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Sample records for lookout point dam

  1. Optimization of Hydroacoustic Equipment Deployments at Lookout Point and Cougar Dams, Willamette Valley Project, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Khan, Fenton; Ploskey, Gene R.; Hughes, James S.; Fischer, Eric S.

    2010-08-18

    The goal of the study was to optimize performance of the fixed-location hydroacoustic systems at Lookout Point Dam (LOP) and the acoustic imaging system at Cougar Dam (CGR) by determining deployment and data acquisition methods that minimized structural, electrical, and acoustic interference. The general approach was a multi-step process from mount design to final system configuration. The optimization effort resulted in successful deployments of hydroacoustic equipment at LOP and CGR.

  2. Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Lookout Point Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Hughes, James S.; Fischer, Eric S.; Trott, Donna M.; Ploskey, Gene R.

    2011-07-01

    This report presents the results of an evaluation of juvenile salmonid passage and distribution at Lookout Point Dam (LOP) on the Middle Fork Willamette River. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District (USACE). The goal of the study was to provide fish passage and distribution data to support decisions on long-term measures to enhance downstream passage at LOP and others dams in USACE’s Willamette Valley Project in response to the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. During the year-long study period - February 1, 2010 to January 31, 2011the objectives of the hydroacoustic evaluation of fish passage and distribution at LOP were to: 1. Estimate passage rates, run timing, horizontal distribution, and diel distribution at turbine penstock intakes for smolt-size fish. 2. Estimate passage rates, run timing and diel distribution at turbine penstock intakes for small-size fish. 3. Estimate passage rates and run timing at the regulating outlets for smolt-size fish. 4. Estimate vertical distribution of smolt-size fish in the forebay near the upstream face of the dam. The fixed-location hydroacoustic technique was used to accomplish the objectives of this study. Transducers (420 kHz) were deployed in each penstock intake, above each RO entrance, and on the dam face; a total of nine transducers (2 single-beam and 7 split-beam) were used. We summarize the findings from the hydroacoustic evaluation of juvenile salmonid passage and distribution at LOP during February 2010 through January 2011 as follows. • Fish passage rates for smolt-size fish (> ~90 mm) were highest during December-January and lowest in mid-summer through early fall. • During the entire study period, an estimated total of 142,463 fish ± 4,444 (95% confidence interval) smolt

  3. Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Lookout Point Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Hughes, James S.; Fischer, Eric S.; Trott, Donna M.; Ploskey, Gene R.

    2012-05-31

    Pacific Northwest National Laboratory evaluated juvenile salmonid passage and distribution at Lookout Point Dam (LOP) on the Middle Fork Willamette River for the U.S. Army Corps of Engineers, Portland District (USACE), to provide data to support decisions on long-term measures to enhance downstream passage at LOP and others dams in USACE's Willamette Valley Project. This study was conducted in response to the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. We conducted a hydroacoustic evaluation of juvenile salmonid passage and distribution at LOP during February 2010 through January 2011. Findings from this 1 year of study should be applied carefully because annual variation can be expected due to variability in adult salmon escapement, egg-to-fry and fry-to-smolt survival rates, reservoir rearing and predation, dam operations, and weather. Fish passage rates for smolt-size fish (> {approx}90 mm and < 300 mm) were highest during December-January and lowest in mid-summer through early fall. Passage peaks were also evident in early spring, early summer, and late fall. During the entire study period, an estimated total of 142,463 fish {+-} 4,444 (95% confidence interval) smolt-size fish passed through turbine penstock intakes. Of this total, 84% passed during December-January. Run timing for small-size fish ({approx}65-90 mm) peaked (702 fish) on December 18. Diel periodicity of smolt-size fish showing crepuscular peaks was evident in fish passage into turbine penstock intakes. Relatively few fish passed into the Regulating Outlets (ROs) when they were open in summer (2 fish/d) and winter (8 fish/d). Overall, when the ROs were open, RO efficiency (RO passage divided by total project passage) was 0.004. In linear regression analyses, daily fish passage (turbines and ROs combined) for smolt-size fish was significantly related to

  4. Wildlife and Wildlife Habitat Loss Assessment Summary at Lookout Point Dam and Reservoir Project, Middle Fork Willamette River, Oregon; 1985 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Bedrossian, K.L.; Noyes, J.H.

    1985-09-01

    A habitat based assessment was conducted of the US Army Corps of Engineers' Lookout Point Dam and Reservoir Project on the Middle Fork Willamette River, Oregon, to determine losses or gains resulting from development and operation of the hydroelectric related components of the project. Preconstruction, postconstruction, and recent vegetation cover types of the project site were mapped based on aerial photographs from 1944, 1956, and 1979, respectively. Vegetation cover types were identified within the affected area and acreages of each type at each period were determined. Seventeen wildlife target species were selected to represent a cross-section of species groups affected by the project. An interagency team evaluated the suitability of the habitat to support the target species at each time period. An evaluation procedure which accounted for both the quantity and quality of habitat was used to aid in assessing impacts resulting from the project. The Lookout Point Project extensively altered or affected 6790 acres of land and river in the Middle Fork Willamette River drainage. Impacts to wildlife centered around the loss of 724 acres of old-growth conifer forest and 118 acres of riparian habitat. Impacts resulting from the Lookout Point Project included the loss of winter range for Roosevelt elk, and the loss of year-round habitat for black-tailed deer, western gray squirrel, red fox, mink, beaver, ruffed grouse, ring-necked pheasant, California quail, spotted owl, and other nongame species. Bald eagle and osprey were benefitted by an increase in foraging habitat. The potential of the affected area to support wildlife was greatly altered as a result of the Lookout Point Project. Loses or gains in the potential of the habitat to support wildlife will exist over the life of the project.

  5. Hydrogeology of the Point Lookout Sandstone in the San Juan structural basin, New Mexico, Colorado, Arizona and Utah

    Science.gov (United States)

    Craigg, Steven D.; Dam, W.L.; Kernodle, J.M.; Thorn, C.R.; Levings, G.W.

    1990-01-01

    This report is one in a series resulting from the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) study of the San Juan structural basin that began in October 1984. Previous reports in the series describe the hydrogeology of the Dakota Sandstone (Craigg and others, 1989), Morrison Formation (Dam and others, 1990), Gallup Sandstone (Kernodle and others, 1989), Menefee Formation (Levings and others, 1990), and Cliff House Sandstone (Thorn and others, 1990), in the San Juan structural basin. The purposes of the RASA (Welder, 1986) are to: (1) Define and evaluate the aquifer system; (2) assess the effects of past, present, and potential ground-water use on aquifers and streams; and (3) determine the availability and quality of ground water. This report summarizes information on the geology and the occurrence and quality of water in the Point Lookout Sandstone, one of the primary water-bearing units in the regional aquifer system. Data used in this report were collected during the study or were derived from existing records in the U.S. Geological Survey's computerized National Water Information System (NWIS) data base, the Petroleum Information Corporation's database, and the Dwight's ENERGYDATA Inc. BRIN data base. Although all data available for the Point Lookout Sandstone were considered in formulating the discussions in the text, not all those data could be plotted on the illustrations. The San Juan structural basin is in New Mexico, Colorado, Arizona, and Utah and has an area of about 21,600 square miles (fig. 1). The structural basin is about 140 miles wide and about 200 miles long. The study area is that part of the structural basin that contains rocks of Triassic or younger age and, therefore, is less areally extensive than the structural basin. Triassic through Tertiary sedimentary rocks are emphasized in this study because the major aquifers in the basin are present in these rocks. The study area is about 140 miles wide (about the same as the

  6. Development of a study design and implementation plan to estimate juvenile salmon survival in Lookout Point Reservoir and other reservoirs of the Willamette Project, western Oregon

    Science.gov (United States)

    Kock, Tobias J.; Perry, Russell W.; Monzyk, Fred R.; Pope, Adam C.; Plumb, John M.

    2016-12-23

    Survival estimates for juvenile salmon and steelhead fry in reservoirs impounded by high head dams are coveted data by resource managers.  However, this information is difficult to obtain because these fish are too small for tagging using conventional methods such as passive-integrated transponders or radio or acoustic transmitters.  We developed a study design and implementation plan to conduct a pilot evaluation that would assess the performance of two models for estimating fry survival in a field setting.  The first model is a staggered-release recovery model that was described by Skalski and others (2009) and Skalski (2016).  The second model is a parentage-based tagging N-mixture model that was developed and described in this document.  Both models are conceptually and statistically sound, but neither has been evaluated in the field.  In this document we provide an overview of a proposed study for 2017 in Lookout Point Reservoir, Oregon, that will evaluate survival of Chinook salmon fry using both models.  This approach will allow us to test each model and compare survival estimates, to determine model performance and better understand these study designs using field-collected data.

  7. Seismic Analysis of Morrow Point Dam

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C R

    2002-04-01

    The main objective of this study is to perform nonlinear dynamic earthquake time history analyses on Morrow Point Dam, which is located 263 km southwest of Denver, Colorado. This project poses many significant technical challenges, one of which is to model the entire Morrow Point Dam/Foundation Rock/Reservoir system which includes accurate geology topography. In addition, the computational model must be initialized to represent the existing dead loads on the structure and the stress field caused by the dead loads. To achieve the correct dead load stress field due to gravity and hydrostatic load, the computer model must account for the manner in which the dams were constructed. Construction of a dam finite element model with the correct as-built geometry of the dam structure and simply ''turning on'' gravity in the computer model will generally lead to an incorrect initial stress field in the structure. The sequence of segmented lifts typical of dam construction has a significant impact on the static stress fields induced in the dam. In addition, the dam model must also account for the interaction between the adjacent dam segments across the dam contraction joints. As a result of these challenges, it was determined that a significant amount of code development was required in order to accurately simulate the motion of the dam structure. Modifications to the existing slide surfaces are needed to allow for appropriate modeling of the shear keys across the contraction joints. Furthermore, a model for hydrodynamic interaction was also implemented into NIKE3D and DYNA3D for fluid representation in the 3D dam system finite element model. Finally, the modeling of the 3D dam system results in a very large computational model, which makes it difficult to perform a static initialization using an implicit code. Traditionally, for these large models, the model has been initialized over a long time scale using an explicit code. However, recent advancements

  8. Nonlinear Seismic Analysis of Morrow Point Dam

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. THE IDENTIFICATION OF THE LOOKOUT POINTS WITH A ROLE IN THE TOURISM VALORISATION OF LANDSCAPE IN THE DISTRICT OF CICEU. VIEWSHED ANALYSIS

    Directory of Open Access Journals (Sweden)

    Alexandra-Camelia POTRA

    2016-11-01

    Full Text Available The increase of the visibility of a territory, in order to highlight the potential of the landscape, seen as a resource which can ensure the performance of various social-economic activities in a territory becomes achievable by arranging lookout points. Conducting the visibility analysis of such points is a common topic in the works of territorial planning, namely in terms of valorisation of landscapes and the visual impact assessment of their characteristics. The natural and the anthropic component of the District of Ciceu work together to create a valuable resource of the landscape, which are most often surprising by the presence of pitoresque valleys preserving the territorial specificities. The present study aims, in a first phase, that by the methods and tools specific to the onsite step (observation, mapping, to identify possible locations, including vestiges and historic buildings, suitable for arranging representative lookout points to present the elements of the landscape in the District of Ciceu. In order to achieve the visibility analysis, in order to highlight the assessment potential of district’s ”landscape” from the mapped lookout points, was resorted to ViewshedAnalysys method of the ArcGIS software. The use of the mapping leads to the materialization of theresults of the different cartographic representations, useful for the landscape recovery activities. The results of the study consist in generating the visibility areas of the lookout points, development of tourist routes that integrate the lookout points mapped on-site, namely to capitalize the landscape elements of the District of Ciceu.

  10. Montgomery Point Lock and Dam, White River, Arkansas

    Science.gov (United States)

    2016-01-01

    accurate and economical engineering solutions to coastal and hydraulic problems. This will strengthen and improve design criteria, enhance... Fischer , and J. Mewes. 2011. Montgomery Point Lock and Dam HSR model, White River miles 4.0 – 0.0; Hydraulic sediment response model investigation

  11. Dam Inventory - DAMS_1996_EPA_IN: Inventory of Dams in Indiana, Derived from EPA BASINS (United States Environmental Protection Agency, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — DAMS_1996_EPA_IN is a point shapefile developed by the USEPA BASINS 3.0 program and clipped by Bernardin, Lochmueller and Associates. Clips were performed using the...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Method of Fusion Diagnosis for Dam Service Status Based on Joint Distribution Function of Multiple Points

    Directory of Open Access Journals (Sweden)

    Zhenxiang Jiang

    2016-01-01

    Full Text Available The traditional methods of diagnosing dam service status are always suitable for single measuring point. These methods also reflect the local status of dams without merging multisource data effectively, which is not suitable for diagnosing overall service. This study proposes a new method involving multiple points to diagnose dam service status based on joint distribution function. The function, including monitoring data of multiple points, can be established with t-copula function. Therefore, the possibility, which is an important fusing value in different measuring combinations, can be calculated, and the corresponding diagnosing criterion is established with typical small probability theory. Engineering case study indicates that the fusion diagnosis method can be conducted in real time and the abnormal point can be detected, thereby providing a new early warning method for engineering safety.

  14. Individual Target Data-Collection Points Upstream of the Siltation Dam at Prairie Rose Lake, Shelby County, Iowa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Point coverage of bathymetry target points upstream of the siltation dam at Prairie Rose Lake in Shelby Co., Iowa. The U.S. Geological Survey conducted a...

  15. mpacts of Agricultural Non-point Pollution on Water-source Area in Songhua Dam

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.

  16. Expanding Lookout Capabilities for Architectural Analysis

    Science.gov (United States)

    Shick, B.

    SMC/SYSW/ENY's Lookout tool provides a M&S capability for architectural analysis. It models the contributions of ground and space-based assets in several mission threads and scenarios to quantify overall Space Situational Awareness (SSA) capability. Plotting performance results versus costs enables decision makers to identify and evaluate Best Value families of systems and combinations of architectures. Currently, SMC intends to use Lookout to impact the Fiscal Year 2012 budget programming cycle, the National SSA Initial Capabilities Document (ICD) and Architecture definition effort, planning for programs of record, and AFSPC & SMC leadership. Ultimately, Lookout will enable additional space superiority analysis. Previous Lookout work focused on modeling the metric tracking capabilities of the Space Surveillance Network (detecting and tracking) and proposed concepts to close identified collection shortfalls. SMC/SYSW/ENY leveraged some of the lessons learned in developing and implementing the metric tracking models to expand Lookout to develop an initial characterization capability, including non-resolved space object identification (SOI), imaging, and Foreign Instrumentation and Signals (FIS) Intelligence. Characterization collection phenomenologies added in FY08 and FY09 include mechanical tracking and phased array radars, visible telescopes, and signals collection. Lookout enables evaluating the characterization collections for quantity, quality, and timeliness. Capturing the Tasking, Collection, Processing, Exploitation, and Dissemination processes represent one of the biggest challenges in including characterization capabilities in mission thread and scenario-based analysis. The SMC/SYSW/ENY team met with several representatives of the community and held community-wide Technical Interchange Meetings. Based on feedback from these meetings, SMC created an infrastructure for modeling the tasking processes and scales to relate collection quality to intelligence

  17. Water temperature effects from simulated dam operations and structures in the Middle Fork Willamette River, western Oregon

    Science.gov (United States)

    Buccola, Norman L.; Turner, Daniel F.; Rounds, Stewart A.

    2016-09-14

    Significant FindingsStreamflow and water temperature in the Middle Fork Willamette River (MFWR), western Oregon, have been regulated and altered since the construction of Lookout Point, Dexter, and Hills Creek Dams in 1954 and 1961, respectively. Each year, summer releases from the dams typically are cooler than pre-dam conditions, with the reverse (warmer than pre-dam conditions) occurring in autumn. This pattern has been detrimental to habitat of endangered Upper Willamette River (UWR) Chinook salmon (Oncorhynchus tshawytscha) and UWR winter steelhead (O. mykiss) throughout multiple life stages. In this study, scenarios testing different dam-operation strategies and hypothetical dam-outlet structures were simulated using CE-QUAL-W2 hydrodynamic/temperature models of the MFWR system from Hills Creek Lake (HCR) to Lookout Point (LOP) and Dexter (DEX) Lakes to explore and understand the efficacy of potential flow and temperature mitigation options.Model scenarios were run in constructed wet, normal, and dry hydrologic calendar years, and designed to minimize the effects of Hills Creek and Lookout Point Dams on river temperature by prioritizing warmer lake surface releases in May–August and cooler, deep releases in September–December. Operational scenarios consisted of a range of modified release rate rules, relaxation of power-generation constraints, variations in the timing of refill and drawdown, and maintenance of different summer maximum lake levels at HCR and LOP. Structural scenarios included various combinations of hypothetical floating outlets near the lake surface and hypothetical new outlets at depth. Scenario results were compared to scenarios using existing operational rules that give temperature management some priority (Base), scenarios using pre-2012 operational rules that prioritized power generation over temperature management (NoBlend), and estimated temperatures from a without-dams condition (WoDams).Results of the tested model scenarios led

  18. Dam Safety Concepts

    NARCIS (Netherlands)

    Duricic, J.

    2014-01-01

    The majority of dams constructed in the world are dams that can be categorized as embankment dams. Throughout history we can point to many failures of dams, and embankment dams in particular. Nowadays it is clear that the goal to construct stable dams has not been achieved, even with advanced techno

  19. Dam Safety Concepts

    NARCIS (Netherlands)

    Duricic, J.

    2014-01-01

    The majority of dams constructed in the world are dams that can be categorized as embankment dams. Throughout history we can point to many failures of dams, and embankment dams in particular. Nowadays it is clear that the goal to construct stable dams has not been achieved, even with advanced

  20. Dam Safety Concepts

    NARCIS (Netherlands)

    Duricic, J.

    2014-01-01

    The majority of dams constructed in the world are dams that can be categorized as embankment dams. Throughout history we can point to many failures of dams, and embankment dams in particular. Nowadays it is clear that the goal to construct stable dams has not been achieved, even with advanced techno

  1. Temperature Effects of Point Sources, Riparian Shading, and Dam Operations on the Willamette River, Oregon

    Science.gov (United States)

    Rounds, Stewart A.

    2007-01-01

    Water temperature is an important factor influencing the migration, rearing, and spawning of several important fish species in rivers of the Pacific Northwest. To protect these fish populations and to fulfill its responsibilities under the Federal Clean Water Act, the Oregon Department of Environmental Quality set a water temperature Total Maximum Daily Load (TMDL) in 2006 for the Willamette River and the lower reaches of its largest tributaries in northwestern Oregon. As a result, the thermal discharges of the largest point sources of heat to the Willamette River now are limited at certain times of the year, riparian vegetation has been targeted for restoration, and upstream dams are recognized as important influences on downstream temperatures. Many of the prescribed point-source heat-load allocations are sufficiently restrictive that management agencies may need to expend considerable resources to meet those allocations. Trading heat allocations among point-source dischargers may be a more economical and efficient means of meeting the cumulative point-source temperature limits set by the TMDL. The cumulative nature of these limits, however, precludes simple one-to-one trades of heat from one point source to another; a more detailed spatial analysis is needed. In this investigation, the flow and temperature models that formed the basis of the Willamette temperature TMDL were used to determine a spatially indexed 'heating signature' for each of the modeled point sources, and those signatures then were combined into a user-friendly, spreadsheet-based screening tool. The Willamette River Point-Source Heat-Trading Tool allows the user to increase or decrease the heating signature of each source and thereby evaluate the effects of a wide range of potential point-source heat trades. The predictions of the Trading Tool were verified by running the Willamette flow and temperature models under four different trading scenarios, and the predictions typically were accurate

  2. Evaluating the Invasion of Red Cedar (Juniperus viriginiana) Downstream of Gavins Point Dam, Missouri National Recreational River

    Science.gov (United States)

    Greene, S.; Knox, J. C.

    2013-12-01

    Gavins Point Dam, the final dam on the main-stem Missouri River, alters downstream river form and function. Throughout a 59-mile downstream reach, the dam reduces overbank flooding and lowers the water surface by 1-3 meters. Under the dam-created hydro-geomorphic conditions, native cottonwood trees are unable to regenerate. The limited regeneration of native riparian cottonwoods, the lowered water surface, and the reduced overbank flooding creates a terrace environment within the riparian habitat. Consequently, red cedars, a native upland tree, are invading this new terrace-like riparian environment. To this end, we apply Bayesian statistical models to investigate patterns of red cedar riparian invasion and assess ecosystem function patterns along this flow-regulated reach. We set up plots within cottonwood stands along a 59-km reach downstream of Gavins Point Dam. Within each plot, we collected soil samples, litter samples, stem densities of trees, and collected cores of the largest cottonwood and largest red cedar in each plot. To assess influences of red cedar on soil indicators of ecosystem function and general patterns of ecosystem function within the study area, we measured organic carbon, nitrogen, pH, electrical conductivity, and hydrophobicity. To determine drivers and patterns of invasion and ecosystem function we conducted Bayesian linear regressions and means comparison tests. Red cedars existed along the floodplain prior to regulation. However, according to our tree age data and stem density data red cedars existed at a lower population than today. We found that 2 out of 565 red cedars established before the dam was completed. Also, we found no significant difference in soil properties between soils with established red cedar and soils with established cottonwood. By studying soil texture data, and interpreting fluvial geomorphic surfaces in the field and via aerial photography, we found soil texture generally reflects the type of fluvial surface

  3. GPS data collected for postconstruction hydrographic surveys of Missouri River downstream from Gavins Point Dam near river mile 761.4

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains land surface elevations on dry and wadeable portions of transects for the hydrographic surveys on the Missouri River below Gavins Point Dam...

  4. Postconstruction water velocity arrays collected at selected transects on the Missouri River downstream from Gavins Point Dam near River Mile 769.8

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains arrays of water velocity collected on selected transects of the Missouri River below Gavin's Point Dam near River Mile 769.8.

  5. 33 CFR 80.525 - Cape Lookout, NC to Cape Fear, NC.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cape Lookout, NC to Cape Fear, NC... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Fifth District § 80.525 Cape Lookout, NC to Cape Fear... southeast side of the Inlet. (g) Except as provided elsewhere in this section from Cape Lookout to Cape Fear...

  6. 49 CFR 214.349 - Training and qualification of watchmen/lookouts.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Training and qualification of watchmen/lookouts... Protection § 214.349 Training and qualification of watchmen/lookouts. (a) The training and qualification for roadway workers assigned the duties of watchmen/lookouts shall include, as a minimum, consideration of...

  7. 49 CFR 214.329 - Train approach warning provided by watchmen/lookouts.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train approach warning provided by watchmen... Protection § 214.329 Train approach warning provided by watchmen/lookouts. Roadway workers in a roadway work... or more watchmen/lookouts in accordance with the following provisions: (a) Train approach...

  8. Allegheny County Dam Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the point locations of dams in Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  9. National Dam Inspection Program. Edgewater Village (NDI-ID Number MD-83), Bush River Basin, Unnamed Tributary of Otter Point Creek, Harford County, Phase I Inspection Report,

    Science.gov (United States)

    1980-07-01

    features of the dam. d. Seismic Stability. The dam is located in Seismic Zone 1; and, based on visual observation, the static stability of the dam...EDGEWATER VILLAGE DAM ’LOGIC NAP OF HANFORD COUNTY,GELG MA PNPAIEI BY STATE OF MARYLAND,GEL YMA MARYLAND GEOLOGIC SURVEY,EL K PER& AH RMEL KLPER&_A

  10. Dams (National)

    Data.gov (United States)

    Department of Transportation — This map layer portrays major dams of the United States, including Puerto Rico and the U.S. Virgin Islands (NTAD 2015). The map layer was created by extracting dams...

  11. Visibility analysis of fire lookout towers in the Boyabat State Forest Enterprise in Turkey.

    Science.gov (United States)

    Kucuk, Omer; Topaloglu, Ozer; Altunel, Arif Oguz; Cetin, Mehmet

    2017-07-01

    For a successful fire suppression, it is essential to detect and intervene forest fires as early as possible. Fire lookout towers are crucial assets in detecting forest fires, in addition to other technological advancements. In this study, we performed a visibility analysis on a network of fire lookout towers currently operating in a relatively fire-prone region in Turkey's Western Black Sea region. Some of these towers had not been functioning properly; it was proposed that these be taken out of the grid and replaced with new ones. The percentage of visible areas under the current network of fire lookout towers was 73%; it could rise to 81% with the addition of newly proposed towers. This study was the first research to conduct a visibility analysis of current and newly proposed fire lookout towers in the Western Black Sea region and focus on its forest fire problem.

  12. H08548: NOS Hydrographic Survey , Point Lookout to Ragged Point, Maryland, 1960-07-18

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  13. Sensitivity analysis of non-point sources in a water quality model applied to a dammed low-flow-reach river.

    Science.gov (United States)

    Silva, Nayana G M; von Sperling, Marcos

    2008-01-01

    Downstream of Capim Branco I hydroelectric dam (Minas Gerais state, Brazil), there is the need of keeping a minimum flow of 7 m3/s. This low flow reach (LFR) has a length of 9 km. In order to raise the water level in the low flow reach, the construction of intermediate dikes along the river bed was decided. The LFR has a tributary that receives the discharge of treated wastewater. As part of this study, water quality of the low-flow reach was modelled, in order to gain insight into its possible behaviour under different scenarios (without and with intermediate dikes). QUAL2E equations were implemented in FORTRAN code. The model takes into account point-source pollution and diffuse pollution. Uncertainty analysis was performed, presenting probabilistic results and allowing identification of the more important coefficients in the LFR water-quality model. The simulated results indicate, in general, very good conditions for most of the water quality parameters The variables of more influence found in the sensitivity analysis were the conversion coefficients (without and with dikes), the initial conditions in the reach (without dikes), the non-point incremental contributions (without dikes) and the hydraulic characteristics of the reach (with dikes).

  14. Missouri River, Gavins Point Dam - Lewis and Clark Lake, Nebraska and South Dakota, Embankment Criteria and Performance Report.

    Science.gov (United States)

    1982-05-01

    DonoeCn vIH & COePS OF ENG11NEERS OMAHA NEFIRASKiA ENIBANKMENT CRITERIA AND PERFORMANCE REPORT P LATE A-2 I< _ I I- / LEWIS A CLARK LAKE Is --- 4"- C...i’d~~$o 4 cr , -,0 ,jb j I)OD W - - - -~~~~~~4 St 0-- St Ŕ j,0.’ (AtW MD. ISS orAL A]Wna Nvf.... Ash. -4N ൵IN POINT OW-LE WS AND CA LAK.E rA. 36

  15. Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

    NARCIS (Netherlands)

    Mienis, F.; Duineveld, G.C.A.; Davis, A.J.; Lavaleye, M.M.S.; Rosso, S.W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M.J.N.; de Haas, H.; Brooke, S.; van Weering, T.C.E.

    2014-01-01

    The Cape Lookout cold-water coral area off thecoast of North Carolina forms the shallowest and northernmostcold-water coral mound area on the Blake Plateau inthe NW Atlantic. Cold-water coral habitats near Cape Lookoutare occasionally bathed in the Gulf Stream, which is characterisedby oligotrophic

  16. 75 FR 3195 - Ochoco National Forest, Lookout Mountain Ranger District; Oregon; Mill Creek; Allotment...

    Science.gov (United States)

    2010-01-20

    ... Forest Service Ochoco National Forest, Lookout Mountain Ranger District; Oregon; Mill Creek; Allotment... Mountain Ranger District. These four allotments are: Cox, Craig, Mill Creek, and Old Dry Creek. The... responsible official will decide whether and how to reissue grazing permits in the Cox, Craig, Mill Creek...

  17. Challenges of high dam construction to computational mechanics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chuhan

    2007-01-01

    The current situations and growing prospects of China's hydro-power development and high dam construction are reviewed,giving emphasis to key issues for safety evaluation of large dams and hydro-power plants,especially those associated with application of state-of-the-art computational mechanics.These include but are not limited to:stress and stability analysis of dam foundations under external loads;earthquake behavior of dam-foundation-reservoir systems,mechanical properties of mass concrete for dams,high velocity flow and energy dissipation for high dams,scientific and technical problems of hydro-power plants and underground structures,and newly developed types of dam-Roll Compacted Concrete (RCC) dams and Concrete Face Rock-fill (CFR)dams.Some examples demonstrating successful utilizations of computational mechanics in high dam engineering are given,including seismic nonlinear analysis for arch dam foundations,nonlinear fracture analysis of arch dams under reservoir loads,and failure analysis of arch dam-foundations.To make more use of the computational mechanics in high dam engineering,it is pointed out that much research including different computational methods,numerical models and solution schemes,and verifications through experimental tests and filed measurements is necessary in the future.

  18. The technical key points of water conservancy engineering soil dam RCC construction%水利工程土坝碾压混凝土施工的技术要点

    Institute of Scientific and Technical Information of China (English)

    李骏杰

    2015-01-01

    This paper described the definition of water conservancy soil dam RCC construction technology,analyzed the raw materials control, warehouse check,technical scheme,quality monitoring and other construction measures and technical points of RCC construction,pointed out that the RCC construction had short work cycle,low cost,could directly use in local aggregates and other advantages.%阐述了水利工程土坝碾压混凝土施工技术的定义,分析了碾压混凝土施工原材料掌控、仓面检查、技术方案、质量监控等施工措施及技术要点,指出碾压混凝土坝施工具有工作周期短、成本低、可直接采用当地骨料等优越性。

  19. DETERMINING ITS QUALITY CONTROL POINTS FOR ROLLED EARTH FILL DAMS BASING ON WBS%基于WBS的碾压式土坝填筑质量控制要点探讨

    Institute of Scientific and Technical Information of China (English)

    蔚成良; 吴同强; 王莉; 吴壮

    2012-01-01

    对任何工程项目来说,质量都是决定项目成败的关键,而水利工程受水文、地质等条件影响,质量问题更加复杂多变,难以控制.本文正是针对于此,利用WBS对某碾压式土坝填筑工程进行结构分解,使整个工程的质量控制活动变得条理化.%Quality is the key for evaluation of the engineering projects. The issues of quality control within hydraulic projects become more complex and uncontrollable due to the hydrological and geological conditions. For solving these issues, WBS is involved in determining the quality control points for rolled earth fill dams and there for the quality control was aciereal.

  20. Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

    Science.gov (United States)

    Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Lavaleye, M. M. S.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M. J. N.; de Haas, H.; Brooke, S.; van Weering, T. C. E.

    2014-05-01

    The Cape Lookout cold-water coral area off the coast of North Carolina forms the shallowest and northernmost cold-water coral mound area on the Blake Plateau in the NW Atlantic. Cold-water coral habitats near Cape Lookout are occasionally bathed in the Gulf Stream, which is characterised by oligotrophic warm water and strong surface currents. Here, we present the first insights into the mound distribution and morphology, sedimentary environment and coral cover and near-bed environmental conditions as recorded by bottom landers from this coral area. The mounds occur between 320 and 550 m water depth and are characterised by high acoustic backscatter indicating the presence of hard structure. Three distinct mound morphologies were observed: (1) a mound with a flattened top at 320 m, (2) multi-summited mounds with a teardrop shape in the middle part of the area and (3) a single mound at 540 m water depth. Echosounder profiles show the presence of a strong reflector underneath all mound structures that forms the base of the mounds. This reflector cropped out at the downstream side of the single mound and consists of carbonate slabs. Video analysis revealed that all mounds are covered by Lophelia pertusa and that living colonies only occur close to the summits of the SSW side of the mounds, which is the side that faces the strongest currents. Off-mound areas were characterised by low backscatter and sediment ripples, indicating the presence of relatively strong bottom currents. Two bottom landers were deployed amidst the coral mounds between December 2009 and May 2010. Both landers recorded prominent events, characterised by large fluctuations in environmental conditions near the seabed as well as in the overlying water column. The period between December and April was characterised by several events of increasing temperature and salinity, coinciding with increased flow and near-bed acoustic backscatter. During these events temperature fluctuated by up to 9 °C within a

  1. Alpine dams

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  2. Iran funds dam completion

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Iran has signed a contract with unnamed foreign financiers for US$300M to fund two half-finished dam schemes, according to Tehran radio. The schemes are the Ostur dam in Mianeh in East Azerbaijan province and the Molla Sadra dam in Fars province. The Ostur dam will have a storage capacity of 2B m3 and a 160 MW hydro power station.

  3. Hoover Dam Learning Packet.

    Science.gov (United States)

    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…

  4. 40 meter ESRI binary grid of swath bathymetry of inner continental shelf south of Cape Hatteras, NC to Cape Lookout, NC (shatt, UTM Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  5. 40 meter ESRI binary grid of swath bathymetry of inner continental shelf south of Cape Hatteras, NC to Cape Lookout, NC (shatt, UTM Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  6. Dam removal: Listening in

    Science.gov (United States)

    Foley, Melissa M.; Bellmore, James; O'Connor, James E.; Duda, Jeff; East, Amy E.; Grant, Gordon G.; Anderson, Chauncey; Bountry, Jennifer A.; Collins, Mathias J.; Connolly, Patrick J.; Craig, Laura S.; Evans, James E.; Greene, Samantha; Magilligan, Francis J.; Magirl, Christopher S.; Major, Jon J.; Pess, George R.; Randle, Timothy J.; Shafroth, Patrick B.; Torgersen, Christian; Tullos, Desiree D.; Wilcox, Andrew C.

    2017-01-01

    Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (methods in the U.S.

  7. Dam to the Rescue

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Three Gorges Dam relieves the summer drought in south and central China,but may contribute to other problems The Three Gorges Dam played an important role in relieving China’s drought in central and eastern prov-inces that had been using increased water discharges from the Dam to irrigate dry farmlands facing the worst drought int he last 60 years in 2011.

  8. Crack status analysis for concrete dams based on measured entropy

    Institute of Scientific and Technical Information of China (English)

    WU BangBin; WU ZhongRu; CHEN Bo; SU HuaiZhi; BAO TengFei; WANG ShaoWei

    2016-01-01

    The integrity and safety of concrete dams are seriously affected by the existing cracks in dam bodies,and some serious cracks may cause dam failure or disaster.The propagation of cracks in concrete dams is accompanied by changes in energy distribution,which can be represented by changes in the structure's system entropy.Therefore,the entropy theory can be used in analyzing the behavior of dam cracks.Due to the randomness and locality of crack propagation,it is difficult to predict the location of cracks by traditional monitoring methods.To solve this problem,the influence of spatial positions of monitoring points on inspection zones is represented by a weight index,and the weight index is determined by the distance measure method proposed in this paper.Through the weighted linear fusion method,the entropy of multiple monitoring points is obtained for analyzing the behavior of dam cracks in the selected zones.Meanwhile,the catastrophe theory is used as the variation criterion of an entropy sequence in order to predict the instability time of dam cracks.Case studies are put forward on a high arch dam,and the fusion entropy is calculated according to the monitoring data from strain gauges.Results show that the proposed method can effectively predict the occurrence time and location of dam cracks regardless of the layout of monitoring instruments,and it is a new way to analyze the occurrence and propagation of dam cracks.

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

    Science.gov (United States)

    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

  10. Living with dams

    NARCIS (Netherlands)

    H.L.F. Saeijs (Henk); K.D. Schuijt (Kirsten)

    2002-01-01

    textabstractDams have proven their usefulness in preventing and mitigating floods, and water scarcity and generating electricity. They are indispensable in present society. But at the same time, they cause serious ecological, social and economical problems. Consequently we have to live with a dams

  11. Will Dam Removal Increase Nitrogen Flux to Estuaries?

    Directory of Open Access Journals (Sweden)

    Arthur J. Gold

    2016-11-01

    Full Text Available To advance the science of dam removal, analyses of functions and benefits need to be linked to individual dam attributes and effects on downstream receiving waters. We examined 7550 dams in the New England (USA region for possible tradeoffs associated with dam removal. Dam removal often generates improvements for safety or migratory fish passage but might increase nitrogen (N flux and eutrophication in coastal watersheds. We estimated N loading and removal with algorithms using geospatial data on land use, stream flow and hydrography. We focused on dams with reservoirs that increase retention time at specific points of river reaches, creating localized hotspots of elevated N removal. Approximately 2200 dams with reservoirs had potential benefits for N removal based on N loading, retention time and depth. Across stream orders, safety concerns on these N removal dams ranged between 28% and 44%. First order streams constituted the majority of N removal dams (70%, but only 3% of those were classified as high value for fish passage. In cases where dam removal might eliminate N removal function from a particular reservoir, site-specific analyses are warranted to improve N delivery estimates and examine alternatives that retain the reservoir while enhancing fish passage and safety.

  12. Dams: Pros and Cons

    African Journals Online (AJOL)

    Steve

    The Dam was built for the main purpose of water supply to university community. Data on .... The decision on who is to participate in a full EIA on a water ... METHOD AND MATERIALS ..... Development”, Encyclopedia of Life Support Systems,.

  13. Accuracy Analysis of a Dam Model from Drone Surveys

    OpenAIRE

    Elena Ridolfi; Giulia Buffi; Sara Venturi; Piergiorgio Manciola

    2017-01-01

    This paper investigates the accuracy of models obtained by drone surveys. To this end, this work analyzes how the placement of ground control points (GCPs) used to georeference the dense point cloud of a dam affects the resulting three-dimensional (3D) model. Images of a double arch masonry dam upstream face are acquired from drone survey and used to build the 3D model of the dam for vulnerability analysis purposes. However, there still remained the issue of understanding the real impact of a...

  14. Dam safety in British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, H.M.; Round, R.P.D.

    1978-01-01

    Many dams in British Columbia were built before 1900, and a comprehensive inspection and surveillance program has been developed. The background and implementation of this program are described. Topics discussed include program responsibilities, classification of dams, organization, the dam safety program, and coordination with other agencies. (PMA)

  15. Integrated Analysis of the Formation Mechanism of Cracks in a Concrete Dam Using Microseismic Monitoring and Numerical Simulation

    OpenAIRE

    Gang He; Biao Li; Xuben Wang; Nuwen Xu

    2016-01-01

    The dam of Guanyinyan hydropower station is composed of a concrete gravity dam in the left bank and a rockfill dam in the right bank. During the operation of the hydropower station, several surface cracks occurred in the concrete gravity dam, which threatened the stability of the dam. To evaluate the evolution trend of the cracks and forecast the potential risk of the dam, the microseismic (MS) monitoring technique and finite-element method were used. First, the concrete three-point bending f...

  16. Thermal effects of dams in the Willamette River basin, Oregon

    Science.gov (United States)

    Rounds, Stewart A.

    2010-01-01

    Methods were developed to assess the effects of dams on streamflow and water temperature in the Willamette River and its major tributaries. These methods were used to estimate the flows and temperatures that would occur at 14 dam sites in the absence of upstream dams, and river models were applied to simulate downstream flows and temperatures under a no-dams scenario. The dams selected for this study include 13 dams built and operated by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Project, and 1 dam on the Clackamas River owned and operated by Portland General Electric (PGE). Streamflows in the absence of upstream dams for 2001-02 were estimated for USACE sites on the basis of measured releases, changes in reservoir storage, a correction for evaporative losses, and an accounting of flow effects from upstream dams. For the PGE dam, no-project streamflows were derived from a previous modeling effort that was part of a dam-relicensing process. Without-dam streamflows were characterized by higher peak flows in winter and spring and much lower flows in late summer, as compared to with-dam measured flows. Without-dam water temperatures were estimated from measured temperatures upstream of the reservoirs (the USACE sites) or derived from no-project model results (the PGE site). When using upstream data to estimate without-dam temperatures at dam sites, a typical downstream warming rate based on historical data and downstream river models was applied over the distance from the measurement point to the dam site, but only for conditions when the temperature data indicated that warming might be expected. Regressions with measured temperatures from nearby or similar sites were used to extend the without-dam temperature estimates to the entire 2001-02 time period. Without-dam temperature estimates were characterized by a more natural seasonal pattern, with a maximum in July or August, in contrast to the measured patterns at many of the tall dam sites

  17. Isopach grid of the Quaternary sediment thickness, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q0thick, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. 4 meter sidescan-sonar GeoTIFF image of inner shelf from Cape Hatteras, NC to Cape Lookout, NC (composite_shatt.tif, UTM, Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  19. 4 meter sidescan-sonar GeoTIFF image of inner shelf with stretched histogram, from Cape Hatteras, NC to Cape Lookout, NC (composite_shatt_str.tif, UTM, Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  20. Isopach grid of the Quaternary sediment thickness, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q0thick, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  1. 4 meter sidescan-sonar GeoTIFF image of inner shelf with stretched histogram, from Cape Hatteras, NC to Cape Lookout, NC (composite_shatt_str.tif, UTM, Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  2. 4 meter sidescan-sonar GeoTIFF image of inner shelf from Cape Hatteras, NC to Cape Lookout, NC (composite_shatt.tif, UTM, Zone 18N, WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  3. Determination of metals in water from Billings dam, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Talita; Sarkis, Jorge E.S.; Ulrich, Joao C.; Yamaguishi, Renata Bazante, E-mail: taoliveira@ipen.br, E-mail: jesarkis@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Menezes, Luciana Carvalho Bezerra de; Castro, Paula Maria Genova de; Monteiro Junior, Adalberto Jose; Maruyama, Lidia Sumile, E-mail: lcbm@usp.br [Instituto de Pesca, (IP/SAA-SP), Sao Paulo, SP (Brazil). Secretaria da Agricultura e Abastecimento do Estado de Sao Paulo

    2013-07-01

    The Billings reservoir, located in Sao Paulo, Brazil, is used for several purposes such as: water supply, electric generation, fishing and leisure. Although considered an area of environmental protection, in recent years the dam has suffered diverse environmental aggressions including the release of toxic metals. This study presents a recent evaluation of metal contents along the Dam. Samples were collected every three months during the period of winter 2009 to summer 2010. Samples were collected in thirteen points along of the dam, as follows: Rio dos Porcos (Point 1), Summit Control (Point 2), Ilha do Bigua (Point 3), Casa Caida (Point 4), Barragem (Point 5), Foz de Taquacetuba (Point 6), Braco Borore (Point 7), Foz de Borore (Point 8), Alvarenga (Point 9), Pedreira (Point 10), Borore's Margin (Point 11), Capivari I's Margin (Point 12) and Capivari II's Margin (Point 13). The determination of Al, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn was performed by using high resolution inductively coupled plasma mass spectrometer (HR-ICPMS). The methodology has been validated using certified reference material Riverine Water Reference Material for Trace Metals provided by National Research Council Canada (NRCC). The sampling points located in the Pedreira, Borore's Margin, Alvarenga, Barragem Taquacetuba, Casa Caida e Ilha do Bigua presented the highest concentrations. The level for Fe, Cu and Ni were higher than the ones reported in the literature and above the limit set by CONAMA 2914/201. (author)

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

    Science.gov (United States)

    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.

  5. USGS Dam Removal Science Database

    Science.gov (United States)

    Bellmore, J. Ryan; Vittum, Katherine; Duda, Jeff J.; Greene, Samantha L.

    2015-01-01

    This database is the result of an extensive literature search aimed at identifying documents relevant to the emerging field of dam removal science. In total the database contains 179 citations that contain empirical monitoring information associated with 130 different dam removals across the United States and abroad. Data includes publications through 2014 and supplemented with the U.S. Army Corps of Engineers National Inventory of Dams database, U.S. Geological Survey National Water Information System and aerial photos to estimate locations when coordinates were not provided. Publications were located using the Web of Science, Google Scholar, and Clearinghouse for Dam Removal Information.

  6. 33 CFR 334.200 - Chesapeake Bay, Point Lookout to Cedar Point; aerial and surface firing range and target area, U...

    Science.gov (United States)

    2010-07-01

    ... degrees 09 minutes 26 seconds identified as Hannibal Target. (3) The regulations. Nonexplosive projectiles and bombs will be dropped at frequent intervals in the target areas. Hooper and Hannibal target...

  7. The dam design of Three Gorges Project

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaomao; Xu Linxiang; Liao Renqiang

    2011-01-01

    The dam of Three Gorges Project is a concrete gravity dam with the crest elevation of 185 m, the maximum height of 181 m and dam axis length of 2 309.5 m. The dam consists of spillway, powerhouse, non-over flow, ship-lift, temporary ship-lock, left diversion wall and longitudinal cofferdam blocks. Some key techniques relating to dam structure design are presented, including hydraulics of flood discharge structure, dam joint design, layout and structural type of penstock, deep anti-sliding stability of dam foundation, reconstruction of temporary ship-lock and closed drainage and pumping of dam foundation.

  8. Tarbela Dam Project

    Energy Technology Data Exchange (ETDEWEB)

    Khan, B.A. [WAPDA Tarbela Dam Project (Pakistan); Ahmad, W. [Siemens Pakistan Ltd., Islamabad (Pakistan)

    1999-07-01

    Construction of one of the world's largest water resource development project is discussed. The Tarbela project is built on the Indus River, (itself one of the largest rivers of the world) and consists of a 9,000 feet long and 465 feet high earth and rockfill embankment across the entire width of the river with two spillways cutting through the left bank. On the left bank valley there are two auxiliary embankment dams to close the gap. A total of five tunnels, each a mile long, have been constructed for irrigation releases and power generation. Electricity is being generated by two power generating plants constructed on three of these tunnels. They have a generating capacity of 3,478 MW, supplying 40 per cent of all Pakistani demand. Several 'firsts' are identified. For example, the dam is the world's largest, containing over 200 million cubic yards of earth and rock, as are the five tunnels (14 meters in diameter), as well as the outlet gates. The energy release by the water gushing through the five tunnels at maximum level is more than 13 million KW, approximately equivalent to 10 million horsepower. 1 ref.

  9. Earthquake response of concrete arch dams with layered rock foundation in time domain with a case study of an arch dam in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Barikani, A. [Tabriz Univ., Tehran (Iran, Islamic Republic of). Dept. of Civil Engineering; Hashemiravan, M. [Varamin Azad Univ., Tehran (Iran, Islamic Republic of). Dept. of Civil Engineering

    2006-07-01

    This study examined the dynamic behaviour of an arch dam and the interactions between the dam and its layered rock foundation. The seismic response of the Amir Kabir dam located in Iran was investigated using a 3-D finite element model. The rock foundation of the dam was divided into 3 areas: high resistance rock, medium resistance rock, and low resistance rock. The hydrodynamic effects of water were modelled using an added mass method with concentrate masses in nodes of elements on the upstream face of the dam body. Earthquake response of the dam was demonstrated using a time history of displacement at the dam crest, contours of maximum tensile stresses, and maximum pressure stresses on the upstream and downstream face of the dam. The study also examined issues concerning tensile cracks that occurred as a result of an actual earthquake. Results showed that the maximum tensile stress in the upstream face of the dam was 2.5 times more than allowable limits for tensile stress in concrete. The maximum pressure stress was lower than allowable limits. A comparison between the time history of the principal stresses at different points of the dam demonstrated that maximum tensile stress occurred in the middle of the dam. However pressure was highest near the foundation level. Results showed that the tensile cracks in the dam crest area were caused by the excessive amounts of tensile stress. It was also concluded that the earthquake used in the study was in the design basis earthquake (DBE) category, with a return period of approximately 200 years. 7 refs., 5 tabs., 10 figs.

  10. Key technical problems of extra-high concrete faced rock-fill dam

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper summarizes the main technical points related to 100 m-height-scale concrete faced rock-fill dams and analyzes the main problems and their causes occurring during construction of 200 m-height-scale concrete faced rock-fill dams.This paper has raised the key technical problems which need to study for construction of 300 m-height-scale concrete faced rock-fill dams based on the main experiences on the extra-high concrete faced rock-fill dams built after the year of 2000.

  11. Determination of Seepage and Analysis of Earth Dams (Case Study: Karkheh Dam)

    OpenAIRE

    A. Kamanbedast; M. Shahosseini

    2011-01-01

    Because of the increasing trend of building dam throughout Iran; it is necessary to optimize dam buildings and operations. Dam or Hydropower industry has two types of buildings; normally: (1) Concrete dams (2) Embankment (earth) dams. Generally, scientists and engineers use different methods to enhance safety and decrease any errors in calculation due to maintenance of water storage especially hydro structure of the dam. It is necessary to investigate the dam seepage control; commonly use...

  12. The Changing Political Dynamics of Dam Building on the Mekong

    Directory of Open Access Journals (Sweden)

    Philip Hirsch

    2010-06-01

    Full Text Available This paper explores political dynamics surrounding dam building in the Mekong river basin, prior to, and following, the World Commission on Dams (WCD. Since the 1950s, dam building in the Mekong river basin has been enmeshed in a complex and shifting geopolitical and eco-political landscape. The broad geopolitical sweep of US hegemony, Cold War, regional rapprochement and the rise of China has been superimposed on eco-political shifts between modernist belief in progress as mastery over nature, concerns of global and national environmental movements over dams and their impacts, and a galvanised Mekong environmentalism. During the first decade of the 21st century, mainstream dams on the Lower Mekong have returned to the agenda after having almost disappeared in favour of tributary projects. The growing strength and assertiveness of regional economic players has fundamentally altered the context of energy demand, planning and investment. New sources of finance have relocated the points of political leverage. Environment has been mustered in favour of, as well as in opposition to, dam construction in the contexts of climate-change discourses, protected-area linkage with dam projects, and an industry push for sustainability protocols and certification. Despite the Mekong being one of its focal basins, WCD has not played a prominent role in this transformed arena, yet many of the social and environmental concerns, stakeholder-based processes and safeguard-oriented approaches to hydropower planning that WCD brought to the fore have persisted in the wider ethos of politics around dams in the region.

  13. Gene Wash and Copper Basin Dams are surviving alkali-aggregate reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hill, C.J.

    1995-12-31

    Gene Wash and Copper Basin Dams were constructed in 1937 and 1938, and are owned and operated by the Metropolitan Water District of Southern California (MWD). The dams are located in San Bernardino County, California, close to the Colorado River, and very close to the easternmost point of California. They form two intermediate storage facilities on the Colorado River Aqueduct system which conveys water from Lake Havasu to the Los Angeles and San Diego areas. The locations of the dams are shown. Gene Wash Dam is a concrete arch structure, with a maximum height of arch of 131 feet. There is a gravity thrust block on the right abutment and the total crest length is 430 feet. Copper Basin Dam is a concrete arch dam with a maximum height of arch of 187 feet and a crest length of 253 feet. Plans, elevations and sections for both dams. The dams are in the Whipple Mountains at the eastern edge of the Mojave Desert. Between June and October, maximum temperatures usually exceed 100 degrees Farenheit, while daily low temperatures in this period are generally in the 60`s and 70`s. Winter temperatures are mild, with daytime highs in the 70`s and 80`s, and lows only occasionally below freezing. The area is arid, with total annual rainfall generally between two and ten inches. Both dams were built in desert washes with no permanent flow. The foundation for both structures is a strong, erosion-resistant, red-brown, non-marine sandstone and conglomerate of Tertiary age known as the Copper Basin Formation (Buwalda, 1937). Spillways for both dams are ungated ogee crests, which are separate from the dams. Gene Wash Dam and Copper Basin Dam are geographically close together, are of similar design, and were constructed at the same time, using the same materials. Their performance since construction, not surprisingly, has been similar.

  14. A Hidden-Removal Model of Dam Perspective Drawing

    Institute of Scientific and Technical Information of China (English)

    WANG Zi-ru; ZHOU Hui-cheng; LI Ming-qiu

    2011-01-01

    Aming at water conservancy project visualization, a hidden-removal method of dam perspective drawings is realized by building a hidden-removal mathematical model for overlapping points location to set up the hidden relationship among point and plane, plane and plane in space. On this basis, as an example of panel rockfill dam, a dam hidden-removal perspective drawing is generated in different directions and different visual angles through adapting VC++ and OpenGL visualizing technology. The results show that the data construction of the model is simple which can overcome the disadvantages of considerable and complicated calculation. This method also provides the new means to draw hidden-removal perspective drawings for those landforms and ground objects.

  15. Landscape Evolution Modelling of naturally dammed rivers

    NARCIS (Netherlands)

    Gorp, van W.; Temme, A.J.A.M.; Baartman, J.E.M.; Schoorl, J.M.

    2014-01-01

    Natural damming of upland river systems, such as landslide or lava damming, occurs worldwide. Many dams fail shortly after their creation, while other dams are long-lived and therefore have a long-term impact on fluvial and landscape evolution. This long-term impact is still poorly understood and

  16. Landscape Evolution Modelling of naturally dammed rivers

    NARCIS (Netherlands)

    van Gorp, Wouter; Temme, Arnaud J. A. M.; Baartman, Jantiene E. M.; Schoorl, Jeroen M.

    2014-01-01

    Natural damming of upland river systems, such as landslide or lava damming, occurs worldwide. Many dams fail shortly after their creation, while other dams are long-lived and therefore have a long-term impact on fluvial and landscape evolution. This long-term impact is still poorly understood and la

  17. 76 FR 12094 - Whitman River Dam, Inc.

    Science.gov (United States)

    2011-03-04

    ... Federal Energy Regulatory Commission Whitman River Dam, Inc. Notice of Application Tendered for Filing.... Applicant: Whitman River Dam, Inc. e. Name of Project: Crocker Dam Hydro Project. f. Location: On the... analysis at this time. n. The Crocker Dam Hydro Project would consist of: (1) The existing...

  18. FORMATION AND FAILURE OF NATURAL DAMS.

    Science.gov (United States)

    Costa, John E.; Schuster, Robert L.

    1988-01-01

    Of the numerous kinds of dams that form by natural processes, dams formed from landslides, glacial ice, and late-neoglacial moraines present the greatest threat to people and property. Landslide dams form a wide range of physiographic settings. The most common types of mass movements that form landslide dams are rock and debris avalanches; rock and soil slumps and slides; and mud, debris, and earth flows. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snowmelt and earthquakes. Natural dams may cause upstream flooding as the lake rises and downstream flooding as a result of failure of the dam. Although data are few, for the same potential energy at the dam site, downstream flood peaks from the failure of glacier-ice dams are smaller than those from landslide, moraine, and constructed earth-fill and rock-fill dam failures.

  19. Theory and methods of global stability analysis for high arch dam

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The global stability of high arch dam is one of the key problems in the safety study of arch dams,but no feasible method with theoretical basis is available.In this paper,based on the stability theory of mechanical system,it is demonstrated that the global failure of high arch dams belongs to a physical instability starting from local strength failure,which is the extreme point instability according to the characteristics of load-displacement curve obtained from the failure process of dam-foundation system. So the global failure of dam-foundation system should be studied with the stability theory of mechanical system.It is also pointed out that the current stability analysis methods used in engineering are consistent with the stability theory,but not established according to the mechanical system stability theory directly.A perfect method can be obtained through the study of physical disturbance equations.

