor operations. The mercury in Par Pond is believed to have originated from the Savannah River. Because of Par Pond Dam safety Issues, the water level of the reservoir was drawn down, exposing more than 1300 acres of contaminated sediments and triggering the need for CERCLA interim remedial action. This paper presents the interim action approach taken with Par Pond as a case study. The approach considered the complexity of the Par Pond ecosystem, the large size of Par Pond, the volume of contaminated sediments, and the institutional controls existing at SRS. The Environmental Protection Agency (EPA) considers units with large volumes of low-concentration wastes, as is the case with Par Pond, to be {open_quotes}special sites.{close_quotes} Accordingly, EPA guidance establishes that the range of alternatives developed focus primarily on containment options and other remedial approaches that mitigate potential risks associated with the {open_quotes}special site.{close_quotes} The remedial alternatives, according to EPA, are not to be prohibitively expensive or difficult to implement. This case study also is representative of the types of issues that will need to be addressed within the Department of Energy (DOE) complex as nuclear facilities are transitioned to inactive status and corrective/remedial actions are warranted.

  14. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    NASA Astrophysics Data System (ADS)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  15. Evaporation Ponds or Recharge Structures ? the Role of Check Dams in Arkavathy River Basin, India

    NASA Astrophysics Data System (ADS)

    Jeremiah, K.; Srinivasan, V.; R, A.

    2014-12-01

    "Watershed development" has been the dominant paradigm for water management in India for the last two decades. Current spending on watershed development programmes rivals spending on large dams. In practice, watershed development involves a range of soil and water conservation measures including building check dams, gully plugs, contour bunds etc. Despite their dominance in water management paradigms, relatively little empirical data exists on these structures. Importantly, even though the benefits of individual watershed structures are recognized, the cumulative impact of building hundreds of such structures on hydrologic partitioning of a watershed remains unknown. We investigated the role of check dams in two small milli-watersheds in the Arkavathy River basin in South India. We conducted a comprehensive census of all check dams in the two milli-watersheds with a total area of 26 sq km. 40 check dams (representing a density of 1.35/sq km of watershed area) were geotagged, photographed, measured and their condition was recorded. We then selected twelve check dams and monitored the water stored using capacitance sensors. We also set up Automatic Weather Stations in each watershed. Inflows, evaporation and infiltration were calculated at each site to evaluate how check dams alter hydrologic partitioning in the watershed as a whole.

  16. Par Pond water balance

    SciTech Connect

    Hiergesell, R.A.; Dixon, K.L.

    1996-06-01

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs.

  17. Dam water quality study. Report to Congress

    SciTech Connect

    Not Available

    1989-05-01

    The objective of the report is to identify water quality effects attributable to the impoundment of water by dams as required by Section 524 of the Water Quality Act of 1987. The document presents a study of water quality effects associated with impoundments in the U.S.A.

  18. Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2014-12-01

    Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the

  19. Survey of Radionuclide Distributions Resulting from the Church Rock, New Mexico, Uranium Mill Tailings Pond Dam Failure

    SciTech Connect

    Weimer, W. C.; Kinnison, R. R.; Reeves, J. H.

    1981-12-01

    An intensive site survey and on-site analysis program were conducted to evaluate the distribution of four radionucliGes in the general vicinity of Gallup, New Mexico, subsequent to the accidental breach of a uranium mill tailings pond dam and the release of a large quantity of tailings pond materials. The objective of this work was to determine the distribution and concentration levels of {sup 210}Pb, {sup 226}Ra, {sup 230}Th, and {sup 238}U in the arroyo that is immediately adjacent to the uranium tailings pond (pipeline arroyo) and in the Rio Puerco arroyo into which the pipeline arroyo drains. An intensive survey between the United Nuclear Corporation (UNC) Church Rock Mill site and the New Mexico-Arizona state border was performed. Sampling locations were established at approximately 500-ft intervals along the arroyo. During the weeks of September 24 through October 5, 1979, a series of samples was collected from alternate sampling locations along the arroyo. The purpose of this collection of samples and their subsequent analysis was to provide an immediate evaluation of the extent and the levels of radioactive contamination. The data obtained from this extensive survey were then compared to action levels which had been proposed by the Nuclear Regulatory Commission and were adapted by the New Mexico Environmental Improvement Division (NMEID) for {sup 230}Th and {sup 226}Ra concentrations that would require site cleanup. The Pacific Northwest Laboratory/Nuclear Regulatory Commission mobile laboratory van was on-site at the UNC Church Rock Mill from September 22, 1979, through December 13, 1979, and was manned by one or more PNL personnel for all but four weeks of this time period. Approximately 1200 samples associated with the Rio Puerco survey were analyzed 1n the laboratory. An additional 1200 samples related to the Rio Puerco cleanup operations which the United Nuclear Corporation was conducting were analyzed on-site in the mobile laboratory. The purpose of

  20. MALLARD REPRODUCTIVE TESTING IN A POND ENVIRONMENT: A PRELIMINARY STUDY

    EPA Science Inventory

    A 2-year preliminary study was conducted on mallard ducks to determine the feasibility of using outdoor pond enclosures for reproductive studies and to evaluate the effects of the insecticide chlorpyrifos on mallard reproduction. No significant reproductive effects were observed ...

  1. Experimental study of the salt gradient solar pond stability

    SciTech Connect

    Karim, Choubani; Slim, Zitouni; Kais, Charfi; Jomaa, Safi Mohamed; Akbarzadeh, Aliakbar

    2010-01-15

    Many natural systems such as oceans, lakes, etc.., are influenced by the effect of double-diffusive convection. This phenomenon, which is a combination of heat and mass transfer, can destroy the stability of system-flows. In the case of solar ponds the middle layer, that is linearly stratified, acts as a thermal and mass insulator for the lower layer. This middle layer, called the Non-Convective Zone (NCZ), needs special care to avoid convection and to maintain its stability. In fact, due to an excess of heat stored, a thermal gradient occurs within the NCZ. A convective movement appears at the bottom of the stratified-layers and then grows to a double-diffusive convection movement. This movement transforms the stratified-layers into a well mixed layer, reducing the storage capacity of the pond. Laboratory small-scale pond and middle-scale outdoor solar ponds were designed and built to provide both quantitative data and to study the dynamic processes in solar ponds, including the behavior of the gradient zone. Particle Image Velocimetry (PIV) visualization-experiments carried out in the mechanical and energetic laboratory in the engineering school of Tunisia and experiments in the field showed that the instability of solar ponds could be limited by using porous media placed in the lower layer of the stratification. (author)

  2. Recent sediment studies refute Glen Canyon Dam hypothesis

    USGS Publications Warehouse

    Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

    2002-01-01

    Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

  3. Solar pond power plant feasibility study for Davis, California

    NASA Technical Reports Server (NTRS)

    Wu, Y. C.; Singer, M. J.; Marsh, H. E.; Harris, J.; Walton, A. L.

    1982-01-01

    The feasibility of constructing a solar pond power plant at Davis, California was studied. Site visits, weather data compilation, soil and water analyses, conceptual system design and analyses, a material and equipment market survey, conceptual site layout, and a preliminary cost estimate were studied. It was concluded that a solar pond power plant is technically feasible, but economically unattractive. The relatively small scale of the proposed plant and the high cost of importing salt resulted in a disproportionately high capital investment with respect to the annual energy production capacity of the plant. Cycle optimization and increased plant size would increase the economical attractiveness of the proposed concept.

  4. Migration of arsenic from old tailings ponds-A case study on the King Edward Mine, Cornwall, UK

    SciTech Connect

    Beeston, Michael Philip Tuen van Elteren, Johannes; Slejkovec, Zdenka; Glass, Hylke Jan

    2008-09-15

    A methodology is presented to study the physico-chemical processes in old tailings ponds using an array of analytical-physical chemistry approaches. A case study was conducted on the sorption/desorption behaviour of arsenic in tailings pond 2406, at the King Edward Mine (KEM) in Cornwall, UK. The tailings pond was in operation from approximately 1907 to 1921. The methodology involves two principal stages: (1) sequential extraction followed by subsequent arsenic species determination to characterise the material with regards to the association of arsenic with soil phases and identification of As (III/V) in the easily accessible soil phase; (2) batch contacting/equilibrating the tailings pond material with As(III/V), followed by a similar procedure as in stage 1 to establish the material's As(III/V) phase distribution kinetics/thermodynamics. By extrapolating the data from present day samples we infer past and future elemental mobility. From this study it is concluded that adsorption and desorption from tailings material is a rapid process for the most unstable soil phases (non-specific and specific) and a slow process for the more stable phases (poorly crystalline and well crystalline). The hypothetical application of this conclusion to the tailings from dam 2406 is that, during the initial phases of the dam's creation (ca. 100 years ago), when arsenic was both in solution and bound to mineralogical components, arsenic must have dispersed into the environment as a result of slow As(V) adsorption/phase distribution processes. Aging of the tailings material sees the movement of the arsenic to the more stable soil phases, producing a situation that is seen at present day.

  5. Development of a submersible shadowgraph for the study of interfaces in salt-gradient solar ponds

    SciTech Connect

    Huacuz, J.M.; Sierra, F.; Venegas, C.; Ramos, C. )

    1989-01-01

    In this paper the processes of development and testing of a submersible shadowgraph are described. This instrument was devised as a tool for the study of interfaces in salt-gradient solar ponds. Tests were carried out in the solar pond of the University of Texas at El Paso. Photographs of interfaces inside the pond were taken for the first time. The submersible shadowgraph can be stationed inside the pond for time dependent studies of a given region, or it can be used to scan the pond depth.

  6. The evolution of gravel bed channels after dam removal: Case study of the Anaconda and Union City Dam removals

    NASA Astrophysics Data System (ADS)

    Wildman, Laura A. S.; MacBroom, James G.

    2005-10-01

    The Anaconda and Union City Dams on the Naugatuck River in Connecticut were removed in February and October 1999. A detailed study of the sites prior to removal was undertaken including sediment testing and predictions of upstream channel formation post-dam removal. The 3.35-m-high timber crib/rock fill spillway of the Anaconda Dam partially breached during a storm prior to the dam's scheduled removal allowing a portion of the impounded sediment to move down through the river system. This event changed the removal plans and the remainder of the spillway was removed under an emergency order in the course of 4 days. The Union City Dam, a 2.44-m-high timber crib/rock fill dam capped with concrete and stone, was removed on schedule. A portion of the impounded sediment was removed by mechanical means during the deconstruction of the structure. The evolution of the two upstream channels post-project provided unique challenges and valuable insights as to what kind of channel transition can be expected in gravel bed river systems after a low head dam has been removed. This paper describes the initial engineering analysis and design, the subsequent removal of the two dams, and compares observations on the transition of the upstream channels following dam removal to the initial engineering predictions and other models. The relatively steep gravel bed channels evolved in a predictable manner, except where anthropogenic barriers (sanitary sewer, rock weir) interrupted.

  7. Turbidity study of solar ponds utilizing seawater as salt source

    SciTech Connect

    Li, Nan; Sun, Wence; Shi, Yufeng; Yin, Fang; Zhang, Caihong

    2010-02-15

    A series of experiments were conducted to study the turbidity reduction in solar ponds utilizing seawater as salt source. The experiment on the turbidity reduction efficiency with chemicals indicates that alum (KAl(SO{sub 4}){sub 2}.12H{sub 2}O) has a better turbidity control property because of its strongly flocculating and also well depressing the growing of algae and bacteria in the seawater. In comparison with bittern and seawater, our experiment shows that the residual brine after desalination can keep limpidity for a long time even without any chemical in it. Experiments were also conducted on the diffusion of turbidity and salinity, which show that the turbidity did not diffuse upwards in the solution. In the experiment on subsidence of soil in the bittern and saline with the same salinity, it was found that soil subsided quite quickly in the pure saline water, but very slowly in the bittern. In this paper we also proposed an economical method to protect the solar pond from the damage of rain. Finally, thermal performance of a solar pond was simulated in the conditions of different turbidities using a thermal diffusion model. (author)

  8. Natural or Simulated Ponds: An Environmental Baseline Study.

    ERIC Educational Resources Information Center

    Exline, Joseph D.

    1978-01-01

    Presents methods for analyzing soil and water samples in this classroom. Includes a classroom diagram, a listing of suggested materials, and the procedures for a classroom simulated pond. Relates classroom activities to work at a natural pond. (MA)

  9. Deformation Monitoring Studies and GPR Application on Dams

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2015-12-01

    Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Geometric changes at the dam surface and in the galleries are defined using geodetic methods. Physical and geometrical changes in embankment inside are defined using non-geodetic methods. This study provides information about the deformation monitoring techniques of the dams, dam safety and related analysis. The case study is the deformation monitoring of Atatürk Dam, 6th largest dam of world considering the reservoir volume, which was constructed on Euphrates (Fırat) River having importance for providing drinking water, hydroelectric power and irrigation. In the study, brief information is given about this dam and the methods of geodetic and non-geodetic deformation monitoring measurements applied by various disciplines. Bathymetric surveying techniques in the water covered area and Real Time Kinematic (RTK) GNSS surveying technique on the other area were used in order to determine the topography of the embankment and reservoir surfaces. Contour maps were drawn to determine the slumping and heaving areas. Also Ground

  10. Beaver Dam Effects on Gravel Transport Patterns - a Case Study

    NASA Astrophysics Data System (ADS)

    Bunte, K.; Swingle, K. W.; Potyondy, J. P.; Abt, S. R.

    2011-12-01

    Beaver dams are numerous in mountain streams, but little is known about gravel transport in those streams. The dams may be fully functioning and retain all incoming sediment or partially permeable to sediment or be almost completely removed. Beaver dams in their various states of preservation can have a profound influence on stream morphology and bedload transport. During the spring of 2011, the authors made a time series study of bedload transport in a mountain stream dominated by beavers dams. Dams occurred with a frequency of one every 50 feet and showed a range of decay and fluvial influence. Gravel transport was sampled with bedload traps over a 2-month long snowmelt highflow season. The reach-average gradient was 0.03 and stream widths ranged from 3 to 8 m. The stream bed was incised 0.5 to 1.5 m deep into a floodplain and typically trapezoidal in its cross-sectional shape. Much of the floodplain consisted of filled-in beaver dams. Partially breached dams that were permeable to gravel transport acted as an obstacle, forcing the flow around sharp bends. Complex hydraulic conditions developed in the vicinity of the bends with backwater eddies upstream and downstream of the remnant dam. Wake eddies at the downstream side of dam remnants caused gravel deposits. The tortuous channel course around the bends caused strong secondary currents that forced gravel transport into a narrow pathway along one of the banks causing a strong lateral concentration of transport. The pathway had a bed of fine and medium gravel, while the remainder of the bed consisted mostly of coarse gravel and cobbles that became immobile shortly after peak flows. Tracer experiments indicated that most of the mobile gravel traveled along that bankward path, even though flow velocities and depths were considerably smaller than in the stream center. Over the highflow season, flows increased to about 160% of the 1.5 year recurrence interval (Q1.5) within about a week and then remained within the

  11. Hydropower study. Blackwater Dam, Webster, New Hampshire. Reconnaissance report

    SciTech Connect

    Not Available

    1981-08-01

    The principal thrust of this limited reconnaissance effort is to determine whether any economically feasible hydropower development could be undertaken at Blackwater Dam. Baseline environmental, recreational, social and cultural conditions in the study area have been identified. Due to time and funding limitations only two alternatives were considered. If the study is continued several alternatives will be evaluated.

  12. Geodetic and Non-Geodetic Methods for Deformation Monitoring of Rock-Fill Dams, a Case Study at Ataturk DAM

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.

    2012-12-01

    Necessity to water is increasing day by day with respect to the World population, rising of living standards and destruction of nature. Water resources have to be controlled and supplied for agricultural uses, drinking and industrial purposes by the countries having limited water resources. This situation is also considerable for Turkey which has a location in the middle zone of World and having limited water sources. Dams are among the most important engineering structures which are used for these purposes. However, the functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Deformation measurements have an important status among various engineering surveying. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the horizontal and vertical small structural motions at regular intervals could be comprehended. Ataturk Dam in Turkey is the 6th largest dam of world considering the filling volume of embankment. Deformation of Ataturk Dam is being monitoring yearly since 2006 by Istanbul Technical University Department of Geomatics Engineering. We apply both GPS and conventional techniques. In this study, we present the result of radial deformations on Ataturk Dam between 2006 and 2010. The results show significant horizontal movements among the 72% of object points. Maximum movement is found as 14.12 cm (with a radial component of 14.08 cm) in 4.5 years.

  13. Uranium studies in the Tims Branch and Steed Pond system

    SciTech Connect

    Hayes, D.W.

    1984-11-01

    During the weekend of September 2--3, 1984, a part of the wooden spillway for Steed Pond gave way and the pond slowly drained. Consideration is being given to leaving Steed Pond dry. Steed Pond has accumulated some of the uranium discharged from 300 Area operations and past surveys have shown that the uranium concentration in the sediments ranges between 20 and 531 pCi/gm. The recently completed aerial survey of the exposed area of Steed Pond showed that the uranium was widely spread in the sediments of Steed Pond. Until ground cover is established over the exposed pond sediments, they will be subject to erosion. As much as 90 tons of sediment could be eroded from the exposed sediments in Steed Pond the first year, but the erosion could be reduced to 5--15 tons by establishing a ground cover such as rye grass. Only about 40% of the eroded sediment would be delivered to Upper Three Runs Creek, because most of the eroded sediment deposited before it reaches Upper Three Runs Creek. Less than 20 mCi of uranium would be transported downstream the first year from erosion of Steed Pond sediments, and this could be reduced to 2-- 5 mCi/year if ground cover is established.

  14. Water storage under changing climates: A case study of small farm dams in New Zealand

    NASA Astrophysics Data System (ADS)

    Thompson, J.; Preston, N.; Jackson, B. M.

    2009-12-01

    In many regions of the world, climate change scenarios predict a trend towards drier conditions. In agricultural areas, less rainfall during planting and growing periods will exacerbate existing water supply issues, with communities striving to find alternative water storage options. In New Zealand, both government and agricultural interest groups are promoting the construction of storage ponds (both small-scale ponds for farm use and larger reservoirs for community use) to tackle this issue. This paper investigates the use of small farm dams as a means of providing secure water storage while also considering downstream environmental impacts. New Zealand has thousands of small stock water and irrigation dams that interrupt streamflow, primarily located on first-order streams. With climate change scenarios predicting a 3-4% decrease in annual precipitation in some regions, it is expected that dam numbers will increase in the future. However, little is known about the impact of these dams on the downstream environment in terms of water quantity, quality, sediment transfer, and stream morphology at either the local or regional scale. A combination of field-based methods and modelling is used to quantify the overall impact of farm dams on the downstream system in an agricultural catchment in the Hawke’s Bay region of New Zealand. Results show that farm dams reduce overall discharge and flood peaks, but sustain winter flows for a longer duration between rainfall events. The dams also create a lowering of water quality and a decrease in the transfer of sediment, with aggradation occurring in downstream channel reaches. Implications at the wider catchment scale are discussed, along with improved management practices which could allow for both water security and the protection of the environment. Results have implications for regions of the world which face drier conditions under changing climate regimes and need environmentally and socio-economically sustainable water

  15. Dam located to east of powerhouse, view from south. This ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Dam located to east of powerhouse, view from south. This dam holds back the waters of the Chattahoochee River to form the mill pond north of Riverdale Cotton Mill - Riverdale Cotton Mill, Powerhouse & Dam, Valley, Chambers County, AL

  16. 8. VIEW OF DAM 83, SHOWING OLD SOURIS RIVER CHANNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF DAM 83, SHOWING OLD SOURIS RIVER CHANNEL FROM THE DOWNSTREAM FACE OF THE DAM WITH POND A IN THE BACKGROUND, LOOKING SOUTH - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  17. Thermal storage case study: Combined building mass and cooling pond

    SciTech Connect

    Arnold, D.

    2000-07-01

    In 1994 a large U.K. credit card company decided to relocate and centralize its offices and operations from a number of city center sites to the outskirts on a green field site. The company decided that the concept for the new building should be environmentally friendly, i.e., naturally ventilated and cooled by openable windows. However, during initial studies there was concern over whether natural cooling and ventilation alone would be adequate to maintain thermal comfort during hot weather. The design solution was to provide a mix of passive and mechanical systems that could be switched in response to internal conditions and the prevailing weather. The object was to use passive features, i.e., the building thermal mass and storage and cooling effects of a pond, to maintain thermal comfort whenever possible and only switch to mechanical cooling under extreme conditions. The building was occupied progressively during the spring of 1997. The case study covers the period from the initial design concept to the end of the first 18 months of occupation.

  18. Swan Lake Dam: a study in cost saving

    SciTech Connect

    Not Available

    1985-04-01

    The construction of the dam for the Swan Lake hydroelectric project in Alaska is discussed. The hydro project was built for an estimated $4.3 million less than conventional hydro dams of this scope. The project highlights are given.

  19. Par Pond phytoplankton in association with refilling of the pond: Final Report for sampling from February 1995 -- September 1996

    SciTech Connect

    Wilde, E.W.; Johnson, M.A.; Cody, W.C.

    1996-12-31

    This report describes the results of phytoplankton analyses from Par Pond samples collected between February 1995 and September 1996. The principal objective of the study was to determine the effect of refilling of Par Pond following repair of the dam on the phytoplankton community. Algal blooms are often responsible for fish kills and other detrimental effects in ponds and lakes, and it was postulated that decaying vegetation from formerly exposed sediments might trigger algal blooms that could result in fish kills in Par Pond following the refill. Sporadic algal blooms involving blue-green algae were detected, especially during the summer of 1996. However, the data derived from the study demonstrates that overall, the refilling effort caused no significant negative impact to the pond attributable to phytoplankton dynamics.

  20. A comparative study of the growth of Tetraselmis sp. in large scale fixed depth and decreasing depth raceway ponds.

    PubMed

    Das, Probir; Thaher, Mahmoud Ibrahim; Hakim, Mohammed Abdul Quadir Mohd Abdul; Al-Jabri, Hareb Mohammed S J; Alghasal, Ghamza Saed H S

    2016-09-01

    In this study, an alternative approach was proposed where excess seawater would be added only during inoculation (DD) rather than daily addition (FD). Growth and metabolite contents of Tetraselmis sp. weren't affected for daily increase of 2% NaCl salinity. Tetraselmis sp. was then cultured in DD and FD pond. In DD pond, initial culture depth was 23.5cm and its depth reduced as no water was added; for FD pond, everyday sterilized seawater was added to maintain 20cm depth. DD pond had higher biomass productivity compared to FD pond, until DD pond was deeper than FD pond; metabolite content and FAME profile of Tetraselmis sp. were also similar in both cultures. Therefore, considering the simplicity in operation, halo tolerant microalgae can be grown in DD pond method. PMID:27235973

  1. Nonlinear Seismic Analysis of Morrow Point Dam: A Study for the United States Bureau of Reclamation

    SciTech Connect

    Noble, C R; Solberg, J

    2004-02-20

    This research and development project was sponsored by the United States Bureau of Reclamation (USBR), who are best known for the dams, power plants, and canals it constructed in the 17 western states. The mission statement of the USBR's Dam Safety Office, located in Denver, Colorado, is ''to ensure Reclamation dams do not present unacceptable risk to people, property, and the environment.'' The Dam Safety Office does this by quickly identifying the dams which pose an increased threat to the public, and quickly completing the related analyses in order to make decisions that will safeguard the public and associated resources. The research study described in this report constitutes one element of USBR's research and development work to advance their computational and analysis capabilities for studying the response of dams to strong earthquake motions. This project focused on the seismic response of Morrow Point Dam, which is located 263 km southwest of Denver, Colorado.

  2. Valuating Ecosystem Services of Urban Ponds - case study from Bangladesh

    NASA Astrophysics Data System (ADS)

    Carle, Nina

    2016-04-01

    A climate risk assessment for the city of Barisal was carried out by a consultancy firm, financed by KfW Development Bank of Germany. Due to high dependencies on natural capital of people in developing countries they are facing high vulnerability when it comes to changes of the asset category 'natural capital' (here: urban ponds), whether due to the exposition on climate (change) related impacts, implemented measures or land use change. With a closer view on the city's assets, the question remained open to the author 1) Under current conditions, what is the demand for ecosystem services (ES) 2) What is the value of the benefits and the how much is the contribution to the city's welfare? 3) What are the future changes in the demand for ES? And what are the future changes on the supply side (pressures and threats to the ecosystem)? Methodology: The City of Barisal in Bangladesh has a calculated number of around 10.000 urban rain-fed ponds,representing 6.5% of the city area, which represents a huge natural water supply and gives the city its characteristic face. In August 2015 a user survey was conducted in the city of Barisal, in every ward (administrative unit), to determine the demand for ecosystem services related to urban ponds, evaluating over 600 ponds. The findings will present the huge variation of provisioning ecosystem services and an important regulating service, related to economic and domestic use, in a spatial resolution. It will be shown, how the importance of ES changes, by changing the unit of analysis (families or ponds or the city) and the importance for the livelihood of pond owners and users. A relationship between pond area(m2) and number of users was detected, also the role of compensation payments for the pond owners by the users. It will be shown how natural capital, privately and publicly owned,contributes in an important way in buffering unequal distribution of societies resources in the short- and long-run. However society's demand for ES

  3. Why Does Amphibian Chytrid (Batrachochytrium dendrobatidis) Not Occur Everywhere? An Exploratory Study in Missouri Ponds

    PubMed Central

    Strauss, Alex; Smith, Kevin G.

    2013-01-01

    The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is a globally emerging pathogen that has caused widespread amphibian population declines, extirpations, and extinctions. However, Bd does not occur in all apparently suitable amphibian populations, even within regions where it is widespread, and it is often unclear why Bd occurs in some habitats but not others. In this study, we rigorously surveyed the amphibian and invertebrate biodiversity of 29 ponds in Missouri, screened resident amphibian larvae (Rana (Lithobates) sp.) for Bd infection, and characterized the aquatic physiochemical environment of each pond (temperature pH, conductivity, nitrogen, phosphorus, and chlorophyll-a). Our goal was to generate hypotheses toward answering the question, “Why does Bd not occur in all apparently suitable habitats?” Bd occurred in assayed amphibians in 11 of the 29 ponds in our study area (38% of ponds). We found no significant relationship between any single biotic or abiotic variable and presence of Bd. However, multivariate analyses (nonmetric multidimensional scaling and permutational tests of dispersion) revealed that ponds in which Bd occurred were a restricted subset of all ponds in terms of amphibian community structure, macroinvertebrate community structure, and pond physiochemistry. In other words, Bd ponds from 6 different conservation areas were more similar to each other than would be expected based on chance. The results of a structural equation model suggest that patterns in the occurrence of Bd among ponds are primarily attributable to variation in macroinvertebrate community structure. When combined with recent results showing that Bd can infect invertebrates as well as amphibians, we suggest that additional research should focus on the role played by non-amphibian biota in determining the presence, prevalence, and pathogenicity of Bd in amphibian populations. PMID:24086681

  4. Physical model studies of cooling pond water quality

    SciTech Connect

    Frediani, H.A. Jr.; Ondler, W.C.; Palmer, P.K.

    1995-12-31

    Under the Florida Electrical Power Plant Siting Act, Florida Power & Light Company (FPL) licensed their Martin Site for a total ultimate capacity of 3200 megawatts, When the ultimate capacity is installed, the heat dissipated from the Martin 6500 acre closed cycle cooling pond will cause so much evaporation that the pond`s dissolved solids will be hydraulically concentrated (about 3.5 times that of the makeup water added to it to replace that evaporation). Because water quality-based effluent limits are relatively low (often lower than detection limits), the conservative assumption, that undetected constituents were present at 99% of the detection limit, led to simple mass balance estimates that such constituents would be concentrated so as to exceed limits,even though some of the constituents were never detected in the makeup water. Mathematical metal specification modeling predicted reduction in concentrations due to precipitation and/or sorption only for some constituents. Because of the chain of conservative assumptions required for that modeling, FPL decided to attempt a physical simulation of the concentration effect of the cooling pond.

