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Sample records for park bryce canyon

  1. Passive control potentials of trees and on-street parked cars in reduction of air pollution exposure in urban street canyons

    International Nuclear Information System (INIS)

    Abhijith, K.V.; Gokhale, Sharad

    2015-01-01

    This study investigates the passive-control-potentials of trees and on-street parked cars on pedestrian exposure to air pollutants in a street canyon using three-dimensional CFD. Since, according to some studies trees deteriorate air quality and cars parked roadside improve it, the combine as well as separate effects of trees and on-street parked cars have been examined. For this, different tree canopy layouts and parking configurations have been developed and pedestrian exposure for each has been analysed. The results showed, for example, tree crown with high porosity and low-stand density in combination with parallel or perpendicular car parking reduced the pedestrian exposure considerably. - Highlights: • Trees and on-street parked cars can manipulate pollutant levels in street canyons. • Low stand density trees with 0° or 90° car parking reduce pedestrian exposure. • Trees with medium crown, high porosity, low stand density reduce pollutant levels. - This study investigated the combination of trees and on-street parked cars to manipulate pollutant levels in urban street canyons to reduce pedestrian exposure

  2. Continuing fire regimes in remote forests of Grand Canyon National Park

    Science.gov (United States)

    Peter Z. Fule; Thomas A. Heinlein; W. Wallace Covington; Margaret H. Moore

    2000-01-01

    Ponderosa pine forests in which frequent fire regimes continue up to the present would be invaluable points of reference for assessing natural ecological attributes. A few remote forests on the North Rim of Grand Canyon National Park come close to this ideal: never-harvested, distant from human communities and fire suppression resources, and with several low-intensity...

  3. Public feelings and environmental impacts from uranium mining inside Kakadu National Park and around Grand Canyon National Park

    International Nuclear Information System (INIS)

    McKlveen, J.W.; Kvasnicka, J.

    1989-01-01

    There are two uranium mines in the Northern Territory of Australia, Ranger and Nabarlek. The Ranger mine, the only producing operation, is located in the Kakadu National Park, which has been listed on the United Nations' World Heritage list. The park is dedicated to preserving the Australian aboriginal culture: It contains several aboriginal villages and historic sites. Uranium mining in the park has been accepted quite well by the public and the aborigines. Employees of the Ranger mine and their relatives have established a public information program that includes tours of the mining and milling operations. There is no environmental impact to the area from the mining and milling of uranium at the Ranger site. The region around the Grand Canyon contains many highgrade uranium deposits. The ore is contained in unique breccia pipe formations. The pipes, which resemble a cylinder with a diemter of ∼ 100 m and a height of ∼ 300 m, originated as limestone solution cavities located ∼ 400 m below the plateau. There are several exposed deposits along the canyon walls, but no mining operations are allowed within the park boundaries. While the real environmental impact is insignificant, the perceived impact is tremendous. Many special-interest groups have attempted to halt the mining operations. No valid environmental impacts have been predicted or observed as a result of the current mining operations. However, one mine has been delayed for religious reasons by a local tribe or native Americans

  4. Utilizing NASA Earth Observations to Assist the National Park Service in Monitoring Shoreline Land Cover Change in the Lower Grand Canyon

    Science.gov (United States)

    Stevens, C. L.; Phillips, A.; Young, S.; Counts, A.

    2017-12-01

    Sustained drought conditions have contributed to a significant decrease in the volume of the Colorado River in the Lake Mead reservoir and lower portion of the Grand Canyon. As a result, changes in riparian conditions have occurred in the region, such as sediment exposure and receding vegetation. These changes have large negative impacts on ecological health, including water and air pollution, aquatic, terrestrial and avian habitat alterations, and invasive species introduction. Scientists at Grand Canyon National Park seek to quantify changes in water surface and land cover area in the Lower Grand Canyon from 1998 to 2016 to better understand the effects of these changing conditions within the park. Landsat imagery was used to detect changes of the water surface and land cover area across this time period to assess the effects of long-term drought on the riparian zone. The resulting land cover and water surface time-series from this project will assist in monitoring future changes in water, sediment, and vegetation extent, increasing the ability of park scientists to create adaptation strategies for the ecosystem in the Lower Grand Canyon.

  5. Water quality and quantity of selected springs and seeps along the Colorado River corridor, Utah and Arizona: Arches National Park, Canyonlands National Park, Glen Canyon National Recreation Area, and Grand Canyon National Park, 1997-98

    Science.gov (United States)

    Taylor, Howard E.; Spence, John R.; Antweiler, Ronald C.; Berghoff, Kevin; Plowman, Terry I.; Peart, Dale B.; Roth, David A.

    2004-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service conducted an intensive assessment of selected springs along the Colorado River Corridor in Arches National Park, Canyonlands National Park, Glen Canyon National Recreation Area, and Grand Canyon National Park in 1997 and 1998, for the purpose of measuring and evaluating the water quality and quantity of the resource. This study was conducted to establish baseline data for the future evaluation of possible effects from recreational use and climate change. Selected springs and seeps were visited over a study period from 1997 to 1998, during which, discharge and on-site chemical measurements were made at selected springs and seeps, and samples were collected for subsequent chemical laboratory analysis. This interdisciplinary study also includes simultaneous studies of flora and fauna, measured and sampled coincidently at the same sites. Samples collected during this study were transported to U.S. Geological Survey laboratories in Boulder, Colorado, where analyses were performed using state-of-the-art laboratory technology. The location of the selected springs and seeps, elevation, geology, aspect, and onsite measurements including temperature, discharge, dissolved oxygen, pH, and specific conductance, were recorded. Laboratory analyses include determinations for alkalinity, aluminum, ammonium (nitrogen), antimony, arsenic, barium, beryllium, bismuth, boron, bromide, cadmium, calcium, cerium, cesium, chloride, chromium, cobalt, copper, dissolved inorganic carbon, dissolved organic carbon, dysprosium, erbium, europium, fluoride, gadolinium, holmium, iodine, iron, lanthanum, lead, lithium, lutetium, magnesium, manganese, mercury, molybdenum, neodymium, nickel, nitrate (nitrogen), nitrite (nitrogen), phosphate, phosphorus, potassium, praseodymium, rhenium, rubidium, samarium, selenium, silica, silver, sodium, strontium, sulfate, tellurium, terbium, thallium, thorium, thulium, tin, titanium, tungsten

  6. Grand Canyon Monitoring and Research Center

    Science.gov (United States)

    Hamill, John F.

    2009-01-01

    The Grand Canyon of the Colorado River, one of the world's most spectacular gorges, is a premier U.S. National Park and a World Heritage Site. The canyon supports a diverse array of distinctive plants and animals and contains cultural resources significant to the region's Native Americans. About 15 miles upstream of Grand Canyon National Park sits Glen Canyon Dam, completed in 1963, which created Lake Powell. The dam provides hydroelectric power for 200 wholesale customers in six western States, but it has also altered the Colorado River's flow, temperature, and sediment-carrying capacity. Over time this has resulted in beach erosion, invasion and expansion of nonnative species, and losses of native fish. Public concern about the effects of Glen Canyon Dam operations prompted the passage of the Grand Canyon Protection Act of 1992, which directs the Secretary of the Interior to operate the dam 'to protect, mitigate adverse impacts to, and improve values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established...' This legislation also required the creation of a long-term monitoring and research program to provide information that could inform decisions related to dam operations and protection of downstream resources.

  7. Topographic change detection at select archeological sites in Grand Canyon National Park, Arizona, 2007–2010

    Science.gov (United States)

    Collins, Brian D.; Corbett, Skye C.; Fairley, Helen C.; Minasian, Diane L.; Kayen, Robert; Dealy, Timothy P.; Bedford, David R.

    2012-01-01

    Human occupation in Grand Canyon, Arizona, dates from at least 11,000 years before present to the modern era. For most of this period, the only evidence of human occupation in this iconic landscape is provided by archeological sites. Because of the dynamic nature of this environment, many archeological sites are subject to relatively rapid topographic change. Quantifying the extent, magnitude, and cause of such change is important for monitoring and managing these archeological sites. Such quantification is necessary to help inform the continuing debate on whether and how controlled releases from Glen Canyon Dam, located immediately upstream of Grand Canyon National Park, are affecting site erosion rates, artifact transport, and archeological resource preservation along the Colorado River in Grand Canyon. Although long-term topographic change resulting from a variety of natural processes is inherent in the Grand Canyon region, continued erosion of archeological sites threatens both the archeological resources and our future ability to study evidence of past cultural habitation. Thus, this subject is of considerable interest to National Park Service managers and other stakeholders in the Glen Canyon Dam Adaptive Management Program. Understanding the causes and effects of archeological site erosion requires a knowledge of several factors, including the location, timing, and magnitude of the changes occurring in relation to archeological resources, the rates of change, and the relative contribution of potential causes. These potential causes include sediment depletion associated with managed flows from Glen Canyon Dam, site-specific weather and overland flow patterns, visitor impacts, and long-term regional climate change. To obtain this information, highly accurate, spatially specific data are needed from sites undergoing change. Using terrestrial lidar techniques, and building upon three previous surveys of archeological sites performed in 2006 and 2007, we

  8. Optimizing the use of on-street car parking system as a passive control of air pollution exposure in street canyons by large eddy simulation

    Science.gov (United States)

    Gallagher, J.; Gill, L. W.; McNabola, A.

    2011-03-01

    An investigation was carried out to establish the effectiveness of parked cars in urban street canyons as passive controls on pedestrian pollutant exposure. A numerical model of a generic street canyon was developed using a large eddy simulation (LES) model to compare personal exposure on the footpath with and without the presence of parked cars. Three configurations of car parking systems were investigated (parallel, perpendicular and 45° parking) in addition to the influence of wind speed, wind direction and car parking occupancy. A tracer gas (CO 2) was used as a representative pollutant from vehicular sources within the street canyon models. The results indicated that parked cars may act as a temporary baffle plate between traffic emissions and pedestrians on the footpath. Reductions in exposure of up to 35% and 49% were attained on the leeward and windward footpaths in perpendicular wind conditions, with parallel winds allowing up to 33% pollutant reduction on both footpaths for parallel parking. The perpendicular and 45° car parking configurations investigated proved less successful as passive controls on air pollution exposure and an increase in pollutant concentration occurred in some models. An investigation of parking space occupancy rates was carried out for parallel parked cars. The fraction of parked cars influenced the level of reduction of pollutants on the footpaths with steady reductions in perpendicular winds, yet reductions were only evident for occupancy rates greater than approximately 45% in parallel wind conditions. One negative impact associated with the parked cars study was the increase of pollutant levels on the roadway as the parked cars acted as a baffle wall, which trapped pollutants in the road. The paper underlines the potential of on-street car parking for reducing the personal exposure of pollutants by pedestrians and the optimum parking layout to achieve maximum health protection.

  9. AVTA federal fleet PEV readiness data logging and characterization study for the National Park Service: Grand Canyon National Park

    Energy Technology Data Exchange (ETDEWEB)

    Schey, Stephen [Intertek Testing Services, Phoenix, AZ (United States); Francfort, Jim [Idaho National Lab. (INL), Idaho Falls, ID (United States); Nienhueser, Ian [Intertek Testing Services, Phoenix, AZ (United States)

    2014-08-01

    This report focuses on the Grand Canyon National Park (GCNP) fleet to identify daily operational characteristics of select vehicles and report findings on vehicle and mission characterizations to support the successful introduction of PEVs into the agencies’ fleets. Individual observations of these selected vehicles provide the basis for recommendations related to electric vehicle adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively PEVs) can fulfill the mission requirements.

  10. Geologic map and upper Paleozoic stratigraphy of the Marble Canyon area, Cottonwood Canyon quadrangle, Death Valley National Park, Inyo County, California

    Science.gov (United States)

    Stone, Paul; Stevens, Calvin H.; Belasky, Paul; Montañez, Isabel P.; Martin, Lauren G.; Wardlaw, Bruce R.; Sandberg, Charles A.; Wan, Elmira; Olson, Holly A.; Priest, Susan S.

    2014-01-01

    This geologic map and pamphlet focus on the stratigraphy, depositional history, and paleogeographic significance of upper Paleozoic rocks exposed in the Marble Canyon area in Death Valley National Park, California. Bedrock exposed in this area is composed of Mississippian to lower Permian (Cisuralian) marine sedimentary rocks and the Jurassic Hunter Mountain Quartz Monzonite. These units are overlain by Tertiary and Quaternary nonmarine sedimentary deposits that include a previously unrecognized tuff to which we tentatively assign an age of late middle Miocene (~12 Ma) based on tephrochronologic analysis, in addition to the previously recognized Pliocene tuff of Mesquite Spring. Mississippian and Pennsylvanian rocks in the Marble Canyon area represent deposition on the western continental shelf of North America. Mississippian limestone units in the area (Tin Mountain, Stone Canyon, and Santa Rosa Hills Limestones) accumulated on the outer part of a broad carbonate platform that extended southwest across Nevada into east-central California. Carbonate sedimentation was interrupted by a major eustatic sea-level fall that has been interpreted to record the onset of late Paleozoic glaciation in southern Gondwana. Following a brief period of Late Mississippian clastic sedimentation (Indian Springs Formation), a rise in eustatic sea level led to establishment of a new carbonate platform that covered most of the area previously occupied by the Mississippian platform. The Pennsylvanian Bird Spring Formation at Marble Canyon makes up the outer platform component of ten third-order (1 to 5 m.y. duration) stratigraphic sequences recently defined for the regional platform succession. The regional paleogeography was fundamentally changed by major tectonic activity along the continental margin beginning in middle early Permian time. As a result, the Pennsylvanian carbonate shelf at Marble Canyon subsided and was disconformably overlain by lower Permian units (Osborne Canyon and

  11. The contributions of Bryce DeWitt to quantum gravity

    International Nuclear Information System (INIS)

    Isham, C.J.

    1984-01-01

    The paper reviews the work of Bryce DeWitt in the field of Quantum Gravity. Covariant commutators; R 2 lagrangians; DeWitt and Schwinger; gravity as a regulator; the full background field method; and the canonical quantization of gravity; are all discussed. (U.K.)

  12. The Pursuit of Quantum Gravity Memoirs of Bryce DeWitt from 1946 to 2004

    CERN Document Server

    DeWitt-Morette, Cécile

    2011-01-01

    1946 is the year Bryce DeWitt entered Harvard graduate school. Quantum Gravity was his goal and remained his goal throughout his lifetime until the very end. The pursuit of Quantum Gravity requires a profound understanding of Quantum Physics and Gravitation Physics. As G. A. Vilkovisky commented , "Quantum Gravity is a combination of two words, and one should know both. Bryce understood this as nobody else, and this wisdom is completely unknown to many authors of the flux of papers that we see nowadays." Distingished physicist Cecile DeWitt-Morette skillfully blends her personal and scientific account with a wealth of her late husband's often unpublished writings on the subject matter. This volume, through the perspective of the leading researcher on quantum gravity of his generation, will provide an invaluable source of reference for anyone working in the field. "I found the book both instructive and fascinating. Bryce DeWitt and Cécile DeWitt-Morette formed the most creative couple in physics that I have e...

  13. Topographic Change Detection at Select Archeological Sites in Grand Canyon National Park, Arizona, 2006-2007

    Science.gov (United States)

    Collins, Brian D.; Minasian, Diane L.; Kayen, Robert

    2009-01-01

    Topographic change of archeological sites within the Colorado River corridor of Grand Canyon National Park (GCNP) is a subject of interest to National Park Service managers and other stakeholders in the Glen Canyon Dam Adaptive Management Program. Although long-term topographic change resulting from a variety of natural processes is typical in the Grand Canyon region, a continuing debate exists on whether and how controlled releases from Glen Canyon Dam, located immediately upstream of GCNP, are impacting rates of site erosion, artifact transport, and the preservation of archeological resources. Continued erosion of archeological sites threatens both the archeological resources and our future ability to study evidence of past cultural habitation. Understanding the causes and effects of archaeological site erosion requires a knowledge of several factors including the location and magnitude of the changes occurring in relation to archeological resources, the rate of the changes, and the relative contribution of several potential causes, including sediment depletion associated with managed flows from Glen Canyon Dam, site-specific weather patterns, visitor impacts, and long-term climate change. To obtain this information, highly accurate, spatially specific data are needed from sites undergoing change. Using terrestrial lidar data collection techniques and novel TIN- and GRID-based change-detection post-processing methods, we analyzed topographic data for nine archeological sites. The data were collected using three separate data collection efforts spanning 16 months (May 2006 to September 2007). Our results documented positive evidence of erosion, deposition, or both at six of the nine sites investigated during this time interval. In addition, we observed possible signs of change at two of the other sites. Erosion was concentrated in established gully drainages and averaged 12 cm to 17 cm in depth with maximum depths of 50 cm. Deposition was concentrated at specific

  14. Channel mapping river miles 29–62 of the Colorado River in Grand Canyon National Park, Arizona, May 2009

    Science.gov (United States)

    Kaplinski, Matt; Hazel, Joseph E.; Grams, Paul E.; Kohl, Keith; Buscombe, Daniel D.; Tusso, Robert B.

    2017-03-23

    Bathymetric, topographic, and grain-size data were collected in May 2009 along a 33-mi reach of the Colorado River in Grand Canyon National Park, Arizona. The study reach is located from river miles 29 to 62 at the confluence of the Colorado and Little Colorado Rivers. Channel bathymetry was mapped using multibeam and singlebeam echosounders, subaerial topography was mapped using ground-based total-stations, and bed-sediment grain-size data were collected using an underwater digital microscope system. These data were combined to produce digital elevation models, spatially variable estimates of digital elevation model uncertainty, georeferenced grain-size data, and bed-sediment distribution maps. This project is a component of a larger effort to monitor the status and trends of sand storage along the Colorado River in Grand Canyon National Park. This report documents the survey methods and post-processing procedures, digital elevation model production and uncertainty assessment, and procedures for bed-sediment classification, and presents the datasets resulting from this study.

  15. Recreational impacts on Colorado River beaches in Glen Canyon, Arizona

    Science.gov (United States)

    Carothers, Steven W.; Johnson, Robert A.; Dolan, Robert

    1984-07-01

    Recreational impact was measured on eight beaches in Glen Canyon National Recreation Area and 15 beaches in Grand Canyon National Park using permanently located transects and plots. Recreational impact indices included densities of human trash and charcoal and a measure of sand discoloration due to charcoal. Significant increases in the indices occurred on several Glen Canyon beaches over a seven-month period. Sand discoloration became significantly higher over all Glen Canyon beaches during the same time period. All indices were significantly higher in Glen Canyon than on similar Grand Canyon beaches. These differences are probably due to differences in: (a) level of impacts tolerated by the respective management regimes and, (b) in the number of user days among the two National Park Service administrative units. Management alternatives are presented for reversing the present trends of recreational impact on Glen Canyon beaches.

  16. Demography of the California spotted owl in the Sierra National Forest and Sequoia/Kings Canyon National Parks

    Science.gov (United States)

    George N. Steger; Thomas E. Munton; Kenneth D. Johnson; Gary P. Eberlein

    2002-01-01

    Nine years (1990–1998) of demographic data on California spotted owls (Strix occidentalis occidentalis) in two study areas on the western slopes of the Sierra Nevada—one in the Sierra National Forest (SNF), the other in Sequoia/Kings Canyon National Parks (SNP)—are summarized. Numbers of territorial owls fluctuated from 85 to 50 in SNF and 80 to 58...

  17. 75 FR 10308 - Fire Management Plan, Final Environmental Impact Statement, Record of Decision, Grand Canyon...

    Science.gov (United States)

    2010-03-05

    ... DEPARTMENT OF THE INTERIOR National Park Service Fire Management Plan, Final Environmental Impact... Statement for the Fire Management Plan, Grand Canyon National Park. SUMMARY: Pursuant to the National... the Record of Decision for the Fire Management Plan, Grand Canyon National Park, Arizona. On January...

  18. Impacts of fire management on aboveground tree carbon stocks in Yosemite and Sequoia & Kings Canyon National Parks

    Science.gov (United States)

    Matchett, John R.; Lutz, James A.; Tarnay, Leland W.; Smith, Douglas G.; Becker, Kendall M.L.; Brooks, Matthew L.

    2015-01-01

    Forest biomass on Sierra Nevada landscapes constitutes one of the largest carbon stocks in California, and its stability is tightly linked to the factors driving fire regimes. Research suggests that fire suppression, logging, climate change, and present management practices in Sierra Nevada forests have altered historic patterns of landscape carbon storage, and over a century of fire suppression and the resulting accumulation in surface fuels have been implicated in contributing to recent increases in high severity, stand-replacing fires. For over 30 years, fire management at Yosemite (YOSE) and Sequoia & Kings Canyon (SEKI) national parks has led the nation in restoring fire to park landscapes; however, the impacts on the stability and magnitude of carbon stocks have not been thoroughly examined.

  19. Warm Season Storms, Floods, and Tributary Sand Inputs below Glen Canyon Dam: Investigating Salience to Adaptive Management in the Context of a 10-Year Long Controlled Flooding Experiment in Grand Canyon National Park, AZ, USA

    Science.gov (United States)

    Jain, S.; Melis, T. S.; Topping, D. J.; Pulwarty, R. S.; Eischeid, J.

    2013-12-01

    The planning and decision processes in the Glen Canyon Dam Adaptive Management Program (GCDAMP) strive to balance numerous, often competing, objectives, such as, water supply, hydropower generation, low flow maintenance, maximizing conservation of downstream tributary sand supply, endangered native fish, and other sociocultural resources of Glen Canyon National Recreation Area and Grand Canyon National Park. In this context, use of monitored and predictive information on the warm season floods (at point-to-regional scales) has been identified as lead-information for a new 10-year long controlled flooding experiment (termed the High-Flow Experiment Protocol) intended to determine management options for rebuilding and maintaining sandbars in Grand Canyon; an adaptive strategy that can potentially facilitate improved planning and dam operations. In this work, we focus on a key concern identified by the GCDAMP, related to the timing and volume of tributary sand input from the Paria and Little Colorado Rivers (located 26 and 124 km below the dam, respectively) into the Colorado River in Grand Canyon National Park. Episodic and intraseasonal variations (with links to equatorial and sub-tropical Pacific sea surface temperature variability) in the southwest hydroclimatology are investigated to understand the magnitude, timing and spatial scales of warm season floods from this relatively small, but prolific sand producing drainage of the semi-arid Colorado Plateau. The coupled variations of the flood-driven sediment input (magnitude and timing) from these two drainages into the Colorado River are also investigated. The physical processes, including diagnosis of storms and moisture sources, are mapped alongside the planning and decision processes for the ongoing experimental flood releases from the Glen Canyon Dam which are aimed at achieving restoration and maintenance of sandbars and instream ecology. The GCDAMP represents one of the most visible and widely recognized

  20. Bryce Canyon National Park: Hoodoos Cast Their Spell. Teaching with Historic Places.

    Science.gov (United States)

    Shakespear, Mala

    Surrounded by the beauty of southern Utah and panoramic views of three states, filigrees of colorful stones that erosion has shaped into a spectacular array of spires, fins, and pinnacles called "hoodoos" remind tourist viewers of church steeples, Gothic spires, castle walls, animals, and even people. In this lesson students explore why…

  1. Red Rock Canyon National Conservation Area Transportation Feasibility Study

    Science.gov (United States)

    2012-07-31

    Red Rock Canyon National Conservation Area is a popular Bureau of Land Management natural area located near Las Vegas, Nevada. Red Rock Canyon experiences heavy congestion on its Scenic Drive and associated parking areas, due to high volumes of visit...

  2. The pursuit of quantum gravity. Memoirs of Bryce DeWitt from 1946 to 2004

    International Nuclear Information System (INIS)

    DeWitt-Morette, Cecile

    2011-01-01

    1946 is the year Bryce DeWitt entered Harvard graduate school. Quantum Gravity was his goal and remained his goal throughout his lifetime until the very end. The pursuit of Quantum Gravity requires a profound understanding of Quantum Physics and Gravitation Physics. As G. A. Vilkovisky commented, ''Quantum Gravity is a combination of two words, and one should know both. Bryce understood this as nobody else, and this wisdom is completely unknown to many authors of the flux of papers that we see nowadays.'' Distinguished physicist Cecile DeWitt-Morette skillfully blends her personal and scientific account with a wealth of her late husband's often unpublished writings on the subject matter. This volume, through the perspective of the leading researcher on quantum gravity of his generation, will provide an invaluable source of reference for anyone working in the field. (orig.)

  3. Retorcer el tiempo: Fernando Bryce y el arte de historia = Twisting the time: Fernando Bryce’s art of history

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Hernández Navarro

    2016-06-01

    Full Text Available Durante las últimas dos décadas, toda una generación de artistas se ha interesado por el pasado actuando como virtuales historiadores: investigando, trabajando con documentos primarios y promoviendo visiones críticas de la historia. Este artículo examina la obra del artista peruano Fernando Bryce bajo ese prisma del «arte de historia». A través de un particular método de trabajo, que el artista ha llamado «análisis mimético», Bryce reflexiona sobre la construcción de la historia, la geopolítica, la identidad en Latinoamérica, sobre todo en Perú, los conflictos bélicos del siglo XX o incluso de la vigencia y genealogía del pensamiento revolucionario. Con una estética aparentemente de archivo, Bryce selecciona documentos que posteriormente copia en tinta china sobre papel para construir nuevas lecturas de la historia. Su selección, descontextualización, visualización de historias pasadas y olvidadas contribuye a traer el pasado al presente. Y su método de trabajo –el copiado anacrónico de documentos, la performance de la historia, su repetición «trastornada»– retuerce el tiempo y cuestiona los discursos hegemónicos acerca del pasado.Over the last two decades, a whole generation of artists approach to the past as if they themselves were historians: investigating, working with primary documents and promoting a critical engagement with history. This article considers the work of Peruvian artist Fernando Bryce through the prism of this «art of history». Using a particular work method—which the artist has dubbed «Mimetic analysis»—Bryce reflects on the construction of history, geopolitics, identity in Latin America, particularly in Peru, the armed conflicts of the 20th century or even the validity and genealogy of revolutionary thinking. With an archive-like aesthetics, Bryce selects documents that he subsequently copies in ink on paper in order to construct new readings of history. His selection

  4. Yellowcake National Park

    International Nuclear Information System (INIS)

    Dagget, D.

    1985-01-01

    Exploration for and mining of uranium ore is going on within 10 miles of the Grand Canyon National Park. The current rush started in 1980, when a Denver-based company, Energy Fuels Nuclear, took over a claim in Hack Canyon and uncovered a very rich deposit of uranium ore. Recent explorations have resulted in some 1300 claims in the area around the Grand Canyon, many of them in the Arizona Strip, the land between the Canyon and Utah. The center of current controversy is the 1872 Mining Law. Replacement of the law with a leasing system similar to that used for leasable minerals such as coal, oil shale, oil and gas, potash, and phosphate is advocated. 1 figure

  5. Utah Valley University Field Station at Capitol Reef National Park: A Venue for Improved Student Learning and Retention

    Science.gov (United States)

    Nielsen, K.; Schultz, M.; Williams, B.; Gay, J.; Johnson, S.; Dunn, P.

    2015-12-01

    The unique geo-environment offered in Capitol Reef National Park and its surrounding areas has a long-standing history of inspiring geological scientific exploration. The Capitol Reef Field Station was established in 2008 as part of collaboration between the National Park and Utah Valley University in order to support teaching and research of the natural environment found within the park and on the Colorado Plateau. The facility itself situated deep within the park, well off any public road system offers state of the art alternative energy and sustainable construction and makes extensive use of passive heating and cooling, in order to maintain its status of being "off-grid." The field station is a 6200 square foot complex of classrooms and dormitories supporting university level education and field studies of the Colorado Plateau. The complex includes a classroom and dining area, professional kitchen, and two separate dormitories, which can sleep up to 24 overnight visitors, while the daytime usage can accommodate up to 40 visitors. The vision of the facility is to support teaching and research toward responsible, respectful, and sustainable stewardship of the natural world - including Interdisciplinary learning between arts and sciences Student internships and service learning in collaboration with the National Park Service Field-based scientific research (as well as inventorying and assessing Park ecosystems changes) Field training in scientific research Collaboration between National Park Service scientists and local, regional, and national institutions The park is situated at 38°N 249°E at elevations greater than 2000 m in Southern Utah. In contrast to the more famous neighboring sister parks such as Zion and Bryce Canyon National Parks, which are in relatively close proximity to large road systems and cities, Capitol Reef offers what is believed to be the darkest night sky in the US. The culmination of features creates an ideal location for studies of the

  6. AUV Mapping and ROV Exploration of Los Frailes Submarine Canyon, Cabo Pulmo National Marine Park, Baja California Sur, Mexico

    Science.gov (United States)

    Troni, G.; Caress, D. W.; Graves, D.; Thomas, H. J.; Thompson, D.; Barry, J. P.; Aburto-Oropeza, O.; Johnson, A. F.; Lundsten, L.

    2015-12-01

    Los Frailes submarine canyon is located at the south boundary of the Cabo Pulmo National Marine Park on the southeast tip of the Baja California Peninsula. During the Monterey Bay Aquarium Research Institute (MBARI) 2015 Gulf of California expedition we used an autonomous underwater vehicle (AUV) to map this canyon from 50 m to 450 m depths, and then explored the canyon with a small remotely operated vehicle (ROV). This three day R/V Rachel Carson cruise was a collaboration with the Center for Marine Biodiversity and Conservation at Scripps Institution of Oceanography and the Centro para la Biodiversidad Marina y la Conservación in La Paz. The MBARI AUV D. Allan B. collected high resolution bathymetry, sidescan, and subbottom profiles of Los Frailes submarine canyon and part of the north Cabo Pulmo deep reef. In order to safely generate a 1-m lateral resolution multibeam bathymetry map in the nearshore high relief terrain, the mapping operations consisted of an initial short survey following the 100-m isobath followed by a series of short, incremental AUV missions located on the deep edge of the new AUV bathymetry. The MBARI Mini-ROV was used to explore the submarine canyon within the detailed map created by the MBARI AUV. The Mini-ROV is a 1.2-m-long, 350 kg, 1,500-m-depth-rated ROV designed and constructed by MBARI. It is controlled by six 600-watt thrusters and is equipped with a high-definition video camera and navigation sensors. This small ROV carries less accurate, lower cost navigation sensors than larger vehicles. We implemented new algorithms to localize combining Doppler velocity log sensor data and low-cost MEMS-based inertial sensor data with sporadic ultra-short baseline position measurements to provide a high accuracy position estimation. The navigation performance allowed us to colocate the ROV video imagery with the 1-m resolution bathymetric map of the submarine canyon. Upper Los Frailes Canyon is rugged and, aside from small sand pockets along

  7. Decision Support System for Evaluation of Gunnison River Flow Regimes With Respect To Resources of the Black Canyon of the Gunnison National Park

    Science.gov (United States)

    Auble, Gregor T.; Wondzell, Mark; Talbert, Colin

    2009-01-01

    This report describes and documents a decision support system for the Gunnison River in Black Canyon of the Gunnison National Park. It is a macro-embedded EXCEL program that calculates and displays indicators representing valued characteristics or processes in the Black Canyon based on daily flows of the Gunnison River. The program is designed to easily accept input from downloaded stream gage records or output from the RIVERWARE reservoir operations model being used for the upstream Aspinall Unit. The decision support system is structured to compare as many as eight alternative flow regimes, where each alternative is represented by a daily sequence of at least 20 calendar years of streamflow. Indicators include selected flow statistics, riparian plant community distribution, clearing of box elder by inundation and scour, several measures of sediment mobilization, trout fry habitat, and federal reserved water rights. Calculation of variables representing National Park Service federal reserved water rights requires additional secondary input files pertaining to forecast and actual basin inflows and storage levels in Blue Mesa reservoir. Example input files representing a range of situations including historical, reconstructed natural, and simulated alternative reservoir operations are provided with the software.

  8. 2008 High-Flow Experiment at Glen Canyon Dam-Morphologic Response of Eddy-Deposited Sandbars and Associated Aquatic Backwater Habitats along the Colorado River in Grand Canyon National Park

    Science.gov (United States)

    Grams, Paul E.; Schmidt, John C.; Andersen, Matthew E.

    2010-01-01

    The March 2008 high-flow experiment (HFE) at Glen Canyon Dam resulted in sandbar deposition and sandbar reshaping such that the area and volume of associated backwater aquatic habitat in Grand Canyon National Park was greater following the HFE. Analysis of backwater habitat area and volume for 116 locations at 86 study sites, comparing one month before and one month after the HFE, shows that total habitat area increased by 30 percent to as much as a factor of 3 and that volume increased by 80 percent to as much as a factor of 15. These changes resulted from an increase in the area and elevation of sandbars, which isolate backwaters from the main channel, and the scour of eddy return-current channels along the bank where the habitat occurs. Because of this greater relief on the sandbars, backwaters were present across a broader range of flows following the HFE than before the experiment. Reworking of sandbars during diurnal fluctuating flow operations in the first 6 months following the HFE caused sandbar erosion and a reduction of backwater size and abundance to conditions that were 5 to 14 percent greater than existed before the HFE. In the months following the HFE, erosion of sandbars and deposition in eddy return-current channels caused reductions of backwater area and volume. However, sandbar relief was still greater in October 2008 such that backwaters were present across a broader range of discharges than in February 2008. Topographic analyses of the sandbar and backwater morphologic data collected in this study demonstrate that steady flows are associated with a greater amount of continuously available backwater habitat than fluctuating flows, which result in a greater amount of intermittently available habitat. With the exception of the period immediately following the HFE, backwater habitat in 2008 was greater for steady flows associated with dam operations of relatively lower monthly volume (about 227 m3/s) than steady flows associated with dam operations

  9. 36 CFR 7.4 - Grand Canyon National Park.

    Science.gov (United States)

    2010-07-01

    ... point of origin of the tour, will be accorded admission to the park. (b) Colorado whitewater boat trips... conduct of a commercial or business activity in the park. (iii) An operation is commercial if any fee... will not interfere with park management or impair park resources. (i) Any permit issued will be valid...

  10. Estimating the spatial and temporal distribution of species richness within Sequoia and Kings Canyon National Parks.

    Directory of Open Access Journals (Sweden)

    Steve Wathen

    Full Text Available Evidence for significant losses of species richness or biodiversity, even within protected natural areas, is mounting. Managers are increasingly being asked to monitor biodiversity, yet estimating biodiversity is often prohibitively expensive. As a cost-effective option, we estimated the spatial and temporal distribution of species richness for four taxonomic groups (birds, mammals, herpetofauna (reptiles and amphibians, and plants within Sequoia and Kings Canyon National Parks using only existing biological studies undertaken within the Parks and the Parks' long-term wildlife observation database. We used a rarefaction approach to model species richness for the four taxonomic groups and analyzed those groups by habitat type, elevation zone, and time period. We then mapped the spatial distributions of species richness values for the four taxonomic groups, as well as total species richness, for the Parks. We also estimated changes in species richness for birds, mammals, and herpetofauna since 1980. The modeled patterns of species richness either peaked at mid elevations (mammals, plants, and total species richness or declined consistently with increasing elevation (herpetofauna and birds. Plants reached maximum species richness values at much higher elevations than did vertebrate taxa, and non-flying mammals reached maximum species richness values at higher elevations than did birds. Alpine plant communities, including sagebrush, had higher species richness values than did subalpine plant communities located below them in elevation. These results are supported by other papers published in the scientific literature. Perhaps reflecting climate change: birds and herpetofauna displayed declines in species richness since 1980 at low and middle elevations and mammals displayed declines in species richness since 1980 at all elevations.

  11. Evaluation of Terrestrial LIDAR for Monitoring Geomorphic Change at Archeological Sites in Grand Canyon National Park, Arizona

    Science.gov (United States)

    Collins, Brian D.; Brown, Kristin M.; Fairley, Helen C.

    2008-01-01

    This report presents the results of an evaluation of terrestrial light detection and ranging (LIDAR) for monitoring geomorphic change at archeological sites located within Grand Canyon National Park, Ariz. Traditionally, topographic change-detection studies have used total station methods for the collection of data related to key measurable features of site erosion such as the location of thalwegs and knickpoints of gullies that traverse archeological sites (for example, Pederson and others, 2003). Total station methods require survey teams to walk within and on the features of interest within the archeological sites to take accurate measurements. As a result, site impacts may develop such as trailing, damage to cryptogamic crusts, and surface compaction that can exacerbate future erosion of the sites. National Park Service (NPS) resource managers have become increasingly concerned that repeated surveys for research and monitoring purposes may have a detrimental impact on the resources that researchers are trying to study and protect. Beginning in 2006, the Sociocultural Program of the U.S. Geological Survey's (USGS) Grand Canyon Monitoring and Research Center (GCMRC) initiated an evaluation of terrestrial LIDAR as a new monitoring tool that might enhance data quality and reduce site impacts. This evaluation was conducted as one part of an ongoing study to develop objective, replicable, quantifiable monitoring protocols for tracking the status and trend of variables affecting archeological site condition along the Colorado River corridor. The overall study consists of two elements: (1) an evaluation of the methodology through direct comparison to geomorphologic metrics already being collected by total station methods (this report) and (2) an evaluation of terrestrial LIDAR's ability to detect topographic change through the collection of temporally different datasets (a report on this portion of the study is anticipated early in 2009). The main goals of the first

  12. Regional economic impacts of Grand Canyon river runners.

    Science.gov (United States)

    Hjerpe, Evan E; Kim, Yeon-Su

    2007-10-01

    Economic impact analysis (EIA) of outdoor recreation can provide critical social information concerning the utilization of natural resources. Outdoor recreation and other non-consumptive uses of resources are viewed as environmentally friendly alternatives to extractive-type industries. While outdoor recreation can be an appropriate use of resources, it generates both beneficial and adverse socioeconomic impacts on rural communities. The authors used EIA to assess the regional economic impacts of rafting in Grand Canyon National Park. The Grand Canyon region of northern Arizona represents a rural US economy that is highly dependent upon tourism and recreational expenditures. The purpose of this research is twofold. The first is to ascertain the previously unknown regional economic impacts of Grand Canyon river runners. The second purpose is to examine attributes of these economic impacts in terms of regional multipliers, leakage, and types of employment created. Most of the literature on economic impacts of outdoor recreation has focused strictly on the positive economic impacts, failing to illuminate the coinciding adverse and constraining economic impacts. Examining the attributes of economic impacts can highlight deficiencies and constraints that limit the economic benefits of recreation and tourism. Regional expenditure information was obtained by surveying non-commercial boaters and commercial outfitters. The authors used IMPLAN input-output modeling to assess direct, indirect, and induced effects of Grand Canyon river runners. Multipliers were calculated for output, employment, and income. Over 22,000 people rafted on the Colorado River through Grand Canyon National Park in 2001, resulting in an estimated $21,100,000 of regional expenditures to the greater Grand Canyon economy. However, over 50% of all rafting-related expenditures were not captured by the regional economy and many of the jobs created by the rafting industry are lower-wage and seasonal. Policy

  13. A sand budget for Marble Canyon, Arizona: implications for long-term monitoring of sand storage change

    Science.gov (United States)

    Grams, Paul E.

    2013-01-01

    Recent U.S. Geological Survey research is providing important insights into how best to monitor changes in the amount of tributary-derived sand stored on the bed of the Colorado River and in eddies in Marble Canyon, Arizona. Before the construction of Glen Canyon Dam and other dams upstream, sandbars in Glen, Marble, and Grand Canyons were replenished each year by sediment-rich floods. Sand input into the Colorado River is crucial to protecting endangered native fish, animals, and plants and cultural and recreational resources along the river in Glen Canyon National Recreation Area and Grand Canyon National Park.

  14. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern

    Science.gov (United States)

    Huber, Ann; Das, Adrian; Wenk, Rebecca; Haultain, Sylvia

    2013-01-01

    Sequoia and Kings Canyon National Parks are located in the California Floristic Province, which has been named one of world‘s hotspots of endemic biodiversity (Myers et al. 2000). The California Floristic Province is the largest and most important geographic floristic unit in California and extends from the Klamath Mountains of southwestern Oregon to the northwestern portion of Baja California (Hickman 1993). The Sierra Nevada, one of six regions that make up the California Floristic Province, covers nearly 20% of the land in California yet contains over 50% of its flora. Within the Sierra Nevada, the southern Sierra supports more Sierran endemic and rare plant taxa than the central and northern portions of the region (Shevock 1996). Sequoia and Kings Canyon National Parks (SEKI) encompass roughly 20% of the southern Sierra Nevada region. The parks overlap three floristic subregions (central Sierra Nevada High, southern Sierra Nevada High, and southern Sierra Nevada Foothills), and border the Great Basin Floristic Province. The parks support a rich and diverse vascular flora composed of over 1,560 taxa. Of these, 150 taxa are identified as having special status. The term special status is applied here to include taxa that are state or federally listed, rare in California, or at risk because they have a limited distribution. Only one species from these parks is listed under the state or federal Endangered Species Acts (Carex tompkinsii, Tompkins‘ sedge, is listed as a rare species under the California Endangered Species Act), and one species is under review for federal endangered listing (Pinus albicaulis, whitebark pine). However, an absence of threatened and endangered species recognized by Endangered Species Acts is not equivalent to an absence of species at risk. There are 83 plant taxa documented as occurring in SEKI that are considered imperiled or vulnerable in the state by the California Department of Fish and Game‘s California Natural Diversity

  15. Standardized methods for Grand Canyon fisheries research 2015

    Science.gov (United States)

    Persons, William R.; Ward, David L.; Avery, Luke A.