  20. Big Lake Dam Inspection Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes an inspection of the Big Lake Dam that was done in September of 1983. The inspection did not reveal any conditions that constitute and...

  1. Accuracy Analysis of a Dam Model from Drone Surveys.

    Science.gov (United States)

    Ridolfi, Elena; Buffi, Giulia; Venturi, Sara; Manciola, Piergiorgio

    2017-08-03

    This paper investigates the accuracy of models obtained by drone surveys. To this end, this work analyzes how the placement of ground control points (GCPs) used to georeference the dense point cloud of a dam affects the resulting three-dimensional (3D) model. Images of a double arch masonry dam upstream face are acquired from drone survey and used to build the 3D model of the dam for vulnerability analysis purposes. However, there still remained the issue of understanding the real impact of a correct GCPs location choice to properly georeference the images and thus, the model. To this end, a high number of GCPs configurations were investigated, building a series of dense point clouds. The accuracy of these resulting dense clouds was estimated comparing the coordinates of check points extracted from the model and their true coordinates measured via traditional topography. The paper aims at providing information about the optimal choice of GCPs placement not only for dams but also for all surveys of high-rise structures. The knowledge a priori of the effect of the GCPs number and location on the model accuracy can increase survey reliability and accuracy and speed up the survey set-up operations.

  2. Accuracy Analysis of a Dam Model from Drone Surveys

    Directory of Open Access Journals (Sweden)

    Elena Ridolfi

    2017-08-01

    Full Text Available This paper investigates the accuracy of models obtained by drone surveys. To this end, this work analyzes how the placement of ground control points (GCPs used to georeference the dense point cloud of a dam affects the resulting three-dimensional (3D model. Images of a double arch masonry dam upstream face are acquired from drone survey and used to build the 3D model of the dam for vulnerability analysis purposes. However, there still remained the issue of understanding the real impact of a correct GCPs location choice to properly georeference the images and thus, the model. To this end, a high number of GCPs configurations were investigated, building a series of dense point clouds. The accuracy of these resulting dense clouds was estimated comparing the coordinates of check points extracted from the model and their true coordinates measured via traditional topography. The paper aims at providing information about the optimal choice of GCPs placement not only for dams but also for all surveys of high-rise structures. The knowledge a priori of the effect of the GCPs number and location on the model accuracy can increase survey reliability and accuracy and speed up the survey set-up operations.

  3. Bathymetry data for the pre-construction survey of the Emergent Sandbar Habitat project at river mile 761.4 downstream from Gavins Point dam on the Missouri River.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geospatial data set contains the points collected by the echosounder on transects in the downstream project reach surrounding the construction area at River...

  4. Bathymetry data for the pre-construction survey of the Emergent Sandbar Habitat project at river mile 769.8 downstream from Gavins Point Dam on the Missouri River.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geospatial data set contains the points collected by the echosounder on transects in the upstream project reach surrounding the construction area at River Mile...

  5. Bathymetry data for the post-construction survey of the Emergent Sandbar Habitat project at river mile 769.8 downstream from Gavins Point Dam on the Missouri River.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geospatial data set contains the points collected by the echosounder on transects in the upstream project reach surrounding the construction area at River Mile...

  6. Bathymetry data for the post-construction survey of the Emergent Sandbar Habitat project at river mile 761.4 downstream from Gavins Point dam on the Missouri River.

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This geospatial data set contains the points collected by the echosounder on transects in the downstream project reach surrounding the construction area at River...

  7. Geophysical evaluation of the Success Dam foundation, Porterville, California

    Science.gov (United States)

    Hunter, L.E.; Powers, M.H.; Haines, S.; Asch, T.; Burton, B.L.; Serafini, D.C.

    2006-01-01

    Success Dam is a zonedearth fill embankment located near Porterville, CA. Studies of Success Dam by the recent Dam Safety Assurance Program (DSAP) have demonstrated the potential for seismic instability and large deformation of the dam due to relatively low levels of earthquake shaking. The U.S. Army Corps of Engineers conducted several phases of investigations to determine the properties of the dam and its underlying foundation. Detailed engineering studies have been applied using a large number of analytical techniques to estimate the response of the dam and foundation system when subjected to earthquake loading. Although a large amount of data have been acquired, most are 'point' data from borings and results have to be extrapolated between the borings. Geophysical techniques were applied to image the subsurface to provide a better understanding of the spatial distribution of key units that potentially impact the stability. Geophysical investigations employing seismic refraction tomography, direct current (DC) resistivity, audio magnetotellurics (AMT) and self-potential (SP) were conducted across the location of the foundation of a new dam proposed to replace the existing one. Depth to bedrock and the occurrence of beds potentially susceptible to liquefaction were the focus of the investigations. Seismic refraction tomography offers a deep investigation of the foundation region and looks at compressional and shear properties of the material. Whereas resistivity surveys determines conductivity relationships in the shallow subsurface and can produce a relatively high-resolution image of geological units with different electrical properties. AMT was applied because it has the potential to look considerably deeper than the other methods, is useful for confirming depth to bedrock, and can be useful in identifying deep seated faults. SP is a passive electrical method that measures the electrical streaming potential in the subsurface that responds to the movement of

  8. Conflicts Associated with Dam Removal in Sweden

    Directory of Open Access Journals (Sweden)

    Anna G. C. Lejon

    2009-12-01

    Full Text Available The increasing number of deteriorating old dams that need renovation or have lost their function make dam removal a viable management option. There are at least four major reasons for dam removal: safety, law and policy, economy, and ecology. Here we discuss 17 Swedish dams that were recently considered for removal. Because dam removal usually causes controversy, dam removal initiatives may succeed, fail, or result in a compromise such as a bypass channel for migrating fish. We identify and discuss three major obstructions to dam removal: funding, cultural-historical values, and threatened species. To facilitate dam removal, the reasons for, and the effects of, dam removal must be carefully explained, and the public and stakeholders must be kept informed. In complicated cases in which compromise solutions may be the most feasible outcome, the integration of the knowledge of different stakeholders is crucial. The involvement of diverse stakeholders increases their willingness to find compromises, thus avoiding conflicts and failures.

  9. EXAMINATION AND TESTING OF CRANE BEAMS OF AN OVERFLOW DAM

    Directory of Open Access Journals (Sweden)

    Kholopov Igor' Serafimovich

    2012-10-01

    Full Text Available The following conclusions were made upon completion of the testing of crane beams: The lowest rigidity is demonstrated by welded beams exposed to temporary mobile loads; the maximal buckling caused by temporary mobile loads is equal to 12 mm, or 1/1,1790 of the span; the rigidity of crane beams of an overflow dam meets the requirements set by Section E2.1 of Construction Rules 20.13330.2011 "Loads and Actions". In general, the authors state that the crane beams of the span structure of the overflow dam are in a serviceable operating condition, according to their opinion issued upon completion of examination and testing procedures. The recommendation is to regularly tighten screw nuts and to install high-strength bolts in the points of missing rivets. The authors also recommend applying a rust-proofing coating to all metal structures of the dam spans.

  10. Damming the rivers of the Amazon basin

    Science.gov (United States)

    Latrubesse, Edgardo M.; Arima, Eugenio Y.; Dunne, Thomas; Park, Edward; Baker, Victor R.; D'Horta, Fernando M.; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A.; Ribas, Camila C.; Norgaard, Richard B.; Filizola, Naziano; Ansar, Atif; Flyvbjerg, Bent; Stevaux, Jose C.

    2017-06-01

    More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin’s floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.

  11. Dam risk assistant analysis system design

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to reduce the labor intensity and task difficulty of dam risk analysis and to meet the actual requirement of dam risk analysis,it is necessary to establish a dam risk assistant analysis system.The program structure and the implementation ways of the dam risk assistant analysis system are analyzed,and a procedural framework with "three-tier and multi-database" structure and "level structure" is established.The concept of dam risk assessment system modular development is proposed and the coupled mode of function module and data is improved.Finally,the dam risk assistant analysis system is developed using Delphi visual programming language.

  12. Application of the Periodic Average System Model in Dam Deformation Analysis

    Directory of Open Access Journals (Sweden)

    Yueqian Shen

    2015-01-01

    Full Text Available Dams are among the most important hydraulic engineering facilities used for water supply, flood control, and hydroelectric power. Monitoring of dams is crucial since deformation might have occurred. How to obtain the deformation information and then judge the safe conditions is the key and difficult problem in dam deformation monitoring field. This paper proposes the periodic average system model and creates the concept of “settlement activity” based on the dam deformation issue. Long-term deformation monitoring data is carried out in a pumped-storage power station, this model combined with settlement activity is used to make the single point deformation analysis, and then the whole settlement activity profile is drawn by clustering analysis. Considering the cumulative settlement value of every point, the dam deformation trend is analyzed in an intuitive effect way. The analysis mode of combined single point with multipoints is realized. The results show that the key deformation information of the dam can be easily grasped by the application of the periodic average system model combined with the distribution diagram of settlement activity. And, above all, the ideas of this research provide an effective method for dam deformation analysis.

  13. Putting Roman Dams in Context: a Virtual Approach

    Science.gov (United States)

    Decker, M. J.; Du Vernay, J. P.; Mcleod, J. B.

    2017-08-01

    innovative perspective on a long time studied monument. In this paper it will be explored how deploying recent computer technologies to the Roman dam at Consuegra can advance our understanding of the history of local and regional landscape change and the technology of water management. In summer 2016, the dam has been documented with terrestrial laser scanning with two FARO Focus 3D x330 and aerial photogrammetry image capturing with a DJI Phantom 4 drone. Data was processed in various 3D software applications to generate 3D representations of the dam including 3D point clouds, animations, and meshed models.

  14. Douglas County Dam Breach Inundation Areas

    Data.gov (United States)

    Kansas Data Access and Support Center — Dam breach analysis provides a prediction of the extent and timing of flooding from a catastrophic breach of the dams. These results are sufficient for developing...

  15. VT High Risk Dam Inundation Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) Preliminary release Storm-Day dam inundation areas digitized from various source Emergency Action Plans. These dams were prioritized for...

  16. Dams and Obstructions along Iowa's Canoe Routes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This dataset represents obstruction to canoe and boat users of the canoe routes of Iowa. This may represent actual dams, rock dams (natural or man made), large...

  17. 78 FR 53494 - Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams

    Science.gov (United States)

    2013-08-29

    ... Dam Safety Modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams AGENCY: Tennessee... preferred alternative in its final environmental impact statement (EIS) for the dam safety modifications at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams. The notice of availability (NOA) of the...

  18. Studies on the detection of leaks from Tapacura dam

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Marco O.A.; Andrade Lima, Ricardo de; Antonino, Antonio C.D.; Villar, Heldio P.; Oliveira Lira, Carlos A.B. de [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear; Badeira, Jefferson V. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Viana, Afonso A. [Companhia Pernambucana de Saneamento e Agua, Recife, PE (Brazil); Plata-Bedmar, Antonio [Centro de Estudios y Experimentaciones de Obras Publicas (Spain); Garcia-Agudo, Edmundo [International Atomic Energy Agency, Vienna (Austria)

    1997-12-01

    One of the many applications of stable isotope analyses is in hydrological studies. as the isotope concentration of elements in water vary as a result of fractionation due to physicochemical processes, each water has its own fingerprints, so that identification of its origin is made possible. This technique has been used in the investigation of the possible leaks through the geologic formation underneath the Tapacura Dam, near Recife, Brazil. Samples were collected from the reservoir and from several collection points downstream. These samples have been analysed for their deuterium, {sup 18} O and {sup 13} C concentrations. The comparison between results from these analyses indicated that water from the reservoir and from the other collection points had distinct origins. These finding were corroborated from standard chemical analyses and tracer studies, thus pointing to the absence of any significant underflow at the Tapacura Dam. (author). 4 refs., 1 fig., 4 tabs.

  19. EXPERIMENTAL STUDY OF DAM-BREAK FLOW IN CASCADE RESERVOIRS WITH STEEP BOTTOM SLOPE

    Institute of Scientific and Technical Information of China (English)

    XUE Yang; XU Wei-lin; LUO Shu-jing; CHEN Hua-yong; LI Nai-wen; XU Ling-jun

    2011-01-01

    Dam break can cause a significant disaster in the downstream,especially,in a valley with cascade reservoirs,which would aggravate the disaster extent.The experimental studies of the dam-break flow of cascade reservoirs are few and far between at the present.Most of related studies concern the failure of a single dam..This article presents an experimental study of the characteristics of an instantly filled dam-break flow of cascade reservoirs in a rectangular glass flume with a steep bottom slope.A new method was used to simulate the sudden collapse of the dam.A series of sensors for automatic water-levels were deployed to record the rapid water depth fluctuation.The experimental results show that,the ratio of the initial water depth of the downstream reservoir to that of the upstream reservoir would greatly affect the flood peak water depth in the downstream reservoir area and in the stream channel behind the downstream dam,while the influence of the dam spacing is insignificant.In addition,the comparison between the single reservoir and the cascade reservoirs shows some difference in the dam-break flow pattern and the stage hydrograph at the corresponding gauging points.

  20. Integrated Analysis of the Formation Mechanism of Cracks in a Concrete Dam Using Microseismic Monitoring and Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Gang He

    2016-01-01

    Full Text Available The dam of Guanyinyan hydropower station is composed of a concrete gravity dam in the left bank and a rockfill dam in the right bank. During the operation of the hydropower station, several surface cracks occurred in the concrete gravity dam, which threatened the stability of the dam. To evaluate the evolution trend of the cracks and forecast the potential risk of the dam, the microseismic (MS monitoring technique and finite-element method were used. First, the concrete three-point bending field test was performed to prove the reliability of the MS technique in monitoring the concrete cracks. The MS monitoring results were consistent with the simulation results. Then, the MS monitoring system was installed in the dam body. By analysing the MS activities before and after the impoundment, the evolution trend of the cracks and potential risk of the dam were evaluated and forecasted. The simulation results were also consistent with the monitoring results. These results can provide significant references for the operation safety of the dam and also present a new thought for the risk evaluation of similar dam engineering.

  1. EVALUASI KEAMANAN DAM JATILUHUR BERBASIS INDEKS RESIKO

    Directory of Open Access Journals (Sweden)

    Avazbek Ishbaev

    2014-12-01

    Full Text Available The dams have very important roles to agricultural activities. Especially, West Java with 240,000 hectares of agricultural land, needs a good dam structure that can be used sustainably. Jatiluhur dam in Purwakarta, West Java is one of big dams in Indonesia which has important rules not only for Purwakarta but also for Jakarta, Karawang and Bekasi residents. A study and observation about safety and dam stability is needed to prevent any damage. The purpose of this research were to identify parameters that influenced dam safety and to evaluate dam reliability based on index tools. Analysis was done using risk index tools. The result showed that the condition of the dam of Jatiluhur is still satisfied with indicators, "Idam"-750. The total index risk was 127.22 and the safety factor was 83.04 out of 100. Therefore, Jatiluhur dam could be classified as safe and no need for particular treatments. Jatiluhur dam can be operated in normal condition or abnormal condition with periodic monitoring. Keywords: dam safety, evaluation, Jatiluhur Dam, risk index tools

  2. Webinar: Stepped chute design for embankment dams

    Science.gov (United States)

    Changing demographics in the vicinity of dams have led to hazard creep in a number of dams worldwide. Many of these dams now have insufficient spillway capacity as a result of these changes in hazard classification from low to significant or high hazard. Stepped chutes applied to the embankment da...

  3. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The paper reports on the conclusions of decennial and annual inspections of French dams. Dams surveillance is performed by the operators and consists in visual examinations and measurements. Concrete dams, in particular, always have more or less developed fissures with water sweating threw the concrete mass or the foundations. Old concrete often show low swelling phenomena which are measured too. (J.S.)

  4. Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon-Interim Results

    Science.gov (United States)

    Buccola, Norman L.; Rounds, Stewart A.

    2011-01-01

    Prior to operational changes in 2007, Detroit Dam on the North Santiam River in western Oregon had a well-documented effect on downstream water temperature that was problematic for endangered salmonid fish species. In this U.S. Geological Survey study, done in cooperation with the U.S. Army Corps of Engineers, an existing calibrated CE-QUAL-W2 model of Detroit Lake (the impounded waterbody behind Detroit Dam) was used to determine how changes in dam operation or changes to the structural release points of Detroit Dam might affect downstream water temperatures under a range of historical hydrologic and meteorological conditions.

  5. Analysis of the behaviour of the Toulnoustouc CFRD Dam

    Energy Technology Data Exchange (ETDEWEB)

    Bouzaiene, H.; Chartrand, C. [RSW Inc., Montreal, PQ (Canada); Hammamji, Y. [Hydro-Quebec, Montreal, PQ (Canada)

    2006-07-01

    Concrete-face rockfill dams (CFRD) are typically designed using empirical methods which occasionally lead to leakage problems and the need for remedial measures. This paper argued that the application of numerical simulations in dam design may provide a greater understanding of CFRD dam behaviour. A 3D finite element method was used for the basic design of the Toulnustouc dam in Quebec. The interaction between the face concrete slabs, rockfill, and the rigid foundation was modelled with a specific emphasis on discontinuities of the concrete slabs. Data from a topographical survey was used to consider the rock excavation, dental concrete and the plinth alignment discontinuities. The rockfill modulus was calibrated using a 2D non-linear elastic model with plane deformation. Results of the modelling study were used to confirm the location of compression and tension joints for water stops design. The study showed that most of the joint sealing defects of CFRD dams were located at joints between slabs and at the plinth perimeter joint. Various analyses were then conducted to evaluate stress concentration in the reinforced concrete slabs and the variation of stresses with the rockfill deformation modulus as well as the contact points between the slab and the fill. It was observed that changes in plinth alignment introduced important tension stresses in the upstream face of the slabs within a band of 12 meters along the perimeter joint. Stresses were governed by the difference of rigidity of the fill and the developed friction forces between the fill and the slabs. It was concluded that the finite element model was useful in determining the behaviour of the CFRD dam. 3 refs., 15 figs.

  6. Environmental risk assessment of a dam during construction phase

    Directory of Open Access Journals (Sweden)

    S. Rezaian

    2016-12-01

    Full Text Available The present study was conducted to assess the possible risks induced by construction of Gavi Dam in Ilam Province; western part of Iran, using MIKE-11 model and technique for order of preference by similarity to ideal solution. For this purpose, vulnerable zone of the dam site against the flooding risk of Gavi River was calculated for different return periods. The flooding zones were stimulated by MIKE-11 model. In order to check whether or not the dam construction could affect the quality of the Gavi River, the physicochemical quality of the river water was also tested. Afterwards, a questionnaire was prepared containing an inventory of possible risks supposed to be induced by construction of Gavi Dam. The questionnaires were placed at disposal of experts to score the items based on their importance. The questionnaires were then analyzed using SPSS Software, version 16. According to which, a total number of 12 risk factors were identified. The dam construction risks were qualitatively assessed by preliminary hazard analysis. Based on the results, 3 of 12 identified risks were recognized unacceptable. The shortlisted risks were prioritized at final step using technique for order of preference by similarity to ideal solution. "Habitat fragmentation" with a weight of 0.3002, "water pollution" with a weight of 0.295, and "impacts on aquatics" with a weight of 0.293 were identified as three top priority flooding risks. Among the most important corrective measures for mitigation of the risks at construction phase can be pointed to "restoration of the land cover", “conservation of areas surrounding the dam as a new wildlife habitat", “prevention of water contamination”, and "conservation of fish spawning sites".

  7. The formation and failure of natural dams

    Science.gov (United States)

    Costa, J.E.; Schuster, R.L.

    1987-01-01

    Of the numerous kinds of dams that form by natural processes, dams formed from landslides, glacial ice, and neoglacial moraines present the greatest threat to people and property. The most common types of mass movements that form landslide dams are rock and debris avalanches, rock and soil slumps and slides, and mud, debris, and earth flows. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snowmelt and earthquakes. Landslide dams can be classified into six categories based on their relation with the valley floor. Type I dams (11%) of the 81 landslide dams around the world that were classifed do not reach from one valley side to the other. Type II dams (44%) span the entire valley flood, occasionally depositing material high up on opposite valley sides. Type III dams (41%) move considerable distances both upstream and downstream from the landslide failure. Type IV dams (1%) are rare and involve the contemporaneous failure of material from both sides of a valley. Type V dams (1%) are also rare, and are created when a single landslide sends multiple tongues of debris into a valley forming two or more landslide dams in the same surfaces, that extend under the stream or valley and emerge on the opposite valley side. Many landslide dams fail shortly after formation. Overtopping is by far the most common cause of failure. Glacial ice dams can produce at least nine kinds of ice-dammed lakes. The most dangerous are lakes formed in main valleys dammed by tributary glaciers. Failure can occur by erosion of a drainage tunnel under or through the ice dam or by a channel over the ice dam. Cold polar ice dams generally drain supraglacially or marginally by downmelting of an outlet channel. Warmer temperate-ice dams tend to fail by sudden englacial or subglacial breaching and drainage. Late neoglacial moraine-dammed lakes are located in steep mountain areas affected by the advances and retreats of valley glaciers in the last several

  8. Detrital Zircon Record of a Dammed River in Texas - Implications for Modern River Provenance Stories and Sediment Budgets

    Science.gov (United States)

    Dafov, L. N.; Stockli, D. F.; Mohrig, D. C.; Olariu, C.

    2016-12-01

    The Colorado River in Texas is a meandering river that is bisected by a chain of highland lakes and dams that were completed by 1951. Intuitively, dams trap sediment, but how does that disruption of sediment flow affect overall sediment flux and river morphology downstream of the dams? Observations from aerial photographs were combined with detrital zircon (DZ) U-Pb geochronology to quantify the anthropogenic effect of dams on sand generation. DZ U-Pb were collected from modern river channel sands, modern point bar sands, and modern delta sand sample. The U-Pb age data were evaluated in the context of bedrock U-Pb age data from the Llano Uplift Grenville basement above the dams and DZ U-Pb age data from the 30-40 km wide outcrop belt of Paleocene Wilcox Fm., dominated by Mesozoic Western US zircons, below the dams to evaluate possible entrenchment and sediment generation below the dams. While the modern river sediment collected upstream of the dams are dominated by Grenville DZ U-Pb ages, point bars below the dams show an abrupt increase of Wilcox derived zircons with only 1/3 of zircons derived from above the dams. This appears to be at least in part due to significant re-incision and erosion downstream of the dams out of the Paleocene Wilcox Formation. The lack of significant sand bars for 33 river kilometers below the dams and the progressive increase in sand bar size further downstream, combined with new DZ U-Pb data suggest that the modern river is incising into the Paleocene Wilcox below the dams and generating new sand. This is corroborated by the presence of 35 Ma DZ farther downstream, incorporated from Oligocene units. This progressive entrenchment of the river below the dams and incorporation of DZ from stratigraphic units encountered downstream illustrates the short-term response of the river geomorphology and sediment generation in light of anthropogenic perturbations of the river. These data also have interesting implications for sediment budget of

  9. Research on shape optimization of CSG dams

    Directory of Open Access Journals (Sweden)

    Xin CAI

    2011-12-01

    Full Text Available The multi-objective optimization method was used for shape optimization of cement sand and gravel (CSG dams in this study. The economic efficiency, the sensitivities of maximum horizontal displacement and maximum settlement of the dam to water level changes, the overall stability, and the overall strength security were taken into account during the optimization process. Three weight coefficient selection schemes were adopted to conduct shape optimization of a dam, and the case studies lead to the conclusion that both the upstream and downstream dam slope ratios for the optimal cross-section equal 1:0.7, which is consistent with the empirically observed range of 1:0.6 to 1:0.8 for the upstream and downstream dam slope ratios of CSG dams. Therefore, the present study is of certain reference value for designing CSG dams.

  10. Future directions of dam safety in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Verzeni, Gerard [Hydro Quebec, QC, (Canada)

    2010-07-01

    Gerard Verzeni, former director of the dam safety & environment at Hydro-Quebec introduced the future directions of dam safety in Canada. New and numerous challenges are emerging for the dam safety community. Measurable effects of climate changes illustrate that hydraulic forecasts would change drastically. Loads with times and amplitudes which are different from the actual knowledge will apply on dams. The development of new types of dams using recent technologies raises several issues, for example the longevity of such installations. The installations are becoming old and soon will require complete renovation and update for regulation and standards compliance. Concrete dams already need efforts and investment to maintain then in a safe state. Various factors will influence these challenges such as human resources in the dam safe community. In these conditions, it is important that organizations like CDA play an important role in providing support and reference and in being a driver for the whole industry.

  11. Study of Dam-break Due to Overtopping of Four Small Dams in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Zakaraya Alhasan

    2015-01-01

    Full Text Available Dam-break due to overtopping is one of the most common types of embankment dam failures. During the floods in August 2002 in the Czech Republic, several small dams collapsed due to overtopping. In this paper, an analysis of the dam break process at the Luh, Velký Bělčický, Melín, and Metelský dams breached during the 2002 flood is presented. Comprehensive identification and analysis of the dam shape, properties of dam material and failure scenarios were carried out after the flood event to assemble data for the calibration of a numerical dam break model. A simple one-dimensional mathematical model was proposed for use in dam breach simulation, and a computer code was compiled. The model was calibrated using the field data mentioned above. Comparison of the erodibility parameters gained from the model showed reasonable agreement with the results of other authors.

  12. Management of dams for the next Millennium: proceedings of the 1999 Canadian Dam Association

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    The meeting featured seven sessions with 18 papers abstracted/indexed therein as follows: keynote address: tailings dams safety - implications for the dam safety community; 1 - design and performance: performance monitoring of dams: are we doing what we should be doing?; tailings dams from the perspective of conventional dam engineering; and design overview of Syncrude's Mildred Lake east toe berm; 2 - design and modelling: use of a 2D model for a dam break study on the ALCAN hydroelectric complex in Quebec; and spillway design implications resulting from changes in rainfall extremes; 3 - risk and dam safety I: closing the gaps in the dam safety guidelines; the reality of life safety consequence classification; and surveillance practices for the next millenium; 4 - risk and dam safety II: quantitative risk-assessment using the capacity-demand analysis; and new guidelines for dam safety classification; 5 - millenium issues: expectations of immortality, dam safety management into the next millenium; 6 - rehabilitation techniques: the unconventional application of conventional materials; nondestructive testing technology to characterize concrete dam/bedrock interface; method and instrument for detecting crack in concrete; and grouting of the cracks in the Arch 5-6 - Daniel Johnson Dam; and 7 - case studies: rehabilitation of an 80 year old Ambursen type dam; and debris booms for the protection of spillways.

  13. Seismic stability safety evaluation of gravity dam with shear strength reduction method

    OpenAIRE

    Wang, Da-Sheng; Liao-jun ZHANG; Xu, Jian-Jun; Ming-jie HE; Wei-di ZHANG

    2009-01-01

    A new method of numerical seismic stability safety evaluation for a rock slope is proposed based on the analysis of a gravity dam foundation subjected to earthquake loading. The shear strengths of the weak discontinuities are divided by different shear strength reduction ratios (K) and numerical seismic analysis is carried out after the static analysis is completed. With different K values, the curves of the permanent horizontal displacement of key points of the dam foundation (K-displacement...

  14. Application of Probabilistic Method to Stability Analysis of Gravity Dam Foundation over Multiple Sliding Planes

    OpenAIRE

    Gang Wang; Zhenyue Ma

    2016-01-01

    The current challenge to the engineering profession is to carry out probabilistic methods in practice. The design point method in generalized random space (DPG method) associated with the method of divided difference can be utilized to deal with the complex problem of probability calculation of implicit performance function with nonnormal and correlated variables. For a practical concrete gravity dam, the suggested method is performed to calculate the instability probability of the dam founda...

  15. Brazil's Amazonian dams: Ecological and socioeconomic impacts

    Science.gov (United States)

    Fearnside, P. M.

    2016-12-01

    Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country's power. Losses in transmission lines (20%) are far above global averages and can be expected to increase as Amazonian hydroelectric dams far from consumer centers come on line. Brazil has tremendous wind and solar potential, but these do not have the same priority as dams. At the root of many questionable policies is a decision-making process in need of reform.

  16. Structure grid of the depth to the top of Pleistocene (Q99), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q99depth, ESRI binary grid, 400 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  17. Grid of the thickness of sediment above the Pleistocene surface Q30, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q30thick, ESRI binary grid, 200 m cell size, UTM, Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  18. Structure grid of the depth to the Pleistocene surface (Q30), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q30depth, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  19. Structure grid of the depth to the Pliocene surface (Q0), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q0depth,ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  20. Grid of the thickness of sediment above the Pleistocene surface Q30, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q30thick, ESRI binary grid, 200 m cell size, UTM, Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  1. Structure grid of the depth to the Pleistocene surface (Q50), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q50depth, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  2. Grid of the thickness of sediment above the Pleistocene surface Q50, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q50thick, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  3. Structure grid of the depth to the Pleistocene surface (Q30), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q30depth, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  4. Structure grid of the depth to the Pliocene surface (Q0), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q0depth,ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  5. Grid of the thickness of sediment above the Pleistocene surface Q50, inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q50thick, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  6. Structure grid of the depth to the top of Pleistocene (Q99), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q99depth, ESRI binary grid, 400 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  7. Structure grid of the depth to the Pleistocene surface (Q50), inner shelf and back-barrier from Virginia border to Cape Lookout, North Carolina (q50depth, ESRI binary grid, 200 m cell size, UTM Zone 18N, WGS 84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that...

  8. Analysis about the Influence of Clay Core Wall Structure towards the Slope Stability of High Embankment Dam

    Directory of Open Access Journals (Sweden)

    Li Bin

    2015-01-01

    Full Text Available As the main part of the anti-seepage system, core wall is a key point in the design of high em-bankment dam. The dam slope stability is a major factor for the type of core wall. But it is still unclear what effects the core wall structure might have on the slope stability. Based on practical projects of high embankment dam in Nuozhadu, Lianghekou and Shuangjiangkou, this paper analyzes safety factors and dangerous slip sur-faces of dam slopes of high embankment dams in both straight and slanting core wall structures and compares the influences of different core wall structures on the slope stability of high embankment dam through numerical calculations. The safety margin of the embankment dam of straight core wall is larger than that of slanting core wall in the operating condition of the reservoir water level’s drawdown. Compared with that of the straight core wall scheme, the position of the dangerous slip surface of the downstream dam slope is closer to the dam crest in the slanting core wall scheme.

  9. Dam breaking modeling on a river with ice cover : needs and tools : Hydro-Quebec perspective

    Energy Technology Data Exchange (ETDEWEB)

    Tchamen, G.W.; Quach, T.T.; Aubin, F.; Mellado, A. [Hydro-Quebec, Montreal, PQ (Canada). Unite Barrages and Hydraulique

    2007-07-01

    In order to ensure public safety, owners and operators of high capacity dams in Quebec have a legal obligation to conduct dam break analysis for each of their dams. Several scenarios of dam failure have been modelled under open water conditions to anticipate the worst-case scenario in terms of downstream consequences. However, the province of Quebec is located north of the 45th parallel, and most of the surface waters are ice covered in the winter. The presence of ice influences the river flow characteristics. As such, it is important to evaluate how ice may change the propagation of a surge wave and other important hydraulic parameters following a dam break. This paper reviewed traditional hydraulic methodologies and models used to perform dam break analyses with particular attention to the presence of ice. The changes in hydraulic processes in river flow involve various physical phenomena, some of which are poorly understood from a theoretical point of view. In the past several years, robust numerical techniques borrowed from fluid mechanics and aerodynamics have resulted in the development of robust hydrodynamic codes that effectively handle irregular bottom geometries, dry bed and mixed flow regimes in reasonable computational times. However, advances are still needed in the understanding of several ice processes, their formulation and their modeling. Data collection that would improve the understanding of the processes is also needed in order to reduce the level of uncertainties associated with the results of dam-break analysis. 22 refs., 3 tabs., 6 figs.

  10. The attitudes of dental interns to the use of the rubber dam at Riyadh dental colleges

    Directory of Open Access Journals (Sweden)

    Bander Mohammed Al-Abdulwahhab

    2012-01-01

    Full Text Available Background : The rubber dam is one of the best tools for tooth isolation and infection control in the dental field. Our aim is to evaluate the attitudes toward the use of rubber dams by dental interns in Riyadh Dental Colleges (RCsDP and determine the barriers to their use. Materials and Methods: A self-administered questionnaire was designed and used for data collection. 150 questionnaires were distributed by hand to the dental interns of RCsDP over a period of two weeks. Information sought included the attitudes toward and difficulties for the use of the rubber dam, the time needed to apply the rubber dam, and the patients′ allergic history of the rubber dam. Respondents were asked to state their preference on a five point Likert type scale ranging from "strongly dislike" to "strongly like". The information and data of the completed questionnaires were statistically analyzed using Mann-Whitney U test and Friedman test. Results: Of 150 questionnaires distributed, 150 were completed and returned (response rate = 100%. Of those, 46.7% were males and 53.3% were females. In general; (43.3%, interns strongly liked the use of the rubber dam and the rest (46.7% liked the use of the rubber dam. The majority of respondents liked to use rubber dam in direct restorations more than in indirect restorations and 46.7% strongly liked to use it in posterior teeth for composite restoration. Most dental interns felt that they would strongly like to use a rubber dam for endodontic treatment whether in posterior teeth (73.3% or anterior teeth (68.7%. 66.7% of interns asked their patients if they had an allergy to latex prior to the use of the rubber dam. Child behavior (mean rank about seven is the most important reason for not using rubber dam. The time is taken to apply the rubber dam was less than five minutes in most cases. Conclusion: Most dental interns prefer to use rubber dams in the general dental field and are enthusiastic to use it in future.

  11. Exporting dams: China's hydropower industry goes global.

    Science.gov (United States)

    McDonald, Kristen; Bosshard, Peter; Brewer, Nicole

    2009-07-01

    In line with China's "going out" strategy, China's dam industry has in recent years significantly expanded its involvement in overseas markets. The Chinese Export-Import Bank and other Chinese financial institutions, state-owned enterprises, and private firms are now involved in at least 93 major dam projects overseas. The Chinese government sees the new global role played by China's dam industry as a "win-win" situation for China and host countries involved. But evidence from project sites such as the Merowe Dam in Sudan demonstrates that these dams have unrecognized social and environmental costs for host communities. Chinese dam builders have yet to adopt internationally accepted social and environmental standards for large infrastructure development that can assure these costs are adequately taken into account. But the Chinese government is becoming increasingly aware of the challenge and the necessity of promoting environmentally and socially sound investments overseas.

  12. Dam safety review, classification of dams for the Novia Scotia Power Inc. Black River hydroelectric system

    Energy Technology Data Exchange (ETDEWEB)

    Alderman, Aaron; Small, Andy [AMEC Earth and environmental, Fredericton, (Canada); O' Neil, Ellis [Nova Scotia Power Inc., Halifax, (Canada)

    2010-07-01

    In 2009, AMEC was retained by Nova Scotia Power Inc. (NSPI) to conduct a dam safety review of the dams that are part of the Black River Hydroelectric System. This paper presented the results of this dam classification exercise which was carried out for the Bear River hydroelectric system in Nova Scotia, based on the 2007 Canadian Dam Association (CDA) dam safety guidelines. Flood mapping and dam-break analysis were performed for events ranging from the 1:100 year to PMF flood events, including cascading events. These results were used to draw up a classification of the dams. Associated design criteria were then developed. Following the assessment of the dam sites, conclusions and recommendations were discussed. The recommendations were presented in terms of regular maintenance items and reconstruction items, which are now used by NSPI to determine the party responsible for undertaking the recommendation and for evaluation of the maintenance and reconstruction schedules.

  13. Dam Inventory, dams, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Dam Inventory dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'dams'. Data...

  14. Study on dynamic anti-sliding stability of a high gravity dam considering complex dam foundation

    OpenAIRE

    Deng-hong CHEN; Cheng-bin DU

    2011-01-01

    There existed some limitations when analyzing the anti-sliding seismic stability of dam-foundation system by traditional pseudo-static method and response spectrum method. The dynamic strength reduction method was used to study on the deep anti-sliding stability of a high gravity dam considering complex dam foundation under strong earthquake-induced ground action. The static analysis was firstly carried out by reducing the shear strength parameters of the dam foundation’s rock mass with equal...

  15. 78 FR 60271 - Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of Application for Transfer of...

    Science.gov (United States)

    2013-10-01

    ... Federal Energy Regulatory Commission Hollow Dam Power Company; Ampersand Hollow Dam Hydro, LLC; Notice of..., Hollow Dam Power Company (transferor) and Ampersand Hollow Dam Hydro, LLC (transferee) filed an application for transfer of license for the Hollow Dam Project, FERC No. 6972, located on the West Branch...

  16. Numerical modelling for stability of tailings dams

    OpenAIRE

    Auchar, Muhammad; Mattsson, Hans; Knutsson, Sven

    2013-01-01

    A tailings dam is a large embankment structure that is constructed to store the waste from the mining industry. Stability problems may occur in a tailings dam due to factors such as quick rate of raising, internal erosion and liquefaction. The failure of a tailings dam may cause loss of human life and environmental degradation. Tailings Dams must not only be stable during the time the tailings storage facility is in operation, but also long time after the mine is closed. In Sweden, the licens...

  17. Debris Flow Dam Formation in Southeast Tibet

    Institute of Scientific and Technical Information of China (English)

    CHENG Zunlan; WU Jishan; GENG Xueyong

    2005-01-01

    Glaciers with their deposits abound in the alpine areas of Southeast Tibet. Large debris flows occur frequently from these deposits and form dams that block streams. In this paper, 3 events of large debris flows reported in Peilong Valley located in Southeast Tibet, and which resulted 2 blocking dams resulted, are discussed in details, focusing on the major factors controlling dam formation. The results shows that the first surge group caused by snow and ice avalanches, ice-lake breaks, and large-scale landslides, with a high peak discharge and high velocity, and an abundance of boulders, are most likely to form blocking dams.

  18. Comprehensive evaluation methods for dam service status

    Institute of Scientific and Technical Information of China (English)

    WU ZhongRu; XU Bo; GU ChongShi; LI ZhanChao

    2012-01-01

    More than 87000 dams have been built in China,and about one third of them are risky projects.A number of high and ultra-high dams are being constructed in China's western region.The current dam construction practice tends to focus on socio-economic benefits and neglect the environment and ecology.Furthermore,periodic examinations are intended to ensure the structural safety of dams.This paper proposes a general evaluation principle for dam service.This principle stipulates that dam projects should have maximum socio-economic benefits and minimum negative effects on the environment and ecology.To satisfy the general principle of mutual harmony,socio-economic benefits,dam safety,environment,and ecology are analyzed,and the evaluation methods for dam service status are discussed.Then,a fusion algorithm of interlayer assessment is proposed on the basis of evidence theory and the fuzzy comprehensive analysis method.Finally,a comprehensive evaluation model is established.Example analysis shows that the proposed theories and methods can fulfill scientific assessment of the service status of dams.

  19. Geophysical investigation of earth dam using the electrical tomography resistivity technique

    Directory of Open Access Journals (Sweden)

    Pedro Lemos Camarero

    Full Text Available Abstract Dams are structures that dam rivers and streams for a variety of purposes. These structures often need to be sturdy to withstand the force of the impoundment and the high values of accumulated water load. The constant maintenance of these structures is essential, since a possible accident can lead to damage of catastrophic proportions. This research presents an alternative cheap and quick application for investigating water seepage in earth dams, through the application of the DC resistivity geophysical method from the electrical resistivity tomography (ERT technique in Wenner array. Three ERT lines were placed parallel to the longitudinal axis of a dam formed by clay soil from the decomposition of diabase. The data are presented in 2D and pseudo-3D geophysical images with electrical resistivity values modeled. Based on the physical principle of electrolytic conduction, that is, decrease in electrical resistance in materials or siliceous minerals in moisture conditions as compared to the material in the dry state, the results revealed low-resistivity zones restricted to some points, associated with water infiltration in the transverse direction of the dam. The absence of evidence as water upwelling on the front of the dam together with geophysical evidence indicate saturation restricted to some points and low probability at the present time, for installation of piping processes.

  20. Safety Aspects of Sustainable Storage Dams and Earthquake Safety of Existing Dams

    Directory of Open Access Journals (Sweden)

    Martin Wieland

    2016-09-01

    Full Text Available The basic element in any sustainable dam project is safety, which includes the following safety elements: ① structural safety, ② dam safety monitoring, ③ operational safety and maintenance, and ④ emergency planning. Long-term safety primarily includes the analysis of all hazards affecting the project; that is, hazards from the natural environment, hazards from the man-made environment, and project-specific and site-specific hazards. The special features of the seismic safety of dams are discussed. Large dams were the first structures to be systematically designed against earthquakes, starting in the 1930s. However, the seismic safety of older dams is unknown, as most were designed using seismic design criteria and methods of dynamic analysis that are considered obsolete today. Therefore, we need to reevaluate the seismic safety of existing dams based on current state-of-the-art practices and rehabilitate deficient dams. For large dams, a site-specific seismic hazard analysis is usually recommended. Today, large dams and the safety-relevant elements used for controlling the reservoir after a strong earthquake must be able to withstand the ground motions of a safety evaluation earthquake. The ground motion parameters can be determined either by a probabilistic or a deterministic seismic hazard analysis. During strong earthquakes, inelastic deformations may occur in a dam; therefore, the seismic analysis has to be carried out in the time domain. Furthermore, earthquakes create multiple seismic hazards for dams such as ground shaking, fault movements, mass movements, and others. The ground motions needed by the dam engineer are not real earthquake ground motions but models of the ground motion, which allow the safe design of dams. It must also be kept in mind that dam safety evaluations must be carried out several times during the long life of large storage dams. These features are discussed in this paper.

  1. Mechanical effects of excavation rebound of arch dam bedrock and better concreting time of dam body

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In high ground stress zone, rebound deformation of excavation of arch dam bedrock has a significant impact on the structural behavior, design and construction of arch dam. Based on the analysis of mechanical effects of excavation rebound, with both stress and deformation as two constraint conditions and deformation modulus as a controlling condition, the method to determine a better concreting time of dam body was put forward. All of these play an important guiding role in the excavation of dam bedrock and the construction of dam body.

  2. McNary Dam, Ice Harbor Dam, and Lower Monumental Dam Smolt Monitoring Program; 1996 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hillson, Todd; Lind, Sharon; Price, William (Washington Department of Fish and Wildlife, Olympia, WA)

    1997-07-01

    The Washington Department of Fish & Wildlife (WDFW) assumed responsibility for the Smolt Monitoring Program at McNary Dam on the Columbia River in 1990 and at the new juvenile collection facility at Lower Monumental Dam on the Snake River in 1993. In 1996, Smolt Monitoring Program activities also began at the new juvenile collection facility located at Ice Harbor Dam. This report summarizes the 1996 Smolt Monitoring work at all three sites. The work at Ice Harbor consisted of Gas Bubble Trauma (GBT) monitoring only. In general, the 1996 passage season at both the McNary and Lower Monumental sites can be characterized by reduced passage of juveniles through the collection systems due to elevated river flows and spill, and low (<1%) overall facility mortality rates most likely resulting from cooler water temperatures. In accordance with the National Marine Fisheries Service recommendations (NMFS, 1995) all spring migrants were bypassed at McNary Dam in 1996. Mechanical problems within the McNary collection system resulted in collection and sampling activities being delayed until April 18 at this site, while sampling and collection began on the scheduled starting date of April 1 at Lower Monumental Dam. Monitoring operations were conducted through December 14 at McNary Dam and through October 28 at Lower Monumental Dam. An ongoing transportation evaluation summer migrant marking program was conducted at McNary Dam in 1996 by the NMFS. This necessitated the sampling of 394,211 additional fish beyond the recommended sampling guidelines. All total, 509,237 and 31,219 juvenile salmonids were anesthetized and individually counted, examined for scale loss, injuries, and brands by WDFW Smolt Monitoring personnel in 1996 at McNary Dam and Lower Monumental Dam, respectively.

  3. Adaptability to geological faulted foundation of Hardfill dam

    Institute of Scientific and Technical Information of China (English)

    Kun XIONG; Yunlong HE; Yunfeng PENG

    2008-01-01

    Hardfill dam is a new type of dam which has the advantages of low stress level and even stress distri-bution in a dam body, resulting in low demands to foun-dations. Based on 2D linear elastic and elasto-plastic calculations of gravity dam and Hardfill dam using finite element method (FEM), the stress distribution in a dam body and anti-sliding stabilization is analyzed on the geo-logical faulted foundations with weak weathered rock and soft interlayers. It is concluded that Hardfill dams have better adaptability to geological faulted foundations than gravity dams and is more secure and economically sound.

  4. Vulnerability of aged concrete gravity dams

    Energy Technology Data Exchange (ETDEWEB)

    Gogoi, I. [Assam Engineering Institute, Guwahati (India). Dept. of Civil Engineering; Maity, D. [Indian Institute of Technology, Guwahati (India). Dept. of Civil Engineering

    2004-07-01

    This paper presented an analysis procedure to predict the effects of aging on the behavior of concrete gravity dams. A time dependent isotropic damage index was determined, presenting the performance of the dam with increasing age. Results revealed that the degradation process is dependent on the design life of the structure. The influence of damage along the dam height was greater than damage observed along its width. In order to consider the time dependent degradation of concrete owing to environmental factors and mechanical loading, an algorithm was presented in order to forecast the behavior of existing dams and to assess the necessity of retrofitting or decommissioning. It was concluded that dam behavior during seismic excitation is influenced by the effects of both the dam reservoir system and initial earthquake damage. With increasing age, dam displacement increases, but hydrodynamic pressures and stresses exerted by reservoirs decrease. It was recommended that more accurate behavior could be determined if further research into the coupled effect of foundation-dam-reservoir interaction with material non-linearity was considered. 15 refs.,15 figs.

  5. Upgrading of Boundary Dam spillway

    Energy Technology Data Exchange (ETDEWEB)

    McPhail, Gordon; MacMillan, Dave; Smith, Bert [KGS Group, Winnipeg, (Canada); Lacelle, Justin [SaskPower, Regina, (Canada)

    2010-07-01

    An initial dam safety review was performed in 2005 and identified a number of concerns; the most critical were insufficient spillway capacity and deficiencies in the condition of the existing spillways. This paper described the challenges faced by the upgrading operation on the 50 year old Boundary Dam spillway started in 2008. SaskPower retained the KGS Group to increase the design spillway capacity to 1200 m3/s and remedy observed defects. The construction project involved maintaining the reservoir at full supply level while the 20m long spillway chute and stilling basin below were completely replaced. The difficulties came from the need to complete each year's construction such that the spillway could potentially pass spring flood flows. This paper showed that the upgrade measures selected for implementation were developed through close dialogue between the owner and the designer, with valuable input provided by a panel of external experts as well as from contractors participating in the design process.

  6. Restoring Environmental Flows by Modifying Dam Operations

    Directory of Open Access Journals (Sweden)

    Gregory A. Thomas

    2007-06-01

    Full Text Available The construction of new dams has become one of the most controversial issues in global efforts to alleviate poverty, improve human health, and strengthen regional economies. Unfortunately, this controversy has overshadowed the tremendous opportunity that exists for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. This paper describes an assessment framework that can be used to evaluate the benefits that might be restored through dam re-operation. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. The paper highlights a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the

  7. Research progress on dam-break floods

    KAUST Repository

    Wu, Jiansong

    2011-08-01

    Because of the catastrophic effects downstream of dam-break failure, more and more researchers around the world have been working on the study of dam-break flows to accurately forecast the downstream inundation mapping. With the rapid development of computer hardware and computing techniques, numerical study on dam-break flows has been a popular research subject. In the paper, the numerical methodologies used to solve the governing partial differential equations of dam-break flows are classified and summarized, and their characteristics and applications are discussed respectively. Furthermore, the fully-developed mathematical models developed in recent decades are reviewed, and also introduced the authors\\' on-going work. Finally, some possible future developments on modeling the dam-break flows and some solutions are presented and discussed. © 2011 IEEE.

  8. Do we need construct more dams?

    Science.gov (United States)

    Chen, J.; Shi, H.

    2013-12-01

    This paper reviews global dam development in association with the growths of global population, economy, and energy consumption in the past several decades, and also evaluates contributions of dam development to future world sustainable development. Eventually, this paper answers whether we need more dams in the future or not. The world population has rapidly increased from 1.6 billion in 1900, 2.5 billion in 1950, 6.1 billion in 2000, to 7.0 billion in 2011, and is projected to reach 9.5 billion in 2050; similarly, the world economy has dramatically expanded. To maintain socioeconomic development, the consumption of water, food and energy has increased rapidly as well. However, the total volume of available water resource over the world is limited, the food production largely depends on water supply, and the main energy sources are still oil, coal and gas at present, which are regarded as non-renewable resources. Accordingly, it is expected that we will face serious problems to deal with the challenges of water crisis, food security and energy shortage in the near future. In order to enhance the capability of regulating water resource, a great number of global dams (and related reservoirs) have been constructed in the last one hundred years; currently, almost all large rivers over the world have been regulated by dams. The reservoirs can supply sufficient water for irrigated land to ensure food production, and the associated hydropower stations can generate electricity. This article collects the dam data from the ICOLD (International Commission on Large Dams) and GRanD (Global Reservoir and Dam) databases, and some socioeconomic data, including population, economy, and consumptions of water, food and energy over the world. Analysis of these data reveals that global dam development has a great impact on the world sustainable development. Further, it is concluded that we need further dam development to maintain our future development.

  9. Check dams effects on sediment transport in steep slope flume

    Science.gov (United States)

    Piton, Guillaume; Recking, Alain

    2014-05-01

    Depending on many influences (geology, relief, hydrology, land use, etc.) some mountainous watershed are prone to cause casualties and facilities damages. Large amounts of sediments episodically released by torrents are often the biggest problem in torrent related hazard mitigation. Series of transversal structures as check dams and ground sills are often used in the panel of risk mitigation technics. A large literature exits on check dams and it mainly concerns engineering design, e.g. toe scouring, stability stress diagram, changes in upper and lower reaches equilibrium slopes. Check dams in steep slope rivers constitute fixed points in the bed profile and prevent general bed incision. However their influence on sediment transport once they are filled is not yet clear. Two flume test campaigns, synthetize in Table 1, were performed to investigate this question: Table 1 : experiment plan Run (duration) Ref1 (50h)CD1a (30h)CD1b (30h)Ref2 (92h)CD2 (18h) Solid feeding discharge (g.s^-1) 44 44 44 60 60 Number of check dams none 1 3 none 2 A nearly 5-m-long, 10-cm-wide and 12%-steep flume was used. The water discharge was set to 0,55 l/s in all runs. A mixture of poorly sorted natural sediments with diameters between 0.8 and 40 mm was used. An open solid-discharge-feeding circuit kept the inlet sediment flux constant during all experiments. As both feeding rates did not present variation, changes in outlet solid discharge were assumed to be due to bed variations in the bed storage. We observed strong fluctuations of solid flux and slope in each reaches of all runs between: (i) steep aggradating armoured bed and (ii) less steep and finer bed releasing bedload sheets during erosion events and inducing bedload pulses. All experiments showed consistent results: transported volume associated with erosion event decreased with the length between two subsequent check dams. Solid transversal structures shorten the upstream erosion-propagation and avoid downstream change in the

  10. Seismic failure modes and seismic safety of Hardfill dam

    Institute of Scientific and Technical Information of China (English)

    Kun XIONG; Yong-hong WENG; Yun-long HE

    2013-01-01

    Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

  11. After Three Gorges Dam: What have we learned?

    Science.gov (United States)

    Natali, J.; Williams, P.; Wong, R.; Kondolf, G. M.

    2013-12-01

    China is at a critical point in its development path. By investing heavily in large-scale infrastructure, the rewards of economic growth weigh against long-term environmental and social costs. The construction of Three Gorges Dam, the world's largest hydroelectric project, began in 1994. Between 2002 and 2010, its 660 kilometer reservoir filled behind a 181 meter dam, displacing at least 1.4 million people and transforming Asia's longest river (the Yangtze) while generating nearly 100 billion kWh/yr of electricity -- 2.85% of China's current electric power usage. As the mega-project progenitor in a cascade of planned dams, the Three Gorges Dam emerges as a test case for how China will plan, execute and mitigate its development pathway and the transformation of its environment. Post-Project Assessments (PPA) provide a systematic, scientific method for improving the practice of environmental management - particularly as they apply to human intervention in river systems. In 2012, the Department of Landscape Architecture and Environmental Planning at University of California, Berkeley organized a symposium-based PPA for the Three Gorges Dam on the Yangtze River. Prior to this symposium, the twelve invited Chinese scientists, engineers and economists with recent research on Three Gorges Dam had not had the opportunity to present their evaluations together in an open, public forum. With a 50-year planning horizon, the symposium's five sessions centered on impacts on flows, geomorphology, geologic hazards, the environment and socioeconomic effects. Three Gorges' project goals focused on flood control, hydropower and improved navigation. According to expert research, major changes in sediment budget and flow regime from reservoir operation have significantly reduced sediment discharge into the downstream river and estuary, initiating a series of geomorphic changes with ecological and social impacts. While the dam reduces high flow stages from floods originating above the

  12. Removal of the dam sediments as a way of control of eutrophication. Eliminacion de los sedimentos en los embalses como medida de control de la eutrofizacion

    Energy Technology Data Exchange (ETDEWEB)

    Lacalle Pareja, B.; Gonzalez Garcia, P.; Pino Izquierdo, M.I.; Gomez Artola, C.

    1994-01-01

    It is raised the advantage of thinking over the utility of removing the dam sediments as a way of control of eutrophication, attending to the distribution and concentration in different points of bottom on three dams of the Community of Madrid destined to the human consume. Attending to the sediments dynamic and the geomorphological and climatic characteristics. (Author) 6 refs.

  13. EVALUATION OF THE WATER TROPHIC STATE OF WAPIENICA DAM RESERVOIR

    Directory of Open Access Journals (Sweden)

    Ewa Jachniak

    2015-01-01

    Full Text Available In this publication the trophy level of Wapienica dam reservoir, based on the composition species of planktonic algae and their biomass, and concentrations of chlorophyll a, was defined. The research was conducted during the vegetative season in 2013 year; the samples were taken from two research points (W1 – the part of river Wapienica inflow to reservoir and W2 – the part of the reservoir dam by using bathometer. The whole biomass of planktonic algae and concentration of chlorophyll a from two research areas were low and it allowed to classify water of this reservoir to oligo-/ mesotrophic. Only in the part of the reservoir dam, in summer season, an increased trophy level was observed (Heinonen 1980. A similar trophic character (oligo-/ mesotrophic of the water reservoir was also indicated by algae species: Achnanthes lanceolata (Bréb. Grun. in Cl. and Grun., Chrysoccoccus minutus (Fritsch Nygaard. For a temporary increase of the trophy level, the diatom Nitzschia acicularis (Kütz. W. Sm. could indicate, because it is a typical species in poorly eutrophic water. The green algae (Pediastrum and Coelastrum, which were observed in summer season could also indicate for a rise of the trophic state, because they are typical for eutrophic water.