  5. Periphytonic diversity in Bhagirathi: preimpoundment study of Tehri dam reservoir.

    PubMed

    Sharma, Ramesh C; Bahuguna, Manju; Chauhan, Punam

    2008-10-01

    Tehri hydroelectric project of 2,400 MW capacity, the Asia's highest dam constructed on the Bhagirathi river in Uttarakhand is one of the most debatable dams of the country. The fluvial system of Bhagirathi and Bhilagana has been converted into a huge lentic water reservoir of 2.62x10(9) m3 capacity. Therefore, the information on periphytonic diversity before impoundment is very important. The preimpoundment study over one year (September 2004 - August 2005) was carried out monthly to analyse the periphytonic diversity in a lotic environment of Bhagirathi, one of the parent streams of Ganges. Periphytons are the important primary producers of metarhithronic stretch of Bhagirathi. 40 taxa of periphytons, represented by the families of Bacillariophyceae (25 taxa), Chlorophyceae (11 taxa) and Myxophyceae (4 taxa), were recorded from the Bhagirathi river before impoundment. The Shannon-Weiner diversity index ranged between 3.404 to 4.360 for periphytons, which indicates a good health of the ecosystem. The present study revealed that the combined impact of velocity of the water, hydromedian depth (HMD), turbidity, dissolved oxygen, total dissolved solids (TDS), and water temperature influenced the diversity of periphytons dwelling Bhagirathi. PMID:19697759

  6. 216-U-10 Pond and 216-Z-19 Ditch characterization studies

    SciTech Connect

    Last, G.V.; Duncan, D.W.; Graham, M.J.; Hall, M.D.; Hall, V.W.; Landeen, D.S.; Leitz, J.G.; Mitchell, R.M.

    1994-02-01

    The chemical, reprocessing of spent nuclear fuels at the US Department of Energy`s Hanford Site has generated large volumes of radioactive liquid effluents. The majority of these effluents have been used strictly for cooling or other supportive functions and have been discharged to ditches and ponds. The 216-U-10 Pond and 216-Z-19 Ditch are two such disposal facilities. These facilities are components of an integrated system of ditches, ponds, and overflow facilities collectively referred to as the U-Pond disposal system. The U-Pond system has been used since 1943 and has received a large variety of radioisotopes from several sources. This study covered tho major aspects of the environment, including wind resuspension, biological uptake and transport, geologic distribution in surface and subsurface sediments, and ground-water impacts. The long-term use of U-Pond and the Z-19 Ditch has resulted in the localized accumulation of transuranic and fission product inventories as a result of sorption and filtration of particulates onto the uppermost sediments.

  7. Floods from tailings dam failures.

    PubMed

    Rico, M; Benito, G; Díez-Herrero, A

    2008-06-15

    This paper compiles the available information on historic tailings dam failures with the purpose to establish simple correlations between tailings ponds geometric parameters (e.g., dam height, tailings volume) and the hydraulic characteristics of floods resulting from released tailings. Following the collapse of a mining waste dam, only a part of tailings and polluted water stored at the dam is released, and this outflow volume is difficult to estimate prior the incident. In this study, tailings' volume stored at the time of failure was shown to have a good correlation (r2=0.86) with the tailings outflow volume, and the volume of spilled tailings was correlated with its run-out distance (r2=0.57). An envelope curve was drawn encompassing the majority of data points indicating the potential maximum downstream distance affected by a tailings' spill. The application of the described regression equations for prediction purposes needs to be treated with caution and with support of on-site measurement and observations. However, they may provide a universal baseline approximation on tailing outflow characteristics (even if detailed dam information is unavailable), which is of a great importance for risk analysis purposes. PMID:18096316

  8. Dam Removal Information Portal (DRIP)—A map-based resource linking scientific studies and associated geospatial information about dam removals

    USGS Publications Warehouse

    Duda, Jeffrey J.; Wieferich, Daniel J.; Bristol, R. Sky; Bellmore, J. Ryan; Hutchison, Vivian B.; Vittum, Katherine M.; Craig, Laura; Warrick, Jonathan A.

    2016-01-01

    The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history of river management, science is just beginning to guide our understanding of the physical and ecological implications of dam removal. Ultimately, the “lessons learned” from previous scientific studies on the outcomes dam removal could inform future scientific understanding of ecosystem outcomes, as well as aid in decision-making by stakeholders. We created a database visualization tool, the Dam Removal Information Portal (DRIP), to display map-based, interactive information about the scientific studies associated with dam removals. Serving both as a bibliographic source as well as a link to other existing databases like the National Hydrography Dataset, the derived National Dam Removal Science Database serves as the foundation for a Web-based application that synthesizes the existing scientific studies associated with dam removals. Thus, using the DRIP application, users can explore information about completed dam removal projects (for example, their location, height, and date removed), as well as discover sources and details of associated of scientific studies. As such, DRIP is intended to be a dynamic collection of scientific information related to dams that have been removed in the United States and elsewhere. This report describes the architecture and concepts of this “metaknowledge” database and the DRIP visualization tool.

  9. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    USGS Publications Warehouse

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  10. Relative performance of duckweed ponds and rock filtration as advanced in-pond wastewater treatment processes for upgrading waste stabilisation pond effluent: a pilot study.

    PubMed

    Short, M D; Cromar, N J; Nixon, J B; Fallowfield, H J

    2007-01-01

    An experimental pilot plant was operated over a five month period to assess the relative treatment performances of: a duckweed (DW) pond; a rock filter (RF); and an open pond (OP); for the upgrading of final WSP effluent prior to reuse applications. Each pilot treatment system consisted of three identical ponds arranged in three parallel series, each fed a continuous flow of wastewater from the local Bolivar treatment plant. Light penetration profiling for the DW and OP systems revealed some 55% greater light attenuation capacity for DW ponds compared to the OP system. Results showed a significantly elevated performance capacity for the RF treatment with respect to BOD5, SS, turbidity and NH4-N removal, but equal treatment performances for algal (chlorophyll) removal. No significant performance differences were evident between the DW and OP treatments for any of the monitored parameters. Soluble reactive phosphorus, faecal coliform and E. coli removals were similar for all pilot treatment systems. Rock filters not only demonstrated an enhanced performance capacity in terms of removal of loaded parameters, but also showed greater reliability of performance and produced a consistently higher quality final effluent. Rock filters demonstrated greater potential over both DW and OP systems for the upgrading of WSP effluent prior to reuse application. PMID:17591203

  11. Water-quality study of proposed reregulation dam downstream of Wolf Creek Dam, Cumberland River, Kentucky. Final report

    SciTech Connect

    Martin, J.L.

    1986-03-01

    This report describes the application of an unsteady, one-dimensional water-quality model to the Cumberland River below Wolf Creek Dam, Kentucky. A hydropower upgrade of Wolf Creek Dam and construction of a reregulation dam, located approximately 10 miles below Wolf Creek Dam, are under consideration. Simulations were conducted under unreregulated conditions and projected conditions following impoundment to provide information concerning the effect of the reregulation dam on water quality in the Cumberland River. Under the conditions simulated, the reregulation dam was predicted to have little impact on temporally averaged water temperatures or dissolved-oxygen concentrations. Temporal variations in water temperatures were retarded under reregulation conditions.

  12. Holocene beaver damming, fluvial geomorphology, and climate in Yellowstone National Park, Wyoming

    NASA Astrophysics Data System (ADS)

    Persico, Lyman; Meyer, Grant

    2009-05-01

    We use beaver-pond deposits and geomorphic characteristics of small streams to assess long-term effects of beavers and climate change on Holocene fluvial activity in northern Yellowstone National Park. Although beaver damming has been considered a viable mechanism for major aggradation of mountain stream valleys, this has not been previously tested with stratigraphic and geochronologic data. Thirty-nine radiocarbon ages on beaver-pond deposits fall primarily within the last 4000 yr, but gaps in dated beaver occupation from ~ 2200-1800 and 950-750 cal yr BP correspond with severe droughts that likely caused low to ephemeral discharges in smaller streams, as in modern severe drought. Maximum channel gradient for reaches with Holocene beaver-pond deposits decreases with increasing basin area, implying that stream power limits beaver damming and pond sediment preservation. In northern Yellowstone, the patchy distribution and cumulative thickness of mostly < 2 m of beaver-pond deposits indicate that net aggradation forced by beaver damming is small, but beaver-enhanced aggradation in some glacial scour depressions is greater. Although 20th-century beaver loss and dam abandonment caused significant local channel incision, most downcutting along alluvial reaches of the study streams is unrelated to beaver dam abandonment or predates historic beaver extirpation.

  13. 75 FR 7469 - Whitman River Dam, Inc.; Notice of Intent To File License Application, Filing of Pre-Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-19

    ...: Whitman River Dam, Inc. e. Name of Project: Crocker Pond Project. f. Location: The project would be located at the existing Crocker Pond Dam, on the Whitman River, in Worcester County, Massachusetts....

  14. Salton Sea Solar Pond Power Plant Design Study and Regional Applicability

    NASA Technical Reports Server (NTRS)

    French, R. L.

    1984-01-01

    Ormat collected and organized the data base and conducted conceptual plant design, performance, and cost analysis. JPL conducted site-specific studies related to solar pond chemistry, soil biological activity, and dike design and construction. WESTEC conducted environmental investigation studies and performed an environmental assessment. SCE provided planning support for licensing and permitting and technical evaluations of the system design and cost estimate.

  15. Biomarkers of aging and falling: the Beaver Dam eye study

    PubMed Central

    Knudtson, Michael D.; Klein, Barbara E. K.; Klein, Ronald

    2009-01-01

    Falls are an important cause of morbidity in older adults and are an important source of health care spending. We hypothesize that falls are associated with systemic biomarkers of aging. The following functions, measured at the 1998–2000 and 2003–05 examinations of the Beaver Dam Eye study, were considered to be biomarkers of aging (frailties): poorer visual acuity, contrast sensitivity or discrepant vision between the eyes, inability to rise from a chair, slower gait time, poorer hand grip strength, and lower peak expiratory flow rate. We found that poorer values on biomarkers of aging (frailties) at the 1998–2000 examination were associated with 2 or more reported falls in the past year at the 2003–05 examination (p < 0.05 for all markers except peak expiratory flow rate). When the markers were combined as an index of biological aging (frailty), the index was significantly associated with falls after controlling for significant confounders (odds ratio per 1 step increase in the index: 1.33; 95% confidence interval = CI = 1.13–1.57) We conclude that biomarkers of aging, including any of three measures of visual function, are associated with falls. Improvement in these functional measures may lead to decreased risk of falls. PMID:18513808

  16. Environmentally safe design of tailing dams for the management of iron ore tailings in Indian context.

    PubMed

    Ghose, Mrinal K; Sen, P K

    2005-10-01

    The need for the disposal of iron ore tailings in an enviornmentally firiendly manner is of great concern. This paper investigates the soil engineering properties for the construction of iron ore tailing dam, its foundation, construction materials and design data used for the construction analysis of the tailing dam. Geophysical investigations were carried out to establish the bedrock below the spillway. A computer programme taking into account the Swedish Slip Circle Method of analysis was used in the stability analysis of dam. It also focuses on the charactierstics of the tailings reponsible for the determination of optimum size of tailing pond for the containment of the tailings. The studies on the settling characteristics of tailings indicate much less area in comparison to the area provided in the existing tailing ponds in India. In the proposed scheme, it is suggested to provide an additional unit of sedimentation tank before the disposal of tailings to the tailing pond. PMID:17051916

  17. Southwest region solar pond study for three sites: Tularosa Basin, Malaga Bend, and Canadian River

    SciTech Connect

    Boegli, W.J.; Dahl, M.M.; Remmers, H.E.

    1984-08-01

    In the study, the Bureau of Reclamation investigated the technical and economic feasibility of using solar salt-gradient ponds to generate power and to produce freshwater in Bureau projects at three sites--the Canadian River at Logan, New Mexico; Malaga Bend on the Pecos River near Carlsbad, New Mexico; and the Tularosa Basin in the vicinity of Alamogordo, New Mexico. The ponds would be used to generate electric power that could be integrated with the Bureau's power grid or used in combination with thermal energy from the ponds to power commercially available desalination systems to produce freshwater. Results of the economic analysis, which concentrated primarily on the Tularosa Basin site, showed that solar-pond-generated intermediate load power would cost between 62 and 90 mills/kWh and between 52 and 83 mills/kWh for baseload power. This results in benefit-cost ratios of approximately 2.0 and 1.3 for intermediate and baseload, respectively, when compared to similar facilities powered by fossil fuels. The cost savings are even more pronounced when comparing the two (solar versus fossil fuel) as a source of power for conventional distillation and membrane-type desalination systems.

  18. The Dalles Dam, Columbia River: Spillway Improvement CFD Study

    SciTech Connect

    Cook, Chris B.; Richmond, Marshall C.; Serkowski, John A.

    2006-06-01

    This report documents development of computational fluid dynamics (CFD) models that were applied to The Dalles spillway for the US Army Corps of Engineers, Portland District. The models have been successfully validated against physical models and prototype data, and are suitable to support biological research and operations management. The CFD models have been proven to provide reliable information in the turbulent high-velocity flow field downstream of the spillway face that is typically difficult to monitor in the prototype. In addition, CFD data provides hydraulic information throughout the solution domain that can be easily extracted from archived simulations for later use if necessary. This project is part of an ongoing program at the Portland District to improve spillway survival conditions for juvenile salmon at The Dalles. Biological data collected at The Dalles spillway have shown that for the original spillway configuration juvenile salmon passage survival is lower than desired. Therefore, the Portland District is seeking to identify operational and/or structural changes that might be implemented to improve fish passage survival. Pacific Northwest National Laboratory (PNNL) went through a sequence of steps to develop a CFD model of The Dalles spillway and tailrace. The first step was to identify a preferred CFD modeling package. In the case of The Dalles spillway, Flow-3D was as selected because of its ability to simulate the turbulent free-surface flows that occur downstream of each spilling bay. The second step in development of The Dalles CFD model was to assemble bathymetric datasets and structural drawings sufficient to describe the dam (powerhouse, non-overflow dam, spillway, fish ladder entrances, etc.) and tailrace. These datasets are documented in this report as are various 3-D graphical representations of The Dalles spillway and tailrace. The performance of the CFD model was then validated for several cases as the third step. The validated model

  19. Cooling ponds/lakes and fish

    SciTech Connect

    Monzingo, R.G.; Hughes, J.H.

    1980-01-01

    The discussions concern both cooling ponds and cooling lakes. By regulatory definition, cooling ponds, also called perched ponds, are constructed by building dikes and pumping water, usually from a nearby river, into the diked area. Cooling lakes on the other hand, are created by damming a stream or streams, thereby producing impoundments. The paper begins the discussion with a more detailed examination of the problem at the Collins Station.

  20. Beaver ponds' impact on fluvial processes (Beskid Niski Mts., SE Poland).

    PubMed

    Giriat, Dorota; Gorczyca, Elżbieta; Sobucki, Mateusz

    2016-02-15

    Beaver (Castor sp.) can change the riverine environment through dam-building and other activities. The European beaver (Castor fiber) was extirpated in Poland by the nineteenth century, but populations are again present as a result of reintroductions that began in 1974. The goal of this paper is to assess the impact of beaver activity on montane fluvial system development by identifying and analysing changes in channel and valley morphology following expansion of beaver into a 7.5 km-long headwater reach of the upper Wisłoka River in southeast Poland. We document the distribution of beaver in the reach, the change in river profile, sedimentation type and storage in beaver ponds, and assess how beaver dams and ponds have altered channel and valley bottom morphology. The upper Wisłoka River fluvial system underwent a series of anthropogenic disturbances during the last few centuries. The rapid spread of C. fiber in the upper Wisłoka River valley was promoted by the valley's morphology, including a low-gradient channel and silty-sand deposits in the valley bottom. At the time of our survey (2011), beaver ponds occupied 17% of the length of the study reach channel. Two types of beaver dams were noted: in-channel dams and valley-wide dams. The primary effect of dams, investigated in an intensively studied 300-m long subreach (Radocyna Pond), was a change in the longitudinal profile from smooth to stepped, a local reduction of the water surface slope, and an increase in the variability of both the thalweg profile and surface water depths. We estimate the current rate of sedimentation in beaver ponds to be about 14 cm per year. A three-stage scheme of fluvial processes in the longitudinal and transverse profile of the river channel is proposed. C. fiber reintroduction may be considered as another important stage of the upper Wisłoka fluvial system development. PMID:26657380

  1. Brief reconnaissance study for the addition of hydropower for Carr Fork Dam, Sassafras, Kentucky

    SciTech Connect

    Gebhard, T.G. Jr.

    1982-05-24

    The feasibility of retrofitting the Carr Fork Dam near Hazard, KY for power generation was examined. This dam has a developable head of 80 ft and was built in 1975 to provide flood protection. The study of environmental, institutional, safety, and economic factors showed that the total investment cost would be $909,600 and that hydroelectric power development at this site is not feasible unless a higher price could be obtained for the power sold. (LCL)

  2. Brief reconnaissance study for the addition of hydropower for Riegel Dam, Trion, Georgia

    SciTech Connect

    Gebhard, T.G. Jr.

    1982-05-10

    The feasibility of retrofitting the Riegel Dam near Trion, Georgia for power generation was examined. This dam has a developable head of 17 ft., was built in 1900 for supplying hydroelectric power for a textile mill, and currently provides cooling water to the mill. The study of environmental, institutional, safety and economic factors showed that hydroelectric power development at this site would require new generating equipment and that such retrofitting appears to be economically feasible. (LCL)

  3. Dam safety: Morris Sheppard Dam rehabilitation

    SciTech Connect

    Garland, J.D.; Waters, R.H.; Focht, J.A. Jr.

    1995-12-31

    Morris Sheppard Dam is one of the world`s largest flat slab buttress dams. It is located on the Brazos River about 96 km (60 miles) west of Dallas - Fort Worth. Designed by Ambursen Dam Company, the dam was constructed between 1938 and 1941 at a cost of $8.7 million. In 1987, a maximum buttress movement of 114 mm (4.5 inches) was discovered. The dam was successfully rehabilitated between 1987 and 1994 at a cost of $36 million. This paper will describe: (1) the dam`s construction and operational history, (2) the lowering of the reservoir by 3.94 m (13 feet) as an emergency response when the movement was discovered, (3) the initial stabilization of the dam by the addition of relief wells and grouting, (4) the final stabilization using ballast to increase the weight of the dam, (5) the use of actual dam performance as a full-scale, long-term, load test to back-calculate realistic strength parameters, (6) the multiple sets of design stability criteria used to analyze the structure, and (7) the use of model studies to enlarge the dam`s stilling basin and design an emergency spillway to handle the PMF.

  4. Par Pond vegetation status 1996

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned.

  5. Solar ponds

    SciTech Connect

    Jayadev, T.S.; Edesess, M.

    1980-04-01

    This report first describes the different types of solar ponds including the nonconvecting salt gradient pond and various saltless pond designs. It then discusses the availability and cost of salts for salt gradient ponds, and compares the economics of salty and saltless ponds as a function of salt cost. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirements is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future.

  6. Freshwater ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter summarizes aquaculture pond ecology. The underlying theme is how ponds supply essential life-support functions (food, oxygen, and waste treatment) and how those functions are subsidized by external resources as culture intensity increases. Ponds are confined bodies of standing wate...

  7. Visibility from Roads Predict the Distribution of Invasive Fishes in Agricultural Ponds

    PubMed Central

    Kizuka, Toshikazu; Akasaka, Munemitsu; Kadoya, Taku; Takamura, Noriko

    2014-01-01

    Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that

  8. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    PubMed Central

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-01-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  9. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China.

    PubMed

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-12-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the "source-pathway-target" in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  10. Synthesis of Juvenile Salmonid Passage Studies at The Dalles Dam, Volume II, 2001-05

    SciTech Connect

    Johnson, Gary E.; Beeman, John W.; Duran, Ian; Puls, Andrew

    2007-08-15

    The overall goal of juvenile salmonid research at The Dalles Dam is to provide data to inform decisions on strategies to improve smolt survival rates at the project. Survival improvement strategies address the three primary passage routes at The Dalles Dam -- spillway, sluiceway, and turbines – with the general intent to increase spill and sluice passage and decrease turbine passage. Since the review by Ploskey et al. (2001a) of research during 1982-2000 at The Dalles Dam, the Corps funded over $20M of research in at least 39 studies during 2001-2006. The purpose of the current review is to synthesize juvenile salmonid passage data at The Dalles Dam (TDA) collected from 2001 through 2006. The data we synthesize comes from numerous research techniques employed to address particular study objectives at The Dalles Dam. The suite of techniques includes acoustic and radio telemetry, acoustic cameras, acoustic Doppler current profilers, balloon tags, computational fluid dynamics models, drogues, fixed and mobile hydroacoustics, fyke nets, physical scale models, PIT-tags, sensor fish, sonar trackers, and underwater video. Hydraulic data involves flow patterns and water velocities. Biological data involve forebay approach paths and residence times, horizontal and diel distributions, passage efficiencies and effectiveness, fish behaviors, tailrace egress and predation rates, and route-specific and total project survival rates. Data for 2001-2006 are synthesized in this report to provide, in conjunction with Ploskey et al. (2001a), resources for engineers, biologists, and dam operators to use when making decisions about fish protection measures for juvenile salmonids at The Dalles Dam. This review covers the major fish passage research efforts during 2001-2006 and includes sections on the Environmental Setting, Forebay and Project Passage Studies, Spill Studies, Sluiceway Studies, Turbine Studies, Smolt Survival Studies, and a Discussion.

  11. Solar ponds

    SciTech Connect

    Jayadev, T.S.; Edesess, M.

    1980-04-01

    The different types of solar ponds are described, including the nonconvecting salt gradient pond and various saltless pond designs. Then the availability and cost of salts for salt gradient ponds are discussed and costs are compared. A simple computational model is developed to approximate solar pond performance. This model is later used to size solar ponds for district heating and industrial process heat applications. For district heating, ponds are sized to provide space conditioning for a group of homes, in different regions of the United States. Size requirement is on the order of one acre for a group of 25 to 50 homes. An economic analysis is performed of solar ponds used in two industrial process heat applications. The analysis finds that solar ponds are competitive when conventional heat sources are priced at $5 per million Btu and expected to rise in price at a rate of 10% per year. The application of solar ponds to the generation of electricity is also discussed. Total solar pond potential for displacing conventional energy sources is estimated in the range of from one to six quadrillion Btu per year in the near and intermediate future.

  12. 27. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. View of dam structures - wing walls, overflow shute to right, camera in middle of flume intake from pond. North/northeast 40 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  13. DAM Safety and Deformation Monitoring in Dams

    NASA Astrophysics Data System (ADS)

    Kalkan, Y.; Bilgi, S.; Potts, L.; Miiama, J.; Mahgoub, M.; Rahman, S.

    2013-12-01

    Water is the life and necessity to water is increasing day by day with respect to the World population, rising of living standards and destruction of nature. Thus, the importance of water and water structures have been increasing gradually. Dams are among the most important engineering structures used for water supplies, flood controls, agricultural purposes as well as drinking and hydroelectric power. There are about 150.000 large size dams in the World. Especially after the Second World War, higher and larger capacity dams have been constructed. Dams create certain risks like the other manmade structures. No one knows precisely how many dam failures have occurred in the World, whereas hundreds of dam failures have occurred throughout the U.S. history. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some information, safety and the techniques about the deformation monitoring of the

  14. Investigation on trophic state index by artificial neural networks (case study: Dez Dam of Iran)

    NASA Astrophysics Data System (ADS)

    Saghi, H.; Karimi, L.; Javid, A. H.

    2014-04-01

    Dam construction and surface runoff control is one of the most common approaches for water-needs supply of human societies. However, the increasing development of social activities and hence the subsequent increase in environmental pollutants leads to deterioration of water quality in dam reservoirs and eutrophication process could be intensified. So, the water quality of reservoirs is now one of the key factors in operation and water quality management of reservoirs. Hence, maintaining the quality of the stored water and identification and examination of changes along time has been a constant concern of humans that involves the water authorities. Traditionally, empirical trophic state indices of dam reservoirs often defined based on changes in concentration of effective factors (nutrients) and its consequences (increase in chlorophyll a), have been used as an efficient tool in the definition of dam reservoirs quality. In recent years, modeling techniques such as artificial neural networks have enhanced the prediction capability and the accuracy of these studies. In this study, artificial neural networks have been applied to analyze eutrophication process in the Dez Dam reservoir in Iran. In this paper, feed forward neural network with one input layer, one hidden layer and one output layer was applied using MATLAB neural network toolbox for trophic state index (TSI) analysis in the Dez Dam reservoir. The input data of this network are effective parameters in the eutrophication: nitrogen cycle parameters and phosphorous cycle parameters and parameters that will be changed by eutrophication: Chl a, SD, DO and the output data is TSI. Based on the results from estimation of modified Carlson trophic state index, Dez Dam reservoir is considered to be eutrophic in the early July to mid-November and would be mesotrophic with decrease in temperature. Therefore, a decrease in water quality of the dam reservoir during the warm seasons is expectable. The results indicated that

  15. Investigation on trophic state index by artificial neural networks (case study: Dez Dam of Iran)

    NASA Astrophysics Data System (ADS)

    Saghi, H.; Karimi, L.; Javid, A. H.

    2015-06-01

    Dam construction and surface runoff control is one of the most common approaches for water-needs supply of human societies. However, the increasing development of social activities and hence the subsequent increase in environmental pollutants leads to deterioration of water quality in dam reservoirs and eutrophication process could be intensified. So, the water quality of reservoirs is now one of the key factors in operation and water quality management of reservoirs. Hence, maintaining the quality of the stored water and identification and examination of changes along time has been a constant concern of humans that involves the water authorities. Traditionally, empirical trophic state indices of dam reservoirs often defined based on changes in concentration of effective factors (nutrients) and its consequences (increase in chlorophyll a), have been used as an efficient tool in the definition of dam reservoirs quality. In recent years, modeling techniques such as artificial neural networks have enhanced the prediction capability and the accuracy of these studies. In this study, artificial neural networks have been applied to analyze eutrophication process in the Dez Dam reservoir in Iran. In this paper, feed forward neural network with one input layer, one hidden layer and one output layer was applied using MATLAB neural network toolbox for trophic state index (TSI) analysis in the Dez Dam reservoir. The input data of this network are effective parameters in the eutrophication: nitrogen cycle parameters and phosphorous cycle parameters and parameters that will be changed by eutrophication: Chl a, SD, DO and the output data is TSI. Based on the results from estimation of modified Carlson trophic state index, Dez Dam reservoir is considered to be eutrophic in the early July to mid-November and would be mesotrophic with decrease in temperature. Therefore, a decrease in water quality of the dam reservoir during the warm seasons is expectable. The results indicated that

  16. Indoor Pond Biology

    ERIC Educational Resources Information Center

    Kunkel, Erika R.

    1977-01-01

    This year-long science program involved fifth grade students in the investigation of a meadow pond. Two field trips to collect pond water and organisms were arranged for the beginning and conclusion of the program. Classroom activities were designed to study aquatic organisms, life cycles, populations, and ecosystems. (MA)

  17. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  18. Baseline study of methane emission from anaerobic ponds of palm oil mill effluent treatment.

    PubMed

    Yacob, Shahrakbah; Ali Hassan, Mohd; Shirai, Yoshihito; Wakisaka, Minato; Subash, Sunderaj

    2006-07-31

    The world currently obtains its energy from the fossil fuels such as oil, natural gas and coal. However, the international crisis in the Middle East, rapid depletion of fossil fuel reserves as well as climate change have driven the world towards renewable energy sources which are abundant, untapped and environmentally friendly. Malaysia has abundant biomass resources generated from the agricultural industry particularly the large commodity, palm oil. This paper will focus on palm oil mill effluent (POME) as the source of renewable energy from the generation of methane and establish the current methane emission from the anaerobic treatment facility. The emission was measured from two anaerobic ponds in Felda Serting Palm Oil Mill for 52 weeks. The results showed that the methane content was between 35.0% and 70.0% and biogas flow rate ranged between 0.5 and 2.4 L/min/m(2). Total methane emission per anaerobic pond was 1043.1 kg/day. The total methane emission calculated from the two equations derived from relationships between methane emission and total carbon removal and POME discharged were comparable with field measurement. This study also revealed that anaerobic pond system is more efficient than open digesting tank system for POME treatment. Two main factors affecting the methane emission were mill activities and oil palm seasonal cropping. PMID:16125215

  19. Process studies of odour emissions from effluent ponds using machine-based odour measurement

    NASA Astrophysics Data System (ADS)

    Sohn, J. H.; Smith, R. J.; Yoong, E.

    Replicable experimental studies using a novel experimental facility and a machine-based odour quantification technique were conducted to demonstrate the relationship between odour emission rates and pond loading rates. The odour quantification technique consisted of an electronic nose, AromaScan A32S, and an artificial neural network. Odour concentrations determined by olfactometry were used along with the AromaScan responses to train the artificial neural network. The trained network was able to predict the odour emission rates for the test data with a correlation coefficient of 0.98. Time averaged odour emission rates predicted by the machine-based odour quantification technique, were strongly correlated with volatile solids loading rate, demonstrating the increased magnitude of emissions from a heavily loaded effluent pond. However, it was not possible to obtain the same relationship between volatile solids loading rates and odour emission rates from the individual data. It is concluded that taking a limited number of odour samples over a short period is unlikely to provide a representative rate of odour emissions from an effluent pond. A continuous odour monitoring instrument will be required for that more demanding task.