    2013-01-01

    This document presents protocols and guidelines to persons sampling fishes in the Grand Canyon, to help ensure consistency in fish handling, fish tagging, and data collection among different projects and organizations. Most such research and monitoring projects are conducted under the general umbrella of the Glen Canyon Dam Adaptive Management Program and include studies by the U.S. Geological Survey (USGS), U.S. Fish and Wildlife Service (FWS), National Park Service (NPS), the Arizona Game and Fish Department (AGFD), various universities, and private contractors. This document is intended to provide guidance to fieldworkers regarding protocols that may vary from year to year depending on specific projects and objectives. We also provide herein documentation of standard methods used in the Grand Canyon that can be cited in scientific publications, as well as a summary of changes in protocols since the document was first created in 2002.

  16. Haze in the Grand Canyon: An evaluation of the Winter Haze Intensive Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    The Grand Canyon is one of the most spectacular natural sights on earth. Approximately 4 million visitors travel to Grand Canyon National Park (GCNP) each year to enjoy its majestic geological formations and intensely colored views. However, visibility in GCNP can be impaired by small increases in concentrations of fine suspended particles that scatter and absorb light; the resulting visibility degradation is perceived as haze. Sulfate particles are a major factor in visibility impairment at Grand Canyon in summer and winter. Many wintertime hazes at GCNP are believed to result from the accumulation of emissions from local sources during conditions of air stagnation, which occur more frequently in winter than in summer. In January and February 1987, the National Park Service (NPS) carried out a large-scale experiment known as the Winter Haze Intensive Tracer Experiment (WHITEX) to investigate the causes of wintertime haze in the region of GCNP and Canyonlands National Park. The overall objective of WHITEX was to assess the feasibility of attributing visibility impairment in specific geographic regions to emissions from a single point source. The experiment called for the injection of a tracer, deuterated methane (CD{sub 4}), into one of the stacks of the Navajo Generating Station (NGS), a major coal-fired power plant located 25 km from the GCNP boundary and 110 km northeast of Grand Canyon Village. A network of field stations was established in the vicinity -- mostly to the northeast of GCNP and NGS -- to measure CD{sub 4} concentrations, atmospheric aerosol and optical properties, and other chemical and physical attributes. 19 refs., 3 figs.

  17. 77 FR 55829 - Western Area Power Administration; Grapevine Canyon Wind Project Record of Decision (DOE/EIS-0427)

    Science.gov (United States)

    2012-09-11

    ... DEPARTMENT OF ENERGY Western Area Power Administration; Grapevine Canyon Wind Project Record of... one or more phases, dependent on one or more power sale contracts. The proposed wind park would... that limit construction vehicle speed limits. Foresight indicated that the wind park contractor will...

  18. 36 CFR 7.8 - Sequoia and Kings Canyon National Parks.

    Science.gov (United States)

    2010-07-01

    ... National Parks. (a) Dogs and cats. Dogs and cats are prohibited on any park land or trail except within one-fourth mile of developed areas which are accessible by a designated public automobile road. (b) Fishing. (1) Fishing restrictions, based on management objectives described in the parks' Resources Management...

  19. Modern landscape processes affecting archaeological sites along the Colorado River corridor downstream of Glen Canyon Dam, Glen Canyon National Recreation Area, Arizona

    Science.gov (United States)

    East, Amy E.; Sankey, Joel B.; Fairley, Helen C.; Caster, Joshua J.; Kasprak, Alan

    2017-08-29

    The landscape of the Colorado River through Glen Canyon National Recreation Area formed over many thousands of years and was modified substantially after the completion of Glen Canyon Dam in 1963. Changes to river flow, sediment supply, channel base level, lateral extent of sedimentary terraces, and vegetation in the post-dam era have modified the river-corridor landscape and have altered the effects of geologic processes that continue to shape the landscape and its cultural resources. The Glen Canyon reach of the Colorado River downstream of Glen Canyon Dam hosts many archaeological sites that are prone to erosion in this changing landscape. This study uses field evaluations from 2016 and aerial photographs from 1952, 1973, 1984, and 1996 to characterize changes in potential windblown sand supply and drainage configuration that have occurred over more than six decades at 54 archaeological sites in Glen Canyon and uppermost Marble Canyon. To assess landscape change at these sites, we use two complementary geomorphic classification systems. The first evaluates the potential for aeolian (windblown) transport of river-derived sand from the active river channel to higher elevation archaeological sites. The second identifies whether rills, gullies, or arroyos (that is, overland drainages that erode the ground surface) exist at the archaeological sites as well as the geomorphic surface, and therefore the relative base level, to which those flow paths drain. Results of these assessments are intended to aid in the management of irreplaceable archaeological resources by the National Park Service and stakeholders of the Glen Canyon Dam Adaptive Management Program.

  20. Characterizing local traffic contributions to particulate air pollution in street canyons using mobile monitoring techniques

    Science.gov (United States)

    Zwack, Leonard M.; Paciorek, Christopher J.; Spengler, John D.; Levy, Jonathan I.

    2011-05-01

    Traffic within urban street canyons can contribute significantly to ambient concentrations of particulate air pollution. In these settings, it is challenging to separate within-canyon source contributions from urban and regional background concentrations given the highly variable and complex emissions and dispersion characteristics. In this study, we used continuous mobile monitoring of traffic-related particulate air pollutants to assess the contribution to concentrations, above background, of traffic in the street canyons of midtown Manhattan. Concentrations of both ultrafine particles (UFP) and fine particles (PM 2.5) were measured at street level using portable instruments. Statistical modeling techniques accounting for autocorrelation were used to investigate the presence of spatial heterogeneity of pollutant concentrations as well as to quantify the contribution of within-canyon traffic sources. Measurements were also made within Central Park, to examine the impact of offsets from major roadways in this urban environment. On average, an approximate 11% increase in concentrations of UFP and 8% increase in concentrations of PM 2.5 over urban background was estimated during high-traffic periods in street canyons as opposed to low traffic periods. Estimates were 8% and 5%, respectively, after accounting for temporal autocorrelation. Within Central Park, concentrations were 40% higher than background (5% after accounting for temporal autocorrelation) within the first 100 m from the nearest roadway for UFP, with a smaller but statistically significant increase for PM 2.5. Our findings demonstrate the viability of a mobile monitoring protocol coupled with spatiotemporal modeling techniques in characterizing local source contributions in a setting with street canyons.

  1. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 22: climatic change

    Science.gov (United States)

    Das, Adrian J.; Stephenson, Nathan L.

    2013-01-01

    weather stations, like SEKI, the addition or subtraction of even a single weather station through time has the potential to significantly bias trends in interpolated data. In particular, this analysis was motivated by our questioning of some PRISM results presented in Appendix 1 (Landscape Context) that compared temperature averages between two 30-year periods of the 20th Century. Figures 6 and 11 of Appendix 1 indicate that recent (1971-2000) temperatures in northern Kings Canyon National Park averaged some 2° C cooler than those of 1911-1940. This would represent a truly profound and persistent cooling, and seems to be at odds both with the glacial retreats observed in the area over the century (Basagic 2008), and with the reported PRISM warming of nearly 2° C just to the west of the cooling (see Figs. 6 and 11 in Appendix 1). We suspect that the extreme localized Kings Canyon cooling reported by PRISM is an artifact of sparsely-distributed weather stations in the region being added and discontinued over the span of the 20th Century. For example, data from the Western Regional Climate Center (http://www.wrcc.dri.edu/coopmap/) suggest that for the period 1911 through 1924 PRISM must interpolate northern Kings Canyon temperatures based on a few low-elevation stations -- separated by hundreds of kilometers -- in Nevada and California’s San Joaquin Valley. In contrast, by 1970 PRISM interpolations will be dominated by closer, higher-elevation stations (see this report). The single weather station closest to northern Kings Canyon that has a temperature record at least partly spanning Appendix 1’s two

  2. A reconnaissance of the effects of a forest fire on water quality in Kings Canyon National Park, California

    Science.gov (United States)

    Hoffman, Ray J.; Ferreira, Rodger F.

    1976-01-01

    Following two forest fires in the Roaring River drainage basin, Kings Canyon National Park, Calif., water samples were collected from May to July 1974 to determine water-quality changes resulting from the fires. Field measurements included alkalinity , pH, specific conductance, temperature, and discharge. Samples were analyzed in the laboratory for major dissolved chemical constituents, selected plant nutrients, trace metals, suspended sediment, total organic carbon, and seston. Periphytic algae and benthic invertebrate samples were collected. A noticeable increase in the concentration of nitrogen was found in Roaring River immediately downstream from the Moraine Creek fire. The increase in the concentration of inorganic nitrogen compounds, however, was not great enough to pose a serious threat to the aquatic ecosystem. High total organic nitrogen concentrations may have been due, in part, to factors other than the effect of fire. The results of other water-quality measurements were typical of dilute Sierra Nevada streams and indicate that Roaring River was not adversely affected by the fires. (Woodard-USGS)

  3. The effects of wildfire on the peak streamflow magnitude and frequency, Frijoles and Capulin Canyons, Bandelier National Monument, New Mexico

    Science.gov (United States)

    Veenhuis, J.E.

    2004-01-01

    In June of 1977, the La Mesa fire burned 15,270 acres in and around Frijoles Canyon, Bandelier National Monument and the adjacent Santa Fe National Forest, New Mexico. The Dome fire occurred in April of 1996 in Bandelier National Monument, burned 16,516 acres in Capulin Canyon and the surrounding Dome Wilderness area. Both canyons are characterized by extensive archeological artifacts, which could be threatened by increased runoff and accelerated rates of erosion after a wildfire. The U.S. Geological Survey (USGS) in cooperation with the National Park Service monitored the fires' effects on streamflow in both canyons. Copyright 2004 ASCE.

  4. An analysis of background noise in selected canyons of Los Alamos County

    Energy Technology Data Exchange (ETDEWEB)

    Huchton, K.; Koch, S.W.; Robinson, R.

    1997-10-01

    The authors recorded background noise levels in six canyons within Los Alamos County in order to establish a baseline for future comparisons and to discover what noises animals are exposed to. Noise level measurements were taken within each canyon, beginning at an established starting point and at one-mile intervals up to four miles. The primary source of noise above 55 dBA was vehicular traffic. One clap of thunder provided the highest recorded noise level (76 dBA). In general, the level of noise, once away from highways and parking lots, was well below 60 dBA.

  5. Assessing the risk of foliar injury from ozone on vegetation in parks in the U.S. National Park Service's Vital Signs Network

    International Nuclear Information System (INIS)

    Kohut, Robert

    2007-01-01

    The risk of ozone injury to plants was assessed in support of the National Park Service's Vital Signs Monitoring Network program. The assessment examined bioindicator species, evaluated levels of ozone exposure, and investigated soil moisture conditions during periods of exposure for a 5-year period in each park. The assessment assigned each park a risk rating of high, moderate, or low. For the 244 parks for which assessments were conducted, the risk of foliar injury was high in 65 parks, moderate in 46 parks, and low in 131 parks. Among the well-known parks with a high risk of ozone injury are Gettysburg, Valley Forge, Delaware Water Gap, Cape Cod, Fire Island, Antietam, Harpers Ferry, Manassas, Wolf Trap Farm Park, Mammoth Cave, Shiloh, Sleeping Bear Dunes, Great Smoky Mountains, Joshua Tree, Sequoia and Kings Canyon, and Yosemite. - An assessment of the risk of foliar ozone injury on plants was conducted for 269 parks in support of the U.S. National Park Service's Vital Signs Monitoring Network Program

  6. A lightning multiple casualty incident in Sequoia and Kings Canyon National Parks.

    Science.gov (United States)

    Spano, Susanne J; Campagne, Danielle; Stroh, Geoff; Shalit, Marc

    2015-03-01

    Multiple casualty incidents (MCIs) are uncommon in remote wilderness settings. This is a case report of a lightning strike on a Boy Scout troop hiking through Sequoia and Kings Canyon National Parks (SEKI), in which the lightning storm hindered rescue efforts. The purpose of this study was to review the response to a lightning-caused MCI in a wilderness setting, address lightning injury as it relates to field management, and discuss evacuation options in inclement weather incidents occurring in remote locations. An analysis of SEKI search and rescue data and a review of current literature were performed. A lightning strike at 10,600 feet elevation in the Sierra Nevada Mountains affected a party of 5 adults and 7 Boy Scouts (age range 12 to 17 years old). Resources mobilized for the rescue included 5 helicopters, 2 ambulances, 2 hospitals, and 15 field and 14 logistical support personnel. The incident was managed from strike to scene clearance in 4 hours and 20 minutes. There were 2 fatalities, 1 on scene and 1 in the hospital. Storm conditions complicated on-scene communication and evacuation efforts. Exposure to ongoing lightning and a remote wilderness location affected both victims and rescuers in a lightning MCI. Helicopters, the main vehicles of wilderness rescue in SEKI, can be limited by weather, daylight, and terrain. Redundancies in communication systems are vital for episodes of radio failure. Reverse triage should be implemented in lightning injury MCIs. Education of both wilderness travelers and rescuers regarding these issues should be pursued. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  7. 78 FR 38072 - General Management Plan, Final Environmental Impact Statement, Guadalupe Mountains National Park...

    Science.gov (United States)

    2013-06-25

    ...[aacute]squez, at the Park Headquarters/Pine Springs Visitor Center: 400 Pine Canyon Drive, Salt Flat, TX...]squez, Superintendent, Guadalupe Mountains National Park, HC 60, Box 400, Salt Flat, TX 79847-9400.... Campsites and horse corrals would be closed and their sites revegetated. The limited amount of new...

  8. A Vegetation Database for the Colorado River Ecosystem from Glen Canyon Dam to the Western Boundary of Grand Canyon National Park, Arizona

    Science.gov (United States)

    Ralston, Barbara E.; Davis, Philip A.; Weber, Robert M.; Rundall, Jill M.

    2008-01-01

    A vegetation database of the riparian vegetation located within the Colorado River ecosystem (CRE), a subsection of the Colorado River between Glen Canyon Dam and the western boundary of Grand Canyon National Park, was constructed using four-band image mosaics acquired in May 2002. A digital line scanner was flown over the Colorado River corridor in Arizona by ISTAR Americas, using a Leica ADS-40 digital camera to acquire a digital surface model and four-band image mosaics (blue, green, red, and near-infrared) for vegetation mapping. The primary objective of this mapping project was to develop a digital inventory map of vegetation to enable patch- and landscape-scale change detection, and to establish randomized sampling points for ground surveys of terrestrial fauna (principally, but not exclusively, birds). The vegetation base map was constructed through a combination of ground surveys to identify vegetation classes, image processing, and automated supervised classification procedures. Analysis of the imagery and subsequent supervised classification involved multiple steps to evaluate band quality, band ratios, and vegetation texture and density. Identification of vegetation classes involved collection of cover data throughout the river corridor and subsequent analysis using two-way indicator species analysis (TWINSPAN). Vegetation was classified into six vegetation classes, following the National Vegetation Classification Standard, based on cover dominance. This analysis indicated that total area covered by all vegetation within the CRE was 3,346 ha. Considering the six vegetation classes, the sparse shrub (SS) class accounted for the greatest amount of vegetation (627 ha) followed by Pluchea (PLSE) and Tamarix (TARA) at 494 and 366 ha, respectively. The wetland (WTLD) and Prosopis-Acacia (PRGL) classes both had similar areal cover values (227 and 213 ha, respectively). Baccharis-Salix (BAXX) was the least represented at 94 ha. Accuracy assessment of the

  9. Assessing the risk of foliar injury from ozone on vegetation in parks in the U.S. National Park Service's Vital Signs Network

    Energy Technology Data Exchange (ETDEWEB)

    Kohut, Robert [Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853 (United States)], E-mail: rjk9@cornell.edu

    2007-10-15

    The risk of ozone injury to plants was assessed in support of the National Park Service's Vital Signs Monitoring Network program. The assessment examined bioindicator species, evaluated levels of ozone exposure, and investigated soil moisture conditions during periods of exposure for a 5-year period in each park. The assessment assigned each park a risk rating of high, moderate, or low. For the 244 parks for which assessments were conducted, the risk of foliar injury was high in 65 parks, moderate in 46 parks, and low in 131 parks. Among the well-known parks with a high risk of ozone injury are Gettysburg, Valley Forge, Delaware Water Gap, Cape Cod, Fire Island, Antietam, Harpers Ferry, Manassas, Wolf Trap Farm Park, Mammoth Cave, Shiloh, Sleeping Bear Dunes, Great Smoky Mountains, Joshua Tree, Sequoia and Kings Canyon, and Yosemite. - An assessment of the risk of foliar ozone injury on plants was conducted for 269 parks in support of the U.S. National Park Service's Vital Signs Monitoring Network Program.

  10. Critical Loads of Atmospheric Nitrogen Deposition for Aquatic Ecosystems in Yosemite and Sequoia and Kings Canyon National Parks

    Science.gov (United States)

    Nanus, L.; Clow, D. W.; Sickman, J. O.

    2016-12-01

    High-elevation aquatic ecosystems in Yosemite (YOSE) and Sequoia and Kings Canyon (SEKI) National Parks are impacted by atmospheric nitrogen (N) deposition associated with local and regional air pollution. Documented effects include elevated surface water nitrate concentrations, increased algal productivity, and changes in diatom species assemblages. Annual wet inorganic N deposition maps, developed at 1-km resolution for YOSE and SEKI to quantify N deposition to sensitive high-elevation ecosystems, range from 1.0 to over 5.0 kg N ha-1 yr-1. Critical loads of N deposition for nutrient enrichment of aquatic ecosystems were quantified and mapped using a geostatistical approach, with N deposition, topography, vegetation, geology, and climate as potential explanatory variables. Multiple predictive models were created using various combinations of explanatory variables; this approach allowed us to better quantify uncertainty and more accurately identify the areas most sensitive to atmospherically deposited N. The lowest critical loads estimates and highest exceedances identified within YOSE and SEKI occurred in high-elevation basins with steep slopes, sparse vegetation, and areas of neoglacial till and talus. These results are consistent with previous analyses in the Rocky Mountains, and highlight the sensitivity of alpine ecosystems to atmospheric N deposition.

  11. Pliocene diatoms from the Bryce Canyon Area, Utah

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    habitat. The fragmentary condition of these indicated agitation during sedimentation. The ratio between the planktonic and benthonic diatoms indicated near-shore deposition. The two extinct species (?), @iSurirella craticula@@ (= @iStictodesmis craticula...

  12. The Whittard Canyon - A case study of submarine canyon processes

    Science.gov (United States)

    Amaro, T.; Huvenne, V. A. I.; Allcock, A. L.; Aslam, T.; Davies, J. S.; Danovaro, R.; De Stigter, H. C.; Duineveld, G. C. A.; Gambi, C.; Gooday, A. J.; Gunton, L. M.; Hall, R.; Howell, K. L.; Ingels, J.; Kiriakoulakis, K.; Kershaw, C. E.; Lavaleye, M. S. S.; Robert, K.; Stewart, H.; Van Rooij, D.; White, M.; Wilson, A. M.

    2016-08-01

    Submarine canyons are large geomorphological features that incise continental shelves and slopes around the world. They are often suggested to be biodiversity and biomass hotspots, although there is no consensus about this in the literature. Nevertheless, many canyons do host diverse faunal communities but owing to our lack of understanding of the processes shaping and driving this diversity, appropriate management strategies have yet to be developed. Here, we integrate all the current knowledge of one single system, the Whittard Canyon (Celtic Margin, NE Atlantic), including the latest research on its geology, sedimentology, geomorphology, oceanography, ecology, and biodiversity in order to address this issue. The Whittard Canyon is an active system in terms of sediment transport. The net suspended sediment transport is mainly up-canyon causing sedimentary overflow in some upper canyon areas. Occasionally sediment gravity flow events do occur, some possibly the result of anthropogenic activity. However, the role of these intermittent gravity flows in transferring labile organic matter to the deeper regions of the canyon appears to be limited. More likely, any labile organic matter flushed downslope in this way becomes strongly diluted with bulk material and is therefore of little food value for benthic fauna. Instead, the fresh organic matter found in the Whittard Channel mainly arrives through vertical deposition and lateral transport of phytoplankton blooms that occur in the area during spring and summer. The response of the Whittard Canyon fauna to these processes is different in different groups. Foraminiferal abundances are higher in the upper parts of the canyon and on the slope than in the lower canyon. Meiofaunal abundances in the upper and middle part of the canyon are higher than on adjacent slopes, but lower in the deepest part. Mega- and macrofauna abundances are higher in the canyon compared with the adjacent slope and are higher in the eastern than

  13. 76 FR 23623 - Backcountry Management Plan, Environmental Impact Statement, Grand Canyon National Park, Arizona

    Science.gov (United States)

    2011-04-27

    ...-7945, [email protected] or Rachel Bennett, Environmental Protection Specialist, P.O. Box 129, Grand Canyon, Arizona 86023, 928-638-7326, Rachel[email protected] . SUPPLEMENTARY INFORMATION: If you wish to...

  14. Mineral resources of the Desolation Canyon, Turtle Canyon, and Floy Canyon Wilderness Study Areas, Carbon Emery, and Grand counties, Utah

    International Nuclear Information System (INIS)

    Cashion, W.B.; Kilburn, J.E.; Barton, H.N.; Kelley, K.D.; Kulik, D.M.; McDonnell, J.R.

    1990-09-01

    This paper reports on the Desolation Canyon, Turtle Canyon, and Floy Canyon Wilderness Study Areas which include 242,000 acres, 33,690 acres, and 23,140 acres. Coal deposits underlie all three study areas. Coal zones in the Blackhawk and Nelsen formations have identified bituminous coal resources of 22 million short tons in the Desolation Canyon Study Area, 6.3 million short tons in the Turtle Canyon Study Area, and 45 million short tons in the Floy Canyon Study Area. In-place inferred oil shale resources are estimated to contain 60 million barrels in the northern part of the Desolation Canyon area. Minor occurrences of uranium have been found in the southeastern part of the Desolation Canyon area and in the western part of the Floy Canyon area. Mineral resource potential for the study areas is estimated to be for coal, high for all areas, for oil and gas, high for the northern tract of the Desolation Canyon area and moderate for all other tracts, for bituminous sandstone, high for the northern part of the Desolation Canyon area, and low for all other tracts, for oil shale, low in all areas, for uranium, moderate for the Floy Canyon area and the southeastern part of the Desolation Canyon area and low for the remainder of the areas, for metals other than uranium, bentonite, zeolites, and geothermal energy, low in all areas, and for coal-bed methane unknown in all three areas

  15. A Transformative Undergraduate Field Trip to the Grand Canyon and Death Valley

    Science.gov (United States)

    Smith, J. A.

    2014-12-01

    Seeing the iconic Grand Canyon and Death Valley in person is a transformative experience for most geologists, including nine undergraduate geology students from upstate New York. The students were enrolled in a one-credit course designed around a nine-day spring-break field trip to Grand Canyon National Park (GCNP) and Death Valley National Park (DVNP). We met once a week before the trip to plan day-to-day activities and discuss background geologic information. Students selected a research topic related to our itinerary and wrote a guidebook entry for the topic. Students' entries were combined with papers, maps, and background material to make a guidebook. The printed guidebooks provided students with a "publication" of their work to show to others and refer to in the field. The nine-day field trip started with a flight into Las Vegas, NV, on 3/1/14. We spent three nights camping at the South Rim of the Grand Canyon, one night camping in Valley of Fire State Park (VOFSP, 55 mi N of Las Vegas), and three nights staying at the Shoshone Education and Research Center (SHEAR) east of Death Valley. Highlights of the trip included the hike along the Bright Angel Trail (and fault) to Plateau Point and recognition of the Great Unconformity at GCNP; the White Domes loop hike, camping at the Beehives, and observation of the Muddy Mountain Overthrust in VOFSP; and hikes at Ubehebe Crater, Badwater Salt Flat, and Natural Bridge Canyon in DVNP. Each student presented his/her research topic at a pertinent point in the field trip; students were impressively well-prepared. One requirement of the course was a poster presentation on each student's research topic at our Undergraduate Research Symposium in April. For most of the students, the poster session was the first experience preparing and presenting a poster. In addition, the class gave a joint colloquium presentation to several hundred science majors and a number of science faculty at Saint Rose. Each student spoke for five

  16. Gully monitoring at two locations in the Grand Canyon National Park, Arizona, 1996-2010, with emphasis on documenting effects of the March 2008 high-flow experiment

    Science.gov (United States)

    Schott, Nathan D.; Hazel, Joseph E.; Fairley, Helen C.; Kaplinski, Matt; Parnell, Roderic A.

    2014-01-01

    Many archeological sites in the Grand Canyon are being impacted by gully incision. In March 2008, a high-flow experiment (2008 HFE) was conducted with the intention of redistributing fine sediment (sand, silt, and clay) from the bed of the Colorado River to higher elevations along the channel margin. Deposition of fine sediment in gully mouths has been hypothesized to slow gully erosion rates and lessen impacts to archeological sites. The effects of the 2008 HFE on gullies were evaluated by comparing the topographic changes of three gullies at two study sites before and after the 2008 HFE. Comparison results indicated that sediment was deposited in gully mouths during the 2008 HFE, and that the inundated areas nearest to the river can be extensively altered by mainstream flow during high-flow events. Additionally, the history of gully evolution at the two study sites was examined between 1996 and 2010 and indicated that gullies have been subjected to thalweg incision and gully widening processes over a decadal timescale. Although the small sample size precludes extrapolating the results to other gullies, the findings contribute to the understanding of gully erosion in archeologically significant areas and have implications for future monitoring of gully erosion and evaluating the effectiveness of check dams intended to mitigate that erosion at archaeological sites in the Grand Canyon National Park.

  17. Effects of stock use and backpackers on water quality in wilderness in Sequoia and Kings Canyon National Parks, USA

    Science.gov (United States)

    Clow, David W.; Forrester, Harrison; Miller, Benjamin; Roop, Heidi; Sickman, James O.; Ryu, Hodon; Santo Domingo, Jorge

    2013-01-01

    During 2010-2011, a study was conducted in Sequoia and Kings Canyon National Parks (SEKI) to evaluate the influence of pack animals (stock) and backpackers on water quality in wilderness lakes and streams. The study had three main components: (1) a synoptic survey of water quality in wilderness areas of the parks, (2) paired water-quality sampling above and below several areas with differing types and amounts of visitor use, and (3) intensive monitoring at six sites to document temporal variations in water quality. Data from the synoptic water-quality survey indicated that wilderness lakes and streams are dilute and have low nutrient and Escherichia coli (E. coli) concentrations. The synoptic survey sites were categorized as minimal use, backpacker use, or mixed use (stock and backpackers), depending on the most prevalent type of use upstream from the sampling locations. Sites with mixed use tended to have higher concentrations of most constituents (including E.coli) than those categorized as minimal-use (p≤0.05); concentrations at backpacker-use sites were intermediate. Data from paired-site sampling indicated that E.coli, total coliform, and particulate phosphorus concentrations were greater in streams downstream from mixed-use areas than upstream from those areas (p≤0.05). Paired-site data also indicated few statistically significant differences in nutrient, E. coli, or total coliform concentrations in streams upstream and downstream from backpacker-use areas. The intensive-monitoring data indicated that nutrient and E. coli concentrations normally were low, except during storms, when notable increases in concentrations of E.coli, nutrients, dissolved organic carbon, and turbidity occurred. In summary, results from this study indicate that water quality in SEKI wilderness generally is good, except during storms; and visitor use appears to have a small, but statistically significant influence on stream water quality.

  18. The effects of a low intensity fire on a mixed conifer forest in Bryce Canyon National Park, Utah

    Science.gov (United States)

    Henry V. Bastian

    2001-01-01

    Prescribed fire was used to reduce fuel loading and tree densities. Permanent vegetation and fuel loading plots were randomly established within prescribed burn units. The plots were established in 1995 and were sampled, immediately postburn (within 1 month of the fire), 1 year after the burn, and 2 years after the burn. The prescribed burns were implemented in August...

  19. My Objections to Outcome [Note the Singular] Assessment

    Science.gov (United States)

    Digby, Joan

    2014-01-01

    Rubric means red ochre--red earth--as in Bryce Canyon and Sedona. Red headers were used in medieval manuscripts as section or chapter markers, and you can bet that the Whore of Babylon got herself some fancy rubrics over the years. Through most of its history, the word has been attached to religious texts and liturgy; rubrics were used as…

  20. Diablo Canyon

    International Nuclear Information System (INIS)

    Bindon, F.J.L.

    1986-01-01

    The paper traces the history of Diablo Canyon nuclear power station, California, which took 18 years to reach full-power testing from the planning stage. The major delays during the construction are outlined, as well as the costs of Diablo Canyon. (UK)

  1. The Glen Canyon Dam adaptive management program: progress and immediate challenges

    Science.gov (United States)

    Hamill, John F.; Melis, Theodore S.; Boon, Philip J.; Raven, Paul J.

    2012-01-01

    Adaptive management emerged as an important resource management strategy for major river systems in the United States (US) in the early 1990s. The Glen Canyon Dam Adaptive Management Program (‘the Program’) was formally established in 1997 to fulfill a statutory requirement in the 1992 Grand Canyon Protection Act (GCPA). The GCPA aimed to improve natural resource conditions in the Colorado River corridor in the Glen Canyon National Recreation Area and Grand Canyon National Park, Arizona that were affected by the Glen Canyon dam. The Program achieves this by using science and a variety of stakeholder perspectives to inform decisions about dam operations. Since the Program started the ecosystem is now much better understood and several biological and physical improvements have been achieved. These improvements include: (i) an estimated 50% increase in the adult population of endangered humpback chub (Gila cypha) between 2001 and 2008, following previous decline; (ii) a 90% decrease in non-native rainbow trout (Oncorhynchus mykiss), which are known to compete with and prey on native fish, as a result of removal experiments; and (iii) the widespread reappearance of sandbars in response to an experimental high-flow release of dam water in March 2008.Although substantial progress has been made, the Program faces several immediate challenges. These include: (i) defining specific, measurable objectives and desired future conditions for important natural, cultural and recreational attributes to inform science and management decisions; (ii) implementing structural and operational changes to improve collaboration among stakeholders; (iii) establishing a long-term experimental programme and management plan; and (iv) securing long-term funding for monitoring programmes to assess ecosystem and other responses to management actions. Addressing these challenges and building on recent progress will require strong and consistent leadership from the US Department of the Interior

  2. A sense of place: Ecoregional design at Mesa Verde National Park

    Science.gov (United States)

    Robert G. Bailey

    2012-01-01

    When the National Park Service was established in 1916, the new agency inherited an architectural legacy developed by private interests, particularly the railroads. This legacy included Northern Pacific's Old Faithful Inn in Yellowstone and Santa Fe's El Tovar at the south rim of the Grand Canyon, both built in the Swiss Chalet­Norway Villa tradition. This...

  3. Use of a handheld, battery-operated chemistry analyzer for evaluation of heat-related symptoms in the backcountry of Grand Canyon National Park: a brief report.

    Science.gov (United States)

    Backer, H D; Collins, S

    1999-04-01

    To test the feasibility of using handheld, battery-operated chemical analyzers by EMS personnel in a wilderness environment to aid in the diagnosis and management of heat illness. During the summer of 1996, 3 portable clinical analyzers (i-STAT Corp, Princeton, NJ) were kept at different locations along the main hiking trail into the Grand Canyon. An operational protocol was designed for field use, and Park Service EMS personnel used the instruments at their discretion, primarily to determine serum sodium concentration and identify cases of hyponatremia. Data were collected on all EMS encounters. This study reviews our experience with the instruments. The i-STAT analyzer was used for 64 patients in the backcountry; of these uses, at least 22 were in the field and the remainder in backcountry ranger stations. Eight error messages were recorded in 6 patients. Subsequently, all but 1 had a successful determination. Among patients evacuated for further evaluation and care, serum sodium values were highly consistent with later analysis using standard laboratory equipment. The instrument was used in 31 (48%) of 64 of patients evaluated and released for self-treatment and self-evacuation, and 31 (36%) of 87 of patients evacuated by EMS personnel from the canyon. Nine cases of hyponatremia were confirmed in the field, allowing appropriate intervention. Portable clinical analyzers can reliably be used in a hot wilderness environment. In our application, it allowed identification of exercise-associated hyponatremia, an important cause of serious heat illness during endurance exercise in a hot environment. The results helped make treatment and disposition decisions.

  4. Deciphering Paria and Little Colorado River flood regimes and their significance in multi-objective adaptive management strategies for Colorado River resources in Grand Canyon

    Science.gov (United States)

    Jain, S.; Topping, D. J.; Melis, T. S.

    2014-12-01

    Planning and decision processes in the Glen Canyon Dam Adaptive Management Program (GCDAMP) strive to balance numerous, often competing, objectives, such as, water supply, hydropower generation, low flow maintenance, sandbars, recreational trout angling, endangered native fish, whitewater rafting, and other sociocultural resources of Glen Canyon National Recreation Area and Grand Canyon National Park. In this context, use of monitored and predictive information on warm-season Paria River floods (JUL-OCT, at point-to-regional scales) has been identified as lead information for a new 10-year long controlled flooding experiment (termed the High-Flow Experiment Protocol) intended to determine management options for rebuilding and maintaining sandbars below Glen Canyon Dam; an adaptive strategy that can potentially facilitate improved planning and dam operations. In this work, we focus on a key concern identified by the GCDAMP, related to the timing and volume of warm season tributary sand input from the Paria River into the Colorado River in Grand Canyon National Park. The Little Colorado River is an important secondary source of sand inputs to Grand Canyon, but its lower segment is also critical spawning habitat for the endangered humpback chub. Fish biologists have reported increased abundance of chub juveniles in this key tributary in summers following cool-season flooding (DEC-FEB), but little is known about chub spawning substrates and behavior or the role that flood frequency in this tributary may play in native fish population dynamics in Grand Canyon. Episodic and intraseasonal variations (with links to equatorial and sub-tropical Pacific sea surface temperature variability) in southwest hydroclimatology are investigated to understand the magnitude, timing and spatial scales of warm- and cool-season floods from these two important tributaries of the semi-arid Colorado Plateau. Coupled variations of floods (magnitude and timing) from these rivers are also

  5. Effect of prescribed burning on mortality of resettlement ponderosa pines in Grand Canyon National Park

    Science.gov (United States)

    G. Alan Kaufmann; W. Wallace Covington

    2001-01-01

    Ponderosa pine (Pinus ponderosa) trees established before Euro-American settlement are becoming rare on the landscape. Prescribed fire is the prime tool used to restore ponderosa pine ecosystems, but can cause high mortality in presettlement ponderosa pines. This study uses retrospective techniques to estimate mortality from prescribed burns within Grand Canyon...

  6. Tectonic activity and the evolution of submarine canyons: The Cook Strait Canyon system, New Zealand

    Science.gov (United States)

    Micallef, Aaron; Mountjoy, Joshu; Barnes, Philip; Canals, Miquel; Lastras, Galderic

    2016-04-01

    Submarine canyons are Earth's most dramatic erosional features, comprising steep-walled valleys that originate in the continental shelf and slope. They play a key role in the evolution of continental margins by transferring sediments into deep water settings and are considered important biodiversity hotspots, pathways for nutrients and pollutants, and analogues of hydrocarbon reservoirs. Although comprising only one third of continental margins worldwide, active margins host more than half of global submarine canyons. We still lack of thorough understanding of the coupling between active tectonics and submarine canyon processes, which is necessary to improve the modelling of canyon evolution in active margins and derive tectonic information from canyon morphology. The objectives of this study are to: (i) understand how tectonic activity influences submarine canyon morphology, processes, and evolution in an active margin, and (2) formulate a generalised model of canyon development in response to tectonic forcing based on morphometric parameters. We fulfil these objectives by analysing high resolution geophysical data and imagery from Cook Strait Canyon system, offshore New Zealand. Using these data, we demonstrate that tectonic activity, in the form of major faults and structurally-generated tectonic ridges, leaves a clear topographic signature on submarine canyon location and morphology, in particular their dendritic and sinuous planform shapes, steep and linear longitudinal profiles, and cross-sectional asymmetry and width. We also report breaks/changes in canyon longitudinal slope gradient, relief and slope-area regression models at the intersection with faults. Tectonic activity gives rise to two types of knickpoints in the Cook Strait Canyon. The first type consists of low slope gradient, rounded and diffusive knickpoints forming as a result of short wavelength folds or fault break outs and being restored to an equilibrium profile by upstream erosion and

  7. Geomorphic process fingerprints in submarine canyons

    Science.gov (United States)

    Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.; Twichell, David C.

    2013-01-01

    Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.

  8. Comparative effects of climate on ecosystem nitrogen and soil biogeochemistry in U.S. national parks. FY 2001 Annual Report (Res. Rept. No. 94)

    Science.gov (United States)

    Stottlemyer, R.; Edmonds, R.; Scherbarth, L.; Urbanczyk, K.; Van Miegroet, H.; Zak, J.

    2002-01-01

    In 1998, the USGS Global Change program funded research for a network of Long-Term Reference Ecosystems initially established in national parks and funded by the National Park Service. The network included Noland Divide, Great Smoky Mountains National Park, Tennessee; Pine Canyon, Big Ben National park, Texas; West Twin Creek, Olympic National Park, Washingtona?? Wallace Lake, Isle Royale National Park, Michigan; and the Asik watershed, Noatak National Preserve, Alaska. The watershed ecosystem model was used since this approach permits additional statistical power in detection of trends among variables, and the watershed in increasingly a land unit used in resource management and planning. The ecosystems represent a major fraction of lands administered by the National Park Service, and were chosen generally for the contrasts among sites. For example, tow of the site, Noland and West Twin, are characterized by high precipitation amounts, but Noland receives some of the highest atmospheric nitrogen (N) inputs in North America. In contrast, Pine Canyon and Asik are warm and cold desert sites respectively. The Asik watershed receives treeline) of the boreal biome in the North America while Wallace is at the southern ecotone between boreal and northern hardwoods. The research goal for these sites is to gain a basic understanding of ecosystem structure and function, and the response to global change especially atmospheric inputs and climate.

  9. Use of flux and morphologic sediment budgets for sandbar monitoring on the Colorado River in Marble Canyon, Arizona

    Science.gov (United States)

    Grams, Paul E.; Buscombe, Daniel D.; Topping, David J.; Hazel, Joseph E.; Kaplinski, Matt

    2015-01-01

    The magnitude and pfattern of streamflow and sediment supply of the Colorado River in Grand Canyon (Figure 1) has been affected by the existence and operations of Glen Canyon Dam since filling of Lake Powell Reservoir began in March 1963. In the subsequent 30 years, fine sediment was scoured from the downstream channel (Topping et al., 2000; Grams et al., 2007), resulting in a decline in the number and size of sandbars in the eastern half of Grand Canyon National Park (Wright et al., 2005; Schmidt et al., 2004). The Glen Canyon Dam Adaptive Management Program (GCDAMP) administered by the U.S. Department of Interior oversees efforts to manage the Colorado River ecosystem downstream from Glen Canyon Dam. One of the goals of the GCDAMP is to maintain and increase the number and size of sandbars in this context of a limited sand supply. Management actions to benefit sandbars have included curtailment of daily streamflow fluctuations, which occur for hydropower generation, and implementation of controlled floods, also called high-flow experiments.Studies of controlled floods, defined as intentional releases that exceed the maximum discharge capacity of the Glen Canyon Dam powerplant, implemented between 1996 and 2008, have demonstrated that these events cause increases in sandbar size throughout Marble and Grand Canyons (Hazel et al., 2010; Schmidt and Grams, 2011; Mueller et al., 2014), although the magnitude of response is spatially variable (Hazel et al., 1999; 2010). Controlled floods may build some sandbars at the expense of erosion of sand from other, upstream, sandbars (Schmidt, 1999). To increase the frequency and effectiveness of sandbar building, the U.S. Department of Interior adopted a “high-flow experimental protocol” to implement controlled floods regularly under conditions of enriched sand supply (U.S. Department of Interior, 2012). Because the supply of sand available to build sandbars has been substantially reduced by Glen Canyon Dam (Topping et al

  10. Learning outcomes of in-person and virtual field-based geoscience instruction at Grand Canyon National Park: complementary mixed-methods analyses

    Science.gov (United States)

    Semken, S. C.; Ruberto, T.; Mead, C.; Bruce, G.; Buxner, S.; Anbar, A. D.