  14. The requirement for the Dam1 complex is dependent upon the number of kinetochore proteins and microtubules.

    Science.gov (United States)

    Burrack, Laura S; Applen, Shelly E; Berman, Judith

    2011-05-24

    The Dam1 complex attaches the kinetochore to spindle microtubules and is a processivity factor in vitro. In Saccharomyces cerevisiae, which has point centromeres that attach to a single microtubule, deletion of any Dam1 complex member results in chromosome segregation failures and cell death. In Schizosaccharomyces pombe, which has epigenetically defined regional centromeres that each attach to 3-5 kinetochore microtubules, Dam1 complex homologs are not essential. To determine why the complex is essential in some organisms and not in others, we used Candida albicans, a multimorphic yeast with regional centromeres that attach to a single microtubule. Interestingly, the Dam1 complex was essential in C. albicans, suggesting that the number of microtubules per centromere is critical for its requirement. Importantly, by increasing CENP-A expression levels, more kinetochore proteins and microtubules were recruited to the centromeres, which remained fully functional. Furthermore, Dam1 complex members became less crucial for growth in cells with extra kinetochore proteins and microtubules. Thus, the requirement for the Dam1 complex is not due to the DNA-specific nature of point centromeres. Rather, the Dam1 complex is less critical when chromosomes have multiple kinetochore complexes and microtubules per centromere, implying that it functions as a processivity factor in vivo as well as in vitro.

  15. Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

    Science.gov (United States)

    Sokolow, Susanne H.; Jones, Isabel J.; Jocque, Merlijn M. T.; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L.; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M.; De Leo, Giulio A.

    2017-01-01

    Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.

  16. Fungi as Architects of the Rimstone Dams in Huanglong, NSD, Sichuan, China.

    Science.gov (United States)

    Xie, Jie; Strobel, Gary; Xu, Wei-Fang; Chen, Jie; Ren, Hui-Shuang; An, De-Jun; Geary, Brad

    2017-01-01

    The Huanglong park area of the Sichuan Province of China is a unique scenic area of the world. It is known for its thousands of aquamarine-colored pools that are formed behind naturally formed rimstone dams of travertine (calcite) along a cold water stream. The travertine, based on its crystalline structural analysis, is of biological origin. This makes sense since the temperature of the waters of Huanglong varies from 5 to 7 °C and thus geochemical crystallization does not occur as it does in other locations around the world possessing thermal pools whose structures are primarily formed through cooling processes. Fungi and bacteria were discovered associated with both leaves associated with the calcite dams as well as in the older parts of well-established dams. Several species of Phytium, a phycomycete and an endophyte, accounted for over 45 % of all of the fungi successfully isolated from the well-established dam samples and at least 85 % in the floating leaf samples. Saprolegnia spp. (Phycomycetes) along with Phoma spp. (Ascomycetes) were noted along with Mortierella sp. as other dam-associated fungi. The fungal hyphae observed on dead leaf material as well as in the calcite dams directly served as nucleation points for the formation of crystalline CaCO3. Eventually, these crystals grow large enough to fuse to make calcite plates which form the main structural feature of all of the travertine dams in this area. Interestingly, each of the individual crystals associated with the dams has an associated hole in its core where a fungal hypha used to reside as observed by scanning electron microscopy. While diatoms were present in the analysis, they too seem to contribute to the structure of the dams but in a minor way. The only bacteria isolated from the older dam of this aquatic environment were Pseudomonas spp. and their role in dam formation is uncertain. Huanglong is a unique and beautiful place, and the water features present in this area can definitely be

  17. Epigenetic Influence of Dam Methylation on Gene Expression and Attachment in Uropathogenic Escherichia coli.

    Science.gov (United States)

    Stephenson, Stacy Ann-Marie; Brown, Paul D

    2016-01-01

    Urinary tract infections (UTI) are among the most frequently encountered infections in clinical practice globally. Predominantly a burden among female adults and infants, UTIs primarily caused by uropathogenic Escherichia coli (UPEC) results in high morbidity and fiscal health strains. During pathogenesis, colonization of the urinary tract via fimbrial adhesion to mucosal cells is the most critical point in infection and has been linked to DNA methylation. Furthermore, with continuous exposure to antibiotics as the standard therapeutic strategy, UPEC has evolved to become highly adaptable in circumventing the effect of antimicrobial agents and host defenses. Hence, the need for alternative treatment strategies arises. Since differential DNA methylation is observed as a critical precursor to virulence in various pathogenic bacteria, this body of work sought to assess the influence of the DNA adenine methylase (dam) gene on gene expression and cellular adhesion in UPEC and its potential as a therapeutic target. To monitor the influence of dam on attachment and FQ resistance, selected UPEC dam mutants created via one-step allelic exchange were transformed with cloned qnrA and dam complement plasmid for comparative analysis of growth rate, antimicrobial susceptibility, biofilm formation, gene expression, and mammalian cell attachment. The absence of DNA methylation among dam mutants was apparent. Varying deficiencies in cell growth, antimicrobial resistance and biofilm formation, alongside low-level increases in gene expression (recA and papI), and adherence to HEK-293 and HTB-9 mammalian cells were also detected as a factor of SOS induction to result in increased mutability. Phenotypic characteristics of parental strains were restored in dam complement strains. Dam's vital role in DNA methylation and gene expression in local UPEC isolates was confirmed. Similarly to dam-deficient Enterohemorrhagic E. coli (EHEC), these findings suggest unsuccessful therapeutic use of

  18. Augmented reality graphic interface for upstream dam inspection

    Science.gov (United States)

    Cote, Jean; Lavallee, Jean

    1995-12-01

    This paper presents a 3D graphic interface for the inspection of cracks along a dam. The monitoring of concrete dams is restricted by the accessibility of the various parts of the structure. Since the upstream face of a dam is not usually exposed, as in our case at Hydro- Quebec, a systematic and even ad hoc inspection become extremely complex. The piloting of a ROV (Remotely Operated Vehicle) underwater is like driving in a snowstorm. The view from the camera is similar to the visibility a driver would have in a snowstorm. Sensor fusion has to be performed by the operator since each sensor is specialized for its task. Even with a 2D positioning system or sonar scan, the approach to the inspection area is very tedious. A new 3D interface has been developed using augmented reality since the position and orientation of the vehicle are known. The point of view of the observer can easily be changed during a manipulation of the ROV. A shared memory based server can access the position data of the ROV and update the graphics in real time. The graphic environment can be used as well to drive the ROV with computer generated trajectories. A video card will be added to the Silicon Graphics workstation to display the view of the camera fixed to the ROV. This visual feedback will only be available when the ROV is close enough to the dam. The images will be calibrated since the position of the camera is known. The operator interface also includes a set of stereoscopic camera, hydrophonic (sound) feedback and imaging tools for measuring cracks.

  19. TYPOLOGY OF LARGE DAMS. A REVIEW

    Directory of Open Access Journals (Sweden)

    Gheorghe ROMANESCU

    2015-06-01

    Full Text Available The dams represent hydrotechnical constructions meant to ensure a judicious use of water resources. The international literature is extremely rich in data regarding the large dams on Earth. In this context, a hierarchy of the main dams is attempted and the role they play in the economic development of the regions they were built in is underlined. The largest dams are built on the big rivers in Asia, North America, South America and Africa. The reservoirs have multiple roles: electricity production, drinking or industrial water supply, irrigations, recreation, etc. High costs and land fragility do not allow the construction of dams in the places most affected by drought or flood. This is why they are usually built in mountainous areas, at great distance from the populated centres. On the Romanian territory, there are 246 large dams, built in the hydrographical basins of Siret, Olt, Arges, Somes, etc. The largest rivers on Earth, by discharge, (Amazon and Zair do not also include the largest dams because the landform and the type of flow have not allowed such constructions.

  20. Ririe Dam Release Test Assessment

    Science.gov (United States)

    2013-06-01

    72 Lyme Road Hanover, NH 03755-1290 Stephen Hall and Jeremy Giovando US Army Engineer District, Walla Walla 201 North Third Avenue Walla Walla...11/2013 at 0330 2/12/2013 at 1410 10120114 95th St. (1) 10120115 55th St. (2) 2/11/2013 at 1010 2/12/2013 at 2120 10120111 55th St. (1) 9737377...Ririe Dam 2/10/2013 at 1440 0 hr 64,700 N 95th E 2/12/2013 at 1410 47 hr 30 min 0.32 0.32 33,020 55th St. Bridge 2/12/2013 at 2120 54 hr 40 min

  1. The geomorphic legacy of small dams — An Austrian study

    NARCIS (Netherlands)

    Poeppl, R.E.; Keesstra, S.D.; Hein, T.

    2015-01-01

    Dams represent one of the most dominant forms of human impact upon fluvial systems during the Anthropocene, as they disrupt the downstream transfer of water and sediments. Removing dams restores river continuity and channel morphology. Both dam construction and dam removal induce geomorphic channel

  2. Mechanical analysis of a gravity dam

    OpenAIRE

    Bergant, Urša

    2012-01-01

    In the first part of our work we will present the water supply project in Obala and backend Karst regions. The use of the river Reka and its tributary Suhorka is essential, since an amassment is going to be built on it. We decided to build the dam from rolled concrete, which is economically and environmentally better than a paved barrier or a classic concrete dam. The second part of our work includes tension and stability program calculations. The primary dimensions of the dam-taken from a te...

  3. Sustainability of dams-an evaluation approach

    Science.gov (United States)

    Petersson, E.

    2003-04-01

    Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the

  4. Geophysics Methods in Electrometric Assessment of Dams

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, V. A., E-mail: davydov-va@yandex.ru; Baidikov, S. V., E-mail: badikek@mail.ru; Gorshkov, V. Yu., E-mail: vitalaa@yandex.ru; Malikov, A. V., E-mail: alex.mal.1986@mail.ru [Russian Academy of Sciences, Geophysical Institute, Ural Branch (Russian Federation)

    2016-07-15

    The safety assessment of hydraulic structures is proposed to be conducted via geoelectric measurements, which are capable of assessing the health of earth dams in their natural bedding without intervention in their structure. Geoelectric measurements are shown as being capable of pinpointing hazardous parts of a dam, including areas of elevated seepage. Applications of such methods are shown for a number of mini-dams in the Sverdlovsk region. Aparameter (effective longitudinal conductivity) that may be used to monitor the safety of hydraulic structures is proposed. Quantitative estimates of this parameter are given in terms of the degree of safely.

  5. Thorium isotopes in colloidal fraction of water from San Marcos Dam, Chihuahua, Mexico

    Science.gov (United States)

    Cabral-Lares, M.; Melgoza, A.; Montero-Cabrera, M. E.; Renteria-Villalobos, M.

    2013-07-01

    The main interest of this stiidy is to assess the contents and distribution of Th-series isotopes in colloidal fraction of surface water from San Marcos dam, because the suspended particulate matter serves as transport medium for several pollutants. The aim of this work was to assess the distribution of thorium isotopes (232Th and 230Th) contained in suspended matter. Samples were taken from three surface points along the San Marcos dam: water input, midpoint, and near to dam wall. In this last point, a depth sampling was also carried out. Here, three depth points were taken at 0.4, 8 and 15 meters. To evaluate the thorium behavior in surface water, from every water sample the colloidal fraction was separated, between 1 and 0.1 μm. Thorium isotopes concentraron in samples were obtained by alpha spectrometry. Activity concentrations obtained of 232Th and 230Th in surface points ranged from 0.3 to 0.5 Bq ṡ L-1, whereas in depth points ranged from 0.4 to 3.2 Bq ṡ L-1, respectively. The results show that 230Th is in higher concentration than 232Th in colloidal fraction. This can be attributed to a preference of these colloids to adsorb uranium. Thus, the activity ratio 230Th/232Th in colloidal fraction showed values from 2.3 to 10.2. In surface points along the dam, 230Th activity concentration decreases while 232Th concentration remains constant. On the other hand, activity concentrations of both isotopes showed a pointed out enhancement with depth. The results have shown a possible lixiviation of uranium from geological substrate into the surface water and an important fractionation of thorium isotopes, which suggest that thorium is non-homogeneously distributed along San Marcos dam.

  6. Reliablity analysis of gravity dams by response surface method

    Science.gov (United States)

    Humar, Nina; Kryžanowski, Andrej; Brilly, Mitja; Schnabl, Simon

    2013-04-01

    A dam failure is one of the most important problems in dam industry. Since the mechanical behavior of dams is usually a complex phenomenon existing classical mathematical models are generally insufficient to adequately predict the dam failure and thus the safety of dams. Therefore, numerical reliability methods are often used to model such a complex mechanical phenomena. Thus, the main purpose of the present paper is to present the response surface method as a powerful mathematical tool used to study and foresee the dam safety considering a set of collected monitoring data. The derived mathematical model is applied to a case study, the Moste dam, which is the highest concrete gravity dam in Slovenia. Based on the derived model, the ambient/state variables are correlated with the dam deformation in order to gain a forecasting tool able to define the critical thresholds for dam management.

  7. Discussion on construction and type selection of China high dams

    Institute of Scientific and Technical Information of China (English)

    Zhou Jianping; Yang Zeyan; Chen Guanfu

    2009-01-01

    At the beginning of 21st century, with the rapid and steady development of China economy, a lot of large scale hydropower projects with large dams from 200 m to 300 m high are being or to be buih. China dam constructions are reaching the level of 300 m high arch dam, 250 high CFRD (concrete face rockfill dam) and 200 m high RCC (roller compacted concrete) gravity dam. Due to the safety and the economy, the type selection for high dams has become the key issue during the argumentation for the hydropower projects, and further efforts are still needed in this aspect for high dams. After reviewing the high dam constructions in China and abroad, authors proposed some advices for the selection of dam types, and hope that it can provide some helpful information for the researches and the design of high dams.

  8. 76 FR 34799 - Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN

    Science.gov (United States)

    2011-06-14

    ... Permanent Dam Safety Modification at Cherokee, Fort Loudoun, Tellico, and Watts Bar Dams, TN AGENCY... various alternatives for permanent modifications to the existing dam facilities at Cherokee, Fort Loudoun, Tellico, and Watts Bar dams in Tennessee. The level of review will be determined after the public...

  9. Determination of Seepage and Analysis of Earth Dams (Case Study: Karkheh Dam

    Directory of Open Access Journals (Sweden)

    A. Kamanbedast

    2011-01-01

    Full Text Available Because of the increasing trend of building dam throughout Iran; it is necessary to optimize dam buildings and operations. Dam or Hydropower industry has two types of buildings; normally: (1 Concrete dams (2 Embankment (earth dams. Generally, scientists and engineers use different methods to enhance safety and decrease any errors in calculation due to maintenance of water storage especially hydro structure of the dam. It is necessary to investigate the dam seepage control; commonly used by several methods. Seepage is one of the important issues for design, build and maintenance of dams awareness. Seepage problem and its rules helps scientist to select a suitable method of monitoring and solving such problem. These methods of analysis were carried out at civil and construction project. In this study, one of latest method of investigation of seepage behavior were analytically evaluated and compared with the actual rules. Based on determine results; several suggestions and optimization method were suggested. Therefore, an optimum method was scientifically selected. Besides that, flow condition of porous environment with application of numeric program was analyzed. Finally, all the results were lunched out from seep/w soft which is the most significant program about this matter; use of finite elements method is specified for saturated and unsaturated environment. Thus; leakage and seepage were defined as function of (time and position. Subsequently, the best seepage solutions for the dam constructing were scientifically identified.

  10. Analysis of seismic disaster failure mechanism and dam-break simulation of high arch dam

    Science.gov (United States)

    Zhang, Jingkui; Zhang, Liaojun

    2014-06-01

    Based on a Chinese national high arch dam located in a meizoseismal region, a nonlinear numerical analysis model of the damage and failure process of a dam-foundation system is established by employing a 3-D deformable distinct element code (3DEC) and its re-development functions. The proposed analysis model considers the dam-foundation-reservoir coupling effect, influence of nonlinear contact in the opening and closing of the dam seam surface and abutment rock joints during strong earthquakes, and radiation damping of far field energy dissipation according to the actual workability state of an arch dam. A safety assessment method and safety evaluation criteria is developed to better understand the arch dam system disaster process from local damage to ultimate failure. The dynamic characteristics, disaster mechanism, limit bearing capacity and the entire failure process of a high arch dam under a strong earthquake are then analyzed. Further, the seismic safety of the arch dam is evaluated according to the proposed evaluation criteria and safety assessment method. As a result, some useful conclusions are obtained for some aspects of the disaster mechanism and failure process of an arch dam. The analysis method and conclusions may be useful in engineering practice.

  11. Long-term dam safety monitoring of Punt dal Gall arch dam in Switzerland

    Institute of Scientific and Technical Information of China (English)

    M.WIELAND[1; G.F.KIRCHEN[2

    2012-01-01

    The 130 m high Punt dal Gall dam is located at the Swiss-Italian border in the South-eastern part of Switzerland and was completed in 1969.The dam is founded on highly folded and partially crushed dolomite and limestone formations.A grout curtain with an area of 120,000 m 2 was provided for controlling seepage.For the monitoring of the dam deformations five inverted pendulums were installed in the dam and three in the rock foundation of the right abutment outside of the dam.For a seasonal water level fluctuation in the reservoir of about 60 m the maximum amplitude of the radial displacement is 25 mm,which includes both the effects of the water load and temperature effects.Furthermore a comprehensive geodetic network was established,57 joint meters were installed and cracks in the crest gallery are monitored by crack meters.There are also thermometers,piezometers and rocmeters.Springs at the left and right banks of the dam are monitored and chemical analyses of the seepage water and springs are performed regularly.The dam is equipped with strong motion instruments and several near-field earthquakes have been recorded in the past.The paper describes the long-term safety monitoring of this 42 years old arch dam.A short description of the Swiss practice in dam safety monitoring and emergency planning is also given.

  12. Numerical Study of Two-Dimensional Viscous Flow over Dams

    Institute of Scientific and Technical Information of China (English)

    王利兵; 刘宇陆; 涂敏杰

    2003-01-01

    In this paper, the characteristics of two-dimensional viscous flow over two dams were numerically investigated. The results show that the behavior of the vortices is closely related to the space between two dams, water depth, Fr number and Reynolds number. In addition, the flow properties behind each dam are different, and the changes over two dams are more complex than over one dam. Finally, the relevant turbulent characteristics were analyzed.

  13. Research on Dam Simulation System Based on OpenGL

    Science.gov (United States)

    Li, Kairong; Wang, Juanni; Zuo, Kui; Yun, Jian

    Dam, not only has great ability to alleviate water shortages especially during the dry season which improve hydropower capacity, but also plays an imporant rule in the river ecosystem. Dam has significant effect in improving our water environment and protecting ecological system.This paper copes with the three-dimensional model of dams and discusses OpenGL modeling, lighting, material, model transformation, perspective transformation technologies to achieve visualization of the dam, and eventually we visualize the dam through concrete examples.

  14. Final Design Analysis : Lake Ladora Dam Repair

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is intended to present Rocky Mountain Arsenal with details concerning the remedial repair for Ladora Dam to meet the geotechnical concerns and hydrologic...

  15. Chemical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  16. Dams life; La vie des barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This paper summarizes the conclusions of the annual inspections of French dams in operation (fissures, water oozing, concrete swelling etc..). Only the observations which require a special attention are reported. (J.S.)

  17. White Sturgeon Passage at The Dalles Dam

    Science.gov (United States)

    ,

    2008-01-01

    Researchers at the USGS Western Fisheries Research Center's Columbia River Research Laboratory, working with the U.S. Army Corps of Engineers, sought to better understand upstream and downstream passage of white sturgeon at dams. A study at The Dalles Dam provided the opportunity to compare two fish ladders; one that passes sturgeon upstream to one that does not, to determine if subtle differences in construction result in better passage of white sturgeon. Researchers conducted a study using a combination of acoustic and radio telemetry technologies to obtain information on juvenile and adult white sturgeon near The Dalles Dam, with the objectives of characterizing the distribution and movements of white sturgeon in the immediate vicinity of the dam and to determine timing and routes of upstream and downstream passage.

  18. Physical - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  19. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  20. Risk assessment of tailings facility dam failure

    OpenAIRE

    Hadzi-Nikolova, Marija; Mirakovski, Dejan; Stefanova, Violeta

    2011-01-01

    This paper presents the consequences of tailings facility dam failure and therefore the needs for its risk assessment. Tailings are fine-grained wastes of the mining industry, output as slurries, due to mixing with water during mineral processing. Tailings dams vary a lot as it is affected by: tailings characteristics and mill output, site characteristics as: topography, hydrology, geology, groundwater, seismicity and available material and disposal methods. The talings which accumulat...

  1. Stability and performance of older dams

    Energy Technology Data Exchange (ETDEWEB)

    Dharmawardene, W.; Herbig, A.; Morrison, J. [Alberta Environment, AB (Canada); Chan, D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2003-07-01

    There are 1300 licensed dams in Alberta. Most were designed and constructed between the late 1940s and the early 1960s. As a rule, compacted earthfill in preglacial and interglacial valleys in southern Alberta was used to construct all dams of moderate height. At these dam sites, the foundations are of valley infill alluvial soils underlain by weak rocks. The best prevailing engineering practices at the time were used to design these dams. It included drilling, soil testing prior to and during construction, and some stability analyses. Despite these measures, a number of the dams built on soft clays suffered significant deformations and cracking of the embankment during construction. A re-examination of the stability of some of the older dams in Alberta, owned by the provincial department of the Environment, was undertaken six years ago using currently accepted design practices. Allowance was made in the new analyses for the presence of shear zones and fissures in the foundation soils, as well as softening caused by wetting. Despite many years of apparently satisfactory service, Factors of Safety that were marginal or deficient were discovered at many dams. The authors presented case histories of three older dams (North and South McGregor, and North Ridge, all located in southern Alberta) for which the long term Factors of Safety were marginal under normal loading. A number of criteria, such as deformation, stress strain curves of foundation materials and the consequence of failure were taken into consideration in assessing and confirming the requirement for repair before any structural modifications were undertaken. Some of the repairs that were carried out were also briefly described. 12 refs., 4 tabs., 5 figs.

  2. HYDRAULIC SIMULATION OF FLASH FLOOD AS TRIGGERED BY NATURAL DAM BREAK

    Directory of Open Access Journals (Sweden)

    Yanuar Tri Kurniawan

    2015-05-01

    Calibration model result showed that the height of natural dam significantly influence changes of water surface elevation at control point. Tracing of flood result in reconstruction of January 2006 flood showed the conformity with the real event. It was observed from the arrival time of flood at certain location. From obtained results, it can be concluded that simulation modeling gave the acceptable results.

  3. An updated numerical simulation of the ground-water flow system for the Castle Lake debris dam, Mount St. Helens, Washington, and implications for dam stability against heave

    Science.gov (United States)

    Roeloffs, Evelyn A.

    1994-01-01

    A numerical simulation of the ground-water flow system in the Castle Lake debris dam, calibrated to data from the 1991 and 1992 water years, was used to estimate factors of safety against heave and internal erosion. The Castle Lake debris dam, 5 miles northwest of the summit of Mount St. Helens, impounds 19,000 acre-ft of water that could pose a flood hazard in the event of a lake breakout. A new topographic map of the Castle Lake area prior to the 1980 eruption of Mount St. Helens was prepared and used to calculate the thickness of the debris avalanche deposits that compose the dam. Water levels in 22 piezometers and discharges from seeps on the dam face measured several times per year beginning in 1990 supplemented measurements in 11 piezometers and less frequent seep discharge measurements made since 1983. Observations in one group of piezometers reveal heads above the land surface and head gradients favoring upward flow that correspond to factors of safety only slightly greater than 2. The steady-state ground-water flow system in the debris dam was simulated using a threedimensional finite difference computer program. A uniform, isotropic model having the same shape as the dam and a hydraulic conductivity of 1.55 ft/day simulates the correct water level at half the observation points, but is in error by 10 ft or more at other points. Spatial variations of hydraulic conductivity were required to calibrate the model. The model analysis suggests that ground water flows in both directions between the debris dam and Castle Lake. Factors of safety against heave and internal erosion were calculated where the model simulated upward flow of ground water. A critical gradient analysis yields factors of safety as low as 2 near the piezometers where water level observations indicate low factors of safety. Low safety factors are also computed near Castle Creek where slumping was caused by a storm in January, 1990. If hydraulic property contrasts are present in areas of the

  4. Walter Bouldin Dam failure and reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-09-01

    Walter Bouldin is one of several hydroelectric developments of Alabama Power Company. On February 10, 1975, an earth embankment section of Walter Bouldin Dam was breached, causing total evacuation of the forebay reservoir and rendering the 225-MW power plant inoperable. The Federal Power Commission instituted an investigation of the dam failure, and a report on the investigation was published in February 1976. Subsequently, an evidentiary hearing was held before an administrative law judge who issued his initial decision on August 19, 1976. The Commission, on April 21, 1977, issued its Opinion No. 795 in which it adopted the initial decision with modifications and terminated the investigation of failure of Walter Bouldin Dam. Opinion No. 795 directs the staff of the Bureau of Power to prepare, for the future guidance of the Commission, a report on the deficiencies which were found in its investigation, together with advice as to how such deficiencies have been and should be remedied. Also, it directs the staff of the Bureau of Power to address certain general recommendations included in the initial decision. This report was prepared in response to that directive and summaries information on the dam failure and its investigation; the evidentiary hearing; the judge's recommendations, the reconstruction of the Bouldin Dam; and the evalution and status of the Federal Energy Regulatory Commission Dam safety program. (LCL)

  5. Reliability Analysis of High Rockfill Dam Stability

    Directory of Open Access Journals (Sweden)

    Ping Yi

    2015-01-01

    Full Text Available A program 3DSTAB combining slope stability analysis and reliability analysis is developed and validated. In this program, the limit equilibrium method is utilized to calculate safety factors of critical slip surfaces. The first-order reliability method is used to compute reliability indexes corresponding to critical probabilistic surfaces. When derivatives of the performance function are calculated by finite difference method, the previous iteration’s critical slip surface is saved and used. This sequential approximation strategy notably improves efficiency. Using this program, the stability reliability analyses of concrete faced rockfill dams and earth core rockfill dams with different heights and different slope ratios are performed. The results show that both safety factors and reliability indexes decrease as the dam’s slope increases at a constant height and as the dam’s height increases at a constant slope. They decrease dramatically as the dam height increases from 100 m to 200 m while they decrease slowly once the dam height exceeds 250 m, which deserves attention. Additionally, both safety factors and reliability indexes of the upstream slope of earth core rockfill dams are higher than that of the downstream slope. Thus, the downstream slope stability is the key failure mode for earth core rockfill dams.

  6. OVERVIEW OF DAM GULLY EROSION RESEARCH

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Traditionally gully erosion has been identified with the dissection of the landscape in agricultural settings but it is also recognized as a prevalent erosion feature in earthen dam auxiliary spillways and embankments. Flows through earthen spillways and over dam embankments, due to large rainfall events, have the potential to erode and breach the dam or spillway and result in catastrophic releases from the reservoir. The gully erosion process in an earthen spillway or on an embankment can be characterized by stages of initiation, development, and migration of a headcut. A headcut is defined as a near vertical drop at the upstream end of a gully. The rate of headcut migration is important in determining the breach potential of an earthen spillway and dam embankment. A research program is being conducted to examine the gully erosion processes of earthen dam auxiliary spillways and embankments. This paper describes: 1) the unique test facilities constructed to examine the dominant factors affecting the erosion of earthen spillways and embankments; 2) the observations of the erosion processes and results to date; and 3) the predictive relationships that have been developed for dam gully erosion research at the ARS Hydraulic Engineering Research Unit laboratory in Stillwater, OK.

  7. Distributional Impacts of Large Dams in China

    Science.gov (United States)

    Bao, X.

    2010-12-01

    Dams on a river are believed to have heterogeneous impacts to the upstream, local and downstream areas. Generally, irrigation dams will bring benefits to the downstream by facilitating more irrigation, while it will bring negative impacts to upstream due to inundation or no impact to local area as a combination result of population dislocation and economic benefits. This paper checked the impacts of large dams (above 100 meters) on the upstream, downstream and local area, using 2000-2008 county level data in China. Robust heterogeneous impacts of different categories of dams (mainly dams serving for irrigation, hydropower, or other purposes) were found on different areas, using IV regression approaches. Dams higher than 100 meters are significantly and heterogeneously impacting agricultural production, urban employment and rural per capita income. Its beneficial impact on agriculture production is significant for downstream especially in continuous drought years. But its impacts on social welfare indicators, such as primary school enrollment and hospital beds, are not heterogeneously different across regions.

  8. Estimating flood inundation caused by dam failures

    Energy Technology Data Exchange (ETDEWEB)

    Mocan, N. [Crozier and Associates Inc., Collingwood, ON (Canada); Joy, D.M. [Guelph Univ., ON (Canada). School of Engineering; Rungis, G. [Grand River Conservation Authority, Cambridge, ON (Canada)

    2006-01-15

    Recent advancements in modelling inundation due to dam failures have allowed easier and more illustrative analyses of potential outcomes. This paper described new model and mapping capabilities available using the HEC-RAS hydraulic model in concert with geographic information systems (GIS). The study area was the upper reaches of Canagagigue Creek and the Woolwich Dam near Elmira, Ontario. A hydraulic analysis of a hypothetical dam failure was developed based on the summer probable maximum flood (PMF) event. Limits extended from Woolwich Dam to downstream of the Town of Elmira. An incoming summer PMF hydrograph was set as the upstream boundary condition in the upstream model. Simulation parameters include simulation time-step; implicit weighting factor; water surface calculation tolerance; and output calculation interval. Peak flows were presented, as well as corresponding flood inundation results through the Town of Elmira. The hydraulic model results were exported to a GIS in order to develop inundation maps for emergency management planning. Results from post-processing included inundation maps for each of the simulated time-steps as well as an inundation animation for the duration of the dam breach. It was concluded that the modelling tools presented in the study can be applied to other dam safety assessment projects in order to develop effective and efficient emergency preparedness plans through public consultation and the establishment of impact zones. 1 tab., 2 figs.

  9. Post-Hurricane Sandy coastal oblique aerial photographs collected from Cape Lookout, North Carolina, to Montauk, New York, November 4-6, 2012

    Science.gov (United States)

    Morgan, Karen L.M.; Krohn, M. Dennis

    2014-01-01

    The U.S. Geological Survey (USGS) conducts baseline and storm response photography missions to document and understand the changes in vulnerability of the Nation's coasts to extreme storms. On November 4-6, 2012, approximately one week after the landfall of Hurricane Sandy, the USGS conducted an oblique aerial photographic survey from Cape Lookout, N.C., to Montauk, N.Y., aboard a Piper Navajo Chieftain (aircraft) at an altitude of 500 feet (ft) and approximately 1,000 ft offshore. This mission was flown to collect post-Hurricane Sandy data for assessing incremental changes in the beach and nearshore area since the last survey in 2009. The data can be used in the assessment of future coastal change. The photographs provided here are Joint Photographic Experts Group (JPEG) images. The photograph locations are an estimate of the position of the aircraft and do not indicate the location of the feature in the images. These photos document the configuration of the barrier islands and other coastal features at the time of the survey. Exiftool was used to add the following to the header of each photo: time of collection, Global Positioning System (GPS) latitude, GPS longitude, keywords, credit, artist (photographer), caption, copyright, and contact information. Photographs can be opened directly with any JPEG-compatible image viewer by clicking on a thumbnail on the contact sheet. Table 1 provides detailed information about the GPS location, image name, date, and time each of the 9,481 photographs were taken, along with links to each photograph. The photographs are organized in segments, also referred to as contact sheets, and represent approximately 5 minutes of flight time. In addition to the photographs, a Google Earth Keyhole Markup Language (KML) file is provided and can be used to view the images by clicking on the marker and then clicking on either the thumbnail or the link above the thumbnail. The KML files were created using the photographic navigation files.

  10. Use and application of inflatable dam seals in large concrete dams

    Energy Technology Data Exchange (ETDEWEB)

    Dickes, G. [Structural Preservation Systems Inc., Hanover, MD (United States)

    2001-10-01

    The successful installation of inflatable dam seals has been accomplished at several large concrete dams in the United States. This accomplishment was recently realized for the first time in Canada. The minimization of water intrusion caused by failed water stops in monolithic dams by a small diameter inflatable seal is one of the many uses for the device. Many problems encountered at large concrete dams are related to stress control of alkali-aggregate or alkali silica reaction (AAR, ASR), and the inflatable dam seal fits in as part of this control system. Many of the problems with concrete dams are due to AAR which causes concrete to expand, resulting in cracking of concrete and misalignment of equipment as two of the most important issues. A transverse vertical saw cut through the upper section of the concrete structure was one of the methods used to alleviate the stresses brought about by AAR. This method has been used on a number of occasions in both Canada and the United States. Once the saw cut is complete, from the upstream face to the downstream face, controlling the water flow in the kerf (13-19 millimeter) presents a major challenge. Successfully sealing failed water stops and saw cuts was accomplished by installing inflatable dam seals with vertical heights in excess of 38 meters. A specific seal must be designed in each case. Several elements of the composite construction seal meet the engineering requirements set forth by Dam Safety Officials and Engineers and Owners. Some case histories were presented, namely the Harry S. Truman Dam in Missouri, the Tennessee Valley Authority at several sites, the Hiwassee Dam in North Carolina, the Fontana Dam in Tennessee, and the Mactaquac Generating Station in New Brunswick. 10 refs., 11 figs.

  11. How stakeholders frame dam removal: The role of current and anticipated future ecosystem service use

    Science.gov (United States)

    Reilly, Kate; Adamowski, Jan

    2016-04-01

    Many river restoration projects, including dam removal, are controversial and can trigger conflicts between stakeholders who are for and against the proposed project. The study of environmental conflicts suggests that differences in how stakeholders 'frame', or make sense of a situation based on their prior knowledge and experiences, can perpetuate conflicts. Understanding different stakeholders' frames, particularly how they converge, can form the basis of successful conflict resolution. In the case of dam removals, it is often assumed that emphasising increased provision of ecosystem services can be a point of convergence between those advocating for ecological restoration and those opposed to removal because of negative human impacts. However, how exactly stakeholders frame a contentious proposed dam removal and how those frames relate to ecosystem services has been little studied. Here we used the case of a potential dam removal in New Brunswick to investigate how people frame the issue and how that relates to their current and anticipated future use of ecosystem services. Based on in-depth interviews with 30 stakeholders in the area, including both people for and against dam removal, we found that both groups currently used ecosystem services and were in favour of ecosystem protection. However, they differed in how they framed the issue of the potential dam removal. The group against dam removal framed the issue as one of loss and risk - they thought that any potential benefits to the ecosystem would be outweighed by the high risk of negative social impacts caused by a loss of access to ecosystem services, such as recreation and aesthetic enjoyment. By contrast, the group in favour of the dam framed the issue as one of opportunity and justice. They thought that following a short transition period, all stakeholders would benefit from the restored river, particularly from a restored salmon fishery, improved aesthetic appeal and the long-term sustainability of an

  12. Game model of safety monitoring for arch dam deformation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Arch dam deformation is comprehensively affected by water pressure,temperature,dam’s structural behavior and material properties as well as other factors.Among them the water pressure and temperature are external factors(source factors) that cause dam deformation,and dam’s structural behavior and material properties are the internal factors of deformation(resistance factors).The dam deformation is the result of the mutual game playing between source factors and resistance factors.Therefore,resistance factors of structure and materials that reflect resistance character of arch dam structure are introduced into the traditional model,where structure factor is embodied by the flexibility coefficient of dam body and the maximum dam height,and material property is embodied by the elastic modulus of dam.On the basis of analyzing the correlation between dam deformation and resistance factors,the game model of safety monitoring for arch dam deformation is put forward.

  13. The interplay of activists and dam developers : the case of Myanmar’s mega-dams

    NARCIS (Netherlands)

    Kirchherr, Julian; J. Charles, Katrina; Walton, Matthew J.

    2017-01-01

    Scholars investigating activism against large dam developments in Asia usually focus on those campaigning, but not on those the campaigns are aimed at–the dam developers. Yet the developers’ perspective is crucial to comprehensively understand the dynamics of social and environmental activism in

  14. Application of Probabilistic Method to Stability Analysis of Gravity Dam Foundation over Multiple Sliding Planes

    Directory of Open Access Journals (Sweden)

    Gang Wang

    2016-01-01

    Full Text Available The current challenge to the engineering profession is to carry out probabilistic methods in practice. The design point method in generalized random space (DPG method associated with the method of divided difference can be utilized to deal with the complex problem of probability calculation of implicit performance function with nonnormal and correlated variables. For a practical concrete gravity dam, the suggested method is performed to calculate the instability probability of the dam foundation over multiple sliding places. The general conclusions drawn in the paper are identical to those in other research and the method is proved to be feasible, accurate, and efficient. As the same analysis principle, the method can also be used in other similar fields, such as in fields of slopes, earth-rock dams, levees, and embankments.

  15. Triclosan exposure reduces thyroxine levels in pregnant and lactating rat dams and in directly exposed offspring

    DEFF Research Database (Denmark)

    Petersen, Marta Axelstad; Boberg, Julie; Vinggaard, Anne Marie

    2013-01-01

    Thyroid disrupting chemicals can potentially disrupt brain development. Two studies investigating the effect of the antibacterial compound triclosan on thyroxine (T4) levels in rats are reported. In the first, Wistar rat dams were gavaged with 75, 150 or 300 mg triclosan/kg bw/day throughout...... gestation and lactation. Total T4 serum levels were measured in dams and offspring, and all doses of triclosan significantly lowered T4 in dams, but no significant effects on T4 levels were seen in the offspring at the end of the lactation period. Since this lack of effect could be due to minimal exposure...... through maternal milk, a second study using direct per oral pup exposure from postnatal day 3–16 to 50 or 150 mg triclosan/kg bw/day was performed. This exposure pointed to significant T4 reductions in 16 day old offspring in both dose groups. These results corroborate previous studies showing...

  16. Ambient modal testing of a double-arch dam: the experimental campaign and model updating

    Science.gov (United States)

    García-Palacios, Jaime H.; Soria, José M.; Díaz, Iván M.; Tirado-Andrés, Francisco

    2016-09-01

    A finite element model updating of a double-curvature-arch dam (La Tajera, Spain) is carried out hereof using the modal parameters obtained from an operational modal analysis. That is, the system modal dampings, natural frequencies and mode shapes have been identified using output-only identification techniques under environmental loads (wind, vehicles). A finite element model of the dam-reservoir-foundation system was initially created. Then, a testing campaing was then carried out from the most significant test points using high-sensitivity accelerometers wirelessly synchronized. Afterwards, the model updating of the initial model was done using a Monte Carlo based approach in order to match it to the recorded dynamic behaviour. The updated model may be used within a structural health monitoring system for damage detection or, for instance, for the analysis of the seismic response of the arch dam- reservoir-foundation coupled system.

  17. Space geodetic monitoring of engineered structures: The ongoing destabilization of the Mosul dam, Iraq.

    Science.gov (United States)

    Milillo, Pietro; Bürgmann, Roland; Lundgren, Paul; Salzer, Jacqueline; Perissin, Daniele; Fielding, Eric; Biondi, Filippo; Milillo, Giovanni

    2016-12-06

    We present a detailed survey of the ongoing destabilization process of the Mosul dam. The dam is located on the Tigris river and is the biggest hydraulic structure in Iraq. From a geological point of view the dam foundation is poor due to a site geology formed by alternating strata of highly soluble materials including gypsum, anhydrite, marl and limestone. Here we present the first multi-sensor cumulative deformation map for the dam generated from space-based interferometric synthetic aperture radar measurements from the Italian constellation COSMO-SkyMed and the European sensor Sentinel-1a over the period 2014-2016 that we compare to an older dataset spanning 2004-2010 acquired with the European Envisat satellite. We found that deformation was rapid during 2004-2010, slowed in 2012-2014 and increased since August 2014 when grouting operations stopped due to the temporary capture of the dam by the self proclaimed Islamic State. We model the inferred deformation using a Markov chain Monte Carlo approach to solve for change in volume for simple tensile dislocations. Results from recent and historical geodetic datasets suggests that the volume dissolution rate remains constant when the equivalent volume of total concrete injected during re-grouting operations is included in the calculations.

  18. Geographical Overview of the Three Gorges Dam and Reservoir, China - Geologic Hazards and Environmental Impacts

    Science.gov (United States)

    Highland, Lynn M.

    2008-01-01

    The Three Gorges Dam and Reservoir on the Yangtze River, China, has been an ambitious and controversial project. The dam, the largest in the world as of 2008, will provide hydropower, help to manage flood conditions, and increase the navigability of the Yangtze River. However, this massive project has displaced human and animal populations and altered the stability of the banks of the Yangtze, and it may intensify the seismic hazard of the area. It has also hindered archeological investigations in the reservoir and dam area. This report, originally in the form of a Microsoft PowerPoint presentation, gives a short history and overview of the dam construction and subsequent consequences, especially geologic hazards already noted or possible in the future. The report provides photographs, diagrams, and references for the reader's further research - a necessity, because this great undertaking is dynamic, and both its problems and successes continue to evolve. The challenges and consequences of Three Gorges Dam will be closely watched and documented as lessons learned and applied to future projects in China and elsewhere.

  19. Space geodetic monitoring of engineered structures: The ongoing destabilization of the Mosul dam, Iraq

    Science.gov (United States)

    Milillo, Pietro; Bürgmann, Roland; Lundgren, Paul; Salzer, Jacqueline; Perissin, Daniele; Fielding, Eric; Biondi, Filippo; Milillo, Giovanni

    2016-12-01

    We present a detailed survey of the ongoing destabilization process of the Mosul dam. The dam is located on the Tigris river and is the biggest hydraulic structure in Iraq. From a geological point of view the dam foundation is poor due to a site geology formed by alternating strata of highly soluble materials including gypsum, anhydrite, marl and limestone. Here we present the first multi-sensor cumulative deformation map for the dam generated from space-based interferometric synthetic aperture radar measurements from the Italian constellation COSMO-SkyMed and the European sensor Sentinel-1a over the period 2014-2016 that we compare to an older dataset spanning 2004-2010 acquired with the European Envisat satellite. We found that deformation was rapid during 2004-2010, slowed in 2012-2014 and increased since August 2014 when grouting operations stopped due to the temporary capture of the dam by the self proclaimed Islamic State. We model the inferred deformation using a Markov chain Monte Carlo approach to solve for change in volume for simple tensile dislocations. Results from recent and historical geodetic datasets suggests that the volume dissolution rate remains constant when the equivalent volume of total concrete injected during re-grouting operations is included in the calculations.

  20. Monitoring of the Earth's surface deformation in the area of water dam Zarnowiec

    Science.gov (United States)

    Mojzes, Marcel; Wozniak, Marek; Habel, Branislav; Macak, Marek

    2017-04-01

    Mathematical and physical research directly motivates geodetic community which can provide very accurate measurements for testing of the proposed models Earth's surface motion near the water dams should be monitored due to the security of the area. This is a process which includes testing of existing models and their physical parameters. Change of the models can improve the practical results for analyzing the trends of motion in the area of upper reservoir of water dam Zarnowiec. Since 1998 Warsaw University of Technology realized a research focused on the horizontal displacements of the upper reservoir of water dam Zarnowiec. The 15 selected control points located on the upper reservoir crown of the water dam were monitored by classical distance measurements. It was found out that changes in the object's geometry occur due to the variation of the water level. The control measurements of the changes in the object's geometry occurring during the process of emptying and filling of the upper reservoir of water dam were compared with the deformations computed using improved Boussinesqués method programmed in the software MATLAB and ANSYS for elastic and isotropic half space as derivation of suitable potentials extended to the loaded region. The details and numerical results of this process are presented This presentation was prepared within the project "National Centre for Diagnostic of the Earth's Surface Deformations in the Area of Slovakia", ITMS code: 26220220108.

  1. Design and construction of Nemiscau-1 Dam, the first asphalt core rockfill dam in North America

    Energy Technology Data Exchange (ETDEWEB)

    Alicescu, V.; Tournier, J.P. [Hydro-Quebec, Montreal, PQ (Canada); Vannobel, P. [Societe d' Energie de la Baie James, Montreal, PQ (Canada)

    2008-07-01

    The concept of asphalt as a waterproofing medium inside embankment dams was originally developed in Germany in the 1960s. More than 100 asphalt core rockfill (ACRD) dams have been completed or are under construction. They all have a strong record without any seepage problems or required maintenance. After using the glacial till as waterproofing material for its embankment dams for more than 50 years, Hydro-Quebec is now looking to develop new dam concepts, mainly for the zones where natural waterproofing materials do not exist. In order to do so, the company has decided to design and construct the Nemiscau-1 Dam as a prototype ACRD. This paper presented the detailed design criteria, technical specifications as well as some information concerning the construction of the dam such as asphalt mix design. The given dam site, geology and materials is well suited for a dam with an asphalt core and the chosen core thickness of minimum 400 mm was found to be appropriate, given the small net water head. The main reservoir levels as well as the characteristics of the dam were also listed. Information on the general construction of the dam was provided. It was concluded that the longitudinal profile of the rock excavation and concrete plinth must be optimized, with an optimum balance between the rock excavation, the volume and shape of the concrete plinth and finally, the placement of the asphalt core with the manual method. Several combinations of these 3 elements must be analyzed at the design stage and the most cost effective one should be applied on site. 5 tabs., 7 figs.

  2. EXPERIMENTAL INVESTIGATION OF THE FAILURE OF CASCADE LANDSLIDE DAMS

    Institute of Scientific and Technical Information of China (English)

    NIU Zhi-pan; XU Wei-lin; LI Nai-wen; XUE Yang; CHEN Hua-yong

    2012-01-01

    This paper preseuts results of model tests for the landslide dam failure of a single dam and cascade dams in a sloping channel.The dams were designed to be regular trapezoid with fine sand.A new measuring method named the labeled line locating method was used to digitalize the captured instantaneous pictures.Under two differem inflow discharges,the morphological evolution and the flow patterns during one dam failure and the failure of cascade dams were investigated.The results indicate that when the inflow discharge is large,the deformation pattern of the downstream dam is similar to that of the upstream dam,and both dams are characterized with the overtopping scour throughout the dam failure process.When the inflow discharge is small,the upstream dam is scoured mainly through a sluice slot formed by the longitudinal incision,and the downstream dam is characterized with the overtopping scour.The data set presented in this paper can be used for the validation of numerical models and provide a reference for the flood risk management of cascade landslide dams.

  3. Toward policies and decision-making for dam removal.

    Science.gov (United States)

    Doyle, Martin W; Harbor, Jon M; Stanley, Emily H

    2003-04-01

    Dam removal has emerged as a critical issue in environmental management. Agencies responsible for dams face a drastic increase in the number of potential dam removals in the near future. Given limited resources, these agencies need to develop ways to decide which dams should be removed and in what order. The underlying science of dam removal is relatively undeveloped and most agencies faced with dam removal lack a coherent purpose for removing dams. These shortcomings can be overcome by the implementation of two policies by agencies faced with dam removal: (1) the development and adoption of a prioritization scheme for what constitutes an important dam removal, and (2) the establishment of minimum levels of analysis prior to decision-making about a dam removal. Federal and state agencies and the scientific community must encourage an initial experimental phase of dam removal during which only a few dams are removed, and these are studied intensively. This will allow for the development of the fundamental scientific understanding needed to support effective decision-making in the future and minimize the risk of disasters arising from poorly thought out dam removal decisions.

  4. International small dam safety assurance policy benchmarks to avoid dam failure flood disasters in developing countries

    Science.gov (United States)

    Pisaniello, John D.; Dam, Tuyet Thi; Tingey-Holyoak, Joanne L.

    2015-12-01

    In developing countries small dam failure disasters are common yet research on their dam safety management is lacking. This paper reviews available small dam safety assurance policy benchmarks from international literature, synthesises them for applicability in developing countries, and provides example application through a case study of Vietnam. Generic models from 'minimum' to 'best' practice (Pisaniello, 1997) are synthesised with the World Bank's 'essential' and 'desirable' elements (Bradlow et al., 2002) leading to novel policy analysis and design criteria for developing countries. The case study involved 22 on-site dam surveys finding micro level physical and management inadequacies that indicates macro dam safety management policy performs far below the minimum benchmark in Vietnam. Moving assurance policy towards 'best practice' is necessary to improve the safety of Vietnam's considerable number of hazardous dams to acceptable community standards, but firstly achieving 'minimum practice' per the developed guidance is essential. The policy analysis/design process provides an exemplar for other developing countries to follow for avoiding dam failure flood disasters.

  5. Re-grouting of Maroon Dam foundation

    Energy Technology Data Exchange (ETDEWEB)

    Palassi, M. [Tehran Univ. (Iran, Islamic Republic of). Dept. of Civil Engineering; Sharghi, A. [JTMA Co., Tehran (Iran, Islamic Republic of)

    2003-07-01

    The Maroon dam, built on the Maroon River in the Khoozestan province (southwest) of Iran, has a height of 176 metres and a 1.2 billion cubic metre reservoir. It is one of the largest embankment dams in Iran. A number of unpredicted inflows of water into tunnels and other underground openings occurred during the first impoundment of the Maroon dam. Impoundment was halted and the reservoir was emptied to correct the problem. This paper reviews the measures that were implemented during the remediation process, and presented an evaluation of the effectiveness of the process. The foundation treatment involved placing concrete in the caverns, constructing a concrete lining, and extending the grout curtain. The grouting procedure was also described. The overall effectiveness of the concrete work and grouting resulted in a reduction in leakage from 8.5 cubic metres per second to a more acceptable 10 litres per second. 8 figs.

  6. Channel changes downstream from a dam

    Science.gov (United States)

    Hadley, R.F.; Emmett, W.W.

    1998-01-01

    A flood-control dam was completed during 1979 on Bear Creek, a small tributary stream to the South Platte River in the Denver, Colorado, area. Before and after dam closure, repetitive surveys between 1977 and 1992 at five cross sections downstream of the dam documented changes in channel morphology. During this 15-year period, channel width increased slightly, but channel depth increased by more than 40 percent. Within the study reach, stream gradient decreased and median bed material sizes coarsened from sand in the pools and fine gravel on the riffle to a median coarse gravel throughout the reach. The most striking visual change was from a sparse growth of streamside grasses to a dense growth of riparian woody vegetation.

  7. Design of tailing dam using red mud

    Science.gov (United States)

    Rout, Subrat; Sahoo, Tapaswini; Das, Sarat

    2013-06-01

    Red mud, waste industrial product from aluminum industries produced approximately 75 million tonnes every year with less than half of this is used. Storage of this unutilized red mud takes vast tracts of usable land and pollutes, land, air and water. Construction of high embankments, under passes, flyovers, tailing dams uses vast tract of natural resources (top soil) is also matter of concern as its takes thousands of years to form the natural soil. This paper discusses use of red mud for construction of tailing dam based on laboratory findings and finite element analysis. The geotechnical properties such as plasticity, compaction, permeability, shear strength characteristics and dispersion of red mud are presented. Stability and seepage analysis of tailing dams as per finite element analysis using the above geotechnical parameters is presented.

  8. Study on dynamic anti-sliding stability of a high gravity dam considering complex dam foundation

    Directory of Open Access Journals (Sweden)

    Deng-hong CHEN

    2011-06-01

    Full Text Available There existed some limitations when analyzing the anti-sliding seismic stability of dam-foundation system by traditional pseudo-static method and response spectrum method. The dynamic strength reduction method was used to study on the deep anti-sliding stability of a high gravity dam considering complex dam foundation under strong earthquake-induced ground action. The static analysis was firstly carried out by reducing the shear strength parameters of the dam foundation’s rock mass with equal proportion. Then, the time-history seismic analysis was carried out based on the static analysis. It was proposed as one of dynamic instability criterions that the peak values of the dynamic displacements and plastic strain energy change suddenly with increasing strength reduction coefficient. The elasto-plastic behavior of the dam foundation was idealized using Drucker–Prager yield criterion based on associated flow rule assumption. Through the static, dynamic strength reduction analysis and dynamic linear elastic analysis of the overflow dam monolith of a high gravity dam, the results’ reliability of elastic-plastic time history analysis was confirmed. The results also showed that the rock mass strength of the high gravity dam foundation has higher strength reserve coefficient. The instability criterions of dynamic strength reduction method proposed were feasible. Although the static anti-slide analysis methods and standards of gravity dam based on the numerical methods are being discussed at present, the dynamic calculation method and instability criterions proposed in this paper would provide some meaningful suggestions for the dynamic analysis of the similar projects.

  9. Optimizing the dammed: water supply losses and fish habitat gains from dam removal in California.

    Science.gov (United States)

    Null, Sarah E; Medellín-Azuara, Josué; Escriva-Bou, Alvar; Lent, Michelle; Lund, Jay R

    2014-04-01

    Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime and degrading aquatic and riparian habitat. Restoring some rivers reaches to free-flowing conditions may restore substantial environmental benefits, but at some economic cost. This study uses a systems analysis approach to preliminarily evaluate removing rim dams in California's Central Valley to highlight promising habitat and unpromising economic use tradeoffs for water supply and hydropower. CALVIN, an economic-engineering optimization model, is used to evaluate water storage and scarcity from removing dams. A warm and dry climate model for a 30-year period centered at 2085, and a population growth scenario for year 2050 water demands represent future conditions. Tradeoffs between hydropower generation and water scarcity to urban, agricultural, and instream flow requirements were compared with additional river kilometers of habitat accessible to anadromous fish species following dam removal. Results show that existing infrastructure is most beneficial if operated as a system (ignoring many current institutional constraints). Removing all rim dams is not beneficial for California, but a subset of existing dams are potentially promising candidates for removal from an optimized water supply and free-flowing river perspective. Removing individual dams decreases statewide delivered water by 0-2282 million cubic meters and provides access to 0 to 3200 km of salmonid habitat upstream of dams. The method described here can help prioritize dam removal, although more detailed, project-specific studies also are needed. Similarly, improving environmental protection can come at substantially lower economic cost, when evaluated and operated as a system.

  10. Predicting Water Levels at Kainji Dam Using Artificial Neural Networks

    African Journals Online (AJOL)

    Predicting Water Levels at Kainji Dam Using Artificial Neural Networks. ... The aim of this study is to develop artificial neural network models for predicting water levels at Kainji Dam, which supplies water to Nigeria's largest ... Article Metrics.

  11. Inventory of Dams in the State of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Permitted dams in Iowa and associated attributes, as recorded by the Floodplain Section of the DNR. The dams regulated are those with the parameters listed below: a....