  20. Sediment retention in constructed wetland ponds--a laboratory study.

    PubMed

    Stephan, Ursula; Hengl, Michael; Schmid, Bernhard H

    2005-01-01

    Laboratory experiments on sediment removal and particle settlement were conducted in a hydraulic laboratory model scaled 1:1 to study processes and mechanisms governing sediment transport under well defined and reproducible conditions. Parameters governing particle settling were varied and their effect studied ceteris paribus. These governing parameters were flow velocity, TSS input concentration, presence of plants, vegetation density, and the presence of wind. Changes in sediment removal due to different parameters were analyzed by means of deposition curves in main flow direction. We found that particle settling is enhanced by increased inflow concentrations of suspended solids in the absence of plant stems (substance used: kaolin), whereas deposition is reduced by wind shear. The presence of plant stems strengthens vertical mixing and, consequently, does not generally result in enhanced deposition of suspended solids. Higher plant densities tend to be associated with lower settling rates. The effect of flow velocity on particle settling is small for the present experimental set-up. PMID:15921291

  1. Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States.

    PubMed

    Lazar, Julia G; Addy, Kelly; Gold, Arthur J; Groffman, Peter M; McKinney, Richard A; Kellogg, Dorothy Q

    2015-09-01

    Beaver-created ponds and dams, on the rise in the northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, and connecting streams. We examined seasonal and annual rates of nitrate transformations in three beaver ponds in Rhode Island under enriched nitrate-nitrogen (N) conditions through the use of N mass balance techniques on soil core mesocosm incubations. We recovered approximately 93% of the nitrate N from our mesocosm incubations. Of the added nitrate N, 22 to 39% was transformed during the course of the incubation. Denitrification had the highest rates of transformation (97-236 mg N m d), followed by assimilation into the organic soil N pool (41-93 mg N m d) and ammonium generation (11-14 mg N m d). Our denitrification rates exceeded those in several studies of freshwater ponds and wetlands; however, rates in those ecosystems may have been limited by low concentrations of nitrate. Assuming a density of 0.7 beaver ponds km of catchment area, we estimated that in nitrate-enriched watersheds, beaver pond denitrification can remove approximately 50 to 450 kg nitrate N km catchment area. In rural watersheds of southern New England with high N loading (i.e., 1000 kg km), denitrification from beaver ponds may remove 5 to 45% of watershed nitrate N loading. Beaver ponds represent a relatively new and substantial sink for watershed N if current beaver populations persist. PMID:26436285

  2. Agricultural ponds support amphibian populations

    USGS Publications Warehouse

    Knutson, M.G.; Richardson, W.B.; Reineke, D.M.; Gray, B.R.; Parmelee, J.R.; Weick, S.E.

    2004-01-01

    In some agricultural regions, natural wetlands are scarce, and constructed agricultural ponds may represent important alternative breeding habitats for amphibians. Properly managed, these agricultural ponds may effectively increase the total amount of breeding habitat and help to sustain populations. We studied small, constructed agricultural ponds in southeastern Minnesota to assess their value as amphibian breeding sites. Our study examined habitat factors associated with amphibian reproduction at two spatial scales: the pond and the landscape surrounding the pond. We found that small agricultural ponds in southeastern Minnesota provided breeding habitat for at least 10 species of amphibians. Species richness and multispecies reproductive success were more closely associated with characteristics of the pond (water quality, vegetation, and predators) compared with characteristics of the surrounding landscape, but individual species were associated with both pond and landscape variables. Ponds surrounded by row crops had similar species richness and reproductive success compared with natural wetlands and ponds surrounded by nongrazed pasture. Ponds used for watering livestock had elevated concentrations of phosphorus, higher turbidity, and a trend toward reduced amphibian reproductive success. Species richness was highest in small ponds, ponds with lower total nitrogen concentrations, tiger salamanders (Ambystoma tigrinum) present, and lacking fish. Multispecies reproductive success was best in ponds with lower total nitrogen concentrations, less emergent vegetation, and lacking fish. Habitat factors associated with higher reproductive success varied among individual species. We conclude that small, constructed farm ponds, properly managed, may help sustain amphibian populations in landscapes where natural wetland habitat is rare. We recommend management actions such as limiting livestock access to the pond to improve water quality, reducing nitrogen input, and

  3. Experimental study on mechanism and shape characteristics of suspended flexible dam

    NASA Astrophysics Data System (ADS)

    Wang, Jian-zhong; Fan, Hong-xia; Zhu, Li-jun

    2014-12-01

    Hydraulic structures such as groin, longitudinal dike and seawall are common in water conservancy and water transportation engineering projects at home and abroad, which have long been dominated by solid mass structural form. With brush and stone as building materials, this kind of structure has an obvious engineering effect. However, it not only requires huge capital investments, but also has negative impacts on the ecological environment. The suspended flexible dam is an innovative engineering measure, and few theoretical and experimental researches of this type dam can be found at present. This paper studies the mechanism and shape characteristics of this dam and obtains the dynamic equilibrium equation of flexible dam, the float buoyancy expression, and the condition for transformation among three forms of the underwater shape of the dam. The results are valuable in engineering application and can be used as the reference for the future work due to the distinctive design philosophy, the small negative effects on environment and the consistency for sustainable development.

  4. Estimating the ratio of pond size to irrigated soybeans land in Mississippi: A case study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although more on-farm storage ponds have been constructed in recent years to mitigate groundwater resources depletion in Mississippi, little effort has been devoted to estimating the ratio of pond size to irrigated crop land based on pond matric and its hydrological conditions. Knowledge of this ra...

  5. Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

    NASA Astrophysics Data System (ADS)

    Reynolds, Z. A.

    2015-12-01

    Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how

  6. Colonial Era Impoundment of the Northeastern United States: Beaver Trapping and Low- head Dam Construction

    NASA Astrophysics Data System (ADS)

    Salant, N.; Bain, D.; Brandt, S.

    2008-12-01

    Hydrologic systems of the northeastern United States were transformed by European settler activities. The colonial economy shifted engineered water structures from beaver dams to human dams built for power generation. While the geomorphic effects of human-constructed dams have recently garnered considerable attention, few studies have investigated how intensive trapping for the fur trade, the near extermination of the Northeast beaver population, and the consequent loss of beaver ponds altered the regional water balance. Although reconstructions of colonial beaver populations have been made, none link the decline in beavers to its hydrologic impact. Beaver population models based on pre-colonial population estimates, historic harvest rates, and current-day population dynamics were used to simulate the corresponding decrease in pond numbers over time. Beaver populations declined dramatically during the seventeenth century, with harvest rates estimated at 2,000-10,000 beavers per year, resulting in expatriation in some sub-regions by the early 1700s. Using contemporary estimates of beaver pond volumes, the calculated loss in pond storage between 1600 and 1840 was approximately 17 million cubic meters of water and sediment, considerably larger than estimated storage gains from dam construction in the same period, suggesting that beaver eradication was a major driver of hydrologic change during the colonial era.

  7. Exploring Pond Water

    ERIC Educational Resources Information Center

    Raun, Chester E.; Metz, William C.

    1975-01-01

    An activity utilizing a bucket of pond water for study of microorganisms as presented to elementary school preservice and inservice teachers, and subsequently to their pupils, is described. Procedures for collecting, studying, tabulating data and extended activities are presented. (EB)

  8. 29. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. View from downstream of intake, dam wind wall to right, lower wall of overflow chute in left foreground (contains pipes and small dam, possibly for water pumping). West 320 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  9. 6. VIEW OF DAM 83, SHOWING OUTLET CHANNEL FLOWING INTO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF DAM 83, SHOWING OUTLET CHANNEL FLOWING INTO POND A WITH DIVERSION GATES LONG EAST (LEFT) SIDE OF OUTLET CHANNEL, LOOKING SOUTH FROM DOWNSTREAM FACE OF THE DAM - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  10. Surface Sediments in Precooler Ponds 2, 4, and 5: March 2000

    SciTech Connect

    Dunn, D.L.

    2001-01-29

    Pond 2, Pond 4, and Pond 5 are inactive reactor cooling impoundments built in 1961 on the R-Reactor Effluent System in the east-central portion of the Department of Energy's Savannah River Site in Aiken, South Carolina. These precooler ponds are part of the Par Pond cooling water system and are considered part of the Par Pond operable unit. The intent was not to characterize the ponds, but to identify the maximum levels of contamination that could be exposed if the ponds are drained to remove the danger of dam failure.

  11. Insights into the Effects of the Spatial Configuration of Flood Retention Ponds on Flood Frequency

    NASA Astrophysics Data System (ADS)

    Ayalew, T. B.; Krajewski, W. F.; Mantilla, R.

    2014-12-01

    As the construction of large dams for flood control purposes becomes no longer attractive due to their high cost and adverse environmental impacts, the use of spatially distributed flood retention ponds in both urban and rural settings is becoming an alternative flood management practice. However, little is known about how the spatial configuration of ponds and their storage and release capacities relative to their location in the drainage network affect the flood frequency at different locations in the catchment. In this study, we investigate this issue using a continuous simulation approach where a randomly generated rainfall time series is used to derive a hydrologic model that mimics the translation, aggregation, and attenuation of flows along the drainage network. We began by investigating how flood retention ponds that are configured either in series or in parallel affect the flood frequency using a hypothetical catchment (A=30 km2) whose drainage network is idealized using the deterministic Mandelbrot-Viseck tree. Our results show that ponds that are configured in parallel and placed at the upstream section of the basin offer a better peak flood reduction than ponds that are either configured in series along the main stem of the drainage network or a single bigger pond that is located at the outlet. The results also show that, for ponds that are configured in series, emptying the upstream dam first offers better regulation of flood peaks than emptying the downstream pond first. Moreover, our results show that, when the two ponds that are configured in series have different storage capacities, it is better to put the larger pond in the upstream section of the catchment. We further expanded the analysis to the Soap Creek catchment (A=660 km2) located in southeastern Iowa, and simulated a system of 132 flood retention ponds that have already been built across that catchment. Our results show how these ponds modify the flood frequency at different locations in

  12. Hydrologic climate change: are the existing dams still safe? The Flumendosa case study in Sardinia

    NASA Astrophysics Data System (ADS)

    Maccioni, G.; Montaldo, N.; Saba, A.

    2009-04-01

    The problem of the hydraulic safety of existing dams is becoming crucial due to the recent increase of floods. In Sardinia dams were built for both electric production and water supply for irrigation and civil uses during the 1920-1960 period. Recent floods showed a significant increase in magnitude and frequency, supporting the hypothesis of a hydrologic climate change. Are the existing dams still safe? For answering the question 1) a method for estimating the flood hydrograph with return period of 2000 years also accounting for possible climate change is developed, 2) an hydrologic model is implemented, and 3) the hydraulic safety of existing dams is tested. The case study is the Flumendosa river basin (area of about 1300 km2) located in central-eastern Sardinia (Italy), whose reservoir system (3 dams) is the main water supply of southern Sardinia, including its largest city, Cagliari. The smallest dam is located in the upper part of the basin with a drainage area of about 50 km2. At this dam, during the December 2004 flood an extremely high peak discharge of around 2000 m3/s was observed (total daily rain was of 600 mm). In the basin the soils are generally of modest thickness, the vegetation throughout the basin has been in part altered by human activities, with many areas (before covered by scrubs) converted to pasture. Urbanized areas are a minor component. Rainfall and discharge data of historical floods (from 1940) were acquired so that a fully evaluation of the hydrologic model has been performed. The distributed hydrologic model is an event model (FEST) which assesses runoff through a simplified approach based on Soil Conservation Service equations and runoff propagation through the Muskingum-Cunge approach. The FEST model well simulates historical and recent floods. The results demonstrated that the dams are not safe for the estimated flood with return period of 2000 year, but also demonstrated the extreme uncertainty in the estimate of floods with

  13. Appropriate small dam management for minimizing catchment-wide safety threats: International benchmarked guidelines and demonstrative cases studies

    NASA Astrophysics Data System (ADS)

    Pisaniello, John D.; Tingey-Holyoak, Joanne; Burritt, Roger L.

    2012-01-01

    Small dam safety is generally being ignored. The potential for dam failure resulting in catastrophic consequences for downstream communities, property, and the environment, warrants exploration of the threats and policy issues associated with the management of small/farm dams. The paper achieves this through a comparative analysis of differing levels of dam safety assurance policy: absent, driven, strong, and model. A strategic review is undertaken to establish international dam safety policy benchmarks and to identify a best practice model. A cost-effective engineering/accounting tool is presented to assist the policy selection process and complement the best practice model. The paper then demonstrates the significance of the small-dam safety problem with a case study of four Australian States,policy-absent South Australia, policy-driven Victoria, policy-strong New South Wales, and policy-modelTasmania. Surveys of farmer behavior practices provide empirical evidence of the importance of policy and its proper implementation. Both individual and cumulative farm dam failure threats are addressed and, with supporting empirical evidence, the need for "appropriate" supervision of small dams is demonstrated. The paper adds to the existing international dam policy literature by identifying acceptable minimum level practice in private/farm dam safety assurance policy as well as updated international best practice policy guidelines while providing case study demonstration of how to apply the guidelines and empirical reinforcement of the need for "appropriate" policy. The policy guidelines, cost-effective technology, and comparative lessons presented can assist any jurisdiction to determine and implement appropriate dam safety policy.

  14. Evaluation of the Pseudostatic Analyses of Earth Dams Using FE Simulation and Observed Earthquake-Induced Deformations: Case Studies of Upper San Fernando and Kitayama Dams

    PubMed Central

    Akhlaghi, Tohid

    2014-01-01

    Evaluation of the accuracy of the pseudostatic approach is governed by the accuracy with which the simple pseudostatic inertial forces represent the complex dynamic inertial forces that actually exist in an earthquake. In this study, the Upper San Fernando and Kitayama earth dams, which have been designed using the pseudostatic approach and damaged during the 1971 San Fernando and 1995 Kobe earthquakes, were investigated and analyzed. The finite element models of the dams were prepared based on the detailed available data and results of in situ and laboratory material tests. Dynamic analyses were conducted to simulate the earthquake-induced deformations of the dams using the computer program Plaxis code. Then the pseudostatic seismic coefficient used in the design and analyses of the dams were compared with the seismic coefficients obtained from dynamic analyses of the simulated model as well as the other available proposed pseudostatic correlations. Based on the comparisons made, the accuracy and reliability of the pseudostatic seismic coefficients are evaluated and discussed. PMID:24616636

  15. 2. VIEW OF POND B, LOOKING NORTHEAST FROM THE WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF POND B, LOOKING NORTHEAST FROM THE WEST SIDE OF THE SOURIS RIVER VALLEY, DUE SOUTH OF THE LOOKOUT TOWER - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Surrey (England), ND

  16. Studying Pond Life with Primary-Age Children: The Project Approach in Action.

    ERIC Educational Resources Information Center

    Warner, Laverne; Morse, Pam

    2001-01-01

    Describes the development, implementation, and results of a pond life elementary student research project. Utilizing the pond life example, provides guidelines for children's research projects including the implementation of the K-W-L (know-want to know- learned) strategy with the children's reports/projects. Provides resources utilized in the…

  17. Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams).

    PubMed

    Heydari, Mohammad; Othman, Faridah; Taghieh, Mahmood

    2016-01-01

    Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam's location (Series and parallel), conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands. PMID:27248152

  18. Spatial Multicriteria Decision Analysis of Flood Risks in Aging-Dam Management in China: A Framework and Case Study

    PubMed Central

    Yang, Meng; Qian, Xin; Zhang, Yuchao; Sheng, Jinbao; Shen, Dengle; Ge, Yi

    2011-01-01

    Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites. PMID:21655125

  19. 12. Upstream view showing thelower log pond log chute in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Upstream view showing thelower log pond log chute in the main channel of the Hudson River. The log chute in the dam can be seen in the background. Facing southwest. - Glens Falls Dam, 100' to 450' West of U.S. Route 9 Bridge Spanning Hudson River, Glens Falls, Warren County, NY

  20. Sea lice, Caligus rotundigenitalis infestations and its management in pond cultured pearlspot, Etroplus suratensis in Gujarat: a case study.

    PubMed

    Solanki, Haresh G; Patil, Prasanna Kumar; Vanza, Jesing G; Patel, Pritesh; Sethi, Satyanarayana; Gopal, Chavali

    2016-06-01

    Highly popular and delicious fish of Kerala (India), pearlspot, Etroplus suratensis is known for its ability to tolerate wide range of salinity, omnivorous feeding behavior. Present report documents the occurrence and management of Caligus rotundigenitalis in brackishwater pond meant for culture demonstration of pearlspot in Gujarat, (India). A brackishwater aquaculture pond (1,500 sq m) was stocked with pearlspot fry (2.60 ± 0.83 g; 4.31 ± 0.82 cm) @ 25,000 ha(-1). On the 46th day of culture couple of dead fish were observed which gradually increased to 120 per day by 52nd day. Following the close observation parasitic infestation was noticed on gills cavities ranging from 15 to 20 numbers per fish. These characteristic features confirmed the parasite as C. rotundigenitalis. As a therapeutic measure the infested pond was successfully treated with Butox(®) @ 300 ml/ha (Deltamethrin 12.5 mg) and repeat dose was administered 2 weeks later. The results of the study suggest the possible therapeutic value of Deltamethrin in treatment of caligid infestation in pond cultured pearlspot. PMID:27413343

  1. CFD study to determine the optimal configuration of aerators in a full-scale waste stabilization pond.

    PubMed

    Alvarado, Andres; Vesvikar, Mehul; Cisneros, Juan F; Maere, Thomas; Goethals, Peter; Nopens, Ingmar

    2013-09-01

    Aerated lagoons (ALs) are important variants of the pond wastewater treatment technology that have not received much attention in the literature. The hydraulic behaviour of ALs and especially the Facultative aerated lagoons (FALs) is very complex since the aeration in these systems is designed for oxygen transfer but not necessarily to create complete mixing. In this work, the energy expenditure of the aerators was studied by means of a scenario analysis. 3D CFD models (one phase and multiphase) of a 3 ha FAL in a waste stabilization pond system in Cuenca (Ecuador) were built for different configurations of aerators. The thrust produced by the aerators was modelled by an external momentum source applied as velocity vectors into the pond fluid. The predictions of a single phase model were in satisfactory agreement with experimental results. Subsequently, a scenario analysis assessing several aeration schemes with different numbers of aerators in operation were tested with respect to velocity profiles and residence time distribution (RTD) curves. This analysis showed that the aeration scheme with all 10 aerators switched on produces a similar hydraulic behaviour compared to using only 6 or 8 aerators. The current operational schemes comprise of switching off some aerators during the peak hours of the day and operating all 10 aerators during night. This current practice could be economically replaced by continuously operating 4 or 6 aerators without significantly affecting the overall mixing. Furthermore, a continuous mixing regime minimises the sediment oxygen demand enhancing the oxygen levels in the pond. PMID:23764602

  2. Study of the influence of temperature and water level of the reservoir about the displacement of a concrete dam

    NASA Astrophysics Data System (ADS)

    Oro, S. R.; Mafioleti, T. R.; Chaves Neto, A.; Garcia, S. R. P.; Neumann Júnior, C.

    2016-02-01

    Multivariate techniques are used in this study to analyze the monitoring data displacements of a concrete dam, measured by means of pendulums, extensometer bases and multiple rod extensometers, taking into account the action of environmental conditions, bounded by the surface temperature of the concrete at ambient temperature and the tank water level. The canonical correlation analysis is used to evaluate the influence of environmental variables in the displacement of structures and dam foundations. The factor analysis is used to identify data sources of variability and order the sensors according to the action of factors. The dates of the measurements are grouped according to similarities in the present observations, by applying the cluster analysis. Then the discriminant analysis is used to assess the groups as to their homogeneity. The results demonstrate that the techniques used for distinguishing the dam responses and identify the effects of changes in environmental conditions on the displacements of the structures and dam foundations.

  3. Beaver dams and overbank floods influence groundwater-surface water interactions of a Rocky Mountain riparian area

    NASA Astrophysics Data System (ADS)

    Westbrook, Cherie J.; Cooper, David J.; Baker, Bruce W.

    2006-06-01

    Overbank flooding is recognized by hydrologists as a key process that drives hydrogeomorphic and ecological dynamics in mountain valleys. Beaver create dams that some ecologists have assumed may also drive riparian hydrologic processes, but empirical evidence is lacking. We examined the influence of two in-channel beaver dams and a 10 year flood event on surface inundation, groundwater levels, and flow patterns in a broad alluvial valley during the summers of 2002-2005. We studied a 1.5 km reach of the fourth-order Colorado River in Rocky Mountain National Park (RMNP), Colorado, USA. The beaver dams and ponds greatly enhanced the depth, extent, and duration of inundation associated with floods; they also elevate the water table during both high and low flows. Unlike previous studies we found the main effects of beaver on hydrologic processes occurred downstream of the dam rather than being confined to the near-pond area. Beaver dams on the Colorado River caused river water to move around them as surface runoff and groundwater seepage during both high- and low-flow periods. The beaver dams attenuated the expected water table decline in the drier summer months for 9 and 12 ha of the 58 ha study area. Thus we provide empirical evidence that beaver can influence hydrologic processes during the peak flow and low-flow periods on some streams, suggesting that beaver can create and maintain hydrologic regimes suitable for the formation and persistence of wetlands.

  4. Beaver dams and overbank floods influence groundwater-surface water interactions of a Rocky Mountain riparian area

    USGS Publications Warehouse

    Westbrook, C.J.; Cooper, D.J.; Baker, B.W.

    2006-01-01

    Overbank flooding is recognized by hydrologists as a key process that drives hydrogeomorphic and ecological dynamics in mountain valleys. Beaver create dams that some ecologists have assumed may also drive riparian hydrologic processes, but empirical evidence is lacking. We examined the influence of two in-channel beaver dams and a 10 year flood event on surface inundation, groundwater levels, and flow patterns in a broad alluvial valley during the summers of 2002-2005. We studied a 1.5 km reach of the fourth-order Colorado River in Rocky Mountain National Park (RMNP), Colorado, USA. The beaver dams and ponds greatly enhanced the depth, extent, and duration of, inundation associated with floods; they also elevate the water table during both high and low flows. Unlike previous studies we found the main effects of beaver on hydrologic processes occurred downstream of the dam rather than being confined to the near-pond area. Beaver dams on the Colorado River caused river water to move around them as surface runoff and groundwater seepage during both high- and low-flow periods. The beaver dams attenuated the expected water table decline in the drier summer months for 9 and 12 ha of the 58 ha study area. Thus we provide empirical evidence that beaver can influence hydrologic processes during the peak flow and low-flow periods on some streams, suggesting that beaver can create and maintain hydrologic regimes suitable for the formation and persistence of wetlands. Copyright 2006 by the American Geophysical Union.

  5. Experimental Study on Cracking, Reinforcement, and Overall Stability of the Xiaowan Super-High Arch Dam

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Zhou, Weiyuan; Liu, Hongyuan

    2015-03-01

    The Xiaowan super-high arch dam has faced challenging construction problems. Here, we provide a scientifically-based reference for applying geomechanical model testing to support the nonlinear design of super-high arch dams. We applied experimental similarity theory and techniques. Based on four 3D geomechanical model tests, the dam stress characteristics, deformation distribution, and the safety factors of the dam foundation were identified and compared. We also analyzed cracking characteristics of the up- and downstream dam surfaces and induced joints in the dam heel, the rock mass failure process of the dam-foundation interface, and the abutments. We propose foundation reinforcement measures for weak rock masses, alteration zones, and other faults in the abutments based on the 3D and plane tests each at a different elevation. The results show that all dam deformations remained normal with no yielding or tensile cracking under a normal water load. The reinforced rock mass increased the crack initial safety in the dam heel and toe by ~20 %. The minimum crack initial safety factor ( K 1) of the dam heel was 1.4. The induced joint in the dam heel contributed to a reduction in tensile stress at the upstream dam heel, improving K 1. Compared with similar projects following reinforcement measures, the abutment stiffness and overall stability of the Xiaowan arch dam satisfy operational requirements. Four years of monitoring operations show that key areas near the dam remained normal and the dam foundation is functioning well. Our results may also be applicable to the design and construction of similar projects worldwide.

  6. Solar pond

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1978-01-01

    Shallow pools of liquid to collect low-temperature solar generated thermal energy are described. Narrow elongated trenches, grouped together over a wide area, are lined with a heat-absorbing black liner. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethlene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out ultraviolet radiation and trap in infrared radiation.

  7. The Pond Is Our Laboratory

    ERIC Educational Resources Information Center

    Marchewka, Barbara Turco

    1978-01-01

    This science teacher's laboratory is a pond within walking distance of his school that provides a stimulating environment for exploring the natural world. With simple materials students practice making careful observations, taking measurements and compiling and graphing information for their science studies. They also extend their pond experiences…

  8. Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams)

    PubMed Central

    Othman, Faridah; Taghieh, Mahmood

    2016-01-01

    Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam’s location (Series and parallel), conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands. PMID:27248152

  9. Impact of Beaver Pond Colonization History on Methylmercury Concentrations in Surface Water.

    PubMed

    Levanoni, Oded; Bishop, Kevin; Mckie, Brendan G; Hartman, Göran; Eklöf, Karin; Ecke, Frauke

    2015-11-01

    Elevated concentrations of methylmercury (MeHg) in freshwater ecosystems are of major environmental concern in large parts of the northern hemisphere. Beaver ponds have been identified as a potentially important source of MeHg. The role of beavers might be especially pronounced in large parts of Europe, where beaver populations have expanded rapidly following near-extirpation. This study evaluates the role of the age and colonization history (encompassing patterns of use and reuse) of ponds constructed by the Eurasian beaver Castor fiber in regulating MeHg concentrations in Swedish streams. In 12 beaver systems located in three regions, we quantified MeHg concentrations together with other relevant parameters on five occasions per year in 2012-2013. Five were pioneer systems, inundated for the first time since beaver extirpation, and seven were recolonized, with dams reconstructed by newly recolonizing beavers. MeHg concentrations in pioneer but not in recolonized beaver systems were up to 3.5 fold higher downstream than upstream of the ponds, and varied between seasons and years. Our results show that pioneer inundation by beavers can increase MeHg concentrations in streams, but that this effect is negligible when dams are reconstructed on previously used ponds. We therefore expect that the recovery and expansion of beavers in the boreal system will only have a transitional effect on MeHg in the environment. PMID:26450629

  10. Tailings Pond Characterization And Designing Through Geophysical Surveys In Dipping Sedimentary Formations

    NASA Astrophysics Data System (ADS)

    Muralidharan, D.; Andrade, R.; Anand, K.; Sathish, R.; Goud, K.

    2009-12-01

    two magnetic profiles inside the tailings pond and surrounding areas on the southern part of the tailings pond enabled in identifying two parallel east-west intrusive bodies forming the impermeable boundary for the tailings pond. The shallow seismic refraction and the geophysical studies in and around the proposed tailings pond brought out the suitability of the site, even when the toxic elements percolates through the subsurface formations in to the groundwater system, the existence of dykes on either side of the proposed ponding area won’t allow the water to move across them thus by restricting the contamination within the tailings pond area. Similarly, the delineation of a fault zone within the tailings pond area helped in shifting the proposed dam axis of the pond to avoid leakage through the fault zone causing concern to environment pollution.

  11. 26. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. Remains of dam structures on right and left banks. North/northeast 80 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  12. 7. VIEW OF DAM 83, SHOWING DIVERSION GATES TO SOURIS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF DAM 83, SHOWING DIVERSION GATES TO SOURIS RIVER CHANNEL (LEFT) AND POND A (RIGHT) FROM THE WEST SIDE OF THE OUTLET CHANNEL, LOOKING SOUTHEAST (for view of the original diversion gate, see historic photograph, HAER No. ND-3-A-15) - Upper Souris National Wildlife Refuge, Dam 83, Souris River Basin, Foxholm, Surrey (England), ND

  13. 106. DAM EARTH DIKE SUBMERSIBLE DAMS & DIKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    106. DAM - EARTH DIKE - SUBMERSIBLE DAMS & DIKE CONN. AT MOVABLE DAM (ML-8-52/2-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  14. [Study on nitrogen cycling and transformations in a duckweed pond by means of modeling analysis].