    2017-12-01

    Students with limited access to field-based geoscience learning can benefit from immersive, student-centered virtual-reality and augmented-reality field experiences. While no digital modalities currently envisioned can truly supplant field-based learning, they afford students access to geologically illustrative but inaccessible places on Earth and beyond. As leading producers of immersive virtual field trips (iVFTs), we investigate complementary advantages and disadvantages of iVFTs and in-person field trips (ipFTs). Settings for our mixed-methods study were an intro historical-geology class (n = 84) populated mostly by non-majors and an advanced Southwest geology class (n = 39) serving mostly majors. Both represent the diversity of our urban Southwestern research university. For the same credit, students chose either an ipFT to the Trail of Time (ToT) Exhibition at Grand Canyon National Park (control group) or an online Grand Canyon iVFT (experimental group), in the same time interval. Learning outcomes for each group were identically drawn from elements of the ToT and assessed using pre/post concept sketching and inquiry exercises. Student attitudes and cognitive-load factors for both groups were assessed pre/post using the PANAS instrument (Watson et al., 1998) and with affective surveys. Analysis of pre/post concept sketches indicated improved knowledge in both groups and classes, but more so in the iVFT group. PANAS scores from the intro class showed the ipFT students having significantly stronger (p = .004) positive affect immediately prior to the experience than the iVFT students, possibly reflecting their excitement about the trip to come. Post-experience, the two groups were no longer significantly different, possibly due to the fatigue associated with a full-day ipFT. Two lines of evidence suggest that the modalities were comparable in expected effectiveness. First, the information relevant for the concept sketch was specifically covered in both

  11. Flow in bedrock canyons.

    Science.gov (United States)

    Venditti, Jeremy G; Rennie, Colin D; Bomhof, James; Bradley, Ryan W; Little, Malcolm; Church, Michael

    2014-09-25

    Bedrock erosion in rivers sets the pace of landscape evolution, influences the evolution of orogens and determines the size, shape and relief of mountains. A variety of models link fluid flow and sediment transport processes to bedrock incision in canyons. The model components that represent sediment transport processes are increasingly well developed. In contrast, the model components being used to represent fluid flow are largely untested because there are no observations of the flow structure in bedrock canyons. Here we present a 524-kilometre, continuous centreline, acoustic Doppler current profiler survey of the Fraser Canyon in western Canada, which includes 42 individual bedrock canyons. Our observations of three-dimensional flow structure reveal that, as water enters the canyons, a high-velocity core follows the bed surface, causing a velocity inversion (high velocities near the bed and low velocities at the surface). The plunging water then upwells along the canyon walls, resulting in counter-rotating, along-stream coherent flow structures that diverge near the bed. The resulting flow structure promotes deep scour in the bedrock channel floor and undercutting of the canyon walls. This provides a mechanism for channel widening and ensures that the base of the walls is swept clear of the debris that is often deposited there, keeping the walls nearly vertical. These observations reveal that the flow structure in bedrock canyons is more complex than assumed in the models presently used. Fluid flow models that capture the essence of the three-dimensional flow field, using simple phenomenological rules that are computationally tractable, are required to capture the dynamic coupling between flow, bedrock erosion and solid-Earth dynamics.

  12. 2010 Pacific Gas and Electric Diablo Canyon Power Plant (DCPP): Diablo Canyon, CA Central Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Diablo Canyon Power Plant (DCPP) LiDAR and Imagery datasets are comprised of three separate LiDAR surveys: Diablo Canyon (2010), Diablo Canyon (2010), and San...

  13. Stars Above, Earth Below A Guide to Astronomy in the National Parks

    CERN Document Server

    Nordgren, Tyler

    2010-01-01

    In Stars Above, Earth Below, Tyler Nordgren examines a range of astronomical topics and makes the connection between them and the landscapes, processes, and cultures which can be seen and experienced within specific U.S. National Parks. For each park and topic the story unfolds in three steps: what does the reader see for him - or herself? What is the scientific cause or explanation of what is seen? And finally, what is the big picture about ourselves, our world, and our Universe? The author takes us the length and breadth of the U.S., from the coast of Maine to the Yellowstone volcano, from the depths of the Grand Canyon to the heights of the Rocky Mountains, exploring the natural links between the features of the parks and those of our Universe.

  14. Carbon transport in Monterey Submarine Canyon

    Science.gov (United States)

    Barry, J.; Paull, C. K.; Xu, J. P.; Clare, M. A.; Gales, J. A.; Buck, K. R.; Lovera, C.; Gwiazda, R.; Maier, K. L.; McGann, M.; Parsons, D. R.; Simmons, S.; Rosenberger, K. J.; Talling, P. J.

    2017-12-01

    Submarine canyons are important conduits for sediment transport from continental margins to the abyss, but the rate, volume, and time scales of material transport have been measured only rarely. Using moorings with current meters, sediment traps (10 m above bottom) and optical backscatter sensors, we measured near-bottom currents, suspended sediment concentrations, and sediment properties at 1300 m depth in Monterey Canyon and at a non-canyon location on the continental slope at the same depth. Flow and water column backscatter were used to characterize "ambient" conditions when tidal currents dominated the flow field, and occasional "sediment transport events" when anomalously high down-canyon flow with sediment-laden waters arrived at the canyon mooring. The ambient sediment flux measured in sediment traps in Monterey Canyon was 350 times greater than measured at the non-canyon location. Although the organic carbon content of the canyon sediment flux during ambient periods was low (1.8 %C) compared to the slope location (4.9 %C), the ambient carbon transport in the canyon was 130 times greater than at the non-canyon site. Material fluxes during sediment transport events were difficult to measure owing to clogging of sediment traps, but minimal estimates indicate that mass transport during events exceeds ambient sediment fluxes through the canyon by nearly 3 orders of magnitude, while carbon transport is 380 times greater. Estimates of the instantaneous and cumulative flux of sediment and carbon from currents, backscatter, and sediment properties indicated that: 1) net flux is down-canyon, 2) flux is dominated by sediment transport events, and 3) organic carbon flux through 1300 m in Monterey Canyon was ca. 1500 MT C per year. The injection of 1500 MTCy-1 into the deep-sea represents ca. 260 km2 of the sediment C flux measured at the continental slope station (5.8 gCm-2y-1) and is sufficient to support a benthic community carbon demand of 5 gCm-2y-1 over 300 km2.

  15. Formative flow in bedrock canyons

    Science.gov (United States)

    Venditti, J. G.; Kwoll, E.; Rennie, C. D.; Church, M. A.

    2017-12-01

    In alluvial channels, it is widely accepted that river channel configuration is set by a formative flow that represents a balance between the magnitude and frequency of flood flows. The formative flow is often considered to be one that is just capable of filling a river channel to the top of its banks. Flows much above this formative flow are thought to cause substantial sediment transport and rearrange the channel morphology to accommodate the larger flow. This idea has recently been extended to semi-alluvial channels where it has been shown that even with bedrock exposed, the flows rarely exceed that required to entrain the local sediment cover. What constitutes a formative flow in a bedrock canyon is not clear. By definition, canyons have rock walls and are typically incised vertically, removing the possibility of the walls being overtopped, as can occur in an alluvial channel at high flows. Canyons are laterally constrained, have deep scour pools and often have width to maximum depth ratios approaching 1, an order of magnitude lower than alluvial channels. In many canyons, there are a sequence of irregularly spaced scour pools. The bed may have intermittent or seasonal sediment cover, but during flood flows the sediment bed is entrained leaving a bare bedrock channel. It has been suggested that canyons cut into weak, well-jointed rock may adjust their morphology to the threshold for block plucking because the rock bed is labile during exceptionally large magnitude flows. However, this hypothesis does not apply to canyons cut into massive crystalline rock where abrasion is the dominant erosion process. Here, we argue that bedrock canyon morphology is adjusted to a characteristic flow structure developed in bedrock canyons. We show that the deeply scoured canyon floor is adjusted to a velocity inversion that is present at low flows, but gets stronger at high flows. The effect is to increase boundary shear stresses along the scour pool that forms in constricted

  16. Let's Bet on Sediments! Hudson Canyon Cruise--Grades 9-12. Focus: Sediments of Hudson Canyon.

    Science.gov (United States)

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    These activities are designed to teach about the sediments of Hudson Canyon. Students investigate and analyze the patterns of sedimentation in the Hudson Canyon, observe how heavier particles sink faster than finer particles, and learn that submarine landslides are avalanches of sediment in deep ocean canyons. The activity provides learning…

  17. Age of Barrier Canyon-style rock art constrained by cross-cutting relations and luminescence dating techniques

    DEFF Research Database (Denmark)

    Pederson, Joel L.; Chapot, Melissa S.; Simms, Steven R.

    2014-01-01

    Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses......, the type section of BCS art in Canyon-lands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research dating both a rockfall that removed some figures and the rock's exposure...... duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A. D. similar to 1...

  18. USGS Workshop on Scientific Aspects of a Long-Term Experimental Plan for Glen Canyon Dam, April 10-11, 2007, Flagstaff, Arizona

    Science.gov (United States)

    ,

    2008-01-01

    Executive Summary Glen Canyon Dam is located in the lower reaches of Glen Canyon National Recreation Area on the Colorado River, approximately 15 miles upriver from Grand Canyon National Park (fig. 1). In 1992, Congress passed and the President signed into law the Grand Canyon Protection Act (GCPA; title XVIII, sec. 1801?1809, of Public Law 102-575), which seeks ?to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established.? The Glen Canyon Dam Adaptive Management Program (GCDAMP) was implemented as a result of the 1996 Record of Decision on the Operation of Glen Canyon Dam Final Environmental Impact Statement to ensure that the primary mandate of the GCPA is met through advances in information and resources management (U.S. Department of the Interior, 1995). On November 3, 2006, the Bureau of Reclamation (Reclamation) announced it would develop a long-term experimental plan environmental impact statement (LTEP EIS) for operational activities at Glen Canyon Dam and other management actions on the Colorado River. The purpose of the long-term experimental plan is twofold: (1) to increase the scientific understanding of the ecosystem and (2) to improve and protect important downstream resources. The proposed plan would implement a structured, longterm program of experimentation to include dam operations, potential modifications to Glen Canyon Dam intake structures, and other management actions such as removal of nonnative fish species. The development of the long-term experimental plan continues efforts begun by the GCDAMP to protect resources downstream of Glen Canyon Dam, including Grand Canyon, through adaptive management and scientific experimentation. The LTEP EIS will rely on the extensive scientific studies that have been undertaken as part of the adaptive management program by the U.S. Geological Survey?s (USGS) Grand Canyon Monitoring and Research Center (GCMRC

  19. Wintertime Boundary Layer Structure in the Grand Canyon.

    Science.gov (United States)

    Whiteman, C. David; Zhong, Shiyuan; Bian, Xindi

    1999-08-01

    Wintertime temperature profiles in the Grand Canyon exhibit a neutral to isothermal stratification during both daytime and nighttime, with only rare instances of actual temperature inversions. The canyon warms during daytime and cools during nighttime more or less uniformly through the canyon's entire depth. This weak stability and temperature structure evolution differ from other Rocky Mountain valleys, which develop strong nocturnal inversions and exhibit convective and stable boundary layers that grow upward from the valley floor. Mechanisms that may be responsible for the different behavior of the Grand Canyon are discussed, including the possibility that the canyon atmosphere is frequently mixed to near-neutral stratification when cold air drains into the top of the canyon from the nearby snow-covered Kaibab Plateau. Another feature of canyon temperature profiles is the sharp inversions that often form near the canyon rims. These are generally produced when warm air is advected over the canyon in advance of passing synoptic-scale ridges.Wintertime winds in the main canyon are not classical diurnal along-valley wind systems. Rather, they are driven along the canyon axis by the horizontal synoptic-scale pressure gradient that is superimposed along the canyon's axis by passing synoptic-scale weather disturbances. They may thus bring winds into the canyon from either end at any time of day.The implications of the observed canyon boundary layer structure for air pollution dispersion are discussed.

  20. Contemporary sediment-transport processes in submarine canyons.

    Science.gov (United States)

    Puig, Pere; Palanques, Albert; Martín, Jacobo

    2014-01-01

    Submarine canyons are morphological incisions into continental margins that act as major conduits of sediment from shallow- to deep-sea regions. However, the exact mechanisms involved in sediment transfer within submarine canyons are still a subject of investigation. Several studies have provided direct information about contemporary sedimentary processes in submarine canyons that suggests different modes of transport and various triggering mechanisms. Storm-induced turbidity currents and enhanced off-shelf advection, hyperpycnal flows and failures of recently deposited fluvial sediments, dense shelf-water cascading, canyon-flank failures, and trawling-induced resuspension largely dominate present-day sediment transfer through canyons. Additionally, internal waves periodically resuspend ephemeral deposits within canyons and contribute to dispersing particles or retaining and accumulating them in specific regions. These transport processes commonly deposit sediments in the upper- and middle-canyon reaches for decades or centuries before being completely or partially flushed farther down-canyon by large sediment failures.

  1. Environmenal analysis of the Bayo Canyon (TA-10) Site, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Hansen, W.R.

    1982-05-01

    The radiological survey of the old TA-10 site in Bayo Canyon found low levels of surface contamination in the vicinity of the firing sites and subsurface contamination in the old waste disposal area. The three alternatives proposed for the site are: (1) to take no action; (2) to restrict usage of the area of subsurface contamination to activities that cause no subsurface disturbance (minimal action); and (3) to remove the subsurface conamination to levels below the working criteria. Dose calculations indicate that doses from surface contamination for recreational users of the canyon, permanent residents, and construction workers and doses for workers involved in excavation of contaminated soil under the clean up alternative are only small percentages of applicable guidelines. No environmental impacts are associated with either the no-action or minimal action alternatives. The impact associated with the cleanup alternative is small, especially considering that the area already has been affected by the original TA-10 decommissioning action, but nevertheless, the preferred alternative is the minimal action alternative, where 0.6 hectare of land is restricted to surface activities. This leaves the rest of the canyon available for development with up to 400 homes. The restricted area can be used for a park, tennis courts, etc., and the /sup 90/Sr activity will decay to levels permitting unrestricted usage in about 160 y.

  2. Environmenal analysis of the Bayo Canyon (TA-10) Site, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Hansen, W.R.

    1982-05-01

    The radiological survey of the old TA-10 site in Bayo Canyon found low levels of surface contamination in the vicinity of the firing sites and subsurface contamination in the old waste disposal area. The three alternatives proposed for the site are: (1) to take no action; (2) to restrict usage of the area of subsurface contamination to activities that cause no subsurface disturbance (minimal action); and (3) to remove the subsurface conamination to levels below the working criteria. Dose calculations indicate that doses from surface contamination for recreational users of the canyon, permanent residents, and construction workers and doses for workers involved in excavation of contaminated soil under the clean up alternative are only small percentages of applicable guidelines. No environmental impacts are associated with either the no-action or minimal action alternatives. The impact associated with the cleanup alternative is small, especially considering that the area already has been affected by the original TA-10 decommissioning action, but nevertheless, the preferred alternative is the minimal action alternative, where 0.6 hectare of land is restricted to surface activities. This leaves the rest of the canyon available for development with up to 400 homes. The restricted area can be used for a park, tennis courts, etc., and the 90 Sr activity will decay to levels permitting unrestricted usage in about 160 y

  3. Street canyon aerosol pollutant transport measurements.

    Science.gov (United States)

    Longley, I D; Gallagher, M W; Dorsey, J R; Flynn, M; Bower, K N; Allan, J D

    2004-12-01

    Current understanding of dispersion in street canyons is largely derived from relatively simple dispersion models. Such models are increasingly used in planning and regulation capacities but are based upon a limited understanding of the transport of substances within a real canyon. In recent years, some efforts have been made to numerically model localised flow in idealised canyons (e.g., J. Appl. Meteorol. 38 (1999) 1576-89) and stepped canyons (Assimakopoulos V. Numerical modelling of dispersion of atmospheric pollution in and above urban canopies. PhD thesis, Imperial College, London, 2001) but field studies in real canyons are rare. To further such an understanding, a measurement campaign has been conducted in an asymmetric street canyon with busy one-way traffic in central Manchester in northern England. The eddy correlation method was used to determine fluxes of size-segregated accumulation mode aerosol. Measurements of aerosol at a static location were made concurrently with measurements on a platform lift giving vertical profiles. Size-segregated measurements of ultrafine and coarse particle concentrations were also made simultaneously at various heights. In addition, a small mobile system was used to make measurements of turbulence at various pavement locations within the canyon. From this data, various features of turbulent transport and dispersion in the canyon will be presented. The concentration and the ventilation fluxes of vehicle-related aerosol pollutants from the canyon will be related to controlling factors. The results will also be compared with citywide ventilation data from a separate measurement campaign conducted above the urban canopy.

  4. Geohydrology of White Rock Canyon of the Rio Grande from Otowi to Frijoles Canyon

    International Nuclear Information System (INIS)

    Purtymun, W.D.; Peters, R.J.; Owens, J.W.

    1980-12-01

    Twenty-seven springs discharge from the Totavi Lentil and Tesuque Formation in White Rock Canyon. Water generally acquires its chemical characteristics from rock units that comprise the spring aquifer. Twenty-two of the springs are separated into three groups of similar aquifer-related chemical quality. The five remaining springs make up a fourth group with a chemical quality that differs due to localized conditions in the aquifer. Localized conditions may be related to recharge or discharge in or near basalt intrusion or through faults. Streams from Pajarito, Ancho, and Frijoles Canyons discharge into the Rio Grande in White Rock Canyon. The base flow in the streams is from springs. Sanitary effluent in Mortandad Canyon from the treatment plant at White Rock also reaches the Rio Grande

  5. 78 FR 48670 - Boulder Canyon Project

    Science.gov (United States)

    2013-08-09

    ... DEPARTMENT OF ENERGY Western Area Power Administration Boulder Canyon Project AGENCY: Western Area... Canyon Project (BCP) electric service provided by the Western Area Power Administration (Western). The... INFORMATION: Hoover Dam, authorized by the Boulder Canyon Project Act (45 Stat. 1057, December 21, 1928), sits...

  6. 77 FR 48151 - Boulder Canyon Project

    Science.gov (United States)

    2012-08-13

    ... DEPARTMENT OF ENERGY Western Area Power Administration Boulder Canyon Project AGENCY: Western Area... Canyon Project (BCP) electric service provided by the Western Area Power Administration (Western). The... INFORMATION: Hoover Dam, authorized by the Boulder Canyon Project Act (45 Stat. 1057, December 21, 1928), sits...

  7. Marble Canyon 10 x 20 NTMS area Arizona: data report

    International Nuclear Information System (INIS)

    Heffner, J.D.

    1980-07-01

    Results of ground water and stream/surface sediment reconnaissance (HSSR) in the National Topographic Map Series (NTMS) Marble Canyon 1 0 x 2 0 quadrangle are presented. The target sampling density for all media collected was one site per 12 square kilometers. This resulted in 884 sediment samples being collected; however, dry conditions and sparse population resulted in the collection of only 2 ground water samples. Grand Canyon National Park, Glen Canyon National Recreation Area, and much Indian tribal land in the southern half of the quadrangle were not sampled. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements for sediment samples are presented in tables and maps. Statistical summaries of data and a brief description of results are given. A generalized geologic map and a summary of the geology of the area are included. Data from ground water include: water chemistry measurements (pH, conductivity, and alkalinity); physical measurements (water temperature, and scintillometer readings); and elemental analyses (U, Al, Br, Cl, Dy, F, He, Mg, Mn, Na, and V). Data from sediment sites include: water chemistry measurements (where available) for pH, conductivity, and alkalinity; and elemental analyses(U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Histograms, cumulative frequency, and areal distribution plots for most elements; Log U/Th, Log U/Hf, and Log U/(Th + Hf) ratios; and scintillometer readings are included

  8. Durable terrestrial bedrock predicts submarine canyon formation

    Science.gov (United States)

    Smith, Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

    2017-01-01

    Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

  9. Visitor Assessment of the Mandatory Alternative Transportation System at Zion National Park

    Science.gov (United States)

    Mace, Britton L.; Marquit, Joshua D.; Bates, Scott C.

    2013-11-01

    Transportation infrastructure in national parks has historically been designed for the automobile. With more vehicles in the parks, visitors found themselves in circumstances more reminiscent of a city than a park. Traffic jams, overcrowding, illegal parking, horn honking, and idling vehicles became common, creating stress and contributing to air and noise pollution, the very things visitors were hoping to get away from. Park managers began searching for alternatives, including shuttle systems. Many national parks have implemented optional shuttle systems, but relatively few have completely closed roads to vehicles, transporting visitors on mandatory shuttles. Zion National Park instituted a mandatory shuttle system in May 2000 to relieve crowding and congestion in the main canyon and to protect natural resources. Taking a longitudinal approach, attributes of the shuttle (e.g., crowding, accessibility, freedom, efficiency, preference, and success) were assessed with experiential park factors (e.g., scenic beauty, naturalness, solitude, tranquility, air quality, and soundscape) in 2000, 2003, and 2010 by surveying shuttle-riding park visitors. While visitors initially reported a few reservations about the shuttle system, by 2003, the majority rated the system successful. Ratings of all shuttle-related variables, except crowding, improved over the decade. Improvements were greatest for freedom, accessibility, and efficiency. Multiple regression found overall shuttle success to be mediated by preference, freedom, accessibility, efficiency, and comfort. Experiential variables assessing park conditions followed a similar pattern, with improved ratings as the decade progressed. Results provide important insights into the visitor experience with mandatory alternative shuttle systems in national parks.

  10. Canyons off northwest Puerto Rico

    International Nuclear Information System (INIS)

    Gardner, W.D.; Glover, L.K.; Hollister, C.D.

    1980-01-01

    The Nuclear-Research Submarine NR-1 was used to study morphoplogy, sediment, and sediment-water interactions off the northwest coast of Puerto Rico. New detailed bathymetry from the surface-support ship, USS Portland, shows several submarine canyons in the area, some of them unreported previously. The north coast canyons, Arecibo, Tiberones and Quebradillas, are primarily erosional features although no recent turbidity-current evidence is seen. The canyons are presently filling with river-transported sediments. (orig./ME)

  11. Comment: On Science and Pseudo-Science in National Parks

    Science.gov (United States)

    Asten, Michael W.

    2004-01-01

    The article by Wilfred Elders, ``Different Views of the Grand Canyon,'' (Eos, 23 September 2003) is a valuable reminder of the continuing need for geoscientists to argue geological facts with groups who confuse belief with scientific study. However, his good work is somewhat diminished by the suggestion at the end of his article that a book published by creationists should not be sold within a National Park. There is a whiff of censorship in this proposal that could have consequences beyond what he may intend. I have noted in parks in the United States, and probably more obviously in parks in my own country of Australia, that much literature is available on the origins of the park's geology, flora, and fauna, as presented by the lore of indigenous peoples who claim historical links with the area. Any attempt to censor literature published by creationists would logically result in censorship of material from traditional custodians of the land as well, since their material is equally dubious in terms of its scientific foundation as seen by our post-Darwinian science. Such an attempt at censorship would be both unhelpful and unnecessary for the advancement of our profession in the eyes of the public.

  12. Environmental assessment: Davis Canyon site, Utah

    International Nuclear Information System (INIS)

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has fond that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization. 181 figs., 175 tabs

  13. Environmental assessment: Davis Canyon site, Utah

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high- level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has found that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of the five sites suitable for characterization.

  14. Environmental assessment: Davis Canyon site, Utah

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has fond that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization. 181 figs., 175 tabs.

  15. Environmental assessment: Davis Canyon site, Utah

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considering for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has found that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization.

  16. Environmental assessment: Davis Canyon site, Utah

    International Nuclear Information System (INIS)

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considering for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has found that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization

  17. Environmental assessment: Davis Canyon site, Utah

    International Nuclear Information System (INIS)

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high- level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EA. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site -- the Lavender Canyon site. Although the Lavender Canyon site is suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. Furthermore, the DOE has found that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of the five sites suitable for characterization

  18. Mercury and selenium accumulation in the Colorado River food web, Grand Canyon, USA

    Science.gov (United States)

    Walters, David M.; E.J. Rosi-Marshall,; Kennedy, Theodore A.; W.F. Cross,; C.V. Baxter,

    2015-01-01

    Mercury (Hg) and selenium (Se) biomagnify in aquatic food webs and are toxic to fish and wildlife. The authors measured Hg and Se in organic matter, invertebrates, and fishes in the Colorado River food web at sites spanning 387 river km downstream of Glen Canyon Dam (AZ, USA). Concentrations were relatively high among sites compared with other large rivers (mean wet wt for 6 fishes was 0.17–1.59 μg g–1 Hg and 1.35–2.65 μg g–1 Se), but consistent longitudinal patterns in Hg or Se concentrations relative to the dam were lacking. Mercury increased (slope = 0.147) with δ15N, a metric of trophic position, indicating biomagnification similar to that observed in other freshwater systems. Organisms regularly exceeded exposure risk thresholds for wildlife and humans (6–100% and 56–100% of samples for Hg and Se, respectfully, among risk thresholds). In the Colorado River, Grand Canyon, Hg and Se concentrations pose exposure risks for fish, wildlife, and humans, and the findings of the present study add to a growing body of evidence showing that remote ecosystems are vulnerable to long-range transport and subsequent bioaccumulation of contaminants. Management of exposure risks in Grand Canyon will remain a challenge, as sources and transport mechanisms of Hg and Se extend far beyond park boundaries. Environ Toxicol Chem2015;9999:1–10

  19. Hydrogeology of Middle Canyon, Oquirrh Mountains, Tooele County, Utah

    Science.gov (United States)

    Gates, Joseph Spencer

    1963-01-01

    Geology and climate are the principal influences affecting the hydrology of Middle Canyon, Tooele County, Utah. Reconnaissance in the canyon indicated that the geologic influences on the hydrology may be localized; water may be leaking through fault and fracture zones or joints in sandstone and through solution openings in limestone of the Oquirrh formation of Pennsylvanian and Permian age. Surficial deposits of Quaternary age serve as the main storage material for ground water in the canyon and transmit water from the upper canyon to springs and drains at the canyon mouth. The upper canyon is a more important storage area than the lower canyon because the surficial deposits are thicker, and any zones of leakage in the underlying bedrock of the upper canyon probably would result in greater leakage than would similar outlets in the lower canyon.The total annual discharge from Middle Canyon, per unit of precipitation, decreased between 1910 and 1939. Similar decreases occurred in Parleys Canyon in the nearby Wasatch Range and in other drainage basins in Utah, and it is likely that most of the decrease in discharge from Middle Canyon and other canyons in Utah is due to a change in climate.Chemical analyses of water showed that the high content of sulfate and other constituents in the water from the Utah Metals tunnel, which drains into Middle Canyon, does not have a significant effect on water quality at the canyon mouth. This suggests that much of the tunnel water is lost from the channel by leakage, probably in the upper canyon, during the dry part of the year.Comparison of the 150 acre-feet of water per square mile of drainage area discharged by Middle Canyon in 1947 with the 623 and 543 acre-feet per square mile discharged in 1948 by City Creek and Mill Creek Canyons, two comparable drainage basins in the nearby Wasatch Range, also suggests that there is leakage in Middle Canyon.A hydrologic budget of the drainage basin results in an estimate that about 3,000 acre

  20. Late Holocene earthquake history of the Brigham City segment of the Wasatch fault zone at the Hansen Canyon, Kotter Canyon, and Pearsons Canyon trench sites, Box Elder County, Utah

    Science.gov (United States)

    DuRoss, Christopher B.; Personius, Stephen F.; Crone, Anthony J.; McDonald, Greg N.; Briggs, Richard W.

    2012-01-01

    Of the five central segments of the Wasatch fault zone (WFZ) having evidence of recurrent Holocene surface-faulting earthquakes, the Brigham City segment (BCS) has the longest elapsed time since its most recent surface-faulting event (~2.1 kyr) compared to its mean recurrence time between events (~1.3 kyr). Thus, the BCS has the highest time-dependent earthquake probability of the central WFZ. We excavated trenches at three sites––the Kotter Canyon and Hansen Canyon sites on the north-central BCS and Pearsons Canyon site on the southern BCS––to determine whether a surface-faulting earthquake younger than 2.1 ka occurred on the BCS. Paleoseismic data for Hansen Canyon and Kotter Canyon confirm that the youngest earthquake on the north-central BCS occurred before 2 ka, consistent with previous north-central BCS investigations at Bowden Canyon and Box Elder Canyon. At Hansen Canyon, the most recent earthquake is constrained to 2.1–4.2 ka and had 0.6–2.5 m of vertical displacement. At Kotter Canyon, we found evidence for two events at 2.5 ± 0.3 ka and 3.5 ± 0.3 ka, with an average displacement per event of 1.9–2.3 m. Paleoseismic data from Pearsons Canyon, on the previously unstudied southern BCS, indicate that a post-2 ka earthquake ruptured this part of the segment. The Pearsons Canyon earthquake occurred at 1.2 ± 0.04 ka and had 0.1–0.8 m of vertical displacement, consistent with our observation of continuous, youthful scarps on the southern 9 km of the BCS having 1–2 m of late Holocene(?) surface offset. The 1.2-ka earthquake on the southern BCS likely represents rupture across the Weber–Brigham City segment boundary from the penultimate Weber-segment earthquake at about 1.1 ka. The Pearsons Canyon data result in a revised length of the BCS that has not ruptured since 2 ka (with time-dependent probability implications), and provide compelling evidence of at least one segment-boundary failure and multi-segment rupture on the central WFZ. Our

  1. Remote sensing of tamarisk beetle (Diorhabda carinulata) impacts along 412 km of the Colorado River in the Grand Canyon, Arizona, USA

    Science.gov (United States)

    Bedford, Ashton; Sankey, Temuulen T.; Sankey, Joel B.; Durning, Laura E.C.; Ralston, Barbara

    2018-01-01

    Tamarisk (Tamarix spp.) is an invasive plant species that is rapidly expanding along arid and semi-arid rivers in the western United States. A biocontrol agent, tamarisk beetle (Diorhabda carinulata), was released in 2001 in California, Colorado, Utah, and Texas. In 2009, the tamarisk beetle was found further south than anticipated in the Colorado River ecosystem within the Grand Canyon National Park and Glen Canyon National Recreation Area. Our objectives were to classify tamarisk stands along 412 km of the Colorado River from the Glen Canyon Dam through the Grand Canyon National Park using 2009 aerial, high spatial resolution multispectral imagery, and then quantify tamarisk beetle impacts by comparing the pre-beetle images from 2009 with 2013 post-beetle images. We classified tamarisk presence in 2009 using the Mahalanobis Distance method with a total of 2500 training samples, and assessed the classification accuracy with an independent set of 7858 samples across 49 image quads. A total of 214 ha of tamarisk were detected in 2009 along the Colorado River, where each image quad, on average, included an 8.4 km segment of the river. Tamarisk detection accuracies varied across the 49 image quads, but the combined overall accuracy across the entire study region was 74%. Using the Normalized Difference Vegetation Index (NDVI) from 2009 and 2013 with a region-specific ratio of >1.5 decline between the two image dates (2009NDVI/2013NDVI), we detected tamarisk defoliation due to beetle herbivory. The total beetle-impacted tamarisk area was 32 ha across the study region, where tamarisk defoliation ranged 1–86% at the local levels. Our tamarisk classification can aid long-term efforts to monitor the spread and impact of the beetle along the river and the eventual mortality of tamarisk due to beetle impacts. Identifying areas of tamarisk defoliation is a useful ecological indicator for managers to plan restoration and tamarisk removal efforts.

  2. The Black Canyon of the Gunnison: Today and Yesterday

    Science.gov (United States)

    Hansen, Wallace R.

    1965-01-01

    Since the early visit of Captain John William Gunnison in the middle of the last century, the Black Canyon of the Gunnison has stirred mixed apprehension and wonder in the hearts of its viewers. It ranks high among the more awesome gorges of North America. Many great western canyons are as well remembered for their brightly colored walls as for their airy depths. Not so the Black Canyon. Though it is assuredly not black, the dark-gray tones of its walls and the hazy shadows of its gloomy depths join together to make its name well deserved. Its name conveys an impression, not a picture. After the first emotional impact of the canyon, the same questions come to the minds of most reflective viewers and in about the following order: How deep is the Black Canyon, how wide, how does it compare with other canyons, what are the rocks, how did it form, and how long did it take? Several western canyons exceed the Black Canyon in overall size. Some are longer; some are deeper; some are narrower; and a few have walls as steep. But no other canyon in North American combines the depth, narrowness, sheerness, and somber countenance of the Black Canyon. In many places the Black Canyon is as deep as it is wide. Between The Narrows and Chasm View in the Black Canyon of the Gunnison National Monument (fig. 15) it is much deeper than wide. Average depth in the monument is about 2,000 feet, ranging from a maximum of about 2,700 feet, north of Warner Point (which also is the greatest depth anywhere in the canyon), to a minimum of about 1,750 feet at The Narrows. The stretch of canyon between Pulpit Rock and Chasm View, including The Narrows, though the shallowest in the monument, is also the narrowest, has some of the steepest walls, and is, therefore, among the most impressive segments of the canyon (fig. 3). Profiles of several well-known western canyons are shown in figure 1. Deepest of these by far is Hells Canyon of the Snake, on the Idaho-Oregon border. Clearly, it dwarfs the

  3. The impact of an urban park on air pollution and noise levels in the Mediterranean city of Tel-Aviv, Israel.

    Science.gov (United States)

    Cohen, Pninit; Potchter, Oded; Schnell, Izhak

    2014-12-01

    This study examines the influence of urban parks on air quality and noise in the city of Tel-Aviv, Israel, by investigation of an urban park, an urban square and a street canyon. Simultaneous monitoring of several air pollutants and noise levels were conducted. The results showed that urban parks can reduce NOx, CO and PM10 and increase O3 concentrations and that park's mitigation effect is greater at higher NOx and PM10 levels. During extreme events, mean values of 413 ppb NOx and 80 μG/m3 PM10 were measured in the street while mean values of 89 ppb NOx and 24 μG/m3 PM10 were measured in the park. Whereas summer highest O3 values of 84 ppb were measured in the street, 94 ppb were measured in the park. The benefit of the urban park in reducing NOx and PM10 concentrations is more significant than the disadvantage of increased O3 levels. Furthermore, urban parks can reduce noise by ∼5 dB(A). Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Separations canyon decontamination facilities

    International Nuclear Information System (INIS)

    Hershey, J.H.

    1975-01-01

    Highly radioactive process equipment is decontaminated at the Savannah River Plant in specially equipped areas of the separations canyon building so that direct mechanical repairs or alterations can be made. Using these facilities it is possible to decontaminate and repair equipment such as 10- x 11-ft storage tanks, 8- x 8-ft batch evaporator pots and columns, 40-in. Bird centrifuges, canyon pumps and agitators, and various canyon piping systems or ''jumpers.'' For example, centrifuge or evaporator pots can be decontaminated and rebuilt for about 60 percent of the 1974 replacement cost. The combined facilities can decontaminate and repair 6 to 10 pieces of major equipment per year. Decontamination time varies with type of equipment and radioactivity levels encountered

  5. Separations canyon decontamination facilities

    International Nuclear Information System (INIS)

    Hershey, J.H.

    1975-05-01

    Highly radioactive process equipment is decontaminated at the Savannah River Plant in specially equipped areas of the separations canyon buildings so that direct mechanical repairs or alterations can be made. Using these facilities it is possible to decontaminate and repair equipment such as 10- x 11-ft storage tanks, 8- x 8-ft batch evaporator pots and columns, 40-in. Bird centrifuges, canyon pumps and agitators, and various canyon piping systems or ''jumpers.'' For example, centrifuge or evaporator pots can be decontaminated and rebuilt for about 60 percent of the 1974 replacement cost. The combined facilities can decontaminate and repair 6 to 10 pieces of major equipment per year. Decontamination time varies with type of equipment and radioactivity levels encountered. (U.S.)

  6. Flow dynamics around downwelling submarine canyons

    Directory of Open Access Journals (Sweden)

    J. M. Spurgin

    2014-10-01

    Full Text Available Flow dynamics around a downwelling submarine canyon were analysed with the Massachusetts Institute of Technology general circulation model. Blanes Canyon (northwestern Mediterranean was used for topographic and initial forcing conditions. Fourteen scenarios were modelled with varying forcing conditions. Rossby and Burger numbers were used to determine the significance of Coriolis acceleration and stratification (respectively and their impacts on flow dynamics. A new non-dimensional parameter (χ was introduced to determine the significance of vertical variations in stratification. Some simulations do see brief periods of upwards displacement of water during the 10-day model period; however, the presence of the submarine canyon is found to enhance downwards advection of density in all model scenarios. High Burger numbers lead to negative vorticity and a trapped anticyclonic eddy within the canyon, as well as an increased density anomaly. Low Burger numbers lead to positive vorticity, cyclonic circulation, and weaker density anomalies. Vertical variations in stratification affect zonal jet placement. Under the same forcing conditions, the zonal jet is pushed offshore in more uniformly stratified domains. The offshore jet location generates upwards density advection away from the canyon, while onshore jets generate downwards density advection everywhere within the model domain. Increasing Rossby values across the canyon axis, as well as decreasing Burger values, increase negative vertical flux at shelf break depth (150 m. Increasing Rossby numbers lead to stronger downwards advection of a passive tracer (nitrate, as well as stronger vorticity within the canyon. Results from previous studies are explained within this new dynamic framework.

  7. 75 FR 33576 - Animal Traceability; Public Meetings

    Science.gov (United States)

    2010-06-14

    ... Bryce Ballroom, Sheraton Salt Lake City Hotel, 150 West 500 South, Salt Lake City, UT 84101. The public... commitment to partnering with States, Tribal Nations, and industry to address many of the details of the... City Hotel, there will be complimentary parking, as well as shuttle service to and from Salt Lake...

  8. Application of a new genetic classification and semi-automated geomorphic mapping approach in the Perth submarine canyon, Australia

    Science.gov (United States)

    Picard, K.; Nanson, R.; Huang, Z.; Nichol, S.; McCulloch, M.

    2017-12-01

    The acquisition of high resolution marine geophysical data has intensified in recent years (e.g. multibeam echo-sounding, sub-bottom profiling). This progress provides the opportunity to classify and map the seafloor in greater detail, using new methods that preserve the links between processes and morphology. Geoscience Australia has developed a new genetic classification approach, nested within the Harris et al (2014) global seafloor mapping framework. The approach divides parent units into sub-features based on established classification schemes and feature descriptors defined by Bradwell et al. (2016: http://nora.nerc.ac.uk/), the International Hydrographic Organization (https://www.iho.int) and the Coastal Marine and Ecological Classification Standard (https://www.cmecscatalog.org). Owing to the ecological significance of submarine canyon systems in particular, much recent attention has focused on defining their variation in form and process, whereby they can be classified using a range of topographic metrics, fluvial dis/connection and shelf-incising status. The Perth Canyon is incised into the continental slope and shelf of southwest Australia, covering an area of >1500 km2 and extending from 4700 m water depth to the shelf break in 170 m. The canyon sits within a Marine Protected Area, incorporating a Marine National Park and Habitat Protection Zone in recognition of its benthic and pelagic biodiversity values. However, detailed information of the spatial patterns of the seabed habitats that influence this biodiversity is lacking. Here we use 20 m resolution bathymetry and acoustic backscatter data acquired in 2015 by the Schmidt Ocean Institute plus sub-bottom datasets and sediment samples collected Geoscience Australia in 2005 to apply the new geomorphic classification system to the Perth Canyon. This presentation will show the results of the geomorphic feature mapping of the canyon and its application to better defining potential benthic habitats.

  9. 236-Z canyon utilization study

    International Nuclear Information System (INIS)

    Dixon, D.R.

    1977-01-01

    The 236-Z canyon contains equipment for repurification of plutonium and recovery of plutonium from scrap material. To meet production requirements of Fast Flux Test Facility/Clinch River Breeder Reactor oxide with the existing plant, several new pieces of equipment will be needed in the future. More storage space and a better accountability system are needed to support this increased production. The available canyon space needs to be utilized to its fullest in order to accommodate the new equipment. The purpose of this document is to identify the new pieces of equipment, show how they fit into the flowsheet, and locate them in the canyon

  10. Ventilation Processes in a Three-Dimensional Street Canyon

    Science.gov (United States)

    Nosek, Štěpán; Kukačka, Libor; Kellnerová, Radka; Jurčáková, Klára; Jaňour, Zbyněk

    2016-05-01

    The ventilation processes in three different street canyons of variable roof geometry were investigated in a wind tunnel using a ground-level line source. All three street canyons were part of an urban-type array formed by courtyard-type buildings with pitched roofs. A constant roof height was used in the first case, while a variable roof height along the leeward or windward walls was simulated in the two other cases. All street-canyon models were exposed to a neutrally stratified flow with two approaching wind directions, perpendicular and oblique. The complexity of the flow and dispersion within the canyons of variable roof height was demonstrated for both wind directions. The relative pollutant removals and spatially-averaged concentrations within the canyons revealed that the model with constant roof height has higher re-emissions than models with variable roof heights. The nomenclature for the ventilation processes according to quadrant analysis of the pollutant flux was introduced. The venting of polluted air (positive fluctuations of both concentration and velocity) from the canyon increased when the wind direction changed from perpendicular to oblique, irrespective of the studied canyon model. Strong correlations (>0.5) between coherent structures and ventilation processes were found at roof level, irrespective of the canyon model and wind direction. This supports the idea that sweep and ejection events of momentum bring clean air in and detrain the polluted air from the street canyon, respectively.