  12. National Inventory of Dams Coastal California Extract 2010

    Data.gov (United States)

    California Department of Resources — The National Inventory of Dams (NID) is a congressionally authorized database, which documents dams in the U.S. and its territories. The NID was most recently...

  13. Research review of the cement sand and gravel (CSG) dam

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The cement sand and gravel (CSG) dam is a new style of dam that owes the advantages both of the concrete faced rock-fill dam (CRFD) and roller compacted concrete (RCC) gravity dam,because of which it has attracted much attention of experts home and abroad.At present,some researches on physic-mechanical property of CSG material and work behavior of CSG dam have been done.This paper introduces the development and characteristics of CSG dam systematically,and summarizes the progress of the study on basic tests,constitutive relation of CSG material and numerical analysis of CSG dam,in addition,indicates research and application aspect of the dam.

  14. Computational Aspects of Dam Risk Analysis: Findings and Challenges

    Directory of Open Access Journals (Sweden)

    Ignacio Escuder-Bueno

    2016-09-01

    Full Text Available In recent years, risk analysis techniques have proved to be a useful tool to inform dam safety management. This paper summarizes the outcomes of three themes related to dam risk analysis discussed in the Benchmark Workshops organized by the International Commission on Large Dams Technical Committee on “Computational Aspects of Analysis and Design of Dams.” In the 2011 Benchmark Workshop, estimation of the probability of failure of a gravity dam for the sliding failure mode was discussed. Next, in 2013, the discussion focused on the computational challenges of the estimation of consequences in dam risk analysis. Finally, in 2015, the probability of sliding and overtopping in an embankment was analyzed. These Benchmark Workshops have allowed a complete review of numerical aspects for dam risk analysis, showing that risk analysis methods are a very useful tool to analyze the risk of dam systems, including downstream consequence assessments and the uncertainty of structural models.

  15. Harvesting river water through small dams promote positive environmental impact.

    Science.gov (United States)

    Agoramoorthy, Govindasamy; Chaudhary, Sunita; Chinnasamy, Pennan; Hsu, Minna J

    2016-11-01

    While deliberations relating to negative consequences of large dams on the environment continue to dominate world attention, positive benefits provided by small dams, also known as check dams, go unobserved. Besides, little is known about the potential of check dams in mitigating global warming impacts due to less data availability. Small dams are usually commissioned to private contractors who do not have clear mandate from their employers to post their work online for public scrutiny. As a result, statistics on the design, cost, and materials used to build check dams are not available in public domain. However, this review paper presents data for the first time on the often ignored potential of check dams mitigating climate-induced hydrological threats. We hope that the scientific analysis presented in this paper will promote further research on check dams worldwide to better comprehend their eco-friendly significance serving society.

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

    Science.gov (United States)

    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

  17. Lac Courte Oreilles Hydro Dam Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Jason [Lac Courte Oreilles, Hayward, WI (United States); Meyers, Amy [Kiser Hydro, LLC, Norway, MI (United States)

    2014-12-31

    The main objective of this project was to investigate upgrading the existing hydro power generating system at the Winter Dam. The tribe would like to produce more energy and receive a fair market power purchase agreement so the dam is no longer a drain on our budget but a contributor to our economy. We contracted Kiser Hydro, LLC Engineering for this project and received an engineering report that includes options for producing more energy with cost effective upgrades to the existing turbines. Included in this project was a negotiation of energy price sales negotiations.

  18. Novel monitoring protocol for the Monte Cotugno Dam (Southern Italy) healthiness

    Science.gov (United States)

    Soldovieri, Francesco; Loperte, Antonio

    2015-04-01

    This work is concerned with the application of an integrated approach based on a non-invasive geophysical technique, as the Electrical Resistivity Tomography (ERT) and geotechnical and visual inspections for the monitoring of the Monte Cotugno dam, the largest rock fill dam in Europe. Monte Cotugno dam is located on the Sinni river (Basilicata District, South Italy) and represents the nodal point of the whole hydraulic system on the Ionic side of Italy. In fact, the dam allows harnessing of the Sinni river water for agricultural, industrial, drinking and domestic purposes. The dam consists of a central core in sandy silt and of gravelly-sandy shoulders; its water tightness is ensured by a bituminous conglomerate facing on the upstream side, welded at the bottom to the foundation sealing system. The latter is about 1,900m long and consist of a massive concrete cut-off wall based on the marly-clay formation, 300m long on the right and 600 m long on the left side. On the valley bottom, dam is made up of a reinforced concrete cut-off wall that is inserted in the marly-clay formation and is surmounted by an inspection and percolation water collection tunnel. The watertight face consists of different layers and the shallowest layers have been affected by incipient small detachments due to thermal solicitations; These detachments affect the structural behavior of the dam, since they are way for water infiltration in the dam. For this reason, on 2010 dam's owner decided to activate an integrated geophysical survey based on the integrated use of Infrared Termography, ERT and Ground Penetrating Radar, with the aim to identify and evaluate the potential loss of water through small cracks in the bituminous concrete dam [1]. Following the results achieved by this non-invasive integrated approach, it was decided to activate a long term monitoring based on periodic ERT surveys. In particular, ERT surveys were carried out for two years at two specific times of the year, in order

  19. Research on Dam Perspective Based on Numerical Solution

    Institute of Scientific and Technical Information of China (English)

    WANGZi-ru; ZHOUHui-cheng; LIMing-qiu

    2005-01-01

    The numerical solution of dam toe line is solved based on the dam data and topographic map of dam located. The display of dam perspective is also realized by programming of using VC++ and OpenGL. The research results above provide the foundation of construction design, construction lofting and information inquiry, which avoids the drawbacks of only using blueprints to do the same work in the past. The method used is useful in practical engineering.

  20. Interferometric direct imaging properties of a BIGRE-DAM device in laboratory

    Science.gov (United States)

    Patru, Fabien; Antichi, Jacopo; Rabou, Patrick; Giro, Enrico; Farinato, Jacopo; Gratton, Raffaele; Vassallo, Daniele; Verinaud, Christophe; Mourard, Denis; Girard, Julien

    2016-08-01

    DAM (Discretized Aperture Mapping) is an original optical concept able to improve the performance in high angular resolution and high contrast imaging by the present class of large telescopes equipped with adaptive optics. By discretizing the entrance pupil of a large telescope into an array of many coherent sub-apertures, DAM provides unique imaging and filtering properties by means of spatial filtering and interferometric techniques. DAM can be achieved by means of single-mode fibers, integrated optic waveguides, pinholes, or simply with an innovative BIGRE optical device. BIGRE is formed of an afocal double micro-lenses array. In addition to the pupil discretization process by spatial filtering, BIGRE can also provide two other optical processes: the pupil densification or the pupil dilution. DAD (Discretized Aperture Densification) increase the sub-aperture sizes and is suitable to a hypertelescope, whereas DADI (Discretized Aperture Dilution Interferometry) reduces the sub-aperture sizes and turns a large telescope into a Fizeau interferometer. This paper deals with the first in-lab experiment at visible wavelength of BIGRE devices for the three configurations above. We study the point spread function (PSF) when observing a point-like object located either on-axis or at various off-axis positions across the field of view. Both interferometric and diffractive effects are described. The experimental measurements are in good agreement with the BIGRE theory. It results that BIGRE fulfils the requirements to carry out spatially filtered pupil discretization (DAM), with possible densification (DAD) or dilution (DADI).

  1. SEFIDROOD RIVER SUB-WATERSHED-DAM-ESTUARY AND DEGRADATION MODEL: A HOLISTIC APPROACH IN IRAN

    Institute of Scientific and Technical Information of China (English)

    Forood AZARI DEHKORDI; Majid F MAKHDOUM; Nobukazu NAKAGOSHI

    2003-01-01

    The major concern of this article is to address the shortcoming and outgoing effects of the human activities on the landscape patterns and their consequences in the Sefidrood River watershed in Iran. A flow of data includes three inputs; each of them belongs to one part of three zones of a fluvial system. The three parts of the Sefidrood River fluvial system include Zone 1, a sub-watershed as degradation modeling site, Zone 2, Sefidrood Dam as dam site, and Zone 3, 17km away from the Sefidrood River path to the Caspian Sea as ending point site. The degradation model in the Zone 1 provides a suitable mean for decision support system to decrease the human impacts on each small district. The maximum number for degradation coefficient belongs to the small district with the highest physiographic density, relatively cumulative activities, and a lower figure for the habitat vulnerability. The human degradation impact were not limited to the upstream. The investigation to the Sefldrood Dam and ending point of the Sefldrood River depicts that sedimentation continues as a significant visual impact in the Sefidrood Dam reservoir and the estuary.

  2. Investigation on the Causes of Cracking in Earth Dams (Case study: Mahmood-Abad Earth Dam

    Directory of Open Access Journals (Sweden)

    H. Rahimi

    2016-09-01

    Full Text Available Introduction: Cracking of earth dams is a one of the main threat causes of stability of embankment dams. In this research by modeling of the behavior of an embankment dam and employing conditions of the earthquake, the reasons of cracking were inspected using by modeling of earth dam behavior. Based on the literature, one of the main causes of dam failures is sliding and cracking of the dam structure during earthquake. Localized liquefaction of foundation soils was one of the causes of the observed post-earthquake distress within these dams. Material and Methods: In order to study the causes and the results of crack on earth dams, Mahmoodabad earthen dam with a height of 19 m, is located in Zanjan province, northwest of Iran, which suffered a longitudinal crack on the crest and slight sliding of the upstream slope due to 2001 Avaj earthquake was studied. This dam has faced earthquake two times with an interval of two years. During the first earthquake with the magnitude about 6.6 in Richter scale small longitudinal cracks had created on the crest. The developed cracks had been repaired by injecting the cement and then has been hidden by passing the time. After the second earthquake with the magnitude about 6.5 in Richter scale the hidden cracks had been appeared again and the slight movement of the upper slopes of dam reported. Based on the site investigation and documented information about dam, including maps and parameter data, the behavior of the dam has modeled by using Plaxis as a finite element model. In order to check the accuracy of the design of dam, the stability analysis has been conducted using by Xslope as a limit equilibrium model. The foundation conditions and the Geotechnical properties of the layer beneath the dam has been inspected by open excavation. Results and Discussion: Underground investigation about Geotechnical properties of dam foundation has showed that there is a thin sandy layer confined in alluvium material of the

  3. Major dams of the United States, Geographic NAD83, USGS (2006) [dams00x020_USGS_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — This map layer portrays major dams of the United States, including Puerto Rico and the U.S. Virgin Islands. The map layer was created by extracting dams 50 feet or...

  4. 43 CFR 418.18 - Diversions at Derby Dam.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Diversions at Derby Dam. 418.18 Section... Operations and Management § 418.18 Diversions at Derby Dam. (a) Diversions of Truckee River water at Derby Dam must be managed to maintain minimum terminal flow to Lahontan Reservoir or the Carson River...

  5. 25 CFR 173.16 - Reserved area, Coolidge Dam.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Reserved area, Coolidge Dam. 173.16 Section 173.16... area, Coolidge Dam. No permit for any commercial business or other activity (except boating concessions...-fourths of a mile from the center of the Coolidge Dam, Arizona....

  6. 21 CFR 872.6300 - Rubber dam and accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rubber dam and accessories. 872.6300 Section 872...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6300 Rubber dam and accessories. (a) Identification. A rubber dam and accessories is a device composed of a thin sheet of latex with a hole in...

  7. SEISMIC RESPONSE OF DAM WITH SOIL-STRUCTURE INTERACTION.

    Science.gov (United States)

    Bycroft, G.N.; Mork, P.N.

    1987-01-01

    An analytical solution to the response of a long trapezoidal-section dam on a foundation consisting of an elastic half-space and subjected to simulated earthquake motion is developed. An optimum seismic design is achieved when the cross section of the dam is triangular. The effect of soil structure interaction is to lower the strain occurring in the dam.

  8. Immediate changes in stream channel geomorphology, aquatic habitat, and fish assemblages following dam removal in a small upland catchment

    Science.gov (United States)

    Magilligan, F. J.; Nislow, K. H.; Kynard, B. E.; Hackman, A. M.

    2016-01-01

    downstream reach. Post-removal, but pre-flood, bed surveys indicate 2 m of incision had migrated 25 m upstream of the former reservoir before encountering the exhumed dam, which now acts as the new grade control, limiting progressive headcutting. Approximately 1000 m3 of sediment was evacuated in the first year, with 67% of the volume occurring by pre-flood, process-driven (e.g., changes in base level) controls. The combination of changes in channel-bed sedimentology, the occurrence of a large magnitude flood, and the emergence of the new crib dam that is a likely barrier to fish movement was associated with major reductions in abundance and richness in sites downstream and immediately upstream adjacent to the former dam in post-removal sampling. At the same time, we documented the presence of four species of fish, including sea lamprey, which were not present above the dam prior to removal, indicating that upstream passage has been achieved; and we also documented lamprey spawning activity at sites immediately below the dam, which had previously been unsuitable owing to an excessively coarse and armored riverbed. Our results point to the importance of interactions between dam removal and flood disturbance effects, with important implications for short- and long-term monitoring and assessment of dam impacts to river systems.

  9. The expected collapse of a large dam Saddam Dam in Iraq; Un grand barrage a haut risque Saddam Dam en Irak

    Energy Technology Data Exchange (ETDEWEB)

    Mesny, M. [Conseil general du genie rural, des eaux et des forets, 75 - Paris (France)

    2004-07-01

    The Saddam dam is a very large dam in Iraq on the Tigris River, 80 kilometres upstream from the city of Mosul. It is a fill dam with a clayey silt core. The height of the dam is 120 meters and the capacity of the reservoir is 11 billions m3. But this dam has been built on foundations of gypsum that is a rock soluble in water. The impounding of the reservoir in 1986 has shown that, in spite of the grout curtain, substantial seepage has occurred (up to 1.4 m{sup 3}/s), as well as the dissolution of minerals from foundations (up to 80 tons per day). The substantial increase in permeability and seepage through the dam foundations results in a severe concern about the stability of the dam. The program of injection has been stopped in 1991, due to the circumstances. So there is a real risk that this dam would collapse through a quickly developing leak in the dike, resulting in the devastation of the rich agricultural valley of the Tigris River and in potential human losses at Mosul. A 10 to 20-meter high submersion wave would reach this town 3 to 4 hours after the collapse of the dam. An international action is urgently required to check the conditions of the dam and to propose remedial solutions, which may be a 120-meter deep concrete wall down to the calcareous floor existing below the soluble layers of the foundations. (author)

  10. Dams life. Dams in operation; La vie des barrages. Barrages en exploitation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This paper summarizes the conclusions of the annual inspections of French dams in operation (fissures, water oozing, concrete swelling etc..). Only the observations which require a special attention are reported. (J.S.)

  11. DAM-LAKEFRONT PLAZA: Revitalization of an Agriculture Reservoir Dam in Kashar-Tirana/Albania

    Directory of Open Access Journals (Sweden)

    Valbona Koçi

    2014-12-01

    Full Text Available The Dam-Lakefront Plaza in Kashar-Tirana/Albania is a research project that proposes not only the re-consideration and reinforcement of the artificial Reservoirs Dams built during Socialism in Albania, but envisions the maintenance of dams and revitalization of the lakeside area promoting the public-private collaboration. In addition, it envisions the generation of qualitative and lively public spaces in sub-urban areas as well. Admitting the artificial lakes as specific nodes of man-made infrastructure in the landscape, and consequently the dams (together with the drainage channels as important hydrotechnic elements of the flood protection infrastructure, this research intends to elaborate on one type of landscape infrastructure - the vertical screens, offering a mediation between the natural and built landscape.

  12. 7 CFR 1724.55 - Dam safety.

    Science.gov (United States)

    2010-01-01

    ... result from encountering unanticipated or unusual conditions during construction. (5) The independent review of construction shall include: (i) Foundation preparation and treatment. When the foundation has... construction. The reviewer must have demonstrated experience in the design and construction of dams of...

  13. Aquifer performance under the Mactaquac Dam

    Energy Technology Data Exchange (ETDEWEB)

    Tawil, A.H. [Acres International, Niagara Falls, ON (Canada); Harriman, F.B. [New Brunswick Power, Fredericton, NB (Canada)

    2001-10-01

    The highest dam in the whole of the Maritimes and New Brunswick in particular is the Mactaquac Dam, with a height of 58 m above the foundation. It forms an integral part of the Mactaquac Hydroelectric Development and the construction of the dam was completed in 1967. Composed of a central core of clay till and external shells of rockfill, it is a zoned embankment. The high artesian pressure rising 6 m above the Saint John River dominates, and the foundation under the dam is composed of a stratum of stiff glacial till underlain with a thick, water bearing aquifer. The aquifer needed to be depressurized during the construction phase and in the long term, and special measures were required to accomplish this. Measurements obtained over a period exceeding 30 years were used to describe the performance of the aquifer, which is discussed in this presentation. A continuous reduction in the yield from the six permanent relief wells in the aquifer was indicated by the instrumentation data. The outflow from the wells diminished by two-thirds over the thirty-four years since first filling the reservoir. The piezometric pressure in the aquifer remained constant over the same period. The sparse results of a two-hour pump test had formed the basis for the design decision not to install a costly foundation seepage cut-off to bedrock, as the conclusions drawn from the pump test were that the aquifer was hydrogeologically confined. 3 refs., 4 tabs., 9 figs.

  14. Increasing dam safety with multi beam sonar

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, M. [SwedPower AB, Stockholm (Sweden); Cederstrom, M.O. [Vattenfall AB, Stockholm (Sweden); Deborg, J. [SwedPower AB, Alvkarleby (Sweden)

    2004-09-01

    Multi-beam sonar technology has been introduced to Vattenfall's dam safety program. Vattenfall is the major energy producer in Sweden and the third largest utility in Europe. Embankment dams are subject to processes such as erosion, settlement and sinkholes. The new portable multi-beam echo sounder system is an important tool to detect minor damages and to intervene before they evolve into expensive or hazardous situations. A first survey of the upstream slope of a rockfill dam with this method provides a topographic map indicating the location of anomalies such as internal erosion or piping. Multi-beam sonar works by combining GPS-RTK positioning, gyro motion sensing, a multi-beam sonar and 3-dimensional digital terrain programs. Vattenfall is using the system to verify and monitor all high hazard rockfill dams in Sweden to ensure long-term stability. The data will be stored as a fingerprint for comparison with future surveys in 15 to 20 years as part of routine safety evaluation. This new technology can also be used to survey breakwaters, erosion of rivers and to locate submerged debris in harbours. 6 figs.

  15. A Final Test for the Big Dam

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ The water level at the Three Gorges Dam,the world's largest water control and utilization project,reached its designed highest mark on October 26,which will enable the project to fulfill its functions of flood control,power generation,navigation and water diversion.

  16. Will We. . .? Thai Dam Resource Book.

    Science.gov (United States)

    Murphy, Richard, Ed.; And Others

    This resource book is intended as an aid to persons working with Thai Dam refugees. To help the language teacher, some differences between Lao and English are discussed, specifically tonal inflections, positioning, declension of pronouns, conjugation of verbs, interrogatives, classifiers and predicate adjectives. An outline of cultural differences…

  17. Resilience scales of a dammed tropical river

    Science.gov (United States)

    Calamita, Elisa; Schmid, Martin; Wehrli, Bernhard

    2017-04-01

    Artificial river impoundments disrupt the seasonality and dynamics of thermal, chemical, morphological and ecological regimes in river systems. These alterations affect the aquatic ecosystems in space and time and specifically modify the seasonality and the longitudinal gradients of important biogeochemical processes. Resilience of river systems to anthropogenic stressors enables their recovery along the flow path; however little is known about the longitudinal distance that rivers need to partially restore their physical, chemical and biological integrity. In this study, the concept of a "resilience scale" will be explored for different water quality parameters downstream of Kariba dam, the largest artificial lake in the Zambezi basin (South-East Africa). The goal of this project is to develop a modelling framework to investigate and quantify the impact of large dams on downstream water quality in tropical context. In particular, we aim to assess the degree of reversibility of the main downstream alterations (temperature, oxygen, nutrients) and consequently the quantification of their longitudinal extent. Coupling in-situ measurements with hydraulic and hydrological parameters such as travel times, will allow us to define a physically-based parametrization of the different resilience scales for tropical rivers. The results will be used for improving future dam management at the local scale and assessing the ecological impact of planned dams at the catchment scale.

  18. Fish reproductive guilds downstream of dams.

    Science.gov (United States)

    Vasconcelos, L P; Alves, D C; Gomes, L C

    2014-11-01

    Fish reproductive guilds were used to evaluate the responses of species with different reproductive strategies during two different periods of post-dam construction. The data used for the comparisons were collected in the upper Paraná River floodplain (Brazil), downstream of the Porto Primavera dam, 2 and 10 years after impoundment. The abundance (catch per unit effort, CPUE), species richness, evenness and structure of communities, all within reproductive guilds, were used to test the hypothesis that these metrics vary spatially and temporally. The influence of damming on species structure and the diversity of fish reproductive guilds varied spatiotemporally, and species with opportunistic reproductive strategies tended to be less affected. Conversely, long-distance migratory species responded more markedly to spatiotemporal variations, indicating that the ecosystem dynamics exert greater effects on populations of these species. Thus, the effects of a dam, even if attenuated, may extend over several years, especially downstream. This finding emphasizes the importance of maintaining large undammed tributaries downstream of reservoirs.

  19. Modelling approach for gravity dam break analysis

    Directory of Open Access Journals (Sweden)

    Boussekine Mourad

    2016-09-01

    Full Text Available The construction of dams in rivers can provide considerable benefits such as the supply of drinking and irrigation water; however the consequences which would result in the event of their failure could be catastrophic. They vary dramatically depending on the extent of the inundation area, the size of the population at risk.

  20. Experimental research on the dam-break mechanisms of the Jiadanwan landslide dam triggered by the Wenchuan earthquake in China.

    Science.gov (United States)

    Xu, Fu-gang; Yang, Xing-guo; Zhou, Jia-wen; Hao, Ming-hui

    2013-01-01

    Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation.

  1. Expectations of immortality: dam safety management into the next millennium

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, M.D. [Tonkin and Taylor International Ltd., Auckland, (New Zealand)

    1999-07-01

    Topics concerning the problems associated with older and aging dams are considered including: what can be done to extent the lifetime of an old dam, the decision to decommission a dam based on a value judgment that the risk of maintaining the dam is too great for society's acceptance, the possibility of change in the level of risk tolerance with time in a technological environment, traditional surveillance methods used by dam owners in the Y2K situation, and the unreality of dam immortality. Trends and means for preserving older dams for their owner's purposes are outlined, as well as their lifetime compared to that of the downstream systems they serve. Despite the fact that we live in a throwaway society, dam owners cannot just leave their dam asset when they are through with using it. Someone has to maintain the dam, or ensure that it is safely decommissioned when the owner is finished with it. On a worldwide scale the available pool of experienced dam engineers is shrinking. This problem needs to be addressed by a shift towards operating and dam safety management skills based on a firm awareness of dam design principles. A shift in society's expectations has occurred such that dam designers and owners must now recognize the impact a dam can have both on its natural and social environments. Because of the increasing emphasis on paying attention to the impacts of people's activities on the planet, engineers more than anyone else must have a significant influence in that direction. 9 refs.

  2. Socioeconomic and Institutional Dimensions of Dam Removals: The Wisconsin Experience

    Science.gov (United States)

    Born; Genskow; Filbert; Hernandez-Mora; Keefer; White

    1998-05-01

    / There are tens of thousands of small dams in the United States; many of these aging structures are deteriorating. Governments and dam owners face decisions regarding repair or removal of these structures. Along with the many benefits society derives from dams and their impoundments, numerous recent ecological studies are revealing the extensive alteration and degradation of river ecosystems by dams. Dam removal-a principal restoration strategy-is an infrequent event. The major reasons for removal have been public safety and the high costs associated with repair; the goal of river ecosystem restoration now warrants greater attention. Substantial study is being given to the environmental aspects of dams and dam removals, but very little attention has been given to the socioeconomic and institutional dimensions associated with the removal of dams, although these factors play a significant role in the removal decision-making process. Based on a case study of dam removals in Wisconsin-where more than 30 of the state's 3600 small dams have been removed in the past few decades-legal, financial, and socioeconomic issues associated with dam removal are documented and assessed. Dam removal has been complex and contentious, with limited community-based support for removal and loss of the impounded waters. In cases examined here, the estimated costs of repairing a dam averaged more than three times the cost of removal. The availability of governmental financing has been a key determinant in removal decisions. Watershed-scale ecological considerations are not major factors for most local interests. As watershed management and restoration increasingly include dam removal options as part of an integrated strategy, more attention will need to be focused on socioeconomic factors and stakeholder perspectives-variables that strongly influence the viability of this management alternative.KEY WORDS: Dam removal; River restoration; Institutions; Stakeholders

  3. River restoration by dam removal: Enhancing connectivity at watershed scales

    Directory of Open Access Journals (Sweden)

    F.J. Magilligan

    2016-05-01

    Full Text Available Abstract The prolonged history of industrialization, flood control, and hydropower production has led to the construction of 80,000 dams across the U.S. generating significant hydrologic, ecological, and social adjustments. With the increased ecological attention on re-establishing riverine connectivity, dam removal is becoming an important part of large-scale river restoration nationally, especially in New England, due to its early European settlement and history of waterpower-based industry. To capture the broader dimensions of dam removal, we constructed a GIS database of all inventoried dams in New England irrespective of size and reservoir volume to document the magnitude of fragmentation. We compared the characteristics of these existing dams to the attributes of all removed dams over the last ∼25 years. Our results reveal that the National Inventory of Dams significantly underestimates the actual number of dams (4,000 compared to >14,000. To combat the effects of these ecological barriers, dam removal in New England has been robust with 127 dams having been removed between ca. 1990–2013. These removed dams range in size, with the largest number (30% ranging between 2–4 m high, but 22% of the removed dams were between 4–6 m. They are not isolated to small drainage basins: most drained watersheds between 100–1,000 km2. Regionally, dam removal has re-connected ∼3% (3,770 river km of the regional river network although primarily through a few select dams where abundant barrier-free river lengths occur, suggesting that a more strategic removal approach has the opportunity to enhance the magnitude and rate of river re-connection. Given the regional-scale restoration of forest cover and water quality over the past century, dam removal offers a significant opportunity to capitalize on these efforts, providing watershed scale restoration and enhancing watershed resilience in the face of significant regional and global anthropogenic

  4. RESEARCH ON SEEPAGE MONITORING MODEL OF EARTH-ROCK DAM

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    With the characteristics of seepage flow in earth-rock dams, a seepage monitoring model was established based on the finite element method for 3-D seepage flow together with observed data and was used to analyze and monitor the seepage of dams. In order to find out and monitor the seepage status of the whole dam, the separation of seepage amount for dam body, dam foundation and side banks was made theoretically by using the model. Practical example shows that the accuracy of computed results is satisfactory and the separation results are more objective.

  5. Determination of cadmium and copper in fish samples from Sir and Menzelet Dam Lake Kahramanmaraş, Turkey.

    Science.gov (United States)

    Erdogrul, Ozlem; Ateş, D Ayfer

    2006-06-01

    The cadmium and copper levels were determined in the total of 126 fish samples which belongs to five fish species collected from Sir and Menzelet Dam Lakes in Kahramanmaraş Province by Atomic Absorption Spectrophotometer. The concentrations of heavy metals were expressed as ppm wet weight of tissue. The mean levels of cadmium and copper in muscle, liver and gill tissues of Cyprinus carpiofrom the Menzelet Dam were found as 0.27, 0.91, 1.49 and 0.94, 1.2, 1.05, respectively. The mean levels of Cd in the muscle tissues of Leuciscus cephalusfrom the Menzelet Dam were found 0.32 ppm, Cd wasn't found in tissues of liver and gill. The mean levels of Cu in the muscle, liver and gill tissues were found as 3.17 ppm, 1.19 ppm, 0.96 ppm, respectively. The mean levels of the Cd and Cu in muscle and gill tissues of Acanthobrama marmid from the Sir Dam were found as 1.28, 2.64 and 0.72, 0.08, respectively. The levels of the Cd and Cu in muscle tissues of Cyprinus carpiofrom the Sir Dam were found 0.87 and 0.02 ppm, respectively. The mean levels of the Cd and Cu in the muscle and gill tissues of Chondrostoma regium from the Sir Dam were found to be 0.80, 2.62 and 0.67, 1.34 ppm, respectively. The mean levels of the Cd in the muscle tissues of the Silurus glanis was found as 0.60 ppm. In the muscle of the Silurus glanis from the Sir Dam, Cu was not found. The Sir Dam is more polluted than the Menzelet Dam from the point of Cd but less polluted than the Menzelet Dam From the point of Cu. A relationship was determined between species and their habitating region in terms of the levels reflected metal residues. In this study it was emphasized that the amounts of Cd and Cu in the samples were low, however, seas, lakes, rivers, soil, air and consumed foods etc. has to be controlled routinely.

  6. Mining dams safety regulations : where does Canada stand?

    Energy Technology Data Exchange (ETDEWEB)

    Priscu, C. [AMEC, Winnipeg, MB (Canada); Small, A. [AMEC Earth and Environmental Ltd., Fredericton, NB (Canada); Lupo, J. [AMEC, Englewood, CO (United States); Diaz, M. [AMEC, Ashford, Kent (United Kingdom); Davies, M. [AMEC, Vancouver, BC (Canada); Musse, M. [AMEC, Santiago (Chile)

    2009-07-01

    While many jurisdictions in Canada use the Canadian Dam Association (CDA) dam safety guidelines, their applicability to the safety of mining dams is limited. Mining dams are some of the largest containment structures in the world, and impound millions of cubic meters of mine process residues in both solid and liquid form. This study presented a review of dam safety regulatory frameworks for mining dams located in various countries. The aim of the study was to compare the Canadian framework with various dam safety legislations in order to evaluate Canada's current status and recommend best practices in dam safety regulations. The study reviewed incremental consequence classifications; best practices in operation, surveillance and maintenance manuals and procedures; emergency preparedness plans; and dam safety inspections. The study showed that Canada has limited documentation regulating the safe management of tailings facilities, and does not have an all-encompassing national guideline for mining dams. It was concluded that an incremental consequence classification (ICC) system should be developed specifically for mining dams. 12 refs.

  7. Seismic failure modes and seismic safety of Hardfill dam

    Directory of Open Access Journals (Sweden)

    Kun XIONG

    2013-04-01

    Full Text Available Based on microscopic damage theory and the finite element method, and using the Weibull distribution to characterize the random distribution of the mechanical properties of materials, the seismic response of a typical Hardfill dam was analyzed through numerical simulation during the earthquakes with intensities of 8 degrees and even greater. The seismic failure modes and failure mechanism of the dam were explored as well. Numerical results show that the Hardfill dam remains at a low stress level and undamaged or slightly damaged during an earthquake with an intensity of 8 degrees. During overload earthquakes, tensile cracks occur at the dam surfaces and extend to inside the dam body, and the upstream dam body experiences more serious damage than the downstream dam body. Therefore, under the seismic conditions, the failure pattern of the Hardfill dam is the tensile fracture of the upstream regions and the dam toe. Compared with traditional gravity dams, Hardfill dams have better seismic performance and greater seismic safety.

  8. Dam failure analysis for the Lago El Guineo Dam, Orocovis, Puerto Rico

    Science.gov (United States)

    Gómez-Fragoso, Julieta; Heriberto Torres-Sierra,

    2016-08-09

    The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed hydrologic and hydraulic analyses to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago El Guineo Dam. The Lago El Guineo Dam is within the headwaters of the Río Grande de Manatí and impounds a drainage area of about 4.25 square kilometers.The hydrologic assessment was designed to determine the outflow hydrographs and peak discharges for Lago El Guineo and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation event, (2) a 24-hour probable maximum precipitation event, and (3) a 24-hour, 100-year recurrence rainfall event. The hydraulic study simulated a dam failure of Lago El Guineo Dam using flood hydrographs generated from the hydrologic study. The simulated dam failure generated a hydrograph that was routed downstream from Lago El Guineo Dam through the lower reaches of the Río Toro Negro and the Río Grande de Manatí to determine water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” conditions. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC–HMS) and Hydrologic Engineering Center’s River Analysis System (HEC–RAS) computer programs, developed by the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was completed using the unsteady flow module available in the HEC–RAS model.Above the Lago El Guineo Dam, the simulated inflow peak discharges from HEC–HMS resulted in about 550 and 414 cubic meters per second for the 6- and 24-hour probable maximum precipitation events, respectively. The 24-hour, 100-year recurrence storm simulation resulted in a peak discharge of about 216 cubic meters per second. For the hydrologic analysis, no dam failure conditions are

  9. Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management

    Science.gov (United States)

    Buccola, Norman L.; Rounds, Stewart A.; Sullivan, Annett B.; Risley, John C.

    2012-01-01

    Detroit Dam was constructed in 1953 on the North Santiam River in western Oregon and resulted in the formation of Detroit Lake. With a full-pool storage volume of 455,100 acre-feet and a dam height of 463 feet, Detroit Lake is one of the largest and most important reservoirs in the Willamette River basin in terms of power generation, recreation, and water storage and releases. The U.S. Army Corps of Engineers operates Detroit Dam as part of a system of 13 reservoirs in the Willamette Project to meet multiple goals, which include flood-damage protection, power generation, downstream navigation, recreation, and irrigation. A distinct cycle in water temperature occurs in Detroit Lake as spring and summer heating through solar radiation creates a warm layer of water near the surface and isolates cold water below. Controlling the temperature of releases from Detroit Dam, therefore, is highly dependent on the location, characteristics, and usage of the dam's outlet structures. Prior to operational changes in 2007, Detroit Dam had a well-documented effect on downstream water temperature that was problematic for endangered salmonid fish species, releasing water that was too cold in midsummer and too warm in autumn. This unnatural seasonal temperature pattern caused problems in the timing of fish migration, spawning, and emergence. In this study, an existing calibrated 2-dimensional hydrodynamic water-quality model [CE-QUAL-W2] of Detroit Lake was used to determine how changes in dam operation or changes to the structural release points of Detroit Dam might affect downstream water temperatures under a range of historical hydrologic and meteorological conditions. The results from a subset of the Detroit Lake model scenarios then were used as forcing conditions for downstream CE-QUAL-W2 models of Big Cliff Reservoir (the small reregulating reservoir just downstream of Detroit Dam) and the North Santiam and Santiam Rivers. Many combinations of environmental, operational, and

  10. Gabcikovo dam and Liptovska Mara dam - statistical analysis of measurement data

    Science.gov (United States)

    Hakac, J.; Sabo, M.

    2012-04-01

    Introduction: Water level in the observation wells is measured regularly and one of the reasons is evaluation of the safety of the water constructions. In this paper we are exploring the reliability of the measuring devices that are responsible for evaluation of the safety of the two largest and the most important dams in Slovakia. We test ability of selected statistical methods to detect early inaccuracies of measuring devices and thus improve the evaluation of the safety of the water constructions. As a follow-up study, we used the time series model (Neural network) to predict water levels in the observation wells that were considered to be without defects. Neural Network is also able to show dynamics of the filtration stability of the observational well. Methods: On the Liptovska Mara dam weekly data was used as a monitoring tool. On the Gabcikovo dam five minute time series of the measurements of the water level in observation wells around the right lock chamber were used. Data from the measuring devices of the dams were explored with boxplots, correlations, neural network, etc. The mentioned statistical tools analyze time series and detect the errors that measuring devices make when generating data and can be used to predict errors even in real time. In the second step, agreement between predicted data from neural network and measured data in the real time was evaluated. We used grid search for finding the optimal number of neurons and then predicted errors by using this model. The ability of the neural network in evaluation of the sealing of the dilatation joints on the filtration stability in the years 2009 - 2011 is presented. Results: From the 18 selected measuring devices on the Liptovska Mara dam there are only 3 devices which can be considered as reliable. On the Gabcikovo dam, 8 of 9 measuring devices (observation wells around right lock chamber) were considered as a reliable. There was very good agreement between the predicted and measured data at the

  11. Classical Analysis of the van Dam - Veltman Discontinuity

    CERN Document Server

    Carrera, M; Carrera, Matteo; Giulini, Domenico

    2001-01-01

    We consider the classical theory of a gravitational field with spin 2 and non-vanishing (Pauli-Fierz) mass in flat spacetime, coupled to electromagnetism and point particles. We establish the law of light propagation and calculate the amount of deflection in the background of a spherically symmetric gravitational field. As the mass tends to zero, the deflection is shown to converge to 3/4 of the value predicted by the massless theory (linearized General Relativity), even though the spherically symmetric solution of the gravitational field equations has no regular limit. This confirms an old argument of van Dam and Veltman on a purely classical level, but also shows its subtle nature.

  12. Discordance between presumed standard of care and actual clinical practice: the example of rubber dam use during root canal treatment in the National Dental Practice-Based Research Network

    Science.gov (United States)

    Gilbert, Gregg H; Riley, Joseph L; Eleazer, Paul D; Benjamin, Paul L; Funkhouser, Ellen

    2015-01-01

    Objectives Use of a rubber dam during root canal treatment is considered the standard of care because it enhances patient safety and optimises the odds of successful treatment. Nonetheless, not all dentists use a rubber dam, creating disconnect between presumed standard of care and what is actually done in clinical practice. Little is known about dentists’ attitudes towards use of the rubber dam in their practices. The objectives were to: (1) quantify these attitudes and (2) test the hypothesis that specific attitudes are significantly associated with rubber dam use. Setting National Dental Practice-Based Research Network (NationalDentalPBRN.org). Participants 1490 network dentists. Outcome measures Dentists completed a questionnaire about their attitudes towards rubber dam use during root canal treatment. Three attitude scales comprised 33 items that used a 5-point ordinal scale to measure beliefs about effectiveness, inconvenience, ease of placement, comparison to other isolation techniques and patient factors. Factor analysis, cluster analysis and multivariable logistic regression analysed the relationship between attitudes and rubber dam use. Results All items had responses at each point on the 5-point scale, with an overall pattern of substantial variation across dentists. Five attitudinal factors (rubber dam effectiveness; inconvenient/time-consuming; ease of placement; effectiveness compared to Isolite; patient factors) and 4 clusters of practitioners were identified. Each factor and cluster was independently and strongly associated with rubber dam use. Conclusions General dentists have substantial variation in attitudes about rubber dam use. Beliefs that rubber dam use is not effective, inconvenient, time-consuming, not easy to place or affected by patient factors, were independently and significantly associated with lower rubber dam use. These attitudes explain why there is substantial discordance between presumed standard of care and actual practice

  13. Information fusion diagnosis and early-warning method for monitoring the long-term service safety of high dams

    Institute of Scientific and Technical Information of China (English)

    Xing LIU; Zhong-ru WU; Yang YANG; Jiang HU; Bo XU

    2012-01-01

    Analyzing the service behavior of high dams and establishing early-warning systems for them have become increasingly important in ensuring their long-term service.Current analysis methods used to obtain safety monitoring data are suited only to single survey point data.Unreliable or even paradoxical results are inevitably obtained when processing large amounts of monitoring data,thereby causing difficulty in acquiring precise conclusions.Therefore,we have developed a new method based on multi-source information fusion for conducting a comprehensive analysis of prototype monitoring data of high dams.In addition,we propose the use of decision information entropy analysis for building a diagnosis and early-warning system for the long-term service of high dams.Data metrics reduction is achieved using information fusion at the data level.A Bayesian information fusion is then conducted at the decision level to obtain a comprehensive diagnosis.Early-warning outcomes can be released after sorting analysis results from multi-positions in the dam according to importance.A case study indicates that the new method can effectively handle large amounts of monitoring data from numerous survey points.It can likewise obtain precise real-time results and export comprehensive early-warning outcomes from multi-positions of high dams.

  14. Damned If You Do, Dammed If You Don't: Debates on Dam Removal in the Swedish Media

    Directory of Open Access Journals (Sweden)

    Dolly Jørgensen

    2013-03-01

    Full Text Available Dam removal is an increasingly common practice. Dams are removed for various reasons, with safety, economics, and ecosystem restoration being the most common. However, dam removals often cause controversy. Riparian land owners and local communities often have a negative view of removal, and their reasons vary. It may be the loss of recreational benefits such as swimming and boating, loss of cultural and historical context tied to the dam, or fear that removal may have a negative effect on aesthetic values. Because controversies are often picked up by local media, and media in itself is an important channel to build support around a cause, the way in which dam removals are reported and discussed in the media is likely to influence the debate. Here, we examine the ways in which proponents and opponents of dam removal frame the services provided by two contrasting ecosystems, i.e., an existing dam and the potential stream without a dam, by performing a media discourse analysis of the reasons given for removal and the reasons presented for the dam to remain in place. Our source material includes Internet-based newspaper articles and their associated public comments in four dam removal controversies in Sweden. Our analysis indicates that public opposition is not based on knowledge deficiency, where more information will lead to better ecological decision-making, as is sometimes argued in dam removal science; it is instead a case of different understandings and valuation of the environment and the functions it provides.

  15. Dam-breach analysis and flood-inundation mapping for selected dams in Oklahoma City, Oklahoma, and near Atoka, Oklahoma

    Science.gov (United States)

    Shivers, Molly J.; Smith, S. Jerrod; Grout, Trevor S.; Lewis, Jason M.

    2015-01-01

    Dams provide beneficial functions such as flood control, recreation, and storage of water supplies, but they also entail risk; dam breaches and resultant floods can cause substantial property damage and loss of life. The State of Oklahoma requires each owner of a high-hazard dam, which the Federal Emergency Management Agency defines as dams for which failure or improper operation probably will cause loss of human life, to develop an emergency action plan specific to that dam. Components of an emergency action plan are to simulate a flood resulting from a possible dam breach and map the resulting downstream flood-inundation areas. The resulting flood-inundation maps can provide valuable information to city officials, emergency managers, and local residents for planning an emergency response if a dam breach occurs.

  16. Seismic stability safety evaluation of gravity dam with shear strength reduction method

    Directory of Open Access Journals (Sweden)

    Da-sheng WANG

    2009-06-01

    Full Text Available A new method of numerical seismic stability safety evaluation for a rock slope is proposed based on the analysis of a gravity dam foundation subjected to earthquake loading. The shear strengths of the weak discontinuities are divided by different shear strength reduction ratios (K and numerical seismic analysis is carried out after the static analysis is completed. With different K values, the curves of the permanent horizontal displacement of key points of the dam foundation (K-displacement curves are studied. According to the curve change, the distribution of plastic zones in the foundation, and the slow convergence of the finite element method (FEM, the seismic stability safety factor is defined as K when the gravity dam is in the limit equilibrium state subjected to earthquake loading. These concepts were applied to the evaluation of seismic stability safety of a gravity dam for a hydropower project. The analysis of the example shows that the proposed method is feasible and is an effective method of seismic stability safety evaluation.

  17. Forward modeling of seepage of reservoir dam based on ground penetrating radar

    Directory of Open Access Journals (Sweden)

    Xueli WU

    2017-08-01

    Full Text Available The risk of the reservoir dam seepage will bring the waste of water resources and the loss of life and property. The ground penetrating radar (GPR is designed as a daily inspection system of dams to improve the existing technology which can't determine the actual situation of the dam seepage tunnel coordinates. The finite difference time domain (FDTD is used to solve the Yee's grids discreatization in two-dimensional space, and its electromagnetic distribution equation is obtained as well. Based on the actual structure of reservoir dam foundation, the ideal model of air layer, concrete layer, clay layer and two water seepage holes is described in detail, and the concrete layer interference model with limestone interference point is established. The system architecture is implemented by using MATLAB, and the forward modeling is performed. The results indicate that ground penetrating radar can be used for deep target detection. Through comparing the detection spectrum of three kinds of frequency electromagnetic wave by changing the center frequency of the GPR electromagnetic wave of 50 MHz, 100 MHz and 200 MHz, it is concluded that the scanning result is more accurate at 100 MHz. At the same time, the simulation results of the interference model show that this method can be used for the detection of complex terrain.

  18. Seismic stability safety evaluation of gravity dam with shear strength reduction method

    Institute of Scientific and Technical Information of China (English)

    Da-sheng WANG; Liao-jun ZHANG; Jian-jun XU; Ming-jie HE; Wei-di ZHANG

    2009-01-01

    A new method of numerical seismic stability safety evaluation for a rock slope is proposed based on the analysis of a gravity dam foundation subjected to earthquake loading. The shear strengths of the weak discontinuities are divided by different shear strength reduction ratios (K) and numerical seismic analysis is carried out after the static analysis is completed. With different K values, the curves of the permanent horizontal displacement of key points of the dam foundation (K-displacement curves) are studied. According to the curve change, the distribution of plastic zones in the foundation, and the slow convergence of the finite element method (FEM), the seismic stability safety factor is defined as K when the gravity dam is in the limit equilibrium state subjected to earthquake loading. These concepts were applied to the evaluation of seismic stability safety of a gravity dam for a hydropower project. The analysis of the example shows that the proposed method is feasible and is an effective method of seismic stability safety evaluation.

  19. The Cotingo Dam as a test of Brazil's system for evaluating proposed developments in Amazonia

    Science.gov (United States)

    Fearnside, Philip M.; Barbosa, Reinaldo Imbrozio

    1996-09-01

    The proposed Cotingo Dam in Brazil's far northern state of Roraima is examined with the objective of drawing lessons for Brazil's system of evaluating environmental, social, and financial consequences of development decisions. The Cotingo Dam illustrates the difficulty of translating into practice the principles of economic and environmental assessment. Examination of the financial arguments for the Cotingo Dam indicates that justifications in this sphere are insufficient to explain why the project is favored over other alternatives and points to political factors as the best explanation of the project's high priority. Strong pressure from political and entrepreneurial interest groups almost invariably dominates decision making in Amazonia. The analysis indicates the inherent tendency of the present system to produce decisions in favor of large construction projects at the expense of the environment and local peoples. The requirements intended to assure proper weight for these concerns, such as the report on environmental impacts (RIMA) and the public hearing, fail to serve this role. Cotingo also provides a test case for constitutional protections restricting construction of dams in indigenous lands.

  20. GIS inundation mapping and dam breach analysis of Woolwich Dam using HEC-geoRAS

    Energy Technology Data Exchange (ETDEWEB)

    Mocan, N. [Crozier and Associates Inc., Collingwood, ON (Canada); Joy, D.M. [Guelph Univ., ON (Canada); Rungis, G. [Grand River Conservation Authority, Cambridge, ON (Canada)

    2006-07-01

    A study was conducted to determine the extent of flood inundation given a hypothetical dam breach scenario of the Woolwich Dam located in the Grand River Watershed, 2.5 km north of the Town of Elmira, Ontario. The dam is operated by the Grand River Conservation Authority and was constructed to provide low-flow augmentation to Canagagigue Creek. Advances in the computational capabilities of numerical models along with the availability of fine resolution geospatial data has lead to significant advances in the evaluation of catastrophic consequences due to the ensuing flood waters when dams fail. The hydraulic models HEC-RAS and HEC-GeoRAS were used in this study along with GIS to produce high resolution spatial and temporal flood inundation mapping. Given the proximity to the Town of Elmira, the dam is classified as having a high hazard potential. The large size and high hazard potential of the dam suggests that the Inflow Design Flood (IDF) is the Probable Maximum Flood (PMF) event. The outlet structure of the spillway consists of 4 ogee-type concrete spillways equipped with radial gates. A low-level concrete pipe located within the spillway structure provides spillage for maintenance purposes. The full flow capacity of the spillway structure is 297 cubic metres per second at the full supply level of 364.8 metres. In addition to GIS flood inundation maps, this paper included the results of flood hydrographs, water surface profiles and peak flow data. It was concluded that techniques used in this analysis should be considered for use in the development of emergency management planning and dam safety assessments across Canada. 6 refs., 3 tabs., 4 figs.

  1. National Dam Inspection Program. Lake Housatonic Dam and Dike (CT 00026 and CT 01714). Connecticut Coastal Basin, Housatonic River, Derby-Shelton, Connecticut. Phase I Inspection Report.

    Science.gov (United States)

    1981-08-01

    8217;’,.-+-.-. ""’"" . .•• "•;. - NATIONAL DAM INSPECTION PROGRAM PHASE I INSPECTION REPORT Identification No.: CT 00026, CT 01714 N *~ Name of Dam: Lake Housatonic Dam and Dike " Town...approach was used between 1868 and 1870 to strengthen the Holyoke dam. The dam that existed there at the time was a timber crib dam, 1,017 feet long and 30

  2. Earthquake Response of Concrete Gravity Dams Including Hydrodynamic and Foundation Interaction Effects,

    Science.gov (United States)

    1980-01-01

    Presas y Depositos", Boletin Sociedad Mexicana de Ingenieria Sismica, Vol. 1, No. 2, October 1963. 10. A. K. Chopra,"Hydrodynamic Pressures on Dams...Veracruz, Mexico , 1968. 12. A. Flores, I. Herrera and C. Lozano, "Hydrodynamic Pressure Generated by Vertical Earthquake Component", Proceedings, Fourth...transform of the ground motion and Nthe inverse transforms of the re- sponses are obtained at the first -T points spaced at equal intervals of time At

  3. How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation.

    Science.gov (United States)

    Fencl, Jane S; Mather, Martha E; Costigan, Katie H; Daniels, Melinda D

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0-15.3 km) or 287 wetted widths (136-437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams.

  4. Landfill liners from dam reservoir sediments

    Directory of Open Access Journals (Sweden)

    Koś Karolina

    2016-03-01

    Full Text Available Landfill liners from dam reservoir sediments. Every municipal solid waste landfill has to be properly secured to protect the natural environment from possible leachate. Most often an artificial sealing is used, which is based on a soil liner from cohesive soils (clays, silts. Usability evaluation of bottom sediments from Rzeszowski Reservoir for building these liners was presented in the paper. Sediments from dam reservoirs, gathered as a result of the siltation process, can be a valuable material for earthworks purposes. Determination of their possible ways of usage is important, especially before the planned dredging, because thanks to that this material will not be put on a heap. Based on the analysis of the geotechnical parameters of these sediments it was stated that this material can be preliminary allowed for using in liners.

  5. Augmented Reality to Access Dam Cracks Information

    Directory of Open Access Journals (Sweden)

    Fabiana Frata Furlan Peres

    2016-03-01

    Full Text Available Augmented reality technology is a tool with great potential for application in several areas, including engineering. During the early phases of the enterprise life cycle, as design and construction, augmented reality has been widely used. Concrete dams, during operation and maintenance phase, require regular inspections as part of the necessary activities to keep their structural safety. Cracks are common pathology in these structures that must be detected, mapped and measured as their evolution may evidence structure compromising, need for maintenance or intervention. In this context this paper aims to present a prototype to access in situ the dam cracks information through the use of augmented reality, thus giving a contribution to the effectiveness and efficiency of inspections

  6. Temporal and spatial distribution of dam failure events in China

    Institute of Scientific and Technical Information of China (English)

    X.Y.HE; Z.Y.WANG; J.C.HUANG

    2008-01-01

    Reservoirs play a vital role in economic development and flood control.Nevertheless,both human and natural factors may lead to dam failures with catastrophic consequences.Analyzing the data of dam failure events from 1954 to 2003 and using the method of energy spectrum analysis,this paper studies the periodicity of dam failures.The rate of failure of different dam ages is analyzed.The climate is the main factor affecting the rate of dam failure.Climate diagrams are used to analyze the spatial distribution of dam failure events in China.High rate of dam failure occurs with 25-year and 12.5-year periods.The distribution of the percentage of dam failure shows an L-shape as a function of service age.The first 5 years of operation is known as the "infant period",during which,the probability of dam failure is much higher than during any other periods.The failure rate in areas near or north to the 400 mm annual isopluvial line is notably higher than other areas.In areas with high temperature difference among seasons have a high annual average dam failure rate.

  7. Dam removal increases American eel abundance in distant headwater streams

    Science.gov (United States)

    Hitt, Nathaniel P.; Eyler, Sheila; Wofford, John E.B.

    2012-01-01

    American eel Anguilla rostrata abundances have undergone significant declines over the last 50 years, and migration barriers have been recognized as a contributing cause. We evaluated eel abundances in headwater streams of Shenandoah National Park, Virginia, to compare sites before and after the removal of a large downstream dam in 2004 (Embrey Dam, Rappahannock River). Eel abundances in headwater streams increased significantly after the removal of Embrey Dam. Observed eel abundances after dam removal exceeded predictions derived from autoregressive models parameterized with data prior to dam removal. Mann–Kendall analyses also revealed consistent increases in eel abundances from 2004 to 2010 but inconsistent temporal trends before dam removal. Increasing eel numbers could not be attributed to changes in local physical habitat (i.e., mean stream depth or substrate size) or regional population dynamics (i.e., abundances in Maryland streams or Virginia estuaries). Dam removal was associated with decreasing minimum eel lengths in headwater streams, suggesting that the dam previously impeded migration of many small-bodied individuals (dams may influence eel abundances in headwater streams up to 150 river kilometers distant, and that dam removal may provide benefits for eel management and conservation at the landscape scale.

  8. Impulsive force of debris flow on a curved dam

    Institute of Scientific and Technical Information of China (English)

    Chjeng-Lun SHIEH; Chia-Hsien TING; Hung-Wen PAN

    2008-01-01

    Although Sabo dams are an efficient method for river and basin management,traditional Sabo dams have a great impact on ecology and landscape.Moreover,such dams are hit and often damaged by great impulsive force when they block the debris flow.Therefore,alternative shapes for Sabo dam deserve thorough investigation.In this investigation,a curved dam was designed by changing the upstream-dam-surface geometric shape to reduce the impulsive force of the debris flow,with enhanced stability and reduced concrete mass being the anticipated outcomes.In this study,the flume and laboratory facilities simulated the impulsive force of the debris flow to the Sabo dams.Three geometric forms,including vertical,slanted and curved Sabo dams,were used to determine the impulsive force.Impulsive force theories of the debris flow were derived from the momentum equation and the Bernoulli equation.In these,the impulsive force was balanced by the friction force of the Sabo dam and the opposite force of the load cell behind the dam as it was hit by the debris flow.Positive correlations were found when comparing the experimental data with the theoretical results.These findings suggest that our impulsive force theory has predictive validity with regard to the experimental data.The results from both theory and experimental data clearly show that curved dams were sustained less force than the other dams under the same debris flow.This comparison demonstrates the importance of curved geometry for a well-designed Sabo dam.

  9. A climate impact of dam lake and Recep Yazicioglu Gokpinar dam lake sample

    Directory of Open Access Journals (Sweden)

    Ülker Güner BACANLI

    2016-06-01

    Full Text Available Dams have both positive and negative effects on the environment. The most important effect can be defined as the regional climate change. In this study, the impact on Denizli city climate of Vali Recep Yazıcıoğlu Gökpınar Dam Lake was determined. In this study, Denizli city meteorological station (maximum, minimum and mean temperatures, total precipitation and wind speed data were used. Before and after from the dam construction; absolute changes are examined. After the dam construction; maximum, minimum and average temperature increase was observed in all months. A rainfall was observed to be increased in January, February and October on after dam construction, but another times was observed to be decreased. The evaporation and wind speed parameter has been little change. Linear regression, the Mann-Kendall and Sen’s Method for trend analysis were used. All techniques considered here consistently reveal that there are upward trend in maximum, minimum and mean temperatures, wind speed, no trend in precipitation and evaporation.