    PubMed

    Peng, Jian-feng; Song, Yong-hui; Yuan, Peng; Wang, Bao-zhen

    2006-10-01

    Based on the simulated results from N cycling and transformation model of duckweed pond, the influences of different major transfer pathways on various nitrogen removal performances are investigated. The effects of seasonal variations of water conditions on nitrogen transformations are determined. The simulated results show that nitrification and denitrification were the major removal pathways for nitrogen in duckweed pond, and the removal contributions of organic nitrogen sedimentation and ammonia volatilization for total nitrogen removal were less than 2.1%. Furthermore, in duckweed pond, nitrification and denitrification decided the removal efficiencies of ammonia and NOx., respectively; both algae decaying and organic nitrogen ammonification controlled primarily the organic nitrogen removal performances; both organic nitrogen sedimentation and mineralization of sedimentary nitrogen determined the variations of sedimentary nitrogen. Duckweed pond with duckweed growing largely can increase sharply algae mortality and keep the low content of algae in effluent. Besides, through accelerating the nitrification and denitrification rate, duckweed can evidently improve the removal efficiencies of total nitrogen. PMID:17256592

  15. Ultraviolet light exposure and lens opacities: the Beaver Dam Eye Study.

    PubMed Central

    Cruickshanks, K J; Klein, B E; Klein, R

    1992-01-01

    OBJECTIVES. Exposure to sunlight may be a risk factor for the development of cataract. The relationships between exposure to sunlight and to the ultraviolet-B (UVB) component of light and the prevalence of lens opacities were examined in the Beaver Dam Eye Study. METHODS. Persons 43 to 84 years of age residing in Beaver Dam, Wisconsin, were examined using standardized photographic assessments of lens opacities. A questionnaire about medical history and exposure to light was administered. RESULTS. After adjusting for other risk factors, men who had higher levels of average annual ambient UVB light were 1.36 times more likely to have more severe cortical opacities than men with lower levels. However, UVB exposure was not found to be associated with nuclear sclerosis or posterior subcapsular opacities in men. Moreover, no associations with UVB exposure were found for women, who were less likely to be exposed to UVB. CONCLUSIONS: Exposure to UVB light may be associated with the severity of cortical opacities in men. However, the lack of an association in women, the group more likely to have cortical opacities, suggests that other factors may be more important in the pathogenesis of lens opacities. PMID:1456342

  16. A study of possible ground-motion amplification at the Coyote Lake Dam, California

    USGS Publications Warehouse

    Boore, D.M.; Graizer, V.M.; Tinsley, J.C.; Shakal, A.F.

    2004-01-01

    The abutment site at the Coyote Lake Dam recorded an unusually large peak acceleration of 1.29g during the 1984 Morgan Hill earthquake. Following this earthquake another strong-motion station was installed about 700 m downstream from the abutment station. We study all events (seven) recorded on these stations, using ratios of peak accelerations, spectral ratios, and particle motion polarization (using holograms) to investigate the relative ground motion at the two sites. We find that in all but one case the motion at the abutment site is larger than the downstream site over a broad frequency band. The polarizations are similar for the two sites for a given event, but can vary from one event to another. This suggests that the dam itself is not strongly influencing the records. Although we can be sure that the relative motion is usually larger at the abutment site, we cannot conclude that there is anomalous site amplification at the abutment site. The downstream site could have lower-than-usual near-surface amplifications. On the other hand, the geology near the abutment site is extremely complex and includes fault slivers, with rapid lateral changes in materials and presumably seismic velocities. For this reason alone, the abutment site should not be considered a normal free-field site.

  17. The geomorphic influences of beaver dams and failures of beaver dams

    NASA Astrophysics Data System (ADS)

    Butler, David R.; Malanson, George P.

    2005-10-01

    Uncounted millions of beaver ponds and dams existed in North America prior to European contact and colonization. These ponds acted as sediment traps that contained tens to hundreds of billions of cubic meters of sediment that would otherwise have passed through the fluvial system. Removal of beavers by overtrapping in the 16th-19th centuries severely reduced their number and the number of ponds and dams. Dam removal altered the fluvial landscape of North America, inducing sediment evacuation and entrenchment in concert with widespread reduction in the wetlands environments. Partial recovery of beaver populations in the 20th century has allowed reoccupation of the entirety of the pre-contact range, but at densities of only one-tenth the numbers. Nevertheless, modern beaver ponds also trap large volumes of sediment in the high hundred millions to low billions of cubic meters range. Failure of beaver dams is a more common phenomenon than often assumed in the literature. During the past 20 years, numerous cases of dam failure have been documented that resulted in outburst floods. These floods have been responsible for 13 deaths and numerous injuries, including significant impacts on railway lines.

  18. Application of the contingent valuation method in a developing country: a case study of the Yusufeli dam in northeast Turkey.

    PubMed

    Alp, Emre; Yetiş, Ulkü

    2010-01-01

    Hydroelectric power plants and dams often play an important role in developing countries in terms of their contribution to economy. In accordance with the energy policies of Turkish Republic, Yusufeli Dam and Hydroelectric Power Plant in Northeastern Turkey have been initiated. In this study, the Contingent Valuation Method (CVM) was conducted in Yusufeli Village to determine the environmental costs of the Yusufeli Project. The purpose is to assess the willingness to pay (WTP) of Yusufeli Village residents for restoration of the environmental impacts of the dam project and also to investigate the underlying economic, psychological, and social motivations for WTP. WTP was calculated as US$761 per person which can further be used in the cost-benefit analysis. The results from the study suggest that application of the CVM in rural and urban areas located in the same region can show differences. PMID:20595759

  19. Synthesis of Sensor Fish Data for Assessment of Fish Passage Conditions at Turbines, Spillways, and Bypass Facilities – Phase 1: The Dalles Dam Spillway Case Study

    SciTech Connect

    Deng, Zhiqun; Serkowski, John A.; Fu, Tao; Carlson, Thomas J.; Richmond, Marshall C.

    2007-12-31

    This report summarizes the characterization of spillway passage conditions at The Dalles Dam in 2006 and the effort to complete a comprehensive database for data sets from The Dalles Dam spillway Sensor Fish and balloon-tagged live fish experiments. Through The Dalles Dam spillway case study, Pacific Northwest National Laboratory (PNNL) researchers evaluated the database as an efficient means for accessing and retrieving system-wide data for the U.S Army Corps of Engineers (USACE).

  20. Rock Mass Behavior Under Hydropower Embankment Dams: A Two-Dimensional Numerical Study

    NASA Astrophysics Data System (ADS)

    Bondarchuk, A.; Ask, M. V. S.; Dahlström, L.-O.; Nordlund, E.

    2012-09-01

    Sweden has more than 190 large hydropower dams, of which about 50 are pure embankment dams and over 100 are concrete/embankment dams. This paper presents results from conceptual analyses of the response of typical Swedish rock mass to the construction of a hydropower embankment dam and its first stages of operation. The aim is to identify locations and magnitudes of displacements that are occurring in the rock foundation and grout curtain after construction of the dam, the first filling of its water reservoir, and after one seasonal variation of the water table. Coupled hydro-mechanical analysis was conducted using the two-dimensional distinct element program UDEC. Series of the simulations have been performed and the results show that the first filling of the reservoir and variation of water table induce largest magnitudes of displacement, with the greatest values obtained from the two models with high differential horizontal stresses and smallest spacing of sub-vertical fractures. These results may help identifying the condition of the dam foundation and contribute to the development of proper maintenance measures, which guarantee the safety and functionality of the dam. Additionally, newly developed dams may use these results for the estimation of the possible response of the rock foundation to the construction.

  1. Experimental Study of Overtopping Induced Landslide Dam Break Flow and Two Layer Two Phase Mixture Model

    NASA Astrophysics Data System (ADS)

    Liu, L.; Duan, J. G.; Zhong, D.; Zhang, H.

    2013-12-01

    A series of experiments were conducted to investigate flood flow generated by the failure of landslide dams due to overtopping. These experiments aim to quantify the influences of inflow discharge, downstream slope, width of dam crest, dam height, and dam material on the flood flow. Images from high-speed cameras are used to determine the profiles of dam body and flow discharge during the failure processes. Results showed that the water level in the upstream reservoir and the erosion of dam body are the dominant factors affecting the downstream flood flow. A physical-based model is established to calculate the arriving time and the peak discharge of dam break flow using two phase mixture model. Both analytical and numerical solutions were derived for the model. The modelling results were verified using data from this and several other laboratory experimental datasets. The agreement between the calculated and measured data showed the applicability of the proposed model for predicting the peak discharge of overtopping induced dam break flow.

  2. Effects of pond draining on biodiversity and water quality of farm ponds.

    PubMed

    Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

    2013-12-01

    Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo. PMID:23869702

  3. Relation of smoking to the incidence of age-related maculopathy. The Beaver Dam Eye Study.

    PubMed

    Klein, R; Klein, B E; Moss, S E

    1998-01-15

    To date, a number of reports have been published on the relation of cigarette smoking to age-related maculopathy, an important cause of blindness in the United States. However, few studies have examined the relation between smoking and the incidence of age-related maculopathy. In this report, the authors examine this association in persons aged 43-86 years (n = 3,583) at baseline who were participants in the baseline examination and 5-year follow-up of the Beaver Dam Eye Study, Beaver Dam, Wisconsin (1988-1990 and 1993-1995). Exposure data on cigarette smoking were obtained from questions about present and past smoking, duration of smoking, and the number of cigarettes smoked per day. Age-related maculopathy status was determined by grading stereoscopic color fundus photographs using the Wisconsin Age-related Maculopathy Grading System. After controlling for age, sex, vitamin supplement use, and beer consumption, men who smoked greater amounts of cigarettes were more likely to develop early age-related maculopathy (odds ratio (OR) per 10 pack-years smoked = 1.06, 95% confidence interval (CI) 1.00-1.13, p = 0.06) than men who had smoked less. This association was not observed in women. Men (OR = 3.21, 95% CI 1.09-9.45) and women (OR = 2.20, 95% CI 1.04-4.66) who were current smokers at the time of the baseline examination had significantly higher odds of developing large drusen (> or = 250 microns in diameter) after 5 years than those who had never smoked or who quit before the baseline study. Current or past history of cigarette smoking was not related to the incidence of retinal pigment epithelial depigmentation. The authors conclude that smoking appears to be related to the incidence of some lesions associated with early age-related maculopathy. PMID:9456998

  4. The Legacy Ecosystem Management Framework: From Theory to Application in the Detention Pond Case Study

    SciTech Connect

    Coty, J; Stevenson, M; Vogt, K A

    2002-02-01

    The Detention Pond is a constructed and lined storm water treatment basin at Lawrence Livermore National Laboratory that serves multiple stakeholder objectives and programmatic goals. This paper examines the process and outcome involved in the development of a new management plan for the Detention Pond. The plan was created using a new ecosystem management tool, the Legacy Framework. This stakeholder-driven conceptual framework provides an interdisciplinary methodology for determining ecosystem health, appropriate management strategies, and sensitive indicators. The conceptual framework, the Detention Ponds project, and the use of the framework in the context of the project, are described and evaluated, and evaluative criteria for this and other ecosystem management frameworks are offered. The project benefited in several ways from use of the Legacy Framework, although refinements to the framework are suggested. The stakeholder process created a context and environment in which team members became receptive to using an ecosystem management approach to evaluate and support management alternatives previously not considered. This allowed for the unanimous agreement to pursue support from upper management and organizational funding to implement a progressive management strategy. The greatly improved stakeholder relations resulted in upper management support for the project.

  5. Analysis of Stream Channel Geometry Temporal and Spatial Evolution after Historic Dam Removal - two French case studies

    NASA Astrophysics Data System (ADS)

    Slawson, Deborah; Manière, Louis; Marchandeau, Florent

    2014-05-01

    IRSTEA, in partnership with the French Office national de l'eau et des milieux aquatiques (ONEMA), has begun a study of channel geomorphology in small streams where dams have been removed or breached between two and 200 years ago, without any subsequent restoration of the channel in the legacy sediments. A preliminary analysis of two sites in the Morvan, Burgundy, will be presented; a dam breached at the beginning of the 20th century and another in the last decade. Using ergodic reasoning, historical and recent upstream and downstream channel geometry is being used to predict the future temporal and spatial scales of channel physical habitat restoration. With the implementation of the European Water Framework Directive (WFD), dam removal has become a more frequently used method for restoring stream ecological continuity. In France, these obstacles are ubiquitous in medium and small streams and considerably reduce lateral and longitudinal connectivity. Improvement in the hydromorphologically controlled, physical habitat, particularly flow and sediment transport regimes, is often essential to improvement in stream biology. However, dam removal may cause long-term disturbances in flow and sediment transport regimes. In the absence of channel restoration measures in addition to dam removal, these disturbances may result in long-term negative impacts on fish, macroinvertebrate, and riparian plant physical habitat. These negative impacts may include channel incision and lowering of the water table, disconnection from floodplains, increased stream power and bed scouring, and increased sediment load from headcutting and bank erosion. Over time, these negative impacts may resolve themselves. However, the time frame necessary for reestablishing adequate physical habitat is not well-known. Some studies have indicated that many decades or longer may be required, depending on a variety of factors. Under the WFD, the REstoring rivers FOR effective catchment Management (REFORM

  6. Water Management Models in Practice: A Case Study of the Aswan High Dam

    NASA Astrophysics Data System (ADS)

    El-Ashry, M. T.; Alford, D. L.

    1984-04-01

    The stated purpose of this volume is the development and evaluation of operating policies for the Aswan High Dam and their relation to the development of water resources policy in Egypt. That objective is admirably fulfilled through discussions of water use in Egypt and the operation objectives of the High Dam, the behavior of the physical system and simulation of the reservoir, a realtime management model of the dam, management of water shortages and trade-offs between major uses, and coordinated operation of the dam with new upstream as well as downstream developments.The High Dam has been a source of controversy, particularly with regard to its environmental impacts. Its adverse effects include changes in the water table and attendant salt buildup in irrigated areas, excessive growth of aquatic plants below the dam, shoreline erosion, and increases in water-borne diseases such as schistosomiasis (bilharzia). The dam was intended to offset rapid population growth by increasing food supplies through the transformation of irrigated land in southern Egypt from seasonal to perennial cultivation and by providing water for the reclamation of desert land. Unfortunately, such benefits have been outstripped by the rapidly growing population, and water shortages will be experienced by the end of the century.

  7. Study on Optimal Grouting Timing for Controlling Uplift Deformation of a Super High Arch Dam

    NASA Astrophysics Data System (ADS)

    Lin, Peng; Zhu, Xiaoxu; Li, Qingbin; Liu, Hongyuan; Yu, Yongjun

    2016-01-01

    A grouting model is developed for use during the grouting of the complex foundation of a super high arch dam. The purpose as to determine the optimal grouting timing and appropriate grouting pressure involved in controlling the uplift deformation of the dam. The model determines the optimal grouting time as the height of the arch dam increases with the concrete pouring, by checking the tensile stresses in the dam against standard specifications. The appropriate grouting pressures are given on the basis of the actual grouting pressures monitored during the upstream riverbed foundation grouting. An engineering procedure, applying the model, was then proposed and used during foundation grouting under the toe block of the Xiluodu super high-arch dam in south-western China. The quality of the foundation grouting was evaluated against the results from pressurized water permeability tests, acoustic wave velocity tests, elastic modulus tests and panoramic photographing of the rockmass on completion of the foundation grouting. The results indicated that the proposed grouting model can be applied to effectively reduce the uplift deformation and associated cracking risk for super high arch dams, and it can be concluded that the proposed engineering grouting procedure is a valuable tool for improving foundation grouting under the toe blocks of a super high arch dam.

  8. 78 FR 49735 - Intent To Prepare a Draft Environmental Impact Statement for Dam Safety Study, Lake Lewisville...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... flood risk management, ] water supply, recreation and non-Federal hydropower. Top of conservation pool... conservation pool of Lewisville was raised from elevation 515 to 522 on November 30, 1988. At elevation 522... Safety Study, Lake Lewisville Dam, Elm Fork Trinity River, Denton County, Texas AGENCY: Department of...

  9. Classification of the alterations of beaver dams to headwater streams in northeastern Connecticut, U.S.A.

    NASA Astrophysics Data System (ADS)

    Burchsted, Denise; Daniels, Melinda D.

    2014-01-01

    Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the impact of beaver dams at larger scales, this study examines channel shape and sediment distribution in thirty river reaches in northeastern Connecticut, U.S.A. The study reaches fall within the broader categories of impounded and free-flowing segments, leaving a third segment class of beaver meadows requiring additional study. Each of the study reaches were classified at the reach scale as free-flowing, valley-wide beaver pond, in-channel beaver pond, and downstream of beaver dam. The bankfull channel width to depth ratios and channel widths normalized by watershed area vary significantly across the study reach classes. Additionally, reaches modified by beaver dams have finer sediment distributions. This paper provides the first quantitative geomorphic descriptions of the in-channel beaver pond and reaches downstream of beaver dams. Given the different channel shapes and sediment distributions, we infer that geomorphic processes are longitudinally decoupled by these frequent barriers that control local base level. These barriers generate heterogeneity within a river network by greatly increasing the range of channel morphology and by generating patches controlled by different processes. Therefore, in spite of the small size of individual beaver dams, the cumulative effect of multiple dams has the potential to modify processes at larger spatial scales. To improve assessment of the

  10. 107. DAM EARTH DIKE SUBMERSIBLE DAMS PLANS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    107. DAM - EARTH DIKE - SUBMERSIBLE DAMS - PLANS & SECTIONS (ML-8-52/3-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  11. Hydropower and the environment: A case study at Glen Canyon Dam

    SciTech Connect

    Wegner, D.L.

    1995-12-31

    The management of hydroelectric resources in the Colorado River requires a balancing of hydrologic, social, natural and cultural resources. The resulting management often has to deal with inherently conflicting objectives, short and long-term goals, time frames and operational flexibility. Glen Canyon Dam, AZ, on the Colorado River, controls the release of water into the Grand Canyon. The dam has been under intense public scrutiny since it was completed in 1963. An Environmental Impact Statement evaluating the future operations and options for Glen Canyon Dam was initiated by the Department of the Interior in 1989 and completed in 1995. An Adaptive Management approach to future operational management has been developed as part of the Glen Canyon Dam Environmental Impact Statement process. Future operations at Glen Canyon Dam will take into consideration the need to balance water movement and hydroelectricity development with natural, recreation, Native American and cultural needs. Future management of rivers requires acknowledgement of the dynamic nature of ecosystems and the need to link scientific information into the decision-making process. Lessons learned and programs developed at Glen Canyon Dam may be applied to other river systems.

  12. Erosion risk analysis by GIS in environmental impact assessments: a case study--Seyhan Köprü Dam construction.

    PubMed

    Sahin, S; Kurum, E

    2002-11-01

    Environmental Impact Assessment (EIA) is a systematically constructed procedure whereby environmental impacts caused by proposed projects are examined. Geographical Information Systems (GIS) are crucially efficient tools for impact assessment and their use is likely to dramatically increase in the near future. GIS have been applied to a wide range of different impact assessment projects and dams among them have been taken as the case work in this article. EIA Regulation in force in Turkey requires the analysis of steering natural processes that can be adversely affected by the proposed project, particularly in the section of the analysis of the areas with higher landscape value. At this point, the true potential value of GIS lies in its ability to analyze spatial data with accuracy. This study is an attempt to analyze by GIS the areas with higher landscape value in the impact assessment of dam constructions in the case of Seyhan-Köprü Hydroelectric Dam project proposal. A method needs to be defined before the overlapping step by GIS to analyze the areas with higher landscape value. In the case of Seyhan-Köprü Hydroelectric Dam project proposal of the present work, considering the geological conditions and the steep slopes of the area and the type of the project, the most important natural process is erosion. Therefore, the areas of higher erosion risk were considered as the Areas with Higher Landscape Value from the conservation demands points of view. PMID:12448403

  13. A preliminary observation on the pond culture of European eel, Anguilla anguilla (Linnaeus, 1758) in Egypt: recommendations for future studies.

    PubMed

    El-Shebly, Abdalla A; El-kady, Mohamed A H; Hossain, M Yeamin

    2007-04-01

    An experiment was conducted to assess the potential of the European eel, Anguilla anguilla for earthen pond aquaculture without supplementary feeding at Lake Manzala, Egypt. Juvenile A. anguilla of mean length 11.7 cm and 2.4 g weight were stocked in earthen ponds measuring 3 feddans (about 12,600 m2) and 1 m deep. Stocking was done in May 2003 at a rate of 5000 fish feddan(-1) in a polyculture system including tilapia and mullets and fed mainly on natural occurring prey (natural spawned tilapia) and small shrimp. The eels were culture for a period of 2 years, May 2003 to April 2005. Sampling for growth and survival were evaluated yearly. At the end of the culture period, the gross weight of the harvested eels was measured and the net pond production calculated by the difference between weight stocked and weight harvested. Temperature varied from 11.5 to 28.2 degrees C and 12.2 to 29.3 degrees C; P(H), 7.3 to 8.9 and 7.5 to 8.8; Dissolved Oxygen (DO), 5.2 to 9.8 mg L(-1) and 4.1 to 8.3 mg L(-1); and Salinity, 2.5 to 5.5 psu and 3.0 to 6.8 psu for first year and second year, respectively. At the end of the culture period, A. anguilla attained average weight of 121.4 g fish(-1) at the end of the first year and a weight range of 152.5 to 430 g fish(-1) with an average of 280.36 g fish(-1) at the end of the second year. Survival rate ranged from 91% during the first year to 100% during the second year. Net eel production was 540.18 kg feddan(-1) at the end of the first year and 723.36 kg feddan(-1) at the end of the second year. Daily increments in weight per fish were 0.33 and 0.44 for first and second year, respectively. This experiment demonstrated the possibility of cultivation of eels as well as the higher growth rate in earthen ponds. The aquaculture strategy of eel with high stocking densities through low cost artificial feeds are recommended in future studies. PMID:19070049

  14. 1000 dams down and counting

    USGS Publications Warehouse

    O'Connor, James E.; Duda, Jeff J.; Grant, Gordon E.

    2015-01-01

    Forty years ago, the demolition of large dams was mostly fiction, notably plotted in Edward Abbey's novel The Monkey Wrench Gang. Its 1975 publication roughly coincided with the end of large-dam construction in the United States. Since then, dams have been taken down in increasing numbers as they have filled with sediment, become unsafe or inefficient, or otherwise outlived their usefulness (1) (see the figure, panel A). Last year's removals of the 64-m-high Glines Canyon Dam and the 32-m-high Elwha Dam in northwestern Washington State were among the largest yet, releasing over 10 million cubic meters of stored sediment. Published studies conducted in conjunction with about 100 U.S. dam removals and at least 26 removals outside the United States are now providing detailed insights into how rivers respond (2, 3).

  15. Tinnitus and its Risk Factors in the Beaver Dam Offspring Study

    PubMed Central

    Nondahl, David M; Cruickshanks, Karen J; Huang, Guan-Hua; Klein, Barbara EK; Klein, Ron; Nieto, F Javier; Tweed, Ted S

    2011-01-01

    OBJECTIVE To assess the prevalence of tinnitus along with factors potentially associated with having tinnitus. DESIGN Data were from the Beaver Dam Offspring Study, an epidemiological cohort study of aging. STUDY SAMPLE After a personal interview and audiometric examination, participants (n=3267, ages 21-84 years) were classified as having tinnitus if in the past year they reported having tinnitus of at least moderate severity or that caused difficulty in falling asleep. RESULTS The prevalence of tinnitus was 10.6%. In a multivariable logistic regression model adjusting for age and sex, the following factors were associated with having tinnitus: hearing impairment (Odds Ratio (OR) = 3.20), currently having a loud job (OR = 1.90), history of head injury (OR = 1.84), depressive symptoms (OR = 1.82), history of ear infection (men, OR = 1.75), history of target shooting (OR = 1.56), arthritis (OR = 1.46), and use of NSAID medications (OR = 1.33). For women, ever drinking alcohol in the past year was associated with a decreased risk of having tinnitus (OR = 0.56). CONCLUSIONS These results suggest that tinnitus is a common symptom in this cohort and may be associated with some modifiable risk factors. PMID:21309642

  16. A Study on the contribution of different food sources to shrimp growth in an intensive Fenneropenaeus chinensis pond

    NASA Astrophysics Data System (ADS)

    Su, Yuepeng; Ma, Shen; Tian, Xiangli; Dong, Shuanglin

    2008-11-01

    Stable isotope methods can be used to determine the food sources and prey items of aquatic organisms accurately and reliably. This study examined the relative contribution of artificial foods (the formulated feed and Artemia) and natural foods to shrimp growth in an intensive Fenneropenaeus chinensis pond by using carbon and nitrogen stable isotopes. The results showed that the nutrition utilization efficiency of the harvested shrimp was low, only 33.18% of feed nitrogen and 21.73% of feed carbon being converted to shrimp flesh. Our stable isotope results showed that the shrimp obtained nutrition for maximum growth from artificial foods, whose contribution was 93.5%, with the remaining attributed to the natural foods. However, there was 0.94 t harvested shrimp derived from natural foods (the rest of 13.56 t harvested shrimp derived from artificial foods) in 1ha intensive pond with a shrimp production of 14.50 t ha-1. Therefore, unit area shrimp production can be increased by increasing the contribution proportion of natural foods in intensive shrimp farming.

  17. Resource Conservation and Recovery Act corrective measures study: Area 6 decontamination pond facility, corrective action unit no. 92

    SciTech Connect

    1997-10-01

    Corrective Action Unit (CAU) No. 92, the Area 6 Decontamination Pond Facility (DPF), is an historic disposal unit located at the Nevada Test Site (NTS) in Nye County, Nevada (Figures 1 - 1, 1-2, and 1-3). The NTS is operated by the U.S. Department of Energy, Nevada Operations Office (DOE/NV), which has been required by the Nevada Division of Environmental Protection (NDEP) to characterize the DPF under the requirements of the Resource Conservation and Recovery Act (RCRA) Part A Permit (NDEP, 1995) for the NTS and Title 40 Code of Federal Regulations (CFR) Part 265 (1996c). The DPF is prioritized in the Federal Facility Agreement and Consent Order (FFACO, 1996) but is governed by the permit. The DPF was characterized through sampling events in 1994, 1996, and 1997. The results of these sampling events are contained in the Final Resource Conservation and Recovery Act Industrial Site Environmental Restoration Site Characterization Report, Area 6 Decontamination Pond Facility, Revision I (DOE/NV, 1997). This Corrective Measures Study (CMS) for the Area 6 DPF has been prepared for the DOE/NV`s Environmental Restoration Project. The CMS has been developed to support the preparation of a Closure Plan for the DPF. Because of the complexities of the contamination and regulatory issues associated with the DPF, DOE/NV determined a CMS would be beneficial to the evaluation and selection of a closure alternative.

  18. Influence of dams on sediment continuity: A study case of a natural metallic contamination.

    PubMed

    Frémion, Franck; Bordas, François; Mourier, Brice; Lenain, Jean-François; Kestens, Tim; Courtin-Nomade, Alexandra

    2016-03-15

    Sediments play an important role on the quality of aquatic ecosystems, notably in the reservoir areas where they can either be a sink or a source of contaminants, depending on the management and hydrological conditions. The physicochemical properties of 25 surface sediments samples of a reservoir catchment (Vaussaire, Cantal, France) were studied. Results show a strong influence of dam presence, notably on the grain size and organic matter (OM) contents. The concentrations of trace metals and metalloids (As, Cd, Cr, Cu, Ni, Pb and Zn) were also measured and compared with worldwide reservoir concentrations and international sediment quality guideline levels in order to assess the intensity of the metallic contamination. Cr and Ni are the trace elements presenting the significantly highest values at the catchment scale. Enrichment Factors (EF), calculated using both local and national backgrounds, show that metals have mainly a natural origin, explaining especially the Cr and Ni values, linked with the composition of parental rocks. Unexpectedly, all the observed metal concentrations are lower in the reservoir than upstream and downstream, which might be related to the high fresh OM inputs in the reservoir, diluting the global metallic contamination. Multivariate statistical analyses, carried out in order to identify the relationship between the studied metals and sediment characteristics, tend to support this hypothesis, confirming the unusually low influence of such poorly-degraded OM on trace element accumulation in the reservoir. PMID:26789366

  19. Studying and understanding the environmental impacts of the Three Gorges Dam in China

    NASA Astrophysics Data System (ADS)

    Schönbrodt-Stitt, Sarah; Stumpf, Felix; Schmidt, Karsten; Althaus, Paul; Bi, Renneng; Bieger, Katrin; Buzzo, Giovanni; Dumperth, Christian; Fohrer, Nicola; Rohn, Joachim; Strehmel, Alexander; Udelhoven, Thomas; Wei, Xiang; Zimmermann, Karsten; Scholten, Thomas

    2013-04-01

    network and early-warning system including local and regional authorities. Thus, the studies will contribute to a better understanding of the dimensions and dynamics of the ecological consequences of such large dam projects at the Yangtze River and worldwide.