  11. Sharing Perspectives and Learning from One Another: Southern Paiutes, Scientists, and Policymakers in the Glen Canyon Dam Adaptive Management Program

    Science.gov (United States)

    Austin, D. E.; Bulletts, K.; Bulletts, C.

    2017-12-01

    The traditional lands of the Southern Paiute people in the United States are bounded by more than 600 miles of the Colorado River from the Kaiparowits Plateau in the north to Blythe, California in the south. According to Southern Paiute traditional knowledge, Southern Paiutes were the first inhabitants of this region and are responsible for protecting and managing this land along with the water and all that is upon and within it. In 1963, the Bureau of Reclamation completed construction of Glen Canyon Dam on the Colorado River, and in 1972, the Glen Canyon National Recreation Area was established, encompassing Lake Mead above the Dam and a world class trout fishery on the Colorado River between the Dam and Lees Ferry. Below Lees Ferry on its way to Lake Mead and Hoover Dam, the Colorado River flows through Grand Canyon National Park and the Navajo and Hualapai reservations. U.S. federal law requires that Glen Canyon Dam be operated with minimal impact to the natural, recreational, and cultural resources of the region of the Colorado River that is potentially impacted by flows from the Dam. The Grand Canyon Protection Act and the Environmental Impact Statement (EIS) for the Operation of the Glen Canyon Dam established a program of long-term research and monitoring of the effects of the Dam on these resources. In 1991, three Southern Paiute tribes - the Kaibab Band of Paiute Indians, the Paiute Indian Tribe of Utah, and the San Juan Southern Paiute Tribe - agreed to participate in studies to identify cultural resources impacted by Glen Canyon Dam and to recommend strategies for their protection, In 1995, the EIS was completed and transition to the Adaptive Management Program (AMP) called for in the Grand Canyon Protection Act was begun. At that time, Southern Paiute activities expanded to include assessing potential environmental and cultural impacts of the dam, developing monitoring procedures, and interacting with scientists, other tribal representatives, and

  12. A comparison of effects from prescribed fires and wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks

    Science.gov (United States)

    Nesmith, C.B.; Caprio, Anthony C.; Pfaff, Anne H.; McGinnis, Thomas W.; Keeley, Jon E.

    2011-01-01

    Current goals for prescription burning are focused on measures of fuel consumption and changes in forest density. These benchmarks, however, do not address the extent to which prescription burning meets perceived ecosystem needs of heterogeneity in burning, both for overstory trees and understory herbs and shrubs. There are still questions about how closely prescribed fires mimic these patterns compared to natural wildfires. This study compared burn patterns of prescribed fires and managed unplanned wildfires to understand how the differing burning regimes affect ecosystem properties. Measures of forest structure and fire severity were sampled in three recent prescribed fires and three wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks. Fine scale patterns of fire severity and heterogeneity were compared between fire types using ground-based measures of fire effects on fuels and overstory and understory vegetation. Prescribed fires and wildfires managed for resource objectives displayed similar patterns of overstory and understory fire severity, heterogeneity, and seedling and sapling survival. Variation among plots within the same fire was always greater than between fire types. Prescribed fires can provide burned landscapes that approximate natural fires in many ways. It is recognized that constraints placed on when wildfires managed for resource objectives are allowed to burn freely may bias the range of conditions that might have been experienced under more natural conditions. Therefore they may not exactly mimic natural wildfires. Overall, the similarity in fire effects that we observed between prescribed fires and managed wildfires indicate that despite the restrictions that are often placed on prescribed fires, they appear to be creating post-fire conditions that approximate natural fires when assessed on a fine spatial scale.

  13. Morphodynamic Model of Submarine Canyon Incision by Sandblasting

    Science.gov (United States)

    Zhang, L.; Parker, G.; Izumi, N.; Cartigny, M.; Li, T.; Wang, G.

    2017-12-01

    Submarine canyons are carved by turbidity currents under the deep sea. As opposed to subaerial canyons, the relevant processes are not easy to observe directly. Turbidity currents are bottom-hugging sediment gravity flows of that can incise or deposit on the seafloor to create submarine canyons or fans. The triggers of turbidity currents can be storms, edge waves, internal waves, canyon wall sapping, delta failure, breaching and hyperpycnal flows. The formation and evolution mechanisms of submarine canyons are similar to those of subaerial canyons, but have substantial differences. For example, sandblasting, rather than wear due to colliding gravel clasts is more likely to be the mechanism of bedrock incision. Submarine canyons incise downward, and often develop meander bends and levees within the canyon, so defining "fairways". Here we propose a simple model for canyon incision. The starting point of our model is the Macro Roughness Saltation Abrasion Alluviation model of Zhang et al. [2015], designed for bedrock incision by gravel clasts in mixed bedrock-alluvial rivers. We adapt this formulation to consider sandblasting as a means of wear. We use a layer-averaged model for turbidity current dynamics. The current contains a mixture of mud, which helps drive the flow but which does not cause incision, and sand, which is the agent of incision. We show that the model can successfully model channel downcutting, and indeed illustrate the early formation of net incisional cyclic steps, i.e. upstream-migrating undulations on the bed associated with transcritical (in the Froude sense) flow. These steps can be expected to abet the process of incision.

  14. Environmental assessment overview, Davis Canyon site, Utah

    International Nuclear Information System (INIS)

    1986-05-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah as one of the nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. The Davis Canyon site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. On the basis of the evaluations reported in this EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. On the basis of these findings, the DOE is nominating the Davis Canyon site as one of five sites suitable for characterization. 3 figs

  15. Transient simulation of groundwater levels within a sandbar of the Colorado River, Marble Canyon, Arizona, 2004

    Science.gov (United States)

    Sabol, Thomas A.; Springer, Abraham E.

    2013-01-01

    Seepage erosion and mass failure of emergent sandy deposits along the Colorado River in Grand Canyon National Park, Arizona, are a function of the elevation of groundwater in the sandbar, fluctuations in river stage, the exfiltration of water from the bar face, and the slope of the bar face. In this study, a generalized three-dimensional numerical model was developed to predict the time-varying groundwater level, within the bar face region of a freshly deposited eddy sandbar, as a function of river stage. Model verification from two transient simulations demonstrates the ability of the model to predict groundwater levels within the onshore portion of the sandbar face across a range of conditions. Use of this generalized model is applicable across a range of typical eddy sandbar deposits in diverse settings. The ability to predict the groundwater level at the onshore end of the sandbar face is essential for both physical and numerical modeling efforts focusing on the erosion and mass failure of eddy sandbars downstream of Glen Canyon Dam along the Colorado River.

  16. Modeling the Effect of Wider Canyons on Urban Heating

    Directory of Open Access Journals (Sweden)

    Rizwan Ahmed Memon

    2011-04-01

    Full Text Available The k-? turbulence model is adopted in this study to simulate the impact of street canyon AR (Aspect Ratios on heating within street canyon. The two-dimensional model was validated for RANS (Reynolds Averaged Navier Stokes and energy transport equations. The validation process confirms that the results of the model for airtemperature and wind speed could be trusted. The application of the said model is carried out to ideal street canyons of ARs (ratio of building-height-to-street-width from 0.4 to 2 with the same boundary conditions. Notably, street canyon aspect ratio was calculated by varying the street width while keeping the building height constant. Results show that the weighted-average-air-temperature within AR 0.4 was around 0.8% (i.e. 2.4K higher than that within AR 2.0. Conversely, there was strong correlation (i.e., R2>0.9 between air temperature within the street canyon and street canyon AR. Results demonstrate stronger influence of vertical velocity on heating within street canyon. Evidently, increased vertical velocity decreased the temperatures. Conversely, temperatures were higher along the leeward side of the canyon in lower ARs.

  17. Anatomy of La Jolla submarine canyon system; offshore southern California

    Science.gov (United States)

    Paull, C.K.; Caress, D.W.; Lundsten, E.; Gwiazda, R.; Anderson, K.; McGann, M.; Conrad, J.; Edwards, B.; Sumner, E.J.

    2013-01-01

    An autonomous underwater vehicle (AUV) carrying a multibeam sonar and a chirp profiler was used to map sections of the seafloor within the La Jolla Canyon, offshore southern California, at sub-meter scales. Close-up observations and sampling were conducted during remotely operated vehicle (ROV) dives. Minisparker seismic-reflection profiles from a surface ship help to define the overall geometry of the La Jolla Canyon especially with respect to the pre-canyon host sediments. The floor of the axial channel is covered with unconsolidated sand similar to the sand on the shelf near the canyon head, lacks outcrops of the pre-canyon host strata, has an almost constant slope of 1.0° and is covered with trains of crescent shaped bedforms. The presence of modern plant material entombed within these sands confirms that the axial channel is presently active. The sand on the canyon floor liquefied during vibracore collection and flowed downslope, illustrating that the sediment filling the channel can easily fail even on this gentle slope. Data from the canyon walls help constrain the age of the canyon and extent of incision. Horizontal beds of moderately cohesive fine-grained sediments exposed on the steep canyon walls are consistently less than 1.232 million years old. The lateral continuity of seismic reflectors in minisparker profiles indicate that pre-canyon host strata extend uninterrupted from outside the canyon underneath some terraces within the canyon. Evidence of abandoned channels and point bar-like deposits are noticeably absent on the inside bend of channel meanders and in the subsurface of the terraces. While vibracores from the surface of terraces contain thin (art seafloor mapping and exploration tools provides a uniquely detailed view of the morphology within an active submarine canyon.

  18. 76 FR 56430 - Boulder Canyon Project

    Science.gov (United States)

    2011-09-13

    ... DEPARTMENT OF ENERGY Western Area Power Administration Boulder Canyon Project AGENCY: Western Area... Project (BCP) electric service provided by the Western Area Power Administration (Western). The Rates will... by the Boulder Canyon Project Act (45 Stat. 1057, December 21, 1928), sits on the Colorado River...

  19. Evaluating potential overlap between pack stock and Sierra Nevada bighorn sheep (Ovis canadensis sierrae) in Sequoia and Kings Canyon National Parks, California

    Science.gov (United States)

    Klinger, Robert C.; Few, Alexandra P.; Knox, Kathleen A.; Hatfield, Brian E.; Clark, Jonathan; German, David W.; Stephenson, Thomas R.

    2015-01-01

    Pack stock (horses, mules, burros, llamas, and goats) are frequently assumed to have negative effects on public lands, but there is a general lack of data to be able to quantify the degree to which this is actually the case. Sequoia and Kings Canyon National Parks have received complaints that pack stock may affect Sierra Nevada bighorn sheep (Ovis canadensis sierrae; SNBS), a federally endangered subspecies that occurs in largely disjunct herds in the Sierra Nevada Range of California. The potential effects are thought to be displacement of SNBS from meadows on their summer range (altered habitat use) or, more indirectly, through changes in SNBS habitat or forage quality. Our goals were to conduct an association analysis to quantify the degree of potential spatial overlap in meadow use between SNBS and pack stock and to compare differences in vegetation community composition, structure, and diversity among meadows with different levels of use by bighorn sheep and pack stock. For the association analysis, we used two approaches: (1) we quantified the proportion of meadows that were within the herd home ranges of bighorn sheep and were potentially open to pack stock, and, (2) we used Monte Carlo simulations and use-availability analyses to compare the proportion of meadows used by bighorn sheep relative to the proportional occurrence or area of meadows available to bighorn sheep that were used by pack stock. To evaluate potential effects of pack stock on meadow plant communities and SNBS forage, we sampled vegetation in 2011 and 2012 at 100 plots to generate data that allowed us to compare:

  20. Pollutant Dilution and Diffusion in Urban Street Canyon Neighboring Streets

    Science.gov (United States)

    Sun, Z.; Fu, Zh. M.

    2011-09-01

    In the present study we investigated the airflow patterns and air quality of a series of typical street canyon combinations, developed a mass balance model to determine the local pollutant dilution rate, and discuss the impact of upstream canyon on the air quality of downstream canyon. The results indicated that the geometrical size of upstream and downstream buildings have significant impacts on the ambient airflow patterns. The pollution distribution within the canyons varies with different building combinations and flow patterns. Within the upstream canyon, pollution always accumulates to the low building side for non-symmetrical canyon, and for symmetrical canyon high level of pollution occurs at the leeward side. The height of the middle and downstream buildings can evidently change the pollutant dispersion direction during the transport process. Within the polluted canyon, the pollutant dilution rate (PDR) also varies with different street canyon combinations. The highest PDR is observed when the upstream buildings are both low buildings no matter the height of downstream building. However, the two cases are likely to contribution pollution to the downstream canyon. The H-L-H combination is mostly against local pollution remove, while the L-H-L case is considered the best optimistic building combination with both the ability of diluting local pollution and not remarkably decreasing air quality of downstream canyon. The current work is expected instructive for city designers to optimize traffic patterns under typical existing geometry or in the development of urban geometry modification for air quality control.

  1. Anatomy of La Jolla submarine canyon system; offshore southern California

    Science.gov (United States)

    Paull, C.K.; Caress, D.W.; Lundsten, E.; Gwiazda, R.; Anderson, K.; McGann, M.; Conrad, J.; Edwards, B.; Sumner, E.J.

    2013-01-01

    An autonomous underwater vehicle (AUV) carrying a multibeam sonar and a chirp profiler was used to map sections of the seafloor within the La Jolla Canyon, offshore southern California, at sub-meter scales. Close-up observations and sampling were conducted during remotely operated vehicle (ROV) dives. Minisparker seismic-reflection profiles from a surface ship help to define the overall geometry of the La Jolla Canyon especially with respect to the pre-canyon host sediments. The floor of the axial channel is covered with unconsolidated sand similar to the sand on the shelf near the canyon head, lacks outcrops of the pre-canyon host strata, has an almost constant slope of 1.0° and is covered with trains of crescent shaped bedforms. The presence of modern plant material entombed within these sands confirms that the axial channel is presently active. The sand on the canyon floor liquefied during vibracore collection and flowed downslope, illustrating that the sediment filling the channel can easily fail even on this gentle slope. Data from the canyon walls help constrain the age of the canyon and extent of incision. Horizontal beds of moderately cohesive fine-grained sediments exposed on the steep canyon walls are consistently less than 1.232 million years old. The lateral continuity of seismic reflectors in minisparker profiles indicate that pre-canyon host strata extend uninterrupted from outside the canyon underneath some terraces within the canyon. Evidence of abandoned channels and point bar-like deposits are noticeably absent on the inside bend of channel meanders and in the subsurface of the terraces. While vibracores from the surface of terraces contain thin (< 10 cm) turbidites, they are inferred to be part of a veneer of recent sediment covering pre-canyon host sediments that underpin the terraces. The combined use of state of the art seafloor mapping and exploration tools provides a uniquely detailed view of the morphology within an active submarine canyon.

  2. 76 FR 8359 - Boulder Canyon Project

    Science.gov (United States)

    2011-02-14

    ... DEPARTMENT OF ENERGY Western Area Power Administration Boulder Canyon Project AGENCY: Western Area... Western Area Power Administration (Western) is proposing an adjustment to the Boulder Canyon Project (BCP... Reclamation Project Act of 1939 (43 U.S.C. 485h(c)), and other acts that specifically apply to the project...

  3. 78 FR 7775 - Boulder Canyon Project

    Science.gov (United States)

    2013-02-04

    ... DEPARTMENT OF ENERGY Western Area Power Administration Boulder Canyon Project AGENCY: Western Area...), is proposing an adjustment to the Boulder Canyon Project (BCP) electric service base charge and rates... subsequent laws, particularly section 9(c) of the Reclamation Project Act of 1939 (43 U.S.C. 485h(c)); and...

  4. 77 FR 2533 - Boulder Canyon Project

    Science.gov (United States)

    2012-01-18

    ... DEPARTMENT OF ENERGY Western Area Power Administration Boulder Canyon Project AGENCY: Western Area...), is proposing an adjustment to the Boulder Canyon Project (BCP) electric service base charge and rates...) of the Reclamation Project Act of 1939 (43 U.S.C. 485h(c)); and other acts that specifically apply to...

  5. Deepwater Canyons 2013: Pathways to the Abyss

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Leg I focused on biological objectives in Norfolk Canyon, with some sampling in Baltimore Canyon. Leg II focused on archaeological targets in and around the Norfolk...

  6. Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

    Science.gov (United States)

    Fu, Xiangwen; Liu, Junfeng; Ban-Weiss, George A.; Zhang, Jiachen; Huang, Xin; Ouyang, Bin; Popoola, Olalekan; Tao, Shu

    2017-09-01

    Street canyons are ubiquitous in urban areas. Traffic-related air pollutants in street canyons can adversely affect human health. In this study, an urban-scale traffic pollution dispersion model is developed considering street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. In the model, vehicle exhausts generated from traffic flows first disperse inside street canyons along the micro-scale wind field generated by computational fluid dynamics (CFD) model. Then, pollutants leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing. We found that an increase in building height leads to heavier pollution inside canyons and lower pollution outside canyons at pedestrian level, resulting in higher domain-averaged concentrations over the area. In addition, canyons with highly even or highly uneven building heights on each side of the street tend to lower the urban-scale air pollution concentrations at pedestrian level. Further, increasing street widths tends to lead to lower pollutant concentrations by reducing emissions and enhancing ventilation simultaneously. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry while considering traffic demand as well as local weather patterns may significantly reduce inhalation of unhealthy air by urban residents.

  7. Development of ecological restoration experiments in fire adapted forests at Grand Canyon National Park

    Science.gov (United States)

    Thomas A. Heinlein; W. Wallace Covington; Peter Z. Fule; Margaret H. Moore; Hiram B. Smith

    2000-01-01

    The management of national park and wilderness areas dominated by forest ecosystems adapted to frequent, low-intensity fires, continues to be a tremendous challenge. Throughout the inland West and particularly in the Southwest, ponderosa pine (Pinus ponderosa) and mixed conifer forests have become dense and structurally homogeneous after periods of...

  8. Characteristics of flow and reactive pollutant dispersion in urban street canyons

    Science.gov (United States)

    Park, Soo-Jin; Kim, Jae-Jin; Kim, Minjoong J.; Park, Rokjin J.; Cheong, Hyeong-Bin

    2015-05-01

    In this study, the effects of aspect ratio defined as the ratio of building height to street width on the dispersion of reactive pollutants in street canyons were investigated using a coupled CFD-chemistry model. Flow characteristics for different aspect ratios were analyzed first. For each aspect ratio, six emission scenarios with different VOC-NOX ratios were considered. One vortex was generated when the aspect ratio was less than 1.6 (shallow street canyon). When the aspect ratio was greater than 1.6 (deep street canyon), two vortices were formed in the street canyons. Comparing to previous studies on two-dimensional street canyons, the vortex center is slanted toward the upwind building and reverse and downward flows are dominant in street canyons. Near the street bottom, there is a marked difference in flow pattern between in shallow and deep street canyons. Near the street bottom, reverse and downward flows are dominant in shallow street canyon and flow convergence exists near the center of the deep street canyons, which induces a large difference in the NOX and O3 dispersion patterns in the street canyons. NOX concentrations are high near the street bottom and decreases with height. The O3 concentrations are low at high NO concentrations near the street bottom because of NO titration. At a low VOC-NOX ratio, the NO concentrations are sufficiently high to destroy large amount of O3 by titration, resulting in an O3 concentration in the street canyon much lower than the background concentration. At high VOC-NOX ratios, a small amount of O3 is destroyed by NO titration in the lower layer of the street canyons. However, in the upper layer, O3 is formed through the photolysis of NO2 by VOC degradation reactions. As the aspect ratio increases, NOX (O3) concentrations averaged over the street canyons decrease (increase) in the shallow street canyons. This is because outward flow becomes strong and NOX flux toward the outsides of the street canyons increases

  9. Lightning safety awareness of visitors in three California national parks.

    Science.gov (United States)

    Weichenthal, Lori; Allen, Jacoby; Davis, Kyle P; Campagne, Danielle; Snowden, Brandy; Hughes, Susan

    2011-09-01

    To assess the level of lightning safety awareness among visitors at 3 national parks in the Sierra Nevada Mountains of California. A 12-question, short answer convenience sample survey was administered to participants 18 years of age and over concerning popular trails and points of interest with known lightning activity. There were 6 identifying questions and 5 knowledge-based questions pertaining to lightning that were scored on a binary value of 0 or 1 for a total of 10 points for the survey instrument. Volunteers in Fresno, California, were used as a control group. Participants were categorized as Sequoia and Kings Canyon National Park (SEKI), frontcountry (FC), or backcountry (BC); Yosemite National Park (YNP) FC or BC; and Fresno. Analysis of variance (ANOVA) was used to test for differences between groups. 467 surveys were included for analysis: 77 in Fresno, 192 in SEKI, and 198 in YNP. National park participants demonstrated greater familiarity with lightning safety than individuals from the metropolitan community (YNP 5.84 and SEKI 5.65 vs Fresno 5.14, P = .0032). There were also differences noted between the BC and FC subgroups (YNP FC 6.07 vs YNP BC 5.62, P = .02; YNP FC 6.07 vs SEKI FC 5.58, P = .02). Overall results showed that participants had certain basic lightning knowledge but lacked familiarity with other key lightning safety recommendations. While there are statistically significant differences in lightning safety awareness between national parks and metropolitan participants, the clinical impact of these findings are debatable. This study provides a starting point for providing educational outreach to visitors in these national parks. Copyright © 2011 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  10. The Glen Canyon Dam Adaptive Management Program: An experiment in science-based resource management

    Science.gov (United States)

    kaplinski, m

    2001-12-01

    In 1996, Glen Canyon Dam Adaptive Management (GCDAMP) program was established to provide input on Glen Canyon Dam operations and their affect on the Colorado Ecosystem in Grand Canyon. The GCDAMP is a bold experiment in federal resource management that features a governing partnership with all relevant stakeholders sitting at the same table. It is a complicated, difficult process where stakeholder-derived management actions must balance resource protection with water and power delivery compacts, the Endangered Species Act, the National Historical Preservation Act, the Grand Canyon Protection Act, National Park Service Policy, and other stakeholder concerns. The program consists of four entities: the Adaptive Management Workgroup (AMWG), the Technical Workgroup (TWG), the Grand Canyon Monitoring and Research Center (GCMRC), and independent review panels. The AMWG and TWG are federal advisory committees that consists of federal and state resource managers, Native American tribes, power, environmental and recreation interests. The AMWG is develops, evaluates and recommends alternative dam operations to the Secretary. The TWG translates AMWG policy and goals into management objectives and information needs, provides questions that serve as the basis for long-term monitoring and research activities, interprets research results from the GCMRC, and prepares reports as required for the AMWG. The GCMRC is an independent science center that is responsible for all GCDAMP monitoring and research activities. The GCMRC utilizes proposal requests with external peer review and an in-house staff that directs and synthesizes monitoring and research results. The GCMRC meets regularly with the TWG and AMWG and provides scientific information on the consequences of GCDAMP actions. Independent review panels consist of external peer review panels that provide reviews of scientific activities and the program in general, technical advice to the GCMRC, TWG and AMWG, and play a critical

  11. The Upper Danube Nature Park

    International Nuclear Information System (INIS)

    Dosedla, H.C.

    1997-01-01

    When in 1980 the Upper Danube Nature Park was founded as one of 65 nature sanctuaries in Germany there was great diversity of opinions concerning its intended character. The protected region consisting of a geologically outstanding landscape within central Europe is covering the first 80 km the upper Danube where the young river shortly after it's source in the Black Forest is breaking through the narrow canyons of the Jurassic rock plateau of the so-called Suebian Alps and also locates the subterranean passage where the stream is submerging from the surface for nearly ten miles. Since the purpose of nature preservation according to German las is closely combined with the rather contradicting aim of offering an attractive recreation area thus facing the immense impacts of modern mass tourism there are numerous problems which in the course of years have resulted in an intricate patterns of subtle management methods coping with the growing awareness of the ecological balance. (author)

  12. Davis Canyon noise analysis: Revision 2

    International Nuclear Information System (INIS)

    1985-11-01

    A study was performed as part of the Civilian Radioactive Waste Management Program to quantify the level and effect of noise from the various major phases of development of the proposed potentially acceptable nuclear waste repository site at Davis Canyon, Utah. This report contains the results of a predictive noise level study for the site characterization, repository construction, and repository operational phases. Included herein are graphic representations of energy averaged sound levels, and of audibility levels representing impact zones expected during each phase. Sound levels from onsite and offsite activity including traffic on highways and railroad routes are presented in isopleth maps. A description of the Environmental Noise Prediction Model used for the study, the study basis and methodologies, and actual modeling data are provided. Noise and vibration levels from blasting are also predicted and evaluated. Protective noise criteria containing a margin of safety are used in relation to residences, schools, churches, noise-sensitive recreation areas, and noise-sensitive biological resources. Protective ground motion criteria for ruins and delicate rock formation in Canyonlands National Park and for human annoyance are used in the evaluation of blasting. The evaluations provide the basis for assessing the noise impacts from the related activities at the proposed repository. 45 refs., 21 figs., 15 tabs

  13. 77 FR 22801 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2012-04-17

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group...). SUMMARY: The Glen Canyon Dam Adaptive Management Work Group (AMWG) makes recommendations to the Secretary..., the AMWG, a technical work group, a Grand Canyon Monitoring and Research Center, and independent...

  14. Modelling the air flow in symmetric and asymmetric street canyons

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, J.L.; Martin, F. [Research Center for Energy, Environment and Technology (CIEMAT), Madrid (Spain). Fossil Fuels Dept., Numerical Simulation and Modelling Program

    2004-07-01

    In recent years a large amount of research has been conducted on urban scale and street canyon. Control of air quality inside cities is important for human health. To achieve this objective, street canyon modelling plays a significant role. Pollutant dispersion inside canyons are determined by wind flow around this complex geometry. Experimental investigations have been made by means of field measurements such as Vachon, G. et al. or wind tunnel experiences as Meroney, R.N. et al. or Kastner-Klein, P. and E.J. Plate. In many of these researches, they have used CFD models in several configurations, for instance Assimakopoulos, V.D. et al. or Sini, J.-F. et al. These models are based on a numerical resolution of Navier-Stokes equations with a turbulence closure. In this study, the aim is contribute to the understanding of air circulation inside street canyons. In order to achieve this purpose, several configurations of canyons are investigated. Two-dimensional sequences of real-scale street canyons (order to obstacles height is meters) with different features (symmetric canyons and asymmetric canyons forming step-up and step-down notch configurations) are simulated. These general configurations are modified to investigate some parameters such as aspect ratio, W/H, where W is the width of street and H is the height of buildings. Flows with high Reynolds numbers are modelling. FLUENT CFD software is used. (orig.)

  15. Mesohabitats, fish assemblage composition, and mesohabitat use of the Rio Grande silvery minnow over a range of seasonal flow regimes in the Rio Grande/Rio Bravo del Norte, in and near Big Bend National Park, Texas, 2010-11

    Science.gov (United States)

    Moring, J. Bruce; Braun, Christopher L.; Pearson, Daniel K.

    2014-01-01

    In 2010–11, the U.S. Geological Survey (USGS), in cooperation with the U.S. Fish and Wildlife Service, evaluated the physical characteristics and fish assemblage composition of mapped river mesohabitats at four sites on the Rio Grande/Rio Bravo del Norte (hereinafter Rio Grande) in and near Big Bend National Park, Texas. The four sites used for the river habitat study were colocated with sites where the U.S. Fish and Wildlife Service has implemented an experimental reintroduction of the Rio Grande silvery minnow (Hybognathus amarus), a federally listed endangered species, into part of the historical range of this species. The four sites from upstream to downstream are USGS station 08374340 Rio Grande at Contrabando Canyon near Lajitas, Tex. (hereinafter the Contrabando site), USGS station 290956103363600 Rio Grande at Santa Elena Canyon, Big Bend National Park, Tex. (hereinafter the Santa Elena site), USGS station 291046102573900 Rio Grande near Ranger Station at Rio Grande Village, Tex. (hereinafter the Rio Grande Village site), and USGS station 292354102491100 Rio Grande above Stillwell Crossing near Big Bend National Park, Tex. (hereinafter the Stillwell Crossing site).

  16. Crossing fitness canyons by a finite population

    Science.gov (United States)

    Saakian, David B.; Bratus, Alexander S.; Hu, Chin-Kun

    2017-06-01

    We consider the Wright-Fisher model of the finite population evolution on a fitness landscape defined in the sequence space by a path of nearly neutral mutations. We study a specific structure of the fitness landscape: One of the intermediate mutations on the mutation path results in either a large fitness value (climbing up a fitness hill) or a low fitness value (crossing a fitness canyon), the rest of the mutations besides the last one are neutral, and the last sequence has much higher fitness than any intermediate sequence. We derive analytical formulas for the first arrival time of the mutant with two point mutations. For the first arrival problem for the further mutants in the case of canyon crossing, we analytically deduce how the mean first arrival time scales with the population size and fitness difference. The location of the canyon on the path of sequences has a crucial role. If the canyon is at the beginning of the path, then it significantly prolongs the first arrival time; otherwise it just slightly changes it. Furthermore, the fitness hill at the beginning of the path strongly prolongs the arrival time period; however, the hill located near the end of the path shortens it. We optimize the first arrival time by applying a nonzero selection to the intermediate sequences. We extend our results and provide a scaling for the valley crossing time via the depth of the canyon and population size in the case of a fitness canyon at the first position. Our approach is useful for understanding some complex evolution systems, e.g., the evolution of cancer.

  17. [Effect of greenbelt on pollutant dispersion in street canyon].

    Science.gov (United States)

    Xu, Wei-Jia; Xing, Hong; Yu, Zhi

    2012-02-01

    The effect feature of greenbelt on flow field and pollutant dispersion in urban street canyon was researched. The greenbelt was assumed as uniform porous media and its aerodynamics property defined by the pressure loss coefficient. Subsequently, the pollutant dispersion in the street canyon of which there was greenbelt in the middle was simulated with the steady-state standard kappa-epsilon turbulence model and species transport equation. The simulated results agreed well with the wind-tunnel data. Compared with the treeless case, it finds that the street canyon contain a clockwise vortex, the pollutant concentration of the leeward was several times than the windward and the growth rate of pollutant concentration was 46.0%. The further simulation for the impact of tree crown position on the airflow and pollutant dispersion finds that the height of major vortex center in the street canyon increases with the height of tree crown and gradually closes the top of windward building This causes that the average wind speed in the street canyon decreases. Especially when the top of tree crown over the roof and hinder the air flow above the street canyon, the average pollutant concentration increases with the height of tree crown rapidly.

  18. Monitoring riparian-vegetation composition and cover along the Colorado River downstream of Glen Canyon Dam, Arizona

    Science.gov (United States)

    Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel A.; Johnson, Taylor C.

    2018-06-05

    Vegetation in the riparian zone (the area immediately adjacent to streams, such as stream banks) along the Colorado River downstream of Glen Canyon Dam, Arizona, supports many ecosystem and societal functions. In both Glen Canyon and Grand Canyon, this ecosystem has changed over time in response to flow alterations, invasive species, and recreational use. Riparian-vegetation cover and composition are likely to continue to change as these pressures persist and new ones emerge. Because this system is a valuable resource that is known to change in response to flow regime and other disturbances, a long-term monitoring protocol has been designed with three primary objectives:Annually measure and summarize the status (composition and cover) of native and non-native vascular-plant species within the riparian zone of the Colorado River between Glen Canyon Dam and Lake Mead.At 5-year intervals, assess change in vegetation composition and cover in the riparian zone, as related to geomorphic setting and dam operations, particularly flow regime.Collect data in a manner that can be used by multiple stakeholders, particularly the basinwide monitoring program overseen by the National Park Service’s Northern Colorado Plateau Network Inventory and Monitoring program.A protocol for the long-term monitoring of riparian vegetation is described in detail and standard operating procedures are included herein for all tasks. Visual estimates of foliar and ground covers are collected in conjunction with environmental measurements to assess correlations of foliar cover with abiotic and flow variables. Sample quadrats are stratified by frequency of inundation, geomorphic feature, and by river segment to account for differences in vegetation type. Photographs of sites are also taken to illustrate qualitative characteristics of the site at the time of sampling. Procedures for field preparation, generating random samples, data collection, data management, collecting and managing unknown

  19. Geomorphic Thresholds of Submarine Canyons Along the U.S. Atlantic Continental Margin

    Science.gov (United States)

    Brothers, D. S.; ten Brink, U. S.; Andrews, B. D.; Chaytor, J. D.

    2011-12-01

    Vast networks of submarine canyons and associated channels are incised into the U.S. Atlantic continental slope and rise. Submarine canyons form by differential erosion and deposition, primarily from sedimentary turbidity flows. Theoretical and laboratory studies have investigated the initiation of turbidity flows and their capacity to erode and entrain sedimentary material at distances far from the shelf edge. The results have helped understand the nature of turbidite deposits on the continental slope and rise. Nevertheless, few studies have examined the linkages between down-canyon sediment transport and the morphology of canyon/channel networks using mesoscale analyses of swath bathymetry data. We present quantitative analysis of 100-m resolution multibeam bathymetry data spanning ~616,000 km2 of the slope and rise between Georges Banks and the Blake Plateau (New England to North Carolina). Canyons are categorized as shelf-indenting or slope-confined based on spatial scale, vertical relief and connection with terrestrial river systems during sea level low stands. Shelf-indenting canyons usually represent the trunk-canyon of submerged channel networks. On the rise, shelf-indenting canyons have relatively well-developed channel-levees and sharp inner-thalwag incision suggesting much higher frequency and volume of turbidity flows. Because of the similarities between submarine canyon networks and terrestrial river systems, we apply methods originally developed to study fluvial morphology. Along-canyon profiles are extracted from the bathymetry data and the power-law relationship between thalwag gradient and drainage area is examined for more than 180 canyons along an ~1200 km stretch of the US Atlantic margin. We observe distinct thresholds in the power-law relationship between drainage area and gradient. Almost all canyons with heads on the upper slope contain at least two linear segments when plotted in log-log form. The first segment along the upper slope is flat

  20. H Canyon Processing In Correlation With FH Analytical Labs

    International Nuclear Information System (INIS)

    Weinheimer, E.

    2012-01-01

    Management of radioactive chemical waste can be a complicated business. H Canyon and F/H Analytical Labs are two facilities present at the Savannah River Site in Aiken, SC that are at the forefront. In fact H Canyon is the only large-scale radiochemical processing facility in the United States and this processing is only enhanced by the aid given from F/H Analytical Labs. As H Canyon processes incoming materials, F/H Labs provide support through a variety of chemical analyses. Necessary checks of the chemical makeup, processing, and accountability of the samples taken from H Canyon process tanks are performed at the labs along with further checks on waste leaving the canyon after processing. Used nuclear material taken in by the canyon is actually not waste. Only a small portion of the radioactive material itself is actually consumed in nuclear reactors. As a result various radioactive elements such as Uranium, Plutonium and Neptunium are commonly found in waste and may be useful to recover. Specific processing is needed to allow for separation of these products from the waste. This is H Canyon's specialty. Furthermore, H Canyon has the capacity to initiate the process for weapons-grade nuclear material to be converted into nuclear fuel. This is one of the main campaigns being set up for the fall of 2012. Once usable material is separated and purified of impurities such as fission products, it can be converted to an oxide and ultimately turned into commercial fuel. The processing of weapons-grade material for commercial fuel is important in the necessary disposition of plutonium. Another processing campaign to start in the fall in H Canyon involves the reprocessing of used nuclear fuel for disposal in improved containment units. The importance of this campaign involves the proper disposal of nuclear waste in order to ensure the safety and well-being of future generations and the environment. As processing proceeds in the fall, H Canyon will have a substantial

  1. CODASC : a database for the validation of street canyon dispersion models

    OpenAIRE

    Gromke, C.B.

    2013-01-01

    CODASC stands for Concentration Data of Street Canyons (CODASC 2008, www.codasc.de). It is a database which provides traffic pollutant concentrations in urban street canyons obtained from wind-tunnel dispersion experiments. CODASC comprises concentration data of street canyons with different aspect ratios subjected to various wind directions and also for street canyons with tree-avenues. The database includes concentration data of tree-avenue configurations of different tree arrangement, tree...

  2. Dispersion and photochemical evolution of reactive pollutants in street canyons

    Science.gov (United States)

    Kwak, Kyung-Hwan; Baik, Jong-Jin; Lee, Kwang-Yeon

    2013-05-01

    Dispersion and photochemical evolution of reactive pollutants in street canyons with canyon aspect ratios of 1 and 2 are investigated using a computational fluid dynamics (CFD) model coupled with the carbon bond mechanism IV (CBM-IV). Photochemical ages of NOx and VOC are expressed as a function of the NO2-to-NOx and toluene-to-xylene ratios, respectively. These are found to be useful for analyzing the O3 and OH oxidation processes in the street canyons. The OH oxidation process (O3 oxidation process) is more pronounced in the upper (lower) region of the street canyon with a canyon aspect ratio of 2, which is characterized by more (less) aged air. In the upper region of the street canyon, O3 is chemically produced as well as transported downward across the roof level, whereas O3 is chemically reduced in the lower region of the street canyon. The O3 chemical production is generally favorable when the normalized photochemical ages of NOx and VOC are larger than 0.55 and 0.28, respectively. The sensitivities of O3 chemical characteristics to NOx and VOC emission rates, photolysis rate, and ambient wind speed are examined for the lower and upper regions of the street canyon with a canyon aspect ratio of 2. The O3 concentration and the O3 chemical production rate divided by the O3 concentration increase as the NOx emission rate decreases and the VOC emission rate and photolysis rate increase. The O3 concentration is less sensitive to the ambient wind speed than to other factors considered. The relative importance of the OH oxidation process compared to the O3 oxidation process increases with increasing NOx emission rate and photolysis rate and decreasing VOC emission rate. In this study, both O3 and OH oxidation processes are found to be important in street-canyon scale chemistry. The methodology of estimating the photochemical ages can potentially be adopted to neighborhood scale chemistry.

  3. Populating a Control Point Database: A cooperative effort between the USGS, Grand Canyon Monitoring and Research Center and the Grand Canyon Youth Organization

    Science.gov (United States)

    Brown, K. M.; Fritzinger, C.; Wharton, E.

    2004-12-01

    The Grand Canyon Monitoring and Research Center measures the effects of Glen Canyon Dam operations on the resources along the Colorado River from Glen Canyon Dam to Lake Mead in support of the Grand Canyon Adaptive Management Program. Control points are integral for geo-referencing the myriad of data collected in the Grand Canyon including aerial photography, topographic and bathymetric data used for classification and change-detection analysis of physical, biologic and cultural resources. The survey department has compiled a list of 870 control points installed by various organizations needing to establish a consistent reference for data collected at field sites along the 240 mile stretch of Colorado River in the Grand Canyon. This list is the foundation for the Control Point Database established primarily for researchers, to locate control points and independently geo-reference collected field data. The database has the potential to be a valuable mapping tool for assisting researchers to easily locate a control point and reduce the occurrance of unknowingly installing new control points within close proximity of an existing control point. The database is missing photographs and accurate site description information. Current site descriptions do not accurately define the location of the point but refer to the project that used the point, or some other interesting fact associated with the point. The Grand Canyon Monitoring and Research Center (GCMRC) resolved this problem by turning the data collection effort into an educational exercise for the participants of the Grand Canyon Youth organization. Grand Canyon Youth is a non-profit organization providing experiential education for middle and high school aged youth. GCMRC and the Grand Canyon Youth formed a partnership where GCMRC provided the logistical support, equipment, and training to conduct the field work, and the Grand Canyon Youth provided the time and personnel to complete the field work. Two data

  4. The timing of sediment transport down Monterey Submarine Canyon, offshore California

    DEFF Research Database (Denmark)

    Stevens, Thomas; Paull, C.K.; Ussler, W., III

    2014-01-01

    luminescence (OSL) ages of quartz sand deposits and accelerator mass spectrometry 14C ages measured on benthic foraminifera to examine the timing of sediment transport through the axial channel of Monterey Submarine Canyon and Fan, offshore California. The OSL ages date the timing of sediment entry...... dates with water depth provides evidence of mixing and temporary storage of sediment as it moves through the canyon system. The ages also indicate that the frequency of sediment transport events decreases with distance down the canyon channel system. The amalgamated sands near the canyon head yield OSL......While submarine canyons are the major conduits through which sediments are transported from the continents out into the deep sea, the time it takes for sediment to pass down through a submarine canyon system is poorly constrained. Here we report on the first study to couple optically stimulated...