  10. Seismic performance evaluation of concrete gravity dams

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Y.; Sasaki, T.; Kanenawa, K. [Public Works Research Institute, Tsukuba City (Japan); Hall, R.; Yule, D. [United States Army Engineer Research and Development Center, Vicksburg, MS (United States); Matheu, E. [Louisiana State Univ., Baton Rouge, LA (United States); Chudgar, A. [United States Army Corps of Engineers, Washington, DC (United States)

    2004-07-01

    This paper addresses technical issues related to seismic design practices and current evaluation methods in Japan and the United States. Nonlinear analysis procedures can identify the ultimate capacity of existing concrete dams, taking into account the most critical nonlinear phenomena controlling the response. A numerical model of a non-overflow monolith of Koyna Dam, subject to earthquake motion, is used as a case study to compare the different approaches for seismic evaluation of concrete gravity dams currently employed in the two countries. The complexity of nonlinear analysis procedures and the scarcity of appropriate calibration strategies force analysts to frequently interpret results using their own judgment. It was concluded that the influence of the input parameters and ground excitation on the nonlinear dynamic response should be investigated in order to identify the most critical conditions. It was also suggested that methodologies for qualitative damage estimation based on results from linear analyses could be used to develop a systematic assessment tool and reference framework for the adequate interpretation of results. 14 refs., 2 tabs., 13 figs.

  11. Simulating dam-breach flood scenarios of the Tangjiashan landslide dam induced by the Wenchuan Earthquake

    Directory of Open Access Journals (Sweden)

    X. Fan

    2012-10-01

    Full Text Available Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw = 7.9 2008 Wenchuan earthquake had impounded the largest lake in the earthquake affected area with an estimated volume of 3 × 108 m3, and the potential catastrophic dam breach posed a serious threat to more than 2.5 million people in downstream towns and Mianyang city, located 85 km downstream. Chinese authorities had to evacuate parts of the city until the Tangjiashan landslide dam was artificially breached by a spillway, and the lake was drained. We propose an integrated approach to simulate the dam-breach floods for a number of possible scenarios, to evaluate the severity of the threat to Mianyang city. Firstly, the physically-based BREACH model was applied to predict the flood hydrographs at the dam location, which were calibrated with observational data of the flood resulting from the artificial breaching. The output hydrographs from this model were inputted into the 1-D–2-D SOBEK hydrodynamic model to simulate the spatial variations in flood parameters. The simulated flood hydrograph, peak discharge and peak arrival time at the downstream towns fit the observations. Thus this approach is capable of providing reliable predictions for the decision makers to determine the mitigation plans. The sensitivity analysis of the BREACH model input parameters reveals that the average grain size, the unit weight and porosity of the dam materials are the most sensitive parameters. The variability of the dam material properties causes a large uncertainty in the estimation of the peak flood discharge and peak arrival time, but has little influence on the flood inundation area and flood depth downstream. The effect of cascading breaches of smaller dams downstream of the Tangjiashan dam was

  12. Do Hydroelectric Dams Mitigate Global Warming? The Case of Brazil's Curuna Dam

    Energy Technology Data Exchange (ETDEWEB)

    Fearnside, P.M. [National Institute for Research in the Amazon (INPA), C.P. 478, 69011-970 Manaus, Amazonas (Brazil)

    2005-10-15

    Hydroelectric dams in tropical forest areas emit greenhouse gases, as illustrated by the Curuna dam in the Amazonian portion of Brazil. Emissions include carbon dioxide from decay of the above-water portions of trees that are left standing in the reservoir and methane from soft vegetation that decays under anaerobic conditions on the bottom of the reservoir, especially macrophytes (water weeds) and vegetation that grows in the drawdown zone and is flooded when the reservoir water level rises. Some methane is released from the reservoir surface through bubbling and diffusion, but larger amounts are released from water passing through the turbines and spillway. Methane concentration in the water increases with depth, and the turbines and spillway draw water from sufficient depth to have substantial methane content. In 1990 (13 years after filling), the Curuna Dam emitted 3.6 times more greenhouse gases than would have been emitted by generating the same amount of electricity from oil.

  13. Passage and survival probabilities of juvenile Chinook salmon at Cougar Dam, Oregon, 2012

    Science.gov (United States)

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

    2014-01-01

    probability of RO passage was lower than previous studies based on balloon and PIT tags, but higher than a similar study based on radio transmitters. We suggest that, apart from dam operations, the differences in survival primarily are due to the release location. We hypothesize that the balloon- and PIT-tagged fish released through a hose at a point near the RO gate opening experienced more benign conditions than the radio-tagged fish passing the RO volitionally. This hypothesis could be tested with further study. An alternative hypothesis is that some live fish remained within the study area beyond the life of their radio transmitter. The results from these and previous studies indicate that entrainment and survival of juvenile salmonids passing Cougar Dam varies with dam operating conditions. The condition most conducive to dam passage has been the discharge and low pool elevation condition tested during December 2012. That condition included large RO gate openings and was the condition with the highest dam passage survival.

  14. Effects of check dams on bed-load transport and steep-slope stream morphodynamics

    Science.gov (United States)

    Piton, Guillaume; Recking, Alain

    2017-08-01

    Check dams are transversal structures built across morphologically-active streams in mountainous regions. These structures have been used widely in torrent-hazard mitigation for over 150 years. Thousands of them are regularly maintained by stream managers and torrent-control services. The stabilization role of these structures is well known, i.e. they durably constrain the stream-bed through the creation of vertical and planar fixed points. What is not yet clear is to what extent check dams influence bed-load transport: How do peak solid discharge or flood-transported volume change when check dams are added to a reach? To address these questions, long-lasting small-scale experiments were conducted in a 4.8-m-long flume with either one, three or no structures. The results show that the addition of structures creates independent compartments in the bed level, which have a strong influence on bed surface armouring and stream morphodynamics: the consequence is that instantaneous transport intensities are unchanged, but peak solid discharge occur more often and for shorter duration. This results in the same total transported volume over the long term, but reduced volume for a single transport event. It reaffirms the observation of pioneering authors of the mid-19th and early 20th century who conceptualized the possible sediment transport regulation function of check dams: in addition to stabilizing the stream-bed, check dams influence bed-load transport through a buffering effect, releasing frequently and in small doses what, in their absence, would be transported abruptly en masse during rare extreme events.

  15. A non-parametric peak calling algorithm for DamID-Seq.

    Directory of Open Access Journals (Sweden)

    Renhua Li

    Full Text Available Protein-DNA interactions play a significant role in gene regulation and expression. In order to identify transcription factor binding sites (TFBS of double sex (DSX-an important transcription factor in sex determination, we applied the DNA adenine methylation identification (DamID technology to the fat body tissue of Drosophila, followed by deep sequencing (DamID-Seq. One feature of DamID-Seq data is that induced adenine methylation signals are not assured to be symmetrically distributed at TFBS, which renders the existing peak calling algorithms for ChIP-Seq, including SPP and MACS, inappropriate for DamID-Seq data. This challenged us to develop a new algorithm for peak calling. A challenge in peaking calling based on sequence data is estimating the averaged behavior of background signals. We applied a bootstrap resampling method to short sequence reads in the control (Dam only. After data quality check and mapping reads to a reference genome, the peaking calling procedure compromises the following steps: 1 reads resampling; 2 reads scaling (normalization and computing signal-to-noise fold changes; 3 filtering; 4 Calling peaks based on a statistically significant threshold. This is a non-parametric method for peak calling (NPPC. We also used irreproducible discovery rate (IDR analysis, as well as ChIP-Seq data to compare the peaks called by the NPPC. We identified approximately 6,000 peaks for DSX, which point to 1,225 genes related to the fat body tissue difference between female and male Drosophila. Statistical evidence from IDR analysis indicated that these peaks are reproducible across biological replicates. In addition, these peaks are comparable to those identified by use of ChIP-Seq on S2 cells, in terms of peak number, location, and peaks width.

  16. A non-parametric peak calling algorithm for DamID-Seq.

    Science.gov (United States)

    Li, Renhua; Hempel, Leonie U; Jiang, Tingbo

    2015-01-01

    Protein-DNA interactions play a significant role in gene regulation and expression. In order to identify transcription factor binding sites (TFBS) of double sex (DSX)-an important transcription factor in sex determination, we applied the DNA adenine methylation identification (DamID) technology to the fat body tissue of Drosophila, followed by deep sequencing (DamID-Seq). One feature of DamID-Seq data is that induced adenine methylation signals are not assured to be symmetrically distributed at TFBS, which renders the existing peak calling algorithms for ChIP-Seq, including SPP and MACS, inappropriate for DamID-Seq data. This challenged us to develop a new algorithm for peak calling. A challenge in peaking calling based on sequence data is estimating the averaged behavior of background signals. We applied a bootstrap resampling method to short sequence reads in the control (Dam only). After data quality check and mapping reads to a reference genome, the peaking calling procedure compromises the following steps: 1) reads resampling; 2) reads scaling (normalization) and computing signal-to-noise fold changes; 3) filtering; 4) Calling peaks based on a statistically significant threshold. This is a non-parametric method for peak calling (NPPC). We also used irreproducible discovery rate (IDR) analysis, as well as ChIP-Seq data to compare the peaks called by the NPPC. We identified approximately 6,000 peaks for DSX, which point to 1,225 genes related to the fat body tissue difference between female and male Drosophila. Statistical evidence from IDR analysis indicated that these peaks are reproducible across biological replicates. In addition, these peaks are comparable to those identified by use of ChIP-Seq on S2 cells, in terms of peak number, location, and peaks width.

  17. Çokal Dam-break model and flood risk analysis (Çanakkale

    Directory of Open Access Journals (Sweden)

    Hasan Özdemir

    2011-09-01

    Full Text Available The source of the hazard which is the main factor of disasters can be made by naturally or man. These are generally independent sources, but sometimes reason of one hazard such as flood can be both naturally and man-made. Certainly, all examples in our country and the world show that, the fail of constructed structures on the rivers (e.g. dam, embankment produce a very large amount of water and damage more than the normal river floods. In this study, based on cofferdam of Çokal Dam breaching which occurred in 16 November 2007 on the Kavak River (Çanakkale, 1D modeling of probable Çokal Dam break take in the account tectonic properties of the area and analyzing of the flood risk have been done. For these purposes, Digital Elevation Model (DEM gathered contours from 1:25000 scaled topographic maps and GPS points, high and medium resolution satellite images, hydrological soil data gathered from soil maps scaled 1:25000, precipitation and discharge data in 30 years, technical properties of structures on the Kavak River and field measurement have been used as a database. All these data is processed and analyzed using Geographic Information System (GIS, Hec-GeoRAS and HEC-RAS hydraulic models and hydrologic model. Hence, Çokal Dam break modeling based on cofferdam breach modeling reveals that probable flood after the dam-break will affect Evreşe Plain and the people which get livelihood from the plain. General probable lost in agricultural product after probable flood reaches TL 12 million. Thus, as a result of human interventions to the nature will cause great harm to himself again.   

  18. Çokal Dam-break model and flood risk analysis (Çanakkale

    Directory of Open Access Journals (Sweden)

    Hasan Özdemir

    2011-09-01

    Full Text Available The source of the hazard which is the main factor of disasters can be made by naturally or man. These are generally independent sources, but sometimes reason of one hazard such as flood can be both naturally and man-made. Certainly, all examples in our country and the world show that, the fail of constructed structures on the rivers (e.g. dam, embankment produce a very large amount of water and damage more than the normal river floods. In this study, based on cofferdam of Çokal Dam breaching which occurred in 16 November 2007 on the Kavak River (Çanakkale, 1D modeling of probable Çokal Dam break take in the account tectonic properties of the area and analyzing of the flood risk have been done. For these purposes, Digital Elevation Model (DEM gathered contours from 1:25000 scaled topographic maps and GPS points, high and medium resolution satellite images, hydrological soil data gathered from soil maps scaled 1:25000, precipitation and discharge data in 30 years, technical properties of structures on the Kavak River and field measurement have been used as a database. All these data is processed and analyzed using Geographic Information System (GIS, Hec-GeoRAS and HEC-RAS hydraulic models and hydrologic model. Hence, Çokal Dam break modeling based on cofferdam breach modeling reveals that probable flood after the dam-break will affect Evreşe Plain and the people which get livelihood from the plain. General probable lost in agricultural product after probable flood reaches TL 12 million. Thus, as a result of human interventions to the nature will cause great harm to himself again.

  19. Assessment model of dam operation risk based on monitoring data

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Although the dams produce remarkable social and economic benefits,the threat made by unsafe dams to the life and property of people who live in the lower river area is un-negligible.Based on the monitoring data which reflect the safety condition of dams,the risk degree concept is proposed and the analysis system and model for evaluating risk degree (rate) are established in this paper by combining the reliability theory and field monitoring data.The analysis method for risk degree is presented based on Bayesian approach.A five-grade risk degree system for dam operation risk and corresponding risk degree is put forward according to the safety condition of dams.The operation risks of four cascade dams on some river are analyzed by the model and approach presented here and the result is adopted by the owner.

  20. Dam safety - Requirements analysis for motion measurements for ponds; Dammsaekerhet - Behovsanalys foer roerelsemaetningar foer dammar

    Energy Technology Data Exchange (ETDEWEB)

    Ekstroem, Ingvar; Lier, Oeyvind E.

    2013-04-15

    Ageing population of dams and growing societal demands on safety increases the need for monitoring to ensure that dam safety is maintained at a continuously high level. A part of this is deformation measurements of earth fill dams, for which a number of general and specific methods are available. General long-term monitoring of earth fill dams are traditionally carried out with geodetic methods such as leveling or total station which provide a good accuracy. These methods have recently been supplemented by various forms of laser scanning, both ground-based and airborne. Scanning has the advantage of better surface coverage but generally offers lower accuracy. Also GPS-based systems are available with high precision, but these usually require a large number of fixed receivers. When there are specific monitoring needs there are several methods available, such as extensometer, inclinometers, pressure cells, optical fiber or pendulum. These all have very high precision, but are costly and measures deviations at a specific point in the dam and provides no general surface scan. In recent years, technical developments of measurement systems using satellites have reached such a level that there might be opportunities to improve earth fill dam monitoring with these new methods. Since 2008, a limited commercialization of SAR technology has been going on within the monitoring of movements and deformations of sensitive land areas. Development of the software and better resolution on available satellite data has made more comprehensive and precise analyses available. Also the knowledge of the possibilities and limitations of the method has been developed. According to this study InSAR seems to have a place among methods for long-term monitoring where cost and applicability seems competitive compared to more traditional methods. The main benefits are the uniform image of deformations that can be obtained, combined with the availability of historical data that can be analyzed

  1. Predicting surfacing internal erosion in moraine core dams

    OpenAIRE

    2010-01-01

    Dams that comprise broadly and widely graded glacial materials, such as moraines, have been found to be susceptible to internal erosion, perhaps more than dams of other soil types. Internal erosion washes out fine-grained particles from the filling material; the erosion occurs within the material itself or at an interface to another dam zone, depending on the mode of initiation. Whether or not internal erosion proceeds depend on the adequacy of the filter material. If internal erosion is allo...

  2. Environmental impacts of increased hydroelectric development at existing dams

    Energy Technology Data Exchange (ETDEWEB)

    Railsback, S. F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cada, G. F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Petrich, C. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sale, M. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shaakir-Ali, J. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Watts, J. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Webb, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    1991-04-01

    This report describes the environmental impacts of a proposed U.S. Department of Energy (DOE) initiative to promote the development of hydropower resources at existing dams. Hydropower development at existing dams has, in general, fewer impacts than development of additional fossil-fueled resources or hydropower at new dams, although potential cumulative impacts of developing multiple hydropower projects have not been explicitly addressed. Environmental review of project impacts and mitigation needs can ensure that additional hydropower development at existing dams can provide a renewable resource with fewer impacts than alternative resources.

  3. Stochastic Boundary Element Analysis of Concrete Gravity Dam

    Institute of Scientific and Technical Information of China (English)

    张明; 吴清高

    2002-01-01

    Stochastic boundary integral equations for analyzing large structures are obtained from the partial derivatives of basic random variables. A stochastic boundary element method based on the equations is developed to solve engineering problems of gravity dams using random factors including material parameters of the dam body and the foundation, the water level in the upper reaches, the anti-slide friction coefficient of the dam base, etc. A numerical example shows that the stochastic boundary element method presented in this paper to calculate the reliability index of large construction projects such as a large concrete gravity dam has the advantages of less input data and more precise computational results.

  4. Dam operations affect route-specific passage and survival of juvenile Chinook salmon at a main-stem diversion dam

    Science.gov (United States)

    Perry, Russell W.; Kock, Tobias J.; Couter, Ian I; Garrison, Thomas M; Hubble, Joel D; Child, David B

    2016-01-01

    Diversion dams can negatively affect emigrating juvenile salmon populations because fish must pass through the impounded river created by the dam, negotiate a passage route at the dam and then emigrate through a riverine reach that has been affected by reduced river discharge. To quantify the effects of a main-stem diversion dam on juvenile Chinook salmon in the Yakima River, Washington, USA, we used radio telemetry to understand how dam operations and river discharge in the 18-km reach downstream of the dam affected route-specific passage and survival. We found evidence of direct mortality associated with dam passage and indirect mortality associated with migration through the reach below the dam. Survival of fish passing over a surface spill gate (the west gate) was positively related to river discharge, and survival was similar for fish released below the dam, suggesting that passage via this route caused little additional mortality. However, survival of fish that passed under a sub-surface spill gate (the east gate) was considerably lower than survival of fish released downstream of the dam, with the difference in survival decreasing as river discharge increased. The probability of fish passing the dam via three available routes was strongly influenced by dam operations, with passage through the juvenile fish bypass and the east gate increasing with discharge through those routes. By simulating daily passage and route-specific survival, we show that variation in total survival is driven by river discharge and moderated by the proportion of fish passing through low-survival or high-survival passage routes.

  5. RADIOACTIVE OR NATURAL TRACER。TECHNIQUES FOR LEAK DETERMINING OF DAM ABUTMENT

    Institute of Scientific and Technical Information of China (English)

    陈建生; 杜国平; 等

    1995-01-01

    Infiltration and localization of preferential infiltration zones at the dam abutment are measured using radioactive tracer tests of flow in boreholes,meanwhile interconnection between boreholes and the energing water points is analysed.The theory and practice of radioactive tracer synthetic detective method are described to give methods and calculation formulae used under the condition of stable flow in single well to measure permeability coefficient and hydrostatic heads.Major single hole techniques including measurement for seepage line,velocity,rate of seepage flow and relationship of recharge of groundwater in aquifers are introduced briefly.The possibilities offered by natureal tracers are analysed,uincluding electric-conduct,pH-value and temperature of water as well as stable isotopes(D,18O) and tritium.Furthermore,the sensibilities of this theory and methods were confirmed by detecting seepage flow field of Xinanjiang Dam.

  6. Monitoring health in African dams : the Kamburu dam (Kenya) as a test case

    NARCIS (Netherlands)

    J.M.V. Oomen

    1981-01-01

    textabstractDams are among the obvious efforts to improve the economic situation in a developing country. They aim at using locally available natural resources. At present they are among the most popular means for promoting socio-economic development. A significant number of these programmes have be

  7. Advanced numerical simulation of collapsible earth dams

    Energy Technology Data Exchange (ETDEWEB)

    De Farias, M.M.; Cordao Neto, M.P. [Brasilia Univ., Federal District (Brazil). Dept. of Civil and Environmental Engineering

    2010-12-15

    This paper discussed a systematic methodology for the hydromechanical coupled numerical analysis of earth dams constructed with unsaturated collapsible soil. Every design stage was considered, including construction, reservoir filling, and advance of saturation front until the steady-state flow condition is attained. A transient analysis of safety factors applicable to 3-dimensional conditions was presented, giving consideration to unsaturated materials and the interrelation between hydraulic and mechanical phenomena by solving equilibrium and continuity conditions at the same time. The finite element method was used to formulate equilibrium and continuity conditions for both soil skeleton and pore water, which necessitated a realistic mechanical model for the stress-strain-suction relation in unsaturated porous material and adequate constitutive models related to water flow and storage, giving special consideration to imposing appropriate boundary conditions for each simulation stage. The methodology was applied to the analysis of earth dams composed of soils at optimum, dry of optimum, and mixed compaction conditions. The dry section simulated dams constructed using poorly compacted, dry material, which are prone to collapse. By strategically placing the optimum materials in the areas of the earth fill that are most stressed, the mixed section could be designed less expensively with the same or better performance as the homogenous section at optimum conditions. The coupled analysis provides a higher safety factor than uncoupled analysis and a realistic picture of end-of-construction pore pressure distribution. The simulation of reservoir filling and saturation front advance permitted clear identification of the initialization, development, and evolution of internal failure mechanisms. 21 refs., 6 tabs., 19 figs.

  8. Quasi-stable Slope-Failure Dams in High Asia

    Science.gov (United States)

    Shroder, J. F.

    2010-12-01

    Collapses of steep mountain slopes in the Himalaya, Karakoram, Pamir, Hindu Kush, and Tibetan Plateau are well known as a result of:(1) generally high seismicity in active tectonic areas; (2) prior deglaciation leaving undercut, unstable cliffs; (3) present-day debuttressing of rock cliffs by glacial down-wasting in conditions of global warming; and (4) degradation of permafrost cohesion and water-ice cementation in high mountain slopes. Landslide dams across mountain rivers are also well known worldwide and generally do not endure for long because of the common landslide-lake outburst floods (LLOF) whose discharge is commonly sufficiently large to remove much of the dam in a short time. A number of massive slope-failure dams in south High Asia, however, have endured for centuries and require explanations for the length of duration, whereas recent examples require robust assessment for better predictive hazard analysis. Three main factors contribute to longevity of slope-failure dams: (1) mega-rocks >15-30 m that inhibit dam failure in overflow breaches; (2) mega-porosity wherein incoming discharge to the landslide lake is balanced by subterranean water through-flow within the landslide dam; (3) impermeable clay fills caused by remobilization of prior lacustrine-dammed sediment that impart dam strength to allow lasting integrity for a time, and (4) climate-change induced lake-level lowering. Several examples of long-lived or unusually stable, slope-failure dams associated with pronounced structural/tectonic associations include: (1) Pangong Tso, Ladakh and Tibet; (2) Lake Shewa, Afghanistan; (3) Sarez Lake, Tajikistan; and (4) Lake Hunza, Pakistan. Pangong Tso and Lake Shewa were emplaced thousands of years ago and only Lake Shewa shows some instability of the dam front where percolating water maintains lake level but may be causing new slumping. Sarez Lake behind the Usoi landslide dam was emplaced by an earthquake in 1911 and maintains its level by seepage. Lake

  9. Evaluation Model of Life Loss Due to Dam Failure

    Science.gov (United States)

    Huang, Dongjing

    2016-04-01

    Dam failure poses a serious threat to human life, however there is still lack of systematic research on life loss which due to dam failure in China. From the perspective of protecting human life, an evaluation model for life loss caused by dam failure is put forward. The model building gets three progressive steps. Twenty dam failure cases in China are preferably chosen as the basic data, considering geographical location and construction time of dams, as well as various conditions of dam failure. Then twelve impact factors of life loss are selected, including severity degree of flood, population at risk, understanding of dam failure, warning time, evacuation condition, number of damaged buildings, water temperature, reservoir storage, dam height, dam type, break time and distance from flood area to dam. And through principal component analysis, it gets four principal components consisting of the first flood character principle component, the second warning system principle component, the third human character principle component and the fourth space-time impact principle component. After multivariate nonlinear regression and ten-fold validation in combination, the evaluation model for life loss is finally established. And the result of the proposed model is closer to the true value and better in fitting effect in comparison with the results of RESCDAM method and M. Peng method. The proposed model is not only applied to evaluate life loss and its rate under various kinds of dam failure conditions in China, but also provides reliable cause analysis and prediction approach to reduce the risk of life loss.

  10. Earthquake safety assessment of concrete arch and gravity dams

    Institute of Scientific and Technical Information of China (English)

    Lin Gao; Hu Zhiqiang

    2005-01-01

    Based on research studies currently being carried out at Dalian University of Technology, some important aspects for the earthquake safety assessment of concrete dams are reviewed and discussed. First, the rate-dependent behavior of concrete subjected to earthquake loading is examined, emphasizing the properties of concrete under cyclic and biaxial loading conditions. Second, a modified four-parameter Hsieh-Ting-Chen viscoplastic consistency model is developed to simulate the rate-dependent behavior of concrete. The earthquake response of a 278m high arch dam is analyzed, and the results show that the strain-rate effects become noticeable in the inelastic range. Third, a more accurate non-smooth Newton algorithm for the solution of three-dimensional frictional contact problems is developed to study the joint opening effects of arch dams during strong earthquakes. Such effects on two nearly 300m high arch dams have been studied. It was found that the canyon shape has great influence on the magnitude and distribution of the joint opening along the dam axis. Fourth, the scaled boundary finite element method presented by Song and Wolf is employed to study the dam-reservoir-foundation interaction effects of concrete dams. Particular emphases were placed on the variation of foundation stiffness and the anisotropic behavior of the foundation material on the dynamic response of concrete dams. Finally, nonlinear modeling of concrete to study the damage evolution of concrete dams during strong earthquakes is discussed. An elastic-damage mechanics approach for damage prediction of concrete gravity dams is described as an example. These findings are helpful in understanding the dynamic behavior of concrete dams and promoting the improvement of seismic safety assessment methods.

  11. The World Commission on Dams + 10: Revisiting the Large Dam Controversy

    Directory of Open Access Journals (Sweden)

    Deborah Moore

    2010-06-01

    Full Text Available The World Commission on Dams (WCD was an experiment in multi-stakeholder dialogue and global governance concerned with a subject area – large dams – that was fraught with conflict and controversy. The WCD Report, Dams and Development: A New Framework for Decision-Making, was published in 2000 and accompanied by hopes that broad-based agreements would be forged on how to better manage water and energy development. Ten years later, this special issue of Water Alternatives revisits the WCD and its impacts, exploring the question: Is the WCD still relevant? The editorial team and the Guest Editors of this special issue of Water Alternatives have selected a range of 20 papers, 6 viewpoints, and 4 book reviews that help to illustrate the evolution in the dams debate. The goal of this special issue is to examine the influence and the impacts of the WCD on the dam enterprise, in general, and on the policies and practices of key stakeholders and institutions, and on the development outcomes for affected communities and environments, in particular. In this introduction, the Guest Editors provide an overview of the special issue, exploring the new drivers of dam development that have emerged during the last decade, including climate change and new financiers of dams, and describing the themes emerging from this diverse set of papers and viewpoints. This special issue demonstrates the need for a renewed multi-stakeholder dialogue at multiple levels. This would not be a redo of the WCD, but rather a rekindling and redesigning of processes and forums where mutual understanding, information-sharing, and norm-setting can occur. One of the most promising developments of the last decade is the further demonstration, in case studies described here, that true partnership amongst key stakeholders can produce transformative resource-sharing agreements, showing that many of the WCD recommendations around negotiated decision making are working in practice. We hope

  12. Minimum Reservoir Water Level in Hydropower Dams

    Science.gov (United States)

    Sarkardeh, Hamed

    2017-07-01

    Vortex formation over the intakes is an undesirable phenomenon within the water withdrawal process from a dam reservoir. Calculating the minimum operating water level in power intakes by empirical equations is not a safe way and sometimes contains some errors. Therefore, current method to calculate the critical submergence of a power intake is construction of a scaled physical model in parallel with numerical model. In this research some proposed empirical relations for prediction of submergence depth in power intakes were validated with experimental data of different physical and numerical models of power intakes. Results showed that, equations which involved the geometry of intake have better correspondence with the experimental and numerical data.

  13. Hovercraft drill probes Saraji tailings dam

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    In early operations at BHP-Utah's Saraji Mine in central Queensland, quantities of coking coal were pumped into the tailings dam because the preparation plant's flotation circuit was unable to handle ultra-fines. A reverse circulating drilling rig mounted on a hovercraft was used to recover 22 samples (representing 9 metres of tailings from 11 x 8 x 0.09 metre cores) in an investigation into whether the tailings can now be treated economically. 1 fig.

  14. Safety and exploitation of dams: the inspection equipments (part.1); an international facility: the hydroelectric facility of Emosson. Dams life. Activities of the control services; Securite et exploitation des barrages: les materiels d'auscultation (1. partie); un amenagement international: l'amenagement hydroelectrique d'Emosson. La vie des barrages. Activites des services du controle

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-07-01

    This issue of Barrages newsletter comprises 4 articles. The first article deals with the instruments used for the inspection of dams and the detection of any drift of dams stability. This article is the first of a series. It presents some general considerations about dams sounding and the apparatuses used. Two types of instruments are presented: the pendulums and the planimeters. The second article presents the conclusions of the decennial and annual inspections of French dams. Only the observations requiring a special follow-up are reported. The third article treats of trans-border facilities which require an international agreement. This is the case of the French-Swiss Emosson dam. The article describes the preliminary negotiations and the main points of the convention signed by both countries. The last article summarizes the activities of the control services for the second quarter of 2004: important facts, administrative instructions, studies, projects and works, services organisation of the different regional directions of industry, research and environment (DRIRE), of the technical service of electric power and big dams (STEEGB) and of the office of technical study and control of big dams (BETCGB). (J.S.)

  15. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

  16. Dynamic decision making for dam-break emergency management – Part 2: Application to Tangjiashan landslide dam failure

    Directory of Open Access Journals (Sweden)

    M. Peng

    2013-02-01

    Full Text Available Tangjiashan landslide dam, which was triggered by the Ms = 8.0 Wenchuan earthquake in 2008 in China, threatened 1.2 million people downstream of the dam. All people in Beichuan Town 3.5 km downstream of the dam and 197 thousand people in Mianyang City 85 km downstream of the dam were evacuated 10 days before the breaching of the dam. Making such an important decision under uncertainty was difficult. This paper applied a dynamic decision-making framework for dam-break emergency management (DYDEM to help rational decision in the emergency management of the Tangjiashan landslide dam. Three stages are identified with different levels of hydrological, geological and social-economic information along the timeline of the landslide dam failure event. The probability of dam failure is taken as a time series. The dam breaching parameters are predicted with a set of empirical models in stage 1 when no soil property information is known, and a physical model in stages 2 and 3 when knowledge of soil properties has been obtained. The flood routing downstream of the dam in these three stages is analyzed to evaluate the population at risk (PAR. The flood consequences, including evacuation costs, flood damage and monetized loss of life, are evaluated as functions of warning time using a human risk analysis model based on Bayesian networks. Finally, dynamic decision analysis is conducted to find the optimal time to evacuate the population at risk with minimum total loss in each of these three stages.

  17. Major Dams of the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer portrays major dams of the United States, including Puerto Rico and the U.S. Virgin Islands. The map layer was created by extracting dams 50 feet or...

  18. Numerical Modeling of Sliding Stability of RCC dam

    Science.gov (United States)

    Mughieda, O.; Hazirbaba, K.; Bani-Hani, K.; Daoud, W.

    2017-06-01

    Stability and stress analyses are the most important elements that require rigorous consideration in design of a dam structure. Stability of dams against sliding is crucial due to the substantial horizontal load that requires sufficient and safe resistance to develop by mobilization of adequate shearing forces along the base of the dam foundation. In the current research, the static sliding stability of a roller-compacted-concrete (RCC) dam was modelled using finite element method to investigate the stability against sliding. A commercially available finite element software (SAP 2000) was used to analyze stresses in the body of the dam and foundation. A linear finite element static analysis was performed in which a linear plane strain isoperimetric four node elements was used for modelling the dam-foundation system. The analysis was carried out assuming that no slip will occur at the interface between the dam and the foundation. Usual static loading condition was applied for the static analysis. The greatest tension was found to develop in the rock adjacent to the toe of the upstream slope. The factor of safety against sliding along the entire base of the dam was found to be greater than 1 (FS>1), for static loading conditions.

  19. Safety of Italian dams in the face of flood hazard

    Science.gov (United States)

    Bocchiola, Daniele; Rosso, Renzo

    2014-09-01

    Most rivers in Italy are segmented by dams that need rehabilitation because of (1) safety requirements by increasingly risk-averse societies, (2) changes in the downstream river and riparian system after dams building, (3) poor initial design at the time of completion and (4) modified priorities of watershed management. Safe design of flood spillways is a major concern, and requires to cope with low frequency flood hazard. One must estimate flood figures with high return periods (R ⩾ 1000-10,000 years) but statistical methods involve large uncertainties because of the short length of the available records. This paper investigates the return period of the design flood of existing spillways RS of large dams in Italy. We used re-normalized flood frequency approach and regionalization using the Generalized Extreme Value distribution. The estimation of the site specific index flood is carried out by simple scaling with basin area at the regional level. The result show that 55% (245) of the 448 examined dams are equipped by spillway with RS > 10,000; and 71% (315) of the dams have RS > 1000. Conversely, 29% (130) of the dams display RS routing may dampen the outflow hydrograph, but one should carefully account for the need of achieving accurate dam safety assessment of these dams based on site specific investigations, also accounting for global change forcing.

  20. Research advance in safety analysis methods for high concrete dam

    Institute of Scientific and Technical Information of China (English)

    REN; QingWen; XU; LanYu; WAN; YunHui

    2007-01-01

    High tensile stresses occurred in high concrete dams and in their foundation lead to the growing importance of their safety with the increase of concrete dam height.Without any exiting specification or successful experiences of concrete dams up to 300 m at home and abroad for reference,experts feel obliged to figure out how to perform safety analysis on high concrete dam.This paper involves the main contents and mechanical features of the safety analysis on high concrete dam and shows the current state and progress of the analysis methods.For the insufficiency and problems existing in normative methods,study on modern numerical method such as finite element method must be strengthened to find out the stress control criterion which is in accordance with the methods.Two aspects of the safety analysis of high dam--local damage from material level and integral destruction from structure level--should be considered.For the local damage,we should consider the non-homogeneity of material and strengthen the research of meso-damage mechanics.While for integral destruction of the system of high dam and its foundation,a study on non-strength theory should receive enough concerns.Further,attention should be paid to the research on the failure modes and criterions of high concrete dam failure analysis and safety evaluation,and the effect of uncertainty and classification of safety should be considered too.

  1. Measures of struggle against appearance of cracks in earth dams

    Directory of Open Access Journals (Sweden)

    Ibraeva Yulia

    2016-01-01

    Full Text Available The article describes a method calculation of the basic parameters of the transverse rows of pile of simple printed or precast dam. As well, in this article have been shown all the necessary formulas for this calculation and have been proposed solutions to prevent cracking in the dams.

  2. Geophysical methods for the assessment of earthen dams

    Science.gov (United States)

    Dams and levees are an integral part of the fluvial system in watersheds. Their stability is of utmost concern to the Nation and to those directly impacted should failure occur. There are some 88,000 dams and 110,000 miles of levees in the USA. Many of those are earthen embankments and structures su...

  3. 33 CFR 117.705 - Beaver Dam Creek.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Beaver Dam Creek. 117.705 Section 117.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.705 Beaver Dam Creek. The draw of...

  4. 78 FR 7810 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2013-02-04

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group.... L. 102-575) of 1992. The AMP includes a Federal advisory committee, the AMWG, a technical work...

  5. 75 FR 34476 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2010-06-17

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation... Interior (Secretary) is renewing the charter for the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group is to advise and to provide recommendations to the...

  6. 78 FR 21415 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2013-04-10

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group..., the AMWG, a technical work group, a Grand Canyon Monitoring and Research Center, and...

  7. 77 FR 43117 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2012-07-23

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group... Federal advisory committee, the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and...

  8. 77 FR 9265 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2012-02-16

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Glen Canyon Dam Adaptive Management Work Group... Federal advisory committee, the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and...

  9. Institutionalizing the option of dam removal: the New Hampshire initiative.

    Science.gov (United States)

    Lindloff, S D

    2003-01-01

    For two years, the State of New Hampshire has worked to institutionalize the option of dam removal. The high gradient streams that flow through the granite hills and mountains of this small northeastern state provided ideal conditions for dam construction, particularly during America's Industrial Revolution of the 1800s when mills were constructed throughout the area. With more than 4,800 dams in the state's database, there are many opportunities for the removal of dams that no longer serve a useful purpose, have become a public safety hazard and impact the river environment. Efforts to facilitate removal of dams in New Hampshire include the formation of a River Restoration Task Force and the creation of a dam removal program within the state agency responsible for regulating dams. This has led to the removal of two dams in the past year, with approximately ten additional projects in various stages of planning. A history of this agency-led initiative, as well as a discussion of the program's strengths, challenges and goals for the future are presented.

  10. How to manage the cumulative flood safety of catchment dams

    African Journals Online (AJOL)

    2008-09-15

    Sep 15, 2008 ... Sustainable Law and Engineering Group, Centre for Accounting, Governance and Sustainability, ... associated with small-dam safety and practical feedback from ... catchment dams nor the supervision over the management of .... same time in an extreme design flood event of only 1-in-200 ..... These guide-.

  11. Will the Three Gorges Dam Stand The Test of Time?

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Netizens have collected several ar-ticles about the flood-control capacity of the Three Gorges Dam. In these articles, its capacity was differently described as tackling flooding "once-in-10,000-years" "once-in- l,O00-years" or "once-in-a-century" Can you give the specifics of the flood control capacity of the dam?

  12. INTRODUCTION All earth dams in their natural state experience ...

    African Journals Online (AJOL)

    Earth Dam constructed within the Precambrian Basement Complex terrain of Southwestern Nigeria. The study was aimed at ... The 2-D resistivity structure revealed that the core of the dam embankment is .... within the rain forest region of Nigeria. The ..... (citrus Sinensis Osbeck) Stored at Ambient Tropical Condition. 251.

  13. Seepage problem in Papan dam and the treatment

    Energy Technology Data Exchange (ETDEWEB)

    Sharghi, A. [JTMA Co., Tehran (Iran, Islamic Republic of); Palassi, M. [Tehran Univ. (Iran, Islamic Republic of). Dept. of Civil Engineering

    2003-07-01

    The Papan dam in the Krygyz Republic is 97 metres high. It is located in the Osh Oblast, within a narrow and steep sided gorge on the Ak-Bura River, approximately 20 kilometres south of the City of Osh. The impoundment of the dam revealed large inflows of water to the downstream dam through the upper half of the dam and through the joints in the right abutment. A number of options were considered before a treatment method was selected. The causes of the leakage were poor grouting, and joints and fissures in the abutment. The remedial process involved the use of a plastic concrete cutoff wall extended from the crest of the dam to a depth of approximately 70 metres, in addition to the use of a grouting curtain in the right abutment. 2 figs.

  14. Sediment settling in the Latian Dam in Iran

    Institute of Scientific and Technical Information of China (English)

    Farhang BEHRANGI; Mohammad Ali BANIHASHEMI; Shayesteh MAHANI; Mohammad Reza RAHMANIAN

    2014-01-01

    Among the difficulties that influence future dam operations, reservoir sedimentation is the most problematic for engineers. This study predicted the amount and pattern of sedimentation for use in estimation of the useful lifespan of reservoirs and identification of optimal locations for outlets and intakes at the initial stages of dam design. Hydrographic surveys of different dams can provide better insight into this phenomenon. Latian Dam in Iran has conducted hydrographic surveys during 7 time periods. The amount and process of sedimentation in this reservoir were determined, and predictions of distribution of sediments were validated by well-known, common methods. The formation of a delta in the reservoir was investigated for different time periods after operation. Future problems due to the impacts of sedimentation on dam operation and the useful lifespan of the reservoir were predicted. In addition, the study results may be used for developing empirical methods to predict sedimentation patterns in other reservoirs.

  15. Management of dam safety at BC Hydro: the database tool

    Energy Technology Data Exchange (ETDEWEB)

    Oswell, Terry [BC Hydrom Burnaby, (Canada)

    2010-07-01

    BC Hydro has a wide range of dams, which raises a wide range of issues at many unique sites. A dam safety database was developed in 2000 to deal with the complexity and volume of information provided by deficiency investigations and surveillances. The database contains all documented deficiencies and non-conformances identified in the past 10 years. It records the risk ratings assigned to each issue. This paper described the implementation of the database tool, from the characterization of a dam safety issue to the use of the database itself. The dam safety database is now a key tool in managing the dam safety program at BC Hydro and has been useful for the last 10 years or so in prioritizing the program of deficiency investigations and capital projects. The development of a process to rate non-conformances is currently under study and will be implemented soon to aid in more efficient prioritization of maintenance activities.

  16. Modeling Experiment of Break of Debris-Flow Dam

    Institute of Scientific and Technical Information of China (English)

    CHENG Zunlan; GENG Xueyong; DANG Chao; LIU Jingjing

    2007-01-01

    Glaciers are extensively developed in the southwest of Tibet and the moraines are widely distributed with large depth. Large-scale debris flows are often reported which blocked rivers and formed dams. In this paper, seven large debris flows in four valleys are discussed, among which five dams developed. 13 sets of experiments have been conducted in laboratory to simulate the formation and failure of the dam. Finally, a model of dam failure is proposed and a formula is established to calculate the flood discharge:Q = kbhhk/T (B)/LG0.41, where bk is the outlet width of the dam atthe original water level, ht the erosive depth, T the time fromoverflow to final state of failure, the average width of lake; L thelength of the lake, and G the total potential energy of the water inthe lake.

  17. Hydrological Effects of Chashm Dam on the Downstream of Talar River Watershed

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Khaleghi

    2017-02-01

    Full Text Available Introduction: In the last century, dams have constructed with the objective of water supplies for agriculture, drinking water and industry. However, the results from the performance review of dams show adverse effects on the downstream environment and the availability of water resources. The purpose of the Chashm dam construction on the TalarRiver's tributaries is the water supply for Semnan city. Materials and Methods: This study was conducted in TalarRiver watershed. TalarRiveroriginatesfrom AlborzMountains in Mazandaran province, in the southern Caspian Sea basin, in north of Iran and flows parallel with the Firouzkooh-Ghaemshahr road and it arrives to the Caspian beach area in the Malek Kala village. In order to supply the water requirements of Semnan city, the construction of Chashm dam on the TalarRiver's tributaries placed on the agenda of the Ministry of Energy. However, because of the uncontrolled exploitation of agricultural streams and invasion of privacy riverbed, the TalarRiver has acute and critical conditions from the point of hydrologic and environmental. To study the hydrological impacts of Chashm dam, Talar watershed was considered with an area of approximately 1057 square kilometers of the Pole Sefid gauging station using a rainfall-runoff model. Results and Discussion: Simulation of the study area hydrological behavior shows that the Chashm Dam average water discharge is near to 8.6 million m3. This figure will be significant changes during wet and droughtperiods. The minimum and maximum monthly discharge of the Chashm Dam watershed in August and February is equal to 0.31 and 0.55 m3/s respectively. The minimum and maximum monthly water demand in turn in October and August is equal to 0.015 and 0.4 m3/s respectively and this shows that the river discharge in June is lower than the downstream water demand. Based on confirmed studies of the Kamandab Consulting Engineers, drinking water requirement of Semnan province, water

  18. Channel evolution on the dammed Elwha River, Washington, USA

    Science.gov (United States)

    Draut, A.E.; Logan, J.B.; Mastin, M.C.

    2011-01-01

    Like many rivers in the western U.S., the Elwha River, Washington, has changed substantially over the past century in response to natural and human forcing. The lower river is affected by two upstream dams that are slated for removal as part of a major river restoration effort. In preparation for studying the effects of dam removal, we present a comprehensive field and aerial photographic analysis of dam influence on an anabranching, gravel-bed river. Over the past century with the dams in place, loss of the upstream sediment supply has caused spatial variations in the sedimentary and geomorphic character of the lower Elwha River channel. Bed sediment is armored and better sorted than on the naturally evolving bed upstream of the dams. On time scales of flood seasons, the channel immediately below the lower dam is fairly stable, but progresses toward greater mobility downstream such that the lowermost portion of the river responded to a recent 40-year flood with bank erosion and bed-elevation changes on a scale approaching that of the natural channel above the dams. In general, channel mobility in the lowest 4 km of the Elwha River has not decreased substantially with time. Enough fine sediment remains in the floodplain that – given sufficient flood forcing – the channel position, sinuosity, and braiding index change substantially. The processes by which this river accesses new fine sediment below the dams (rapid migration into noncohesive banks and avulsion of new channels) allow it to compensate for loss of upstream sediment supply more readily than would a dammed river with cohesive banks or a more limited supply of alluvium. The planned dam removal will provide a valuable opportunity to evaluate channel response to the future restoration of natural upstream sediment supply.

  19. Check dam and polyacrylamide performance under simulated stormwater runoff.

    Science.gov (United States)

    Kang, Jihoon; McCaleb, Melanie M; McLaughlin, Richard A

    2013-11-15

    High levels of turbidity and fine suspended sediments are often found in stormwater discharges from construction sites even when best management practices (BMPs) for sediment control are in place. This study evaluated turbidity reduction by three check dam types: 1) rock check dam representing a standard BMP, 2) excelsior wattle representing a fiber check dam (FCD), and 3) rock check dam wrapped with excelsior erosion control blanket (rock + excelsior ECB) representing an alternative FCD. Three check dams (all same type) were installed in a lined, 24-m ditch on a 5-7% slope and three consecutive simulated stormwater flows were run in the ditch. Additional tests were performed by adding granular polyacrylamide (PAM) on the check dams in the same manner using two sediment sources differing in clay content. Without PAM treatment, significantly higher effluent turbidity (>900 nephelometric turbidity units (NTU)) exited the ditch with rock check dams than with excelsior wattles or rock + excelsior ECBs (dam types was in the order of excelsior wattle > rock + excelsior ECB > rock check dam, indicating better water pooling behind the wattle. The PAM treatment reduced turbidity substantially (>75% relative to no PAM treatment) for all check dam types and it was very effective in excelsior wattles (<57 NTU) and rock + excelsior ECBs (<90 NTU) even during the third storm event. This study demonstrates that the passive treatment of runoff with PAM on FCDs (or rock + excelsior ECB) in construction site ditches can be very effective for sediment retention and turbidity reduction.

  20. Geophysical Investigations at Hidden Dam, Raymond, California Flow Simulations

    Science.gov (United States)

    Minsley, Burke J.; Ikard, Scott

    2010-01-01

    Numerical flow modeling and analysis of observation-well data at Hidden Dam are carried out to supplement recent geophysical field investigations at the site (Minsley and others, 2010). This work also is complementary to earlier seepage-related studies at Hidden Dam documented by Cedergren (1980a, b). Known seepage areas on the northwest right abutment area of the downstream side of the dam was documented by Cedergren (1980a, b). Subsequent to the 1980 seepage study, a drainage blanket with a sub-drain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren (1980a, b) suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain in the downstream portion of the dam. The current modeling study is aimed at quantifying how variability in dam and foundation hydrologic properties influences seepage as a function of reservoir stage. Flow modeling is implemented using the COMSOL Multiphysics software package, which solves the partially saturated flow equations in a two-dimensional (2D) cross-section of Hidden Dam that also incorporates true downstream topography. Use of the COMSOL software package provides a more quantitative approach than the flow net analysis by Cedergren (1980a, b), and allows for rapid evaluation of the influence of various parameters such as reservoir level, dam structure and geometry, and hydrogeologic properties of the dam and foundation materials. Historical observation-well data are used to help validate the flow simulations by comparing observed and predicted water levels for a range of reservoir elevations. The flow models are guided by, and

  1. Safety and coping strategy for high dam under complex natural conditions

    Institute of Scientific and Technical Information of China (English)

    Niu Xinqiang

    2012-01-01

    In respect to current situation and new challenges for high dam construction in China, safety problems are an- alyzed for high dam construction under complex natural conditions such as high elevation, cold area, high seismic inten- sity, large-seale landslide and high dam and huge reservoirs with dam types such as concrete surface rock-fill, asphalt concrete core, roller compacted concrete (RCC) arch dam and so on. From several aspects, including risk response measures for high dam, strengthening safety awareness for high dam design and construction, improving high dam con- struetion technique, intelligent dam safety management system based on IT, developing dam rehabilitation and mainte- nance technologies, useful dam safety and coping strategy is proposed.

  2. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... see news reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The ...

  3. Nuclear magnetic resonance solution structure of the peptidoglycan-binding SPOR domain from Escherichia coli DamX: insights into septal localization.

    Science.gov (United States)

    Williams, Kyle B; Yahashiri, Atsushi; Arends, S J Ryan; Popham, David L; Fowler, C Andrew; Weiss, David S

    2013-01-29

    SPOR domains are present in thousands of bacterial proteins and probably bind septal peptidoglycan (PG), but the details of the SPOR-PG interaction have yet to be elucidated. Here we characterize the structure and function of the SPOR domain for an Escherichia coli division protein named DamX. Nuclear magnetic resonance revealed the domain comprises a four-stranded antiparallel β-sheet buttressed on one side by two α-helices. A third helix, designated α3, associates with the other face of the β-sheet, but this helix is relatively mobile. Site-directed mutagenesis revealed the face of the β-sheet that interacts with α3 is important for septal localization and binding to PG sacculi. The position and mobility of α3 suggest it might regulate PG binding, but although α3 deletion mutants still localized to the septal ring, they were too unstable to use in a PG binding assay. Finally, to assess the importance of the SPOR domain in DamX function, we constructed and characterized E. coli mutants that produced DamX proteins with SPOR domain point mutations or SPOR domain deletions. These studies revealed the SPOR domain is important for multiple activities associated with DamX: targeting the protein to the division site, conferring full resistance to the bile salt deoxycholate, improving the efficiency of cell division when DamX is produced at normal levels, and inhibiting cell division when DamX is overproduced.

  4. The Political Ecology of Chinese Large Dams in Cambodia: Implications, Challenges and Lessons Learnt from the Kamchay Dam

    Directory of Open Access Journals (Sweden)

    Giuseppina Siciliano

    2016-09-01

    Full Text Available Given the opportunities offered by foreign investment in energy infrastructure mostly by Chinese firms, the Government of Cambodia is giving high priority to developing hydropower resources for reducing energy poverty and powering economic growth. Using a “Political ecology of the Asian drivers” framework, this paper assesses China’s involvement in the development of large dams’ in Cambodia and its impacts on the access of natural resources such as water and energy by dam builders, local communities and the government. This analysis is based on 61 interviews and 10 focus group discussions with affected communities, institutional actors, Chinese dam builders and financiers in relation to the first large Chinese dam built in Cambodia: the Kamchay dam. Based on the results of the analysis this paper makes recommendations on how to improve the planning, implementation and governance of future large dams in Cambodia.

  5. Stability of earth dam with a vertical core

    Directory of Open Access Journals (Sweden)

    Orekhov Vyacheslav Valentinovich

    2016-01-01

    Full Text Available Earth dam with impervious element in the form of asphaltic concrete core is currently the most promising type of earth dams (due to simple construction technology and universal service properties of asphaltic concrete and is widely used in the world. However, experience in the construction and operation of high dams (above 160 m is not available, and their work is scarcely explored. In this regard, the paper discusses the results of computational prediction of the stress-strain state and stability of a high earth dam (256 m high with the core. The authors considered asphaltic concrete containing 7 % of bitumen as the material of the core. Gravel was considered as the material of resistant prisms. Design characteristics of the rolled asphaltic concrete and gravel were obtained from the processing of the results of triaxial tests. The calculations were performed using finite element method in elastoplastic formulation and basing on the phased construction of the dam and reservoir filling. The research shows, that the work of embankment dam with vertical core during filling of the reservoir is characterized by horizontal displacement of the lower resistant prism in the tailrace and the formation of a hard wedge prism descending along the core in the upper resistant prism. The key issue of the safety assessment is to determine the safety factor of the overall stability of the dam, for calculation of which the destruction of the earth dam is necessary, which can be done by reducing the strength properties of the dam materials. As a results of the calculations, the destruction of the dam occurs with a decrease in the strength characteristics of the materials of the dam by 2.5 times. The dam stability depends on the stability of the lower resistant prism. The destruction of its slope occurs on the classical circular-cylindrical surface. The presence of a potential collapse surface in the upper resistant prism (on the edges of the descending wedge does

  6. Triclosan exposure reduces thyroxine levels in pregnant and lactating rat dams and in directly exposed offspring.

    Science.gov (United States)

    Axelstad, Marta; Boberg, Julie; Vinggaard, Anne Marie; Christiansen, Sofie; Hass, Ulla

    2013-09-01

    Thyroid disrupting chemicals can potentially disrupt brain development. Two studies investigating the effect of the antibacterial compound triclosan on thyroxine (T₄) levels in rats are reported. In the first, Wistar rat dams were gavaged with 75, 150 or 300 mg triclosan/kg bw/day throughout gestation and lactation. Total T₄ serum levels were measured in dams and offspring, and all doses of triclosan significantly lowered T₄ in dams, but no significant effects on T₄ levels were seen in the offspring at the end of the lactation period. Since this lack of effect could be due to minimal exposure through maternal milk, a second study using direct per oral pup exposure from postnatal day 3-16 to 50 or 150 mg triclosan/kg bw/day was performed. This exposure pointed to significant T₄ reductions in 16 day old offspring in both dose groups. These results corroborate previous studies showing that in rats lactational transfer of triclosan seems limited. Since an optimal study design for testing potential developmental neurotoxicants in rats, should include exposure during both the pre- and postnatal periods of brain development, we suggest that in the case of triclosan, direct dosing of pups may be the best way to obtain that goal.