  20. Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

    NASA Astrophysics Data System (ADS)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2015-08-01

    Beaver dams affect hydrologic processes, channel complexity, and stream temperature in part by inundating riparian areas, influencing groundwater-surface water interactions, and changing fluvial processes within stream systems. We explored the impacts of beaver dams on hydrologic and temperature regimes at different spatial and temporal scales within a mountain stream in northern Utah over a 3-year period spanning pre- and post-beaver colonization. Using continuous stream discharge, stream temperature, synoptic tracer experiments, and groundwater elevation measurements, we documented pre-beaver conditions in the first year of the study. In the second year, we captured the initial effects of three beaver dams, while the third year included the effects of ten dams. After beaver colonization, reach-scale (~ 750 m in length) discharge observations showed a shift from slightly losing to gaining. However, at the smaller sub-reach scale (ranging from 56 to 185 m in length), the discharge gains and losses increased in variability due to more complex flow pathways with beaver dams forcing overland flow, increasing surface and subsurface storage, and increasing groundwater elevations. At the reach scale, temperatures were found to increase by 0.38 °C (3.8 %), which in part is explained by a 230 % increase in mean reach residence time. At the smallest, beaver dam scale (including upstream ponded area, beaver dam structure, and immediate downstream section), there were notable increases in the thermal heterogeneity where warmer and cooler niches were created. Through the quantification of hydrologic and thermal changes at different spatial and temporal scales, we document increased variability during post-beaver colonization and highlight the need to understand the impacts of beaver dams on stream ecosystems and their potential role in stream restoration.

  1. An isotopic and chemical study of Lake Vanda and Don Juan Pond, Antarctica

    NASA Astrophysics Data System (ADS)

    Friedman, I.; Rafter, A.; Smith, G. I.

    Temperature measurements made in Lake Vanda and in the lake subbottom sediments show that the high temperatures in the lake are not due to geothermal heat flow, but are probably trapped solar energy. On the basis of Sr-87/86 ratios the salts in Lake Vanda can be derived by a mixture of 58% weathered rock plus 42% from sea water or precipitation. Loss of efflorescences high in sodium, potassium and magnesium by high winds can yield the salt compositions present in both Lake Vanda and Don Juan Pond. From isotopic data on deuterium, O-18, C-13, Sr-87/86, S-34 as well as from chemical data on Lake Vanda waters, interstitial brines contained in the subsurface sediment and C-14 dates a lake history is proposed.

  2. An ecosystem service approach to support integrated pond management: a case study using Bayesian belief networks--highlighting opportunities and risks.

    PubMed

    Landuyt, Dries; Lemmens, Pieter; D'hondt, Rob; Broekx, Steven; Liekens, Inge; De Bie, Tom; Declerck, Steven A J; De Meester, Luc; Goethals, Peter L M

    2014-12-01

    Freshwater ponds deliver a broad range of ecosystem services (ESS). Taking into account this broad range of services to attain cost-effective ESS delivery is an important challenge facing integrated pond management. To assess the strengths and weaknesses of an ESS approach to support decisions in integrated pond management, we applied it on a small case study in Flanders, Belgium. A Bayesian belief network model was developed to assess ESS delivery under three alternative pond management scenarios: intensive fish farming (IFF), extensive fish farming (EFF) and nature conservation management (NCM). A probabilistic cost-benefit analysis was performed that includes both costs associated with pond management practices and benefits associated with ESS delivery. Whether or not a particular ESS is included in the analysis affects the identification of the most preferable management scenario by the model. Assessing the delivery of a more complete set of ecosystem services tends to shift the results away from intensive management to more biodiversity-oriented management scenarios. The proposed methodology illustrates the potential of Bayesian belief networks. BBNs facilitate knowledge integration and their modular nature encourages future model expansion to more encompassing sets of services. Yet, we also illustrate the key weaknesses of such exercises, being that the choice whether or not to include a particular ecosystem service may determine the suggested optimal management practice. PMID:25005053

  3. Saturated solar ponds: 3. Experimental verification

    SciTech Connect

    Subhakar, D.; Murthy, S.S. )

    1994-12-01

    An experimental saturated solar pond is constructed using magnesium chloride salt. The temperature and concentration gradients are developed by heating the pond from the bottom and adding finely powdered salt from the top. The development of a temperature profile in the pond exposed to direct sunlight and its daily variation are studied. The predictions of the temperature profiles, using the authors' mathematical model, match the experiments better than the concentration profiles.

  4. Purification of Solar Ponds

    NASA Technical Reports Server (NTRS)

    Carpenter, S.

    1985-01-01

    Flocculatory agents added to solar saltponds remove turbidity to increase solar-energy collection efficiency. Flocculating agent or bacteriocide used to remove micro-organisms sprayed onto pond from airplane and allowed to settle to bottom of pond.

  5. Methods for noninvasive bathymetric and velocity surveys for impoundment safety--A case study of Herrington Lake at Dix Dam near Burgin, Kentucky

    USGS Publications Warehouse

    Ruby, A. Thomas, III

    2012-01-01

    The U.S. Geological Survey (USGS) created bathymetric-contour and water-velocity vector maps for portions of Lake Herrington within 600 feet of the face of Dix Dam near Burgin, Kentucky. The mapping was in support of a study of noninvasive acoustic technology for assessing structural integrity of dams, both as a routine inspection tool or as an emergency tool during hydrologic events, such as high water or flooding. In April 2010, scientists from the USGS used a boat-mounted transducer and echo sounder to obtain bathymetric data to characterize lakebed relief and sediment distribution under a closed-intake condition. Also in April 2010, an acoustic Doppler current profiler was employed to measure water velocity and flow direction in the lake to locate velocities moving toward the dam face and, possibly, dam leakage. The bathymetric survey showed the present condition of fill in the reservoir since the dam was completed, as well as provided an outline of the lake floor. The velocity survey indicated no discernible flow pattern or direction within the study area; only one transect had shown a difference from the others that was noticeable. The noninvasive acoustic bathymetric and velocity surveys used during the case study showed promise in locating potential dam or intake maintenance areas. Additional case studies throughout the Nation are needed to more clearly define whether the methods for noninvasive bathymetric and velocity surveys for dam safety will be successful in a variety of settings.

  6. Effect of beaver dams on the hydrology of small mountain streams: Example from the Chevral in the Ourthe Orientale basin, Ardennes, Belgium

    NASA Astrophysics Data System (ADS)

    Nyssen, J.; Pontzeele, J.; Billi, P.

    2011-05-01

    SummaryThe European beaver ( Castor fiber) was recently reintroduced to Belgium, after an absence of more than 150 years; around 120 beaver dam systems have been established. In Europe, few studies consider the hydrological effects of those dams, and the spatial scale larger than that of one beaver pond system has not been addressed at all. This research focuses on the hydrological effects of a series of six beaver dams on the Chevral R., a second order tributary of the Ourthe Orientale R. in a forested area of the Ardennes. Thereby, also the Ourthe Orientale sub-basin itself was taken into account, being the area with probably the highest density of beaver dams in Belgium. The main research questions regarded: (1) the extent to which discharge peaks are reduced at the very location and well downstream of beaver dams and (2) the impact of the beaver dams on low flows. The first approach consisted of a temporal analysis of the Ourthe Orientale discharge and precipitation data for the periods 1978-2003 (before) and 2004-2009 (after the establishment of beaver dams in the sub-basin). The second study determined the in situ impact of the beaver dams: discharges were measured (September 2009-March 2010) upstream as well as downstream of the 0.52 ha beaver dam system on the Chevral river, and changes in water level within the system of six dams were monitored. Our findings indicate that there is a significant lowering of discharge peaks in the downstream river reaches due to the effect of the beaver dams. The temporal analysis of the Ourthe Orientale sub-basin shows an increase in the recurrence interval for major floods; for instance, the recurrence interval of a reference flood of 60 m 3 s -1 increased from 3.4 years to 5.6 years since the establishment of the beaver dams. At the scale of the Chevral beaver dams' site, we measured that the dams top off the peak flows, in addition delaying them by approximately 1 day. There are also increased low flows: Q355 (i.e. the

  7. Waste Stabilization Ponds.

    ERIC Educational Resources Information Center

    Koundakjian, Philip

    This self-paced course contains reading assignments from a waste stabilization ponds operating manual, supportive text, example problems, and review questions, and a final examination. The course covers calculation of pond surface area, pond volume, organic load, detention time, drawdown, storage capacity, efficiency, and discharge. In addition,…

  8. Lagoons and Oxidation Ponds.

    ERIC Educational Resources Information Center

    O'Brien, W. J.

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers lagoons and oxidation ponds, and it includes some areas such as improving the effluents from ponds, stabilization ponds, aerated lagoons, and oxidation ditches. A list of 36 references is also presented. (HM)

  9. Intermediate pond sizes contain the highest density, richness, and diversity of pond-breeding amphibians.

    PubMed

    Semlitsch, Raymond D; Peterman, William E; Anderson, Thomas L; Drake, Dana L; Ousterhout, Brittany H

    2015-01-01

    We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes. PMID:25906355

  10. Intermediate Pond Sizes Contain the Highest Density, Richness, and Diversity of Pond-Breeding Amphibians

    PubMed Central

    Semlitsch, Raymond D.; Peterman, William E.; Anderson, Thomas L.; Drake, Dana L.; Ousterhout, Brittany H.

    2015-01-01

    We present data on amphibian density, species richness, and diversity from a 7140-ha area consisting of 200 ponds in the Midwestern U.S. that represents most of the possible lentic aquatic breeding habitats common in this region. Our study includes all possible breeding sites with natural and anthropogenic disturbance processes that can be missing from studies where sampling intensity is low, sample area is small, or partial disturbance gradients are sampled. We tested whether pond area was a significant predictor of density, species richness, and diversity of amphibians and if values peaked at intermediate pond areas. We found that in all cases a quadratic model fit our data significantly better than a linear model. Because small ponds have a high probability of pond drying and large ponds have a high probability of fish colonization and accumulation of invertebrate predators, drying and predation may be two mechanisms driving the peak of density and diversity towards intermediate values of pond size. We also found that not all intermediate sized ponds produced many larvae; in fact, some had low amphibian density, richness, and diversity. Further analyses of the subset of ponds represented in the peak of the area distribution showed that fish, hydroperiod, invertebrate density, and canopy are additional factors that drive density, richness and diversity of ponds up or down, when extremely small or large ponds are eliminated. Our results indicate that fishless ponds at intermediate sizes are more diverse, produce more larvae, and have greater potential to recruit juveniles into adult populations of most species sampled. Further, hylid and chorus frogs are found predictably more often in ephemeral ponds whereas bullfrogs, green frogs, and cricket frogs are found most often in permanent ponds with fish. Our data increase understanding of what factors structure and maintain amphibian diversity across large landscapes. PMID:25906355

  11. Sport fishery potential of power plant cooling ponds: Final report

    SciTech Connect

    Heidinger, R.C.; Lewis, W.M.

    1986-10-01

    This research was undertaken to determine if cooling ponds could serve as habitat for several coolwater fish species and also to evaluate the potential use of cooling ponds as nursery areas for receiving waters. The work was conducted on two cooling ponds in northern Illinois. Walleye (Stizostedion vitreum), muskellunge (Esox masquinongy), striped bass (Morone saxatilis) fingerlings, and adult threadfin shad (Dorosoma petenense) were stocked into both cooling ponds. The hybrids between the striped bass and white bass (M. chrysops) had been previously stocked into Collins Pond. Smallmouth bass (Micropterus dolomieui) fingerlings and larval striped bass and walleye were stocked in Dresden Pond. Several sampling techniques including seining, electrofishing, and rotenoning were used to monitor growth and survival of stocked species. In addition, escapement of stocked and indigenous species was monitored at the Dresden Pond spillway. Walleye, muskellunge, striped bass and hybrid striped bass exhibited excellent growth in Collins Pond as did smallmouth bass in Dresden Pond. One of the primary differences between an open system (such as Dresden Pond) and a closed system (such as Collins Pond) is the potential that the open system has to serve as a fish nursery area for receiving waters. The stocking of ''coolwater'' species in a closed type system such as Collins Pond is an effective way to control and maintain selected sport species. Dresden Pond was not open to public fishing during this study, but Collins Pond developed an excellent sport fishery as a result of these stockings.

  12. Measurements of radionuclide in Par Pond sediments with an underwater HPGe detector

    SciTech Connect

    Winn, W.G.

    1993-11-01

    Savannah River Site (SRS) effluent gamma emitting radionuclides in Par Pond sediment were examined in situ with an underwater HPGe detector prior to and following a 19 ft drawdown of the pond in 1991 to address dam repairs. These measurements provide a map of the {sup 137}Cs concentrations of the pond sediment, indicating that 9.4 {plus_minus} 1.5 Ci is exposed by the drawdown and that 46.6 {plus_minus} 7.2 Ci is the entire pond inventory. The highest individual {sup 137}Cs concentration was 25 {mu}Ci/m{sup 2} for the exposed sediment and 50 {mu}Ci/m{sup 2} for the entire pond. The results are consistent with parallel studies conducted by SREL, as well as historical data. Aside from {sup 137}Cs, the only other SRS-produced isotope observed was {sup 60}Co, with activity of only about 1% of that for {sup 137}Cs. This observation was also confirmed in grab samples of pond sediment and vegetation, which were returned to the laboratory for ultra-low-level gamma spectrometry analysis. A special effort was required to calibrate the underwater HPGe detector, where both measurements and calculational models were used. The effects of sediment depth profiles for density and {sup 137}Cs concentration were addressed in the calibration. Calibration factors for sediment surface concentrations ({mu}Ci/m{sup 2}/cpm) and sediment mass concentrations (pCi/kg/cpm) were obtained. In general, the {mu}Ci/m{sup 2}/cpm factor is recommended, as the pCi/kg/cpm factor depends on the depth location of the sediment of interest. However, a pCi/kg/cpm factor, which is dependent on the depth within the sediment is presented to address dose calculations that require it.

  13. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  14. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  15. Forebay Computational Fluid Dynamics Modeling for The Dalles Dam to Support Behavior Guidance System Siting Studies

    SciTech Connect

    Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.; Johnson, Gary E.

    2005-03-10

    Computational fluid dynamics (CFD) models were developed to support the siting and design of a behavioral guidance system (BGS) structure in The Dalles Dam (TDA) forebay on the Columbia River. The work was conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District (CENWP). The CFD results were an invaluable tool for the analysis, both from a Regional and Agency perspective (for the fish passage evaluation) and a CENWP perspective (supporting the BGS design and location). The new CFD model (TDA forebay model) included the latest bathymetry (surveyed in 1999) and a detailed representation of the engineered structures (spillway, powerhouse main, fish, and service units). The TDA forebay model was designed and developed in a way that future studies could easily modify or, to a large extent, reuse large portions of the existing mesh. This study resulted in these key findings: (1) The TDA forebay model matched well with field-measured velocity data. (2) The TDA forebay model matched observations made at the 1:80 general physical model of the TDA forebay. (3) During the course of this study, the methodology typically used by CENWP to contour topographic data was shown to be inaccurate when applied to widely-spaced transect data. Contouring methodologies need to be revisited--especially before such things as modifying the bathymetry in the 1:80 general physical model are undertaken. Future alignments can be evaluated with the model staying largely intact. The next round of analysis will need to address fish passage demands and navigation concerns. CFD models can be used to identify the most promising locations and to provide quantified metrics for biological, hydraulic, and navigation criteria. The most promising locations should then be further evaluated in the 1:80 general physical model.

  16. SOLPOND: a simulation program for salinity gradient solar ponds

    SciTech Connect

    Henderson, J.; Leboeuf, C.M.

    1980-01-01

    A computer simulation design tool was developed to simulate dynamic thermal performance for salinity gradient solar ponds. Dynamic programming techniques allow the user significant flexibility in analyzing pond performance under realistic load and weather conditions. Finite element techniques describe conduction heat transfer through the pond, earth, and edges. Results illustrate typical thermal performance of salinity gradient ponds. Sensitivity studies of salty pond thermal performance with respect to geometry, load, and optical transmission are included. Experimental validation of the program with an operating pond is also presented.

  17. Juvenile Radio-Tag Study: Lower Granite Dam, 1985 Annual Report.

    SciTech Connect

    Stuehrenberg, Lowell C.

    1986-06-01

    The concept of using mass releases of juvenile radio tags represents a new and potentially powerful research tool that could be effectively applied to juvenile salmonid passage problems at dams on the Columbia and Snake Rivers. A system of detector antennas, strategically located, would automatically detect and record individually tagged juvenile salmonids as they pass through the spillway, powerhouse, bypass system, or tailrace areas below the dam. Accurate measurements of spill effectiveness, fish guiding efficiency (FGE), collection efficiency (CE), spillway survival, powerhouse survival, and bypass survival would be possible without handling large numbers of unmarked fish. A prototype juvenile radio-tag system was developed and tested by the National Marine Fisheries Service (NMFS) and Bonneville Power Administration (BPA) at John Day Dam and at Lower Granite Dam. This report summarizes research to: (1) evaluate the effectiveness of the prototype juvenile radio-tag system in a field situation and (2) to test the basic assumptions inherent in using the juvenile radio tag as a research tool.

  18. Air demand estimation in bottom outlets with the particle finite element method - Susqueda Dam case study

    NASA Astrophysics Data System (ADS)

    Salazar, Fernando; San-Mauro, Javier; Celigueta, Miguel Ángel; Oñate, Eugenio

    2016-06-01

    Dam bottom outlets play a vital role in dam operation and safety, as they allow controlling the water surface elevation below the spillway level. For partial openings, water flows under the gate lip at high velocity and drags the air downstream of the gate, which may cause damages due to cavitation and vibration. The convenience of installing air vents in dam bottom outlets is well known by practitioners. The design of this element depends basically on the maximum air flow through the air vent, which in turn is a function of the specific geometry and the boundary conditions. The intrinsic features of this phenomenon makes it hard to analyse either on site or in full scaled experimental facilities. As a consequence, empirical formulas are frequently employed, which offer a conservative estimate of the maximum air flow. In this work, the particle finite element method was used to model the air-water interaction in Susqueda Dam bottom outlet, with different gate openings. Specific enhancements of the formulation were developed to consider air-water interaction. The results were analysed as compared to the conventional design criteria and to information gathered on site during the gate operation tests. This analysis suggests that numerical modelling with the PFEM can be helpful for the design of this kind of hydraulic works.

  19. High alpine ponds shift upwards as average temperatures increase: A case study of the Ortles-Cevedale mountain group (Southern Alps, Italy) over the last 50 years

    NASA Astrophysics Data System (ADS)

    Salerno, Franco; Gambelli, Sara; Viviano, Gaetano; Thakuri, Sudeep; Guyennon, Nicolas; D'Agata, Carlo; Diolaiuti, Guglielmina; Smiraglia, Claudio; Stefani, Fabrizio; Bocchiola, Daniele; Tartari, Gianni

    2014-09-01

    Alpine ecosystems are especially vulnerable to climate change, and lakes and ponds act as early indicators. Here, we describe our findings for the Ortles-Cevedale mountain group (Stelvio National Park, Southern Alps, Italy), where we used remote sensing to analyze more than 100 water ponds over the last 50 years (1954-2007). We found that since the 1980s, some lower elevation ponds (< 2500 m a.s.l.) have disappeared or experienced surface area reduction. We link this impact to the increased evaporation/precipitation ratio associated with climatic warming. At higher elevations (> 2900 m a.s.l.), we observed that since the 1950s, ponds have increased in size and that new ponds have appeared as a consequence of glacial shrinkage and retreat. However, these new ponds are ephemeral. The appearance of new environments is usually followed by their rapid disappearance and by a concomitant appearance of new ones, which is a clear sign of a transition from a glacial system to a paraglacial system. Surface area changes have been shown to be a highly visible and easily measurable signal of the impact of climate change on the alpine environment, as already demonstrated in other remote areas of the world. There is a clear need to extend this analysis to other sites in the Alps to gain a regional understanding of the phenomenon. The findings of this study make it possible to interpret the variations created by climate change in these environments, in terms of alteration of their ecological role and the loss of ecosystem services.

  20. Treatment efficiency of a wet detention pond combined with filters of crushed concrete and sand: a Danish full-scale study of stormwater.

    PubMed

    Sønderup, Melanie J; Egemose, Sara; Bochdam, Timm; Flindt, Mogens R

    2015-12-01

    Traditional wet detention ponds and sand filters remove particles efficiently, whereas only a minor part of the dissolved and bioavailable load is removed. To improve the retention of dissolved substances, we tested crushed concrete as a filter material simultaneously with a traditional sand filter placed after an existing wet pond. The particulate fractions (particles, organic matter, phosphorus, and heavy metals) were removed efficiently in the pond and both filter materials, with the concrete filter often being best seen over a year. Dissolved heavy metals (lead (Pb), nickel (Ni), copper (Cu), chromium (Cr), and cadmium (Cd)) were largely retained, though a washout was observed from the pond (Ni and Cu), concrete filter (Cr), and sand filter (Ni) during the first month. The pond only retained total dissolved phosphorus (TDP) during summer. Crushed concrete and sand had a high (>70%) retention of TDP within the first months of operation, but the retention dropped in both filters due to a large oil load into the system (4 kg impermeable ha(-1) in 1 month). The poor retention might to some degree be due to mineralization processes turning particulate phosphorus (PP) into TDP. The massive oil load was retained efficiently (99.3%) in the pond and both filters, clearly illustrating that both filter materials were able to retain either oil or TDP. An additional pilot study showed that at residence times of 1 h, crushed concrete bound 90% TDP whereas sand only bound 22% TDP. Retention of TDP and PP decreased with shorter residence time in both materials, but fastest in sand. PMID:26577218

  1. Event-based stormwater management pond runoff temperature model

    NASA Astrophysics Data System (ADS)

    Sabouri, F.; Gharabaghi, B.; Sattar, A. M. A.; Thompson, A. M.

    2016-09-01

    Stormwater management wet ponds are generally very shallow and hence can significantly increase (about 5.4 °C on average in this study) runoff temperatures in summer months, which adversely affects receiving urban stream ecosystems. This study uses gene expression programming (GEP) and artificial neural networks (ANN) modeling techniques to advance our knowledge of the key factors governing thermal enrichment effects of stormwater ponds. The models developed in this study build upon and compliment the ANN model developed by Sabouri et al. (2013) that predicts the catchment event mean runoff temperature entering the pond as a function of event climatic and catchment characteristic parameters. The key factors that control pond outlet runoff temperature, include: (1) Upland Catchment Parameters (catchment drainage area and event mean runoff temperature inflow to the pond); (2) Climatic Parameters (rainfall depth, event mean air temperature, and pond initial water temperature); and (3) Pond Design Parameters (pond length-to-width ratio, pond surface area, pond average depth, and pond outlet depth). We used monitoring data for three summers from 2009 to 2011 in four stormwater management ponds, located in the cities of Guelph and Kitchener, Ontario, Canada to develop the models. The prediction uncertainties of the developed ANN and GEP models for the case study sites are around 0.4% and 1.7% of the median value. Sensitivity analysis of the trained models indicates that the thermal enrichment of the pond outlet runoff is inversely proportional to pond length-to-width ratio, pond outlet depth, and directly proportional to event runoff volume, event mean pond inflow runoff temperature, and pond initial water temperature.

  2. ESTIMATING AMPHIBIAN OCCUPANCY RATES IN PONDS UNDER COMPLEX SURVEY DESIGNS

    EPA Science Inventory

    Monitoring the occurrence of specific amphibian species in ponds is one component of the US Geological Survey's Amphibian Monitoring and Research Initiative. Two collaborative studies were conducted in Olympic National Park and southeastern region of Oregon. The number of ponds...

  3. Simulation of Breach Outflow for Earthfill Dam

    NASA Astrophysics Data System (ADS)

    Razad, Azwin Zailti Abdul; Sabri Muda, Rahsidi; Mohd Sidek, Lariyah; Azia, Intan Shafilah Abdul; Hanum Mansor, Faezah; Yalit, Ruzaimei

    2013-06-01

    Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

  4. Comparative performance studies of water lettuce, duckweed, and algal-based stabilization ponds using low-strength sewage.

    PubMed

    Awuah, Esi; Oppong-Peprah, M; Lubberding, H J; Gijzen, H J

    A bench-scale continuous-flow wastewater treatment system comprising three parallel lines using duckweed (Spirodela polyrhiza), water lettuce (Pistia stratiotes), and algae (natural colonization) as treatment agents was set up to determine environmental conditions, fecal coliform profiles and general treatment performance. Each line consisted of four ponds connected in series fed by diluted sewage. Influent and effluent parameters measured included environmental conditions, turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrate, nitrite, ammonia, total phosphorus, fecal coliforms, mosquito larvae, and sludge accumulations. Environmental conditions and fecal coliforms profiles were determined in the sediments (0.63 m), suspensions (0.35 m), and surfaces (0.1 m) of each pond. Acidic conditions were observed in the pistia ponds, neutral conditions in duckweed ponds, and alkaline conditions in algal ponds. Fecal coliforms log removals of 6, 4, and 3 were observed in algal, duckweed, and pistia ponds, respectively, in the final effluents, with die-off rates per pond of 2.7, 2.0, and 1.6. Sedimentation accounted for over 99% fecal coliform removal in most of the algal and pistia ponds. BOD removal was highest in the duckweed system, followed by pistia and algae at 95%, 93%, and 25%, respectively. COD removals were 65% and 59%, respectively, for duckweed and pistia, while COD increased in algal ponds by 56%. Nitrate removals were 72%, 70%, and 36%, respectively for duckweed, pistia, and algal ponds. Total phosphorus removals were 33% and 9% for pistia and duckweed systems, while an increase of 19% was observed in the algal treatment system. Ammonia removals were 95% in both pistia and duckweed and 93% in algal systems. Removals of total dissolved solids (TDS) were 70% for pistia, 15% for duckweed, and 9% for algae. Mosquito populations of 11,175/m(2), 3516/m(2), and 96/m(2) were counted in pistia, algal, and duckweed ponds, respectively. Low

  5. NASA Ames DEVELOP Interns Collaborate with the South Bay Salt Pond Restoration Project to Monitor and Study Restoration Efforts using NASA's Satellites

    NASA Technical Reports Server (NTRS)

    Newcomer, Michelle E.; Kuss, Amber Jean; Nguyen, Andrew; Schmidt, Cynthia L.

    2012-01-01

    In the past, natural tidal marshes in the south bay were segmented by levees and converted into ponds for use in salt production. In an effort to provide habitat for migratory birds and other native plants and animals, as well as to rebuild natural capital, the South Bay Salt Pond Restoration Project (SBSPRP) is focused on restoring a portion of the over 15,000 acres of wetlands in California's South San Francisco Bay. The process of restoration begins when a levee is breached; the bay water and sediment flow into the ponds and eventually restore natural tidal marshes. Since the spring of 2010 the NASA Ames Research Center (ARC) DEVELOP student internship program has collaborated with the South Bay Salt Pond Restoration Project (SBSPRP) to study the effects of these restoration efforts and to provide valuable information to assist in habitat management and ecological forecasting. All of the studies were based on remote sensing techniques -- NASA's area of expertise in the field of Earth Science, and used various analytical techniques such as predictive modeling, flora and fauna classification, and spectral detection, to name a few. Each study was conducted by a team of aspiring scientists as a part of the DEVELOP program at Ames.

  6. Impact of beaver ponds on river discharge and sediment deposition along the Chevral River, Ardennes, Belgium

    NASA Astrophysics Data System (ADS)

    Nyssen, Jan; Frankl, Amaury; Pontzeele, Jolien; De Visscher, Maarten; Billi, Paolo

    2013-04-01

    With the recovery of the European beaver (Castor fiber) and their capacity to engineer fluvial landscapes, questions arise as to how they influence river discharge and sediment transport. The Chevral river (Ardennes, Belgium) contains two beaver dam sequences which appeared in 2004 and count now about 30 dams. Flow discharges and sediment fluxes were measured at the in- and outflow of each dam sequence. Volumes of sediment deposited behind the dams were measured. Between 2004 and 2011, peak flows were topped off, and the magnitude of extreme events decreased. 1710 m³ of sediment were deposited behind the beaver dams, with an average sediment thickness of 25 cm. The thickness of the sediment layer is related to the area of the beaver ponds. Along the stream, beaver pond sediment thickness displayed a sinusoidal deposition pattern, in which ponds with thick sediment layers were preceded by a series of ponds with thinner sediment layers. A downstream textural coarsening in the dam sequences was also observed, probably due to dam failures subsequent to surges. Differences in sediment flux between the in- and outflow at the beaver pond sequence were related to the river hydrograph, with deposition taking place during the rising limbs and slight erosion during the falling limbs. The seven-year-old sequences have filtered 190 tons of sediment out of the Chevral river, which is of the same order of magnitude as the 374 tons measured in pond deposits, with the difference between the values corresponding to beaver excavations (60 tons), inflow from small tributaries, and runoff from the valley flanks. Hydrogeomorphic effects of C. fiber and C. canadensis activity are similar in magnitude. The detailed analysis of changes to hydrology in beaver pond sequences confirms the potential of beavers to contribute to river and wetland restoration and catchment management.

  7. Interim results from a study of the behavior of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March--August 2011

    USGS Publications Warehouse

    Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.