  5. Surficial Geology of Mount Rainier National Park, Washington

    Science.gov (United States)

    Crandell, Dwight Raymond

    1969-01-01

    Much of the ground surface around Mount Rainier volcano is directly underlain by loose geologic deposits that veneer the hard rock formations. Examples of these deposits are sand and gravel bars along the rivers, ridges of loose rock debris beside the glaciers, and sloping aprons of rock fragments beneath almost every cliff. Even though they are generally thin and inconspicuous when compared with the rock formations, these surficial deposits are clues to geologic events that have profoundly influenced the shape of the park's landscape. Thus, from the character and extent of glacial deposits one can judge the age and size of former glaciers that carved the cirques and deep canyons of the park; from the mudflows which streamed down nearly every valley one can infer the age and size of huge landslides of the past that helped determine Mount Rainier's present shape; and from the pumice deposits some of the volcano's recent eruptive activity can be reconstructed. The map (plate 1, in pocket) that accompanies this description of the surficial deposits of Mount Rainier National Park shows the location of the various geologic formations, and the explanation shows the formations arranged in order of their relative age, with the oldest at the bottom. The text describes the surficial deposits in sequence from older to younger. A discussion of the pumice deposits of the park, which were not mapped, is followed by a description of the formations shown on the geologic map. Inspection of the geologic map may lead the viewer to question why the surficial deposits are shown in more detail in a zone several miles wide around the base of the volcano than elsewhere. This is partly because the zone is largely near or above timberline, relatively accessible, and the surficial deposits there can be readily recognized, differentiated, and mapped. In contrast, access is more difficult in the heavily timbered parts of the park, and surficial deposits there are generally blanketed by a dense

  6. Evolution and Submarine Landslide Potential of Monterey Canyon Head, Offshore Central California

    Science.gov (United States)

    Maier, K. L.; Johnson, S. Y.; Hart, P. E.; Hartwell, S. R.

    2016-12-01

    Monterey Canyon, offshore central California, incises the shelf from near the shoreline to 30 km seaward where axial water depths approach 2,000 m. It is one of the world's most studied submarine canyons, yet debate continues concerning its age, formation, and associated geologic hazards. To address these issues, the USGS, with partial support from the California Seafloor Mapping Program, collected hundreds of kilometers of high-resolution, mini-sparker, single-channel (2009 and 2011 surveys) and multichannel (2015 survey) seismic-reflection profiles near the canyon head. The seismic data were combined with multibeam bathymetry to generate a geologic map of the proximal canyon, which delineates numerous faults and compound submarine landslide headwall scarps (covering up to 4 km2) along canyon walls. Seismic-reflection data reveal a massive ( 100 km2 lateral extent) paleochannel cut-and-fill complex underlying the proximal canyon. These subsurface cut-and-fill deposits span both sides of the relatively narrow modern canyon head, crop out in canyon walls, and incise into Purisima Formation (late Miocene and Pliocene) bedrock to depths of up to 0.3 s two-way travel time ( 240 m) below the modern shelf. We propose that the paleochannel complex represents previous locations of a migrating canyon head, and attribute its origin to multiple alternating cycles of fluvial and submarine canyon erosion and deposition linked to fluctuating sea levels. Thus, the canyon head imaged in modern bathymetry is a relatively young feature, perhaps forming in the last 20,000 years of sea-level rise. The paleocanyon deposits are significantly less consolidated than bedrock in deeper canyon walls, and therefore, are probably more prone to submarine landsliding. Nearby mapped faults occur within the active, distributed, San Andreas fault system, and earthquake-generated strong ground motions are likely triggers for past and future submarine landslides and potential associated tsunamis.

  7. Strategic guidelines for street canyon geometry to achieve sustainable street air quality

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Andy T.; So, Ellen S.P.; Samad, Subash C. [Hong Kong Univ., Dept. of Mechanical Engineering, Hong Kong (China)

    2001-08-01

    This paper is concerned with the motion of air within the urban street canyon and is directed towards a deeper understanding of pollutant dispersion with respect to various simple canyon geometries and source positions. Taking into account the present days typical urban configurations, three principal flow regimes 'isolated roughness flow', 'skimming flow' and 'wake interference flow' (Boundary Layer Climates, 2nd edition, Methuen, London) and their corresponding pollutant dispersion characteristics are studied for various canopies aspect ratios, namely relative height (h{sub 2}/H{sub 1}), canyon height to width ratio (h/w) and canyon length to height ratio (l/h). A field-size canyon has been analysed through numerical simulations using the standard k-{sup {epsilon}} turbulence closure model. It is found that the pollutant transport and diffusion is strongly dependent upon the type of flow regime inside the canyon and exchange between canyon and the above roof air. Some rules of thumbs have been established to get urban canyon geometries for efficient dispersion of pollutants. (Author)

  8. CODASC : a database for the validation of street canyon dispersion models

    NARCIS (Netherlands)

    Gromke, C.B.

    2013-01-01

    CODASC stands for Concentration Data of Street Canyons (CODASC 2008, www.codasc.de). It is a database which provides traffic pollutant concentrations in urban street canyons obtained from wind-tunnel dispersion experiments. CODASC comprises concentration data of street canyons with different aspect

  9. Is Canyon Width a Diagnostic Indicator of the Discharge of Megafloods on Earth and Mars?

    Science.gov (United States)

    Lapotre, M. G.; Lamb, M. P.

    2013-12-01

    On Earth, large floods have carved steep-walled and amphitheater-headed canyons from the Pleistocene (e.g. Box Canyon, ID) through the Holocene (e.g. Asbyrgi Canyon, Iceland), to historic times (e.g. Canyon Lake Gorge, TX). The geologic record on Mars suggests that similar floods have carved canyons by waterfall retreat about 3.5 billion years ago, when the red planet was wetter and possibly warmer. We currently lack robust paleo-hydraulic tools to reconstruct the discharge of ancient floods, especially on Mars where sediment sizes are obscured from observation. To address this issue, we hypothesize that the width of canyon escarpment is controlled by the hydraulics of the canyon-carving flood due to focusing of the flood into the canyon head. We compiled field data from multiple canyons and floods on Earth and Mars and show that there is a correlation between estimated flood discharge and canyon headwall width. To explore what sets this relationship, we identified five important parameters using dimensional analysis: the Froude number, the ratio of backwater length to canyon length, the ratio of backwater length to flood width, the ratio of canyon width to flood width, and the topographic slope upstream of the canyon. We used the hydraulic numerical modeling suite ANUGA to simulate overland flow over different canyon geometries and flood parameters to systematically explore the relative bed shear stresses along the canyon rim as a metric for flow focusing. Results show that canyons that exceed a certain length, scaling with the hydraulic backwater length, have shear stresses at their heads that are significantly higher than near the canyon mouth. Shear stresses along the rim of the canyon sidewalls are limited, in comparison to stresses along the canyon head, when the flood width is of the order of the backwater length. Flow focusing only occurs for subcritical flow. Together, these results suggest that canyons may only grow from a perturbation that is large

  10. Formation of sheeting joints in Yosemite National Park, California

    Science.gov (United States)

    Martel, S. J.

    2009-04-01

    -parallel stresses, typically about -10 MPa, meet the requirement above. In apparent violation of hypothesis 1, however, sheeting joints occur locally at the bottom of Tenaya Canyon, one of the park's deepest glaciated, U-shaped (concave) canyons in Yosemite. The sheeting joints occur only where the canyon is convex in the downstream direction though, and that is the approximate direction of the most compressive stress based on nearby stress measurements. Apparently the effect of the least compressive stress acting across the valley, which acts to close the joints, is overcome by the effect of the most compressive stress acting along the down-valley convex curvature, which promotes the opening of the joints.

  11. Heterogeneous Parking Market Subject to Parking Rationing

    Directory of Open Access Journals (Sweden)

    Saeed Asadi Bagloee

    2015-01-01

    Full Text Available Different types of drivers and parking spaces delineate a heterogeneous parking market for which the literature has yet to provide a model applicable to the real world. The main obstacle is computational complexities of considering various parking restrictions along with traffic congestion on the road network. In this study, the heterogeneity aspects are considered within a Logit parking choice model. A mathematical programming problem was introduced to explicitly consider parking capacities and parking rationing constraints. The parking rationing is defined as any arrangement to reserve parking space for some specific demand such as parking permit, private parking, VIP parking, and different parking durations. Introduction of parking rationing in the presence of other constraints is a unique factor in this study which makes the model more realistic. The algorithm was tested on a central business district case study. The results prove that the algorithm is able to converge rapidly. Among the algorithm’s output are shadow prices of the parking capacity and parking rationing constraints. The shadow prices contain important information which is key to addressing a variety of parking issues, such as the location of parking shortages, identification of fair parking charges, viability of parking permits, and the size of reserved parking.

  12. Review: The distribution, flow, and quality of Grand Canyon Springs, Arizona (USA)

    Science.gov (United States)

    Tobin, Benjamin W.; Springer, Abraham E.; Kreamer, David K.; Schenk, Edward

    2018-05-01

    An understanding of the hydrogeology of Grand Canyon National Park (GRCA) in northern Arizona, USA, is critical for future resource protection. The 750 springs in GRCA provide both perennial and seasonal flow to numerous desert streams, drinking water to wildlife and visitors in an otherwise arid environment, and habitat for rare, endemic and threatened species. Spring behavior and flow patterns represent local and regional patterns in aquifer recharge, reflect the geologic structure and stratigraphy, and are indicators of the overall biotic health of the canyon. These springs, however, are subject to pressures from water supply development, changes in recharge from forest fires and other land management activities, and potential contamination. Roaring Springs is the sole water supply for residents and visitors (>6 million/year), and all springs support valuable riparian habitats with very high species diversity. Most springs flow from the karstic Redwall-Muav aquifer and show seasonal patterns in flow and water chemistry indicative of variable aquifer porosities, including conduit flow. They have Ca/Mg-HCO3 dominated chemistry and trace elements consistent with nearby deep wells drilled into the Redwall-Muav aquifer. Tracer techniques and water-age dating indicate a wide range of residence times for many springs, supporting the concept of multiple porosities. A perched aquifer produces small springs which issue from the contacts between sandstone and shale units, with variable groundwater residence times. Stable isotope data suggest both an elevational and seasonal difference in recharge between North and South Rim springs. This review highlights the complex nature of the groundwater system.

  13. Automated remote cameras for monitoring alluvial sandbars on the Colorado River in Grand Canyon, Arizona

    Science.gov (United States)

    Grams, Paul E.; Tusso, Robert B.; Buscombe, Daniel

    2018-02-27

    Automated camera systems deployed at 43 remote locations along the Colorado River corridor in Grand Canyon National Park, Arizona, are used to document sandbar erosion and deposition that are associated with the operations of Glen Canyon Dam. The camera systems, which can operate independently for a year or more, consist of a digital camera triggered by a separate data controller, both of which are powered by an external battery and solar panel. Analysis of images for categorical changes in sandbar size show deposition at 50 percent or more of monitoring sites during controlled flood releases done in 2012, 2013, 2014, and 2016. The images also depict erosion of sandbars and show that erosion rates were highest in the first 3 months following each controlled flood. Erosion rates were highest in 2015, the year of highest annual dam release volume. Comparison of the categorical estimates of sandbar change agree with sandbar change (erosion or deposition) measured by topographic surveys in 76 percent of cases evaluated. A semiautomated method for quantifying changes in sandbar area from the remote-camera images by rectifying the oblique images and segmenting the sandbar from the rest of the image is presented. Calculation of sandbar area by this method agrees with sandbar area determined by topographic survey within approximately 8 percent and allows quantification of sandbar area monthly (or more frequently).

  14. Canyon formation constraints on the discharge of catastrophic outburst floods of Earth and Mars

    Science.gov (United States)

    Lapotre, Mathieu G. A.; Lamb, Michael P.; Williams, Rebecca M. E.

    2016-07-01

    Catastrophic outburst floods carved amphitheater-headed canyons on Earth and Mars, and the steep headwalls of these canyons suggest that some formed by upstream headwall propagation through waterfall erosion processes. Because topography evolves in concert with water flow during canyon erosion, we suggest that bedrock canyon morphology preserves hydraulic information about canyon-forming floods. In particular, we propose that for a canyon to form with a roughly uniform width by upstream headwall retreat, erosion must occur around the canyon head, but not along the sidewalls, such that canyon width is related to flood discharge. We develop a new theory for bedrock canyon formation by megafloods based on flow convergence of large outburst floods toward a horseshoe-shaped waterfall. The model is developed for waterfall erosion by rock toppling, a candidate erosion mechanism in well fractured rock, like columnar basalt. We apply the model to 14 terrestrial (Channeled Scablands, Washington; Snake River Plain, Idaho; and Ásbyrgi canyon, Iceland) and nine Martian (near Ares Vallis and Echus Chasma) bedrock canyons and show that predicted flood discharges are nearly 3 orders of magnitude less than previously estimated, and predicted flood durations are longer than previously estimated, from less than a day to a few months. Results also show a positive correlation between flood discharge per unit width and canyon width, which supports our hypothesis that canyon width is set in part by flood discharge. Despite lower discharges than previously estimated, the flood volumes remain large enough for individual outburst floods to have perturbed the global hydrology of Mars.

  15. California State Waters Map Series—Monterey Canyon and vicinity, California

    Science.gov (United States)

    Dartnell, Peter; Maier, Katherine L.; Erdey, Mercedes D.; Dieter, Bryan E.; Golden, Nadine E.; Johnson, Samuel Y.; Hartwell, Stephen R.; Cochrane, Guy R.; Ritchie, Andrew C.; Finlayson, David P.; Kvitek, Rikk G.; Sliter, Ray W.; Greene, H. Gary; Davenport, Clifton W.; Endris, Charles A.; Krigsman, Lisa M.; Dartnell, Peter; Cochran, Susan A.

    2016-06-10

    IntroductionIn 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath bathymetry data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow subsurface geology.The Monterey Canyon and Vicinity map area lies within Monterey Bay in central California. Monterey Bay is one of the largest embayments along the west coast of the United States, spanning 36 km from its northern to southern tips (in Santa Cruz and Monterey, respectively) and 20 km along its central axis. Not only does it contain one of the broadest sections of continental shelf along California’s coast, it also contains Monterey Canyon, one of the largest and deepest submarine canyons in the world. Note that the California’s State Waters limit extends farther offshore between Santa Cruz and Monterey so that it encompasses all of Monterey Bay.The coastal area within the map area is lightly populated. The community of Moss Landing (population, 204) hosts the largest commercial fishing fleet in Monterey Bay in its harbor. The map area also includes parts of the cities of Marina (population, about 20,000) and Castroville (population, about 6,500). Fertile lowlands of the Salinas River and Pajaro River valleys largely occupy the inland part of the map area, and land use is primarily agricultural.The offshore part of the map area lies completely within the Monterey Bay National Marine Sanctuary. The

  16. Submarine canyons as coral and sponge habitat on the eastern Bering Sea slope

    Directory of Open Access Journals (Sweden)

    Robert J. Miller

    2015-07-01

    Full Text Available Submarine canyons have been shown to positively influence pelagic and benthic biodiversity and ecosystem function. In the eastern Bering Sea, several immense canyons lie under the highly productive “green belt” along the continental slope. Two of these, Pribilof and Zhemchug canyons, are the focus of current conservation interest. We used a maximum entropy modeling approach to evaluate the importance of these two canyons, as well as canyons in general, as habitat for gorgonian (alcyonacean corals, pennatulacean corals, and sponges, in an area comprising most of the eastern Bering Sea slope and outer shelf. These invertebrates create physical structure that is a preferred habitat for many mobile species, including commercially important fish and invertebrates. We show that Pribilof canyon is a hotspot of structure-forming invertebrate habitat, containing over 50% of estimated high-quality gorgonian habitat and 45% of sponge habitat, despite making up only 1.7% of the total study area. The amount of quality habitat for gorgonians and sponges varied in other canyons, but canyons overall contained more high-quality habitat for structure-forming invertebrates compared to other slope areas. Bottom trawling effort was not well correlated with habitat quality for structure-forming invertebrates, and bottom-contact fishing effort in general, including longlining and trawling, was not particularly concentrated in the canyons examined. These results suggest that if conserving gorgonian coral habitat is a management goal, canyons, particularly Pribilof Canyon, may be a prime location to do this without excessive impact on fisheries.

  17. Facies and depositional model of Almada Canyon, Almada Basin, Bahia, Brazil; Facies e modelo deposicional do Canyon de Almada, Bacia de Almada, Bahia

    Energy Technology Data Exchange (ETDEWEB)

    D' Avila, Roberto Salvador Francisco; Souza Cruz, Carlos Emanoel de; Oliveira Filho, Jose Souto; Jesus, Candida Menezes de; Cesero, Pedro de; Dias Filho, Dorval Carvalho; Lima, Claudio Coelho de; Queiroz, Claudia Lima de; Santos, Saulo Ferreira; Ferreira, Eduardo Araripe [PETROBRAS, Santos, SP (Brazil). Unidade de Negocio de Exploracao]. E-mail: rdavila@petrobras.com.br

    2004-11-01

    In the continental portion of the Almada Basin outcrops of canyon filling deposits are represented by turbidite channels and associated facies from Urucutuca Formation. The canyon - semi-exhumated - eroded basement and pre-Cenomanian sedimentary rocks. The field study of the outcrops and cores obtained in adjacent perforations lead to the understanding of the facies and processes that controlled the deposition of these channeled turbidite that can be compared to the reservoirs of many oil fields in Brazil. The Almada canyon is a submarine conduct of tectonic origin that was enlarged by the repeated passing of turbidity currents. During the rift phase and the Albian period, compressive events reactivated old N E and N W faults in the basement as trans current fault systems. The continuation of these stresses, from the Cenomanian to the Maastrichtian, developed normal faults that controlled a submarine canyon that connected the continent, where an estuary was formed between the mountains, to the deep marine region of the basin. The canyon has received sediments brought by catastrophic fluvial floods coming from the surrounding mountains, which formed hyperpicnal flows that have evolved as turbidity currents, thus causing erosion of the substrate and carrying a huge volume of sediments to the basin. A part of that load was deposited in the canyon and formed turbidite channels filled by conglomerates, sandstones and shales. These moderately to highly efficient turbidite are intercalated to pro delta pelites and low density turbid plumes deposits, which have mostly been re mobilized as slump and debris flows (chaotic deposits). Pelites were accumulated mainly in the normal fluvial sedimentation phases, when the sandy sediment was retained next to the canyon head and were reworked by the tides on the upper part of the estuary. (author)

  18. Mapping rock forming minerals at Boundary Canyon, Death Valey National Park, California, using aerial SEBASS thermal infrared hyperspectral image data

    Science.gov (United States)

    Aslett, Zan; Taranik, James V.; Riley, Dean N.

    2018-02-01

    Aerial spatially enhanced broadband array spectrograph system (SEBASS) long-wave infrared (LWIR) hyperspectral image data were used to map the distribution of rock-forming minerals indicative of sedimentary and meta-sedimentary lithologies around Boundary Canyon, Death Valley, California, USA. Collection of data over the Boundary Canyon detachment fault (BCDF) facilitated measurement of numerous lithologies representing a contact between the relatively unmetamorphosed Grapevine Mountains allochthon and the metamorphosed core complex of the Funeral Mountains autochthon. These included quartz-rich sandstone, quartzite, conglomerate, and alluvium; muscovite-rich schist, siltstone, and slate; and carbonate-rich dolomite, limestone, and marble, ranging in age from late Precambrian to Quaternary. Hyperspectral data were reduced in dimensionality and processed to statistically identify and map unique emissivity spectra endmembers. Some minerals (e.g., quartz and muscovite) dominate multiple lithologies, resulting in a limited ability to differentiate them. Abrupt variations in image data emissivity amongst pelitic schists corresponded to amphibolite; these rocks represent gradation from greenschist- to amphibolite-metamorphic facies lithologies. Although the full potential of LWIR hyperspectral image data may not be fully utilized within this study area due to lack of measurable spectral distinction between rocks of similar bulk mineralogy, the high spectral resolution of the image data was useful in characterizing silicate- and carbonate-based sedimentary and meta-sedimentary rocks in proximity to fault contacts, as well as for interpreting some mineral mixtures.

  19. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative

  20. Environmental analysis of Lower Pueblo/Lower Los Alamos Canyon, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Becker, N.M.; Rodgers, J.C.; Hansen, W.R.

    1994-12-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, Pueblo Canyon, and Los Alamos Canyon found residual contamination at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons all the way to the Rio Grande. The largest reservoir of residual radioactivity is in lower Pueblo Canyon, which is on DOE property. However, residual radioactivity does not exceed proposed cleanup criteria in either lower Pueblo or lower Los Alamos Canyons. The three alternatives proposed are (1) to take no action, (2) to construct a sediment trap in lower Pueblo Canyon to prevent further transport of residual radioactivity onto San Ildefonso Indian Pueblo land, and (3) to clean the residual radioactivity from the canyon system. Alternative 2, to cleanup the canyon system, is rejected as a viable alternative. Thousands of truckloads of sediment would have to be removed and disposed of, and this effort is unwarranted by the low levels of contamination present. Residual radioactivity levels, under either present conditions or projected future conditions, will not result in significant radiation doses to persons exposed. Modeling efforts show that future transport activity will not result in any residual radioactivity concentrations higher than those already existing. Thus, although construction of a sediment trap in lower Pueblo Canyon is a viable alternative, this effort also is unwarranted, and the no-action alternative is the preferred alternative.

  1. Relative habitat use by the red fox (Vulpes vulpes) in Köprülü Canyon National Park, Southern Anatolia

    OpenAIRE

    Soyumert, Anil; Gürkan, Behzat

    2013-01-01

    Large carnivore mammals are one of the indicators for healthy ecosystems. Therefore, it is important to gather scientific data about carnivores for comprehensive conservation plans. Red fox is one of the carnivore species with widest distribution in Anatolia. In the present study habitat use of red fox was investigated to contribute to reduce the insufficiency of knowledge about carnivores in Turkey. Scent-station method was used to reveal relative habitat use of red fox in Köprülü Canyon Nat...

  2. Geomorphic characterization of four shelf-sourced submarine canyons along the U.S. Mid-Atlantic continental margin

    Science.gov (United States)

    Obelcz, Jeffrey; Brothers, Daniel S.; Chaytor, Jason D.; ten Brink, Uri S.; Ross, Steve W.; Brooke, Sandra

    2013-01-01

    Shelf-sourced submarine canyons are common features of continental margins and are fundamental to deep-sea sedimentary systems. Despite their geomorphic and geologic significance, relatively few passive margin shelf-breaching canyons worldwide have been mapped using modern geophysical methods. Between 2007 and 2012 a series of geophysical surveys was conducted across four major canyons of the US Mid-Atlantic margin: Wilmington, Baltimore, Washington, and Norfolk canyons. More than 5700 km2 of high-resolution multibeam bathymetry and 890 line-km of sub-bottom CHIRP profiles were collected along the outer shelf and uppermost slope (depths of 80-1200 m). The data allowed us to compare and contrast the fine-scale morphology of each canyon system. The canyons have marked differences in the morphology and orientation of canyon heads, steepness and density of sidewall gullies, and the character of the continental shelf surrounding canyon rims. Down-canyon axial profiles for Washington, Baltimore and Wilmington canyons have linear shapes, and each canyon thalweg exhibits morphological evidence for recent, relatively small-scale sediment transport. For example, Washington Canyon displays extremely steep wall gradients and contains ~100 m wide, 5–10 m deep, v-shaped incisions down the canyon axis, suggesting modern or recent sediment transport. In contrast, the convex axial thalweg profile, the absence of thalweg incision, and evidence for sediment infilling at the canyon head, suggest that depositional processes strongly influence Norfolk Canyon during the current sea-level high-stand. The north walls of Wilmington, Washington and Norfolk canyons are steeper than the south walls due to differential erosion, though the underlying cause for this asymmetry is not clear. Furthermore, we speculate that most of the geomorphic features observed within the canyons (e.g., terraces, tributary canyons, gullies, and hanging valleys) were formed during the Pleistocene, and show only

  3. On the escape of pollutants from urban street canyons

    Energy Technology Data Exchange (ETDEWEB)

    Baik, J.J.; Kim, J.J. [Kwangju Inst. of Science and Technology (Korea). Dept. of Environmental Science and Engineering

    2002-07-01

    Pollutant transport from urban street canyons is numerically investigated using a two-dimensional flow and dispersion model. The ambient wind blows perpendicular to the street and passive pollutants are released at the street level. Results from the control experiment with a street aspect ratio of 1 show that at the roof level of the street canyon, the vertical turbulent flux of pollutants is upward everywhere and the vertical flux of pollutants by mean flow is upward or downward. The horizontally integrated vertical flux of pollutants by mean flow at the roof level of the street canyon is downward and its magnitude is much smaller than that by turbulent process. These results indicate that pollutants escape from the street canyon mainly by turbulent process and that the net effect of mean flow is to make some escaped pollutants reenter the street canyon. Further experiments with different inflow turbulence intensities, inflow wind speeds, and street aspect ratio confirm the findings from the control experiment. In the case of two isolated buildings, the horizontally integrated vertical flux of pollutants by mean flow is upward due to flow separation but the other main results are the same as those from the control experiment. (author)

  4. Assessing the Importance of Cross-Stream Transport in Bedload Flux Estimates from Migrating Dunes: Colorado River, Grand Canyon National Park

    Science.gov (United States)

    Leary, K. P.; Buscombe, D.; Schmeeckle, M.; Kaplinski, M. A.

    2017-12-01

    Bedforms are ubiquitous in sand-bedded rivers, and understanding their morphodynamics is key to quantifying bedload transport. As such, mechanistic understanding of the spatiotemporal details of sand transport through and over bedforms is paramount to quantifying total sediment flux in sand-bedded river systems. However, due to the complexity of bedform field geometries and migration in natural settings, our ability to relate migration to bedload flux, and to quantify the relative role of tractive and suspended processes in their dynamics, is incomplete. Recent flume and numerical investigations indicate the potential importance of cross-stream transport, a process previously regarded as secondary and diffusive, to the three-dimensionality of bedforms and spatially variable translation and deformation rates. This research seeks to understand and quantify the importance of cross-stream transport in bedform three-dimensionality in a field setting. This work utilizes a high-resolution (0.25 m grid) data set of bedforms migrating in the channel of the Colorado River in Grand Canyon National Park. This data set comprises multi-beam sonar surveys collected at 3 different flow discharges ( 283, 566, and 1076 m3/s) along a reach of the Colorado River just upstream of the Diamond Creek USGS gage. Data were collected every 6 minutes almost continuously for 12 hours. Using bed elevation profiles (BEPs), we extract detailed bedform geometrical data (i.e. bedform height, wavelength) and spatial sediment flux data over a suite of bedforms at each flow. Coupling this spatially extensive data with a generalized Exner equation, we conduct mass balance calculations that evaluate the possibility, and potential importance, of cross-stream transport in the spatial variability of translation and deformation rates. Preliminary results suggest that intra-dune cross-stream transport can partially account for changes in the planform shape of dunes and may play an important role in spatially

  5. The effects of raking on sugar pine mortality following prescribed fire in Sequoia and Kings Canyon National Parks, California, USA

    Science.gov (United States)

    Nesmith, Jonathan C. B.; O'Hara, Kevin L.; van Mantgem, Phillip J.; de Valpine, Perry

    2010-01-01

    Prescribed fire is an important tool for fuel reduction, the control of competing vegetation, and forest restoration. The accumulated fuels associated with historical fire exclusion can cause undesirably high tree mortality rates following prescribed fires and wildfires. This is especially true for sugar pine (Pinus lambertiana Douglas), which is already negatively affected by the introduced pathogen white pine blister rust (Cronartium ribicola J.C. Fisch. ex Rabenh). We tested the efficacy of raking away fuels around the base of sugar pine to reduce mortality following prescribed fire in Sequoia and Kings Canyon national parks, California, USA. This study was conducted in three prescribed fires and included 457 trees, half of which had the fuels around their bases raked away to mineral soil to 0.5 m away from the stem. Fire effects were assessed and tree mortality was recorded for three years after prescribed fires. Overall, raking had no detectable effect on mortality: raked trees averaged 30% mortality compared to 36% for unraked trees. There was a significant effect, however, between the interaction of raking and average pre-treatment forest floor fuel depth: the predicted probability of survival of a 50 cm dbh tree was 0.94 vs. 0.96 when average pre-treatment fuel depth was 0 cm for a raked and unraked tree, respectively. When average pre-treatment forest floor fuel depth was 30 cm, the predicted probability of survival for a raked 50 cm dbh tree was 0.60 compared to only 0.07 for an unraked tree. Raking did not affect mortality when fire intensity, measured as percent crown volume scorched, was very low (0% scorch) or very high (>80% scorch), but the raking treatment significantly increased the proportion of trees that survived by 9.6% for trees that burned under moderate fire intensity (1% to 80% scorch). Raking significantly reduced the likelihood of bole charring and bark beetle activity three years post fire. Fuel depth and anticipated fire intensity need

  6. Climate Change and our National and State Park Pleasures: a First Hand View From an Undergraduate Student

    Science.gov (United States)

    Davis, L. L.; Reineke, K. A.

    2008-12-01

    The importance of water, rain and snow at ten national parks in the western US and the connection to continued enjoyment of the parks was highlighted during a 4-week field-trip general education course. Each park was used as a natural laboratory in which to learn about introductory geology, camping and hiking, to gain an appreciation of nature and to learn the importance of preserving our national parks. At each place, it turns out that water was the most important aspect; whether it was in the form of precipitation, groundwater, surface storage, streams, waterfalls or snow on the ground. Its presence or absence strongly correlated to the amount of learning and enjoyment: whether it was enjoyment from vegetation, animals, physical pleasure, or cleanliness, water made an enormous difference to our group and to the success of the trip. Of course the group had thought of this before the course began: a 19-mile hike at Big Bend Ranch State Park was only going to be possible if the springs were flowing. Before attempting our rim-to-rim hike at the Grand Canyon, we found out all we could about dehydration and hyponutremia so that we could be prepared for the hike that is unfortunately deadly at times. Camping at the parks, though, under unusually harsh conditions made all of us aware of the fragile relationship. A natural question to ask as we either sat in the heat of the Chihuahuan Desert or waited out a blizzard at Yellowstone was: How will these parks be affected and how would trips to the parks differ with global warming and future climate changes? More questions came up: How much of a change will it take to make the visits unbearable, such that attendance at parks changes? How will current national park water management affect future enjoyment? If water management at the parks is not taken more seriously (or given more funding), then the possibility of more dam breaks like the one that occurred recently near Supai will more than likely increase.

  7. The timing of sediment transport down Monterey Submarine Canyon, offshore California

    Science.gov (United States)

    Stevens, Thomas; Paull, Charles K.; Ussler, William III; McGann, Mary; Buylaert, Jan-Pieter; Lundsten, Eve M.

    2013-01-01

    While submarine canyons are the major conduits through which sediments are transported from the continents out into the deep sea, the time it takes for sediment to pass down through a submarine canyon system is poorly constrained. Here we report on the first study to couple optically stimulated luminescence (OSL) ages of quartz sand deposits and accelerator mass spectrometry 14C ages measured on benthic foraminifera to examine the timing of sediment transport through the axial channel of Monterey Submarine Canyon and Fan, offshore California. The OSL ages date the timing of sediment entry into the canyon head while the 14C ages of benthic foraminifera record the deposition of hemipelagic sediments that bound the sand horizons. We use both single-grain and small (∼2 mm area) single-aliquot regeneration approaches on vibracore samples from fining-upward sequences at various water depths to demonstrate relatively rapid, decadal-scale sand transport to at least 1.1 km depth and more variable decadal- to millennial-scale transport to a least 3.5 km depth on the fan. Significant differences between the time sand was last exposed at the canyon head (OSL age) and the timing of deposition of the sand (from 14C ages of benthic foraminifera in bracketing hemipelagic sediments) are interpreted as indicating that the sand does not pass through the entire canyon instantly in large individual events, but rather moves multiple times before emerging onto the fan. The increased spread in single-grain OSL dates with water depth provides evidence of mixing and temporary storage of sediment as it moves through the canyon system. The ages also indicate that the frequency of sediment transport events decreases with distance down the canyon channel system. The amalgamated sands near the canyon head yield OSL ages that are consistent with a sub-decadal recurrence frequency while the fining-upward sand sequences on the fan indicate that the channel is still experiencing events with a 150

  8. Hydraulics of outburst floods spilling over a steep-walled canyon: Implications for paleo-discharges on Mars

    Science.gov (United States)

    Lapotre, Mathieu; Lamb, Michael

    2013-04-01

    Canyons carved by outburst floods are common landforms on Earth and Mars. These canyons are generally found in fractured basalts and jointed sedimentary rocks. Flood-carved canyons commonly have steep headwalls and a roughly constant width, and are often thought to have formed from upstream headwall propagation due to waterfall erosion. Because morphology is readily available from satellite imagery, these canyons offer a unique opportunity to quantify the discharge of rare, catastrophic paleo-floods on Earth and Mars. However, mechanistic relationships that relate canyon size to flood discharge have yet to be developed. We propose that the width of a canyon headwall in fractured rock is set by the spatial distribution of erosion around the rim of the canyon, which is controlled by the distribution of shear stresses induced by the overflowing water as it is focused into the canyon head. We test this hypothesis by performing a series of numerical simulations of flood-water focusing using ANUGA Hydro, a 2D-depth averaged, fully turbulent, hydraulic numerical modeling suite allowing for Froude-number transitions. The numerical simulations were designed to explore five dimensionless variables: the aspect ratio of the canyon (length normalized by width), the canyon width to flood-water width ratio, the canyon width to normal-flow depth ratio, the Froude number, and the topographic gradient upstream of the canyon. Preliminary results show that flow focusing leads to increased shear stresses at the canyon head compared to the sides of the canyon for subcritical floods and higher canyon aspect ratios. This suggests that proto-canyons start growing from a topographic defect in all directions until they reach a critical length for the side walls to dry. Once this critical length is attained, canyons focus most of the flood waters into their heads, and propagate upstream only, maintaining roughly constant widths. Preliminary results suggest that canyon width may be used to

  9. The source, discharge, and chemical characteristics of selected springs, and the abundance and health of associated endemic anuran species in the Mojave network parks

    Science.gov (United States)

    Schroeder, Roy A.; Smith, Gregory A.; Martin, Peter; Flint, Alan L.; Gallegos, Elizabeth; Fisher, Robert N.; Martin, Peter; Schroeder, Roy A.

    2015-01-01

    Hydrological and biological investigations were done during 2005 and 2006 in cooperation with the U.S. National Park Service to investigate the source, discharge, and chemical characteristics of selected springs and the abundance and health of endemic anuran (frog and toad) species at Darwin Falls in Death Valley National Park, Piute Spring in Mojave National Preserve, and Fortynine Palms Oasis in Joshua Tree National Park. Discharge from the springs at these sites sustains isolated riparian habitats in the normally dry Mojave Desert. Data were collected on water quantity (discharge) and quality, air and water temperature, and abundance and health of endemic anuran species. In addition, a single survey of the abundance and health of endemic anuran species was completed at Rattlesnake Canyon in Joshua Tree National Park. Results from this study were compared to limited historical data, where they exist, and can provide a baseline for future hydrological and biological investigations to evaluate the health and sustainability of the resource and its response to changing climate and increasing human use.

  10. Partly standing internal tides in a dendritic submarine canyon observed by an ocean glider

    Science.gov (United States)

    Hall, Rob A.; Aslam, Tahmeena; Huvenne, Veerle A. I.

    2017-08-01

    An autonomous ocean glider is used to make the first direct measurements of internal tides within Whittard Canyon, a large, dendritic submarine canyon system that incises the Celtic Sea continental slope and a site of high benthic biodiversity. This is the first time a glider has been used for targeted observations of internal tides in a submarine canyon. Vertical isopycnal displacement observations at different stations fit a one-dimensional model of partly standing semidiurnal internal tides - comprised of a major, incident wave propagating up the canyon limbs and a minor wave reflected back down-canyon by steep, supercritical bathymetry near the canyon heads. The up-canyon internal tide energy flux in the primary study limb decreases from 9.2 to 2.0 kW m-1 over 28 km (a dissipation rate of 1 - 2.5 ×10-7 Wkg-1), comparable to elevated energy fluxes and internal tide driven mixing measured in other canyon systems. Within Whittard Canyon, enhanced mixing is inferred from collapsed temperature-salinity curves and weakened dissolved oxygen concentration gradients near the canyon heads. It has previously been hypothesised that internal tides impact benthic fauna through elevated near-bottom current velocities and particle resuspension. In support of this, we infer order 20 cm s-1 near-bottom current velocities in the canyon and observe high concentrations of suspended particulate matter. The glider observations are also used to estimate a 1 °C temperature range and 12 μmol kg-1 dissolved oxygen concentration range, experienced twice a day by organisms on the canyon walls, due to the presence of internal tides. This study highlights how a well-designed glider mission, incorporating a series of tide-resolving stations at key locations, can be used to understand internal tide dynamics in a region of complex topography, a sampling strategy that is applicable to continental shelves and slopes worldwide.

  11. Mammal inventories for eight National Parks in the Southern Colorado Plateau Network

    Science.gov (United States)

    Bogan, Michael A.; Geluso, Keith; Haymond, Shauna; Valdez, Ernest W.

    2007-01-01

    Historically, the Colorado Plateau has been the subject of many geological and biological explorations. J. W. Powell explored and mapped the canyon country of the Colorado River in 1869 (Powell 1961). C. H. Merriam, V. Bailey, M. Cary, and other employees of the Bureau of Biological Survey conducted biological explorations of the area in the late 1800s. In recent times, researchers such as S. D. Durrant (1952), Durrant and Robinson (1962), D. M. Armstrong (1972), J. S. Findley et al. (1975), D. F. Hoff meister (1986), and J. Fitzgerald et al. (1994) have made considerable contributions to our understanding of the fauna of the Colorado Plateau. Despite earlier efforts, biological details on many regions of the plateau have remained insufficiently explored. In an effort to gather valuable biological information, the National Park Service (NPS) initiated a nationwide program to inventory vascular plants and vertebrates on NPS lands (Stuart 2000). The U.S. Geological Survey, Fort Collins Science Center, Arid Lands Field Station became a cooperator on this effort in 2001, when we began mammalian inventories on five parks within the NPS Southern Colorado Plateau Network (SCPN): Aztec Ruins National Monument (AZRU), El Morro National Monument (ELMO), Petroglyph National Monument (PETR), Salinas Pueblo Missions National Monument (SAPU), and Yucca House National Monument (YUHO). Existing baseline data on mammalian occurrences in these parks varied from very sparse to moderate, with little information available for most parks. In most cases, information was insufficient to assess the status of species of local concern. A final report on inventory efforts on these five parks was submitted in February 2004 (Bogan et al. 2004). In 2003, biologists from the Arid Lands Field Station began work on three additional parks in the SCPN: Bandelier National Monument (BAND), Chaco Culture National Historical Park (CHCU), and El Malpaís National Monument (ELMA). The primary emphasis at

  12. The Jurassic section along McElmo Canyon in southwestern Colorado

    Science.gov (United States)

    O'Sullivan, Robert B.

    1997-01-01

    In McElmo Canyon, Jurassic rocks are 1500-1600 ft thick. Lower Jurassic rocks of the Glen Canyon Group include (in ascending order) Wingate Sandstone, Kayenta Formation and Navajo Sandstone. Middle Jurassic rocks are represented by the San Rafael Group, which includes the Entrada Sandstone and overlying Wanakah Formation. Upper Jurassic rocks comprise the Junction Creek Sandstone overlain by the Morrison Formation. The Burro Canyon Formation, generally considered to be Lower Cretaceous, may be Late Jurassic in the McElmo Canyon area and is discussed with the Jurassic. The Upper Triassic Chinle Formation in the subsurface underlies, and the Upper Cretaceous Dakota Sandstone overlies, the Jurassic section. An unconformity is present at the base of the Glen Canyon Group (J-0), at the base of the San Rafael Group (J-2), and at the base of the Junction Creek Sandstone (J-5). Another unconformity of Cretaceous age is at the base of the Dakota Sandstone. Most of the Jurassic rocks consist of fluviatile, lacustrine and eolian deposits. The basal part of the Entrada Sandstone and the Wanakah Formation may be of marginal marine origin.

  13. Event-driven sediment flux in Hueneme and Mugu submarine canyons, southern California

    Science.gov (United States)

    Xu, J. P.; Swarzenski, P.W.; Noble, M.; Li, A.-C.