  7. Estimating Snow Budget of Karaj Dam Reservoir

    Directory of Open Access Journals (Sweden)

    Manijeh G. Tali

    2009-01-01

    Full Text Available Problem statement: Most of the cold period precipitation of Karaj Basin falls in the form of snow. This snow and its run off are important to the dam and the local needs such as agriculture and the drinking water of Tehran. But due to the scarcity and in some elevations the lack of weather stations, measuring this snow cover and its run off is difficult. We have decided to estimate the amount of this snow cover by using surrogate methods such as satellite images of MODIS and temperature thresholds. Approach: To estimate the snow water budget of the Karaj Dam Reservoir Basin, first a temperature threshold of 3° Celsius was defined according to the analysis of daily temperature and precipitation values of Nesa station during 1960-2000. The elevation of this temperature was as low as 1590 m in February and 5734 m in August. During each month the melting snow was computed over the area between 3 and zero degrees Celsius and precipitation below zero degrees was considered as permanent snow cover. The precipitation of areas above 3° was computed as rain. Using this temperature threshold and the DEM map of the basin we estimated the snow cover and snow melt water of the basin. The snow cover area on the MODIS images was estimated and compared with that computed from temperature threshold. Both methods gave relatively similar results. At the end the snow melt water of the whole cold period was calculated and added up to estimate the total snow water budget. Results: The results showed that during the study months most (67.7% of the precipitation comes in the form of snow. And most of this snow (97.5% melts during months March and onward. Its monthly distributions are 3.8% in March, 22.7% in April and 71% in May. The total snow water entering the dam was about 181.73 million cubic meters. Conclusion: The comparison of the results from temperature thresholds with the MODIS images snow cover showed very little and negligible discrepancy. Therefore, this

  8. Dam overtopping risk using probabilistic concepts – Case study: The Meijaran Dam, Iran

    Directory of Open Access Journals (Sweden)

    Ehsan Goodarzi

    2013-06-01

    Full Text Available Hydrologic risk assessment and uncertainty analysis by mathematical and statistical methods provide useful information for decision makers. This study presents the application of risk and uncertainty analysis to dam overtopping due to various inflows and wind speeds for the Meijaran Dam in the north of Iran. The procedure includes univariate flood and wind speed frequency analyses, reservoir routing, and integration of wind set-up and run-up to calculate the reservoir water elevation. Afterwards, the probability of overtopping was assessed by applying two uncertainty analysis methods (Monte Carlo simulation and Latin hypercube sampling, and considering the quantile of flood peak discharge, initial depth of water in the reservoir, and spillway discharge coefficient as uncertain variables. The results revealed that rising water level in the reservoir is the most important factor in overtopping risk analysis and that wind speed also has a considerable impact on reservoirs that are placed in windy areas.

  9. Fosfortab fra det dyrkede areal til Stevning Dam, Hindemaj og Haderslev Dam

    DEFF Research Database (Denmark)

    Andersen, Hans Estrup; Heckrath, Goswin; Thodsen, Hans;

    Størrelsen af dyrkningsbidraget til søerne i Haderslev Dam-systemet er vurderet med to forskellige metoder til at udgøre ca. 42 % af den samlede tilførsel. En risikokortlægning med det nye, danske P-indeks viser, at i alt 15 % af det dyrkede areal er i højrisiko mht. fosfortab. P-indeks-kortlægni......Størrelsen af dyrkningsbidraget til søerne i Haderslev Dam-systemet er vurderet med to forskellige metoder til at udgøre ca. 42 % af den samlede tilførsel. En risikokortlægning med det nye, danske P-indeks viser, at i alt 15 % af det dyrkede areal er i højrisiko mht. fosfortab. P...

  10. Calculation Model of Equivalent Strength for Induced Crack Based on Double-K Fracture Theory and Its Optimizing Setting in RCC Arch Dam

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaogang; SONG Yupu; WU Zhimin

    2005-01-01

    By means of fracture testing on roller-compacted concrete (RCC) three-point bending beams with two different specimen sizes, the P-CMOD complete curve for RCC was gained. Furthermore, by applying double-K fracture theory, KiniⅠC,KunⅠC, as well as the critical effective crack length and the critical crack tip opening displacement, were evaluated. Based on the double-K fracture parameters above, the calculation model of equivalent strength for induced crack was established, thus the calculation method on its initiation, stable propagation and unstable fracture was ascertained. Moreover, the finite element simulation analysis of stress field in ShaPai arch dam and the on-site observational splaying points of induced crack at different altitudes validated the reliability of the model. Finally, crack inducer's optimal setting in RCC arch dam was studied. It improves the design level of induced crack in RCC arch dam and satisfies the necessity of engineering practice.

  11. Evaluating temporal changes in hydraulic conductivities near karst-terrain dams: Dokan Dam (Kurdistan-Iraq)

    Science.gov (United States)

    Dafny, Elad; Tawfeeq, Kochar Jamal; Ghabraie, Kazem

    2015-10-01

    Dam sites provide an outstanding opportunity to explore dynamic changes in the groundwater flow regime because of the high hydraulic gradient rapidly induced in their surroundings. This paper investigates the temporal changes of the hydraulic conductivities of the rocks and engineered structures via a thorough analysis of hydrological data collected at the Dokam Dam, Iraq, and a numerical model that simulates the Darcian component of the seepage. Analysis of the data indicates increased seepage with time and suggests that the hydraulic conductivity of the rocks increased as the conductivity of the grout curtain decreased. Conductivity changes on the order of 10-8 m/s, in a 20-yr period were quantified using the numerical analysis. It is postulated that the changes in hydraulic properties in the vicinity of Dokan Dam are due to suspension of fine materials, interbedded in small fissures in the rocks, and re-settlement of these materials along the curtain. Consequently, the importance of the grout curtain to minimize the downstream seepage, not only as a result of the conductivity contrast with the rocks, but also as a barrier to suspended clay sediments, is demonstrated. The numerical analysis also helped us to estimate the proportion of the disconnected karstic conduit flow to the overall flow.

  12. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species

    OpenAIRE

    Leu, Stephan T.; C Michael Bull

    2016-01-01

    Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa) during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantiall...

  13. Estimates o the risks associated with dam failure

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaswamy, P.; Hauss, B.; Hseih, T.; Moscati, A.; Hicks, T.E.; Okrent, D.

    1974-03-01

    The probabilities and potential consequences of dam failure in California, primarily due to large earthquakes, was estimated, taking as examples eleven dams having a relatively large population downstream. Mortalities in the event of dam failure range from 11,000 to 260,000, while damage to property may be as high as $720 million. It was assumed that an intensity IX or X earthquake (on the Modified Mercalli Scale) would be sufficient to completely fail earthen dams. Predictions of dam failure were based on the recurrence times of such earthquakes. For the dams studied, the recurrence intervals for an intensity IX earthquake varied between 20 and 800 years; for an intensity X between 50 and 30,000 years. For the Lake Chabot and San Pablo dams (respectively 20, 30 years recurrent earthquake times for a intensity X) the associated consequences are: 34,000 (Lake Chabot) and 30,000 (San Pablo) people killed; damage $140 million and $77 million. Evaculation was found to ameliorate the consequences slightly in most cases because of the short time available. Calculations are based on demography, and assume 10 foot floodwaters will drown all in their path and destroy all one-unit homes in the flood area. Damage estimates reflect losses incurred by structural damage to buildings and do not include loss of income. Hence the economic impact is probably understated.

  14. Environmental and dam effects on cannibalism in Wistar rat litters

    Directory of Open Access Journals (Sweden)

    Graziela Tarôco

    2015-08-01

    Full Text Available The factors related to cannibalistic behavior of dams in a Wistar rat colony are identified and analyzed. The maternal genetic effects were tested as a random effect by the method of generalized linear models. The season at parturition, the dam´s age at parturition and the density of the room at parturition were tested as fixed effects, whereas the litter size at birth was tested as a co-variable. The genetic effect of the dam was significant for the number of cannibalized pups. Although the season at parturition, the dam´s age and room density on the day of parturition were not individually significant (p > 0.05, most of the interactions between the variation sources were significant (p < 0.05. Cannibalism occurred mostly in dams aged over 241 days, with parturition during spring. So that occurrences of cannibalism could be avoided, dams with the smallest number of cannibalized pups should be selected, coupled to dams younger than 241 days, breeding during spring. The above strategies may reduce the number of couples in the vivarium and increase their production efficiency.

  15. Responses of riparian reptile communities to damming and urbanization

    Science.gov (United States)

    Hunt, Stephanie D.; Guzy, Jacquelyn C.; Price, Steven J.; Halstead, Brian J.; Eskew, Evan A.; Dorcas, Michael E.

    2013-01-01

    Various anthropogenic pressures, including habitat loss, threaten reptile populations worldwide. Riparian zones are critical habitat for many reptile species, but these habitats are also frequently modified by anthropogenic activities. Our study investigated the effects of two riparian habitat modifications-damming and urbanization-on overall and species-specific reptile occupancy patterns. We used time-constrained search techniques to compile encounter histories for 28 reptile species at 21 different sites along the Broad and Pacolet Rivers of South Carolina. Using a hierarchical Bayesian analysis, we modeled reptile occupancy responses to a site's distance upstream from dam, distance downstream from dam, and percent urban land use. The mean occupancy response by the reptile community indicated that reptile occupancy and species richness were maximized when sites were farther upstream from dams. Species-specific occupancy estimates showed a similar trend of lower occupancy immediately upstream from dams. Although the mean occupancy response of the reptile community was positively related to distance downstream from dams, the occupancy response to distance downstream varied among species. Percent urban land use had little effect on the occupancy response of the reptile community or individual species. Our results indicate that the conditions of impoundments and subsequent degradation of the riparian zones upstream from dams may not provide suitable habitat for a number of reptile species.

  16. The collapse of the Sella Zerbino gravity dam.

    Science.gov (United States)

    Petaccia, G; Lai, C G; Milazzo, C; Natale, L

    2016-08-23

    When a severe flood wave completely filled the Ortiglieto reservoir on August 13, 1935, the 14 m high "Sella Zerbino" secondary dam failed catastrophically causing > 100 casualties. Both of the dams, Sella Zerbino-Zerbino Saddle and Bric Zerbino-Zerbino Peak (Fig. 1) were overtopped but only the Sella Zerbino failed whereas the main barrage did not suffer any damage. The lawsuit that followed this tragic event ended with a full acquittal of the dam's designers since the plaintiff experts succeeded in demonstrating that the collapse was due to an extreme rainfall storm of unpredictable intensity. The case was then officially closed and still today the failure of the Sella Zerbino dam is attributed to the unpredictable hydrological event. Recently, Natale and Petaccia (2013) re-examined the case assessing the capacity of the flood spillways which equipped the Bric Zerbino dam. This paper thoroughly reviews the mechanics of the collapse of the Sella Zerbino dam focusing on the stability of the structure. The water pressure underneath the dam and the poor quality of the foundation rock is believed to have played a major role in the sequence of events that ended in the collapse of the barrage.

  17. Characterization of colostrum from dams of BLV endemic dairy herds.

    Science.gov (United States)

    Gutiérrez, Gerónimo; Lomonaco, Marina; Alvarez, Irene; Fernandez, Fernando; Trono, Karina

    2015-06-12

    Bovine Leukemia Virus (BLV) is endemic in Argentina, where the individual prevalence is higher than 80% in dairy farms. The aim of this work was to find preliminary evidence to know if the high level of infection of the dam would implicate a higher challenge to her own offspring. We collected 65 sets of samples consisting of dam's blood and colostrum from two heavily infected dairy farms, and investigated the correlation between the dam's blood proviral load and the presence of provirus in colostrum. We also described the dual antibody/provirus profile in the colostrum. Provirus was detected in 69.23% of the colostrum samples, mostly from dams with a high proviral load, 36/45 (80%). Colostrum proviral load was significantly higher in dams with high blood proviral load (pcolostrum samples all along the antibody distribution, even in those with a low amount of antibodies. These results show that even when high blood proviral load dams offer higher levels of infected cells to their offspring through colostrum they also offer higher levels of protection of antibodies. On the contrary, low blood proviral load dams also offer infected cells but a poor content of antibodies, suggesting that these animals could play an important role in the epidemiological cycle of transmission.

  18. Safety of small and medium dams in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    Rudolf V.Zhang; Sergey A.Velikin

    2014-01-01

    Safe operation and performance of dams is one of the key issues in permafrost regions. At present, the existing dams are 40 45 years old and they are reaching their design life limit. Intensive geocryological processes (thermokarst, thermal erosion, frost heaving, suffosion, concentrated seepage along the voids left by melt ice and others) begin to develop at the early stages of construction. These processes are even more intensive under severe climatic conditions of the permafrost zone due to the large thermal and moisture gradients and the resulting complex thermal stress strain state in the structures. Determining safety criteria is a critical and difficult task in dam safety management. The existing procedures need to be continuously refined and improved depending on dam importance class. Some researchers recommend introducing process development criteria (stability, destabilization, and extremality) for more objective assessment of dam safety, in addition to the existing two condition criteria. In other words, they call for a multi factor dam environment interaction system. A case study of safety declaration for an existing dam is presented.

  19. Deformation reinforcement theory and its application to high arch dams

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,the deformation reinforcement theory(DRT) proposed by the authors is elaborated with a new definition of instability that an elasto-plastic structure is not stable if it cannot satisfy simultaneously equilibrium condition,kinematical admissibility and constitutive equations under the prescribed loading.Starting from the definition,a proof is established to the principle of minimum plastic complementary energy for failured structures.It is revealed that the principle of mini-mum plastic complementary energy results in relaxed constitutive equations,especially,yield conditions.It is demonstrated with case studies that many key issues in arch dam design,e.g.,global stability,dam-toe reinforcement,dam-toe cracking,dam-abut-ment reinforcement,can be well solved within the framework of the deformation reinforcement theory.The structural global stability can be described by the curve of the plastic complementary energy vs overloading factor.The unbalanced-forces obtained by elasto-plastic FEM can be used as the basis of analysis of global stability,dam-heel cracking,dam-toe anchorage and reinforcement of faults of high arch dams and their foundations.

  20. Minidoka Dam Wildlife Impact Assessment: Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Robert C.; Meuleman, G. Allyn

    1989-03-01

    A wildlife impact assessment has been developed for the US Bureau of Reclamation's Minidoka Dam and Reservoir in south central Idaho. This assessment was conducted to fulfill requirements of the Fish and Wildlife Program. Specific objectives of this study included the following: select target wildlife species, and identify their current status and management goals; estimate the net effects on target wildlife species resulting from hydroelectric development and operation; recommend protection, mitigation, and enhancement goals for target wildlife species affected by hydroelectric development and operation; and consult and coordinate impact assessment activities with the Northwest Power Planning Council, Bonneville Power Administration, US Bureau of Reclamation, Bureau of Land Management, Shoshone-Bannock Tribes, US Fish and Wildlife Service, Pacific Northwest Utilities Conference Committee, and other entities expressing interest in the project. 62 refs., 2 figs., 11 tabs.

  1. Risk Perception Analysis Related To Existing Dams In Italy

    Science.gov (United States)

    Solimene, Pellegrino

    2013-04-01

    In the first part of this work, the progress of Italian National Rules about dams design, construction and operation are presented to highlight the strong connection existing between the promulgation of new decrees, as a consequence of a dam accidents, and the necessity to prevent further loss of lives and goods downstream. Following the Gleno Dam failure (1923), a special Ministerial Committee wrote out the first Regulations and made the proposal to establish, within the High Council of Public Works, a special department that become soon the "Dam Service", with the tasks of control and supervision about construction and operation phases of the dams and their reservoirs. A different definition of tasks and the structure of Dam Service were provided in accordance with law n° 183/1989, which transferred all the technical services to the Office of the Prime Minister; the aim was to join the Dam Office with the Department for National Technical Services, with the objective of increasing the knowledge of the territory and promoting the study on flood propagation downstream in case of operations on bottom outlet or hypothetical dam-break. In fact, population living downstream is not ready to accept any amount of risk because has not a good knowledge of the efforts of experts involved in dam safety, both from the operators and from the safety Authority. So it's important to optimize all the activities usually performed in a dam safety program and improve the emergency planning as a response to people's primary needs and feeling about safety from Civil Protection Authority. In the second part of the work, a definition of risk is provided as the relationship existing between probability of occurrence and loss, setting out the range within to plan for prevention (risk mitigation), thanks to the qualitative assessment of the minimum safety level that is suited to assign funds to plan for Civil Protection (loss mitigation). The basic meaning of the reliability of a zoned

  2. On monolithic stability and reinforcement analysis of high arch dams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  3. River turbidity and sediment loads during dam removal

    Science.gov (United States)

    Warrick, Jonathan A.; Duda, Jeffrey J.; Magirl, Christopher S.; Curran, Chris A.

    2012-01-01

    Dam decommissioning has become an important means for removing unsafe or obsolete dams and for restoring natural fluvial processes, including discharge regimes, sediment transport, and ecosystem connectivity [Doyle et al., 2003]. The largest dam-removal project in history began in September 2011 on the Elwha River of Washington State (Figure 1a). The project, which aims to restore the river ecosystem and increase imperiled salmon populations that once thrived there, provides a unique opportunity to better understand the implications of large-scale river restoration.

  4. Seismic rehabilitation and analysis of Chaohe earth dam

    Institute of Scientific and Technical Information of China (English)

    Lei Fu; Xiangwu Zeng

    2005-01-01

    Stability of earth dams during earthquakes has been a major concern for geotechnical engineers in seismic active regions. Liquefaction induced slope failure occurred at the upstream slope of a major earth dam in the suburb of Beijing, China, during the 1976 Tangshan Earthquake. The gravelly soil with loose initial condition liquefied under relatively small ground vibration. In recent years, a major seismic rehabilitation project was carried out on a similar earth dam nearby using dumped quarry stone. Seismic stability analysis was carried out using model test, finite element simulation, and pseudostatic slope stability program after taking into account the influence of excess pore pressure.

  5. The Effects of the Anti-Dam Movement on the Environmental Protection in American West

    Institute of Scientific and Technical Information of China (English)

    赵倩

    2009-01-01

    This paper examines the far - reaching influence of anti - dam movement on the protection of environment in the second half of the 20th century in American West. It first introduces the historical background of dams built along the Colorado Biver - the most important river in the West, especially the construction of Hoover Dam and Glen Canyon Dam. Then, the criticism of dams on the Colorado is examined with the emphasis on the anti - dam movement resulting from the awareness of the negative ecological impacts on the Colorado. In the conclusion, the author demonstrates the unparallel historical significance of the anti -dam movement in the en-vironmentalism in developing the American West.

  6. Lessons learned from Wenchuan earthquake for seismic safety of large dams

    Institute of Scientific and Technical Information of China (English)

    Chen Houqun

    2009-01-01

    This paper describes some special features of the Wenchuan earthquake that affected dam safety. Damage and performance of dams, primarily for four dams over 100 m high located in the affected earthquake area, are briefly described.Lessons learned related to dam safety from this devastating earthquake are preliminarily drawn. As the seismic safety of high dams during strong earthquakes has gained more attention around the world, some critical issues related to dam construction in China are considered and extensively discussed. Questions such as "Why is dam construction necessary in earthquake prone countries such as China?", "Can we accurately evaluate the seismic safety of high dams in China?", "Did reservoir impounding of the Zipingpu and Three Gorges Projects trigger the Wenchuan Earthquake in some way?" and "What is the strategic priority of dam safety for large dams in China?" are discussed. Finally, the corresponding tactics with response to the challenge are suggested and recent preliminary progress mainly achieved in IWHR is briefly introduced.

  7. Dam design can impede adaptive management of environmental flows: a case study from the Opuha Dam, New Zealand.

    Science.gov (United States)

    Lessard, JoAnna; Hicks, D Murray; Snelder, Ton H; Arscott, David B; Larned, Scott T; Booker, Doug; Suren, Alastair M

    2013-02-01

    The Opuha Dam was designed for water storage, hydropower, and to augment summer low flows. Following its commissioning in 1999, algal blooms (dominated first by Phormidium and later Didymosphenia geminata) downstream of the dam were attributed to the reduced frequency and magnitude of high-flow events. In this study, we used a 20-year monitoring dataset to quantify changes associated with the dam. We also studied the effectiveness of flushing flows to remove periphyton from the river bed. Following the completion of the dam, daily maximum flows downstream have exceeded 100 m(3) s(-1) only three times; two of these floods exceeded the pre-dam mean annual flood of 203 m(3) s(-1) (compared to 19 times >100 m(3) s(-1) and 6 times >203 m(3) s(-1) in the 8 years of record before the dam). Other changes downstream included increases in water temperature, bed armoring, frequency of algal blooms, and changes to the aquatic invertebrate community. Seven experimental flushing flows resulted in limited periphyton reductions. Flood wave attenuation, bed armoring, and a shortage of surface sand and gravel, likely limited the effectiveness of these moderate floods. Floods similar to pre-dam levels may be effective for control of periphyton downstream; however, flushing flows of that magnitude are not possible with the existing dam infrastructure. These results highlight the need for dams to be planned and built with the capacity to provide the natural range of flows for adaptive management, particularly high flows.

  8. Geologic Hazards Associated With a Proposed Dam on the Yarlung-Tsangpo River in SE Tibet

    Science.gov (United States)

    Zeitler, P. K.; Meltzer, A. S.; Hallet, B.; Kidd, W. S.; Koons, P. O.

    2007-12-01

    For a decade anecdotes and media reports have been circulating about a proposed dam on the Yarlung- Tsangpo River in SE Tibet. The proposed site is in the deep canyon of the Yarlung-Tsangpo where the river leaves the Tibetan Plateau across an immense knickpoint, falling ~2000 m along an irregular U-shaped reach ~100 km in length. The fundamental purpose of the dam is generation of ~40,000 MW of hydropower, to be used in diverting a portion of the impounded river to water-starved regions of northern China. Offsetting benefits that would accrue from improved water supply in the north, debate has centered on the water-flow and sediment-flux impacts that would be felt downstream in the Brahmaputra system in northeastern India and Bangladesh, as well as the impact of a dam and large lake on the pristine, ecologically and ethnographically diverse area around the Yarlung-Tsangpo canyon, an area of great significance to Tibetan Buddhists. We have been examining the geodynamic evolution of eastern Tibet, and have gathered considerable geophysical and geological data on the knickpoint region. The knickpoint traverses the Namche Barwa-Gyala Peri massif, one of the most geologically active regions on Earth. In this region, very rapid bedrock exhumation at rates of 7 mm/yr or more has exposed granites as young as 1 Ma, and these rates have been ongoing for at least the past 3 m.y. Detrital-dating evidence shows that these high rates continue at present and that erosion within the massif contributes fully 50% of the suspended-sediment load in the Yarlung-Tsangpo at the point where it enters the Brahmaputra (this would be about 100 Mt/yr derived from the massif). The steep slopes in the massif fail by pervasive landsliding and suggest a steady-state topography where the high erosion rates are balanced by equivalent rates of rock uplift accommodated by numerous active structures. At a more regional scale, GPS results show that steep three-dimensional velocity gradients exist

  9. National Dam Inspection Program. Converse Lake Dam (CT 00044). Connecticut Coastal Basin, Greenwich, Connecticut. Phase I Inspection Report.

    Science.gov (United States)

    1980-02-01

    Rosenstiel Estate. S-: f. Operator - Mr. Fredrick Jansen (Estate Superintendent) (203)661-9168 -’ .g. Purpose of Dam - Recreational - The dam was originally...cut from the downstream slope of the dam by Mr. Jansen , the estate superintendent. N 4.3 MAINTENANCE OF OPERATING FACILITIES ft There is no known...a bre in the blooi’pn.Ts cn o esosn ,71 ncut drainn theo lake or e;: v.atng7 oac C" t J C n o -2 alor A’J 1 Ian toWld that a considerable flow

  10. Topographical, Geological and Geophysical Measurements in the Diamer Basha Dam Area (Gilgit-Balistan, Pakistan)

    Science.gov (United States)

    Poretti, Giorgio; Calligaris, Chiara; de Min, Gino; Tariq, Shahina; Kahn, Hawas; Zubair, Faqhia

    2010-05-01

    the whole length of the lake. The present study shows the preliminary results of an initial topographical survey of the dam's area realized within the framework of a larger monitoring project called "Nanga Parbat - Haramosh Massif Monitoring Project" the target of which is to determine the uplift of the massif due to geo-tectonic compressions. In fact northern Pakistan comprises three former distinct and previously separate plates named Karakoram, Kohistan island arc and Indian plates. They collided with each other during the Cretaceous-Tertiary ages and formed the present day configuration of this region (Himalayan orogeny) [3]. The project presented here was started in April of 2009 and developed through three different phases: a) Study of the area, contacts with the local authorities and identification of the points to be surveyed b) Monumentation of the benchmarks c) First measurement on the selected benchmarks. Since the location of the dam was very close to the Nanga Parbat-Haramosh massif It was decided to devote to it a special attention setting up a small topographical network. Three benchmarks were put on each bank (right and left) of the Indus river in order to measure the relative movements of the banks before and after the construction of the dam. The measurements were performed with a Leica TS30. Total Station following the scheme of the double parallelogram reproduced in Fig. 1 [3]. The measurements taken, before, during and after the construction of the dam will be a remarkable index of the change in the geophysical parameters produced by the dam and the related lake. References [1] http://www.paklinks.com/gs/pakistan-affairs/215216-president-musharraf-opens-work-diamer-basha-dam.html [2] http://www.defence.pk/forums/economy-development/12401-diamer-basha-dam-engineering-design-tender-documents-project-completed.html [3] http://www.dmi.units.it/~poretti/figureegubasha

  11. Route-Specific Passage Proportions and Survival Rates for Fish Passing through John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011

    Energy Technology Data Exchange (ETDEWEB)

    Ploskey, Gene R.; Weiland, Mark A.; Carlson, Thomas J.

    2012-06-04

    This report fulfills a request of the U.S. Army Engineer District, Portland, Oregon, to produce an interim report of estimates of route-specific fish passage proportions and survival rates for lower Columbia River dams in 2010 and 2011. The estimates are needed to update the Compass Model for the Columbia River Treaty and the new Biological Opinion before detail technical reports are published in late 2012. This report tabulates route-specific fish-passage proportions and survival rates for steelhead and Chinook salmon smolts passing through various sampled routes at John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011. Results were compiled from analyses of data acquired in spring 2010 and 2011 studies that were specifically designed to estimate dam-passage and forebay-to-tailrace survival rates, travel time metrics, and spill passage efficiency, as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the Columbia Basin Fish Accords. The study designs allowed for estimation of route-specific fish passage proportions and survival rates as well as estimation of forebay-passage survival, all of which are summarized herein.

  12. "Dammed Taxi Cab"--How Silent Communication in Questionnaires Can Be Understood and Used to Give Voice to Children's Experiences

    Science.gov (United States)

    Alerby, E.; Kostenius, C.

    2011-01-01

    "Dammed taxi cab"--a 12-year-old boy wrote these words in the margins of a questionnaire, and within this paper they will serve as a point of departure for the discussion of the use of questionnaires as a way to voice children's experiences. The overall aim of this paper is to enable understanding of and discuss the use of questionnaires as a way…

  13. "Dammed Taxi Cab"--How Silent Communication in Questionnaires Can Be Understood and Used to Give Voice to Children's Experiences

    Science.gov (United States)

    Alerby, E.; Kostenius, C.

    2011-01-01

    "Dammed taxi cab"--a 12-year-old boy wrote these words in the margins of a questionnaire, and within this paper they will serve as a point of departure for the discussion of the use of questionnaires as a way to voice children's experiences. The overall aim of this paper is to enable understanding of and discuss the use of questionnaires as a way…

  14. Intelligent compaction theory of high roller compacted concrete dam

    Institute of Scientific and Technical Information of China (English)

    Liu Donghai

    2012-01-01

    The concept and realization process of intelligent compaction for the construction of high roller compacted concrete dam were presented, as well as the theory of monitoring and intelligent feedback control. Based on the real-time analysis of the compaction index, a multiple regression model of the dam compactness was established and a realime estimation method of compaction quality for the entire work area of roller compacted concrete dam was proposed finally. The adaptive adjustment of the roiling process parameters was achieved, with the speed, the exciting force, the roller pass and the compaction thickness meeting the standards during the whole construction process. As a result, the compaction quality and construction efficiency can be improved. The research provides a new way for the construction quality control of roller compacted concrete dam.

  15. Study on Rock Bolt Reinforcement for a Gravity Dam Foundation

    Science.gov (United States)

    Chen, S. H.; Yang, Z. M.; Wang, W. M.; Shahrour, I.

    2012-01-01

    In this article, the rock bolt reinforcement mechanism is discussed, and the gravity method as well as the finite element method for the bolted rock is presented. These methods are applied to study the gravity dam foundation of the Xiaoxi Hydropower Project, which is influenced by the presence of a large fault with a cracked zone over 180 m wide. Rock bolt reinforcement was used to improve the stability of the dam foundation, and the reinforcement parameters were determined from a semi-empirical equation controlled by in situ test. The stability analysis was conducted using the above methods, and the improvement in terms of deformation and stress as well as stability of the dam foundation due to the reinforcement is assessed. Rock bolt reinforcement was completed successfully, and the dam started normal operations in January 2008.

  16. Parallel computation of seismic analysis of high arch dam

    Institute of Scientific and Technical Information of China (English)

    Chen Houqun; Ma Huaifa; Tu Jin; Cheng Guangqing; Tang Juzhen

    2008-01-01

    Parallel computation programs are developed for three-dimensional meso-mechanics analysis of fully-graded dam concrete and seismic response analysis of high arch dams (ADs), based on the Parallel Finite Element Program Generator (PFEPG). The computational algorithms of the numerical simulation of the meso-structure of concrete specimens were studied. Taking into account damage evolution, static preload, strain rate effect, and the heterogeneity of the meso-structure of dam concrete, the fracture processes of damage evolution and configuration of the cracks can be directly simulated. In the seismic response analysis of ADs, all the following factors are involved, such as the nonlinear contact due to the opening and slipping of the contraction joints, energy dispersion of the far-field foundation, dynamic interactions of the dam-foundation-reservoir system, and the combining effects of seismic action with all static loads. The correctness, reliability and efficiency of the two parallel computational programs are verified with practical illustrations.

  17. Geologic and field investigations Dorris Dam Modoc National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report presents the results of a. geologic and field investigation of Dorris Dam performed to evaluate embankment and foundation conditions. The work included...

  18. Elwha Master Datafile - Elwha Dam Removal - Nearshore monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Removal of two dams on the Elwha River, Washington will help restore natural sediment processes to the coastal environment near the river mouth. We are interested in...

  19. FULCRUM - A dam safety management and alert system

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Cameron; Greenaway, Graham [Knight Piesold Ltd., Vancouver, (Canada)

    2010-07-01

    Efficient management of instrumentation, monitoring and inspection data are the keys to safe performance and dam structure stability. This paper presented a data management system, FULCRUM, developed for dam safety management. FULCRUM is a secure web-based data management system which simplifies the process of data collection, processing and analysis of the information. The system was designed to organize and coordinate dam safety management requirements. Geotechnical instrumentation such as piezometers or inclinometers and operating data can be added to the database. Data from routine surveillance and engineering inspection can also be incorporated into the database. The system provides users with immediate access to historical and recent data. The integration of a GIS system allows for rapid assessment of the project site. Customisable alerting protocols can be set to identify and respond quickly to significant changes in operating conditions and potential impacts on dam safety.

  20. Will the Three Gorges Dam Stand The Test of Time?

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    After successfully containing the biggest flood this century, the Three Gorges Dam,on the upper reaches of the Yangtze River in central China’s Hubei Province, has encountered another flood, that of public opinion:Will this dam be able to hold floods that are "once-in-10,000-years" or "once-in-1,000-years" or "once-in-a-century"? Should numerous hazards this year, including land and mudslides and mountain torrents,be blamed on accumulation of sediment caused by the construction of the Three Gorges Dam? To get answers to these questions,journalists from Xinhua News Agency interviewed Cao Guangjing, Board Chairman of the China Three Gorges Corp., the operator of the Three Gorges Dam.

  1. Water quality of Flag Boshielo Dam, Olifants River, South Africa ...

    African Journals Online (AJOL)

    2013-07-24

    Jul 24, 2013 ... the dam wall coincided with the end of a drought that lasted .... was estimated by dividing the mean annual runoff by the res- ...... column was approximately holomictic. There was ... Alternatively, internal N loss associated with.

  2. Greenhouse gas emissions from Brazil’s Amazonian hydroelectric dams

    Science.gov (United States)

    Fearnside, Philip M.

    2016-01-01

    Tropical dams are often falsely portrayed as ‘clean’ emissions-free energy sources. The letter by de Faria et al (2015 Environ. Res. Lett. 10 124019) adds to evidence questioning this myth. Calculations are made for 18 dams that are planned or under construction in Brazilian Amazonia and show that emissions from storage hydroelectric dams would exceed those from electricity generation based on fossil fuels. Fossil fuels need not be the alternative, because Brazil has vast potential for wind and solar power as well as opportunities for energy conservation. Because dam-building is rapidly shifting to humid tropical areas, where emissions are higher than in other climatic zones, the impact of these emissions needs to be given proper weight in energy-policy decisions.

  3. Evaluating segregation in granular filters for earth dams

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, K. [Cambridge Univ., Cambridge (United Kingdom); Grabinsky, M. [Toronto Univ., ON (Canada)

    2003-07-01

    This paper presented some case studies to illustrate the relationship between seepage problems encountered with earth dams and segregation of the dams' granular filters during construction. A literature review of segregation mechanisms was presented along with a laboratory investigation. The case studies showed that the current understanding of the impact of a given degree of segregation is relatively poor. The literature reveals that although segregation mechanisms are identified and analyzed, very few are likely to be predominant during earth dam construction. Laboratory studies show that a mathematical relationship can be established between the filter's grain size distribution curve and the potential degree of segregation. Therefore, a mathematical relationship can also be established with the potential for adverse dam performance. The authors proposed a field procedure which allows for the monitoring of segregation during construction by contractors and engineers. It also helps in deciding whether any segregated zones require replacement. 5 refs., 7 figs.

  4. DESIGN OF SLIT DAMS FOR CONTROLLING STONY DEBRIS FLOWS

    Institute of Scientific and Technical Information of China (English)

    Hui-Pang LIEN

    2003-01-01

    A new method to a slit dam for controlling the stony debris flow has been derived based on the mass conservation law of the stony debris flow passing through a slit dam and the laboratory experiment results.This new method is then combined with three primary efficiency expressions: the dimensionless sediment outflow ratio,the sediment concentration ratio,and the sediment storage rate to develop a simple module,with which the height and the spacing of the posts,as well as the total spacing of slit dam are determined.Furthermore,these expressions can also be applied to check those slit dams that have already been constructed with their effectiveness against various magnitudes of the debris flow. The comparison between these expressions and laboratory data is in reasonable agreement.

  5. Tailings dam-break flow - Analysis of sediment transport

    Science.gov (United States)

    Aleixo, Rui; Altinakar, Mustafa

    2015-04-01

    A common solution to store mining debris is to build tailings dams near the mining site. These dams are usually built with local materials such as mining debris and are more vulnerable than concrete dams (Rico et al. 2008). of The tailings and the pond water generally contain heavy metals and various toxic chemicals used in ore extraction. Thus, the release of tailings due to a dam-break can have severe ecological consequences in the environment. A tailings dam-break has many similarities with a common dam-break flow. It is highly transient and can be severely descructive. However, a significant difference is that the released sediment-water mixture will behave as a non-Newtonian flow. Existing numerical models used to simulate dam-break flows do not represent correctly the non-Newtonian behavior of tailings under a dam-break flow and may lead to unrealistic and incorrect results. The need for experiments to extract both qualitative and quantitative information regarding these flows is therefore real and actual. The present paper explores an existing experimental data base presented in Aleixo et al. (2014a,b) to further characterize the sediment transport under conditions of a severe transient flow and to extract quantitative information regarding sediment flow rate, sediment velocity, sediment-sediment interactions a among others. Different features of the flow are also described and analyzed in detail. The analysis is made by means of imaging techniques such as Particle Image Velocimetry and Particle Tracking Velocimetry that allow extracting not only the velocity field but the Lagrangian description of the sediments as well. An analysis of the results is presented and the limitations of the presented experimental approach are discussed. References Rico, M., Benito, G., Salgueiro, AR, Diez-Herrero, A. and Pereira, H.G. (2008) Reported tailings dam failures: A review of the European incidents in the worldwide context , Journal of Hazardous Materials, 152, 846

  6. Riparian Vegetation Encroachment Ratios in rivers below large Dams

    Science.gov (United States)

    Garcia de Jalón, Diego; Martínez-Fernández, Vanesa; González del Tánago, Marta

    2017-04-01

    Large Dams and reservoirs change the natural flow regime and consequently cause many alterations in riparian vegetation dynamics which may be assessed at different spatial and temporal scales. In Mediterranean regions flow regulation is frequently associated with irrigation. Regulated rivers with this purpose very often show reduced discharges during the wet season when the reservoir is being filled and increased discharges during the dry season when irrigation takes place. This type of regulation frequently promotes riparian vegetation growth as soil moisture levels are increased during summer when a natural drought would otherwise limit its growth. Additionally, flow regulation by large dams promotes the aging of late seral riparian vegetation reducing the frequency of flood disturbance and consequently, the potential recruitment of pioneer species. In this work we study the response of woody riparian vegetation to flow regulation by large dams in four rivers from Central Spain: Jarama, Manzanares, Guadalix and Alberche. The aim is to quantify the annual vegetation encroachment ratios and to develop a model to understand the main controlling factors, such as floodplain and channel traits; flow regulation intensity; type of regulation; present vegetation canopy; distance to the dam; and time since dam commissioning. A temporal comparison using aerial photographs from 1956, 1966, 1972, 1991, 2011 and 2014 was done in thirteen river reaches downstream from large dams, to evaluate their morphological evolution.. Floodplain dimensions and channel and riparian vegetation changes were assessed by comparing different pre-dam and post-dam conditions. Recent coloured photographs with 0.5 m spatial resolution and older black-and-white photographs at 1:33 000 spatial scale were supplied by the National Geographic Institute of Spain (www.ign.es) and the Statistical Institute (www.madrid.org/nomecalles/Inicio.icm) from Madrid Community. Similar visual scales were used to cope

  7. Dam Inventory, Dams in 9 county region in South Georgia, Published in 2006, 1:2400 (1in=200ft) scale, Southern Georgia Regional Commission.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Dam Inventory dataset, published at 1:2400 (1in=200ft) scale, was produced all or in part from Field Survey/GPS information as of 2006. It is described as 'Dams...

  8. Emergy evaluation perspectives of a multipurpose dam proposal in Korea.

    Science.gov (United States)

    Kang, Daeseok; Park, Seok Soon

    2002-11-01

    The 'emergy' concept was used to evaluate the economy of Korea and the contributions of a multipurpose dam proposal to the real wealth of the Korean economy. Emergy is defined as the available energy of one kind previously used up directly and indirectly to make a product or service. The indices for Korea calculated from the emergy evaluation were close to those of developed countries. Even though its monetary balance of payments was negative in 1997, the economy of Korea showed positive balance in trade when exports and imports were expressed in emergy. The emergy evaluation showed that the Korean economy places a large stress on its environment. Water supply and generation of electricity were the most important contributions of the proposed dam in terms of emergy; 46.5 and 45.1% of the total benefit, respectively. Flood control contributed 8.4% of the total benefit. Major costs associated with the proposed dam were from sediments (33.2% of the total cost), construction services (22.8%), and social disruption of the region (21.6%). In terms of emergy, the ratio of benefits to costs of the proposed dam was 2.78 if sediments are not included, and 1.86 if sediments are included, which result in more benefits than costs in both cases. The benefit to cost ratio of the dam was larger than that of the current system (1.42) without the dam whether sediments are included in the total cost or not. The environmental stress of the proposed dam was considerably lower than that of the Korean economy, but the dam might increase stress on local environment.

  9. Liquefaction evaluation of dam foundation soils considering overlying structure

    OpenAIRE

    Gang Wang; Xing Wei; Hanlong Liu

    2015-01-01

    The liquefaction analysis procedure conducted at a dam foundation associated with a layer of liquefiable sand is presented. In this case, the effects of the overlying dam and an embedded diaphragm wall on liquefaction potential of foundation soils are considered. The analysis follows the stress-based approach which compares the earthquake-induced cyclic stresses with the cyclic resistance of the soil, and the cyclic resistance of the sand under complex stress condition is the key issue. Compr...

  10. Analysis of irreversible displacements of Daniel-Johnson dam

    Energy Technology Data Exchange (ETDEWEB)

    Chouinard, L.; Zhao, W. [McGill Univ., Montreal, PQ (Canada); Lariviere, R. [Hydro-Quebec, Montreal, PQ (Canada); Cote, P. [Hydro-Quebec Production, Baie-Comeau, PQ (Canada)

    2006-07-01

    Irreversible displacements in dams are associated with alkali-aggregate reaction, creep, and other damaging effects that compromise the safety of dams. An identification of the nature of irreversible displacements is needed to predict the future behaviour of dams as well as to select appropriate remedial measures. This paper provided details of a principal component analysis (PCA) used to investigate swelling and small irreversible displacements observed at the Daniel-Johnson dam in Quebec. PCA is a multivariate statistical method that performs the analysis of correlations or covariances between several random variables simultaneously. Three datasets were used: (1) reservoir water level; (2) air temperature; and (3) pendulum displacements. Standard linear regression analyses (HST) were performed for each variable in order to eliminate outliers and replace missing values. The multivariate dataset was then used to perform PCA on the entire dataset as well as on subsets from the original data. Displacement data from pendulums were used in the multivariate statistical analysis in which each component was treated as a separate variable. The comparison of irreversible displacements of the dam from HST analysis and principal component analysis (PCA) indicated that results were consistent with the data. The PCA analysis identified dominant patterns of behaviour and detected 2 distinct components of irreversible deformations arising from creep and swelling of concrete. Results of the study showed that the PCA analysis led to a better understanding of the overall behaviour of the dam and of individual arches and buttresses. It was concluded that the PCA analysis method will help to improve dam safety in addition to more accurately predicting the future behaviour of dams. 6 refs., 2 tabs., 9 figs.

  11. Phytoplankton composition of Sazlidere Dam lake, Istanbul, Turkey

    Directory of Open Access Journals (Sweden)

    Nese Yilmaz

    2013-05-01

    Full Text Available The phytoplankton composition of Sazlidere Dam lake was studied at 5 sampling sites between December 2003 - November 2005. A total of 67 taxa were recorded, representing Bacillariophyta (31, Chlorophyta (18, Cyanophyta (9, Chrysophyta (1, Cryptophyta (1, Dinophyta (3 and Euglenophyta (4. Bacillariophyta members constituted the dominant phytoplankton group in terms of species number. Nygaard’s compound index value and composition of phytoplankton indicate that the trophic state of Sazlidere Dam lake was changing from oligotrophic to mesotrophic.

  12. Water resource management in Japan: Forest management or dam reservoirs?

    Science.gov (United States)

    Komatsu, Hikaru; Kume, Tomonori; Otsuki, Kyoichi

    2010-01-01

    Researchers and journalists in Japan recently proposed forest management as an alternative to dam reservoir development for water resource management. To examine the validity of the proposal, we compared the potential low-flow increase due to forest clearcutting with the increase due to dam reservoir development. Here, we focused on forest clearcutting as an end member among various types of forest management. We first analyzed runoff data for five catchments and found a positive correlation between annual precipitation and the low-flow increase due to deforestation. We then examined the increase in low-flow rates due to dam reservoir development (dQ(d)) using inflow and outflow data for 45 dam reservoirs across Japan. Using the relationship between annual precipitation and the low-flow increase due to deforestation, we estimated the potential increase in the low-flow rate for each dam reservoir watershed if forests in the watershed were clearcut (dQ(f)). Only 6 of the 45 samples satisfied dQ(f)>dQ(d), indicating that the potential increase in the low-flow rate due to forest clearcutting was less than the increase due to dam reservoir development in most cases. Twenty-five of the 45 samples satisfied dQ(f)<0.2 dQ(d), indicating the potential increase in the low-flow rate due to forest clearcutting was less than 20% of the increase due to dam reservoir development in more than half the cases. Therefore, forest management is far less effective for water resource management than dam reservoir development is in Japan.

  13. Seismic stability analysis of concrete gravity dams with penetrated cracks

    Directory of Open Access Journals (Sweden)

    Shou-yan JIANG

    2012-03-01

    Full Text Available The seismic stability of a cracked dam was examined in this study. Geometric nonlinearity and large deformations, as well as the contact condition at the crack site, were taken into consideration. The location of penetrated cracks was first identified using the concrete plastic-damage model based on the nonlinear finite element method (FEM. Then, the hard contact algorithm was used to simulate the crack interaction in the normal direction, and the Coloumb friction model was used to simulate the crack interaction in the tangential direction. After verification of numerical models through a case study, the seismic stability of the Koyna Dam with two types of penetrated cracks is discussed in detail with different seismic peak accelerations, and the collapse processes of the cracked dam are also presented. The results show that the stability of the dam with two types of penetrated cracks can be ensured in an earthquake with a magnitude of the original Koyna earthquake, and the cracked dam has a large earthquake-resistant margin. The failure processes of the cracked dam in strong earthquakes can be divided into two stages: the sliding stage and the overturning stage. The sliding stage ends near the peak acceleration, and the top block slides a long distance along the crack before the collapse occurs. The maximum sliding displacement of the top block will decrease with an increasing friction coefficient at the crack site.

  14. Back analysis of mechanical parameters of roller compacted concrete dam

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam displacements.During the process of back analysis,the initial samples of parameters were designed with uniform design method.Then,a transversely isotropic model of RCCD was established by MSC.Marc software.Through this model,training samples of LSSVM model could be obtained.And then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was established.Finally,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using PLS.By inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be obtained.The example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

  15. Assessment of some heavy elements in Galma dam, Zaria, Nigeria

    Directory of Open Access Journals (Sweden)

    Butu, A.W

    2013-06-01

    Full Text Available The study was carried out to assess the levels of concentration and distribution of Pb, Cr, Fe, Cd, Co, Ni, Zn and Cu in Galma dam, Zaria, Nigeria which spanned to 35Km. The main source of data was the surface water from the lower and the upper regions of the dam. The samples were collected and prepared in the laboratory according to standard method, Atomic Absorption Spectrophotometry (AAS technique was used to analyze the data. The results showed concentration of Pb, Cr, Fe, Cd, Co, Zn and Cu at various levels and the concentration of Ni below detectable level. The results also showed the distribution of these elements at lower and upper regions of Galma dam. The enrichment of these heavy elements in the dam could be explained by the loading of the dam with debris and effluents produced by various human activities within the dam catchment area through overland and base flows and the release of elements from geologic processes. The concentration of Pb, Cr and Fe were observed to be slightly above NIS and WHO standards for drinking water. To minimize pollution of the reserviour, it is strongly recommended that there should be reduction in levels of some unhealthy practices such as indiscriminate discharge of effluents like, engine oil, lubricants, used batteries, electric bulbs/fluorescent tubes, electronic and electrical appliances and high level use of chemicals on the farms are recommended to be discouraged.

  16. Assessing Otter Presence In Dams: A Methodological Proposal

    Directory of Open Access Journals (Sweden)

    Margarida Santos-Reis

    2009-10-01

    Full Text Available Standard otter survey methodology proposed by the IUCN Otter Specialist Group enables comparisons in present/absence data in different countries or in different regions. However, otter presence and distribution assessment in dry areas, such as the Mediterranean region, which are characterized by highly marked seasonal climate with intermittent water flow coupled with different types of habitats or systems such as dams, may gain from adjustment to the methodology. Pressure for dam building still occurs in these regions and the need for studies on ecological communities and species protection is increasing. Dams are very different from usual otter riverine habitat and we need to understand their influence on otter populations. Variation of dam location, reservoir characteristics and season will all influence spraint detectability. Environmental Impact Assessment Studies and ecological studies are frequently limited by both budget and time requiring field researchers to apply more efficient methodologies. Based on experience from studies conducted in Portugal we propose adjustments to the standard survey methodology (using spraints surveying otter presence in dams to be applied specifically to Mediterranean-type ecosystems. We define aspects to be considered regarding survey season, survey length and width, number and location of survey sites, among others. This paper will allow researchers to plan more effective field surveys based on standard otter survey methodology for the purpose of dam surveys, be that to detect otter presence/absence, a more in-depth comparative studies of otter presence, or simply improving the collecting of fresh spraints for molecular spraint analysis.

  17. The Social, Historical, and Institutional Contingencies of Dam Removal

    Science.gov (United States)

    Magilligan, F. J.; Sneddon, C. S.; Fox, C. A.

    2017-06-01

    Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

  18. Ecosystem Response During the Removal of the Elwha River Dams

    Science.gov (United States)

    Pess, G. R.; McHenry, M.; Liermann, M. C.; Moses, R.; Denton, K.; McMillan, J.; Brenkman, S.; Duda, J.; Peters, R.; Anderson, J.; Quinn, T.

    2015-12-01

    Over the last century, the two dams blocked the upstream movement of anadromous fish to over 90% of the Elwha River watershed on the Olympic Peninsula of Washington State. These dams also restricted the downstream movement of sediment, wood, and other organic materials to the lower river and estuary. Populations of all Pacific salmon species and steelhead in the Elwha became critically low, habitat complexity decreased below the dams, and downstream coastal habitats became sediment starved. Simultaneous deconstruction of the two dams began in September 2011 was completed in September of 2014. The recent removal of the dams has been an opportunity to explore linkages among changes in sediment supply, salmonid populations, and ecosystem attributes. Preliminary findings focus on the delivery of millions of metric tonnes of sediment to the main river, its floodplain, and nearshore, the re-establishment of a natural wood delivery regime, the re-colonization of the upper watershed by anadromous fish, insights into functional relationships among salmonid populations and life history strategies, and the associated effects of all these elements on the aquatic and terrestrial foodwebs. This talk will provide an overview of the Elwha restoration project, and highlight recent changes observed during dam removal.

  19. The Social, Historical, and Institutional Contingencies of Dam Removal.

    Science.gov (United States)

    Magilligan, F J; Sneddon, C S; Fox, C A

    2017-02-25

    Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

  20. Effect of rubber dam on mercury exposure during amalgam removal.

    Science.gov (United States)

    Kremers, L; Halbach, S; Willruth, H; Mehl, A; Welzl, G; Wack, F X; Hickel, R; Greim, H

    1999-06-01

    It was the aim of this investigation to treat 20 volunteers with maximally 5 amalgam fillings by the same comprehensive protocol in which all removals with (n = 8) and without (n = 12) rubber dam had been performed within a few months. Nine amalgam-related parameters indicated a close matching of both groups before removal. In the group without rubber dam, mercury (Hg) levels in plasma increased significantly above preremoval values at days 1 and 3 after removal; they decreased significantly below preremoval values at day 30 in the rubber-dam group and at day 100 in both groups. Excretion rates did not increase significantly in either group, but decreased significantly at day 100 in the protected group. Peak plasma-Hg was 0.6 ng/mL on average at day one and decreased with halftimes of 3 and 43 d in subjects protected by rubber dam. The results indicated that concentrations of total mercury in plasma responded rapidly to changes in the amalgam status and reflected the actual absorption most reliably. Notably, plasma-Hg levels were sensitive enough to detect a transient attenuation of the additional exposure by using rubber dam during the removal of only a few fillings. However, being small in magnitude and lasting 100 d at best, the rubber-dam effect had minor toxicological relevance.

  1. Elwha River dam removal-Rebirth of a river

    Science.gov (United States)

    Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

    2011-01-01

    After years of planning for the largest project of its kind, the Department of the Interior will begin removal of two dams on the Elwha River, Washington, in September 2011. For nearly 100 years, the Elwha and Glines Canyon Dams have disrupted natural processes, trapping sediment in the reservoirs and blocking fish migrations, which changed the ecology of the river downstream of the dams. All five Pacific salmon species and steelhead-historically present in large numbers-are locally extirpated or persist in critically low numbers. Upstream of the dams, more than 145 kilometers of pristine habitat, protected inside Olympic National Park, awaits the return of salmon populations. As the dams are removed during a 2-3 year project, some of the 19 million cubic meters of entrapped sediment will be carried downstream by the river in the largest controlled release of sediment into a river and marine waters in history. Understanding the changes to the river and coastal habitats, the fate of sediments, and the salmon recolonization of the Elwha River wilderness will provide useful information for society as future dam removals are considered.

  2. National Dam Safety Program. Woodridge Lake Dam (MO 11005), Mississippi - Kaskaskia - St. Louis Basin, Warren County, Missouri. Phase I Inspection Report.

    Science.gov (United States)

    1979-09-01

    KASKASKIA. ST. LOUIS BAS WOODRIDGE LAKE DAM WARREN COUNTY, MISSOURI MO 11005 (9) Final rept., DACW43-79-C.-#A)75 J (i) Sep 79 (10) Walter G. /Shifrin...Dam Inspection Report National Dam Safety Program Final Report Woodridge Lake Dam (MO 11005) 6. PERFORMING ORG. REPORT NUMBER Warren County, Missouri 7...Norvell Construction of 3320 Hermoso St., St. Louis, MO. After the structure was completed, a 2 inch water- line with a water faucet was installed on the

  3. Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

    Science.gov (United States)

    Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

    2015-01-01

    The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed a hydrologic and hydraulic study to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago de Matrullas Dam, located within the headwaters of the Río Grande de Manatí. The hydrologic study yielded outflow hydrographs and peak discharges for Lago de Matrullas and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation (PMP) event, (2) a 24-hour PMP event, and (3) a 100-year-recurrence, 24-hour rainfall event. The hydraulic study simulated the hypothetical dam failure of Lago de Matrullas using hypothetical flood hydrographs generated from the hydrologic study and selected dam breach parameters. The flood wave resulting from the failure was downstream-routed through the lower reaches of the Río Matrullas, the Río Toro Negro, and the Río Grande de Manatí for determination of water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” (no precipitation) conditions. The Hydrologic Modeling System (HEC–HMS) and the River Analysis System (HEC–RAS) computer programs, developed by the Hydrologic Engineering Center (HEC) of the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was performed using the unsteady-state flow module available in the HEC–RAS model.

  4. Integrated Data-Archive and Distributed Hydrological Modelling System for Optimized Dam Operation

    Science.gov (United States)

    Shibuo, Yoshihiro; Jaranilla-Sanchez, Patricia Ann; Koike, Toshio

    2013-04-01

    In 2012, typhoon Bopha, which passed through the southern part of the Philippines, devastated the nation leaving hundreds of death tolls and significant destruction of the country. Indeed the deadly events related to cyclones occur almost every year in the region. Such extremes are expected to increase both in frequency and magnitude around Southeast Asia, during the course of global climate change. Our ability to confront such hazardous events is limited by the best available engineering infrastructure and performance of weather prediction. An example of the countermeasure strategy is, for instance, early release of reservoir water (lowering the dam water level) during the flood season to protect the downstream region of impending flood. However, over release of reservoir water affect the regional economy adversely by losing water resources, which still have value for power generation, agricultural and industrial water use. Furthermore, accurate precipitation forecast itself is conundrum task, due to the chaotic nature of the atmosphere yielding uncertainty in model prediction over time. Under these circumstances we present a novel approach to optimize contradicting objectives of: preventing flood damage via priori dam release; while sustaining sufficient water supply, during the predicted storm events. By evaluating forecast performance of Meso-Scale Model Grid Point Value against observed rainfall, uncertainty in model prediction is probabilistically taken into account, and it is then applied to the next GPV issuance for generating ensemble rainfalls. The ensemble rainfalls drive the coupled land-surface- and distributed-hydrological model to derive the ensemble flood forecast. Together with dam status information taken into account, our integrated system estimates the most desirable priori dam release through the shuffled complex evolution algorithm. The strength of the optimization system is further magnified by the online link to the Data Integration and

  5. Dam Inventory, diversion dams, Published in 2009, 1:24000 (1in=2000ft) scale, Washington County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Dam Inventory dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2009. It is described as 'diversion...