    2012-01-01

    The movements and dam passage of yearling juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. A total of 411 hatchery fish and 26 wild fish were tagged and released between March 7 and May 21, 2011. A series of 16 autonomous hydrophones placed throughout the reservoir were used to determine general fish movements over the life of the acoustic transmitter, which was expected to be 91 days. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back. The dam passage rate was 11.2 percent (95-percent confidence interval 7.8–14.6 percent) for hatchery fish and 15.4 percent (95-percent confidence interval -1.0–31.8 percent) for wild fish within 91 days from release. Most fish passage occurred at night. The median time from release to dam passage was 34.5 days for hatchery fish and 34.2 days for wild fish. A system of hydrophones near the dam outlet, a temperature control tower, was used to estimate positions of fish in three dimensions to enable detailed analyses of fish behavior near the tower. Analyses of these data indicate that hourly averaged depths of fish within a distance of 74 m from the upstream face of the tower ranged from 0.6 to 9.6 meters, with a median depth of 3.6 meters for hatchery fish and 3.4 meters for wild fish. Dam discharge rates and the diurnal period affected the rates of dam passage. Rates of dam passage were similar when the dam discharge rate was less than 1,200 cubic feet per second, but increased sharply at higher discharges. The rate of dam passage at night was 4.4–7.8 times greater than during the day, depending on the distance of fish from the dam. This report is an interim summary of data collected as of August 3, 2011, for planning purposes.

  8. Rocky Flats Solar Evaporation Ponds RCRA hybrid-closure case study

    SciTech Connect

    Ogg, R.T.; Everett, L.G.; Cullen, S.J.

    1995-12-31

    The Solar Evaporation Ponds (SEP)/Operable Unit 4 (OU 4), located at the Rocky Flats Plant (RFP) sixteen miles northwest of Denver, Colorado, is currently undergoing remediation/Resource Conservation and Recovery Act (RCRA) closure in accordance with the Rocky Flats Interagency Agreement (IAG) signed by the US Department of Energy (DOE), US Environmental Protection Agency (EPA) and Colorado Department of Health (CDH) on January 22, 1991. Based on the Phase 1 (source and soils) RCRA Facility Investigation/Remedial Investigation (RFI/RI) data and interpretations, the DOE and EG and G Rocky Flats, Inc. (EG and G) have selected a permanent surface engineered/isolation barrier as the technological option for remediation of the SEP. The DOE and EG and G will utilize all natural materials to create an impermeable barrier/structure to isolate the waste being left in place from impacting human health and the environment for a minimum of 1,000 years. The rationale for utilizing natural materials is two fold; (1) optimize long term performance of the barrier and; (2) design a structure which will be near maintenance free (passive remediation) for 1,000 years. The DOE and EG and G have taken a proactive approach in providing post closure performance assessment for this RCRA closure action. An integrated monitoring system has been designed which will include monitoring the engineered barrier, vadose zone and ground water systems. Rocky Flats will integrate instrumentation, into the permanent engineered barrier which will provide early warning of potential liquid migration through the barrier and into the waste zone.

  9. Rocky Flats Solar Evaporation Ponds RCRA hybrid-closure case study

    SciTech Connect

    Ogg, R.T.; Everett, L.G.; Cullen, S.J.

    1994-12-31

    The Solar Evaporation Ponds (SEP)/Operable Unit 4 (OU 4), located at the Rocky Flats Plant (RFP) sixteen miles northwest of Denver, Colorado, is currently undergoing remediation/Resource Conservation and Recovery Act (RCRA) closure in accordance with the Rocky Flats Interagency Agreement (IAG) signed by the US Department of Energy (DOE), US Environmental Protection Agency (EPA) and Colorado Department of Health (CDH) on January 22, 1991. Based on the ``Phase 1`` (source and soils) RCRA Facility Investigation/Remedial Investigation (RFM data and interpretations), the DOE and EG and G Rocky Flats, Inc. (EG and G) have selected a permanent surface engineered/isolation barrier as the technological option for remediation of the SEP. The DOE and EG and G will utilize all natural materials to create an ``impermeable`` barrier/structure to isolate the waste being left in place from impacting human health and the environment for a minimum of 1,000 years. Their rationale for utilizing natural materials is two fold; (1) optimize long term performance of the barrier and; (2) design a structure which will be near maintenance free (passive remediation) for 1,000 years. The DOE and EG and G have taken a proactive approach in providing post closure performance assessment for this RCRA closure action. An integrated monitoring system has been designed which will include monitoring the engineered barrier, vadose zone and ground water systems. Rocky Flats will integrate instrumentation into the permanent engineered barrier which will provide early warning of potential liquid migration through the barrier and into the waste zone.

  10. Bacterial Bioaugmentation of Channel Catfish Ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve, 0.1-ha earthen ponds at Stoneville, Mississippi were used in a 2-year, double-blind study of the effects of a Bacillus-based bacterial bioaugmentation product on water quality and production of channel catfish Ictalurus punctatus. Each year, six ponds were treated weekly with the microbial p...

  11. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned.

  12. Effects of urbanization on three ponds in Middleton, Wisconsin

    USGS Publications Warehouse

    House, Leo B.

    1984-01-01

    A digital hydrologic model was used to simulate the effects of future residential development on pond inflow volumes and resulting water levels of three ponds in Middleton, Wisconsin. The model computed the daily water budget and the resulting water level for each pond. The results of the model calibration are presented in the report, along with the existing watershed hydrologic conditions and runoff volumes for the 1982 study period. Data was collected during 1982 to claibrate the model; the data included pond stage, ground-water levels, precipitation and other meteorological characteristics. In addition, water-quality samples were collected at each pond to characterize the water quality. Simulation of pond levels with the 1982 rainfall and fully developed watersheds did not result in stages greater than those observed in 1982. Simulation of pond levels with rainfall having a 20-year recurrence interval (1978) and hypothetical, fully developed watersheds resulted in maximum pond stages above those observed in 1982. Peak stage of Tiedeman 's Pond would increase by 2.77 feet, Stricker 's Pond by 3.91 feet, and Esser 's Pond by 1.44 feet. Simulation of pond levels with an estimated 100-year rainfall and hyopthetical, fully developed watersheds would result in peak stage increases of 5.30, 5.32, and 1.97 feet above the peak 1982 observed stages for Tiedeman's, Stricker's, and Esser 's Ponds, respectively. (USGS)

  13. Malaria and the Narmada-river development in India: a case study of the Bargi dam.

    PubMed

    Singh, N; Mehra, R K; Sharma, V P

    1999-07-01

    The largest river-valley development to be proposed in India is that in the Narmada valley. The building of the Bargi dam, a multi-purpose irrigation and hydro-electric project, in Jabalpur, in central India, formed part of the first phase of the development of this valley (1974-1988). Many villages and several hectares of land in three districts were submerged as the waters rose behind the dam, the worst affected area being the catchment area of the primary health centre (PHC) at Narayanganj, in Mandla district. Until recently, cases of malaria were relatively rare in Narayanganj. However, an epidemic of malaria in late 1996 claimed hundreds of lives in the area and the outbreak spread, during 1997, to new villages in the region. A review of the records collected by the National Malaria Eradication Programme (NMEP) not only indicated that the slide positivity rate (SPR) for Narayanganj increased > 7.45-fold between 1979 and 1997 but also that the slide falciparum rate (SFR) increased > 32-fold over the same period. The NMEP data available for Mandla district as a whole indicated a doubling in mean SPR and SFR between 1979 and 1997. There is no evidence that a new species of vector has established since 1979. In fact, indoor-resting densities of anophelines and of the most established vector, Anopheles culicifacies, have fallen since the dam was built, but densities of another vector, An. fluviatilis, have increased. PMID:10690243

  14. Economic Efficiency and Equity in Dams Removal: Case studies in Northeastern Massachusetts Doina Oglavie, Ellen Douglas, David Terkla

    NASA Astrophysics Data System (ADS)

    Oglavie, D. R.; Douglas, E. M.; Terkla, D.

    2009-12-01

    According to American Rivers (www.americanrivers.org), Massachusetts has almost 3,000 dams under state regulation, 296 of which have been classified as high hazard, meaning they pose a serious threat to human life if they should fail. Most of these dams, however, are low head, “run-of-the-river” dams that no longer serve the purpose for which they were built. The presence of these dams has fragmented aquatic and riparian ecosystems, impeded fish passage and generally impacted the natural ecological and hydrological functioning of the streams in which they reside. Dam removal should be considered when a dam no longer serves its function. Although in many cases, the removal of a dam is environmentally beneficial (at least over the long term), sometimes the removal of a dam can incur environmental costs, such as release of contaminants that were sequestered behind the dam. Dam removal is a complex issue especially with respect to privately owned dams. In many cases, dam removal is less costly than dam maintenance or upgrade, hence dam removal decisions tend to be based on purely monetary considerations, and the environmental costs or benefits associated with the dam are not considered. Typically, the main objective for the dam owner is to incur the lowest possible cost (private cost), whether it be operating and maintenance or removal; external costs (environmental degradation) are rarely, if ever, considered, hence the true cost to society is not included in the economic analysis. If dam operation and removal decisions are to be economically efficient, then they have to include both the private costs as well as the external (environmental) costs. The purpose of this work is to 1) attempt to quantify the externalities associated with the maintenance and the removal of dams, 2) assess whether or not the current dam removal evaluation process maximizes social welfare (efficiency and equity) and 3) suggest ways in which this process can be improved by including the

  15. Carotid Intima Media Thickness, Atherosclerosis, and 5-Year Decline in Odor Identification: The Beaver Dam Offspring Study

    PubMed Central

    Cruickshanks, Karen J.; Fischer, Mary E.; Huang, Guan-Hua; Klein, Ronald; Tsai, Michael Y.; Pinto, A. Alex

    2015-01-01

    Background. The purpose of this study was to determine if subclinical markers of atherosclerosis are associated with a decline in olfactory function. Methods. The San Diego Odor Identification Test was administered to 2,302 participants (age 21–84 years) at the baseline (2005–2008) and 5-year follow-up (2010–2013) examinations of the Beaver Dam Offspring Study. A decline in odor identification was defined as a decrease in San Diego Odor Identification Test score of 2 or more (range 0–8) from Beaver Dam Offspring Study 1 to Beaver Dam Offspring Study 2. Carotid intima media thickness and plaque, blood pressure, pulse wave velocity, and body mass index were measured and other risk factor data were obtained by interview. Results. Overall 3.2% of participants had a decline in San Diego Odor Identification Test score at 5 years. In age- and sex-adjusted models, mean intima media thickness (odds ratio = 1.17, 95% CI = 1.01, 1.34, per 0.1 mm) and number of sites (range 0–6) with carotid artery plaque (odds ratio = 1.35, 95% CI = 1.11, 1.65, per site) at baseline were associated with an increased risk for decline. Plaque score (odds ratio = 1.24, 95% CI = 1.01, 1.53) remained a significant independent predictor of olfactory decline in a model that included age, sex, hypertension, body mass index, alcohol, and smoking. Conclusions. Subclinical atherosclerosis was associated with an increased risk for olfactory decline indicating that atherosclerosis may be one of the risk factors for the decline in olfactory function seen with aging. Strategies to improve vascular health may also benefit olfactory health. PMID:25182599

  16. Big Fish in a Big Pond: a study of academic self concept in first year medical students

    PubMed Central

    2011-01-01

    Background Big-fish-little-pond effect (BFLPE) research has demonstrated that students in high-ability environments have lower academic self-concepts than equally able students in low-ability settings. Research has shown low academic self-concepts to be associated with negative educational outcomes. Social comparison processes have been implicated as fundamental to the BFLPE. Methods Twenty first-year students in an Australian medical school completed a survey that included academic self-concept and social comparison measures, before and after their first written assessments. Focus groups were also conducted with a separate group of students to explore students' perceptions of competence, the medical school environment, and social comparison processes. Results The quantitative study did not reveal any changes in academic self-concept or self-evaluation. The qualitative study suggested that the attributions that students used when discussing performance were those that have been demonstrated to negatively affect self-concept. Students reported that the environment was slightly competitive and they used social comparison to evaluate their performance. Conclusions Although the BFLPE was not evident in the quantitative study, results from the qualitative study suggest that the BFLPE might be operating In that students were using attributions that are associated with lower self-concepts, the environment was slightly competitive, and social comparisons were used for evaluation. PMID:21794166

  17. A framework for social impact analysis of large dams: a case study of cascading dams on the Upper-Mekong River, China.

    PubMed

    Wang, Pu; Lassoie, James P; Dong, Shikui; Morreale, Stephen J

    2013-03-15

    Construction of large dams on the Upper-Mekong River, China, has significant social impacts on local communities. To analyze the social impacts, we identified three classes of wealth for the affected people, material, embodied, and relational, and comprehensively compared the loss and compensation in each type of wealth. Then we examined the effects on gap of wealth at household and community levels. Lastly, an insider-outsider analysis was conducted to understand the differences in the perceptions of wealth loss between local villagers and policy makers, and recommendations for more reasonable compensation policies were provided. PMID:23380304

  18. Nonlinear Seismic Analysis of Morrow Point Dam

    SciTech Connect

    Noble, C R; Nuss, L K

    2004-02-20

    This research and development project was sponsored by the United States Bureau of Reclamation (USBR), who are best known for the dams, power plants, and canals it constructed in the 17 western states. The mission statement of the USBR's Dam Safety Office, located in Denver, Colorado, is ''to ensure Reclamation dams do not present unacceptable risk to people, property, and the environment.'' The Dam Safety Office does this by quickly identifying the dams which pose an increased threat to the public, and quickly completing the related analyses in order to make decisions that will safeguard the public and associated resources. The research study described in this report constitutes one element of USBR's research and development work to advance their computational and analysis capabilities for studying the response of dams to strong earthquake motions. This project focused on the seismic response of Morrow Point Dam, which is located 263 km southwest of Denver, Colorado.

  19. The Impact of Natural Hydrologic Variability on the Accuracy of Remote Sensing Pond Surface Area Change Detection Studies Within the Canadian Subarctic

    NASA Astrophysics Data System (ADS)

    Parrott, J. A.; Macrae, M. L.; Duguay, C. R.

    2009-12-01

    Within the sub-arctic environment, shallow ponds occupy 15-50% of the landscape and strongly contribute to regional hydrological and energy budgets. Given the unique hydrological environment in which they reside, ponds may be good indicators of regional environmental or climatic change. Therefore, accurately delineating and detecting surface area changes within these shallow water features is crucial when understanding the regional impacts of shifting climatic conditions. Recent remote sensing studies have revealed disparate results related to the long-term sustainability of sub-arctic shallow water features. However, many of these studies have not considered the impact of naturally induced hydrologic variability on the accuracy of change detection results. The overall objective of this study was to determine the impact of various environmentally driven hydrologic fluctuations on the ability for remotely sensed images to accurately capture pond surface area and detect change within the sub-arctic. Specifically, this study aimed to determine the influence of (a) inter-seasonal water balance fluctuations (b) antecedent precipitation prior to image acquisition and (c) anomalous annual climate (drought) on the quality of remote sensing studies focused on detecting long-term pond surface area change within the Hudson Bay Lowlands, near Churchill. The objectives were addressed using a combination of methods including climate data, field research, simple water balance modeling and remote sensing imagery. Specifically, a subset of 37 ponds, ranging in size from 918m2 to 34,624m2, were digitized and compared in order to detect surface area change linked to inter-seasonal hydrologic variability (two 1956 air photos), varying antecedent rainfall prior to acquisition dates (2000 and 2001 Landsat 7 images) and normal verses drought conditions (2000 Landsat 7 and 2006 SPOT images). Results from the imagery analyses were linked to climate data and a simple water balance model

  20. 28. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. Bridge over intake trough, gate in background behind bridge. South 170 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  1. 31. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. Gate, wind walls, covered trough, bridge in background. North/northwest 330 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  2. 33. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. View from flume (Photographer standing in flume). Note wide flume mouth, covered trough, gate, bridge in background. South/southwest 160 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  3. 30. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. View through gate, covered trough on other side of gate leading to flume in distance. South 200 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  4. 32. At Willard, Little Salmon Creek. Site of former dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. At Willard, Little Salmon Creek. Site of former dam and water supply pond for Broughton flume. View looking down flume at transition from covered trough to flume (covered trough is approximately 75'). South 180 degrees. - Broughton Flume, Hood River Junction on Columbia River at Washington/Oregon border, Hood, Skamania County, WA

  5. 4. Aerial view southwest, Adams Dam Road bottom left, State ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Aerial view southwest, Adams Dam Road bottom left, State Route 100 center, back gates to Winterthur and Wilmington Country Club upper center, duck pond and reservoir bottom right and center, and State Route 92 center bottom. - Winterthur Farms, Intersection State Routes 92 & 100, Intersection State Routes 92 & 100, Winterthur, New Castle County, DE

  6. 5. Aerial view west, Adams Dam Road bottom center, State ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Aerial view west, Adams Dam Road bottom center, State Route 100 center, duck pond and reservoir center, State Route 100 center right, State Route 92 below center right, Brandywine Creek State Park center bottom. - Winterthur Farms, Intersection State Routes 92 & 100, Intersection State Routes 92 & 100, Winterthur, New Castle County, DE

  7. 1. VIEW OF THE MILL TAILINGS FACING NORTHWEST. SEDIMENT DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF THE MILL TAILINGS FACING NORTHWEST. SEDIMENT DAM AND POND IN THE FOREGROUND, AND WATER PUMP (FEATURE B-25) ON THE LOWER RIGHT SIDE OF PHOTO. - Nevada Lucky Tiger Mill & Mine, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  8. Self-Reported Hearing Difficulties Among Adults With Normal Audiograms: The Beaver Dam Offspring Study

    PubMed Central

    Tremblay, Kelly L.; Pinto, Alex; Fischer, Mary E.; Klein, Barbara E. K.; Klein, Ronald; Levy, Sarah; Tweed, Ted S.; Cruickshanks, Karen J.

    2016-01-01

    Objective Clinicians encounter patients who report experiencing hearing difficulty (HD) even when audiometric thresholds fall within normal limits. When there is no evidence of audiometric hearing loss, it generates debate over possible biomedical and psychosocial etiologies. It is possible that self-reported HDs relate to variables within and/or outside the scope of audiology. The purpose of this study is to identify how often, on a population basis, people with normal audiometric thresholds self-report HD and to identify factors associated with such HDs. Design This was a cross-sectional investigation of participants in the Beaver Dam Offspring Study. HD was defined as a self-reported HD on a four-item scale despite having pure-tone audiometric thresholds within normal limits (<20 dB HL0.5, 1, 2, 3, 4, 6, 8 kHz bilaterally, at each frequency). Distortion product otoacoustic emissions and word-recognition performance in quiet and with competing messages were also analyzed. In addition to hearing assessments, relevant factors such as sociodemographic and lifestyle factors, environmental exposures, medical history, health-related quality of life, and symptoms of neurological disorders were also examined as possible risk factors. The Center for Epidemiological Studies-Depression was used to probe symptoms associated with depression, and the Medical Outcomes Study Short-Form 36 mental score was used to quantify psychological stress and social and role disability due to emotional problems. The Visual Function Questionnaire-25 and contrast sensitivity test were used to query vision difficulties. Results Of the 2783 participants, 686 participants had normal audiometric thresholds. An additional grouping variable was created based on the available scores of HD (four self-report questions), which reduced the total dataset to n = 682 (age range, 21–67 years). The percentage of individuals with normal audiometric thresholds who self-reported HD was 12.0% (82 of 682). The

  9. Suitable Site Selection of Small Dams Using Geo-Spatial Technique: a Case Study of Dadu Tehsil, Sindh

    NASA Astrophysics Data System (ADS)

    Khalil, Zahid

    2016-07-01

    Decision making about identifying suitable sites for any project by considering different parameters, is difficult. Using GIS and Multi-Criteria Analysis (MCA) can make it easy for those projects. This technology has proved to be an efficient and adequate in acquiring the desired information. In this study, GIS and MCA were employed to identify the suitable sites for small dams in Dadu Tehsil, Sindh. The GIS software is used to create all the spatial parameters for the analysis. The parameters that derived are slope, drainage density, rainfall, land use / land cover, soil groups, Curve Number (CN) and runoff index with a spatial resolution of 30m. The data used for deriving above layers include 30 meter resolution SRTM DEM, Landsat 8 imagery, and rainfall from National Centre of Environment Prediction (NCEP) and soil data from World Harmonized Soil Data (WHSD). Land use/Land cover map is derived from Landsat 8 using supervised classification. Slope, drainage network and watershed are delineated by terrain processing of DEM. The Soil Conservation Services (SCS) method is implemented to estimate the surface runoff from the rainfall. Prior to this, SCS-CN grid is developed by integrating the soil and land use/land cover raster. These layers with some technical and ecological constraints are assigned weights on the basis of suitability criteria. The pair wise comparison method, also known as Analytical Hierarchy Process (AHP) is took into account as MCA for assigning weights on each decision element. All the parameters and group of parameters are integrated using weighted overlay in GIS environment to produce suitable sites for the Dams. The resultant layer is then classified into four classes namely, best suitable, suitable, moderate and less suitable. This study reveals a contribution to decision making about suitable sites analysis for small dams using geo-spatial data with minimal amount of ground data. This suitability maps can be helpful for water resource

  10. Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

    PubMed Central

    Kuzishchin, Kirill V.; Stanford, Jack A.

    2016-01-01

    Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3–12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99–1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically

  11. Trapping efficiency of three types check dams experiment

    NASA Astrophysics Data System (ADS)

    Huang, Hui-Kai; CHEN, Su-Chin; AN, Hsuan-Pei

    2015-04-01

    The check dams constructed to trap debris flow. This study divide check dams into three types as closed-type check dam, slit dam, and modular steel check dam. Closed-type check dam which can trap all kind of sediment or driftwood. Slit check dam is permeable dam, so it can prevent from depositing all of sediment or driftwood. A modular steel check dam improves the existing hard-to-change disadvantages of slit dam structure. The assembling of longitudinal and transverse beams can be constructed independently, and then it could be freely configured to form a flexibly adjustable modular steel check dam. This study used the laws of geometric similitude to design model of dam. To explore the trapping mechanisms and phenomenon in different dismantle transverse beams conditions and compared the trapping efficiency with different type of check dams. This study used different volume ratio with driftwood and sediment. In order to capture the trace of debris flow and calculate accuracy velocity of debris flow the study used several high-speed photography combining the method of 3D Remodeling from Motion Structure with Multi-View Stereo which constructed with multiple photos of overlapping coefficient at least 70% and established three-dimensional system of coordinate in laboratory experiment. As a result, the driftwood deposition rate of modular steel check dam increase 60% than slit dam and 40% than closed-type dam; the debris deposition rate increase 30% than slit dam. In addition, the increment of driftwood volume ratio led to the increment of trapping efficiency of three type of check dams. Meanwhile slit dam is the most effective type in trapping driftwood and sediment with more than 50% of increased rate, because of more driftwood flow through the slit dam jam together easily. Finally, transverse beams which installed the modular steel check dam can suppress the upward movement of driftwood, therefore driftwood can easily form the arched stacking efficiency with

  12. The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    USGS Publications Warehouse

    Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Smith, Lacy M.; Moskal, Stacy M.; De La Cruz, Susan E. W.; Yee, Julie L.; Takekawa, John Y.

    2014-01-01

    The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populations, the South Bay Salt Pond Restoration Project plans to create new islands within former salt ponds in South San Francisco Bay. In a series of studies, we investigated pond and individual island attributes that are most beneficial to nesting, foraging, and roosting waterbirds.

  13. Waste Characteristics of the Former S-3 Ponds and Outline of Uranium Chemistry Relevant to NABIR Field Research Center Studies

    SciTech Connect

    Brooks, S.C.

    2001-06-29

    The Environmental Sciences Division at Oak Ridge National Laboratory (ORNL) was awarded the first Naturaland Accelerated Bioremediation Research (NABIR) Program, Field Research Center (FRC) based upon the recommendation of a review panel following a competitive peer-reviewed proposal process. The contaminated FRC site at ORNL is centered on groundwater plumes that originate from the former S-3 Waste Disposal Ponds located at the Y-12 Plant and the Y-12 Bone Yard/Bum Yard. Proposals for individual science research projects at the FRC were submitted in the spring of 2000 in response to a solicitation issued by the Department of Energy (DOE). Proposals selected for funding began work in Fiscal Year 2001 (October 1, 2000). The FRC staff have initiated several characterization efforts intended to support, inform, and educate individual FRC investigators, NABIR principal investigators (PIs), and the broader community of the specific conditions, opportunities, and challenges of this site. These efforts include both physical site characterization as well as numerical simulation (modeling) studies. Geochemical modeling has been conducted with the goal of: (1) providing a baseline understanding of the geochemical behavior of uranium (U); (2) examining the interaction of geochemistry and uranium transport in the subsurface; (3) elucidating some potential pitfalls for researchers with respect to manipulating subsurface environments for the purpose of demonstrating bacterially induced U immobilization. The geochemical modeling effort focused on using existing data and resources and did not involve the collection of new data or samples from the field site. Specifically, the following three tasks have been performed to date. (1) Searching for information on the wastes disposed in to the S-3 ponds. These data are typically found in internal technical reports at the labs and are rarely published in the peer-reviewed literature; thus, this information can be very difficult for the

  14. Toxic and accumulative potential of the antifouling biocide and TBT successor irgarol on freshwater macrophytes: a pond mesocosm study.

    PubMed

    Mohr, Silvia; Berghahn, Rüdiger; Mailahn, Wolfgang; Schmiediche, Ronny; Feibicke, Michael; Schmidt, Ralf

    2009-09-01

    After the ban of tributyltin (TBT) for vessels not longer than 25 m in 1986, Irgarol has become a commonly used antifouling biocide. Irgarol is highly toxic to autotrophic organisms and has the potential to accumulate in organic material. In the literature, environmental concentrations of Irgarol up to 2.4 microg L(-1) were reported forfreshwater. Within a comprehensive freshwater mesocosm study, experiments were conducted to gain more information on the effects of Irgarol on macrophytes. Six indoor pond mesocosms were contaminated once with concentrations between 0.04 and 5 microgl(-1) Irgarol and monitored for 150 days; two mesocosms served as controls. The mesocosm study revealed that all macrophytes were directly affected by this single application. Myriophyllum verticillatum was the most sensitive macrophyte with an EC50 (Day 150) of 0.21 microg L(-1) Irgarol. The duckweed Spirodela polyrhiza was the least sensitive species tested in the mesocosms and number of fronds even increased with increasing Irgarol concentrations. Time-weighted average calculations yielded high BCF values of up to 10,580 L kg(-1) dry weight for M. verticillatum indicating a high potential for accumulation. The results give cause for concern that natural macrophyte communities are impaired at actual environmental concentrations. PMID:19764257

  15. Laboratory study of the clogging process and factors affecting clogging in a tailings dam

    NASA Astrophysics Data System (ADS)

    Wu, Jun; Wu, Yanqing; Lu, Jian

    2008-05-01

    Laboratory simulation of clogging in the Lixi tailings dam (Shaanxi Province, China) is urgently required because clogging is an important factor affecting the dam stability. This work firstly presents the results of ferrous iron oxidation experiments using buffer solution. The results indicate that the ferrous iron oxidation follows first order kinetics, and the oxidation process is strongly dependent on pH, a higher pH resulting in a higher oxidation rate. Furthermore, when the pH exceeds 7.0, the oxidation rate constant increases significantly. Secondly, a column experiment was carried out under the conditions of the pH ranging from 6.8 to 7.5 and the natural oxygen supply. Ferrous iron oxidation and precipitation were found to reach equilibrium under these conditions. After 23 days, the column experiment was stopped when the clogging materials blocked the column outlet. The clogging materials were found to be a mixture of ferric hydroxide and its converted products, and these existed in amorphous form with a loose cluster microstructure according to the results of XRD and SEM.

  16. Particle Clogging in Filter Media of Embankment Dams: A Numerical and Experimental Study

    NASA Astrophysics Data System (ADS)

    Antoun, T.; Kanarska, Y.; Ezzedine, S. M.; Lomov, I.; Glascoe, L. G.; Smith, J.; Hall, R. L.; Woodson, S. C.

    2013-12-01

    The safety of dam structures requires the characterization of the granular filter ability to capture fine-soil particles and prevent erosion failure in the event of an interfacial dislocation. Granular filters are one of the most important protective design elements of large embankment dams. In case of cracking and erosion, if the filter is capable of retaining the eroded fine particles, then the crack will seal and the dam safety will be ensured. Here we develop and apply a numerical tool to thoroughly investigate the migration of fines in granular filters at the grain scale. The numerical code solves the incompressible Navier-Stokes equations and uses a Lagrange multiplier technique which enforces the correct in-domain computational boundary conditions inside and on the boundary of the particles. The numerical code is validated to experiments conducted at the US Army Corps of Engineering and Research Development Center (ERDC). These laboratory experiments on soil transport and trapping in granular media are performed in constant-head flow chamber filled with the filter media. Numerical solutions are compared to experimentally measured flow rates, pressure changes and base particle distributions in the filter layer and show good qualitative and quantitative agreement. To further the understanding of the soil transport in granular filters, we investigated the sensitivity of the particle clogging mechanism to various parameters such as particle size ratio, the magnitude of hydraulic gradient, particle concentration, and grain-to-grain contact properties. We found that for intermediate particle size ratios, the high flow rates and low friction lead to deeper intrusion (or erosion) depths. We also found that the damage tends to be shallower and less severe with decreasing flow rate, increasing friction and concentration of suspended particles. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under

  17. Summary of juvenile salmonid passage and survival at McNary Dam-Acoustic survival studies, 2006-09

    USGS Publications Warehouse

    Adams, Noah S.; Evans, Scott D.