    2010-01-01

    Vertical sediment fluxes and their dominant controlling processes in Hueneme and Mugu submarine canyons off south-central California were assessed using data from sediment traps and current meters on two moorings that were deployed for 6 months during the winter of 2007. The maxima of total particulate flux, which reached as high as 300+ g/m2/day in Hueneme Canyon, were recorded during winter storm events when high waves and river floods often coincided. During these winter storms, wave-induced resuspension of shelf sediment was a major source for the elevated sediment fluxes. Canyon rim morphology, rather than physical proximity to an adjacent river mouth, appeared to control the magnitude of sediment fluxes in these two submarine canyon systems. Episodic turbidity currents and internal bores enhanced sediment fluxes, particularly in the lower sediment traps positioned 30 m above the canyon floor. Lower excess 210Pb activities measured in the sediment samples collected during periods of peak total particulate flux further substantiate that reworked shelf-, rather than newly introduced river-borne, sediments supply most of the material entering these canyons during storms.

  14. Preliminary hydrogeologic assessment near Tassi and Pakoon Springs, western part of Grand Canyon-Parashant National Monument, Arizona

    Science.gov (United States)

    Truini, Margot

    2013-01-01

    Tassi and Pakoon Springs are both in the Grand Wash Trough in the western part of Grand Canyon-Parashant National Monument on the Arizona Strip. The monument is jointly managed by the National Park Service (NPS) and the Bureau of Land Management. This study was in response to NPS’s need to better understand the influence from regional increases in groundwater withdrawals near Grand Canyon-Parashant on the groundwater discharge from Tassi and Pakoon Springs. The climate of the Arizona Strip is generally semiarid to arid, and springs in the monument provide the water for the fragile ecosystems that are commonly separated by large areas of dry washes in canyons with pinyon and juniper. Available hydrogeologic data from previous investigations included water levels from the few existing wells, location information for springs, water chemistry from springs, and geologic maps. Available groundwater-elevation data from the wells and springs in the monument indicate that groundwater in the Grand Wash Trough is moving from north to south, discharging to springs and into the Colorado River. Groundwater may also be moving from east to west from Paleozoic rocks in the Grand Wash Cliffs into sedimentary deposits in the Grand Wash Trough. Finally, groundwater may be moving from the northwest in the Mesoproterozoic crystalline rocks of the Virgin Mountains into the northern part of the Grand Wash Trough. Water discharging from Tassi and Pakoon Springs has a major-ion chemistry similar to that of other springs in the western part of Grand Canyon-Parashant. Stable-isotopic signatures for oxygen-18 and hydrogen-2 are depleted in the water from both Tassi and Pakoon Springs in comparison to other springs on the Arizona Strip. Tassi Spring discharges from multiple seeps along the Wheeler Fault, and the depleted isotopic signatures suggest that water may be flowing from multiple places into Lake Mead and seems to have a higher elevation or an older climate source. Elevated water

  15. ParkIndex

    DEFF Research Database (Denmark)

    Kaczynski, Andrew T; Schipperijn, Jasper; Hipp, J Aaron

    2016-01-01

    using ArcGIS 9.3 and the Community Park Audit Tool. Four park summary variables - distance to nearest park, and the number of parks, amount of park space, and average park quality index within 1 mile were analyzed in relation to park use using logistic regression. Coefficients for significant park......, planners, and citizens to evaluate the potential for park use for a given area. Data used for developing ParkIndex were collected in 2010 in Kansas City, Missouri (KCMO). Adult study participants (n=891) reported whether they used a park within the past month, and all parks in KCMO were mapped and audited...

  16. Big Canyon Creek Ecological Restoration Strategy.

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Lynn; Richardson, Shannon

    2007-10-01

    He-yey, Nez Perce for steelhead or rainbow trout (Oncorhynchus mykiss), are a culturally and ecologically significant resource within the Big Canyon Creek watershed; they are also part of the federally listed Snake River Basin Steelhead DPS. The majority of the Big Canyon Creek drainage is considered critical habitat for that DPS as well as for the federally listed Snake River fall chinook (Oncorhynchus tshawytscha) ESU. The Nez Perce Soil and Water Conservation District (District) and the Nez Perce Tribe Department of Fisheries Resources Management-Watershed (Tribe), in an effort to support the continued existence of these and other aquatic species, have developed this document to direct funding toward priority restoration projects in priority areas for the Big Canyon Creek watershed. In order to achieve this, the District and the Tribe: (1) Developed a working group and technical team composed of managers from a variety of stakeholders within the basin; (2) Established geographically distinct sub-watershed areas called Assessment Units (AUs); (3) Created a prioritization framework for the AUs and prioritized them; and (4) Developed treatment strategies to utilize within the prioritized AUs. Assessment Units were delineated by significant shifts in sampled juvenile O. mykiss (steelhead/rainbow trout) densities, which were found to fall at fish passage barriers. The prioritization framework considered four aspects critical to determining the relative importance of performing restoration in a certain area: density of critical fish species, physical condition of the AU, water quantity, and water quality. It was established, through vigorous data analysis within these four areas, that the geographic priority areas for restoration within the Big Canyon Creek watershed are Big Canyon Creek from stream km 45.5 to the headwaters, Little Canyon from km 15 to 30, the mainstem corridors of Big Canyon (mouth to 7km) and Little Canyon (mouth to 7km). The District and the Tribe

  17. Megabenthic assemblages at the Hudson Canyon head (NW Atlantic margin): Habitat-faunal relationships

    Science.gov (United States)

    Pierdomenico, Martina; Gori, Andrea; Guida, Vincent G.; Gili, Josep-Maria

    2017-09-01

    The distribution of megabenthic communities at the head of Hudson Canyon and adjacent continental shelf was studied by means of underwater video transects and still photo imagery collected using a towed camera system. The goal was to explore the relationships between faunal distribution and physical seafloor conditions and to test the hypothesis that increased seafloor heterogeneity in the Hudson Canyon supports a larger diversity of benthic communities, compared with the adjacent continental shelf. Hierarchical cluster analysis was performed to identify benthic assemblages as defined in imagery. The BIO-ENV procedure and the Canonical Correspondence Analysis were carried out to elucidate species groupings in relation to terrain variables extracted from bathymetric data. Species accumulation curves were generated to evaluate species turn over in and out of Hudson Canyon. The results indicate that seafloor morphology is the main physical factor related to benthic community composition and distribution. Assemblages dominated by sponges, zoanthids and cup corals colonized the canyon margins and flanks, and were associated with coarse-grained sediments, while sea pen assemblages were observed along muddy seafloor within the thalweg. An assemblage dominated by sea stars occurred on the shelf, associated with a sandy seafloor. Some assemblages were exclusively observed in the canyon area, suggesting that the increased variability of seafloor composition, together with the oceanographic processes specific to the canyon area, enhance beta diversity. The colonization by benthic suspension feeders within the canyon, in contrast to shelf assemblages, mainly composed of carnivores and detritus feeders could be favored the intense hydrodynamics at the canyon head that increase the availability of suspended organic matter. From the perspective of management and conservation of marine resources, the results obtained support the relevance of Hudson Canyon as a biodiversity hotspot

  18. Marble Canyon spring sampling investigation

    International Nuclear Information System (INIS)

    McCulley, B.

    1985-10-01

    The Mississippian Leadville Limestone is the most permeable formation in the lower hydrostratigraphic unit underlying the salt beds of the Paradox Formation in Gibson Dome, Paradox Basin, Utah, which is being considered as a potential nuclear waste repository site. The closest downgradient outcrop of the Mississippian limestone is along the Colorado River in Marble Canyon, Arizona. This report describes the sampling and interpretation of springs in that area to assess the relative contribution of Gibson Dome-type Leadville Limestone ground water to that spring discharge. The high-volume (hundreds of liters per second or thousands of gallons per minute) springs discharging from fault zones in Marble Canyon are mixtures of water recharged west of the Colorado River on the Kaibab Plateau and east of the river in the Kaiparowits basin. No component of Gibson Dome-type Leadville Limestone ground water is evident in major and trace element chemistry or isotopic composition of the Marble Canyon Springs. A low-volume (0.3 liters per second or 5 gallons per minute) spring with some chemical and isotopic characteristics of Gibson Dome-type Leadville Limestone water diluted by Kaiparowits basin-type water issues from a travertine mound in the Bright Angel Shale on the Little Colorado River. However, the stable isotopic composition and bromide levels of that spring discharge, in addition to probable ground-water flow paths, contradict the dilution hypothesis

  19. 36 CFR 7.13 - Yellowstone National Park.

    Science.gov (United States)

    2010-07-01

    ... characteristics. (iv) Modifying or disabling a snowcoach's original pollution control equipment is prohibited... Loop Road from its junction with the East Entrance Road to Canyon Junction. (J) The South Canyon Rim... noon and 9 p.m. each day. (N) North Canyon Rim Drive, between noon and 9 p.m. each day. (O) Riverside...

  20. Submarine canyons represent an essential habitat network for krill hotspots in a Large Marine Ecosystem.

    Science.gov (United States)

    Santora, Jarrod A; Zeno, Ramona; Dorman, Jeffrey G; Sydeman, William J

    2018-05-15

    Submarine canyon systems are ubiquitous features of marine ecosystems, known to support high levels of biodiversity. Canyons may be important to benthic-pelagic ecosystem coupling, but their role in concentrating plankton and structuring pelagic communities is not well known. We hypothesize that at the scale of a large marine ecosystem, canyons provide a critical habitat network, which maintain energy flow and trophic interactions. We evaluate canyon characteristics relative to the distribution and abundance of krill, critically important prey in the California Current Ecosystem. Using a geological database, we conducted a census of canyon locations, evaluated their dimensions, and quantified functional relationships with krill hotspots (i.e., sites of persistently elevated abundance) derived from hydro-acoustic surveys. We found that 76% of krill hotspots occurred within and adjacent to canyons. Most krill hotspots were associated with large shelf-incising canyons. Krill hotspots and canyon dimensions displayed similar coherence as a function of latitude and indicate a potential regional habitat network. The latitudinal migration of many fish, seabirds and mammals may be enhanced by using this canyon-krill network to maintain foraging opportunities. Biogeographic assessments and predictions of krill and krill-predator distributions under climate change may be improved by accounting for canyons in habitat models.

  1. B-Plant Canyon Ventilation Control System Description; FINAL

    International Nuclear Information System (INIS)

    MCDANIEL, K.S.

    1999-01-01

    Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This document describes the CVCS system components which include a Programmable Logic Controller (PLC) coupled with an Operator Interface Unit (OIU) and application software. This document also includes an Alarm Index specifying the setpoints and technical basis for system analog and digital alarms

  2. 陕西金丝峡国家森林公园旅游环境承载力探析%Analysis on Tourism Environmental Capacity of Jinsi Canyon National Forest Park in Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    杜忠潮

    2012-01-01

    基于旅游环境承载力的概念和分析评价方法,对金丝峡国家森林公园的资源空间承载力、设施承载力、生态环境承载力,以及综合承载能力进行分析测算.结果表明,研究区最佳日游客容量为6 238人,合理的年游客容量为112.28万人次/a.金丝峡国家森林公园的现状年、日游客接待量均处于适载状态,逢“假日旅游”高峰期却会出现游客流量严重超载.针对该旅游风景区游客接待状况及其旅游业发展,提出对策性建议和措施.%Based on the concept of tourism environmental capacity and the methods of evaluation, the resource space carrying capacity, facility capacity, ecological carrying capacity, as well as the overall carrying capacity of the Jinsi Canyon National Forest Park were analyzed and measured. The results showed that the rational daily number of tourists was 6 238 and the reasonable annual capacity was 1. 122 8 million. The current daily number and annual amount of tourists of the park were in reasonable levels. The number of tourist would reach the peak during national holidays, which seriously exceeded the overall carrying capacity. In accordance with the tourist reception conditions of the tourist scenic spot, several suggestions were proposed.

  3. Rapid formation of a modern bedrock canyon by a single flood event

    Science.gov (United States)

    Lamb, Michael P.; Fonstad, Mark A.

    2010-07-01

    Deep river canyons are thought to form slowly over geological time (see, for example, ref. 1), cut by moderate flows that reoccur every few years. In contrast, some of the most spectacular canyons on Earth and Mars were probably carved rapidly during ancient megaflood events. Quantification of the flood discharge, duration and erosion mechanics that operated during such events is hampered because we lack modern analogues. Canyon Lake Gorge, Texas, was carved in 2002 during a single catastrophic flood. The event offers a rare opportunity to analyse canyon formation and test palaeo-hydraulic-reconstruction techniques under known topographic and hydraulic conditions. Here we use digital topographic models and visible/near-infrared aerial images from before and after the flood, discharge measured during the event, field measurements and sediment-transport modelling to show that the flood moved metre-sized boulders, excavated ~7m of limestone and transformed a soil-mantled valley into a bedrock canyon in just ~3days. We find that canyon morphology is strongly dependent on rock type: plucking of limestone blocks produced waterfalls, inner channels and bedrock strath terraces, whereas abrasion of cemented alluvium sculpted walls, plunge pools and streamlined islands. Canyon formation was so rapid that erosion might have been limited by the ability of the flow to transport sediment. We suggest that our results might improve hydraulic reconstructions of similar megafloods on Earth and Mars.

  4. Giant landslides and turbidity currents in the Agadir Canyon Region, NW-Africa

    Science.gov (United States)

    Krastel, Sebastian; Wynn, Russell B.; Stevenson, Christopher; Feldens, Peter; Mehringer, Lisa; Schürer, Anke

    2017-04-01

    Coring and drilling of the Moroccan Turbidite System off NW-Africa revealed a long sequence of turbidites, mostly sourced from the Moroccan continental margin and the volcanic Canary Islands. The largest individual flow deposits in the Moroccan Turbidite System contain sediment volumes >100 km3, although these large-scale events are relatively infrequent with a recurrence interval of 10,000 years (over the last 200,000 years). The largest siliciclastic flow in the last 200,000 years was the 'Bed 5 event', which transported 160 km3 of sediment up to 2000 km from the Agadir Canyon region to the southwest Madeira Abyssal Plain. While the Moroccan Turbidite System is extremely well investigated, almost no data from the source region, i.e. the Agadir Canyon, are available. Understanding why some submarine landslides remain as coherent blocks of sediment throughout their passage downslope, while others mix and disintegrate almost immediately after initial failure, is a major scientific challenge, which was addressed in the Agadir Canyon source region during RV Maria S. Merian Cruise MSM32 in late 2013. A major landslide area was identified 200 km south of the Agadir Canyon. A landslide was traced from this failure area to the Agadir Canyon. This landslide entered the canyon in about 2500 m water depth. Despite a significant increase in slope angle, the landslide did not disintegrate into a turbidity current when entering the canyon but moved on as landslide for at least another 200 km down the canyon. The age of the landslide ( 145 ka) does not correspond to any major turbidte deposit in the Moroccan Turbidite System, further supporting the fact that the landslide did not disintegrate into a major turbidity current. A core taken about 350 m above the thalweg in the head region of Agadir Canyon shows a single coarse-grained turbidite, which resembles the composition of the Bed 5 event in the Madeira Abyssal Plain. Hence, the Bed 5 turbidite originated as a failure in the

  5. Implications of tree planting on pollutant dispersion in street canyons

    NARCIS (Netherlands)

    Gromke, C.B.; Ruck, B.

    2009-01-01

    Traffic pollutant dispersion processes inside urban street canyons with avenue-like tree planting have been studied in wind tunnel experiments. Tree planting of different crown porosities and their effects on the pollutant concentrations at the canyon walls have been investigated for wind

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

    Science.gov (United States)

    2013-04-10

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group... Adaptive Management Work Group (AMWG) makes recommendations to the Secretary of the Interior concerning... Federal advisory committee, the AMWG, a technical work group, a Grand Canyon Monitoring and Research...

  7. Numerical Study of Traffic Pollutant Dispersion within Different Street Canyon Configurations

    Directory of Open Access Journals (Sweden)

    Yucong Miao

    2014-01-01

    Full Text Available The objective of this study is to numerically study flow and traffic exhaust dispersion in urban street canyons with different configurations to find out the urban-planning strategies to ease the air pollution. The Computational Fluid Dynamics (CFD model used in this study—Open Source Field Operation and Manipulation (OpenFOAM software package—was firstly validated against the wind-tunnel experiment data by using three different k-ε turbulence models. And then the patterns of flow and dispersion within three different kinds of street canyon configuration under the perpendicular approaching flow were numerically studied. The result showed that the width and height of building can dramatically affect the pollution level inside the street canyon. As the width or height of building increases, the pollution at the pedestrian level increases. And the asymmetric configuration (step-up or step-down street canyon could provide better ventilation. It is recommended to design a street canyon with nonuniform configurations. And the OpenFOAM software package can be used as a reliable tool to study flows and dispersions around buildings.

  8. Impact of aspect ratio and solar heating on street canyon air temperature

    International Nuclear Information System (INIS)

    Memon, R.A.; Lal, K.

    2011-01-01

    The results obtained from RNG (Re-Normalization Group) version of k-and turbulence model are reported in this study. The model is adopted to elucidate the impact of different building aspect ratios (i.e., ratio of building-height-to-street-canyon-width) and solar heating on temperatures in street canyon. The validation of Navier-Stokes and energy an sport equations showed that the model prediction for air-temperature and ambient wind provides reasonable accuracy. The model was applied on AR (Aspect Ratios) one to eight and surface temperature difference (delta and theta/sub s-a/)) of 2 -8. Notably, air-temperatures were higher in high AR street canyons in particular on the leeward side of the street canyon. Further investigation showed that the difference between the air-temperature 'high and low AR street canyons (AR) was positive and high with higher delta and theta/sub s-a/) conversely, the AR become negative and low gradually with lower values of delta and theta(/sub s-a/). These results could be very beneficial for the city and regional planners, civil engineers Id HVAC experts who design street canyons and strive for human thermal comfort with minimum possible energy requirements. (author)

  9. 78 FR 7810 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2013-02-04

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group... Adaptive Management Work Group (AMWG) makes recommendations to the Secretary of the Interior concerning..., the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and Research Center, and independent...

  10. 76 FR 24516 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2011-05-02

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group... Adaptive Management Work Group (AMWG) makes recommendations to the Secretary of the Interior concerning..., the AMWG, a technical work group (TWG), a Grand Canyon Monitoring and Research Center, and independent...

  11. Distributions and habitat associations of deep-water corals in Norfolk and Baltimore Canyons, Mid-Atlantic Bight, USA

    NARCIS (Netherlands)

    Brooke, S.D.; Watts, M.W.; Heil, A.D.; Rhode, M.; Mienis, F.; Duineveld, G.C.A.; Davies, A.J.; Ross, S.W.

    2017-01-01

    A multi-disciplinary study of two major submarine canyons, Baltimore Canyon and Norfolk Canyon, off the US mid-Atlantic coast focused on the ecology and biology of canyon habitats, particularly those supporting deep-sea corals. Historical data on deep-sea corals from these canyons were sparse with

  12. Using large-scale flow experiments to rehabilitate Colorado River ecosystem function in Grand Canyon: Basis for an adaptive climate-resilient strategy: Chapter 17

    Science.gov (United States)

    Melis, Theodore S.; Pine, William E.; Korman, Josh; Yard, Michael D.; Jain, Shaleen; Pulwarty, Roger S.; Miller, Kathleen; Hamlet, Alan F.; Kenney, Douglas S.; Redmond, Kelly T.

    2016-01-01

    Adaptive management of Glen Canyon Dam is improving downstream resources of the Colorado River in Glen Canyon National Recreation Area and Grand Canyon National Park. The Glen Canyon Dam Adaptive Management Program (AMP), a federal advisory committee of 25 members with diverse special interests tasked to advise the U.S. Department of the Interior), was established in 1997 in response to the 1992 Grand Canyon Protection Act. Adaptive management assumes that ecosystem responses to management policies are inherently complex and unpredictable, but that understanding and management can be improved through monitoring. Best known for its high-flow experiments intended to benefit physical and biological resources by simulating one aspect of pre-dam conditions—floods, the AMP promotes collaboration among tribal, recreation, hydropower, environmental, water and other natural resource management interests. Monitoring has shown that high flow experiments move limited new tributary sand inputs below the dam from the bottom of the Colorado River to shorelines; rebuilding eroded sandbars that support camping areas and other natural and cultural resources. Spring-timed high flows have also been shown to stimulate aquatic productivity by disturbing the river bed below the dam in Glen Canyon. Understanding about how nonnative tailwater rainbow trout (Oncorhynchus mykiss), and downstream endangered humpback chub (Gila cypha) respond to dam operations has also increased, but this learning has mostly posed “surprise” adaptation opportunities to managers. Since reoperation of the dam to Modified Low Fluctuating Flows in 1996, rainbow trout now benefit from more stable daily flows and high spring releases, but possibly at a risk to humpback chub and other native fishes downstream. In contrast, humpback chub have so far proven robust to all flows, and native fish have increased under the combination of warmer river temperatures associated with reduced storage in Lake Powell, and a

  13. H-Canyon Recovery Crawler

    Energy Technology Data Exchange (ETDEWEB)

    Kriikku, E. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hera, K. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Marzolf, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Phillips, M. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-01

    The Nuclear Material Disposition Project group asked the Savannah River National Lab (SRNL) Research and Development Engineering (R&DE) department to help procure, test, and deploy a remote crawler to recover the 2014 Inspection Crawler (IC) that tipped over in the H-Canyon Air Exhaust Tunnel. R&DE wrote a Procurement Specification for a Recovery Crawler (RC) and SRNS Procurement Department awarded the contract to Power Equipment Manufacturing Inc. (PEM). The PEM RC was based on their standard sewer inspection crawler with custom arms and forks added to the front. The arms and forks would be used to upright the 2014 Inspection Crawler. PEM delivered the RC and associated cable reel, 2014 Inspection Crawler mockup, and manuals in late April 2015. R&DE and the team tested the crawler in May of 2015 and made modifications based on test results and Savannah River Site (SRS) requirements. R&DE delivered the RC to H-Area at the end of May. The team deployed the RC on June 9, 10, and 11, 2015 in the H-Canyon Air Exhaust Tunnel. The RC struggled with some obstacles in the tunnel, but eventually made it to the IC. The team spent approximately five hours working to upright the IC and eventually got it on its wheels. The IC travelled approximately 20 feet and struggled to drive over debris on the air tunnel floor. Unfortunately the IC tripped over trying to pass this obstacle. The team decided to leave the IC in this location and inspect the tunnel with the RC. The RC passed the IC and inspected the tunnel as it travelled toward H-Canyon. The team turned the RC around when it was about 20 feet from the H-Canyon crossover tunnel. From that point, the team drove the RC past the manway towards the new sand filter and stopped approximately 20 feet from the new sand filter. The team removed the RC from the tunnel, decontaminated the RC, and stored it the manway building, 294-2H. The RC deployment confirmed the IC was not in a condition to perform useful tunnel inspections and

  14. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake Havasu...

  15. A Numerical Simulation of Traffic-Related Air Pollution Exposures in Urban Street Canyons

    Science.gov (United States)

    Liu, J.; Fu, X.; Tao, S.

    2016-12-01

    Urban street canyons are usually associated with intensive vehicle emissions. However, the high buildings successively along both sides of a street block the dispersion of traffic-generated air pollutants, which enhances human exposure and adversely affects human health. In this study, an urban scale traffic pollution dispersion model is developed with the consideration of street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. Vehicle exhausts generated from traffic flows will first disperse inside a street canyon along the micro-scale wind field (generated by computational fluid dynamics (CFD) model) and then leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing, China. We found that an increase of building height along the streets leads to higher pollution levels inside streets and lower pollution levels outside, resulting in higher domain-averaged concentrations over the area. In addition, street canyons with equal (or highly uneven) building heights on two sides of a street tend to lower the urban-scale air pollution concentrations at pedestrian level. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry in consideration of traffic demand as well as local weather pattern may significantly reduce the chances of unhealthy air being inhaled by urban residents.

  16. Draft environmental assessment: Lavender Canyon site, Utah. Nuclear Waste Policy Act (Section 112)

    International Nuclear Information System (INIS)

    1984-12-01

    In February 1983, the US Department of Energy (DOE) identified the Lavender Canyon site in Utah, as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Lavender Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received. On the basis of the evaluations contained in this draft EA, the DOE has found that the Lavender Canyon site is not disqualified under the guidelines. The site is contained in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site - the Davis Canyon site. Although the Lavender Canyon site appears to be suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. On the basis of these findings, the DOE is proposing to nominate the Davis Canyon site rather than the Lavender Canyon site as one of the five sites suitable for characterization

  17. Grain-size evolution in suspended sediment and deposits from the 2004 and 2008 controlled-flood experiments in Marble and Grand Canyons, Arizona

    Science.gov (United States)

    Draut, Amy E.; Topping, David J.; Rubin, David M.; Wright, Scott A.; Schmidt, John C.

    2010-01-01

    Since the closure of Glen Canyon Dam in 1963, the hydrology, sediment supply, and distribution and size of modern alluvial deposits in the Colorado River through Grand Canyon have changed substantially (e.g., Howard and Dolan, 1981; Johnson and Carothers, 1987; Webb et al., 1999; Rubin et al., 2002; Topping et al., 2000, 2003; Wright et al., 2005; Hazel et al., 2006). The dam has reduced the fluvial sediment supply at the upstream boundary of Grand Canyon National Park by about 95 percent. Regulation of river discharge by dam operations has important implications for the storage and redistribution of sediment in the Colorado River corridor. In the absence of natural floods, sediment is not deposited at elevations that regularly received sediment before dam closure. There has been a systemwide decrease in the size and number of subaerially exposed fluvial sand deposits since the 1960s, punctuated by episodic aggradation during the exceptional high-flow intervals in the early 1980s and by sediment input from occasional tributary floods (Beus and others, 1985; Schmidt and Graf, 1990; Kearsley et al., 1994; Schmidt et al., 2004; Wright et al., 2005; Hazel et al., 2006). Fluvial sandbars are an important component of riparian ecology that, among other functions, enclose eddy backwaters that form native-fish habitat, provide a source for eolian sand that protects some archaeological sites, and are used as campsites by thousands of river-runners annually (Rubin et al., 1990; Kearsley et al., 1994; Neal et al., 2000; Wright et al., 2005; Draut and Rubin, 2008).

  18. Passive air exchanges between building and urban canyon via openings in a single facade

    International Nuclear Information System (INIS)

    Syrios, K.; Hunt, G.R.

    2008-01-01

    The results of an experimental study examining the steady exchange of air and heat between a building and an urban canyon are presented. The focus is on the effect of the canyon aspect ratio on the airflow through openings made exclusively in one side of the building. The interaction of the external wind flow and the internal thermally-driven flow was shown to depend upon the ratio of the building height H b to the canyon width W (distance between buildings forming the canyons). The trends observed as this aspect ratio (H b /W) was varied allow for identification of canyon geometries that yield reduced or enhanced building ventilation airflow rates

  19. Formation of Sheeting Joints as a Result of Compression Parallel to Convex Surfaces, With Examples from Yosemite National Park, California

    Science.gov (United States)

    Martel, S. J.

    2008-12-01

    The formation of sheeting joints has been an outstanding problem in geology. New observations and analyses indicate that sheeting joints develop in response to a near-surface tension induced by compressive stresses parallel to a convex slope (hypothesis 1) rather than by removal of overburden by erosion, as conventionally assumed (hypothesis 2). Opening mode displacements across the joints together with the absence of mineral precipitates within the joints mean that sheeting joints open in response to a near-surface tension normal to the surface rather than a pressurized fluid. Consideration of a plot of this tensile stress as a function of depth normal to the surface reveals that a true tension must arise in the shallow subsurface if the rate of that tensile stress change with depth is positive at the surface. Static equilibrium requires this rate (derivative) to equal P22 k2 + P33 k3 - ρ g cosβ, where k2 and k3 are the principal curvatures of the surface, P22 and P33 are the respective surface- parallel normal stresses along the principal curvatures, ρ is the material density, g is gravitational acceleration, and β is the slope. This derivative will be positive and sheeting joints can open if at least one principal curvature is sufficiently convex (negative) and the surface-parallel stresses are sufficiently compressive (negative). At several sites with sheeting joints (e.g., Yosemite National Park in California), the measured topographic curvatures and the measured surface-parallel stresses of about -10 MPa combine to meet this condition. In apparent violation of hypothesis 1, sheeting joints occur locally at the bottom of Tenaya Canyon, one of the deepest glaciated, U-shaped (concave) canyons in the park. The canyon-bottom sheeting joints only occur, however, where the canyon is convex downstream, a direction that nearly coincides with direction of the most compressive stress measured in the vicinity. The most compressive stress acting along the convex

  20. Macrofaunal Patterns in and around du Couedic and Bonney Submarine Canyons, South Australia.

    Directory of Open Access Journals (Sweden)

    Kathleen E Conlan

    Full Text Available Two South Australian canyons, one shelf-incising (du Couedic and one slope-limited (Bonney were compared for macrofaunal patterns on the shelf and slope that spanned three water masses. It was hypothesized that community structure would (H1 significantly differ by water mass, (H2 show significant regional differences and (H3 differ significantly between interior and exterior of each canyon. Five hundred and thirty-one species of macrofauna ≥ 1 mm were captured at 27 stations situated in depth stratified transects inside and outside the canyons from 100 to 1500 m depth. The macrofauna showed a positive relationship to depth in abundance, biomass, species richness and community composition while taxonomic distinctness and evenness remained high at all depths. Biotic variation on the shelf was best defined by variation in bottom water primary production while sediment characteristics and bottom water oxygen, temperature and nutrients defined biotic variation at greater depth. Community structure differed significantly (p<0.01 among the three water masses (shelf-flowing South Australian current, upper slope Flinders current and lower slope Antarctic Intermediate Water (H1. Although community differences between the du Couedic and Bonney regions were marginally above significance at p = 0.05 (H2, over half of the species captured were unique to each region. This supports the evidence from fish and megafaunal distributions that the du Couedic and Bonney areas are in different bioregions. Overall, the canyon interiors were not significantly different in community composition from the exterior (H3. However, both canyons had higher abundance and/or biomass, increased species dominance, different species composition and coarser sediments near the canyon heads compared to outside the canyons at the same depth (500 m, suggestive of heightened currents within the canyons that influence community composition there. At 1000-1500 m, the canyon interiors were

  1. Cold-water coral ecosystems in Cassidaigne Canyon: An assessment of their environmental living conditions

    OpenAIRE

    Fabri, Marie-claire; Bargain, Annaelle; Pairaud, Ivane; Pedel, Laura; Taupier-letage, I.

    2017-01-01

    The Cassidaigne canyon is one of the two canyons (together with Lacaze-Duthiers) of the French Mediterranean coast in which cold-water corals have settled and formed large colonies, providing a structural habitat for other species. Nevertheless, the communities settled in the Cassidaigne canyon are physically impacted by discharges of bauxite residues. New information on the distribution of the species Madrepora oculata and the associated species diversity in Cassidaigne canyon was provid...

  2. 75 FR 34476 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2010-06-17

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group... Management Work Group. The purpose of the Adaptive Management Work Group is to advise and to provide... of the Glen Canyon Dam Adaptive Management Work Group is in the public interest in connection with...

  3. Draft environmental assessment: Davis Canyon site, Utah. Nuclear Waste Policy Act (Section 112)

    International Nuclear Information System (INIS)

    1984-12-01

    In February 1983, the US Department of Energy (DOE) identified the Davis Canyon site in Utah, as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the Davis Canyon site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received. On the basis of the evaluations reported in this draft EA, the DOE has found that the Davis Canyon site is not disqualified under the guidelines. The site is in the Paradox Basin, which is one of five distinct geohydrologic settings considered for the first repository. This setting contains one other potentially acceptable site - the Lavender Canyon site. Although the Lavender Canyon site appears to be suitable for site characterization, the DOE has concluded that the Davis Canyon site is the preferred site in the Paradox Basin. Furthermore, the DOE finds that the site is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is proposing to nominate the Davis Canyon site as one of five sites suitable for characterization. Having compared the Davis Canyon site with the other four sites proposed for nomination, the DOE has determined that the Davis Canyon site is not one of the three preferred sites for recommendation to the President as candidates for characterization

  4. Are amphitheater headed canyons indicative of a particular formative process?

    Science.gov (United States)

    Ryan, A. J.; Whipple, K. X.; Johnson, J. P.

    2012-12-01

    Tributary canyons with amphitheater-shaped heads have previously been interpreted as evidence for groundwater seepage erosion, particularly in environments where fluvial processes are assumed to be negligible. However, some have questioned whether this canyon morphology is truly diagnostic of a particular formative process. We seek to determine the relative roles of fluvial and groundwater-related processes and the strength of stratigraphic control on the Colorado Plateau through a combination of fieldwork and GIS analysis. Amphitheater valleys may have overhanging or steep-sided headwalls with a semicircular plan-view pattern. It is reasonable to assume that this form is a result of focused erosion at the base of the headwall (i.e. sapping). Two frequently cited agents may lead to undermining: plunge-pool scour at the base of waterfalls and seepage induced weathering and erosion where the groundwater table intersects the land surface. Both processes are enhanced where weaker, less permeable layers underlie stronger cap rock. We conducted preliminary fieldwork in two locations on the Colorado Plateau, where there are many classic examples of amphitheater headed canyons. The Escalante River landscape is highly variable with a range of canyon and valley-head forms, many of which cut through the thick Navajo Sandstone into the underlying shale and sand of the Kayenta Formation. Northeast of Escalante National Monument, at the base of the Henry Mountains, is Tarantula Mesa. The canyons there are also considerably variable, with nearly all containing at least one abrupt amphitheater knickpoint at the valley head or farther downstream. Our observations are presented here with an analysis of the canyon profiles, surrounding topography, and potential structural controls. We have found that nearly all amphitheaters in both locales show signs of groundwater seepage weathering and plausibly seepage erosion. However, many also contain plunge pools and evidence of substantial

  5. Effects of building roof greening on air quality in street canyons

    Science.gov (United States)

    Baik, Jong-Jin; Kwak, Kyung-Hwan; Park, Seung-Bu; Ryu, Young-Hee

    2012-12-01

    Building roof greening is a successful strategy for improving urban thermal environment. It is of theoretical interest and practical importance to study the effects of building roof greening on urban air quality in a systematic and quantitative way. In this study, we examine the effects of building roof greening on air quality in street canyons using a computational fluid dynamics (CFD) model that includes the thermodynamic energy equation and the transport equation of passive, non-reactive pollutants. For simplicity, building roof greening is represented by specified cooling. Results for a simple building configuration with a street canyon aspect ratio of one show that the cool air produced due to building roof greening flows into the street canyon, giving rise to strengthened street canyon flow. The strengthened street canyon flow enhances pollutant dispersion near the road, which decreases pollutant concentration there. Thus, building roof greening improves air quality near the road. The degree of air quality improvement near the road increases as the cooling intensity increases. In the middle region of the street canyon, the air quality can worsen when the cooling intensity is not too strong. Results for a real urban morphology also show that building roof greening improves air quality near roads. The degree of air quality improvement near roads due to building roof greening depends on the ambient wind direction. These findings provide a theoretical foundation for constructing green roofs for the purpose of improving air quality near roads or at a pedestrian level as well as urban thermal environment. Further studies using a CFD model coupled with a photochemistry model and a surface energy balance model are required to evaluate the effects of building roof greening on air quality in street canyons in a more realistic framework.

  6. Near-inertial motions in the DeSoto Canyon during Hurricane Georges

    Science.gov (United States)

    Jordi, Antoni; Wang, Dong-Ping; Hamilton, Peter

    2016-09-01

    Hurricane Georges passed directly over an array of 13 moorings deployed in the DeSoto Canyon in the northern Gulf of Mexico on 27-28 September 1998. Current velocity data from the mooring array were analyzed together with a primitive-equation model simulation with realistic hurricane forcing, to characterize the generation and propagation of the hurricane-generated near-inertial waves. The model successfully reproduces the observed mean (sub-inertial) and near-inertial motions. The upper ocean response is strongly impacted by the canyon 'wall': a strong jet is formed along the slope, and the near-inertial motions on the shelf are rapidly suppressed. The model results moreover suggest that strong near-inertial waves in the mixed layer are mostly trapped in an energy flux recirculating gyre around the canyon. This gyre retains the near-inertial energy in the canyon region and enhances the transfer of near-inertial energy below the mixed layer. Additional simulations with idealized topographies show that the presence of a steep slope rather than the canyon is fundamental for the generation of this recirculating gyre. The near-inertial wave energy budget shows that during the study period the wind generated an input of 6.79 × 10-2 Wm-2 of which about 1/3, or 2.43 × 10-2 Wm-2, was transferred below the mixed layer. The horizontal energy flux into and out of the canyon region, in contrast, was relatively weak.

  7. Bedrock Canyons Carved by the Largest Known Floods on Earth and Mars

    Science.gov (United States)

    Lamb, M. P.; Lapôtre, M. G. A.; Larsen, I. J.; Williams, R. M. E.

    2017-12-01

    The surface of Earth is a dynamic and permeable interface where the rocky crust is sculpted by ice, wind and water resulting in spectacular mountain ranges, vast depositional basins and environments that support life. These landforms and deposits contain a rich, yet incomplete, record of Earth history that we are just beginning to understand. Some of the most dramatic landforms are the huge bedrock canyons carved by catastrophic floods. On Mars, similar bedrock canyons, known as Outflow Channels, are the most important indicators of large volumes of surface water in the past. Despite their importance and now decades of observations of canyon morphology, we lack a basic understanding of how the canyons formed, which limits our ability to reconstruct flood discharge, duration and water volume. In this presentation I will summarize recent work - using mechanistic numerical models and field observations - that suggests that bedrock canyons carved by megafloods rapidly evolve to a size and shape such that boundary shear stresses just exceed that required to entrain fractured blocks of rock. The threshold shear stress constraint allows for quantitative reconstruction of the largest known floods on Earth and Mars, and implies far smaller discharges than previous methods that assume flood waters fully filled the canyons to high water marks.

  8. Submarine canyons off Madras Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.

    Submarine canyons off the coast of Madras, Tamil Nadu, India were studied during cruise of @iINS Kistna@@ as part of the IIOE programme They consist of hill-like projections and V-shaped valleys Their other features are also reported...

  9. 3D View of Grand Canyon, Arizona

    Science.gov (United States)

    2000-01-01

    The Grand Canyon is one of North America's most spectacular geologic features. Carved primarily by the Colorado River over the past six million years, the canyon sports vertical drops of 5,000 feet and spans a 445-kilometer-long stretch of Arizona desert. The strata along the steep walls of the canyon form a record of geologic time from the Paleozoic Era (250 million years ago) to the Precambrian (1.7 billion years ago).The above view was acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument aboard the Terra spacecraft. Visible and near infrared data were combined to form an image that simulates the natural colors of water and vegetation. Rock colors, however, are not accurate. The image data were combined with elevation data to produce this perspective view, with no vertical exaggeration, looking from above the South Rim up Bright Angel Canyon towards the North Rim. The light lines on the plateau at lower right are the roads around the Canyon View Information Plaza. The Bright Angel Trail, which reaches the Colorado in 11.3 kilometers, can be seen dropping into the canyon over Plateau Point at bottom center. The blue and black areas on the North Rim indicate a forest fire that was smoldering as the data were acquired on May 12, 2000.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as

  10. Influence of the Nazaré Canyon, central Portuguese margin, on late winter coccolithophore assemblages

    NARCIS (Netherlands)

    Guerreiro, C.; Sá, C.; de Stigter, H.; Oliveira, A.; Cachão, M.; Cros, L.; Borges, C.; Quaresma, L.; Santos, A.I.; Fortuño, J.-M.; Rodrigez, A.

    2014-01-01

    This paper presents a first attempt to characterize coccolithophore assemblages occurring in the context of an active submarine canyon. Coccolithophores from the upper-middle sections of the Nazaré Canyon (central Portuguese margin) – one of the largest canyons of the European continental margin –

  11. THE INFLUENCE OF BUOYANCY ON FLOW AND POLLUTANT DISPERSION IN STREET CANYONS

    OpenAIRE

    Buccolieri, Riccardo; Pulvirenti, Beatrice; Di Sabatino, Silvana; Britter, Rex

    2008-01-01

    Abstract: In this paper, the effect of buoyancy on flow and pollutant dispersion within street canyons is studied by means of computational fluid dynamics simulations. We consider a neutral boundary layer approaching a 3D street canyon assuming a wind direction perpendicular to the street canyon. The Boussinesq hypothesis for incompressible fluids is chosen for modelling buoyancy. We distinguish three cases: leeward, ground and windward wall heating. Thermal effects on both the flow ...