  6. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Steven G.; Muir, William D.; Marsh, Douglas M. (National Marine Fisheries Service, Northwest Fisheries Science Center, Fish Ecology Division, Seattle, WA)

    2005-10-01

    wild fish were combined in some of the analyses. Overall, the percentages for combined release groups used in survival analyses were 68% hatchery-reared yearling Chinook salmon and 32% wild. For steelhead, the overall percentages were 73% hatchery-reared and 27% wild. Estimated survival from the tailrace of Lower Granite Dam to the tailrace of Little Goose Dam averaged 0.923 for yearling Chinook salmon and 0.860 for steelhead. Respective average survival estimates for yearling Chinook salmon and steelhead were 0.875 and 0.820 from Little Goose Dam tailrace to Lower Monumental Dam tailrace; 0.818 and 0.519 from Lower Monumental Dam tailrace to McNary Dam tailrace (including passage through Ice Harbor Dam); and 0.809 and 0.465 from McNary Dam tailrace to John Day Dam tailrace. Survival for yearling Chinook salmon from John Day Dam tailrace to Bonneville Dam tailrace (including passage through The Dalles Dam) was 0.735. We were unable to estimate survival through this reach for steelhead during 2004 because too few fish were detected at Bonneville Dam due to operation of the new corner collector at the second powerhouse. Combining average estimates from the Snake River smolt trap to Lower Granite Dam, from Lower Granite Dam to McNary Dam, and from McNary Dam to Bonneville Dam, estimated annual average survival through the entire hydropower system from the head of Lower Granite reservoir to the tailrace of Bonneville Dam (eight projects) was 0.353 (s.e. 0.045) for Snake River yearling Chinook salmon. We could not empirically estimate survival through the entire system for steelhead in 2004 because of low detection rates for this species at Bonneville Dam. For yearling spring Chinook salmon released in the Upper Columbia River, estimated survival from point of release to McNary Dam tailrace was 0.484 (s.e. 0.005) for fish released from Leavenworth Hatchery, 0.748 (s.e. 0.015) for fish released from Entiat Hatchery, 0.738 (s.e. 0.036) for fish released from Winthrop Hatchery

  7. Qu'Appelle River Dam, dam break analysis using advanced GIS tools for rapid modelling and inundation mapping

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, D. [Hatch Energy, Winnipeg, MB (Canada); Campbell, C. [Saskatchewan Watershed Authority, Moose Jaw, SK (Canada); Groeneveld, J. [Hatch Energy, Calgary, AB (Canada)

    2008-07-01

    The South Saskatchewan River Project (SSRP) comprises a multi-purpose reservoir that provides water for conservation and irrigation, flood control, power generation, recreation, and municipal and industrial water supply. In addition to the 64 m high Gardiner Dam, the 27 m high Qu'Appelle River Dam and the 22 km long Lake Diefenbaker Reservoir, the SSRP also includes ancillary works. The Qu'Appelle River valley extends for 458 km before connecting to the Assiniboine River. The valley is incised up to 90 m in depth and is a popular cottaging and recreational area with several major communities located in the flood plain. In the event of a breach of the Qu'Appelle Dam, the discharge will increase from a normal maximum discharge of under 60 m{sup 3} per second to over 50,000 m{sup 3} per second. The Saskatchewan Watershed Authority (SWA) is responsible for ensuring safe development of the Province's water resources, without affecting reservoir or lake operations, and preventing damage from flooding, erosion or land slides. It is in the process of developing Hazard Assessments and emergency preparedness plans for each of their dams in accordance with the Canadian Dam Safety Guidelines. Studies using GIS technology and the hydrodynamic routing model HEC-RAS have been completed to evaluate the potential inundation that may result in the event of failure of the Qu'Appelle River Dam. These studies involved the development of a breach parameter model using a breach data set revised to better reflect the Qu'Appelle River Dam; the development of a dam break model for the Qu'Appelle River Dam and downstream river and flood plain; and, the use of this model to simulate two potential dam failure scenarios for the Qu'Appelle River Dam, notably failure during passage of the PMF and failure during fair weather conditions. Inundation maps have been prepared for the downstream Qu'Appelle River valley for each of the above events. 3 refs., 4

  8. Dam that social networking: connecting South Africa's major dams to social media

    CSIR Research Space (South Africa)

    Butgereit, L

    2011-10-01

    Full Text Available , embarrassingly so, a marital bed. 2. Research Question and Methodology The data provided by the South African Department of Water Affairs is excellent and accurate [4, 5]. Unfortunately, the majority of South Africans are not aware of the data which... provides a nice fly-in approach to viewing the Vaal Dam. The data provided in the description field of the KML is reproduced in the side bar. 5. Twitter All communication with Twitter was done via the Twitter4J library. Twitter4J is a Java...

  9. Review of revised Klamath River Total Maximum Daily Load models from Link River Dam to Keno Dam, Oregon

    Science.gov (United States)

    Rounds, Stewart A.; Sullivan, Annett B.

    2013-01-01

    Flow and water-quality models are being used to support the development of Total Maximum Daily Load (TMDL) plans for the Klamath River downstream of Upper Klamath Lake (UKL) in south-central Oregon. For riverine reaches, the RMA-2 and RMA-11 models were used, whereas the CE-QUAL-W2 model was used to simulate pooled reaches. The U.S. Geological Survey (USGS) was asked to review the most upstream of these models, from Link River Dam at the outlet of UKL downstream through the first pooled reach of the Klamath River from Lake Ewauna to Keno Dam. Previous versions of these models were reviewed in 2009 by USGS. Since that time, important revisions were made to correct several problems and address other issues. This review documents an assessment of the revised models, with emphasis on the model revisions and any remaining issues. The primary focus of this review is the 19.7-mile Lake Ewauna to Keno Dam reach of the Klamath River that was simulated with the CE-QUAL-W2 model. Water spends far more time in the Lake Ewauna to Keno Dam reach than in the 1-mile Link River reach that connects UKL to the Klamath River, and most of the critical reactions affecting water quality upstream of Keno Dam occur in that pooled reach. This model review includes assessments of years 2000 and 2002 current conditions scenarios, which were used to calibrate the model, as well as a natural conditions scenario that was used as the reference condition for the TMDL and was based on the 2000 flow conditions. The natural conditions scenario included the removal of Keno Dam, restoration of the Keno reef (a shallow spot that was removed when the dam was built), removal of all point-source inputs, and derivation of upstream boundary water-quality inputs from a previously developed UKL TMDL model. This review examined the details of the models, including model algorithms, parameter values, and boundary conditions; the review did not assess the draft Klamath River TMDL or the TMDL allocations

  10. National Program for Inspection of Non-Federal Dams. Nichols Pond Dam (VT 00184), Richelieu River Basin, Woodbury, Vermont. Phase I Inspection Report.

    Science.gov (United States)

    1980-04-01

    on pages B-12 through B-14. A letter report by ’fr. Barranco describes some of the history on page B-15. 3. Plans and sketches prepared by DuBois...Peter Barranco , Jr., P.E., Dam Safety Engineer I Subject: Nichols Pond Dam - Woodbury (252-1) The writer inspected subject dam, obtained dimensions and

  11. 5. decennial inspection of Tignes dam. Draining of the higher french dam; 5. inspection decennale du barrage de Tignes. Vidange du plus haut barrage de France

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This document deals with the 5. decennial inspection of the Tignes dam. The Tignes dam has been drained to allow EDF and the public authorities to verify the dam wall, of 180 m high, in order to validate the next decade. The four steps of the drainage are described as the maintenance policy of such building. (A.L.B.)

  12. Simulation of the thermal behaviour of a concrete dam using in situ measurements : case of Daniel-Johnson dam

    Energy Technology Data Exchange (ETDEWEB)

    Thibeault, N. [Tecsult Inc., Montreal, PQ (Canada); Lariviere, R. [Hydro-Quebec, Montreal, PQ (Canada)

    2004-09-01

    The Daniel-Johnson Dam is the largest multiple-arch dam in the world. It was completed in 1969 at a height of 214 metres. The dam has faced many challenges related to severe thermal conditions, presence of plunging cracks in many arches and opening at the rock-concrete interface. Major concerns lie with the shear resistance in the plane of the plunging cracks. It has been determined that the main cause of arch degradation is related to the thermal behaviour of the dam. A thermal shelter was therefore constructed in the lower part of the arches. This protection has proved to be very effective. A decision was later taken to grout the plunging cracks of some arches. This involved the verification of the structural stability of the arch base. To accomplish this, the shear safety factor during the proposed injection had to be validated. This paper discussed the complex challenge of simulating the thermal behaviour of a concrete dam. It presented an alternative to the conventional methods to implement a thermal profile in a finite element model. Synthetic curves of the thermal profile were used for different thicknesses and boundary conditions. The curves were then interpolated for intermediate thicknesses. A numerical model developed for this project has been verified according to the recommendations of Bulletin 94 of ICOLD (Computer Software for Dams). The loads to consider within the framework study of the Daniel-Johnson Dam gravity; thermal gradient in summer and winter; thermal protection; hydrostatic pressure; uplift pressure in cracks; hydrostatic pressure at upstream on the grout curtain; rock-concrete contact opening; and grout pressures. The proposed method has proven to be simple, efficient and easily implemented to rapidly determine the thermal behaviour of the structures. It is also particularly well suited for multiple-arch dams. The thermal structure analysis was used to determine deformation which was compared with measurements of the pendulums. 8 refs

  13. 基于坝基水泥土防渗的希尼尔水库大坝渗流分析%Seepage analysis of Xi'ni'er reservoir dam with cement soil at dam foundation

    Institute of Scientific and Technical Information of China (English)

    魏光辉

    2015-01-01

    Seepage monitoring is an significant content of reservoir dam safety monitoring, and the result is important for guiding dam operation. Taking Xi'ni'er reservoir main dam cement soil cutoff wall sec⁃tion as an example, this paper analyzes the seepage of typical section 4+575 and 5+175. The results show that seepage water level and osmotic pressure at dam foundation of these two sections are high, so are dam water level and the elevation of escaping point of backfill base material downstream;horizontal seepage gradient of dam foundation at drainage ditch is relatively large, slightly less than permissible gradient of dam foundation soil but bigger than filter material's, which means potential safety hazards. The results provide important reference for guiding the safe operation of reservoir.%渗流监测是水库大坝安全监测的一项重要内容,其结果对于指导大坝的安全运行管理有着重要意义。以希尼尔水库主坝水泥土防渗墙段为例,对主坝典型断面4+575与5+175进行渗流分析,结果表明:上述两处断面在高库水运行期坝基渗压水位高、渗透压力较大,坝体水位及下游坝后回填清基料出逸点高程较高;排水沟处坝基水平向渗透坡降较大,稍小于坝基土体的允许渗透坡降,并超过反滤垫层料的允许渗透坡降,存在渗流安全隐患。研究结果为指导水库的安全运行提供了重要参考。

  14. 关于混凝土重力坝断面设计的探讨%Discussions on cross-section design of concrete gravity dam

    Institute of Scientific and Technical Information of China (English)

    李晶; 贾金生; 汪洋; 杨会臣

    2013-01-01

    The problems from failures of concrete gravity dam are briefly reviewed herein,and then the theoretical formula for the reasonable cross-section of gravity dam is derived and analyzed.Furthermore,the reasons why the isosceles triangular cross-section is adopted for the cement-sand-gravel dam and why the cross-secion of gravity dam in japan is a little bit too larger and its upstream is designed with a fold-slope are illustrated,while the differences among the cross-sections designed for the super-high gravity dams with the heights over 200 m at home and abroad are comparatively analyzed.Based on the relevant analysis,it is pointed out that not only the study on the dam stability against sliding is necessary to be deepened in China,but the relevant design criteria for the high dams with the heights over 200 m are also necessary to be deepened.%简要综述了混凝土重力坝的溃坝问题,推导并分析了重力坝合理断面理论公式,简述了胶凝砂砾石坝采用等腰三角型断面、日本重力坝断面偏大以及上游采用折坡设计等原因,分析比较了200 m以上特高重力坝国内外设计的断面差别.基于分析,指出我国重力坝需基于观测进一步深化大坝抗滑稳定研究,对于200 m以上高坝,则需进一步深化设计准则的探讨.

  15. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species.

    Directory of Open Access Journals (Sweden)

    Stephan T Leu

    Full Text Available Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantially active on more days (days with >100 steps, and moved more steps per day compared to lizards that did not have access to the dam, both during the early and late period of our observation. Furthermore, while the two groups of lizards had similar body condition early in the season, they differed later in the season. Lizards with dam access retained, whereas lizards without access lost body condition. Local heterogeneity in access to an artificial water resource resulted in spatially dependent behavioural variation among sleepy lizard individuals. This suggests that sleepy lizards have flexible responses to changing climatic conditions, depending on the availability of water. Furthermore, while reducing activity appears a suitable short term strategy, if harsh conditions persist, then access to dams could be of substantial benefit and could support sustained lizard activity and movement and allow maintenance of body condition. Hence, artificial watering points, such as the dams constructed by pastoralists, may provide local higher quality refugia for sleepy lizards and other species during drought conditions.

  16. Artificial Water Point for Livestock Influences Spatial Ecology of a Native Lizard Species.

    Science.gov (United States)

    Leu, Stephan T; Bull, C Michael

    2016-01-01

    Pastoralism is a major agricultural activity in drier environments, and can directly and indirectly impact native species in those areas. We investigated how the supply of an artificial watering point to support grazing livestock affected movement and activity patterns of the Australian sleepy lizard (Tiliqua rugosa) during a drought year. We observed 23 adult lizards; six had access to a dam, whereas 17 lizards did not. Lizards with access to the dam had larger home ranges, were substantially active on more days (days with >100 steps), and moved more steps per day compared to lizards that did not have access to the dam, both during the early and late period of our observation. Furthermore, while the two groups of lizards had similar body condition early in the season, they differed later in the season. Lizards with dam access retained, whereas lizards without access lost body condition. Local heterogeneity in access to an artificial water resource resulted in spatially dependent behavioural variation among sleepy lizard individuals. This suggests that sleepy lizards have flexible responses to changing climatic conditions, depending on the availability of water. Furthermore, while reducing activity appears a suitable short term strategy, if harsh conditions persist, then access to dams could be of substantial benefit and could support sustained lizard activity and movement and allow maintenance of body condition. Hence, artificial watering points, such as the dams constructed by pastoralists, may provide local higher quality refugia for sleepy lizards and other species during drought conditions.

  17. Combating Poverty by Irrigation from Large Dams in Arid Countries: A Case Study of Minab Dam, Iran

    Directory of Open Access Journals (Sweden)

    ALI ASGHAR IRAJ POOR

    2010-10-01

    Full Text Available A set of indicators for sustainable development were identified to be employed in developing countries. The selected indicators provided a good understanding of social and engineering outputs of a water resources project. Results of the study revealed that there are significant positive impacts of dam construction but they were not same as the targeted objectives envisaged in the feasibility report of the project. It means that after construction of the dam and irrigation system, development didn?t match with the targeted goals of the project. This study argues the world-wide controversy against construction of dam in arid zone which is ill-founded and based on a few short term, mitigable negative impacts, ignoring many positive long term inputs alleviating chronic poverty in arid regions. The study meticulously looks into the pre dam bio-physical and socio-economic conditions in one of the arid region of Iran under the area commanded by Minab dam. This dam was constructed in Hormozgan province of Iran in 1983 and its irrigation system was completed in 1986 which was followed by progressive expansion of irrigated agriculture which almost doubled in year 2006. Literacy rate has increased from 41% (pre-project to 74% in 2006. Similarly, significant improvements were observed in health care, sanitation, education, and other disciplines.

  18. Case Study of the Chaq-Chaq Dam Failure: Parameter Estimation and Evaluation of Dam Breach Prediction Models

    Directory of Open Access Journals (Sweden)

    Dr. KawaZedanAbdulrahman

    2014-05-01

    Full Text Available On 4th of February, 2006 at about 10:00 pm.Chaq-Chaq dam failed due to overtopping. The fall of 131.2 mm of rain over a 24-hour period was recorded at Sulaimani metrological gage station, which is located about 7.5Kmsouth-east of the dam. As a result, the reservoir level rose, the dam has been overtopped and finally breached near the spillway at the right abutment. Fortunately no human lives loss nor important structure destruction were reporteddue to the dam failure. The aim of this paper is to estimate the flood hydrograph passing through Chaq-Chaq dam breach using measured breach geometry as input to unsteady option of HEC RAS 4.1.0 and calibrating the breach formation time to obtain the measured maximum water surface at Chaq-Chaq Bridge (1.36 km downstream of dam axis. In addition the recent breach prediction models were evaluated to check their accuracy in predicting the breach geometry, breach formation time and peak breach discharge.

  19. Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, Mark; Scholz, Allan; McLellan, Holly [Eastern Washington University Department of Biology; Olson, Jason [Kalispel Tribe of Indians Natural Resources Department

    2009-07-13

    This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acoustic radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other

  20. Impact of dam construction on river banks evolution and sediment dynamics. A case study from the Po River (Italy).

    Science.gov (United States)

    Maselli, V.; Pellegrini, C.; Crose, L.; Del Bianco, F.; Mercorella, A.

    2014-12-01

    Rivers draining densely populated landscapes are extremely impacted by modern human engineering: armored beds, artificial levees and dams modified natural fluvial dynamics, and consequently, the evolution of alluvial plains, deltas and coastal environments. Dams, in particular, segmented the longitudinal continuity of the river and reduced (or even interrupted) the export of sediment toward the sea. Here we investigate the impact of the Isola Serafini dam on the upstream portion of the Po River (Italy) influenced by backwater, by using an integrated approach of aerial and satellite images, longitudinal cross-sections, grain size analysis, backscatter data and multibeam bathymetry. The analysis of aerial photographs, acquired every 10 yr since the dam construction in 1960, and of longitudinal cross-sections, allows understanding how the river adjusts its profile in response to the backwater and quantifying areas of net river banks erosion and deposition in meanders. The drowning of the reaches influenced by backwater reduced the progradation of point bars and promoted the deposition of fine grained sediments, as highlighted by grain size analysis on surficial sediment sampled across and along the river course. Calibrated back-scatter data with grain-size distributions of two selected meanders, under the backwater effect and beyond, show how sands are progressively replaced by fine-grained sediments in the meander belt and in the river axis, mainly reflecting the reduction of flow velocity, inferred also by river bed roughness. The understanding of river and sediment dynamics under the influence of backwater due to dam construction is useful when studying pristine systems in which natural backwater affects their evolution, as in the case of the formation of standing water bodies during the drowning of an incised valley.

  1. ONE- AND TWO-DIMENSIONAL COUPLED HYDRODYNAMICS MODEL FOR DAM BREAK FLOW

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1-D and 2-D mathematical models for dam break flow were established and verified with the measured data in laboratory. The 1-D and 2-D models were then coupled, and used to simulate the dam break flow from the reservoir tail to the dam site, the propagation of dam break waves in the downstream channel, and the submergence of dam break flow in the downstream town with the hydrodynamics method. As a numerical example, the presented model was employed to simulate dam break flow of a hydropower station under construction. In simulation, different dam-break durations, upstream flows and water levels in front of dam were considered, and these influencing factors of dam break flow were analyzed, which could be referenced in planning and designing hydropower stations.

  2. Evaluation of surface properties and atmospheric disturbances caused by post-dam alterations of land use/land cover

    Science.gov (United States)

    Woldemichael, A. T.; Hossain, F.; Pielke, R., Sr.

    2014-09-01

    This study adopted a differential land-use/land-cover (LULC) analysis to evaluate dam-triggered land-atmosphere interactions for a number of LULC scenarios. Two specific questions were addressed: (1) can dam-triggered LULC heterogeneities modify surface and energy budget, which, in turn, change regional convergence and precipitation patterns? (2) How extensive is the modification in surface moisture and energy budget altered by dam-triggered LULC changes occurring in different climate and terrain features? The Regional Atmospheric Modeling System (RAMS, version 6.0) was set up for two climatologically and topographically contrasting regions: the American River watershed (ARW), located in California, and the Owyhee River watershed (ORW), located in eastern Oregon. For the selected atmospheric river precipitation event of 29 December 1996 to 3 January 1997, simulations of three pre-defined LULC scenarios are performed. The definition of the scenarios are (1) the "control" scenario, representing the contemporary land use, (2) the "pre-dam" scenario, representing the natural landscape before the construction of the dams and (3) the "non-irrigation" scenario, representing the condition where previously irrigated landscape in the control is transformed to the nearby land-use type. Results indicated that the ARW energy and moisture fluxes were more extensively affected by dam-induced changes in LULC than the ORW. Both regions, however, displayed commonalities in the modification of land-atmosphere processes due to LULC changes, with the control-non-irrigation scenario creating more change than the control-pre-dam scenarios. These commonalities were: (1) the combination of a decrease in temperature (up to 0.15 °C) and an increase at dew point (up to 0.25 °C) was observed; (2) there was a larger fraction of energy partitioned to latent heat flux (up to 10 W m-2) that increased the amount of water vapor in the atmosphere and resulted in a larger convective available

  3. Microtremor response of the Cheongcheon dam in Korea

    Science.gov (United States)

    Kim, Ki Young; Park, Young-Gyu

    2016-04-01

    Microtremors were analysed using the reference-dependent horizontal spectral (H/H) method and the horizontal-to-vertical spectral ratio (H/V) method to estimate site effects of the Cheongcheon earthen dam in Korea. Seismic vibrations were recorded on the dam's crest, at the toe of the dam, and in a downstream borehole using three-component accelerometers. The H/H peaks for crest versus toe-of-dam accelerations occurred at 3.1, 6.7 and 13.1 Hz with ratios of 6.9, 11.4 and 8.9, respectively. The H/V peaks for the crest of the dam occurred at 3.0, 7.0 and 13.4 Hz with ratios of 6.7, 7.8 and 5.6, respectively. The peak near 3 Hz may correspond to depth to bedrock, whereas the other peaks at higher frequencies may reflect the geometrical effect of the dam or overtone responses to the thickness of dam fill overlying the clay core. For the toe data, from the H/V spectral ratio method, the basement boundary appeared as double peaks near 8 and 10 Hz with corresponding amplification factors of 5.2 and 6.2. These may indicate a gradual change in velocity across the basement boundary at ~10 m depth. The third resonance, which occurred at 15 Hz, may correlate with the refraction boundary at 5-6 m depth in the overburden layer. Both the frequencies and magnitudes of resonance derived from the H/H and H/V methods are reasonably well matched to the theoretical response curves computed by the reflection and transmission matrix and the two-dimensional finite difference methods.

  4. The behaviour of a large dam at severe frost

    Directory of Open Access Journals (Sweden)

    M. C. SPADEA

    1972-06-01

    Full Text Available Synthesizing the problem, the action of the thrusts in the
    behaviour of t h e dam of Pieve di Cadore, makes itself conspicuous expecially
    during three periods of the year:
    1. - About the end of June, the air temperature, 011 t h e average, overcomes
    the water one in the watershed upstream the dam: the bending of
    t h e dam upstream increases from the bottom to the top.
    2. - About the end of October, the thermal conditions change; the
    mean air temperature grows lower than the mean water temperature; the
    dam begins her bending dowstream.
    3. - When the air temperature is distinctly below 0 °C, the action of
    t h e t h r u s t s grows more complexe; t h e rocky waterlogged system downstream
    of t h e dam, while cooling, swells and pushes t h e bottom of t h e dam upstream;
    at t h e higher quote, on the contrary, the t h r u s t downstream continues.
    When the strenght limit of the medium is surpassed, arises a contrast
    between the rocky system and the concrete structure: this contrast can origin
    a t e very small fractures, revealed from seismic station installed into the
    central ashlar (XIV a t 660 metres height of t h e dam, under t h e form of microshocks
    which energy is of about 10I0-10U erg.

  5. Dam foundation excavation techniques in China:A review

    Institute of Scientific and Technical Information of China (English)

    Yuzhu Zhang; Wenbo Lu; Ming Chen; Peng Yan; Yingguo Hu

    2013-01-01

    A protective layer (PL) is commonly reserved above foundation surface to protect the underlying rock mass during dam foundation excavation. In China, the PL of dam foundation is conventionally subdivided into two or three thin layers and excavated with the shallow-hole blasting method, even by pneumatic pick method in case of soft rock mass. The aforementioned layered excavation of the PL delays the con-struction of the whole project. After nearly 30-year practices, several safe and efficient methods for the PL excavation of dam foundation are gradually developed. They include shallow-hole bench blasting with cushion material (SBC) at the bottom of the hole, and horizontal smooth blasting (HSB). The PL is even can-celled on the condition that horizontal pre-split technique is employed during dam foundation excavation. This paper introduces the aforementioned two PL excavation methods (shallow-hole blasting and bench blasting) and horizontal pre-split technique of dam foundation without protective layer (HPP). The basic principles of blasting method, blasting geometry, charge structure, drill-and-blast parameters of typical projects are examined. Meanwhile, the merits and limitations of each method are compared. Engineering practices in China show that HSB is basically the optimal method for dam foundation PL excavation in terms of foundation damage control and rapid construction. Some new problems for dam foundation PL excavation arising, such as strong unloading and relaxation phenomenon that encountered in the gorge region of southwest China, are needed to be addressed; and the corresponding countermeasures are discussed as well.

  6. Bathymetric survey of the Brandon Road Dam Spillway, Joliet, Illinois

    Science.gov (United States)

    Engel, Frank; Krahulik, Justin

    2016-01-01

    Bathymetric survey data of the Brandon Road Dam spillway was collected on May 27 and May 28, 2015 by the US Geological Survey (USGS) using Trimble Real-Time Kinematic Global Positioning System (RTK-GPS) equipment. The base station was set up over a temporarily installed survey pin on both days. This pin was surveyed into an existing NGS benchmark (PID: BBCN12) within the Brandon Road Lock property. In wadeable sections, a GPS rover with 2.0 meter range pole and flat-foot was deployed. In sections unable to be waded, a 2.0 meter range pole was fix-mounted to a jon boat, and a boat-mounted Acoustic Doppler Current Profiler (ADCP) was used to collect the depth data. ADCP depth data were reviewed in the WinRiver II software and exported for processing with the Velocity Mapping Toolbox (Parsons and others, 2013). The RTK-GPS survey points of the water surface elevations were used to convert ADCP-measured depths into bed elevations. An InSitu Level Troll collected 1-minute water level data throughout the two day survey. These data were used to verify that a flat-pool assumption was reasonable for the conversion of the ADCP data to bed elevations given the measurement precision of the ADCP. An OPUS solution was acquired for each survey day.Parsons, D. R., Jackson, P. R., Czuba, J. A., Engel, F. L., Rhoads, B. L., Oberg, K. A., Best, J. L., Mueller, D. S., Johnson, K. K. and Riley, J. D. (2013), Velocity Mapping Toolbox (VMT): a processing and visualization suite for moving-vessel ADCP measurements. Earth Surf. Process. Landforms, 38: 1244–1260. doi: 10.1002/esp.3367

  7. Dams. Bulletin of the technical service of electric power and big dams; Barrages. Bulletin du service technique de l`energie electrique et des grands barrages

    Energy Technology Data Exchange (ETDEWEB)

    Davard, J.

    1997-12-31

    The Dams bulletin reports on technical news concerning big French dams in operation. This issue comprises 5 papers. Two of them are examples of granting problems which led to the dismantling of the dams of Kernansquillec (Cotes d`Armor, France) and Maisons-Rouges (Indre-et-Loire, France) for economical and environmental reasons. The 3 other papers concern the life of French dams (technical control reports of the French dams in operation), the activities of the control service (annual inspections, preparation of draining operations, renewing of granting), and some general information (organisation of competent authorities, colloquium reports, hydro-power production during the first quarter of 1997). (J.S.)

  8. Large Dam Effects on Flow Regime and Hydraulic Parameters of river (Case study: Karkheh River, Downstream of Reservoir Dam

    Directory of Open Access Journals (Sweden)

    Farhang Azarang

    2017-06-01

    Full Text Available Introduction: The critical role of the rivers in supplying water for various needs of life has led to engineering identification of the hydraulic regime and flow condition of the rivers. Hydraulic structures such dams have inevitable effects on their downstream that should be well investigated. The reservoir dams are the most important hydraulic structures which are the cause of great changes in river flow conditions. Materials and Methods: In this research, an accurate assessment was performed to study the flow regime of Karkheh river at downstream of Karkheh Reservoir Dam as the largest dam in Middle East. Karkheh River is the third waterful river of Iran after Karun and Dez and the third longest river after the Karun and Sefidrud. The Karkheh Dam is a large reservoir dam built in Iran on the Karkheh River in 2000. The Karkheh Reservoir Dam is on the Karkheh River in the Northwestern Khouzestan Province, the closest city being Andimeshk to the east. The part of Karkheh River, which was studied in this research is located at downstream of Karkheh Reservoir Dam. This interval is approximately 94 km, which is located between PayePol and Abdolkhan hydrometric stations. In this research, 138 cross sections were used along Karkheh River. Distance of cross sections from each other was 680m in average. The efficient model of HEC-RAS has been utilized to simulate the Karkheh flow conditions before and after the reservoir dam construction using of hydrometric stations data included annually and monthly mean discharges, instantaneous maximum discharges, water surface profiles and etc. Three defined discharges had been chosen to simulate the Karkheh River flow; maximum defined discharge, mean defined discharge and minimum defined discharge. For each of these discharges values, HEC-RAS model was implemented as a steady flow of the Karkheh River at river reach of study. Water surface profiles of flow, hydraulic parameters and other results of flow regime in

  9. The Distribution and Flux of Fish in the Forebay of The Dalles Dam in 2003

    Energy Technology Data Exchange (ETDEWEB)

    Faber, Derrek M.; Hanks, Michael E.; Zimmerman, Shon A.; Skalski, John R.; Dillingham, Peter W.

    2005-04-29

    In spring and summer 2003, the Pacific Northwest National Laboratory led a team that conducted mobile and fixed hydroacoustic surveys in the forebay of The Dalles Dam for the U.S. Army Corps of Engineers - Portland District, for the Anadromous Fish Evaluation Program. The surveys provided information on the distribution and movement of smolt-sized fish relative to ambient factors such as flow, bathymetry, or diel cycle in the forebay at The Dalles Dam. This information is intended to provide baseline data for the development of a surface bypass alternative for juvenile salmon at The Dalles Dam. We sampled the forebay of The Dallas Dam one day and night each week for six weeks in the spring and another six weeks in the summer. In general, during the day in the spring, the greatest densities of smolt-sized fish were observed in the thalweg of the main channel from the Washington bank, to the east side of the powerhouse, along the powerhouse, and concentrated in the areas next to the sluiceway. Fish density was lower on the Washington side of the river and west of mid-powerhouse (north spillway side). The spring night distribution was similar, with a few notable differences. The density of fish was high on the east side of the powerhouse and along the face of the powerhouse, and more fish were detected on the north spillway side. The distribution of sub-yearling sized fish in summer followed the same general patterns as spring, except that summer fish had a greater presence on the east side of the powerhouse and on the north spillway side. The vertical distribution of fish was also determined. In spring 80% of fish were above 5.6 m of depth during the day and above 4.7 m in the night. The summer fish were similarly distributed in the day and night with 80% of the fish in the upper 4.5 m and 4.7 m of the water column respectively. In general the smolt-sized fish were distributed deeper in the water column in the center of the channel than near the edges. The net

  10. Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management

    Science.gov (United States)

    Buccola, Norman L.; Rounds, Stewart A.; Sullivan, Annett B.; Risley, John C.

    2012-01-01

    Detroit Dam was constructed in 1953 on the North Santiam River in western Oregon and resulted in the formation of Detroit Lake. With a full-pool storage volume of 455,100 acre-feet and a dam height of 463 feet, Detroit Lake is one of the largest and most important reservoirs in the Willamette River basin in terms of power generation, recreation, and water storage and releases. The U.S. Army Corps of Engineers operates Detroit Dam as part of a system of 13 reservoirs in the Willamette Project to meet multiple goals, which include flood-damage protection, power generation, downstream navigation, recreation, and irrigation. A distinct cycle in water temperature occurs in Detroit Lake as spring and summer heating through solar radiation creates a warm layer of water near the surface and isolates cold water below. Controlling the temperature of releases from Detroit Dam, therefore, is highly dependent on the location, characteristics, and usage of the dam's outlet structures. Prior to operational changes in 2007, Detroit Dam had a well-documented effect on downstream water temperature that was problematic for endangered salmonid fish species, releasing water that was too cold in midsummer and too warm in autumn. This unnatural seasonal temperature pattern caused problems in the timing of fish migration, spawning, and emergence. In this study, an existing calibrated 2-dimensional hydrodynamic water-quality model [CE-QUAL-W2] of Detroit Lake was used to determine how changes in dam operation or changes to the structural release points of Detroit Dam might affect downstream water temperatures under a range of historical hydrologic and meteorological conditions. The results from a subset of the Detroit Lake model scenarios then were used as forcing conditions for downstream CE-QUAL-W2 models of Big Cliff Reservoir (the small reregulating reservoir just downstream of Detroit Dam) and the North Santiam and Santiam Rivers. Many combinations of environmental, operational, and

  11. Experiences from the small historical dams failures during heavy floods

    Science.gov (United States)

    Vaníček, I.; Vaníček, M.; Jirásko, D.; Pecival, T.

    2015-09-01

    Roughly between 400 and 600 years ago many small earth dams were constructed mainly in the south part of the Czech Republic. They were used for fish production and flood protection. To our days roughly one third survived, which means about 25 000 of them. During catastrophic floods in 2002 many of them had some problems but less than 0.3% failed. Experiences gained from the failure evaluation are presented. Firstly from the view of limit states of failures, when limit states of internal erosion and surface erosion played most important role and were the main reason of failures. Secondly, from the view of so called domino effect of failure, when the most important dam on the catchment basin failed and after that the other ones, situated below, had limited chance to survive. The failures are described for catchment basin of the small river Lomnice in south part of the Czech Republic close to the town Blatna. The experiences obtained there led to the evaluation of other catchment basins where domino effect of failure can play also very important role. For the evaluation of potential risk, the numerical modelling was used to study the flood wave propagation below the critical dam, especially at the moment when this wave is reaching the dam situated below the critical one. Finally, the recommendations are specified, not only for individual dams but also for catchment basin, where the risk of domino effect failure is very high.

  12. Geophysical investigation of seepage beneath an earthen dam.

    Science.gov (United States)

    Ikard, S J; Rittgers, J; Revil, A; Mooney, M A

    2015-01-01

    A hydrogeophysical survey is performed at small earthen dam that overlies a confined aquifer. The structure of the dam has not shown evidence of anomalous seepage internally or through the foundation prior to the survey. However, the surface topography is mounded in a localized zone 150 m downstream, and groundwater discharges from this zone periodically when the reservoir storage is maximum. We use self-potential and electrical resistivity tomography surveys with seismic refraction tomography to (1) determine what underlying hydrogeologic factors, if any, have contributed to the successful long-term operation of the dam without apparent indicators of anomalous seepage through its core and foundation; and (2) investigate the hydraulic connection between the reservoir and the seepage zone to determine whether there exists a potential for this success to be undermined. Geophysical data are informed by hydraulic and geotechnical borehole data. Seismic refraction tomography is performed to determine the geometry of the phreatic surface. The hydro-stratigraphy is mapped with the resistivity data and groundwater flow patterns are determined with self-potential data. A self-potential model is constructed to represent a perpendicular profile extending out from the maximum cross-section of the dam, and self-potential data are inverted to recover the groundwater velocity field. The groundwater flow pattern through the aquifer is controlled by the bedrock topography and a preferential flow pathway exists beneath the dam. It corresponds to a sandy-gravel layer connecting the reservoir to the downstream seepage zone.

  13. Applying Mechanistic Dam Breach Models to Historic Levee Breaches

    Directory of Open Access Journals (Sweden)

    Risher Paul

    2016-01-01

    Full Text Available Hurricane Katrina elevated levee risk in the US national consciousness, motivating agencies to assess and improve their levee risk assessment methodology. Accurate computation of the flood flow magnitude and timing associated with a levee breach remains one of the most difficult and uncertain components of levee risk analysis. Contemporary methods are largely empirical and approximate, introducing substantial uncertainty to the damage and life loss models. Levee breach progressions are often extrapolated to the final width and breach formation time based on limited experience with past breaches or using regression equations developed from a limited data base of dam failures. Physically based embankment erosion models could improve levee breach modeling. However, while several mechanistic embankment breach models are available, they were developed for dams. Several aspects of the levee breach problem are distinct, departing from dam breach assumptions. This study applies three embankments models developed for dam breach analysis (DL Breach, HR BREACH, and WinDAM C to historic levee breaches with observed (or inferred breach rates, assessing the limitations, and applicability of each model to the levee breach problem.

  14. A Method for Probabilistic Stability Analysis of Earth Dams

    Directory of Open Access Journals (Sweden)

    T. R. Mafioleti

    2016-01-01

    Full Text Available This paper proposes a new probabilistic methodology for analyzing the stability of Earth Dams, based on the technique of the First Order Reliability Method for Structural Reliability. Differently from others methodologies present in literature, the proposed method interprets the involved variables as random ones. So, three results are provided here: the Structural Reliability Index, the Probability of Rupture and the most probable values of the random variables for the occurrence of a dam break. In order to illustrate it, real data from a cross section of the Left Bank Earthfill Dam of Itaipu Hydroelectric Power Plant (IHPP, located on the city of Foz do Iguaçu, Paraná, Brazil were used. The numerical results achieved by the proposed methodology evidence that IHPP dam has currently good structural conditions, confirming that the safety procedures adopted in Itaipu Dam may be considered as appropriate. The use of the proposed method enables to complement the previously existing knowledge about the structural conditions, improving the process of risk management.

  15. Dynamic probability evaluation of safety levels of earth-rockfill dams using Bayesian approach

    Institute of Scientific and Technical Information of China (English)

    Zi-wu FAN; Shu-hai JIANG; Ming ZHANG

    2009-01-01

    In order to accurately predict and control the aging process of dams, new information should be collected continuously to renew the quantitative evaluation of dam safety levels. Owing to the complex structural characteristics of dams, it is quite difficult to predict the time-varying factors affecting their safety levels. It is not feasible to employ dynamic reliability indices to evaluate the actual safety levels of dams. Based on the relevant regulations for dam safety classification in China, a dynamic probability description of dam safety levels was developed. Using the Bayesian approach and effective information mining, as well as real-time information, this study achieved more rational evaluation and prediction of dam safety levels. With the Bayesian expression of discrete stochastic variables, the a priori probabilities of the dam safety levels determined by experts were combined with the likelihood probability of the real-time check information, and the probability information for the evaluation of dam safety levels was renewed. The probability index was then applied to dam rehabilitation decision-making. This method helps reduce the difficulty and uncertainty of the evaluation of dam safety levels and complies with the current safe decision-making regulations for dams in China. It also enhances the application of current risk analysis methods for dam safety levels.

  16. Flood hydrology and dam-breach hydraulic analyses of five reservoirs in Colorado

    Science.gov (United States)

    Stevens, Michael R.; Hoogestraat, Galen K.

    2013-01-01

    The U.S. Department of Agriculture Forest Service has identified hazard concerns for areas downstream from five Colorado dams on Forest Service land. In 2009, the U.S. Geological Survey, in cooperation with the Forest Service, initiated a flood hydrology analysis to estimate the areal extent of potential downstream flood inundation and hazard to downstream life, property, and infrastructure if dam breach occurs. Readily available information was used for dam-breach assessments of five small Colorado reservoirs (Balman Reservoir, Crystal Lake, Manitou Park Lake, McGinnis Lake, and Million Reservoir) that are impounded by an earthen dam, and no new data were collected for hydraulic modeling. For each reservoir, two dam-breach scenarios were modeled: (1) the dam is overtopped but does not fail (break), and (2) the dam is overtopped and dam-break occurs. The dam-breach scenarios were modeled in response to the 100-year recurrence, 500-year recurrence, and the probable maximum precipitation, 24-hour duration rainstorms to predict downstream flooding. For each dam-breach and storm scenario, a flood inundation map was constructed to estimate the extent of flooding in areas of concern downstream from each dam. Simulation results of the dam-break scenarios were used to determine the hazard classification of the dam structure (high, significant, or low), which is primarily based on the potential for loss of life and property damage resulting from the predicted downstream flooding.

  17. Dynamic analysis of intake tower in Darab Dam located on limestone

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, H. [Islamic Azad Univ., Tehran (Iran, Islamic Republic of); Hosseini, Y.; Jalaly, H. [Ab-Niru Consulting Engineers, Tehran (Iran, Islamic Republic of); Aghajani, K. [Elam Univ., Elam (Iran, Islamic Republic of)

    2006-07-01

    The Darab dam is located on the Roodbal River in Iran. This paper provided details of the dry intake tower which was designed using 3-D dynamic analysis with the response spectrum method. The intake tower has a 7 meter inner diameter and is 57 meters high with a 70 cm concrete lining connected to the inlet structure of the diversion tunnel. Seismic design criteria were obtained using the annual exceedance probability of 1:500 years. The tower was designed to maintain normal operating conditions after an operating basis earthquake (OBE), maximum design earthquake (MDE) and maximum credible earthquake (MCE). Design accelerogram were derived for the dam site for various return periods. The intake tower was analyzed for 3 accelerograms to cover a range of dam responses. Material and strength properties used for the intake tower were presented. The stress-strain relationship was used for concrete with a limiting concrete compressive strain of 0.004 to avoid excessive damage and spalling of cover concrete. The model included the confining effect provided by transverse steel. The hydrodynamic interaction effect of the surrounding and contained water in the analysis were approximated using an equivalent added mass of water. The tower was modelled using a finite element method. The calculated shear and moment were compared with base shear and base moment. The response spectrum analysis showed that the maximum displacement at the top point of the intake tower with hydrodynamic pressure was 55.21, and 25.10 without hydrodynamic pressure. The time history analysis showed a maximum compressive strain limit of 0.004. The ultimate thickness of the concrete was calculated based on the response spectrum analysis result and compared with the time history analysis. It was concluded that the appropriate thickness of the concrete was determined as 70 cm for the entire height of the tower. 9 refs., 1 tab., 7 figs.

  18. Hydrogeophysics and Water Balance of Cerro Prieto Dam, NE Mexico

    Science.gov (United States)

    Yutsis, V.; de León Gómez, H.; Masuch Oesterreich, D.; Izaguirre, F.

    2007-05-01

    The geographical location of the State of Nuevo Leon, due to its physiographic features, has temperate and arid climate; undeveloped drainage, low precipitations, and high evapotranspiration rates, as well as rapid demographic growth. The hydrological data of the Pablillo basin, registered in the hydrometric station Cerro Prieto, showed an annual precipitation from 415 up to 1130 mm/a , the mean evaporation of 705 mm/a (up to 2460 mm/a in 1996). The maximum water storage of the Cerro Prieto reservoir is 395 millions m3 which corresponds to a water level of 295 meters. However, this level was reached only three times after the dam's construction. By the end of June 2006 the water level was at 276.2 m which corresponds to a water volume of about 127,806,300 m3 which is less than a third of maximum storage. Analysis of hydrological data showed sufficient misbalance between water recharge (by rain, river flow) and loss due to evaporation, filtration, extraction, discharge, etc. 160 gravity reading points, 400 onshore magnetic field readings as well as about 250 offshore magnetic points were carried out. The standard corrections as instrumental drift, latitude, elevation, IGRF, etc. were applied to obtained data. Data procession includes Fourier transformation, wavelength filters, upward continuation, vertical and horizontal derivates, etc. As a result a 2D geological-geophysical models and 3D maps were elaborated. The general trend of the magnetic field reduced to a pole is NW - SE on which background anomalies of northeast trend are obviously traced. The general trend of the gravity field received as a result of our works is the same. However, local magnetic and residual gravity anomalies have mosaic character and, being morphologically extended in a NE direction, grouped in chains of northwest trend. Potential data interpretation allows assuming a series of the superficial fractures focused in a NE direction, perpendicular (NW-SE) to the general deep fault. The

  19. Vortices in dam reservoir: A case study of Karun III dam

    Indian Academy of Sciences (India)

    Maryam Azarpira; Hamed Sarkardeh; Sasan Tavakkol; Reza Roshan; Hossein Bakhshi

    2014-10-01

    The present study focuses on the effect of vortex formation on plane velocities in a reservoir. Velocity measurements are performed in the hydraulic model of Karun III dam and hydropower plant. Different vortices were produced at the horizontal intake by changing the submerged depth. Tangential velocities were measured on a rectangular mesh in the reservoir. The results were then processed to plot the contour lines of the plane velocities and study the effect of vortex formation on the flow condition in the reservoir. Contour lines in different submerged depths show that circulation zones are formed in different potential locations over the intakes causing vortex formation. These results were correlated with the location of the appearing vortices observed in the experiments. Experimental data of this study could be useful for numerical modelling of vortex in the reservoirs.

  20. Sediment trapping by dams creates methane emission hot spots

    DEFF Research Database (Denmark)

    Maeck, A.; Delsontro, T.; McGinnis, Daniel F.

    2013-01-01

    Inland waters transport and transform substantial amounts of carbon and account for similar to 18% of global methane emissions. Large reservoirs with higher areal methane release rates than natural waters contribute significantly to freshwater emissions. However, there are millions of small dams...... worldwide that receive and trap high loads of organic carbon and can therefore potentially emit significant amounts of methane to the atmosphere. We evaluated the effect of damming on methane emissions in a central European impounded river. Direct comparison of riverine and reservoir reaches, where...... sedimentation in the latter is increased due to trapping by dams, revealed that the reservoir reaches are the major source of methane emissions (similar to 0.23 mmol CH4 m(-2) d(-1) vs similar to 19.7 mmol CH4 m(-2) d(-1), respectively) and that areal emission rates far exceed previous estimates for temperate...

  1. Social Discounting of Large Dams with Climate Change Uncertainty

    Directory of Open Access Journals (Sweden)

    Marc Jeuland

    2010-06-01

    This paper reviews the recent discounting controversy and examines its implications for the appraisal of an illustrative hydropower project in Ethiopia. The analysis uses an integrated hydro-economic model that accounts for how the dam’s transboundary impacts vary with climate change. The real value of the dam is found to be highly sensitive to assumptions about future economic growth. The argument for investment is weakest under conditions of robust global economic growth, particularly if these coincide with unfavourable hydrological or development factors related to the project. If however long-term growth is reduced, the value of the dam tends to increase. There may also be distributional or local arguments favouring investment, if growth in the investment region lags behind that of the rest of the globe. In such circumstances, a large dam can be seen as a form of insurance that protects future vulnerable generations against the possibility of macroeconomic instability or climate shocks.

  2. Roles for Dam methylation in bacterial chromosome replication

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Koch, Birgit; Skovgaard, Ole;

    GATC sequences in the DNA of Escherichia coli and related species are methylated at the adenine residue by DNA adenine methyltransferase (DamMT). These methylated residues and/or the level of DamMT influence initiation of chromosome replication from the replication origin, oriC, which contain...... an over-representation of GATC sites, in at least two ways. First, full methylation of oriC promotes duplex opening and hence certain oriC mutants are dependent on Dam methylation for initiation. Second, newly replicated and hemimethylated origins, are bound by SeqA (‘sequestered’) and remain inactive...... for initiation is not affected by additional SeqA whereas DnaA binding to sites outside the origin is inhibited by increased sequestration and/or hemimethylation....

  3. Environmental Risk Assessment System for Phosphogypsum Tailing Dams

    Directory of Open Access Journals (Sweden)

    Xin Sun

    2013-01-01

    Full Text Available This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

  4. Environmental risk assessment system for phosphogypsum tailing dams.

    Science.gov (United States)

    Sun, Xin; Ning, Ping; Tang, Xiaolong; Yi, Honghong; Li, Kai; Zhou, Lianbi; Xu, Xianmang

    2013-01-01

    This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

  5. Detection of subcritical crack propagation for concrete dams

    Institute of Scientific and Technical Information of China (English)

    BAO TengFei; YU Hong

    2009-01-01

    Subcritical propagation of cracks is a warning sign of fracture.If such propagation is detected at an early stage,timely maintenance measures can be taken to prevent the failure of structures.To detect the subcritical propagation of a crack,the crack needs to be monitored continuously in a long term,which is not realistic under certain conditions.However,cracks in concrete dams can be monitored continuously by dam monitoring to offer possible detection for subcritical propagation.In this paper,with measured crack openings from dam monitoring,a state equation for characterizing crack development is established based on the grey system theory.The relation between the stability of the equation and the subcritical crack propagation is investigated,then a criterion is proposed for detecting subcritical propagation.An example demonstrates the validity of the criterion and its potential for practical application.

  6. Introduction of an Emergency Response Plan for flood loading of Sultan Abu Bakar Dam in Malaysia

    Science.gov (United States)

    Said, N. F. Md; Sidek, L. M.; Basri, H.; Muda, R. S.; Razad, A. Z. Abdul

    2016-03-01

    Sultan Abu Bakar Dam Emergency Response Plan (ERP) is designed to assist employees for identifying, monitoring, responding and mitigation dam safety emergencies. This paper is outlined to identification of an organization chart, responsibility for emergency management team and triggering level in Sultan Abu Bakar Dam ERP. ERP is a plan that guides responsibilities for proper operation of Sultan Abu Bakar Dam in respond to emergency incidents affecting the dam. Based on this study four major responsibilities are needed for Abu Bakar Dam owing to protect any probable risk for downstream which they can be Incident Commander, Deputy Incident Commander, On-Scene Commander, Civil Engineer. In conclusion, having organization charts based on ERP studies can be helpful for decreasing the probable risks in any projects such as Abu Bakar Dam and it is a way to identify and suspected and actual dam safety emergencies.

  7. Crucial technologies in High the design of Xiluodu Super Arch Dam

    Institute of Scientific and Technical Information of China (English)

    Wang Renkun

    2012-01-01

    Some super high arch dams ( SHADs), like Xiluodu Arch Dam, after their heights reaching the magnitude of 300 m, confront lots of technical challenges in design and construction. Several crucial technologies of 6 SHADs will be reviewed and discussed in this and consecutive papers, including Xiluodu, Jinping I in China, Baktiary in Iran, ete. , on the topics of the research method, criterion for evaluation and engineering application of dam safety analysis and evaluation, reasonable dam base interface, dam shape optimization, comprehensive treatments of complex foundation, anti-seismic engineering, dam construction material, concrete placement and temperature control, instrumentation and monitoring of dam operation, etc. This paper will mainly focus on the overall safety of SHADs, reasonable dam base interface analysis and evaluation and their engineering application.

  8. Wear and Thermal Stress Analysis of Side Dam for Twin Roll Strip Casting

    Institute of Scientific and Technical Information of China (English)

    LI Chao-feng; DI Hong-shuang; ZHANG Xiao-ming; WANG Guo-dong; LIU Xiang-hua

    2004-01-01

    The side dam technology for twin roll strip casting was discussed. The effect of pre-heating temperature, material and design of side dam on the process stability and surface quality of products was analyzed. The wear and erosion of side dam for different steel grades were described. Two types of side dam designs, namely integral type and combined type, were used in the experiment, and the suitable position of side dam was determined by experiment. The results show that the combined side dam is better than the integral one in process stability and long service life. The temperature fields and thermal stress fields in side dam during strip casting were analyzed using the finite element analysis software, and the causes of side dam cracking were explained.

  9. Prediction of downstream geomorphological changes after dam construction: A stream power approach

    DEFF Research Database (Denmark)

    Brandt, Anders

    2000-01-01

    physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry......physical geography, hydrology, reservoirs, sediment transport, erosion, sedimentation, fluvial geomorphology, dams, river channel geometry...

  10. EnviroAtlas - National Inventory of Dams for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of the National Dams Inventory data from 2009 survey. The file contains counts of inventoried dams by 12-digit hydrologic...

  11. Thermal margin comparison between DAM and simple model

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jeonghun; Yook, Daesik [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2017-01-15

    The nuclear industry in Korea, has considered using a detail analysis model (DAM), which described each rod, to get more thermal margin with the design a dry storage facility for nuclear spent fuel (NSF). A DAM is proposed and a thermal analysis to determine the cladding integrity is performed using test conditions with a homogenized NSF assembly analysis model(Simple model). The result show that according to USA safety criteria, temperature of canister surface has to keep below 500 K in normal condition and 630 K in excess condition. A commercial Computational Fluid Dynamics (CFD) called ANSYS Fluent version 14.5 was used.

  12. Merowe Dam and the inundation of paleochannels of the Nile

    CERN Document Server

    Sparavigna, Amelia Carolina

    2010-01-01

    The course of the Nile in northern Sudan follows a contorted path through bedrocks, creating the Great Bend. Few years ago, the satellite images showed a fertile strip of land with villages, where paleochannels of the river hosted many fields with cultivations and archaeological sites. Now, a huge part of this valley is under the waters of Merowe Dam reservoir. Comparing the images of the region before and after the dam gates were closed, we can see that the reservoir created itself through flooding the paleochannels.

  13. Rollers in low-head dams - Challenges and solutions

    Science.gov (United States)

    Zamankhan, Piroz

    2012-12-01

    Low-head dams exist in many rivers for the purposes of diverting water for open-channel irrigation and providing power plants with cooling water. Flow over low-head dams is quite complex and dangerous rollers often develop down-stream that tend to trap and submerge floating objects. This paper presents an analysis of the problem based on physical and computational fluid dynamics (CFD) modeling and the result of this analysis in the form of design suggestions intended to diminish the hazards associated with rollers.

  14. Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River

    Science.gov (United States)

    Skalak, Katherine; Benthem, Adam J.; Schenk, Edward R.; Hupp, Cliff R.; Galloway, Joel M.; Nustad, Rochelle A.; Wiche, Gregg J.

    2013-01-01

    The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries, and habitat. Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Though the effects of dams and reservoirs are well-documented, their impacts have been studied individually, with relatively little attention paid to their interaction along a river corridor. We examine the morphological and sedimentological changes in the Upper Missouri River between the Garrison Dam in ND (operational in 1953) and Oahe Dam in SD (operational in 1959). Through historical aerial photography, stream gage data, and cross sectional surveys, we demonstrate that the influence of the upstream dam is still a major control of river dynamics when the backwater effects of the downstream reservoir begin. In the “Anthropocene”, dams are ubiquitous on large rivers and often occur in series, similar to the Garrison Dam Segment. We propose a conceptual model of how interacting dams might affect river geomorphology, resulting in distinct and recognizable morphologic sequences that we term “Inter-Dam sequence” characteristic of major rivers in the US.