    2011-01-01

    Passage and survival data were collected at McNary Dam between 2006 and 2009. These data have provided critical information for resource managers to implement structural and operational changes designed to improve the survival of juvenile salmonids as they migrate past the dam. Given the importance of these annual studies, the primary objectives of this report were to summarize the findings of these annual studies to ensure that passage and survival metrics are consistently calculated and reported across all years and to consolidate this information in a single document, thereby making it easier to reference. It is worth noting that this report does not contain all the information from all the annual reports. The intent of this report was to summarize the key findings from multiple years of research. The reader is encouraged to reference the annual reports if more detailed information is needed. Chapter 1 summarizes existing behavior, passage, and survival results for fish released 10 rkm upstream of McNary Dam and from the McNary Dam tailrace during 2006-09. Chapter 2 summarizes existing behavior, passage, and survival results for fish released in the mid-Columbia River and detected at McNary Dam during 2006-09. Results from 2006 indicated that higher spill discharge generally resulted in higher fish passage through spill, and in turn, higher fish survival through the entire dam. Within the spillway, passage effectiveness was highest for the south spill bays, adjacent to the powerhouse. Increased passage in this area, combined with detailed 3-dimensional approach paths, aided in the design and location of the temporary spillway weirs (TSWs) at McNary Dam prior to the 2007 migration of juvenile salmonids. During the 2007 study, the TSWs were tested under two spill treatments during the spring and summer: a "2006 Modified spill," and a "2007 test spill." In the spring, slightly higher discharge through spill bays 14-17 was the primary difference between the spill

  18. Juvenile Radio-Tag Study: Lower Granite Dam, 1985-1986 Final Report.

    SciTech Connect

    Giorgi, Albert E.

    1988-03-01

    A prototype juvenile radio-tag system was developed and tested by the National Marine Fisheries Services (NMFS) and Bonneville Power Administration (BPA) at John Day Dam in 1984. Results indicated that the system could provide acceptable estimates of powerhouse and spillway passage. Research in 1986 continued testing of the tag system to further define its application and limitations. Field work included releases in the forebay and tailrace under a no-spill environment and testing of new systems to improve tag detection. Laboratory tests included the response of the tag in hostile environmental conditions (spillway passage) and the effects of the radio tag on fish buoyancy compensation. This report provides results of the work along with a summarization of the combined 1985--86 field and assumption testing. 12 refs., 10 figs., 8 tabs.

  19. Accurate directional borehole drilling: A case study at Navajo Dam, New Mexico

    SciTech Connect

    Kravits, S.J.; Sainato, A.; Finfinger, G.L.

    1987-01-01

    The project was conducted at Navajo Dam in northern New Mexico at the request of the Bureau of Reclamation. The trajectory of the demonstration borehole was designed to intercept a 5-ft-radius target at the final or ''punchout'' distance of 885 ft. The elevation of the borehole at this distance was within the target; the borehole punchout coordinates were 8.81 ft southwest of the target. As a result of the demonstrated accuracy, the Bureau of Reclamation has contracted the accurate drilling of boreholes as long as 600 ft from the inside of a short tunnel, to control water seepage in the right abutment. This resulted in a substantial cost savings compared to the original plan of constructing a longer tunnel and drilling 150-ft boreholes.

  20. Post-treatment of UASB reactor effluent in waste stabilization ponds and in horizontal flow constructed wetlands: a comparative study in pilot scale in Southeast Brazil.

    PubMed

    Bastos, R K X; Calijuri, M L; Bevilacqua, P D; Rios, E N; Dias, E H O; Capelete, B C; Magalhães, T B

    2010-01-01

    The results of a 20-month period study in Brazil were analyzed to compare horizontal-flow constructed wetlands (CW) and waste stabilization pond (WSP) systems in terms of land area requirements and performance to produce effluent qualities for surface water discharge, and for wastewater use in agriculture and/or aquaculture. Nitrogen, E. coli and helminth eggs were more effectively removed in WSP than in CW. It is indicated that CW and WSP require similar land areas to achieve a bacteriological effluent quality suitable for unrestricted irrigation (10(3) E. coli per 100 mL), but CW would require 2.6 times more land area than ponds to achieve quite relaxed ammonia effluent discharge standards (20 mg NH(3) L(-1)), and, by far, more land than WSP to produce an effluent complying with the WHO helminth guideline for agricultural use (< or =1 egg per litre). PMID:20182079

  1. Survey of land subsidence - case study: The land subsidence formation in artificial recharge ponds at South Hamadan Power Plant, northwest of Iran

    NASA Astrophysics Data System (ADS)

    Aghai, Ahmad Khorsandi

    2015-02-01

    The artificial recharge is a technique of aquifer conservation for land subsidence. But in this article, the phenomenon of land subsidence and the resulting cracks and fissures at the study area are formed in recharge ponds. This is a new phenomenon and in this research the geometrical properties of the fissures of recharge ponds are measured. The results reveal the existence of fine layers in the geology of the aquifer, which are displaced in the long run as the consequence of groundwater overdraft. At the site of the artificial recharge subject of this research, the difference between the quality of recharge water and the aquifer and their interaction have intensified the instability and the movement of the fine sediments. In addition, the neglect of hydraulic principles of the groundwater during the construction and operation of the recharge wells has resulted in turbulent and speed flows, intensified displacement of fine sediments and ultimately the localized subsidence at the site of the plan.

  2. The dam breakage of Baia Mare??a pilot study of magnetic screening

    NASA Astrophysics Data System (ADS)

    Wehland, F.; Panaiotu, C.; Appel, E.; Hoffmann, V.; Jordanova, D.; Jordanova, N.; Denut, I.

    Magnetic screening in the area of Baia Mare (Romania) was carried out in June 2000 in order to detect the degree of environmental pollution and to test the applicability of this method in this area. With a long tradition of mining activities, a gradual pollution of soil, air and rivers took place continuously in addition to smaller accidents in this area until the dam breakage on the 30.1.2000. During this accident, about 100,000 m 3 of mud containing cyanide and heavy metals leaked out and moved over fields and through a village into the river system of Lapûs, Someş, Tisza and Danube. Initial magnetic monitoring carried out during the translocation of the polluted waters along the Bulgarian part of the Danube revealed the effectiveness of the method for a proper and fast identification of pollution both in time and space even at remote distances from the source. For the later pilot project magnetic ( χ) screening was performed using a portable Bartington MS2 kappameter with a D-loop sensor. In addition fine-grained material (<0.5 mm) was sampled from the fields and river sediments and measured in the laboratory using a MS2 B-sensor. The results of the collected samples show a clear decrease in χ with increasing distance from the dams and mining areas in a regional and local scale, while the results gained by the MS2-D strongly depend on the nature of the ground. The dynamic geological setting around Baia Mare (fluvial sediments and valley fills), produces a heterogeneous background signal. A continuous monitoring system controlling the basic conditions could overcome these limitations.

  3. Photosynthesis and fish production in culture ponds

    SciTech Connect

    Szyper, J.P.

    1995-12-31

    The widely-cultured Nile tilapia, Oreochromis niloticus, has been the major species used in standardized experiments by the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/ACRSP). Yields of Nile Tilapia from fertilized, unfed ponds have served as a bioassay for effectiveness of pond management protocols developed during worldwide tropical experiments. Yield rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates of primary production. Fish production is related to daytime net photosynthetic production, but it is not clear whether production of food materials or oxygen is the more direct influence. Excessively high standing stocks of phytoplankton are not the best net producers, and increase and risk of nighttime oxygen depletion. Fish readily grow to individual sizes of 200-300 g/fish in fertilized ponds, which is sufficient market size in many locations. Supplemental feeding of caged or free-ranging fish greatly accelerates growth beyond 300 g and potentiates high areal yields; the PD/A CRSP has also developed efficient feeding regimes and shown that supplemental feeding need not begin before fish reach 200 g weight. High standing stocks of phytoplankton and high photosynthetic rates in eutrophic ponds make study of photosynthesis possible without radioisotopes. Such ponds also exhibit complete extinction of incident solar radiation within shallow depths, and vertical temperature structure resembling that of deeper bodies of water. These characteristics make ponds useful as microcosms for study of some aspects of photosynthesis in natural waters.

  4. Determining the Population Size of Pond Phytoplankton.

    ERIC Educational Resources Information Center

    Hummer, Paul J.

    1980-01-01

    Discusses methods for determining the population size of pond phytoplankton, including water sampling techniques, laboratory analysis of samples, and additional studies worthy of investigation in class or as individual projects. (CS)

  5. Effect of soil conditions on solar pond performance

    SciTech Connect

    Leboeuf, C.M.; Johnson, D.H.

    1984-01-01

    A recent effort to design a one-acre solar pond at the US Air Force Academy brought up several research issues pertaining to solar pond performance prediction. This report addresses those issues. Interactions of the pond with the soil below it have historically been estimated using very simplistic techniques that tend to ignore soil composition, moisture content, and the coupled heat and moisture transport phenomena. This study examines the models of soil thermal conductivity and heat and mass transport in soils under imposed temperature gradients to assess the potential applicability of these models to solar pond modeling. In addition, a computer simulation code is developed that incorporates the soil thermal conductivity model. Using the code, a parametric analysis was performed illustrating the impact of this property on pond behavior and the importance of experimental model verification for the range of soil temperatures experienced in solar ponds. Implications of the combined heat and moisture movement theory on solar pond performance are presented.

  6. Using Uav to Detect Shoreline Changes: Case Study - Pohranov Pond, Czech Republic

    NASA Astrophysics Data System (ADS)

    Čermáková, I.; Komárková, J.; Sedlák, P.

    2016-06-01

    The paper describes utilization of an unmanned aerial vehicle (UAV) for detection of changes of shorelines. UAV is used as a cheep and on-demand available possibility how to collect remotely sensed data. Its utilization is limited by legal regulations and weather conditions. Paper deals with utilization of UAV for monitoring small water area and particularly study of changes of shorelines. Study contains other methods of classification. After classification will be data processed for next calculations. Indices regarding shoreline changes are in the study also. In conclusion, study contains obtainment findings and encouragement for the future.

  7. Delineation of subsurface structures using resistivity, VLF and radiometric measurement around a U-tailings pond and its hydrogeological implication

    NASA Astrophysics Data System (ADS)

    Banerjee, K. S.; Sharma, S. P.; Sarangi, A. K.; Sengupta, D.

    The hydrogeological characteristics of the uranium mill tailings pond in the vicinity of Jaduguda (Jharkhand, India) were investigated to examine possible contamination and suggest suitable remedial measures, if required. As the hydrogeological characteristics of subsurface geology are closely related to the electrical properties of the subsurface, geophysical measurements using electrical resistivity coupled with Very Low Frequency electromagnetic method and radiation study were used to investigate the geophysical and geological condition of mill tailings in order to characterize the subsurface structures of the tailings pond. The resistivity interpretation depicted the thickness of the soil cover and thickness of tailings in the pond, as well as the depth to the basement. It also suggested the possible flow direction of leachate. It was observed that the resistivity of the top layer decreases in the direction opposite to the dam axis, which in turn, indicated that the groundwater movement occurs in the opposite direction of the dam axis (in the northwest direction). The VLF method depicted the fractures through which groundwater moves, and also showed the current density alignment in the northwest direction at 10 m depth. The radiation measurement showed relatively higher counts in the northwest direction. This correlated well with the resistivity measurement. The current density at a depth of 20 m showed a closed contour suggesting no groundwater movement in the area at this depth, and that high conductivity material was confined to the tailings area only. It was concluded that groundwater moves in opposite direction of the dam axis at shallower depth only. It was found that continuation of fractures do not extend to deeper depths, which suggested that the tailings storage facility at Jaduguda was reasonably safe from any downward contamination.

  8. Combining mariculture and seawater-based solar ponds

    SciTech Connect

    Lowrey, P.; Ford, R.; Collando, F.; Morgan, J.; Frusti, E. . Dept. of Mechanical Engineering)

    1990-05-01

    Solar ponds have been thoroughly studied as a means to produce electricity or heat, but there may be comparable potential to use solar ponds to produce optimized environments for the cultivation of some aquaculture crops. For this, conventional brine-based solar ponds could be used. This strategy would probably be most suitable at desert sites where concentrated brine was abundant, pond liners might not be needed, and the crop produced could be shipped to market. Generally, a heat exchanger would be required to transfer heat from the solar pond into the culture ponds. Culture ponds could therefore use either fresh or marine water. In contrast, this paper explores seawater-based solar ponds. These are solar ponds which use seawater in the bottom storage zone and fresh water in the upper convective zone. Because the required temperature elevations for mariculture are only about 10{degrees}C, seawater-based solar ponds are conceivable. Seawater-based ponds should be very inexpensive because, by the shore, salt costs would be negligible and a liner might be unnecessary.

  9. Radioecological implications of the Par Pond drawdown

    SciTech Connect

    Hickey, H.; Whicker, F.W.

    1991-12-05

    The drawdown of the Par Pond reservoir created dramatic alterations in this formerly stable lentic ecosystem. In addition, the radiation environment at Par Pond has changed significantly because of the exposure of Cesium 137-contaminated sediments and the appearance of new transport pathways to the terrestrial environment. In response to this situation, SREL was asked to study the radioecological implications of the reservoir drawdown. This report contains the objectives, methods, and results of the SREL study.

  10. Beaver damming, fluvial geomorphology, and climate in Yellowstone National Park, Wyoming

    NASA Astrophysics Data System (ADS)

    Persico, L.; Meyer, G.

    2008-12-01

    Beaver habitation is an important component of many fluvial landscapes that can impact a variety of hydrologic, geomorphic, and ecologic processes. Beaver damming, via long term valley aggradation, is thought to be important to the postglacial geomorphic evolution of many smaller mountain stream networks in the western United States. Loss of beaver dams can also cause rapid channel incision. Although several studies have documented rapid short-term aggradation of channels behind single beaver dams, there is little actual data on the long-term cumulative effect of beaver damming. In Yellowstone''s Northern Range, field surveys and stratigraphic section along six streams in the Northern Range reveal net thickness of mostly <2 m and patchy distribution of Holocene beaver-pond deposits. We estimate that reaches with clear morphologic and stratigraphic evidence for beaver-related aggradation constitute about 19% of the total stream network length. Reaches with probable and possible beaver-related aggradation make up an additional 8% and 2% of the network, respectively. The remaining 71% of the network has no clear evidence for beaver-related aggradation. Thirty-nine radiocarbon ages on beaver-pond deposits in northern Yellowstone fall primarily within the last 4000 yr, but gaps in dated beaver occupation from 2200-1800 and 950-750 cal yr BP correspond with severe and persistent droughts that likely caused low to ephemeral discharges in smaller streams. In the last two decades, severe drought has also caused streams that were occupied by beaver in the 1920s to become ephemeral. Beaver have been largely absent from the Northern Range since the mid-20th century, probably due to multiple ecological and climatic factors. This loss of beaver is thought to have led to widespread degradation of stream and riparian habitat via channel incision. Although 20th-century beaver loss has caused significant channel incision at some former dam sites, downcutting elsewhere in northern

  11. Retinal Thickness Measured by Spectral Domain Optical Coherence Tomography in Eyes without Retinal Abnormalities: the Beaver Dam Eye Study

    PubMed Central

    Myers, Chelsea E.; Klein, Barbara E. K.; Meuer, Stacy M.; Swift, Maria K.; Chandler, Charles S.; Huang, Yijun; Gangaputra, Sapna; Pak, Jeong W.; Danis, Ronald P.; Klein, Ronald

    2014-01-01

    Purpose To examine relationships of age, sex, and systemic and ocular conditions with retinal thickness measured by spectral-domain ocular coherence tomography (SD-OCT) in participants without retinal disease. Design Longitudinal study. Methods Setting Population-based cohort. Study Population Persons aged 43-86 years living in Beaver Dam, Wisconsin in 1988-1990. Observation Procedures Retinal thickness was measured via SD-OCT at the Beaver Dam Eye Study examination in 2008-2010. Retinal disease was determined by ophthalmoscopy, fundus photography, or SD-OCT. Main Outcome Measures Retinal thickness from the inner limiting membrane to Bruch's membrane. Results The retina was thickest in the inner circle (mean 334.5 μm) and thinnest in the center subfield (285.4 μm). Mean retinal thickness decreased with age in the inner circle (P<0.0001) and outer circle (P<0.0001). Adjusting for age, eyes in men had thicker retinas than eyes in women in the center subfield (P<0.001) and inner circle (P<0.001). Sex, axial length/corneal curvature ratio, and peak expiratory flow rate were associated with center subfield thickness. Sex and peak expiratory flow rate were associated with retinal thickness in the inner circle. Alcohol consumption, age, axial length/corneal curvature ratio, cataract surgery, ocular perfusion pressure, and peak expiratory flow rate were associated with retinal thickness in the outer circle. Conclusions This study provides data for retinal thickness measures in eyes of individuals aged 63 years and older without retinal disease. This information may be useful for clinical trials involving the effects of interventions on retinal thickness and for comparisons with specific retinal diseases affecting the macula. PMID:25461295

  12. Studies on light intensity distribution inside an open pond photo-bioreactor.

    PubMed

    Pandey, Ramakant; Sahu, Akhilesh; K K, Vasumathi; M, Premalatha

    2015-08-01

    Light intensity profiles inside an open tank were studied using ANSYS Fluent. Experiments were performed by taking Scenedesmus arcuatus, green microalgae at three different concentrations under actual sunlight conditions. Absorption of light intensity at different depths was measured experimentally. The results generated from CFD simulations were compared with the experimental results and the cornet model. It has been found that there is a good agreement between the light intensity profile obtained from the CFD simulation and that calculated using the Cornet's model. Light intensity profiles at different depths were calculated using CFD simulation by varying the dimensions of the tank. The effect of wall reflectivity, diffuse fraction and scattering phase function on light profile in side open tank are also studied using CFD simulation. PMID:25868715

  13. The effect of river damming on vegetation: is it always unfavourable? A case study from the River Tiber (Italy).

    PubMed

    Ceschin, Simona; Tombolini, Ilaria; Abati, Silverio; Zuccarello, Vincenzo

    2015-05-01

    River damming leads to strong hydromorphological alterations of the watercourse, consequently affecting river vegetation pattern. A multitemporal and spatial analysis of the dam effect on composition, structure and dynamic of the upstream vegetation was performed on Tiber River at Nazzano-dam (Rome). The main research questions were as follows: How does plant landscape vary over time and along the river? Where does the dam effect on vegetation end? How does naturalistic importance of the vegetation affected by damming change over time? Data collection was performed mapping the vegetation in aerial photos related to the period before (1944), during (1954) and after dam construction (1984, 2000). The plant landscape has significantly changed over time and along the river, particularly as a result of the dam construction (1953). The major vegetation changes have involved riparian forests and macrophytes. Dam effect on vegetation is evident up to 3 km, and gradually decreases along an attenuation zone for about another 3 km. Despite the fact that the damming has caused strong local hydromorphological modification of the river ecosystem transforming it into a sub-lacustrine habitat, it has also led to the formation of wetlands of considerable naturalistic importance. Indeed, in these man-made wetlands, optimal hydrological conditions have been created by favouring both the expansion of pre-existing riparian communities and the rooting of new aquatic communities, albeit typical of lacustrine ecosystems. Some of these plant communities have become an important food resource, refuge or nesting habitats for aquatic fauna, while others fall into category of Natura 2000 habitats. Therefore, river damming seems to have indirectly had a "favourable" effect for habitat conservation and local biodiversity. PMID:25920677

  14. Topics on distance correlation, feature screening and lifetime expectancy with application to Beaver Dam eye study data

    NASA Astrophysics Data System (ADS)

    Kong, Jing

    This thesis includes 4 pieces of work. In Chapter 1, we present the work with a method for examining mortality as it is seen to run in families, and lifestyle factors that are also seen to run in families, in a subpopulation of the Beaver Dam Eye Study that has died by 2011. We find significant distance correlations between death ages, lifestyle factors, and family relationships. Considering only sib pairs compared to unrelated persons, distance correlation between siblings and mortality is, not surprisingly, stronger than that between more distantly related family members and mortality. Chapter 2 introduces a feature screening procedure with the use of distance correlation and covariance. We demonstrate a property for distance covariance, which is incorporated in a novel feature screening procedure based on distance correlation as a stopping criterion. The approach is further implemented to two real examples, namely the famous small round blue cell tumors data and the Cancer Genome Atlas ovarian cancer data Chapter 3 pays attention to the right censored human longevity data and the estimation of lifetime expectancy. We propose a general framework of backward multiple imputation for estimating the conditional lifetime expectancy function and the variance of the estimator in the right censoring setting and prove the properties of the estimator. In addition, we apply the method to the Beaver Dam eye study data to study human longevity, where the expected human lifetime are modeled with smoothing spline ANOVA based on the covariates including baseline age, gender, lifestyle factors and disease variables. Chapter 4 compares two imputation methods for right censored data, namely the famous Buckley-James estimator and the backward imputation method proposed in Chapter 3 and shows that backward imputation method is less biased and more robust with heterogeneity.

  15. Focusing on dam safety

    SciTech Connect

    Lagassa, G.

    1993-01-01

    With increased relicensing activity and a federal emphasis on safety, dam repair and refurbishment is a growing business. Providers of goods and services are gearing up to meet the dam repair and rehabilitation needs that result.

  16. Small-dam rehabs

    SciTech Connect

    Denning, J.

    1993-01-01

    This article examines the economics of maintenance, rehabilitation and improvement for small, aging, high-hazard dams. The topics of the article include raising the height of the spillway and repairing deteriorated concrete in the spillway of Fellows Lake Dam, emergency repair of the outlet conduit and replacement of riprap on the upstream slope of Storrie Lake Dam, and extensive rehabilitation of Reeves Lake Dam.

  17. Dam Mycobacterium avium subspecies paratuberculosis (MAP) infection status does not predetermine calves for future shedding when raised in a contaminated environment: a cohort study.

    PubMed

    Eisenberg, Susanne W F; Rutten, Victor P M G; Koets, Ad P

    2015-01-01

    Uptake of Mycobacterium avium subsp. paratuberculosis (MAP) by calves in the first days of life from colostrum, milk and faeces is regarded an important moment of transmission. The objective of this study was to quantify the association between the MAP status of dams as determined by the presence of MAP DNA and antibody in colostrum and that of DNA in faeces and the environment with subsequent MAP shedding of their daughters. A cohort of 117 dam-daughter pairs giving birth/being born on eight commercial dairy farms with endemic paratuberculosis was followed where colostrum, faecal and environmental samples (dust) were analysed for the presence of MAP using an IS900 real-time PCR. Antibodies in colostrum were measured by ELISA. Analysis of dust samples showed that on all farms environmental MAP exposure occurred continuously. In significantly more colostrum samples (48%) MAP DNA was detected compared to faecal samples (37%). MAP specific antibodies were present in 34% of the colostrum samples. In total MAP DNA was present in faecal samples of 41% of the daughters at least once during the sampling period. The association between faecal shedding in the offspring and the dam MAP status defined by MAP PCR on colostrum, MAP PCR on faeces or ELISA on colostrum was determined by an exact cox regression analysis for discrete data. The model indicated that the hazard for faecal shedding in daughters born to MAP positive dams was not significantly different compared to daughters born to MAP negative dams. When born to a dam with DNA positive faeces the HR was 1.05 (CI 0.6; 1.8) and with DNA positive colostrum the HR was 1.17 (CI 0.6; 2.3). When dam status was defined by a combination of both PCR outcomes (faeces and colostrum) and the ELISA outcome the HR was 1.26 (CI 0.9; 1.9). Therefore, this study indicates that neither the presence of MAP DNA in colostrum, MAP DNA in faeces nor the presence of MAP antibodies in colostrum of the dam significantly influences the hazard of

  18. Hoover Dam Learning Packet.

    ERIC Educational Resources Information Center

    Bureau of Reclamation (Dept. of Interior), Washington, DC.

    This learning packet provides background information about Hoover Dam (Nevada) and the surrounding area. Since the dam was built at the height of the Depression in 1931, people came from all over the country to work on it. Because of Hoover Dam, the Colorado River was controlled for the first time in history and farmers in Nevada, California, and…

  19. Combined electron microscopy and vibrational spectroscopy study of corroded Magnox sludge from a legacy spent nuclear fuel storage pond

    NASA Astrophysics Data System (ADS)

    Gregson, Colin R.; Goddard, David T.; Sarsfield, Mark J.; Taylor, Robin J.

    2011-05-01

    Samples of filtered particulates and sludges, formed from corroding magnesium alloy clad uranium metal ("Magnox") fuel elements, collected from one of the legacy nuclear fuel storage ponds located at Sellafield (UK) were investigated by Environmental Scanning Electron Microscopy with Energy Dispersive X-Ray analysis (ESEM/EDX), micro-Raman spectroscopy and Fourier transform infra-red spectroscopy (FT-IR). ESEM imaging confirmed the dominant morphology to be clusters of interlocking platelets typical of brucite (Mg(OH) 2). EDX analysis was suggestive of some conversion to the related phase, hydrotalcite (Mg 6Al 2(CO 3)(OH) 16·4H 2O), due to elevated levels of Al associated with Mg. Other apparent morphologies were less commonly observed including flaky sheets, consistent with earlier stages of Magnox alloy corrosion. In a few specific cases, rods were also observed suggestive of some conversion to Mg-hydroxycarbonate phases. Discrete phases rich in U were also identified. Fluorescence in the Raman spectroscopy also indicated surface coatings of organic macromolecules and iron sulphide on hematite containing particles, attributed to microbial activity within the open air pond. Some specific differences in the solid phases between pond areas with differing conditions were apparent.

  20. Olive mill wastewater evaporation management using PCA method Case study of natural degradation in stabilization ponds (Sfax, Tunisia).

    PubMed

    Jarboui, Raja; Sellami, Fatma; Azri, Chafai; Gharsallah, Néji; Ammar, Emna

    2010-04-15

    Olive mill wastewater (OMW) evaporation ponds management was investigated in five serial evaporation open-air multiponds of 50 ha located in Sfax (Tunisia). Physico-chemical parameters and microbial flora evolution were considered. Empirical models describing the OMW characteristic changes with the operation time were established and Principal Component Analysis (PCA) described the correlation between physico-chemical and biological parameters. COD, BOD, total solids, polyphenols and electrical conductivity exhibited first-order models. Four groups exhibited high correlations. The first included temperature, density, COD, TSS, TS, BOD, VS, TOC, TKN, polyphenols and minerals. The second group was made up of yeasts and moulds. The third group was established with phenolic compounds, total sugars, fats, total phosphorous, NH(4)(+) and pH. The fourth group was constituted by exclusively aerobic bacteria. Bacterial-growth toxic effect was exhibited by high organic load, ash content and polyphenols, whereas moulds and yeasts were more adapted to OMW. During the storage, all the third group parameter values decreased and were inversely related to the others. In the last pond, COD, BOD, TS and TSS rates were reduced by 40%, 50%, 50% and 75% respectively. The evaporation and the biological activity were the main processes acting, predicting the OMW behavior during evaporation in air-open ponds. PMID:20036054

  1. Radiological impact of Par Pond drawdown from liquid effluent pathways

    SciTech Connect

    Carlton, W.H.; Hamby, D.M.

    1991-10-25

    The water level of Par Pond has been lowered over the past several months to reduce the effects in the event of catastrophic dam failure while assessing the condition of the dam and determining if repairs are necessary. In lowering the level of Par Pond, 60 billion liters of water containing low levels of tritium and cesium-137 were discharged to several onsite streams. SRS surface streams flow to the Savannah River. An assessment made to determine the total amount of tritium and Cs-137 discharged and to estimate the consequences to downstream Savannah River users. It is estimated that a total of 160 curies of tritium were displaced from Par Pond to the Savannah River between June 28, 1991 and September 19, 1991. This release could hypothetically result in a maximum individual dose of 3. 2{times}10{sup {minus}4} mrem and a total (80-km and drinking water populations) population dose of 1.4{times}10{sup {minus}2} person-rem. Likewise, a maximum individual dose of 5.0{times}10{sup {minus}2} mrem and a total population dose of 1.7{times}10{sup {minus}1} person- rem are predicted as a result of an estimated 0.21 curies of Cs-137 being discharged from Par Pond to the Savannah River.