  12. Pollutant Concentrations in Street Canyons of Different Aspect Ratio with Avenues of Trees for Various Wind Directions

    Science.gov (United States)

    Gromke, Christof; Ruck, Bodo

    2012-07-01

    This study summarizes the effects of avenues of trees in urban street canyons on traffic pollutant dispersion. We describe various wind-tunnel experiments with different tree-avenue models in combination with variations in street-canyon aspect ratio W/ H (with W the street-canyon width and H the building height) and approaching wind direction. Compared to tree-free street canyons, in general, higher pollutant concentrations are found. Avenues of trees do not suppress canyon vortices, although the air ventilation in canyons is hindered significantly. For a perpendicular wind direction, increases in wall-average and wall-maximum concentrations at the leeward canyon wall and decreases in wall-average concentrations at the windward wall are found. For oblique and perpendicular wind directions, increases at both canyon walls are obtained. The strongest effects of avenues of trees on traffic pollutant dispersion are observed for oblique wind directions for which also the largest concentrations at the canyon walls are found. Thus, the prevailing assumption that attributes the most harmful dispersion conditions to a perpendicular wind direction does not hold for street canyons with avenues of trees. Furthermore, following dimensional analysis, an estimate of the normalized wall-maximum traffic pollutant concentration in street canyons with avenues of trees is derived.

  13. Design of a sediment-monitoring gaging network on ephemeral tributaries of the Colorado River in Glen, Marble, and Grand Canyons, Arizona

    Science.gov (United States)

    Griffiths, Ronald E.; Topping, David J.; Anderson, Robert S.; Hancock, Gregory S.; Melis, Theodore S.

    2014-01-01

    Management of sediment in rivers downstream from dams requires knowledge of both the sediment supply and downstream sediment transport. In some dam-regulated rivers, the amount of sediment supplied by easily measured major tributaries may overwhelm the amount of sediment supplied by the more difficult to measure lesser tributaries. In this first class of rivers, managers need only know the amount of sediment supplied by these major tributaries. However, in other regulated rivers, the cumulative amount of sediment supplied by the lesser tributaries may approach the total supplied by the major tributaries. The Colorado River downstream from Glen Canyon has been hypothesized to be one such river. If this is correct, then management of sediment in the Colorado River in the part of Glen Canyon National Recreation Area downstream from the dam and in Grand Canyon National Park may require knowledge of the sediment supply from all tributaries. Although two major tributaries, the Paria and Little Colorado Rivers, are well documented as the largest two suppliers of sediment to the Colorado River downstream from Glen Canyon Dam, the contributions of sediment supplied by the ephemeral lesser tributaries of the Colorado River in the lowermost Glen Canyon, and Marble and Grand Canyons are much less constrained. Previous studies have estimated amounts of sediment supplied by these tributaries ranging from very little to almost as much as the amount supplied by the Paria River. Because none of these previous studies relied on direct measurement of sediment transport in any of the ephemeral tributaries in Glen, Marble, or Grand Canyons, there may be significant errors in the magnitudes of sediment supplies estimated during these studies. To reduce the uncertainty in the sediment supply by better constraining the sediment yield of the ephemeral lesser tributaries, the U.S. Geological Survey Grand Canyon Monitoring and Research Center established eight sediment-monitoring gaging

  14. Impact of roof height non-uniformity on pollutant transport between a street canyon and intersections

    International Nuclear Information System (INIS)

    Nosek, Štěpán; Kukačka, Libor; Jurčáková, Klára; Kellnerová, Radka; Jaňour, Zbyněk

    2017-01-01

    This paper presents an extension of our previous wind-tunnel study (Nosek et al., 2016) in which we highlighted the need for investigation of the removal mechanisms of traffic pollution from all openings of a 3D street canyon. The extension represents the pollution flux (turbulent and advective) measurements at the lateral openings of three different 3D street canyons for the winds perpendicular and oblique to the along-canyon axis. The pollution was simulated by emitting a passive gas (ethane) from a homogeneous ground-level line source positioned along the centreline of the investigated street canyons. The street canyons were formed by courtyard-type buildings of two different regular urban-array models. The first model has a uniform building roof height, while the second model has a non-uniform roof height along each building's wall. The mean flow and concentration fields at the canyons' lateral openings confirm the findings of other studies that the buildings' roof-height variability at the intersections plays an important role in the dispersion of the traffic pollutants within the canyons. For the perpendicular wind, the non-uniform roof-height canyon appreciably removes or entrains the pollutant through its lateral openings, contrary to the uniform canyon, where the pollutant was removed primarily through the top. The analysis of the turbulent mass transport revealed that the coherent flow structures of the lateral momentum transport correlate with the ventilation processes at the lateral openings of all studied canyons. These flow structures coincide at the same areas and hence simultaneously transport the pollutant in opposite directions. - Highlights: • The pollutant transport strongly depends on the roof-height arrangement. • The non-uniform canyons also remove the pollutants through their lateral openings. • The higher the upstream wall, the more pollutant is removed through the top. • The lateral coherent structures correlate

  15. Effect of stable stratification on dispersion within urban street canyons: A large-eddy simulation

    Science.gov (United States)

    Li, Xian-Xiang; Britter, Rex; Norford, Leslie K.

    2016-11-01

    This study employs a validated large-eddy simulation (LES) code with high tempo-spatial resolution to investigate the effect of a stably stratified roughness sublayer (RSL) on scalar transport within an urban street canyon. The major effect of stable stratification on the flow and turbulence inside the street canyon is that the flow slows down in both streamwise and vertical directions, a stagnant area near the street level emerges, and the vertical transport of momentum is weakened. Consequently, the transfer of heat between the street canyon and overlying atmosphere also gets weaker. The pollutant emitted from the street level 'pools' within the lower street canyon, and more pollutant accumulates within the street canyon with increasing stability. Under stable stratification, the dominant mechanism for pollutant transport within the street canyon has changed from ejections (flow carries high-concentration pollutant upward) to unorganized motions (flow carries high-concentration pollutant downward), which is responsible for the much lower dispersion efficiency under stable stratifications.

  16. Aquatic macroinvertebrates and water quality in Sandia Canyon

    International Nuclear Information System (INIS)

    Bennett, K.

    1994-05-01

    In 1990, field studies of water quality and stream macroinvertebrate communities were initiated in Sandia Canyon at Los Alamos National Laboratory. The studies were designed to establish baseline data and to determine the effects of routine discharges of industrial and sanitary waste. Water quality measurements were taken and aquatic macroinvertebrates sampled at three permanent stations within the canyon. Two of the three sample stations are located where the stream regularly receives industrial and sanitary waste effluents. These stations exhibited a low diversity of macroinvertebrates and slightly degraded water quality. The last sample station, located approximately 0.4 km (0.25 mi) downstream from the nearest wastewater outfall, appears to be in a zone of recovery where water quality parameters more closely resemble those found in natural streams in the Los Alamos area. A large increase in macroinvertebrate diversity was also observed at the third station. These results indicate that effluents discharged into Sandia Canyon have a marked effect on water quality and aquatic macroinvertebrate communities

  17. Fourmile Canyon Fire Findings

    Science.gov (United States)

    Russell Graham; Mark Finney; Chuck McHugh; Jack Cohen; Dave Calkin; Rick Stratton; Larry Bradshaw; Ned Nikolov

    2012-01-01

    The Fourmile Canyon Fire burned in the fall of 2010 in the Rocky Mountain Front Range adjacent to Boulder, Colorado. The fire occurred in steep, rugged terrain, primarily on privately owned mixed ponderosa pine and Douglas-fir forests. The fire started on September 6 when the humidity of the air was very dry (¡Ö

  18. Numerical Simulation of Recent Turbidity Currents in the Monterey Canyon System, Offshore California

    Science.gov (United States)

    Heimsund, S.; Xu, J.; Nemec, W.

    2007-12-01

    The method of computational fluid dynamics (CFD) has been used, in the form of a 3D numerical model (Flow- 3D®), to perform a full-scale simulation of turbidity currents measured in December 2002 by three moorings in the Soquel and Monterey canyons. The model was verified by simulation of laboratory flows, and was upscaled to the Monterey Canyon system on the basis of high-resolution bathymetric data and flow measurements. The measured velocity profiles were sufficient to assess the flow thickness, initial velocity and duration in the canyon head zone. A computational grid with a highest feasible resolution was used, and both bathymetry and hydrostatic pressure were accounted for. The volumetric sediment concentration and exact grain- size composition of the flows were unknown, and thus a range of values for the initial concentration and bed roughness were assumed and assessed on a trial-and-error basis. The simulations reveal the behavior of a turbidity current along its descent path, including its local hydraulic characteristics (the 3D field of velocity, sediment concentration, shear stress, strain rate, and dynamic viscosity, as well as the magnitude of velocity and turbulent shear). The results confirm that the velocity structure of turbidity current is highly sensitive to variation in seafloor topography. The December 17th flow in the Soquel Canyon appears to have lost capacity by dilution over a relatively short distance and shown significant velocity fluctuations, which is attributed to the rugged topography of the canyon floor. A major loss of momentum occurred when the flow plunged at high angle into the Monterey Canyon, crashing against its bend's southern wall. The December 20th flow in the Monterey Canyon, in contrast, developed a considerably longer body and strongly accelerated towards the canyon's sharp second bend before crashing against its western wall. The mooring data show a down-canyon decline of velocity and suggest gradual waning, but the

  19. Influence of cetane improvers on the air quality in an urban street canyon

    International Nuclear Information System (INIS)

    Huang, H.; Akutsu, Y.; Arai, M.; Tamura, M.

    2000-01-01

    The concentration distributions of NO x , PM, HC and CO in an urban street canyon have been estimated using a two-dimensional air quality numerical model based on the k-e turbulent model and the atmospheric convection diffusion equation when various cetane improvers were used in diesel fuels. A wind vortex can be found within the street canyon, and the pollutants emitted from the bottom of the street canyon tend to follow the course of the wind field, moving circularly. The addition of cetane improvers can improve the air quality in a street canyon, all of the pollutants were found to decrease with increasing cetane number. (Author)

  20. Impact of roof height non-uniformity on pollutant transport between a street canyon and intersections.

    Science.gov (United States)

    Nosek, Štěpán; Kukačka, Libor; Jurčáková, Klára; Kellnerová, Radka; Jaňour, Zbyněk

    2017-08-01

    This paper presents an extension of our previous wind-tunnel study (Nosek et al., 2016) in which we highlighted the need for investigation of the removal mechanisms of traffic pollution from all openings of a 3D street canyon. The extension represents the pollution flux (turbulent and advective) measurements at the lateral openings of three different 3D street canyons for the winds perpendicular and oblique to the along-canyon axis. The pollution was simulated by emitting a passive gas (ethane) from a homogeneous ground-level line source positioned along the centreline of the investigated street canyons. The street canyons were formed by courtyard-type buildings of two different regular urban-array models. The first model has a uniform building roof height, while the second model has a non-uniform roof height along each building's wall. The mean flow and concentration fields at the canyons' lateral openings confirm the findings of other studies that the buildings' roof-height variability at the intersections plays an important role in the dispersion of the traffic pollutants within the canyons. For the perpendicular wind, the non-uniform roof-height canyon appreciably removes or entrains the pollutant through its lateral openings, contrary to the uniform canyon, where the pollutant was removed primarily through the top. The analysis of the turbulent mass transport revealed that the coherent flow structures of the lateral momentum transport correlate with the ventilation processes at the lateral openings of all studied canyons. These flow structures coincide at the same areas and hence simultaneously transport the pollutant in opposite directions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Trees in urban street canyons and their impact on the dispersion of automobile exhausts

    NARCIS (Netherlands)

    Gromke, C.B.; Ruck, B.

    2007-01-01

    The aim of the present study is to clarify the influence of trees on the dispersion of automobile exhausts in urban street canyons. For this purpose, measurements have been performed with a small scale wind tunnel model of an idealized, isolated street canyon with model trees placed along the canyon

  2. Parking Navigation for Alleviating Congestion in Multilevel Parking Facility

    OpenAIRE

    Kenmotsu, Masahiro; Sun, Weihua; Shibata, Naoki; Yasumoto, Keiichi; Ito, Minoru

    2012-01-01

    Finding a vacant parking space in a large crowded parking facility takes long time. In this paper, we propose a navigation method that minimizes the parking time based on collected real-time positional information of cars. In the proposed method, a central server in the parking facility collects the information and estimates the occupancy of each parking zone. Then, the server broadcasts the occupancy data to the cars in the parking facility. Each car then computes a parking route with the sh...

  3. Small Mammal Sampling in Mortandad and Los Alamos Canyons, 2005

    International Nuclear Information System (INIS)

    Kathy Bennett; Sherri Sherwood; Rhonda Robinson

    2006-01-01

    As part of an ongoing ecological field investigation at Los Alamos National Laboratory, a study was conducted that compared measured contaminant concentrations in sediment to population parameters for small mammals in the Mortandad Canyon watershed. Mortandad Canyon and its tributary canyons have received contaminants from multiple solid waste management units and areas of concern since establishment of the Laboratory in the 1940s. The study included three reaches within Effluent and Mortandad canyons (E-1W, M-2W, and M-3) that had a spread in the concentrations of metals and radionuclides and included locations where polychlorinated biphenyls and perchlorate had been detected. A reference location, reach LA-BKG in upper Los Alamos Canyon, was also included in the study for comparison purposes. A small mammal study was initiated to assess whether potential adverse effects were evident in Mortandad Canyon due to the presence of contaminants, designated as contaminants of potential ecological concern, in the terrestrial media. Study sites, including the reference site, were sampled in late July/early August. Species diversity and the mean daily capture rate were the highest for E-1W reach and the lowest for the reference site. Species composition among the three reaches in Mortandad was similar with very little overlap with the reference canyon. Differences in species composition and diversity were most likely due to differences in habitat. Sex ratios, body weights, and reproductive status of small mammals were also evaluated. However, small sample sizes of some species within some sites affected the analysis. Ratios of males to females by species of each site (n = 5) were tested using a Chi-square analysis. No differences were detected. Where there was sufficient sample size, body weights of adult small mammals were compared between sites. No differences in body weights were found. Reproductive status of species appears to be similar across sites. However, sample

  4. Small Mammal Sampling in Mortandad and Los Alamos Canyons, 2005

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Kathy; Sherwood, Sherri; Robinson, Rhonda

    2006-08-15

    As part of an ongoing ecological field investigation at Los Alamos National Laboratory, a study was conducted that compared measured contaminant concentrations in sediment to population parameters for small mammals in the Mortandad Canyon watershed. Mortandad Canyon and its tributary canyons have received contaminants from multiple solid waste management units and areas of concern since establishment of the Laboratory in the 1940s. The study included three reaches within Effluent and Mortandad canyons (E-1W, M-2W, and M-3) that had a spread in the concentrations of metals and radionuclides and included locations where polychlorinated biphenyls and perchlorate had been detected. A reference location, reach LA-BKG in upper Los Alamos Canyon, was also included in the study for comparison purposes. A small mammal study was initiated to assess whether potential adverse effects were evident in Mortandad Canyon due to the presence of contaminants, designated as contaminants of potential ecological concern, in the terrestrial media. Study sites, including the reference site, were sampled in late July/early August. Species diversity and the mean daily capture rate were the highest for E-1W reach and the lowest for the reference site. Species composition among the three reaches in Mortandad was similar with very little overlap with the reference canyon. Differences in species composition and diversity were most likely due to differences in habitat. Sex ratios, body weights, and reproductive status of small mammals were also evaluated. However, small sample sizes of some species within some sites affected the analysis. Ratios of males to females by species of each site (n = 5) were tested using a Chi-square analysis. No differences were detected. Where there was sufficient sample size, body weights of adult small mammals were compared between sites. No differences in body weights were found. Reproductive status of species appears to be similar across sites. However, sample

  5. Internal tides affect benthic community structure in an energetic submarine canyon off SW Taiwan

    Science.gov (United States)

    Liao, Jian-Xiang; Chen, Guan-Ming; Chiou, Ming-Da; Jan, Sen; Wei, Chih-Lin

    2017-07-01

    Submarine canyons are major conduits of terrestrial and shelf organic matter, potentially benefiting the seafloor communities in the food-deprived deep sea; however, strong bottom currents driven by internal tides and the potentially frequent turbidity currents triggered by storm surges, river flooding, and earthquakes may negatively impact the benthos. In this study, we investigated the upper Gaoping Submarine Canyon (GPSC), a high-sediment-yield canyon connected to a small mountain river (SMR) off southwest (SW) Taiwan. By contrasting the benthic meiofaunal and macrofaunal communities within and outside the GPSC, we examined how food supplies and disturbance influenced the benthic community assemblages. The benthic communities in the upper GPSC were mainly a nested subset of the adjacent slope assemblages. Several meiofaunal (e.g. ostracods) and macrofaunal taxa (e.g. peracarid crustaceans and mollusks) that typically occurred on the slope were lost from the canyon. The polychaete families switched from diverse feeding guilds on the slope to motile subsurface deposit feeders dominant in the canyon. The diminishing of epibenthic peracarids and proliferation of deep burrowing polychaetes in the GPSC resulted in macrofauna occurring largely within deeper sediment horizons in the canyon than on the slope. The densities and numbers of taxa were depressed with distinct and more variable composition in the canyon than on the adjacent slope. Both the densities and numbers of taxa were negatively influenced by internal tide flushing and positively influenced by food availability; however, the internal tides also negatively influenced the food supplies. While the meiofauna and macrofauna densities were both depressed by the extreme physical conditions in the GPSC, only the macrofaunal densities increased with depth in the canyon, presumably related to increased frequency and intensity of disturbance toward the canyon head. The population densities of meiofauna, on the

  6. Savannah River Site: Canyons and associated facilities utilization study

    International Nuclear Information System (INIS)

    Ellison, D.; Dickenson, J.

    1995-01-01

    The Westinghouse Savannah River Company was asked by the U.S. Department of Energy (DOE) to study options for utilization of Savannah River Site (SRS) Canyons and Associated Facilities to support existing and potential future material stabilization and/or disposition missions. This report is WSRC's response to that request. It includes: (1) A compilation of pending DOE material stabilization and/or disposition decisions involving utilization of SRS canyons and associated facilities, including discussion of quantities and expected availability of materials for which SRS handling and/or processing capability is a reasonable alternative under consideration. (2) A description of SRS canyons and associated facilities affected by pending DOE material stabilization and/or disposition decisions, including discussion of material handling and/or processing capabilities and capacities. (3) A comparative evaluation of three proposed scenarios for SRS canyon utilization with respect to startup and operating schedules; annual and life cycle costs; impacts on completion of commitments in the DOE Implementation Plan (IP) for Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-1; SRS ability to support alternatives under consideration in pending DOE materials stabilization and/or disposition decisions; and timing for potential transition to deactivation. (4) The sensitivity of the comparative evaluation of the three canyon utilization scenarios to the effect of the selection of other alternatives for individual stabilization missions or individual new missions. Briefings on the scope of this study have been presented to key representatives of several SRS public stakeholder groups. Briefings on the major conclusions from this study have been presented to WSRC Management, DOE-SR, EM-60, EM-1, and the DNFSB

  7. Fostering personal relationships with the wild: Oral history's role in recreation management

    Science.gov (United States)

    Alison Steiner; Daniel R. Williams

    2017-01-01

    Sequoia and Kings Canyon National Parks (SEKI) encompass much of central California's most stunning scenery. Dramatic peaks and passes, perennial snowfields, remote lake basins, alpine meadows, steep canyons, and shockingly big trees characterize the more than 800,000 acres of wild land that lie within the parks. Drought-resistant chaparral and blue oak woodlands...

  8. Thermal effects on vehicle emission dispersion in an urban street canyon

    Energy Technology Data Exchange (ETDEWEB)

    Xiaomin Xie; Zhen Huang; Jiasong Wang; Zheng Xie [Shanghai Jiao Tong Univ., School of Mechanical Engineering, Shanghai (China)

    2005-05-15

    The impact of the thermal effects on vehicle emission dispersion within street canyons is examined. The results show that heating from building wall surfaces and horizontal surfaces lead to strong buoyancy forces close to surfaces receiving direct solar radiation. This thermally induced flow is combined with mechanically induced flows formed in the canyon where there is no solar heating, and affects the transport of pollutants from the canyon to the layer aloft. The relative influence of each of these effects can be estimates by Gr/Re{sup 2}. When the windward wall is warmer than the air, an upward buoyancy flux opposes the downward advection flux along the wall; if Gr/Re{sup 2} > 2, the flow structure is divided into two counter-rotating cells, and pollutants are accumulated on the windward side of the canyon. When the horizontal surface is heated, and Gr/Re{sup 2} > 4, the flow structure is divided into two counter-rotating cells by upward buoyancy flux. Pollutants are accumulated at the windward side of the canyon. When the leeward side is heated, the buoyancy flux adds to the upward advection flux along the wall strengthening the original vortex and pollutant effects of transport compared to the isothermal case. (Author)

  9. Fault tree analysis of Project S-4404, Upgrade Canyon Exhaust System

    International Nuclear Information System (INIS)

    Browne, E.V.; Low, J.M.; Lux, C.R.

    1992-01-01

    Project S-4404, Upgrade Canyon Exhaust Systems, is a $177 million project with the purpose of upgrading the Exhaust Systems for both F and H Canyon Facilities. This upgrade will replace major portions of the F and H-Canyon exhaust systems, downstream of their respective sand filters with higher capacity and more reliable systems. Because of the high cost, DOE requested Program Control ampersand Integration (PC ampersand I) to examine specific deletions to the project. PC ampersand I requested Nuclear Processes Safety Research (NPSR) to perform an analysis to compare failure rates for the existing F ampersand H Canyon exhaust systems with the proposed exhaust system and specific proposed exhaust system alternatives. The objective of this work was to perform an analysis and compare failure rates for the existing F ampersand H Canyon exhaust systems with the proposed project exhaust system and proposed project alternatives. Based on fault tree analysis, two conclusions are made. First, D ampersand D activities can be eliminated from the project with no significant decrease to exhaust system safety. Deletion of D ampersand D activities would result in a cost savings of $29 million. Second, deletion of DOE Order 6430.1A requirements regarding DBAs would decrease exhaust system safety by a factor of 12

  10. Environmental and human impact on the sedimentary dynamic in the Rhone Delta subaquatic canyons (France-Switzerland)

    Science.gov (United States)

    Arantegui, A.; Corella, J. P.; Loizeau, J. L.; Anselmetti, F. S.; Girardclos, S.

    2012-04-01

    Deltas are very sensitive environments and highly vulnerable to variations in water discharge and the amount of suspended sediment load provided by the delta-forming currents. Human activities in the watershed, such as building of dams and irrigation ditches, or river bed deviations, may affect the discharge regime and sediment input, thus affecting delta growth. Underwater currents create deeply incised canyons cutting into the delta lobes. Understanding the sedimentary processes in these subaquatic canyons is crucial to reconstruct the fluvial evolution and human impact on deltaic environments and to carry out a geological risk assessment related to mass movements, which may affect underwater structures and civil infractructure. Recently acquired high-resolution multibeam bathymetry on the Rhone Delta in Lake Geneva (Sastre et al. 2010) revealed the complexity of the underwater morphology formed by active and inactive canyons first described by Forel (1892). In order to unravel the sedimentary processes and sedimentary evolution in these canyons, 27 sediment cores were retrieved in the distal part of each canyon and in the canyon floor/levee complex of the active canyon. Geophysical, sedimentological, geochemical and radiometric dating techniques were applied to analyse these cores. Preliminary data show that only the canyon originating at the current river mouth is active nowadays, while the others remain inactive since engineering works in the watershed occurred, confirming Sastre et al. (2010). However, alternating hemipelagic and turbiditic deposits on the easternmost canyons, evidence underflow processes during the last decades as well. Two canyons, which are located close to the Rhone river mouth, correspond to particularly interesting deeply incised crevasse channels formed when the underwater current broke through the outer bend of a meander in the proximal northern levee. In these canyons, turbidites occur in the sediment record indicating ongoing

  11. 78 FR 69302 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

    Science.gov (United States)

    2013-11-19

    ... County Great Park will be home to a world-class Olympic-style sports village and entertainment center, a... included Agua Chinon Wash, Bee Canyon Wash, Borrego Canyon Wash, and Marshburn Channel. Three of these drainages (Agua Chinon Wash, Bee Canyon Wash, and Borrego Canyon Wash) were continuations of natural washes...

  12. Evaluation of turbulence from traffic using experimental data obtained in a street canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mazzeo, N.A.; Venegas, L.E. [Univ. of Buenos Aires, Buenos Aires (Argentina). Dept. of Atmospheric and Oceanic Sciences, National Scientific and Technological Research Council

    2004-07-01

    High air pollution levels have been observed in street canyons. Within these streets, pedestrians, cyclists, drivers and residents are likely to be exposed to pollutant concentrations exceeding current air quality standards. Airflow and dispersion in street canyons are very complicated. Depending on the synoptic wind three main dispersion conditions can be identified: a) low wind conditions, b) perpendicular or near perpendicular flow for winds over 1.5-2.0 m/s blowing at an angle of more than 30 to the canyon axes, c) parallel or near parallel flow for winds over 1.5-2.0 m/s blowing from all other directions. Under condition b), airflow in canyons with H/W{approx}1 (H is the height and W is the width of the canyon) is characterised by the formation of a single vortex within the canyon. The dispersion of gaseous pollutants in a street canyon depends generally on the rate at which the street exchanges air vertically with the above roof-level atmosphere and laterally with connecting streets. There is evidence that when the synoptic wind speed is low, the mechanical traffic-produced turbulence (TPT) might place a significant role in dispersion of traffic-generated pollutants. In this paper, we analyse interactions between wind and traffic induced dispersive air motions. Data from full-scale measurements in Goettinger Strasse (Hannover, Germany) are used for application of parameterisation proposed by Di Sabatino, S. et al. (2003) and Kastner-Klein, P. et al. (2003). (orig.)

  13. Megafauna of vulnerable marine ecosystems in French mediterranean submarine canyons: Spatial distribution and anthropogenic impacts

    Science.gov (United States)

    Fabri, M.-C.; Pedel, L.; Beuck, L.; Galgani, F.; Hebbeln, D.; Freiwald, A.

    2014-06-01

    Vulnerable Marine Ecosystems (VME) in the deep Mediterranean Sea have been identified by the General Fisheries Commission for the Mediterranean as consisting of communities of Scleractinia (Lophelia pertusa and Madrepora oculata), Pennatulacea (Funiculina quadrangularis) and Alcyonacea (Isidella elongata). This paper deals with video data recorded in the heads of French Mediterranean canyons. Quantitative observations were extracted from 101 video films recorded during the MEDSEACAN cruise in 2009 (Aamp/Comex). Qualitative information was extracted from four other cruises (two Marum/Comex cruises in 2009 and 2011 and two Ifremer cruises in 1995 and 2010) to support the previous observations in the Cassidaigne and Lacaze-Duthiers canyons. All the species, fishing impacts and litter recognized in the video films recorded from 180 to 700 m depth were mapped using GIS. The abundances and distributions of benthic fishing resources (marketable fishes, Aristeidae, Octopodidae), Vulnerable Marine Species, trawling scars and litter of 17 canyons were calculated and compared, as was the open slope between the Stoechades and Toulon canyons. Funiculina quadrangularis was rarely observed, being confined for the most part to the Marti canyon and, I. elongata was abundant in three canyons (Bourcart, Marti, Petit-Rhône). These two cnidarians were encountered in relatively low abundances, and it may be that they have been swept away by repeated trawling. The Lacaze-Duthiers and Cassidaigne canyons comprised the highest densities and largest colony sizes of scleractinian cold-water corals, whose distribution was mapped in detail. These colonies were often seen to be entangled in fishing lines. The alcyonacean Callogorgia verticillata was observed to be highly abundant in the Bourcart canyon and less abundant in several other canyons. This alcyonacean was also severely affected by bottom fishing gears and is proposed as a Vulnerable Marine Species. Our studies on anthropogenic

  14. BLANCO MOUNTAIN AND BLACK CANYON ROADLESS AREAS, CALIFORNIA.

    Science.gov (United States)

    Diggles, Michael F.; Rains, Richard L.

    1984-01-01

    The mineral survey of the Blanco Mountain and Black Canyon Roadless Areas, California indicated that areas of probable and substantiated mineral-resource potential exist only in the Black Canyon Roadless Area. Gold with moderate amounts of lead, silver, zinc, and tungsten, occurs in vein deposits and in tactite. The nature of the geological terrain indicates little likelihood for the occurrence of energy resources in the roadless areas. Detailed geologic mapping might better define the extent of gold mineralization. Detailed stream-sediment sampling and analysis of heavy-mineral concentrations could better define tungsten resource potential.

  15. Lightning protection for the process canyons at the Savannah River site

    International Nuclear Information System (INIS)

    McAfee, D.E.

    1995-01-01

    Westinghouse Savannah River Company (WSRC) has performed Lightning Studies for the existing Process Canyons at the Savannah River Site (SRS). These studies were initiated to verify the lightning protection systems for the facilities and to compare the installations to the National Fire Protection (NFPA) Standard 780, Lighting Protection Code, 1992. The original study of the F-Canyon was initiated to develop answers to concerns raised by the Defense Nuclear Facility Safety Board (DNFSB). Once this study was completed it was determined that a similar study for H-Canyon would be prudent; followed by an evaluation of the Defense Waste Processing Facility (DWPF) Vitrification Building (S-Canyon). This paper will provide an overview of the nature of lightning and the principals of lightning protection. This will provide the reader with a basic understanding of the phenomena of lighting and its potential for damaging structures, components, and injuring personnel in or near the structure

  16. Complementary Research on Student Geoscience Learning at Grand Canyon by Means of In-situ and Virtual Modalities

    Science.gov (United States)

    Semken, S. C.; Ruberto, T.; Mead, C.; Bruce, G.; Buxner, S.; Anbar, A. D.

    2016-12-01

    Education through exploration—typically in the field—is fundamental in geoscience. But not all students enjoy equal access to field-based learning, while technological advances afford ever more immersive, rich, and student-centered virtual field experiences. No virtual modalities yet conceived can supplant field-based learning, but logistical and financial contraints can render them the only practical option for enabling most students to explore pedagogically powerful but inaccessible places located across and even beyond Earth. We are producers of a growing portfolio of immersive virtual field trips (iVFTs) situated around the globe, and engaged in research on iVFT effectiveness. Our methods are more complementary than comparative, given that virtual and in-situ modalities have distinct advantages and disadvantages. In the case of iVFTs, these factors have not yet been well-studied. We conducted a mixed-methods complementary study in an introductory historical-geology class (n = 120) populated mostly by non-majors and representing the diversity of our large urban Southwestern research university. For the same course credit, students chose either an in-person field trip (ipFT) to Grand Canyon National Park (control group) or an online Grand Canyon iVFT (experimental group) to be done in the same time interval. We collected quantitative and qualitative data from both groups before, during, and after both interventions. Learning outcomes based on content elements of the Trail of Time Exhibition at Grand Canyon were assessed using pre/post concept sketching and formative inquiry exercises. Student attitudes and novelty-space factors were assessed pre- and post-intervention using the PANAS instrument of Watson and Clark and with questionnaires tailored to each modality. Coding and comparison of pre/post concept sketches showed improved conceptual knowledge in both groups, but more so in the experimental (iVFT) group. Emergent themes from the pre/post questionnaires

  17. Geology and geomorphology of the Lower Deschutes River Canyon, Oregon.

    Science.gov (United States)

    Robin A. Beebee; Jim E. O' Connor; Gordon E. Grant

    2002-01-01

    This field guide is designed for geologists floating the approximately 80 kilometers (50 miles) of the Deschutes River from the Pelton-Round Butte Dam Complex west of Madras to Maupin, Oregon. The first section of the guide is a geologic timeline tracing the formation of the units that compose the canyon walls and the incision of the present canyon. The second section...

  18. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-05-06

    Various methods and systems are provided for smart parking barriers. In one example, among others, a smart parking barrier system includes a movable parking barrier located at one end of a parking space, a barrier drive configured to control positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking space and a second position that allows access to the parking space. The parking controller can initiate movement of the movable parking barrier in response to a positive identification of an individual allowed to use the parking space. The parking controller can identify the individual through, e.g., a RFID tag, a mobile device (e.g., a remote control, smartphone, tablet, etc.), an access card, biometric information, or other appropriate identifier.

  19. Environmental analysis of Acid/middle Pueblo Canyon, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Hansen, W.R.

    1982-08-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, and Pueblo Canyon found residual radioactivity at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons, all the way to the Rio Grande. The largest reservoir of radioactive material is in lower Pueblo Canyon, which is on DOE property. The only areas where residual radioactivity exceeds the proposed cleanup criteria are at the former vehicle decontamination facility, located between the former treatment plant site and Acid Canyon, around the former untreated waste outfall and for a short distance below, and in two small areas farther down in Acid Canyon. The three alternatives proposed are (1) to take no action, (2) to fence the areas where the residual radioactivity exceeds the proposed criteria (minimal action), and (3) to clean up the former vehicle decontamination facility and around the former untreated waste outfall. Calculations based on actual measurements indicate that the annual dose at the location having the greatest residual radioactivity would be about 12% of the applicable guideline. Most doses are much smaller than that. No environmental impacts are associated with either the no-action or minimal action alternatives. The impact associated with the cleanup alternative is very small. The preferred alternative is to clean up the areas around the former vehicle decontamination facility and the untreated waste outfall. This course of action is recommended not because of any real danger associated with the residual radioactivity, but rather because the cleanup operation is a minor effort and would conform with the ALARA (as low as reasonably achievable) philosophy

  20. Environmental analysis of Acid/middle Pueblo Canyon, Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ferenbaugh, R.W.; Buhl, T.E.; Stoker, A.K.; Hansen, W.R.

    1982-08-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, and Pueblo Canyon found residual radioactivity at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons, all the way to the Rio Grande. The largest reservoir of radioactive material is in lower Pueblo Canyon, which is on DOE property. The only areas where residual radioactivity exceeds the proposed cleanup criteria are at the former vehicle decontamination facility, located between the former treatment plant site and Acid Canyon, around the former untreated waste outfall and for a short distance below, and in two small areas farther down in Acid Canyon. The three alternatives proposed are (1) to take no action, (2) to fence the areas where the residual radioactivity exceeds the proposed criteria (minimal action), and (3) to clean up the former vehicle decontamination facility and around the former untreated waste outfall. Calculations based on actual measurements indicate that the annual dose at the location having the greatest residual radioactivity would be about 12% of the applicable guideline. Most doses are much smaller than that. No environmental impacts are associated with either the no-action or minimal action alternatives. The impact associated with the cleanup alternative is very small. The preferred alternative is to clean up the areas around the former vehicle decontamination facility and the untreated waste outfall. This course of action is recommended not because of any real danger associated with the residual radioactivity, but rather because the cleanup operation is a minor effort and would conform with the ALARA (as low as reasonably achievable) philosophy.

  1. Morphology and sediment dynamics of the Capbreton canyon (Bay of Biscay, SW France)

    Science.gov (United States)

    Gaudin, M.; Umr 5805; Ifremer Team

    2003-04-01

    The Canyon of Capbreton extending in the Bay of Biscay (SW France) is the deepest canyon in the world. Its structure and morphology was studied using new multibeam bathymetry, acoustic imagery and high-resolution seismic data. The canyon head appears only 250 m away from the coast line and runs westward parallel to the north coast of Spain for 160 km due to structural control, then turns northward, widens and abruptly disappears in the continental rise by 3500 m water depth. Its northern margin is flat and progrades clearly westward. Conversely the southern margin is steep and progrades towards the north (i.e. towards the canyon). Down to 800 m water depth, the canyon deeply incises the continental shelf and the axial channel is meandering (sinuosity of 1.9). The canyon shows both major and minor stream beds, perched tributary valleys, nested terraces and abandoned meanders. The terraces have three morphologies: (1) flat, (2) with a raised side or (3) with a horseshoe structure. These morphologies have been interpreted as overbank deposits or nested levees (1 and 2) or as the result of meander abandon (3). Terraces of types (1) and (2) contain mainly fine deposits resulting from decantation of the top of turbulent surges that flow in the canyon. Westward (800 to 2000 m water depth) the main talweg remains sinuous (1.7). On the southern margin, several straight or slightly sinuous S-N tributary valleys are followed by alignments of pockmarks that also indicate a structural control. On the northern margin, a single large tributary valley with a sinuous central talweg, flowing from the upper Aquitaine continental slope, is interpreted as a giant slump scar due to sediment instability. This valley is bordered to the west by a topographic high with sediment waves on the external flank that might be interpreted as a sedimentary levee. The canyon recorded a recent turbidite activity. An 18 cm-thick turbidite was deposited at 650 m water depth by a turbidity current

  2. Safety Evaluation for Packaging (onsite) T Plant Canyon Items

    International Nuclear Information System (INIS)

    OBRIEN, J.H.

    2000-01-01

    This safety evaluation for packaging (SEP) evaluates and documents the ability to safely ship mostly unique inventories of miscellaneous T Plant canyon waste items (T-P Items) encountered during the canyon deck clean off campaign. In addition, this SEP addresses contaminated items and material that may be shipped in a strong tight package (STP). The shipments meet the criteria for onsite shipments as specified by Fluor Hanford in HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments

  3. Safety Evaluation for Packaging (onsite) T Plant Canyon Items

    Energy Technology Data Exchange (ETDEWEB)

    OBRIEN, J.H.

    2000-07-14

    This safety evaluation for packaging (SEP) evaluates and documents the ability to safely ship mostly unique inventories of miscellaneous T Plant canyon waste items (T-P Items) encountered during the canyon deck clean off campaign. In addition, this SEP addresses contaminated items and material that may be shipped in a strong tight package (STP). The shipments meet the criteria for onsite shipments as specified by Fluor Hanford in HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments.

  4. Data Quality Objectives Summary Report for the 221-U Canyon Disposition Alternatives

    International Nuclear Information System (INIS)

    Miller, M.S.; Oaces, L.E.; Baxter, J.; Brown, T.M.; Enoke, D.E.; Carlson, D.; Rugg, J.E.

    1997-08-01

    The 221-U Canyon Disposition Alternatives Data Quality Objective (DQO) Process identifies the sampling and analytical requirements necessary to support future detailed evaluation of alternatives via the CERCLA process, for final disposition of the 221-U Canyon Facility. Viable alternatives for the disposition of the 221-U Facility have been identified in a CERCLA Phase I Feasibility Study (FS) (DOE-RL 1997) for the Canyon Disposition Initiative (CDI). The scope of this DQO Process is limited to the 221-U Process Canyon Building and equipment contained within the facility. Associated stacks, filters, solvent handling, vaults, and storage facilities external to the 221-U Building are not addressed in this DQO. This DQO focuses on the 221-U Building because it provides the greatest potential source of contaminant volumes and concentrations and the physical structure poses the greatest challenge for disposition decisions

  5. On the pollutant removal, dispersion, and entrainment over two-dimensional idealized street canyons

    Science.gov (United States)

    Liu, Chun-Ho; Wong, Colman C. C.

    2014-01-01

    Pollutant dispersion over urban areas is not that well understood, in particular at the street canyon scale. This study is therefore conceived to examine how urban morphology modifies the pollutant removal, dispersion, and entrainment over urban areas. An idealized computational domain consisting of 12 two-dimensional (2D) identical street canyons of unity aspect ratio is employed. The large-eddy simulation (LES) is used to calculate the turbulent flows and pollutant transport in the urban boundary layer (UBL). An area source of uniform pollutant concentration is applied on the ground of the first street canyon. A close examination on the roof-level turbulence reveals patches of low-speed air masses in the streamwise flows and narrow high-speed downdrafts in the shear layer. Different from the flows over a smooth surface, the turbulence intensities are peaked near the top of the building roughness. The pollutant is rather uniformly distributed inside a street canyon but disperses quickly in the UBL over the buildings. Partitioning the vertical pollutant flux into its mean and turbulent components demystifies that the pollutant removal is mainly governed by turbulence. Whereas, mean wind carries pollutant into and out of a street canyon simultaneously. In addition to wind speed promotion, turbulent mixing is thus required to dilute the ground-level pollutants, which are then removed from the street canyon to the UBL. Atmospheric flows slow down rapidly after the leeward buildings, leading to updrafts carrying pollutants away from the street canyons (the basic pollutant removal mechanism).

  6. Bell Canyon test summary report

    International Nuclear Information System (INIS)

    Christensen, C.L.; Peterson, E.W.