  15. Compliance Monitoring of Subyearling Chinook Salmon Smolt Survival and Passage at Bonneville Dam, Summer 2012

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam; Ploskey, Gene R.; Weiland, Mark A.; Hughes, James S.; Woodley, Christa M.; Deng, Zhiqun; Carlson, Thomas J.

    2013-05-01

    The purpose of this compliance study was to estimate dam passage survival of subyearling Chinook salmon at Bonneville Dam during summer 2012, as required by the 2008 Federal Columbia River Power System Biological Opinion. The study also estimated smolt passage survival from the forebay 2 km upstream of the dam to the tailrace 1 km below the dam, as well as forebay residence time, tailrace egress, and spill passage efficiency, as required in the 2008 Columbia Basin Fish Accords.

  16. Seismic Fortification Analysis of the Guoduo Gravity Dam in Tibet, China

    OpenAIRE

    Peng Lin; Wenwei Zheng; Bo Huang; Haichao Zhang

    2015-01-01

    The primary aim of this research was to analyze the seismic performance of the Guoduo gravity dam. A nonlinear FEM method was implemented to study the deformation, stress, and overall stability of dam under both static and dynamic loading conditions, including both normal and overloading conditions. A dam seismic failure risk control method is proposed based on the cracking mechanism induced by the dynamic load to ensure dam safety and stability. Numerical simulation revealed that (1) under n...

  17. Past, Present, and Future Nutrient Quality of a Small Southeastern River: A Pre-Dam Assessment

    OpenAIRE

    Stewart, Paul M.; Miller, Jonathan M

    2013-01-01

    Riverine dams alter both the physical environment and water chemistry, thus affecting species assemblages within these environments. In the United States, dam construction is on the decline and there is a growing trend for dam removal. The Choctawhatchee, Pea, and Yellow Rivers Watershed Management Authority had initiated the permitting process for placing a reservoir dam on the Little Choctawhatchee River (LCR), a tributary to the Choctawhatchee River. The purpose of the proposed reservoir w...

  18. 凝视风景——眺望前方与关注当下%Viewing Landscapes—The Look-out's and the Look-at's

    Institute of Scientific and Technical Information of China (English)

    莱蒙德·罗德沃尔德; 李文; 杨滨章

    2012-01-01

    In this paper, the author presents, with Switzerland as an example, the features and trends for the development of landscape architecture in Western countries from four aspects. Firstly, the author describes the current dilemma for landscape architecture faced by the urban development and the improvement for people's lives, which the quality of landscape was increasingly degenerated by urban sprawl and the natural landscape were destroyed by building viewing platforms. Secondly, he reviewed the human exploration of the beautiful landscape, and pointed out the four classic modes, such as the arcadic-pastoral, the sublime, the picturesque and the romantique. Thirdly, he explores the reasons for the degradation of natural scenic quality caused by human activity and the solutions for solving it. Finally, the paper presents that landscape architects should not only look out the future, but also to pay attention to the immediate landscape construction.%从4个方面探讨了以瑞士为代表的西方风景园林发展的特点与趋势.首先阐述了当下风景园林在城市发展和人们生活改善中所面对的窘境,即城市扩张带来的城市景观品质的日益降低和滥建观景平台对自然景观的破坏.其次回顾了人类对优美风景的探索,总结出其中的4种经典风景模式,即田园牧歌式、崇高壮美式、风景如画式和浪漫风情式.再次,探讨了由于人类活动而引发的自然风景品质退化的原因与解决之道.最后提出风景园林师既要关注未来,更要关注当下的风景建设的问题.

  19. Erosion monitoring along the Coosa River below Logan Martin Dam near Vincent, Alabama, using terrestrial light detection and ranging (T-LiDAR) technology

    Science.gov (United States)

    Kimbrow, Dustin R.; Lee, Kathryn G.

    2013-01-01

    Alabama Power operates a series of dams on the Coosa River in east central Alabama. These dams form six reservoirs that provide power generation, flood control, recreation, economic opportunity, and fish and wildlife habitats to the region. The Logan Martin Reservoir is located approximately 45 kilometers east of Birmingham and borders Saint Clair and Talladega Counties. Discharges below the reservoir are controlled by power generation at Logan Martin Dam, and there has been an ongoing concern about the stability of the streambanks downstream of the dam. The U.S. Geological Survey, in cooperation with Alabama Power conducted a scientific investigation of the geomorphic conditions of a 115-meter length of streambank along the Coosa River by using tripod-mounted terrestrial light detection and ranging technology. Two surveys were conducted before and after the winter flood season of 2010 to determine the extent and magnitude of geomorphic change. A comparison of the terrestrial light detection and ranging datasets indicated that approximately 40 cubic meters of material had been eroded from the upstream section of the study area. The terrestrial light detection and ranging data included in this report consist of electronic point cloud files containing several million georeferenced data points, as well as a surface model measuring changes between scans.

  20. Identification and prioritization of subwatersheds for land and water management in Tekeze dam watershed, Northern Ethiopia

    Directory of Open Access Journals (Sweden)

    Kidane Welde

    2016-03-01

    Full Text Available Sedimentation and/or soil erosion are huge problems that have threatened many reservoirs in the Northern Ethiopian highlands, particularly in the Tekeze dam watershed. This study has been conducted to identify and prioritize the most sensitive subwatersheds with the help of a semi-distributed watershed model (SWAT 2009 for improved management of reservoir sedimentation mitigating strategies at the watershed level. SWAT 2009 was chosen for this study due to its ability to produce routed sediment yield and identify principal sediment source areas at the selected point of interest. Based on a digital elevation model (DEM the catchment was divided in to 47 subwatersheds using the dam axis as the main outlet. By overlaying land use, soil and slope of the study area, the subwatersheds were further divided in to 690 hydrological response units (HRUs. Model calibration (for the period of January 1996 to December 2002 and validation (for the period of January 2003 to December 2006 were carried out for stream flow rate and sediment yield data observed at Emba madre gage station. The results of model performance evaluation statistics for both stream flow and sediment yield shows that the model has a high potential in estimation of stream flow and sediment yield. Tekeze dam watershed has mean annual stream flow of 137.74 m3/s and annual sediment yield of 15.17 t/ha/year. Out of the 47 subwatersheds, 13 subwatersheds (mostly located in the north eastern and north western part of the catchment were prioritized. The maximum sediment outflow of these 13 subwatersheds, ranges from 18.49 to 32.57 t/ha/year and are characterized dominantly by cultivated land, shrub land & bare land with average land slope ranging from 7.9 to15.2% and with the dominant soil type of Eutric cambisols. These results can help to formulate and implement effective, appropriate and sustainable watershed management which in turn can help in sustaining the reservoir storage capacity of

  1. Block-to-Point Fine Registration in Terrestrial Laser Scanning

    Directory of Open Access Journals (Sweden)

    Jin Wang

    2013-12-01

    Full Text Available Fine registration of point clouds plays an important role in data analysis in Terrestrial Laser Scanning (TLS. This work proposes a block-to-point fine registration approach to correct the errors of point clouds from TLS and of geodetic networks observed using total stations. Based on a reference coordinate system, the block-to-point estimation is performed to obtain representative points. Then, fine registration with a six-parameter transformation is performed with the help of an Iterative Closest Point (ICP method. For comparisons, fine registration with a seven-parameter transformation is introduced by applying a Singular Value Decomposition (SVD algorithm. The proposed method not only corrects the registration errors between a geodetic network and the scans, but also considers the errors among the scans. The proposed method was tested on real TLS data of a dam surface, and the results showed that distance discrepancies of estimated representative points between scans were reduced by approximately 60%.

  2. A continous Bayesian network for earth dams' risk assessment: methodology and quantification

    NARCIS (Netherlands)

    Morales-Napoles, O.; Delgado-Hernadez-D.J.; De-Leon-Escobedo, D.; Arteaga-Arcos, J.C.

    2013-01-01

    Dams’ safety is highly important for authorities around the world. The impacts of a dam failure can be enormous. Models for investigating dam safety are required for helping decision-makers to mitigate the possible adverse consequences of flooding. A model for earth dam safety must specify clearly p

  3. The Cemented Material Dam: A New, Environmentally Friendly Type of Dam

    National Research Council Canada - National Science Library

    Jinsheng Jia Michel Lino Feng Jin Cuiying Zheng

    2016-01-01

    The first author proposed the concept of the cemented material dam (CMD) in 2009. This concept was aimed at building an environmentally friendly dam in a safer and more economical way for both the dam and the area downstream...

  4. Characteristics of stress distribution in trapezoid-shaped CSG dam during earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, M.; Kawasaki, H. [Ministry of Land, Infrastructure and Transport (Japan). Water Management and Dam Division; Sasaki, T. [Public Works Research Institute, Tsukuba (Japan). Hydraulic Engineering Research Group

    2004-07-01

    There is currently a shortage of dam sites with optimal conditions in Japan. Dam design and construction technologies must also respond to a growing demand for cost reductions and environmental concerns. Cemented Sand and Gravel (CSG) is a new dam construction material that reduces the costs of material production. However, it is not as strong as concrete. The trapezoid shape was proposed to resolve this problem, as a trapezoidal cross section can minimize stress inside the dam body and reduce fluctuations during earthquakes. This paper examines the effects of dam size and the deformability of the foundation ground on the dynamic behavior of a trapezoid-shaped CSG dam during an earthquake, as well as examining the differences between the dynamic behaviors of trapezoid-shaped CSG dams and conventional concrete gravity dams. Finite element models of both dams were used to conduct the comparison. Analysis results included stress distribution during usual loading conditions. It was concluded that stress generated inside the dam body of trapezoid-shaped CSG during earthquakes is considerably lower than concrete gravity dams with a conventional triangle shape. In addition, stress distribution inside the dam body is affected largely by the relative deformability of the foundation to CSG. 4 refs., 2 tabs.,12 figs.

  5. Landscape context and the biophysical response of rivers to dam removal in the United States

    Science.gov (United States)

    Foley, Melissa M.; Magilligan, Francis J.; Torgersen, Christian; Major, Jon J.; Anderson, Chauncey; Connolly, Patrick J.; Wieferich, Daniel; Shafroth, Patrick B.; Evans, James E.; Infante, Dana M.; Craig, Laura

    2017-01-01

    Dams have been a fundamental part of the U.S. national agenda over the past two hundred years. Recently, however, dam removal has emerged as a strategy for addressing aging, obsolete infrastructure and more than 1,100 dams have been removed since the 1970s. However, only 130 of these removals had any ecological or geomorphic assessments, and fewer than half of those included before- and after-removal (BAR) studies. In addition, this growing, but limited collection of dam-removal studies is limited to distinct landscape settings. We conducted a meta-analysis to compare the landscape context of existing and removed dams and assessed the biophysical responses to dam removal for 63 BAR studies. The highest concentration of removed dams was in the Northeast and Upper Midwest, and most have been removed from 3rd and 4th order streams, in low-elevation (landscape settings, which limits predictive capacity in other environmental settings. Biophysical responses to dam removal varied by landscape cluster, indicating that landscape features are likely to affect biophysical responses to dam removal. However, biophysical data were not equally distributed across variables or clusters, making it difficult to determine which landscape features have the strongest effect on dam-removal response. To address the inconsistencies across dam-removal studies, we provide suggestions for prioritizing and standardizing data collection associated with dam removal activities.

  6. 77 FR 2970 - Gibson Dam Hydroelectric Company, LLC, Montana; Notice of Availability of Final Environmental...

    Science.gov (United States)

    2012-01-20

    ... Energy Regulatory Commission Gibson Dam Hydroelectric Company, LLC, Montana; Notice of Availability of... 47897), the Office of Energy Projects has reviewed the application for license for the Gibson Dam Hydroelectric Project, located at the U.S. Department of the Interior, Bureau of Reclamation's Gibson dam on...

  7. 75 FR 81464 - Safety Zone; Columbia River, The Dalles Lock and Dam

    Science.gov (United States)

    2010-12-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Columbia River, The Dalles Lock and Dam... temporary safety zone on the waters of the Columbia River in the vicinity of The Dalles Lock and Dam while... Dalles Lock and Dam (a) Location. The following is a safety zone: All waters of the Columbia...

  8. 76 FR 20707 - Cle Elum Dam Fish Passage Facilities and Fish Reintroduction Project; Kittitas County, WA

    Science.gov (United States)

    2011-04-13

    ... Bureau of Reclamation Cle Elum Dam Fish Passage Facilities and Fish Reintroduction Project; Kittitas... Environmental Impact Statement (FEIS) for the Cle Elum Dam Fish Passage Facilities and Fish Reintroduction... FEIS on the proposed Cle Elum Dam Fish Passage Facilities and Fish Reintroduction Project....

  9. 75 FR 30805 - Gibson Dam Hydroelectric Company, LLC; Notice Soliciting Comments, and Final Terms and Conditions...

    Science.gov (United States)

    2010-06-02

    ... Energy Regulatory Commission Gibson Dam Hydroelectric Company, LLC; Notice Soliciting Comments, and Final... Commission and is available for public inspection. a. Type of Application: Major Project--Existing Dam. b. Project No.: P-12478-003. c. Date filed: August 28, 2009. d. Applicant: Gibson Dam Hydroelectric...

  10. 78 FR 35630 - Martin Dam Hydroelectric Project; Notice of Availability of the Draft Environmental Impact...

    Science.gov (United States)

    2013-06-13

    ... Energy Regulatory Commission Martin Dam Hydroelectric Project; Notice of Availability of the Draft Environmental Impact Statement for the Martin Dam Hydroelectric Project and Intention To Hold Public Meetings In... reviewed the application for license for the Martin Dam Hydroelectric Project (FERC No. 349), located...

  11. 76 FR 26718 - Gibson Dam Hydroelectric Company, LLC; Notice of Availability of Draft Environmental Assessment

    Science.gov (United States)

    2011-05-09

    ... Energy Regulatory Commission Gibson Dam Hydroelectric Company, LLC; Notice of Availability of Draft... Energy Projects has reviewed the application for license for the Gibson Dam Hydroelectric Project, located at the U.S. Department of the Interior, Bureau of Reclamation's, Gibson dam on the Sun River...

  12. 76 FR 54487 - Charter Renewal, Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2011-09-01

    ... Bureau of Reclamation Charter Renewal, Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of... the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group... of the Glen Canyon Dam Adaptive Management Work Group is in the public interest in connection...

  13. 78 FR 54482 - Charter Renewal, Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2013-09-04

    ... Bureau of Reclamation Charter Renewal, Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of... the Glen Canyon Dam Adaptive Management Work Group. The purpose of the Adaptive Management Work Group... Canyon Dam Adaptive Management Work Group is in the public interest in connection with the performance...

  14. A continous Bayesian network for earth dams' risk assessment: methodology and quantification

    NARCIS (Netherlands)

    Morales-Napoles, O.; Delgado-Hernadez-D.J.; De-Leon-Escobedo, D.; Arteaga-Arcos, J.C.

    2013-01-01

    Dams’ safety is highly important for authorities around the world. The impacts of a dam failure can be enormous. Models for investigating dam safety are required for helping decision-makers to mitigate the possible adverse consequences of flooding. A model for earth dam safety must specify clearly p

  15. Fish assemblage response to a small dam removal in the Eightmile River system, Connecticut, USA.

    Science.gov (United States)

    Poulos, Helen M; Miller, Kate E; Kraczkowski, Michelle L; Welchel, Adam W; Heineman, Ross; Chernoff, Barry

    2014-11-01

    We examined the effects of the Zemko Dam removal on the Eightmile River system in Salem, Connecticut, USA. The objective of this research was to quantify spatiotemporal variation in fish community composition in response to small dam removal. We sampled fish abundance over a 6-year period (2005-2010) to quantify changes in fish assemblages prior to dam removal, during drawdown, and for three years following dam removal. Fish population dynamics were examined above the dam, below the dam, and at two reference sites by indicator species analysis, mixed models, non-metric multidimensional scaling, and analysis of similarity. We observed significant shifts in fish relative abundance over time in response to dam removal. Changes in fish species composition were variable, and they occurred within 1 year of drawdown. A complete shift from lentic to lotic fishes failed to occur within 3 years after the dam was removed. However, we did observe increases in fluvial and transition (i.e., pool head, pool tail, or run) specialist fishes both upstream and downstream from the former dam site. Our results demonstrate the importance of dam removal for restoring river connectivity for fish movement. While the long-term effects of dam removal remain uncertain, we conclude that dam removals can have positive benefits on fish assemblages by enhancing river connectivity and fluvial habitat availability.

  16. Examination of physical and regulatory variables leading to small dam removal in Wisconsin.

    Science.gov (United States)

    Orr, Cailin H; Roth, Brian M; Forshay, Kenneth J; Gonzales, James D; Papenfus, Michael M; Wassell, Rebecca D G

    2004-01-01

    The decision to remove or repair a dam depends on multiple variables, many of which encompass both physical and social factors. In Wisconsin, the Department of Natural Resources is mandated to inspect small dams every ten years. A safety inspection often acts as a trigger event to a dam removal or repair decision. Although the issues surrounding a dam removal decision are often couched as ecological, these decisions are influenced by their social and regulatory context. In this work, we examine descriptive variables of Wisconsin dams that were inspected and consequently removed or maintained between 1985 and 1990. We hypothesize that geographic location, height of dam, size of impoundment, age of dam, and type of ownership determine the likelihood of a safety inspection, and the subsequent likelihood of removal. Using a logistic model, we find that publicly owned dams had the greatest probability of inspection after 1985. Of these dams, older dams and those with smaller impoundments were most likely to be removed. We were unable to build a strong predictive model for dam removal with our suite of variables, suggesting that a community's decision to remove or maintain a dam is complex and heterogeneous.

  17. 33 CFR 208.82 - Hetch Hetchy, Cherry Valley, and Don Pedro Dams and Reservoirs.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Hetch Hetchy, Cherry Valley, and..., Cherry Valley, and Don Pedro Dams and Reservoirs. The Turlock Irrigation District and Modesto Irrigation..., shall operate Hetch Hetchy Dam and Reservoir and Cherry Valley Dam and Reservoir in the interest...

  18. Geotechnical sounding of the UTE-Uruguay dams; La auscultacion geotecnica de las presas de UTE

    Energy Technology Data Exchange (ETDEWEB)

    Patrone Matteo, Julio C.; Rosriguez Pastorino, Sandra; Mandia Bica, Magdalena [Administracion Nacional de Usinas e Transmisiones Electricas (UTE), Montevideo (Uruguay)]. E-mail: gsgh@ute.com.uy

    1998-07-01

    This paper addresses specifically to the soil dams, and soil dikes of the Constitucion Dam, which is presently the most instrumented, considering that the set of inspection routine and instrumentation data, including the interpretation and behaviour evaluation, are the basis for the dam sounding.

  19. Parameters inversion of high central core rockfill dams based on a novel genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHOU Wei; LI ShaoLin; MA Gang; CHANG XiaoLin; MA Xing; ZHANG Chao

    2016-01-01

    Parameters identification of rockfill materials is a crucial issue for high rockfill dams.Because of the scale effect,random sampling and sample disturbance,it is difficult to obtain the actual mechanical properties of rockfill from laboratory tests.Parameters inversion based on in situ monitoring data has been proven to be an efficient method for identifying the exact parameters of the rockfill.In this paper,we propose a modified genetic algorithm to solve the high-dimension multimodal and nonlinear optimal parameters inversion problem.A novel crossover operator based on the sum of differences in gene fragments (SoDX) is proposed,inspired by the cloning of superior genes in genetic engineering.The crossover points are selected according to the difference in the gene fragments,defining the adaptive length.The crossover operator increases the speed and accuracy of algorithm convergence by reducing the inbreeding and enhancing the global search capability of the genetic algorithm.This algorithm is compared with two existing crossover operators.The modified genetic algorithm is then used in combination with radial basis function neural networks (RBFNN) to perform the parameters back analysis of a high central earth core rockfill dam.The settlements simulated using the identified parameters show good agreement with the monitoring data,illustrating that the back analysis is reasonable and accurate.The proposed genetic algorithm has considerable superiority for nonlinear multimodal parameter identification problems.

  20. Determination of optimum minimum flow from a dam by using energy analysis

    Science.gov (United States)

    Williams, James B.; McKellar, Henry N.

    1984-07-01

    The proposed restoration of an abandoned hydroelectric dam on the Quinebaug River, Connecticut, is studied using energy analysis. The analysis considers the effects of alternative minimum flow releases, ranging from 0 to 34 cubic meters per second (cms), on the total energy flow of the affected system. The principal system components affected by differing minimum flows are hydroelectric power generation, aquatic habitat, and gross aquatic ecosystem productivity. The minimum flow alternative resulting in the highest annual energy flow in the affected system is considered optimal. From this purely analytical point of view, the optimum minimum flow is 0 cms, due to the short length and low productivity of the regulated reach, and the lack of floodplain interactions. Simulations of longer and more productive river reaches were conducted. For very short, unproductive reaches, in the absence of a floodplain, the contribution of aquatic community productivity to total system energy flow is negligible compared to hydroelectric generation. Optimum minimum flows are higher for longer and more productive reaches. For such cases the operation of hydroelectric dams could reduce total system energy flow because the energy supplied by hydroelectric generation may be offset by losses in aquatic productivity due to diminished riverine habitat.

  1. What are check dams made for? An historical perspective from the French experience

    Science.gov (United States)

    Piton, Guillaume; Carladous, Simon; Recking, Alain

    2015-04-01

    technical and sociological reasons. The Mountain lands' conservation and restoration law of 1882 aimed to better fit local issues. The idea of the presentation is thus to highlight how evolved the historical comprehension of torrential hazards and of the usefulness of check dams in mitigation plans in a changing environment on the technical as well as on the sociological and regulatory points of view. Pioneering scientific and technical works on torrential hydraulics and check dams will be presented. Describing the global context that leads to French laws of 1860,1864 and 1882 will allow us to explain the extensive development of the works in more than a thousand of torrents and a hundred of big landslides. We then will discuss the evolution of technics during the beginning of the 20th century and the changes induced after WWII by the arrival of reinforced-concrete technics. We will conclude the presentation with a synthesis table aiming to highlight the different functions of check dams based on a description of their situations in the watershed, compare to other structures' situations and on shape criteria. This historical perspective will hopefully help people to better understand for which purposes some structures have been built in the past centuries and what lessons can be learnt from this assessment.

  2. Dam-induced and natural channel changes in the Saskatchewan River below the E.B. Campbell Dam, Canada

    Science.gov (United States)

    Smith, Norman D.; Morozova, Galina S.; Pérez-Arlucea, Marta; Gibling, Martin R.

    2016-09-01

    The E.B. Campbell Dam on the Saskatchewan River, east-central Saskatchewan, was constructed in 1962, forming Tobin Lake (2.2 billion m3 capacity), which today impounds most fluvial sediment and disrupts normal outflow patterns. Thirty-five kilometers below the dam, the river diverts into a 500 km2 belt of alluvial sediment initiated by an avulsion 140 years ago, rejoining the parent channel 108 km from the dam. Effects of the dam on channel geomorphology, including the historical channel (reach I) and the more recent avulsion-affected channels, were investigated by pre- and post-dam cross section surveys combined with grain-size and bedload measurements. Twenty-three sites were surveyed at least twice, and 14 were resurveyed annually in 2003-2014 (except 2007) during which significant floods occurred in 2005, 2011, and 2013. All channel cross sections up to 81 km below the dam have coarsened and enlarged since closure, resulting in excavation of 35.4 × 106 m3 of channel-perimeter sediment since 1962. The most proximal segment is armored and has changed little in recent years. Since 2003, channel enlargement has been greatest in the 35-81 km segment between the avulsion site and the Forks (reaches II, III), manifested as widening and deepening. Enlargement rates were greatest during the three floods, and the paucity of bedload has prevented degraded portions of the channel bed from replenishment following flooding. Budget calculations based on bedload measurements and channel cross-section areas suggest that > 30 years would be required to replace the sediment removed between 2003 and 2014, assuming all available bedload remains in the affected reach. Dam effects appear to be absent or uncertain beyond 81 km, a multichanneled region of varied stages of activity (reach IV), recombining and eventually rejoining the parent Saskatchewan River channel at km 108 (reach V). Sediment evacuated from reaches I-III is sufficient to sustain modest aggradation in some distal

  3. Plugs or flood-makers? The unstable landslide dams of eastern Oregon

    Science.gov (United States)

    Safran, E. B.; O'Connor, J. E.; Ely, L. L.; House, P. K.; Grant, G.; Harrity, K.; Croall, K.; Jones, E.

    2015-11-01

    Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4-33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40-70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide data sets

  4. Plugs or flood-makers? the unstable landslide dams of eastern Oregon

    Science.gov (United States)

    Safran, Elizabeth B.; O'connor, James; Ely, Lisa L.; House, Kyle; Grant, Gordon E.; Harrity, Kelsey; Croall, Kelsey; Jones, Emily

    2015-01-01

    Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4–33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40–70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide

  5. Eutrophication levels of some South African impoundments III. Roodeplaat Dam

    CSIR Research Space (South Africa)

    Steyn, DJ

    1976-01-01

    Full Text Available Algal bioassays indicated that the waters of Roodeplaat dam are severely eutrophied since algal growth potentials (AGP) of up to 200 mg/l and batch culture algal growth rate of up to 2,2 d were registered with selemastrm capricornutum as test alga...

  6. Modelling autogenous expansion for magnesia concrete in arch dams

    Institute of Scientific and Technical Information of China (English)

    Feng JIN; Guoxin ZHANG; Xiaoqing LUO; Chuhan ZHANG

    2008-01-01

    Magnesia Concrete is a kind of expansive con-crete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expan-sion on the stresses of arch dams, a simple model of auto-genous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expan-sion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogen-ous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite ele-ment arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.

  7. Liquefaction evaluation of dam foundation soils considering overlying structure

    Institute of Scientific and Technical Information of China (English)

    Gang Wang a; Xing Wei b; Hanlong Liu a

    2015-01-01

    The liquefaction analysis procedure conducted at a dam foundation associated with a layer of liquefiable sand is presented. In this case, the effects of the overlying dam and an embedded diaphragm wall on liquefaction potential of foundation soils are considered. The analysis follows the stress-based approach which compares the earthquake-induced cyclic stresses with the cyclic resistance of the soil, and the cyclic resistance of the sand under complex stress condition is the key issue. Comprehensive laboratory monotonic and cyclic triaxial tests are conducted to evaluate the static characteristics, dynamic char-acteristics and the cyclic resistance against liquefaction of the foundation soils. The distribution of the factor of safety considering liquefaction is given. It is found that the zones beneath the dam edges and near the upstream of the diaphragm wall are more susceptible to liquefaction than in free field, whereas the zone beneath the center of the dam is less susceptible to liquefaction than in free field. According to the results, the strategies of ground improvement are proposed to mitigate the liquefaction hazards.

  8. Colorado River Basin Hover Dam - Review of Flood Control Regulation.

    Science.gov (United States)

    1982-07-01

    Percichthyidae Striped bass 1ile sxiiis Pocilldae Mosquito fish Cainbusia affnus Sailfin mollie Poecilia latipin a Mexican mollie Poecila mexicana Salmonidae...Colorado River Basin Progress Report No. 8, 195 pp. Vitt, L.J. and R.D. Ohmart, 1978. Herpetofauna of the Lower Colorado River: Davis Dam to the

  9. Liquefaction evaluation of dam foundation soils considering overlying structure

    Directory of Open Access Journals (Sweden)

    Gang Wang

    2015-04-01

    Full Text Available The liquefaction analysis procedure conducted at a dam foundation associated with a layer of liquefiable sand is presented. In this case, the effects of the overlying dam and an embedded diaphragm wall on liquefaction potential of foundation soils are considered. The analysis follows the stress-based approach which compares the earthquake-induced cyclic stresses with the cyclic resistance of the soil, and the cyclic resistance of the sand under complex stress condition is the key issue. Comprehensive laboratory monotonic and cyclic triaxial tests are conducted to evaluate the static characteristics, dynamic characteristics and the cyclic resistance against liquefaction of the foundation soils. The distribution of the factor of safety considering liquefaction is given. It is found that the zones beneath the dam edges and near the upstream of the diaphragm wall are more susceptible to liquefaction than in free field, whereas the zone beneath the center of the dam is less susceptible to liquefaction than in free field. According to the results, the strategies of ground improvement are proposed to mitigate the liquefaction hazards.

  10. Sliding response of gravity dams including vertical seismic accelerations

    Institute of Scientific and Technical Information of China (English)

    Constantin Christopoulos; Pierre Léger; André Filiatrault

    2003-01-01

    Seismic safety assessment of gravity dams has become a major concern in many regions of the world while the effects of vertical seismic accelerations on the response of structures remain poorly understood. This paper first investigates the effect of including vertical accelerations in the sliding response analysis of gravity dams subjected to a range of historical ground motion records separated in two groups according to their source-to-site distance. Analyses showed that the incidence of vertical accelerations on the sliding response of gravity dams is significantly higher for near-source records than for farsource records. The pseudo-static 30% load combination rule, commonly used in practice to account for the non-simultaneous occurrence of the peak horizontal and vertical accelerations, yielded good approximations of the minimum safety factors against sliding computed from time-history analyses. A method for empirically estimating the vertical response spectra based on horizontal spectra, accounting for the difference in frequency content and amplitudes between the two components is investigated. Results from analyses using spectrum compatible horizontal and vertical synthetic records also approximated well the sliding response of a gravity dam subjected to series of simultaneous horizontal and vertical historical earthquake records.

  11. Enloe Dam Passage Project, Volume I, 1984 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fanning, M.L.

    1985-07-01

    This report discusses issues related to the provision of fish passage facilities at Enloe Dam and the introduction of anadromous salmonid fish to the upper Similkameen River basin. The species of fish being considered is a summer run of steelhead trout adapted to the upper Columbia basin. (ACR)

  12. Characterisation of gold tailings dams of the Witwatersrand Basin ...

    African Journals Online (AJOL)

    2006-10-04

    Oct 4, 2006 ... gen in the Witwatersrand tailings dams is controlled by secondary porosity (i.e. cracks caused .... different properties and characteristics of tailings material. .... Z o n e. O. Z. T. Z. U. Z 1. U. Z 2. O. Z 1. O. Z 2. T. Z. U. Z. O. Z 1. O.

  13. Chromosomal replication incompatibility in Dam methyltransferase deficient Escherichia coli cells

    DEFF Research Database (Denmark)

    Freiesleben, Ulrik Von

    1996-01-01

    Dam methyltransferase deficient Escherichia coli cells containing minichromosomes were constructed. Free plasmid DNA could not be detected in these cells and the minichromosomes were found to be integrated in multiple copies in the origin of replication (oriC) region of the host chromosome...

  14. The Aswan Dam: A Lesson on Man's Environmental Impact.

    Science.gov (United States)

    Peterson, Burnell

    This curriculum unit was prepared for senior high classroom use to teach geography, history, and environmental issues. The objective of the lesson is to illustrate the historical man/river relationship between Egypt and the Nile River, and the impact of the Aswan dam on the agricultural and economic needs of the country today. The lesson requires…

  15. Optimization of Hydroacoustic Equipment Deployment at Foster Dam, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, James S.; Johnson, Gary E.; Ploskey, Gene R.; Hennen, Matthew J.; Fischer, Eric S.; Zimmerman, Shon A.

    2013-03-01

    The goal of the study was to optimize performance of the fixed-location hydroacoustic systems at Foster Dam (FOS) by determining deployment and data acquisition methods that minimized structural, electrical, and acoustic interference. Optimization of the hydroacoustic systems will establish methodology for sampling by active acoustic methods during this year-long evaluation of juvenile salmonid passage at FOS.

  16. 77 FR 67813 - Sam Rayburn Dam Project Power Rate

    Science.gov (United States)

    2012-11-14

    ..., Assistant Administrator, Southwestern Power Administration, Department of Energy, Williams Center Tower I... Southwestern Power Administration Sam Rayburn Dam Project Power Rate AGENCY: Southwestern Power Administration, DOE. ACTION: Notice of Rate Order Approving an Extension of Power Rate on an Interim Basis....

  17. 77 FR 22801 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2012-04-17

    ... Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group AGENCY: Bureau of Reclamation... Management Work Group (AMWG) makes recommendations to the Secretary of the Interior concerning Glen Canyon... AMP includes a Federal advisory committee, the AMWG, a technical work group, a Grand Canyon...

  18. Effects of the Ben Franklin Dam on the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Harty, H.

    1979-04-01

    A previous assessment of the effects of a Ben Franklin Dam on the Hanford Site made in 1967 was updated so that the potential adverse effects may be better understood in light of existing operations, current environmental and safety standards, and proposed facilities and operations. The major effects would probably arise from flooding of portions of the site by the reservoir associated with the dam and by the raising of the ground water table under the site. A preliminary analysis of the effects of the dam is presented, and a number of studies are recommended in order to fully evaluate and understand these potential impacts. The following seven tasks are identified and discussed: groundwater - hydrology analysis; soil liquefaction analysis; hydrostatic uplift and soil effects on structures; assessment of the potential for landsliding and sloughing; facility decommissioning; hydrothermal analysis; and, meteorological effects. Four other aspects commented upon in this report are: aquatic ecology, terrestrial ecology, socioeconomic effects, and public interaction. Possible effects on ongoing DOE-sponsored R and D are also noted. To the extent possible, cost estimates are developed for corrective actions which must be taken on the Hanford Site to accommodate the dam. Where this was not possible, appropriate courses of action leading to cost estimates are presented.

  19. Simulation and control of sediment transport due to dam removal

    Science.gov (United States)

    This paper presents two case studies of post dam removal sedimentation in the United States. Two different one-dimensional channel evolution simulation models were used: CCHE1D and CONCEPTS, respectively. The first case is the application of CCHE1D to assess a long-term morphological response to the...

  20. Simulation of morphological changes due to dam removal

    Science.gov (United States)

    In this chapter, a brief review of numerical models and their applications for impact assessment of dam removal on sediment transport and morphological changes in alluvial rivers is given. As an example, a one-dimensional river flow and sediment transport model, CCHE1D, is applied to assess morpholo...

  1. Hydroelectric power potential, Woonsocket Falls Dam, Woonsocket, Rhode Island

    Energy Technology Data Exchange (ETDEWEB)

    Daly, J C; Dowdell, R B; Kelly, W E; Koveos, P E; Krikorian, Jr, J S; Lengyel, G; Prince, M J; Seely, S; Tromp, L; Urish, D W

    1979-01-01

    The feasibility of developing a hydroelectric power plant at an existing flood control dam of the city of Woonsocket, RI was examined considering environmental, economic, technical and engineering factors. It was concluded that the City should proceed with plans to develop a hydro plant. (LCL)

  2. Optimization of Hydroacoustic Equipment Deployment at Foster Dam, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, James S.; Johnson, Gary E.; Ploskey, Gene R.; Hennen, Matthew J.; Fischer, Eric S.; Zimmerman, Shon A.

    2013-03-01

    The goal of the study was to optimize performance of the fixed-location hydroacoustic systems at Foster Dam (FOS) by determining deployment and data acquisition methods that minimized structural, electrical, and acoustic interference. Optimization of the hydroacoustic systems will establish methodology for sampling by active acoustic methods during this year-long evaluation of juvenile salmonid passage at FOS.

  3. Aquatic Toxicity of the Decontamination Agent: Multipurpose (DAM) decontamination Solution

    Science.gov (United States)

    1994-05-01

    DECONTAMINATION SOLUTION ELETI M.V. Holey •I• E LF- , C.W. Kurnas J •i W.T. Muse B RESEARCH AND TECHNOLOGY DIRECTORATE May 1994 Approved for public release...FUNDING NUMBERS Aquatic Toxicity of the Decontaminating S.O.-2FK4 Agent: Multipurpose (DAM) Decontamination Solution 6. AUTHOR(S) Haley, M.V.; Kurnas

  4. Environment Changes of Lampao Dam Communities in Northeast Thailand

    Directory of Open Access Journals (Sweden)

    Winyoo Sata

    2008-01-01

    Full Text Available Problem statement: The objective of this research was to study the environment change of Lampao Dam communities in Northeast Thailand, being a case study of the Sa-Adnathom community, Lamklong sub-district, Muang, Kalasin province, adjacent to the Lampao Dam. Approach: A qualitative research, it started with a review of literature and related researches. Field data were collected by way of interviews and both participant and non-participant observations, involving 15 informants including senior-villagers, who had lived in the village some 10-20 years. The research data were descriptively analyzed and presented. Results: As a result its was found that the Lampao Dam communities date back 200 years to the era of Chiangsom Kingdom. Deserted due to deadly epidemics, the area was later on repopulated by migrants from Yang Talad district, Kalasin province. A new community, called Sa-Adnathom, was born. Prior to the inception of the National Plan for Social and Economic Development in 1961, the environment of this community was complete with fertile land and natural resource abundance. People lived in harmony with nature and relied on resources from it for their livelihood, especially from Nong Waeng reservoir, Phan and Yang streams and Khoke Ngoo forest. But with the implementation of the first Plan for Social and Economic Development in 1961-1966 the Thai government started the construction of the Lampao Dam in 1963. Completed in 1968, the Dam took land from the villagers, part of which were simply flooded. This forced the village farmers to change their means of livelihood from relying on forest and rivers to production methods which by necessity involved purchase of machines and usage of chemical fertilizers. In short, a change from farming to fishing in Lampao Dam. Their values also changed from local exchanges of goods to money economy, which only led to household debts, increasing with rising degree of consumerism. Eventually people in the

  5. Rubber dam may increase the survival time of dental restorations.

    Science.gov (United States)

    Keys, William; Carson, Susan J

    2017-03-01

    Data sourcesCochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, LILACS, SciELO, Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online databases. Handsearches in a number of journals.Study selectionRandomised controlled trials, including split-mouth studies assessing the effects of rubber dam isolation for restorative treatments in dental patients.Data extraction and synthesisTwo review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies.ResultsFour studies involving a total of 1,270 patients were included. The studies were at high risk of bias. One trial was excluded from the analysis due to inconsistencies in the presented data. Restorations had a significantly higher survival rate in the rubber dam isolation group compared to the cotton roll isolation group at six months in participants receiving composite restorative treatment of non-carious cervical lesions (risk ratio (RR) 1.19, 95% confidence interval (CI) 1.04 to 1.37, very low-quality evidence). The rubber dam group had a lower risk of failure at two years in children undergoing proximal atraumatic restorative treatment in primary molars (hazard ratio (HR) 0.80, 95% CI 0.66 to 0.97, very low-quality evidence). One trial reported limited data showing that rubber dam usage during fissure sealing might shorten the treatment time. None of the included studies mentioned adverse effects or reported the direct cost of the treatment, or the level of patient acceptance/satisfaction. There was also no evidence evaluating the effects of rubber dam usage on the quality of the restorations.ConclusionsWe found some very low-quality evidence, from single studies, suggesting that rubber dam usage in dental direct

  6. Klamath River Water Quality Data from Link River Dam to Keno Dam, Oregon, 2008

    Science.gov (United States)

    Sullivan, Annett B.; Deas, Michael L.; Asbill, Jessica; Kirshtein, Julie D.; Butler, Kenna D.; Vaughn, Jennifer

    2009-01-01

    This report documents sampling and analytical methods and presents field data from a second year of an ongoing study on the Klamath River from Link River Dam to Keno Dam in south central Oregon; this dataset will form the basis of a hydrodynamic and water quality model. Water quality was sampled weekly at six mainstem and two tributary sites from early April through early November, 2008. Constituents reported herein include field-measured water-column parameters (water temperature, pH, dissolved oxygen concentration, specific conductance); total nitrogen and phosphorus; particulate carbon and nitrogen; total iron; filtered orthophosphate, nitrite, nitrite plus nitrate, ammonia, organic carbon, and iron; specific UV absorbance at 254 nanometers; chlorophyll a; phytoplankton and zooplankton enumeration and species identification; and bacterial abundance and morphological subgroups. Sampling program results indicated: *Most nutrient and carbon concentrations were lowest in spring, increased starting in mid-June, remained elevated in the summer, and decreased in fall. Dissolved nitrite plus nitrate had a different seasonal cycle and was below detection or at low concentration in summer. *Although total nitrogen and total phosphorus concentrations did not show large differences from upstream to downstream, filtered ammonia and orthophosphate concentrations increased in the downstream direction and particulate carbon and particulate nitrogen generally decreased in the downstream direction. *Large bacterial cells made up most of the bacteria biovolume, though cocci were the most numerous bacteria type. Cocci, with diameters of 0.1 to 0.2 micrometers, were smaller than the filter pore sizes used to separate dissolved from particulate matter. *Phytoplankton biovolumes were dominated by diatoms in spring and by the blue-green alga Aphanizomenon flos-aquae after mid-June. Another blue-green, Anabaena flos-aquae, was noted in samples from late May to late June. Phytoplankton

  7. National Dam Safety Program. Lock 4 Embankment Waterford Flight Dam (Inventory Number N.Y. 968). Mohawk River Basin, Saratoga County, New York. Phase I Inspection Report,

    Science.gov (United States)

    1981-09-10

    ENGINEERING DATA 2.1 GEOTECHNICAL DATA a. Geology Lock 4 Embankment Waterford Flight Dam is located in the Hudson Valley section of the Valley and Ridge...River are controlled by the up- stream locks (Nos. 5 and 6) and by the Crescent Dam which forms the im- poundment for the navigation channel above Lock...River above Crescent Dan may contribute flow through the canal system. b. Discharge at Dam Site JNo discharge records are available for this site

  8. National Program for Inspection of Non-Federal Dams. Forest Park Upper Dam (MA 00568), Connecticut River Basin, Springfield, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1979-09-01

    PHASE I INSPECTION REPORT NATIONAL DAM INSPECTION PROGRAM Identification No.: MA 00568 N., _-S Name of Dam: FOREST PARK UPPER DAM Town: CITY OF...COmSTR.Cl ON AN , OP[rATdON -, J _A, SUI T IINFERS-_ BOWERS AND PEOLO’ S’A[l -g" HOLYOKE MASSACHUSLTIS TEL J[¢rtc SOs 3 39gq CD Springfield December 2, 1969

  9. National Dam Safety Program. Von Der Ahe Dam (MO 31077), Mississippi - Kaskaskia - St. Louis Basin, Franklin County, Missouri. Phase I Inspection Report.

    Science.gov (United States)

    1980-06-01

    from Controlling Office) IS. SECURITY CLASS. (of thia rePort) National Darn Safety Program. Von der UNLSSFE(~ Ahe Dam (MO 31V77), Mississippi - ISa ...34;TAT1 MiNT I Apro’,,,, for ;,.blhc yele(so |: ’ --- __ ~ ~~ii[ , - rtu : ’ lrrJl": ’,d PHASE I REPORT NATIONAL DAM SAFETY PROGRAM Name of Dam: Von Der Ahe

  10. Computational Fluid Dynamics Modeling of the John Day Dam Tailrace

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, Cynthia L.; Perkins, William A.; Richmond, Marshall C.; Serkowski, John A.

    2010-07-08

    US Army Corps of Engineers - Portland District required that a two-dimensional (2D) depth-averaged and a three-dimensional (3D) free-surface numerical models to be developed and validated for the John Day tailrace. These models were used to assess potential impact of a select group of structural and operational alternatives to tailrace flows aimed at improving fish survival at John Day Dam. The 2D model was used for the initial assessment of the alternatives in conjunction with a reduced-scale physical model of the John Day Project. A finer resolution 3D model was used to more accurately model the details of flow in the stilling basin and near-project tailrace hydraulics. Three-dimensional model results were used as input to the Pacific Northwest National Laboratory particle tracking software, and particle paths and times to pass a downstream cross section were used to assess the relative differences in travel times resulting from project operations and structural scenarios for multiple total river flows. Streamlines and neutrally-buoyant particles were seeded in all turbine and spill bays with flows. For a Total River of 250 kcfs running with the Fish Passage Plan spill pattern and a spillwall, the mean residence times for all particles were little changed; however the tails of the distribution were truncated for both spillway and powerhouse release points, and, for the powerhouse releases, reduced the residence time for 75% of the particles to pass a downstream cross section from 45.5 minutes to 41.3 minutes. For a total river of 125 kcfs configured with the operations from the Fish Passage Plan for the temporary spillway weirs and for a proposed spillwall, the neutrally-buoyant particle tracking data showed that the river with a spillwall in place had the overall mean residence time increase; however, the residence time for 75% of the powerhouse-released particles to pass a downstream cross section was reduced from 102.4 min to 89 minutes.

  11. Compliance Monitoring of Subyearling Chinook Salmon Survival and Passage at The Dalles Dam, Summer 2012

    Energy Technology Data Exchange (ETDEWEB)

    Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam; Ploskey, Gene R.; Weiland, Mark A.; Hughes, James S.; Woodley, Christa M.; Deng, Zhiqun; Carlson, Thomas J.; Johnson, Gary E.

    2013-05-01

    The purpose of this compliance study was to estimate dam passage survival of subyearling Chinook salmon at The Dalles Dam during summer 2012. Under the 2008 Federal Columbia River Power System Biological Opinion, dam passage survival is required to be greater than or equal to 0.93 and estimated with a standard error (SE) less than or equal to 0.015. The study also estimated survival from the forebay 2 km upstream of the dam and through the tailrace to 2 km downstream of the dam, forebay residence time, tailrace egress time, spill passage efficiency (SPE), and fish passage efficiency (FPE), as required by the 2008 Columbia Basin Fish Accords.

  12. Proceedings of the Canadian Dam Association conference 2010: partnering for a safer future

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    New and numerous challenges faced by the the dam safety community and dams were discussed at this conference. Hydraulic resources availability, the durability of the installations, modes of operation and processes, the business environment and human resources in the dam safety community are factors which will influence and impact these challenges. New types of dams have been constructed or are being built. Research is needed and knowledge sharing needs to be promoted to ensure the development of safe and reliable projects. This conference brought together samll dam owners and larger utilities looking for the latest in technology developments.

  13. A review of proposed Glen Canyon Dam interim operating criteria

    Energy Technology Data Exchange (ETDEWEB)

    LaGory, K.; Hlohowskyj, I.; Tomasko, D.; Hayse, J.; Durham, L.

    1992-04-01

    Three sets of interim operating criteria for Glen Canyon Dam on the Colorado River have been proposed for the period of November 1991, to the completion of the record of decision for the Glen Canyon Dam environmental impact statement (about 1993). These criteria set specific limits on dam releases, including maximum and minimum flows, up-ramp and down-ramp rates, and maximum daily fluctuation. Under the proposed interim criteria, all of these parameters would be reduced relative to historical operating criteria to protect downstream natural resources, including sediment deposits, threatened and endangered fishes, trout, the aquatic food base, and riparian plant communities. The scientific bases of the three sets of proposed operating criteria are evaluated in the present report:(1) criteria proposed by the Research/Scientific Group, associated with the Glen Canyon Environmental Studies (GCES); (2) criteria proposed state and federal officials charged with managing downstream resources; and (3) test criteria imposed from July 1991, to November 1991. Data from Phase 1 of the GCES and other sources established that the targeted natural resources are affected by dam operations, but the specific interim criteria chosen were not supported by any existing studies. It is unlikely that irreversible changes to any of the resources would occur over the interim period if historical operating criteria remained in place. It is likely that adoption of any of the sets of proposed interim operating criteria would reduce the levels of sediment transport and erosion below Glen Canyon Dam; however, these interim criteria could result in some adverse effects, including the accumulation of debris at tributary mouths, a shift of new high-water-zone vegetation into more flood-prone areas, and further declines in vegetation in the old high water zone.

  14. Reliability and Robustness Analysis of the Masinga Dam under Uncertainty

    Directory of Open Access Journals (Sweden)

    Hayden Postle-Floyd

    2017-02-01

    Full Text Available Kenya’s water abstraction must meet the projected growth in municipal and irrigation demand by the end of 2030 in order to achieve the country’s industrial and economic development plan. The Masinga dam, on the Tana River, is the key to meeting this goal to satisfy the growing demands whilst also continuing to provide hydroelectric power generation. This study quantitatively assesses the reliability and robustness of the Masinga dam system under uncertain future supply and demand using probabilistic climate and population projections, and examines how long-term planning may improve the longevity of the dam. River flow and demand projections are used alongside each other as inputs to the dam system simulation model linked to an optimisation engine to maximise water availability. Water availability after demand satisfaction is assessed for future years, and the projected reliability of the system is calculated for selected years. The analysis shows that maximising power generation on a short-term year-by-year basis achieves 80%, 50% and 1% reliability by 2020, 2025 and 2030 onwards, respectively. Longer term optimal planning, however, has increased system reliability to up to 95% in 2020, 80% in 2025, and more than 40% in 2030 onwards. In addition, increasing the capacity of the reservoir by around 25% can significantly improve the robustness of the system for all future time periods. This study provides a platform for analysing the implication of different planning and management of Masinga dam and suggests that careful consideration should be given to account for growing municipal needs and irrigation schemes in both the immediate and the associated Tana River basin.

  15. Influences of local habitat, tributary position, and dam characteristics on fish assemblages within impoundments of low-head dams in the tributaries of the Qingyi River, China.

    Science.gov (United States)

    Li, Xian; Li, Yu-Ru; Chu, Ling; Zhu, Ren; Wang, Li-Zhu; Yan, Yun-Zhi

    2016-03-18

    Low-head dam impoundments modify local habitat and alter fish assemblages; however, to our knowledge, the pattern of how fish assemblages in the impoundments relate to local habitat, tributary position, and dam characteristics is still unclear. We used data collected in 62 impoundments created by low-head dams in headwater streams of the Qingyi River, China, to examine relationships between fish assemblages and local habitat, tributary position, and dam characteristics. We also assessed the relative importance of the three groups of factors in determining fish species richness and composition. Linear regression models showed that fish species richness was related to substrate heterogeneity, confluence link, and dam number upstream. Redundancy analysis showed that fish species compositions were influenced by substrate heterogeneity, confluence link, dam height, dam numbers upstream and downstream. Overall, dam characteristics were more important in affecting fish species richness but less important in determining fish species composition than local habitat (i.e., substrate heterogeneity) and tributary position. Our results suggest that low-head dam may affect fish species richness in impoundments by modifying local habitat and constraining fish movement, and the relative abundances of those fish species may depend more on species habitat presences and stream size than on impoundment size and number.

  16. A comparison of metal levels and antioxidant enzymes in freshwater snails, Lymnaea natalensis, exposed to sediment and water collected from Wright Dam and Lower Mguza Dam, Bulawayo, Zimbabwe.

    Science.gov (United States)

    Siwela, A H; Nyathi, C B; Naik, Y S

    2010-10-01

    We compared the bioaccumulation of lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu), nickel (Ni) and iron (Fe) with antioxidant enzyme activity in tissues of the snails, Lymnaea natalensis, exposed to elements of two differently polluted dams. 45 snails were exposed to sediment and water collected from Wight Dam (reference) whilst another 45 snails were also exposed to sediment and water collected from Lower Mguza Dam (polluted dam). Except for Fe in sediment and Pb in water, metal concentrations were statistically higher in sediment and water collected from Lower Mguza Dam. Lead, Cd and Zn were two times higher in tissues of snails exposed to Lower Mguza Dam elements. On one hand, superoxide dismutase (SOD), diphosphotriphosphodiaphorase (DTD) and catalase (CAT) activities were significantly lower whilst malondialdehyde (MDA) levels were significantly higher in tissues of snails exposed to Lower Mguza Dam sediment and water. On the other hand, selenium-dependent glutathione peroxidase (Se-GPX) activity was significantly elevated in tissues of snails exposed to Lower Mguza Dam sediment and water. Snails exposed to Lower Mguza Dam elements seem to have responded to pollution by increasing CAT and Se-GPX specific activity in an effort to detoxify peroxides produced as a result of metal induced oxidative stress.

  17. Dams. Bulletin of the Technical Service of Electric Power and Big Dams; Barrages. Bulletin du Service Technique de l`Energie Electrique et des Grands Barrages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    Three papers were selected in this issue of the bulletin of the Technical Service of Electric Power and Big Dams. The first one concerns the experience feedback gained from the accident of the Drac river near Grenoble (France) due to a spillover at the Notre-Dame-de-Commiers` dam and which led to the death of 6 children and their teacher. The second one is a report of the conclusions of decennial and annual safety inspections of French dams, while the third one is a report of the Control Services activities for the third quarter of the year 1996 concerning the French dams in operation. (J.S.)

  18. National Dam Safety Program. Lac Marseilles Dam (MO 30282), Mississippi - Kaskaskia - St. Louis Basin, St. Francois County, Missouri. Phase I Inspection Report.

    Science.gov (United States)

    1981-01-01

    DACW4-81--OJTnTA 9. PERFORMING ORGANIZATION NAME AND ADDRESS TAREA WORK UNIT NUMBERS K U.S. Army Engineer District, St. Louis Dam Inventory and...The dam was constructed without a set of plans or "as built" records, but we understand that its construction was observed and directed by a...Drainage Basin and Site Topography 3A. Plan and Crest Profile of Dam 3B. Sections of Dam and Spillway 4. Regional Geologic Map APPENDICES A Figure A-I

  19. 33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

    Science.gov (United States)

    2010-07-01

    ... Coast Guard-National Park Service agreement exists for both the Glen Canyon and Lake Mead National..., Nevada, from the Pioneer Hotel to the Edgewater Hotel. Laughlin Aquamoto Sports Challenge and Expo.... PDT. Where: That portion of the Colorado River near Laughlin, Nevada, from Davis Dam to Harrah's Hotel...

  20. A comparison of different rubber dam systems on a dental simulator.

    Science.gov (United States)

    Kapitan, Martin; Sustova, Zdenka; Ivancakova, Romana; Suchanek, Jakub

    2014-01-01

    The purpose of this study was to test the hypothesis that more recently developed rubber dam systems (OptraDam ® Plus and OptiDam™) are faster and easier to handle, and that the quality of isolation is not decreased. The rubber dam systems were applied in standard conditions on a dental simulator in several model clinical situations. The time of preparation, application and removal were measured and the quality of isolation was evaluated. The median time of rubber dam placement was 51 s (Q1 = 38 s; Q3 = 79 s). The shortest median time of application was with OptiDam™ (42 s), followed by a conventional rubber dam (53 s), and finally the longest was with OptraDam® Plus (58 s). The median volume of fluid remaining in the isolated space after 5 minutes was 9.5 mL (Q1 = 8 mL; Q3 = 10 mL). The largest median volume of remaining water was with OptiDam™ (10 mL), followed by a conventional rubber dam (9.5 mL) and the least with OptraDam® Plus (8.5 mL). The afore-stated hypothesis about the advantages of modern rubber dam isolation systems was accepted for OptiDam™, but rejected for OptraDam® Plus. The results could contribute to decision-making concerning the choice of rubber dam system.