  2. Study of Active Faults in the Three Gorges Dam region by Detecting and Relocating Aftershocks

    NASA Astrophysics Data System (ADS)

    Huang, R.; Zhu, L.; Xu, Y.

    2014-12-01

    Seismicity in the Three Gorges Dam (TGD) region and its adjacent areas increased dramatically as the water- level of the TGD reservoir rises since its completion in 2003. Accordingly, many efforts have been put forward to quantify the seismicity and geological hazards in the region. However, the precise detective of earthquakes, especially for the minor ones, remains difficulty because of sparse distribution of permanent seismic stations. From December 2013 to June 2014, we deployed 30 three-component broadband seismic stations in the TGD region. During the deployment, we recorded two earthquakes of magnitudes lager than 5.0, one occurred on December 16th 2013 in Badong and another on March 30th 2014 in Zigui. We firstly used a sliding-window cross-correlation (SCC) detection technique to supplement the events catalog from the China Earthquake Networks Center. Over 500 new events with ML lager than 0.5 were detected. We then relocated 502 events out of the total 987 events using the double-difference (DD) relocation algorithm. We also determined moment tensors of some large earthquakes using gCAP. The results clearly show two active faults along Yangtze River with dips of 50 degrees and 90 degrees to a maximum depth of 10 km, respectively. And they also reveal that water might have permeated to a depth of 6 km corresponds to the interface of sediments and metamorphic basement beneath Zigui Basin. We thus preliminarily judge that the quakes are triggered by local stress adjustment resulting of fluctuation of Three Gorges reservoir's loading.

  3. Wintertime Emissions from Produced Water Ponds

    NASA Astrophysics Data System (ADS)

    Evans, J.; Lyman, S.; Mansfield, M. L.

    2013-12-01

    Every year oil and gas drilling in the U.S. generates billions of barrels of produced water (water brought to the surface during oil or gas production). Efficiently disposing of produced water presents a constant financial challenge for producers. The most noticeable disposal method in eastern Utah's Uintah Basin is the use of evaporation ponds. There are 427 acres of produced water ponds in the Uintah Basin, and these were used to evaporate more than 5 million barrels of produced water in 2012, 6% of all produced water in the Basin. Ozone concentrations exceeding EPA standards have been observed in the Uintah Basin during winter inversion conditions, with daily maximum 8 hour average concentrations at some research sites exceeding 150 parts per billion. Produced water contains ozone-forming volatile organic compounds (VOC) which escape into the atmosphere as the water is evaporated, potentially contributing to air quality problems. No peer-reviewed study of VOC emissions from produced water ponds has been reported, and filling this gap is essential for the development of accurate emissions inventories for the Uintah Basin and other air sheds with oil and gas production. Methane, carbon dioxide, and VOC emissions were measured at three separate pond facilities in the Uintah Basin in February and March of 2013 using a dynamic flux chamber. Pond emissions vary with meteorological conditions, so measurements of VOC emissions were collected during winter to obtain data relevant to periods of high ozone production. Much of the pond area at evaporation facilities was frozen during the study period, but areas that actively received water from trucks remained unfrozen. These areas accounted for 99.2% of total emissions but only 9.5% of the total pond area on average. Ice and snow on frozen ponds served as a cap, prohibiting VOC from being emitted into the atmosphere. Emissions of benzene, toluene, and other aromatic VOCs averaged over 150 mg m-2 h-1 from unfrozen pond

  4. Water quality and restoration in a coastal subdivision stormwater pond.

    PubMed

    Serrano, Lorimar; DeLorenzo, Marie E

    2008-07-01

    Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to a number of water quality problems including high nutrient, chemical contaminant, and bacterial levels. This study examined the interaction between land use and coastal pond water quality in a South Carolina residential subdivision pond. Eutrophic levels of chlorophyll and phosphorus were present in all seasons. Harmful cyanobacterial blooms were prevalent during the summer months. Microcystin toxin and fecal coliform bacteria levels were measured that exceeded health and safety standards. Low concentrations of herbicides (atrazine and 2,4-D) were also detected during summer months. Drainage from the stormwater pond may transport contaminants into the adjacent tidal creek and estuary. A survey of residents within the pond's watershed indicated poor pet waste management and frequent use of fertilizers and pesticides as possible contamination sources. Educational and outreach activities were provided to community members to create an awareness of the water quality conditions in the pond. Pond management strategies were then recommended, and selected mitigation actions were implemented. Water quality problems identified in this study have been observed in other coastal stormwater ponds of varying size and salinity, leading this project to serve as a potential model for coastal stormwater pond management. PMID:17368919

  5. Phytoplankton as bioindicator for waste stabilization ponds.

    PubMed

    Amengual-Morro, Caterina; Moyà Niell, Gabriel; Martínez-Taberner, Antoni

    2012-03-01

    Waste stabilization ponds are an appropriate technology for domestic onsite wastewater treatment. It is a low-cost technology, requires low maintenance, is highly efficient, mostly natural and remarkably sustainable. In facultative ponds, the existence of an algal population is very important for the stability of the symbiotic relation with aerobic bacteria. The aim of this work is to determine the pattern of microalgae in the facultative and maturation ponds to obtain information for the operation and maintenance work. The important parameters for phytoplankton measured in this study are the organic load, temperature, light penetration, dissolved oxygen and nutrients. Methodology consists in: analysis of main water quality parameters, plankton taxonomic determination and abundance calculation related with the maintenance operations. Results show that cyanobacteria are present in under-loaded conditions and chlorophyceae are present when the pond is overloaded. Using this methodology over time we can obtain a year round pattern to use the phytoplankton as a bioindicator of the pond's conditions. Our conclusion is that the phytoplankton determination and density can be used to know the pond's performance and help the operation and maintenance tasks. PMID:21820796

  6. Elwha River Riparian Vegetation Response to Dams and Dam Removal

    NASA Astrophysics Data System (ADS)

    Shafroth, P. B.; Brown, R. L.; Clausen, A. J.; Chenoweth, J.

    2012-12-01

    Riparian vegetation is highly diverse and influences habitat of aquatic and terrestrial wildlife. Riparian vegetation dynamics are driven by stream flow regime, and fluxes of sediment and large woody debris, all of which can be altered by river damming. Dam removal is often implemented, in part, to help restore degraded riparian vegetation by reversing the alteration of these key drivers. However, increased disturbance and sediment flux associated with transport and exposure of trapped reservoir sediment can complicate a simple return to pre-dam conditions and can favor exotic species. We are studying the effects of dams and their removal on riparian vegetation along the Elwha River in Washington State, where removal of two large dams began in September 2011. To characterize vegetation composition, structure, and diversity prior to dam removal, we sampled 60-150 vegetation plots in 2004, 2005, and 2010 along five cross-valley transects in each of three river reaches: above both dams (upper reach), between the dams (middle reach), and downstream of both dams (lower reach). In summer 2012, we resampled a subset of our plots in the lower and middle reaches to evaluate vegetation and geomorphic change. We also sampled vegetation, topography, and grain size along newly-established transects within the exposed former reservoir behind Elwha Dam, which was removed in 2011 and 2012. Plant community distribution on bottomland geomorphic surfaces along the Elwha is typical of other systems in the region. We identified 8 overstory and 26 understory communities using multivariate analyses. Young bar surfaces (5-20 yrs) were dominated by willow, red alder, and black cottonwood. Floodplains and transitional fluvial terraces (<90yrs) were generally dominated by alder and cottonwood. Mature terraces (>90yrs) were often dominated by big-leaf maple. Douglas fir occurred on both young and old floodplains and terraces. Overstory species composition was more stable from 2005 to 2010

  7. Treatment of piggery wastes in waste stabilization ponds.

    PubMed

    Estrada, V E E; Hernández, D E A

    2002-01-01

    The piggery industry produces high effluent loads. This is due to the high concentration of animals kept in a confined space, foods with high protein content that are not well assimilated by the animals, and poor on-farm water management. In this study, we present the characteristics, design, site selection, soil study, and the construction of a pilot pond system for a family farm located in a warm climate area. The design includes a solids sedimentation phase, an anaerobic pond, a facultative pond and three maturation ponds. Once the system had reached steady state, the organic and bacterial kinetic constants were determined for each pond. The control parameters were determined and the dissolved oxygen and removal efficiency profiles were obtained. The results indicate that the effluent from the second maturation pond complies with the Official Mexican Standard for reuse in agriculture ("1000 FC/100 ml). PMID:11841058

  8. Saltless solar pond

    NASA Technical Reports Server (NTRS)

    Lin, E. I. H. (Inventor)

    1984-01-01

    A solar pond adapted for efficiently trapping and storing radiant solar energy without the use of a salt concentration gradient in the pond is disclosed. A body of water which may be fresh, saline, relatively clear or turbid, is substantially covered by a plurality of floating honeycomb panels. The honeycomb panels are made of a material such as glass which is pervious to short wave solar radiation but impervious to infrared radiation. Each honeycomb panel includes a multitude of honeycomb cells. The honeycomb panels are divided into the elongated honeycomb cells by a multitude of intermediate plates disposed between a bottom plate and top plate of the panel. The solar pond is well suited for providing hot water of approximately 85 to 90 C temperature for direct heating applications, and for electrical power generation.

  9. Effect of thiram and of a hydrocarbon mixture on freshwater macroinvertebrate communities in outdoor stream and pond mesocosms: I. Study design, chemicals fate and structural responses.

    PubMed

    Bayona, Yannick; Roucaute, Marc; Cailleaud, Kevin; Lagadic, Laurent; Bassères, Anne; Caquet, Thierry

    2015-11-01

    Higher-tier ecological risk assessment (ERA) in mesocosms is commonly performed in lotic or lentic experimental systems. These systems differ in their physico-chemical and hydrological properties, leading to differences in chemical fate, community characteristics and potential recovery. This raises the issue of the relevance and sensitivity of community-level endpoints in different types of mesocosms. In this study, macroinvertebrate abundance and biomass estimates were used to assess the effects of a dithiocarbamate fungicide, thiram (35 and 170 µg l(-1)), and a petroleum middle distillate (PMD; 0.01, 0.4, 2 and 20 mg l(-1)) in outdoor stream and pond mesocosms. Streams were continuously treated during 3 weeks followed by a 2-month long post-treatment period. Ponds were treated weekly for 4 weeks, followed by a 10-month long post-treatment period. Taxonomic structure of macroinvertebrate communities was characterized using the α, β and γ components of taxa richness, Shannon and Gini-Simpson indices. Computations were based either on abundance or biomass data. Results clearly highlighted that the effects of chemicals depended on the exposure regime (for thiram) and type of system (for the PMD). Causes of the differences between streams and ponds in the magnitude and nature of effects include differential sensitivity of taxa dwelling in lentic and lotic systems and the influence of hydrology (e.g., drift from upstream) and mesocosm connectivity on recovery dynamics. This study also showed complementarities in the use of both types of mesocosms to improve the characterization of chemical effects on communities in ERA. PMID:26385344

  10. Falmouth pond watchers: Water quality monitoring of Falmouth's coastal ponds. Report from the 1992 season

    SciTech Connect

    Howes, B.L.; Goehringer, D.D.

    1993-04-01

    1992 has seen a significant expansion in the focus of the Pond Watchers program. The long-term, high quality data base for the ponds is now enabling more emphasis on the ecological management and remediation aspects of the study, the ultimate goal of the program. Overall, 1992 saw only slight variation in the water quality conditions of Oyster, Little, Green, Great and Bournes Ponds from previous years, with a declining trend for Green Pond and small improvements in lower Great and Bournes Ponds. However, Oyster Pond showed a potentially significant improvement in bottom water oxygen conditions which suggests a new management direction for this system. All of the ponds continue to exhibit high nutrient levels and periodic bottom water oxygen depletion, especially in their upper reaches, and all stations exceed the nutrient levels specified by the Nutrient Overlay Bylaw. In contrast, the first year measurements in West Falmouth Harbor indicate high levels of water quality, although the inner reaches of the harbor do exceed those levels specified by the Bylaw.

  11. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    NASA Astrophysics Data System (ADS)

    Li, Jianzhu; Sun, Huafeng; Feng, Ping

    2016-05-01

    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  12. Longitudinal sediment-connectivity in a dammed river system using fine sediment analyses - a case study in the Kaja river, Lower Austria

    NASA Astrophysics Data System (ADS)

    Bertsch, R.; Poeppl, R. E.; Glade, T.

    2012-04-01

    In the recent past the concept of connectivity gained increased significance for the understanding of the linkage between different subsystems within river channels and catchments. Based on fine sediment (<2mm) analyses the main objective of the presented work is to analyse the impact of a dam on the longitudinal sediment connectivity in a river channel. The study sites are located alongside the "Kaja" river (lower Austria), which has a catchment area of about 21.3km2. The river is characterised by a series of dams whereof the present work deals with the so called "Sagteich". Measurements of suspended load as well as fine sediment samples from pool-sections were collected up- and downstream of the dam. The suspended load concentrations where analysed by weighting the water and sediment amount. The grain size distribution of the sediment samples from the pool-sections were measured with sieving as well as pipette analyses. The results of the suspended load analysis reveal that the dam is a strong disconnecting factor in longitudinal direction. This disconnectivity cannot be confirmed for fine sediments, which have been determined from the sediment samples collected in the pool-sections. It is argued, that the lateral input of sediments alters the grain size distribution in pool-sections and consequently, any interpretation of longitudinal sediment connectivity, or disconnectivity has to be regarded with reservation in this fraction.

  13. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    NASA Astrophysics Data System (ADS)

    Li, Jianzhu; Sun, Huafeng; Feng, Ping

    2016-06-01

    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  14. Evaluation of solar pond performance

    SciTech Connect

    Wittenberg, L.J.

    1980-01-01

    The City of Miamisburg, Ohio, constructed during 1978 a large, salt-gradient solar pond as part of its community park development project. The thermal energy stored in the pond is being used to heat an outdoor swimming pool in the summer and an adjacent recreational building during part of the winter. This solar pond, which occupies an area of 2020 m/sup 2/ (22,000 sq. ft.), was designed from experience obtained at smaller research ponds located at Ohio State University, the University of New Mexico and similar ponds operated in Israel. During the summer of 1979, the initial heat (40,000 kWh, 136 million Btu) was withdrawn from the solar pond to heat the outdoor swimming pool. All of the data collection systems were installed and functioned as designed so that operational data were obtained. The observed performance of the pond was compared with several of the predicted models for this type of pond. (MHR)

  15. Influence of Beaver Dams on Channel Complexity, Hydrology, and Temperature Regime in a Mountainous Stream

    NASA Astrophysics Data System (ADS)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2013-12-01

    Beaver dams and beaver activity affect hydrologic processes, sediment transport, channel complexity and water quality of streams. Beaver ponds, which form behind beaver dams, increase in-channel water storage affecting the timing and volume of flow and resulting in the attenuation and flattening of the hydrograph. Channel complexity also increases the potential for transient storage (both surface and subsurface) and influences stream temperature. Impacts of beaver dams and beaver activity on stream responses are difficult to quantify because responses are dynamic and spatially variable. Few studies have focused on the reach scale temporal influences on stream responses and further research is needed particularly in quantifying the influence of beaver dams and their role in shaping the stream habitat. This study explores the changing hydrology and temperature regime of Curtis Creek, a mountainous stream located in Northern Utah, in a 560 m long reach where groundwater exchanges and temperature differences were observed over a three-year period. We have collected continuous stream discharge, stream temperature data and performed tracer experiments. During the first year, we were able to capture the pre-beaver activity. In the second year, we captured the impacts of some beaver activity with only a few dams built in the reach, while the third year included the effects of an entire active beaver colony. By the end of the study period, a single thread channel had been transformed into a channel with side channels and backwaters at multiple locations therefore increasing channel complexity. The cumulative influence of beaver dams on reach scale discharge resulted in a slightly losing reach that developed into a gaining reach. At the smaller sub-reach scale, both losing to gaining and gaining to losing transformations were observed. Temperature differences showed a warming effect of beaver dams at the reach scale. The reach stream temperature difference increased on

  16. Truscott Brine Lake solar-pond system conceptual design

    SciTech Connect

    Leboeuf, C.M.; May, E.K.

    1982-08-01

    Discussed is a conceptual design study for a system of electricity-producing salt-gradient solar ponds that will provide power to a chloride control project under construction near Truscott, Tex. The chloride control project comprises a 1200-ha (3000-acre) brine impoundment lake to which brine will be pumped from several salty sources in the Wichita River basin. The solar ponds are formed by natural evaporation of the briny water pumped to Truscott. Heat is extracted from the solar ponds and used to drive organic Rankine-cycle (ORC) generators. Ponds were sized to provide the pumping needs of the chloride control project and the maintenance requirements of the solar ponds. The system includes six solar pond modules for a total area of 63.1 ha, and produces 1290 kW of base load electricity. Although sized for continuous power production, alternative operating scenarios involving production of peak power for shorter durations were also examined.

  17. Field studies of BrO and IO at salt ponds (Namibia and Botswana) and related smog chamber experiments on environmental salt and soil samples

    NASA Astrophysics Data System (ADS)

    Buxmann, Joelle; Balzer, Natalja; Bleicher, Sergej; Kotte, Karsten; Platt, Ulrich; Zetzsch, Cornelius; Pienaar, Jacobus J.

    2010-05-01

    Previous studies have shown that salt lakes provide a significant source for gaseous reactive halogen compounds. Reactive halogen species (RHS) influence the ozone chemistry. Iodine chemistry is known to initiate particle formation, where the relevant nucleation mechanism is not fully understood. The RHS IO and BrO were investigated by Multi- Axis- Differential- Optical- Absorption- Spectroscopy (MAX-DOAS) of scattered sunlight at two different salt ponds. At a coastal salt evaporation pond for production of sodium chloride in Namibia (Walfish Bay) as well as at a natural salt pond in Botswana (Sua Pan) a tropospheric IO signal was observed. In Namibia the slant column density (SCD) rose up to (4.5±0.7) ×1013 molec/cm2 (elevation angle: 5° ). Assuming a typical layer thickness of 500 m, this would correspond to a concentration of (3.3±0.5) ppt. The mean SCD of IO was (2.2±0.5) ×1013 molec/cm2at Sua Pan for 5° elevation angle. At both measurement sites tropospheric BrO remained below the detection limit of 1.8 × 1013molec/cm2or 1.3ppt, respectively. Many aspects of the underlying mechanisms for the release of reactive halogen compounds, their sources and sinks are not well understood yet. In order to investigate the release of RHS soil and salt samples from both measurement sites are exposed to simulated sunlight in a teflon smog-chamber experiment at Bayreuth. RHS are observed by DOAS with a multireflection system. An ozone analyzer, a gas chromátograph (with flame ionisation detector) and a scanning electrostatical classifier with condensation nuclei counter are employed for monitoring hydrocarbons and aerosol, respectively.

  18. In-situ gamma-ray survey of rare-earth tailings dams--A case study in Baotou and Bayan Obo Districts, China.

    PubMed

    Li, Baochuan; Wang, Nanping; Wan, Jianhua; Xiong, Shengqing; Liu, Hongtao; Li, Shijun; Zhao, Rong

    2016-01-01

    An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of (238)U and (232)Th were 3.0 ± 1.0 mg/kg (range: 1.9-4.6 mg/kg) and 321 ± 31 mg/kg (range: 294-355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of (238)U and (232)Th were 5.7 ± 0.5 mg/kg (range: 5.3-6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5-276.3 mg/kg), respectively. The average (232)Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The (232)Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the (232)Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of (232)Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required. PMID:26555365

  19. 16. Parker Dam, only top fourth of dam visible, at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Parker Dam, only top fourth of dam visible, at 320' high, Parker Dam is one of the highest in the world. Much of this height is because dam penetrates well below river bottom to fasten to bedrock. - Parker Dam, Spanning Colorado River between AZ & CA, Parker, La Paz County, AZ

  20. Using seasonal forecasts in a drought forecasting system for water management: case-study of the Arzal dam in Brittany

    NASA Astrophysics Data System (ADS)

    Crochemore, Louise; Ramos, Maria-Helena; Perrin, Charles; Penasso, Aldo

    2014-05-01

    The Arzal dam is located at the outlet of the Vilaine River basin (10,000 km2) in Brittany, France. It controls a reservoir (50 hm3) managed for multiple water uses: drinking water, flood control, irrigation, sailing and fish by-passing. Its location in the estuary creates a physical divide between upstream freshwater and downstream saline water. The reservoir thus plays an essential role in the regional water management system. Its operational management during the summer season poses several challenges, mainly related to the quantification of future water inflows and the risks of having restricted water availability for its different uses. Indeed, the occurrence of severe drought periods between May and October may increase the risk of salt intrusion and drinking water contamination due to lock operations. Therefore it is important to provide decision-makers with reliable low-flow forecasts and risk-based visualization tools, which will support their choice of the best strategy for allocation of water among different users and stakeholders. This study focuses on an integrated hydro-meteorological forecasting system developed to forecast low flows upstream the Arzal dam and based on a lumped hydrological model. Medium-range meteorological forecasts from the ECMWF ensemble prediction system (51 scenarios up to 9 days ahead) are combined with seasonal meteorological forecasts also from ECMWF to provide extended streamflow forecasts for the summer period. The performance of the forecasts obtained by this method is compared with the performance of two benchmarks: (i) flow forecasts obtained using an ensemble of past observed precipitation series as precipitation scenarios, i.e. without any use of forecasts from meteorological models and (ii) flow forecasts obtained using the seasonal forecasts only, i.e. without medium-term information. First, the performance of ensemble forecasts is evaluated and compared by means of probabilistic scores. Then, a risk

  1. Fragility Analysis of Concrete Gravity Dams

    NASA Astrophysics Data System (ADS)

    Tekie, Paulos B.; Ellingwood, Bruce R.

    2002-09-01

    Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

  2. The Little School Pond

    ERIC Educational Resources Information Center

    Rawitscher-Kunkel, Erika

    1973-01-01

    A small pond in a schoolyard provided year-round biological activities for children. As seasons changed, concepts and life relations also changed. Besides microscopic organisms in water, children learned about microscopic algae, detritus, and food chains. Concepts of predator-prey relationships and of ecosystems were successfully developed. (PS)

  3. Let's Build a Pond!

    ERIC Educational Resources Information Center

    Winkeljohn, Dorothy R.; Earl, Robert D.

    1982-01-01

    Describes a game for grades three-six designed to demonstrate the interdependence between living things and the physical factors of their environment. Although instructions (including preparing game cards) are provided related to a pond, the game adapts to other environments such as a field, woodland, or desert. (Author/JN)

  4. Partitioned pond aquaculture systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    World aquaculture is dominated by the use of simple earthen ponds in which suitable water quality is maintained by photosynthetic processes. Relying upon sunlight to maintain water quality offers the lowest cost and most sustainable approach to fish or shellfish production, which explains the popula...

  5. Quality control summary report for the RFI/RI assessment of the submerged sediment core samples taken at Par Pond, Pond C, and L-Lake

    SciTech Connect

    Koch, J. II

    1996-12-01

    This report presents a summary of the sediment characterization performed under the direction of the Westinghouse Savannah River Company`s (WSRC) Environmental Protection Department/Environmental Monitoring Section (EPD/EMS) in support of Par Pond, Pond C, and L- Lake. This characterization will be a screening study and will enable the Environmental Sciences Section (ESS) to develop a defensible contaminants of concern list for more extensive characterization of the Par Pond, Pond C, and L-Lake.

  6. About the interest of a zooplankton compartment in pond systems: methodology to study the growth kinetic of Daphnia pulex on Scenedesmus sp.

    PubMed

    Liady, M N D; Tangou, T T; Fiogbe, E D; Cauchie, H-M; Vasel, J-L

    2015-01-01

    A reliable characterization of cladocerans' growth kinetic on their substrates is crucial for the estimation of their biochemical conversion rate in pond models. Although many studies reported cladocerans' growth inhibitions by high chlorophyceae contents, their growth kinetics had continued to be described in many pond system models by Monod-type kinetic, which describes growth saturation by high substrate contents, but fails to explain the disappearance of cladocerans observed during chlorophyceae's bloom periods. This study aimed to develop a methodology and assess whether growth-inhibition-type models used to describe microbial growth kinetics can be applicable to cladocerans. Experiments were carried out using Daphnia pulex populations and Scenedesmus sp. First, biomass of D. pulex was measured through digital image processing (DIP) during growth experiments. Then, three candidate models (i.e., Andrews, Edward and Haldane models), along with the Monod model, were fitted to the observed data and compared. The results showed that the DIP technique provided reliable results for estimating the biomass of D. pulex. Our findings show that the candidate growth inhibition-type models satisfactorily described D. pulex's growth kinetic (86% variance accounted for). Scenesdemus sp. were not strong inhibitors of the growth of D. pulex (high inhibition constant and low half-saturation constant found). PMID:26442483

  7. Dams and transnational advocacy: Political opportunities in transnational collective action

    NASA Astrophysics Data System (ADS)

    Fu, Teng

    Possible arguments to explain the gradual decline in big dam development and its site transferring from developed to developing countries include technical, economic, and political factors. This study focuses on the political argument---the rise of transnational anti-dam advocacy and its impact on state policy-making. Under what conditions does transnational anti-dam advocacy matter? Under what conditions does transnational advocacy change state dam policies (delay, scale down, or cancel)? It examines the role of transnational anti-dam actors in big dam building in a comparative context in Asia. Applying the social movement theory of political opportunity structure (POS) and using the qualitative case-study method, the study provides both within-case and cross-case analyses. Within-case analysis is utilized to explain the changing dynamics of big dam building in China (Three Gorges Dam and proposed Nu/Salween River dam projects), and to a lesser extent, Sardar Sarovar Project in India and Nam Theun 2 Dam in Laos. Different domestic and international POS (DPOS and IPOS) impact the strategies and outcomes of anti-dam advocacies in these countries. The degree of openness of the POS directly affects the capacity of transnational efforts in influencing state dam policies. The degree of openness or closure is measured by specific laws, institutions, discourse, or elite allies (or the absence of these) for the participation of non-state actors on big dam issues at a particular moment. This degree of openness is relative, varying over time, across countries and regions. This study finds that the impact of transnational anti-dam activism is most effective when both DPOS and IPOS are relatively open. Transnational anti-dam advocacy is least effective in influencing state dam policies when both DPOS and IPOS are relatively closed. Under a relatively open DPOS and closed IPOS, transnational anti-dam advocacy is more likely to successfully change state dam policies and even

  8. 31. AVALON DAM OUTLET WORKS FROM CREST OF DAM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. AVALON DAM - OUTLET WORKS FROM CREST OF DAM INCLUDING SPILLWAY NO. 1 AND CYLINDER GATE DISCHARGE PORTALS. VIEW TO SOUTHEAST - Carlsbad Irrigation District, Avalon Dam, On Pecos River, 4 miles North of Carlsbad, Carlsbad, Eddy County, NM

  9. 9. Excavation work at Pleasant Dam (now called Waddell Dam). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Excavation work at Pleasant Dam (now called Waddell Dam). Photographer unknown, July, 22, 1926. Source: Maricopa County Municipal Water Conservation District Number One (MWD). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  10. The application of remote sensing in the environmental risk monitoring of tailings pond: a case study in Zhangjiakou area of China

    NASA Astrophysics Data System (ADS)

    Xiao, Rulin; Shen, Wenming; Fu, Zhuo; Shi, Yuanli; Xiong, Wencheng; Cao, Fei

    2012-10-01

    As a kind of huge environmental risk source, tailings pond could cause a huge environmental disaster to the downstream area once an accident happened on it. Therefore it has become one key target of the environmental regulation in china. Especially, recently environmental emergencies caused by tailings pond are growing rapidly in China, the environmental emergency management of the tailings pond has been confronting with a severe situation. However, the regulatory agency is badly weak in the environmental regulation of tailings pond, due to the using of ground surveys and statistics which is costly, laborious and time consuming, and the lacking of strong technical and information support. Therefore, in this paper, according to the actual needs of the environmental emergency management of tailings pond, we firstly make a brief analysis of the characteristics of the tailings pond and the advantages and capability of remote sensing technology, and then proposed a comprehensive and systematic indexes system and the method of environmental risk monitoring of tailings pond based on remote sensing and GIS. The indexes system not only considers factors from the upstream area, the pond area and the downstream area in a perspective of the risk space theory, but also considers factors from risk source, risk receptor and risk control mechanism in a perspective of risk systems theory. Given that Zhangjiakou city has up to 580 tailings pond and is nearly located upstream of the water source of Beijing, so finally we apply the proposed indexes system and method in Zhangjiakou area in China to help collect environmental risk data of tailings pond in that area and find out it works well. Through the use case in Zhajiakou, the technique of using remote sensing to monitor environmental risk of tailings pond is feasible and effective, and would contribute to the establishment of `Space-Ground' monitoring network of tailings pond in future.