    1981-04-01

    The Bell Canyon Test was an in situ evaluation of the ability of a cement grout plug to seal boreholes. It consisted of a 2-m-long, 20-cm-diameter grout plug in an anhydrite formation at a depth of 1370 m, directly above an aquifer that provided a 12.4 MPa (1800 psi) differential pressure. The aquifer had a production capability of 38,000 l/day (240 bbl/day, 10 4 gal/day). The observed leakage after plug installation was 0.6 l/day, which is equivalent to a 50 microdarcy flow path assuming all flow occurred through the plug cross-sectional area. Laboratory results and analysis of field data indicate that the bulk of the flow occurred through a microstructure at the interface between the plug and the host rock. The Bell Canyon Test demonstrated that a plug could be formulated, emplaced, and tested under actual conditions and provide acceptable performance. When these results are related to the WIPP performance assessment models, they provide additional confidence that borehole plugging can be accomplished satisfactorily. The Bell Canyon results can also be used as basis for future activities in the generic repository sealing program for similar emplacements and performance assessment evaluations. If the observed leakage rates are not acceptable at other sites, the BCT results would indicate that the first step in improving such emplacements should deal with improved bonding of the plug to the rock at these sites. The results obtained from the BCT, when coupled with results from long-term durability assessments, form a plug performance data basis for repository designers at other proposed waste repository sites

  7. Thermal bioclimate in idealized urban street canyons in Campinas, Brazil

    Science.gov (United States)

    Abreu-Harbich, Loyde V.; Labaki, Lucila C.; Matzarakis, Andreas

    2014-01-01

    Among several urban design parameters, the height-to-width ratio (H/W) and orientation are important parameters strongly affecting thermal conditions in cities. This paper quantifies changes in thermal comfort due to typical urban canyon configurations in Campinas, Brazil, and presents urban guidelines concerning H/W ratios and green spaces to adapt urban climate change. The study focuses on thermal comfort issues of humans in urban areas and performs evaluation in terms of physiologically equivalent temperature (PET), based on long-term data. Meteorological data of air temperature, relative humidity, wind speed and solar radiation over a 7-year period (2003-2010) were used. A 3D street canyon model was designed with RayMan Pro software to simulate the influence of urban configuration on urban thermal climate. The following configurations and setups were used. The model canyon was 500 m in length, with widths 9, 21, and 44 m. Its height varied in steps of 2.5 m, from 5 to 40 m. The canyon could be rotated in steps of 15°. The results show that urban design parameters such as width, height, and orientation modify thermal conditions within street canyons. A northeast-southwest orientation can reduce PET during daytime more than other scenarios. Forestry management and green areas are recommended to promote shade on pedestrian areas and on façades, and to improve bioclimate thermal stress, in particular for H/W ratio less than 0.5. The method and results can be applied by architects and urban planners interested in developing responsive guidelines for urban climate issues.

  8. 75 FR 27550 - Electrical Interconnection of the Juniper Canyon I Wind Project

    Science.gov (United States)

    2010-05-17

    ... DEPARTMENT OF ENERGY Bonneville Power Administration Electrical Interconnection of the Juniper Canyon I Wind Project AGENCY: Bonneville Power Administration (BPA), Department of Energy (DOE). ACTION... would be generated from their proposed Juniper Canyon I Wind Energy Project (Wind Project) in Klickitat...

  9. Numerical modeling of the late Cenozoic geomorphic evolution of Grand Canyon, Arizona

    Science.gov (United States)

    Pelletier, J. D.

    2008-12-01

    The late Cenozoic geomorphic evolution of Grand Canyon has been influenced by three primary tectonic and drainage adjustment events. First, incision into the Paleozoic strata of the southwestern margin of the Colorado Plateau began at 16 Ma in response to relief production along the Grand Wash Fault. Second, the ancestral Upper Colorado River reversed drainage and became integrated with the Lower Colorado River basin through Grand Canyon between 5.5 and 6 Ma. Third, the Colorado River was influenced by Plio- Quaternary normal faulting along the Hurricane and Toroweap Faults. Despite the relatively firm constraints available on the timing of these events, the geomorphic evolution of Grand Canyon is still not well constrained and many questions remain. For example, was there a deeply-incised gorge in western Grand Canyon before Colorado River integration? How and where was the Colorado River integrated? How have incision rates varied in space and time? In this paper, I describe the results of a numerical modeling study designed to address these questions. The model integrates the stream power model for bedrock channel erosion with cliff retreat and the flexural-isostatic response to erosion. The model honors the structural geology of the Grand Canyon region, including the variable erodibility of rocks in the Colorado Plateau and the occurrence of Plio-Quaternary normal faulting along the Hurricane-Toroweap Fault system. We present the results of two models designed to bracket the possible drainage architectures of the southwestern margin of the Colorado Plateau in Miocene time. In the first model, we assume a 13,000 km2 drainage basin primarily sourced from the Hualapai and Coconino Plateaux. The results of this model indicate that relief production along the Grand Wash fault initiated the formation of a large (700 m) knickpoint that migrated headward at a rate of 15 km/Myr prior to drainage integration at 6 Ma to form a deep gorge in western Grand Canyon. This model

  10. Diablo Canyon plant information management system and integrated communication system

    International Nuclear Information System (INIS)

    Stanley, J.W.; Groff, C.

    1990-01-01

    The implementation of a comprehensive maintenance system called the plant information management system (PIMS) at the Diablo Canyon plant, together with its associated integrated communication system (ICS), is widely regarded as the most comprehensive undertaking of its kind in the nuclear industry. This paper provides an overview of the program at Diablo Canyon, an evaluation of system benefits, and highlights the future course of PIMS

  11. Diablo Canyon plant information management system and integrated communication system

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, J.W.; Groff, C.

    1990-06-01

    The implementation of a comprehensive maintenance system called the plant information management system (PIMS) at the Diablo Canyon plant, together with its associated integrated communication system (ICS), is widely regarded as the most comprehensive undertaking of its kind in the nuclear industry. This paper provides an overview of the program at Diablo Canyon, an evaluation of system benefits, and highlights the future course of PIMS.

  12. Bioavailability of sinking organic matter in the Blanes canyon and the adjacent open slope (NW Mediterranean Sea)

    Science.gov (United States)

    Lopez-Fernandez, P.; Bianchelli, S.; Pusceddu, A.; Calafat, A.; Sanchez-Vidal, A.; Danovaro, R.

    2013-05-01

    Submarine canyons are sites of intense energy and material exchange between the shelf and the deep adjacent basins. To test the hypothesis that active submarine canyons represent preferential conduits of available food for the deep-sea benthos, two mooring lines were deployed at 1200 m depth from November 2008 to November 2009 inside the Blanes canyon and on the adjacent open slope (Catalan Margin, NW Mediterranean Sea). We investigated the fluxes, biochemical composition and food quality of sinking organic carbon (OC). OC fluxes in the canyon and the open slope varied among sampling periods, though not consistently in the two sites. In particular, while in the open slope the highest OC fluxes were observed in August 2009, in the canyon the highest OC fluxes occurred in April-May 2009. For almost the entire study period, the OC fluxes in the canyon were significantly higher than those in the open slope, whereas OC contents of sinking particles collected in the open slope were consistently higher than those in the canyon. This result confirms that submarine canyons are effective conveyors of OC to the deep sea. Particles transferred to the deep sea floor through the canyons are predominantly of inorganic origin, significantly higher than that reaching the open slope at a similar water depth. Using multivariate statistical tests, two major clusters of sampling periods were identified: one in the canyon that grouped trap samples collected in December 2008, concurrently with the occurrence of a major storm at the sea surface, and associated with increased fluxes of nutritionally available particles from the upper shelf. Another cluster grouped samples from both the canyon and the open slope collected in March 2009, concurrently with the occurrence of the seasonal phytoplankton bloom at the sea surface, and associated with increased fluxes of total phytopigments. Our results confirm the key ecological role of submarine canyons for the functioning of deep-sea ecosystems

  13. Earthquakes drive large-scale submarine canyon development and sediment supply to deep-ocean basins.

    Science.gov (United States)

    Mountjoy, Joshu J; Howarth, Jamie D; Orpin, Alan R; Barnes, Philip M; Bowden, David A; Rowden, Ashley A; Schimel, Alexandre C G; Holden, Caroline; Horgan, Huw J; Nodder, Scott D; Patton, Jason R; Lamarche, Geoffroy; Gerstenberger, Matthew; Micallef, Aaron; Pallentin, Arne; Kane, Tim

    2018-03-01

    Although the global flux of sediment and carbon from land to the coastal ocean is well known, the volume of material that reaches the deep ocean-the ultimate sink-and the mechanisms by which it is transferred are poorly documented. Using a globally unique data set of repeat seafloor measurements and samples, we show that the moment magnitude ( M w ) 7.8 November 2016 Kaikōura earthquake (New Zealand) triggered widespread landslides in a submarine canyon, causing a powerful "canyon flushing" event and turbidity current that traveled >680 km along one of the world's longest deep-sea channels. These observations provide the first quantification of seafloor landscape change and large-scale sediment transport associated with an earthquake-triggered full canyon flushing event. The calculated interevent time of ~140 years indicates a canyon incision rate of 40 mm year -1 , substantially higher than that of most terrestrial rivers, while synchronously transferring large volumes of sediment [850 metric megatons (Mt)] and organic carbon (7 Mt) to the deep ocean. These observations demonstrate that earthquake-triggered canyon flushing is a primary driver of submarine canyon development and material transfer from active continental margins to the deep ocean.

  14. Study of line source characteristics for 2-D physical modelling of pollutant dispersion in street canyons

    Energy Technology Data Exchange (ETDEWEB)

    Meroney, Robert N. [Fluid Mechanics and Wind Engineering Program, Civil Engineering Department, Colorado State University Fort Collins, CO (United States); Pavageau, Michel; Rafailidis, Stilianos; Schatzmann, Michael [Meteorologisches Institut, Universitaet Hamburg, Hamburg (Germany)

    1996-08-01

    The University of Hamburg initiated a wind tunnel study of car exhaust dispersion from street canyons in an urban environment to investigate how pollution dispersion is affected by street geometry. Particular emphasis at the beginning of this work was put on the design of a line source to represent traffic exhaust. Pollution dispersion was studied in two dimensions (i.e., infinite-length streets were assumed). The case of an isolated street canyon in open country was examined first. The same street canyon geometry was subsequently studied in an urban environment, i.e., with additional canyons of similar geometry upstream and downstream of the test street. The dynamic and dispersion characteristics of the flow in the two cases were quite different. In the canyon amidst open country we observed better canyon ventilation than in the urban roughness case

  15. Review of the Diablo Canyon probabilistic risk assessment

    International Nuclear Information System (INIS)

    Bozoki, G.E.; Fitzpatrick, R.G.; Bohn, M.P.; Sabek, M.G.; Ravindra, M.K.; Johnson, J.J.

    1994-08-01

    This report details the review of the Diablo Canyon Probabilistic Risk Assessment (DCPRA). The study was performed under contract from the Probabilistic Risk Analysis Branch, Office of Nuclear Reactor Research, USNRC by Brookhaven National Laboratory. The DCPRA is a full scope Level I effort and although the review touched on all aspects of the PRA, the internal events and seismic events received the vast majority of the review effort. The report includes a number of independent systems analyses sensitivity studies, importance analyses as well as conclusions on the adequacy of the DCPRA for use in the Diablo Canyon Long Term Seismic Program

  16. Feral Cattle in the White Rock Canyon Reserve at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hathcock, Charles D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hansen, Leslie A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-03-27

    At the request of the Los Alamos Field Office (the Field Office), Los Alamos National Security (LANS) biologists placed remote-triggered wildlife cameras in and around the mouth of Ancho Canyon in the White Rock Canyon Reserve (the Reserve) to monitor use by feral cattle. The cameras were placed in October 2012 and retrieved in January 2013. Two cameras were placed upstream in Ancho Canyon away from the Rio Grande along the perennial flows from Ancho Springs, two cameras were placed at the north side of the mouth to Ancho Canyon along the Rio Grande, and two cameras were placed at the south side of the mouth to Ancho Canyon along the Rio Grande. The cameras recorded three different individual feral cows using this area as well as a variety of local native wildlife. This report details our results and issues associated with feral cattle in the Reserve. Feral cattle pose significant risks to human safety, impact cultural and biological resources, and affect the environmental integrity of the Reserve. Regional stakeholders have communicated to the Field Office that they support feral cattle removal.

  17. Sediment transport along the Cap de Creus Canyon flank during a mild, wet winter

    Directory of Open Access Journals (Sweden)

    J. Martín

    2013-05-01

    Full Text Available Cap de Creus Canyon (CCC is known as a preferential conduit for particulate matter leaving the Gulf of Lion continental shelf towards the slope and the basin, particularly in winter when storms and dense shelf water cascading coalesce to enhance the seaward export of shelf waters. During the CASCADE (CAscading, Storm, Convection, Advection and Downwelling Events cruise in March 2011, deployments of recording instruments within the canyon and vertical profiling of the water column properties were conducted to study with high spatial-temporal resolution the impact of such processes on particulate matter fluxes. In the context of the mild and wet 2010–2011 winter, no remarkable dense shelf water formation was observed. On the other hand, the experimental setup allowed for the study of the impact of E-SE storms on the hydrographical structure and the particulate matter fluxes in the CCC. The most remarkable feature in terms of sediment transport was a period of dominant E-SE winds from 12 to 16 March, including two moderate storms (maximum significant wave heights = 4.1–4.6 m. During this period, a plume of freshened, relatively cold and turbid water flowed at high speeds along the southern flank of the CCC in an approximate depth range of 150–350 m. The density of this water mass was lighter than the ambient water in the canyon, indicating that it did not cascade off-shelf and that it merely downwelled into the canyon forced by the strong cyclonic circulation induced over the shelf during the storms and by the subsequent accumulation of seawater along the coast. Suspended sediment load in this turbid intrusion recorded along the southern canyon flank oscillated between 10 and 50 mg L−1, and maximum currents speeds reached values up to 90 cm s−1. A rough estimation of 105 tons of sediment was transported through the canyon along its southern wall during a 3-day-long period of storm-induced downwelling. Following the veering of the wind

  18. The impact of traffic-flow patterns on air quality in urban street canyons

    International Nuclear Information System (INIS)

    Thaker, Prashant; Gokhale, Sharad

    2016-01-01

    We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17–42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion. - Highlights: • CFD is used to study impact of traffic-flow patterns on urban air quality. • Facilitating free-flow patterns induce more turbulence in street canyons. • Traffic-generated turbulence alters pollutant levels in urban street canyons. - This study investigates the effect of vehicle-induced-turbulence generated during free-flow traffic pattern in reduction of air pollutant concentrations in urban street canyons.

  19. Validation of a two-dimensional pollutant dispersion model in an isolated street canyon

    Energy Technology Data Exchange (ETDEWEB)

    Chan, T.L.; Dong, G.; Leung, C.W.; Cheung, C.S. [The Hong Kong Polytechnic University, Kowloon (Hong Kong). Research Centre for Combustion and Pollution Control, Department of Mechanical Engineering; Hung, W.T. [The Hong Kong Polytechnic University, Kowloon (Hong Kong). Department of Civil and Structural Engineering

    2002-07-01

    A two-dimensional numerical model based on Reynolds-averaged Navier-Stokes equations coupled with a series of standard, Renormalization Group (RNG) and realizable k-{epsilon} turbulence models was developed to simulate the fluid-flow development and pollutant dispersion within an isolated street canyon using the FLUENT code. In the present study, the validation of the numerical model was evaluated using an extensive experimental database obtained from the atmospheric boundary layer wind tunnel at the Meteorological Institute of Hamburg University, Germany (J. Wind Eng. Ind. Aerodyn. 62 (1996) 37). Among the studied turbulence models, the RNG k-{epsilon} turbulence model was found to be the most optimum turbulence model coupled with the two-dimensional street canyon model developed in the present study. Both the calculated and measured dimensionless pollutant concentrations have been shown to be less dependent on the variation of wind speed and source strength conditions for the studied street canyon aspect ratio of the B/H=1 case. However, the street canyon configuration has significant influence on the pollutant dispersion. The wider street and lower height of the buildings are favorable to pollutant dilution within the street canyon. The fluid-flow development has demonstrated that the rotative vortex or vortices generated within the urban street canyon can transport the pollutants from a line source to the wall surfaces of the buildings. (author)

  20. A Numerical Study on the Effects of Street‒canyon Aspect‒ratio on Reactive Pollutant Dispersion

    Science.gov (United States)

    Park, S. J.; Kim, J.

    2014-12-01

    In this study, the effects of street‒canyon aspect‒ratio on reactive pollutant dispersion were investigated using the coupled CFD‒chemistry model. For this, flow characteristics were analyzed first in street canyons with different aspect ratios and flow regimes were classified according to the building height. For each flow regime, dispersion characteristics were investigated in views of reactive pollutant concentration and VOCs‒NOX ratio. Finally, the relations between pollutant concentration and aspect ratio in urban street canyons were investigated. In the case of H/S = 1.0 (H is building height and S is street width), one clockwise‒rotating vortex appeared vertically and the reverse and outward flows were dominant near the street bottom. In the case of H/S = 2.0, two counter‒rotating vortices appeared vertically in the street canyon. The primary (secondary) vortex rotating clockwise (counterclockwise) was formed in upper (lower) layer. The flow patterns affected the reactive pollutant concentration in street canyons. As building height increased, mean concentration of NO decreased when one vortex was generated in street canyons and increased when two vortexes appeared in street canyons. O3 concentration showed almost contrasted tendency with those of NO because O3 was depleted by the NO titration.

  1. Vegetative communities, Davis and Lavender Canyons, Paradox Basin, Utah: ecosystem studies

    International Nuclear Information System (INIS)

    1983-04-01

    The major vegetative communities of Davis and Lavender canyons located in southeastern Utah are characterized. The report identifies potential secondary impacts and appropriate mitigation options. The Davis Canyon and Lavender Canyon Study Area contains nine major vegetative communities: galleta-shadscale, juniper-blackbrush, juniper-shadscale-ephedra, shadscale-ephedra, grayia-shadscale, juniper, drywash, greasewood, and riparian. The natural recovery times of these communities are exceedingly long. Natural reinvasion of various species would take from 15 to 100 years. No threatened or endangered plant species were identified in the study area. Davis and Lavender canyons have been subject to off-road vehicle activity and extensive grazing. The plant communities may be subject to additional impacts as a result of increased human activity and off-highway activities such as camping, hiking, and hunting could result in changes in cover, composition, and frequency of plant species. Mitigation options for potential impacts include shuttle-busing workers to the site from the highway and fencing site access roads to prevent vehicles from leaving the roads

  2. Fluctuating helical asymmetry and morphology of snails (Gastropoda in divergent microhabitats at 'Evolution Canyons I and II,' Israel.

    Directory of Open Access Journals (Sweden)

    Shmuel Raz

    Full Text Available Developmental instability of shelled gastropods is measured as deviations from a perfect equiangular (logarithmic spiral. We studied six species of gastropods at 'Evolution Canyons I and II' in Carmel and the Galilee Mountains, Israel, respectively. The xeric, south-facing, 'African' slopes and the mesic, north-facing, 'European' slopes have dramatically different microclimates and plant communities. Moreover, 'Evolution Canyon II' receives more rainfall than 'Evolution Canyon I.'We examined fluctuating asymmetry, rate of whorl expansion, shell height, and number of rotations of the body suture in six species of terrestrial snails from the two 'Evolution Canyons.' The xeric 'African' slope should be more stressful to land snails than the 'European' slope, and 'Evolution Canyon I' should be more stressful than 'Evolution Canyon II.' Only Eopolita protensa jebusitica showed marginally significant differences in fluctuating helical asymmetry between the two slopes. Contrary to expectations, asymmetry was marginally greater on the 'European' slope. Shells of Levantina spiriplana caesareana at 'Evolution Canyon I,' were smaller and more asymmetric than those at 'Evolution Canyon II.' Moreover, shell height and number of rotations of the suture were greater on the north-facing slopes of both canyons.Our data is consistent with a trade-off between drought resistance and thermoregulation in snails; Levantina was significantly smaller on the 'African' slope, for increasing surface area and thermoregulation, while Eopolita was larger on the 'African' slope, for reducing water evaporation. In addition, 'Evolution Canyon I' was more stressful than Evolution Canyon II' for Levantina.

  3. Safety analysis -- 200 Area Savannah River Plant, F-Canyon Operations. Supplement 4

    Energy Technology Data Exchange (ETDEWEB)

    Beary, M.M.; Collier, C.D.; Fairobent, L.A.; Graham, R.F.; Mason, C.L.; McDuffee, W.T.; Owen, T.L.; Walker, D.H.

    1986-02-01

    The F-Canyon facility is located in the 200 Separations Area and uses the Purex process to recover plutonium from reactor-irradiated uranium. The irradiated uranium is normally in the form of solid or hollow cylinders called slugs. These slugs are encased in aluminum cladding and are sent to the F-Canyon from the Savannah River Plant (SRP) reactor areas or from the Receiving Basin for Offsite Fuels (RBOF). This Safety Analysis Report (SAR) documents an analysis of the F-Canyon operations and is an update to a section of a previous SAR. The previous SAR documented an analysis of the entire 200 Separations Area operations. This SAR documents an analysis of the F-Canyon and is one of a series of documents for the Separations Area as specified in the Savannah River Implementation Plans. A substantial amount of the information supporting the conclusions of this SAR is found in the Systems Analysis. Some F-Canyon equipment has been updated during the time between the Systems Analysis and this SAR and a complete description of this equipment is included in this report. The primary purpose of the analysis was to demonstrate that the F-Canyon can be operated without undue risk to onsite or offsite populations and to the environment. In this report, risk is defined as the expected frequency of an accident, multiplied by the resulting radiological consequence in person-rem. The units of risk for radiological dose are person-rem/year. Maximum individual exposure values have also been calculated and reported.

  4. Submarine canyons off the Coromandel coast

    Digital Repository Service at National Institute of Oceanography (India)

    Varadachari, V.V.R.; Nair, R.R.; Murty, P.S.N.

    During the 26th Cruise of I.N.S. `KISTNA', a bathymetric survey was carried out in some detail off the Pondicherry coast. This survey has revealed the existence of three sets of distinctly separate canyons between Cuddalore and Palar River...

  5. parkITsmart: minimization of cruising for parking

    OpenAIRE

    Tsiaras, Christos; Hobi, Livio; Hofstetter, Fabian; Liniger, Samuel; Stiller, Burkhard

    2015-01-01

    Finding a parking space in urban areas is a daily challenge for drivers across the world, due to the increasing amount of vehicles and the limited amount of parking spaces. Drivers who are looking for a parking space in peak hours are often forced to drive around city blocks until they spot a free parking space. This process is termed in literature “cruising for parking” and is proven to (a) cost a lot of time and gas for drivers, (b) generate unnecessary traffic load, and (c) affect the envi...

  6. Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

    Science.gov (United States)

    Li, Xian-Xiang; Britter, Rex E.; Koh, Tieh Yong; Norford, Leslie K.; Liu, Chun-Ho; Entekhabi, Dara; Leung, Dennis Y. C.

    2010-11-01

    Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification was produced by heating the ground of the street canyon. Using the Boussinesq approximation, thermal buoyancy forces were taken into account in both the Navier-Stokes equations and the transport equation for subgrid-scale turbulent kinetic energy (TKE). The LESs were validated against experimental data obtained in wind-tunnel studies before the model was applied to study the detailed turbulence, temperature, and pollutant dispersion characteristics in the street canyon of aspect ratio 1. The effects of different Richardson numbers ( Ri) were investigated. The ground heating significantly enhanced mean flow, turbulence, and pollutant flux inside the street canyon, but weakened the shear at the roof level. The mean flow was observed to be no longer isolated from the free stream and fresh air could be entrained into the street canyon at the roof-level leeward corner. Weighed against higher temperature, the ground heating facilitated pollutant removal from the street canyon.

  7. Exploring en-route parking type and parking-search route choice

    DEFF Research Database (Denmark)

    Kaplan, Sigal; Bekhor, Sholomo

    2011-01-01

    This paper describes the first phase of an on-going research investigating the joint choice of parking type, parking facility and cruising-for-parking route. The importance of this issue derives from the significant share of cruising-for-parking traffic in urban areas, the relevance of parking po...

  8. 77 FR 8895 - Jimbilnan, Pinto Valley, Black Canyon, Eldorado, Ireteba Peaks, Nellis Wash, Spirit Mountain, and...

    Science.gov (United States)

    2012-02-15

    ..., Pinto Valley, Black Canyon, Eldorado, Ireteba Peaks, Nellis Wash, Spirit Mountain, and Bridge Canyon..., Eldorado, Ireteba Peaks, Nellis Wash, Spirit Mountain, and Bridge Canyon Wilderness Areas, Lake Mead... wilderness character; providing for reasonable use of Spirit Mountain and adjacent areas in a manner meeting...

  9. Parametric study of the dispersion aspects in a street-canyon area

    Energy Technology Data Exchange (ETDEWEB)

    Koutsourakis, N.; Neofytou, P.; Venetsanos, A.G.; Bartzis, J.G. [NCSR Demokritos (Greece). Environmental Research Lab.

    2004-07-01

    Continuously increasing vehicles' fleet is still considered to be the main emission factor in urban environments, despite the enormous progress of modern catalytic technology. Under that perspective, calculation of transportation induced pollutant dispersion is of augmented importance, especially within street canyons, where poor ventilation can result in awkward concentration levels. Computational Fluid Dynamics (CFD) studies have been conducted in the past by Neofytou, P. et al, so as to define appropriate locations for measuring-instrument placement by numerically simulating the flow and pollution dispersion fields in the vicinity of the measuring site taking into account the wind rose of the area and selecting locations of high pollution concentrations so that non-zero indications are assured. Vardoulakis, S. et al, provides a general overview of the street-canyon studies concerning both modelling and experimental investigations and offers plenty of references on air quality within street canyons. Besides air-quality, street canyon CFD studies have also been performed to evaluate accident consequences and hydrogen safety, Venetsanos A. et al. The current study examines a real street canyon in Thessaloniki, Greece. It was performed in order to examine dispersion patterns for different parameters' scenarios and help deciding where to place actual pollutant measurement instruments to better capture traffic pollution data. Various wind directions and speeds are examined and height influence on concentration levels is investigated. Complex area geometry is a key factor of the whole study. (orig.)

  10. Carbonaceous aerosol particles from common vegetation in the Grand Canyon

    International Nuclear Information System (INIS)

    Hallock, K.A.; Mazurek, M.A.; Cass, G.R.

    1992-05-01

    The problem of visibility reduction in the Grand Canyon due to fine organic aerosol particles in the atmosphere has become an area of increased environmental concern. Aerosol particles can be derived from many emission sources. In this report, we focus on identifying organic aerosols derived from common vegetation in the Grand Canyon. These aerosols are expected to be significant contributors to the total atmospheric organic aerosol content. Aerosol samples from living vegetation were collected by resuspension of surface wax and resin components liberated from the leaves of vegetation common to areas of the Grand Canyon. The samples were analyzed using high-resolution gas chromatography/mass spectrometry (GC/MS). Probable identification of compounds was made by comparison of sample spectra with National Institute of Standards and Technology (NIST) mass spectral references and positive identification of compounds was made when possible by comparison with authentic standards as well as NIST references. Using these references, we have been able to positively identify the presence of n-alkane and n-alkanoic acid homolog series in the surface waxes of the vegetation sampled. Several monoterpenes, sesquiterpenes, and diterpenes were identified also as possible biogenic aerosols which may contribute to the total organic aerosol abundance leading to visibility reduction in the Grand Canyon

  11. The urban canyon and building energy use: Urban density versus daylight and passive solar gains

    DEFF Research Database (Denmark)

    Strømann-Andersen, Jakob Bjørn; Sattrup, Peter Andreas

    2011-01-01

    .It was found that the geometry of urban canyons has an impact on total energy consumption in the range of up to +30% for offices and +19% for housing, which shows that the geometry of urban canyons is a key factor in energy use in buildings. It was demonstrated how the reflectivity of urban canyons plays...

  12. iParking: an intelligent indoor location-based smartphone parking service.

    Science.gov (United States)

    Liu, Jingbin; Chen, Ruizhi; Chen, Yuwei; Pei, Ling; Chen, Liang

    2012-10-31

    Indoor positioning technologies have been widely studied with a number of solutions being proposed, yet substantial applications and services are still fairly primitive. Taking advantage of the emerging concept of the connected car, the popularity of smartphones and mobile Internet, and precise indoor locations, this study presents the development of a novel intelligent parking service called iParking. With the iParking service, multiple parties such as users, parking facilities and service providers are connected through Internet in a distributed architecture. The client software is a light-weight application running on a smartphone, and it works essentially based on a precise indoor positioning solution, which fuses Wireless Local Area Network (WLAN) signals and the measurements of the built-in sensors of the smartphones. The positioning accuracy, availability and reliability of the proposed positioning solution are adequate for facilitating the novel parking service. An iParking prototype has been developed and demonstrated in a real parking environment at a shopping mall. The demonstration showed how the iParking service could improve the parking experience and increase the efficiency of parking facilities. The iParking is a novel service in terms of cost- and energy-efficient solution.

  13. iParking: An Intelligent Indoor Location-Based Smartphone Parking Service

    Directory of Open Access Journals (Sweden)

    Liang Chen

    2012-10-01

    Full Text Available Indoor positioning technologies have been widely studied with a number of solutions being proposed, yet substantial applications and services are still fairly primitive. Taking advantage of the emerging concept of the connected car, the popularity of smartphones and mobile Internet, and precise indoor locations, this study presents the development of a novel intelligent parking service called iParking. With the iParking service, multiple parties such as users, parking facilities and service providers are connected through Internet in a distributed architecture. The client software is a light-weight application running on a smartphone, and it works essentially based on a precise indoor positioning solution, which fuses Wireless Local Area Network (WLAN signals and the measurements of the built-in sensors of the smartphones. The positioning accuracy, availability and reliability of the proposed positioning solution are adequate for facilitating the novel parking service. An iParking prototype has been developed and demonstrated in a real parking environment at a shopping mall. The demonstration showed how the iParking service could improve the parking experience and increase the efficiency of parking facilities. The iParking is a novel service in terms of cost- and energy-efficient solution.

  14. iParking: An Intelligent Indoor Location-Based Smartphone Parking Service

    Science.gov (United States)

    Liu, Jingbin; Chen, Ruizhi; Chen, Yuwei; Pei, Ling; Chen, Liang

    2012-01-01

    Indoor positioning technologies have been widely studied with a number of solutions being proposed, yet substantial applications and services are still fairly primitive. Taking advantage of the emerging concept of the connected car, the popularity of smartphones and mobile Internet, and precise indoor locations, this study presents the development of a novel intelligent parking service called iParking. With the iParking service, multiple parties such as users, parking facilities and service providers are connected through Internet in a distributed architecture. The client software is a light-weight application running on a smartphone, and it works essentially based on a precise indoor positioning solution, which fuses Wireless Local Area Network (WLAN) signals and the measurements of the built-in sensors of the smartphones. The positioning accuracy, availability and reliability of the proposed positioning solution are adequate for facilitating the novel parking service. An iParking prototype has been developed and demonstrated in a real parking environment at a shopping mall. The demonstration showed how the iParking service could improve the parking experience and increase the efficiency of parking facilities. The iParking is a novel service in terms of cost- and energy-efficient solution. PMID:23202179

  15. National Parks

    Data.gov (United States)

    Department of Transportation — National Park Service unit boundaries (NTAD). These park boundaries signify legislative boundary definitions and local park names have been consolidated according to...

  16. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-01-01

    positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking

  17. 76 FR 36450 - Approval and Promulgation of Air Quality Implementation Plans; State of Nevada; Regional Haze...

    Science.gov (United States)

    2011-06-22

    ... regional haze. This legislation established the Grand Canyon Visibility Transport Commission (GCVTC), which... Canyon National Park (NP), Sycamore Canyon Wilderness Area (WA), Pine Mountain WA, Mazatal WA, and Sierra Ancha WA. In California, they are Desolation WA, Dome Land WA, Hoover WA, Joshua Tree NP, Kaiser WA...

  18. Captured in Stone: Women in the Rock Art of Canyon de Chelly.

    Science.gov (United States)

    Travis, Tara

    1997-01-01

    Describes the pictographs (painted images on stone) and petroglyphs (pecked images on stone) found in the Canyon de Chelly National Monument in Arizona. Canyon de Chelly includes one of the largest concentrations of American Indian rock art in the southwest. Discusses the depiction of women in these images. (MJP)

  19. Trees as environmental modifier to improve street canyon for pedestrian activities in Muscat

    Science.gov (United States)

    Khudhayer, Wael A.; Shaaban, Awni K.; Sukor, Nur Sabahiah Abdul

    2017-10-01

    Street shading efficiency is a function of orientation and profile proportion of its height to width. Under high sun altitude conditions, minimization of solar irradiance within the urban environment may often be a significant criterion in urban design. This reduction in solar irradiance achieved when the obstruction angle is large (high H/W ratio, H=height, W=width). High H/W values often lessen the solar access to streets. The horizontal sprawl of Muscat region is an example of low H/W ratio represented the remarkable challenge that causes the lack of shading rates in the urban street. This characteristic proliferates the negative impact on the pedestrian activities in the urban street. This research aims to improve the morphology of the street to promote the pedestrian behavior. The amendment based on suggesting different configurations of trees to increase effective shading of the urban street in Muscat. The street canyon abstracted into a virtual elongated channel formed of floor and walls of equal heights on both sides. Four street orientations (E/W, N/S, NE/SW, NW/SE) and three H/W ratio (0.5,1 and 2) are considered sufficient representative of street typologies. A mathematical model developed for calculation of shading efficiency of each street canyon. The trees assumed in this study as canyon's modifier to adjust the low H/W ratio of a street canyon to a higher one. Local trees and other plants in Muscat were studied concerning their morphology. The analysis selected two case study in Muscat to investigate the shading performance of their street canyons subsequently propose the modifications to improve it. The research concluded that the suggested changes of the street canyon by using a particular type of trees could increase the H/W ratio of street canyon significantly.

  20. Wind tunnel simulation of air pollution dispersion in a street canyon.

    Science.gov (United States)

    Civis, Svatopluk; Strizík, Michal; Janour, Zbynek; Holpuch, Jan; Zelinger, Zdenek

    2002-01-01

    Physical simulation was used to study pollution dispersion in a street canyon. The street canyon model was designed to study the effect of measuring flow and concentration fields. A method of C02-laser photoacoustic spectrometry was applied for detection of trace concentration of gas pollution. The advantage of this method is its high sensitivity and broad dynamic range, permitting monitoring of concentrations from trace to saturation values. Application of this method enabled us to propose a simple model based on line permeation pollutant source, developed on the principle of concentration standards, to ensure high precision and homogeneity of the concentration flow. Spatial measurement of the concentration distribution inside the street canyon was performed on the model with reference velocity of 1.5 m/s.

  1. 77 FR 59607 - Black Canyon Hydro, LLC; Notice of Environmental Site Review

    Science.gov (United States)

    2012-09-28

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14110-001] Black Canyon Hydro, LLC; Notice of Environmental Site Review On Wednesday, October 3, 2012, at 3 p.m., Commission staff will be participating in an environmental site review for the proposed Black Canyon Hydroelectric Project. All interested participants should mee...

  2. Hydroacoustic signatures of Colorado Riverbed sediments in Marble and Grand Canyons using multibeam sonar

    Science.gov (United States)

    Buscombe, Daniel D.; Grams, Paul E.; Kaplinski, Matthew; Tusso, Robert B.; Rubin, David M.

    2015-01-01

    Grand Canyon National Park have been studied for several decades (e.g. Howard and Dolan, 1981; Rubin et al., 2002). Particular focus has been given to sandbars in large eddies downstream of tributary debris fans (Schmidt, 1990) because they are considered valuable resources by stakeholders and managers. Due to the severe limitations in sand supply imposed by Glen Canyon Dam (Howard and Dolan, 1981; Topping et al., 2000; Hazel et al., 2006), understanding the effectiveness of sandbar management practices, such as controlled floods (Rubin et al. 2002; Topping et al., 2006; Hazel et al., 2010), and the long-term fate of sand in Grand Canyon over decadal timescales, requires construction of accurate sand budgets, which involves detailed monitoring of influx, efflux and changes in sand storage (Topping et al., 2000; Topping et al., 2010; Grams et al., 2013) and assessments of uncertainties in sand-budget calculations (Grams et al., 2013). In order to estimate the sand budget, it is necessary to estimate what component of observed morphological changes is sand and what component is coarser. Grams et al. (2013) classified sand and coarse substrates using topographic roughness derived from digital elevation models, but the classification skill was estimated to be only 60-70%. In addition, sand bedforms had to be delineated manually, and validation was based on grain-size observations with positional uncertainties up to tens of meters. Because the morphology of the Colorado riverbed in Grand Canyon is mapped - to a large extent - using MBES (Kaplinski et al., 2009), the primary motivation for the present study is to examine how uncertainties in sand budgets can be constrained by producing maps of surface sediment types using the completely automated methods of Buscombe et al (2014b, 2014c) based on statistical analysis of MBES acoustic backscatter.

  3. Trees in urban street canyons and their impact on the dispersion of automobile exhausts

    OpenAIRE

    Gromke, Christof; Ruck, Bodo

    2007-01-01

    The aim of the present study is to clarify the influence of trees on the dispersion of automobile exhausts in urban street canyons. For this purpose, measurements have been performed with a small scale wind tunnel model of an idealized, isolated street canyon with model trees placed along the canyon center axis. Sulfur hexafluoride (SF6) was released from a line source embedded in the street surface, simulating vehicle exhaust emissions. The influence of various tree planting arrangements on ...

  4. Evaluation of Integrating the Invasive Species Forecasting System to Support National Park Service Decisions on Fire Management Activities and Invasive Plant Species Control

    Science.gov (United States)

    Ma, Peter; Morisette, T.; Rodman, Ann; McClure, Craig; Pedelty, Jeff; Benson, Nate; Paintner, Kara; Most, Neal; Ullah, Asad; Cai, Weijie; hide

    2007-01-01

    The USGS and NASA, in conjunction with Colorado State University, George Mason University and other partners, have developed the Invasive Species Forecasting System (ISFS), a flexible tool that capitalizes on NASA's remote sensing resource to produce dynamic habitat maps of invasive terrestrial plant species across the United States. In 2006 ISFS was adopted to generate predictive invasive habitat maps to benefit noxious plant and fire management teams in three major National Park systems: The Greater Yellowstone Area (Yellowstone / Grand Tetons National Parks), Sequoia and Kings Canyon National Park, and interior Alaskan (between Denali, Gates of The Arctic and Yukon-Charley). One of the objectives of this study is to explore how the ISFS enhances decision support apparatus in use by National Park management teams. The first step with each park system was to work closely with park managers to select top-priority invasive species. Specific species were chosen for each study area based on management priorities, availability of observational data, and their potential for invasion after fire disturbances. Once focal species were selected, sources of presence/absence data were collected from previous surveys for each species in and around the Parks. Using logistic regression to couple presence/absence points with environmental data layers, the first round of ISFS habitat suitability maps were generated for each National Park system and presented during park visits over the summer of 2006. This first engagement provided a demonstration of what the park service can expect from ISFS and initiated the ongoing dialog on how the parks can best utilized the system to enhance their decisions related to invasive species control. During the park visits it was discovered that separate "expert opinion" maps would provide a valuable baseline to compare against the ISFS model output. Opinion maps are a means of spatially representing qualitative knowledge into a quantitative two

  5. Rural Latino youth park use: characteristics, park amenities, and physical activity.

    Science.gov (United States)

    Perry, Cynthia K; Saelens, Brain E; Thompson, Beti

    2011-06-01

    Less than half of youth engage in sufficient physical activity to achieve health benefits. Key environmental factors of park and recreation spaces may influence youth physical activity. We sought to ascertain youth characteristics and behaviors that attract youth to parks with specific amenities and encourage physical activity while at the parks in a rural, predominantly Latino community. We examined the quality of amenities in the 13 parks and recreation spaces that middle school aged youth have access to in their community using the Environmental Assessment of Parks and Recreation Spaces (EAPRS) tool. Middle school students completed surveys in the school classroom (n = 1,102) regarding park use, physical activity, and intrapersonal characteristics (e.g., motivators). We used logistic regression to identify correlates of any park use, use of higher quality field and court parks, and active and sedentary park use. Younger age, participation in an after school activity, and identification of a team as a motivator were positively associated with any park use. Use of higher quality court and field parks was associated with participation in an after school activity and being Latino. The odds of being active in the parks were greater for boys and Latinos. Older age and alcohol use are correlated with being sedentary at the park, while odds of being sedentary at the park were lower for boys and youth who met physical activity guidelines. Organized team activities may encourage active use of higher quality fields and courts parks by Latino youth; thereby, increasing their level of physical activity.

  6. Migration of Sr-20, Cs-137, and Pu-239/240 in Canyon below Los Alamos outfall

    International Nuclear Information System (INIS)

    Murphy, J.M.; Mason, C.F.V.; Boak, J.M.; Longmire, P.A.

    1996-01-01

    Technical Area-21 (TA-21) of Los Alamos National Laboratory (LANL) is on a mesa bordered by two canyons DP Canyon and Los Alamos (LA) Canyon. DP Canyon is a small semiarid watershed with a well defined channel system where the stream flow is ephemeral. TA-21 has had a complex history of waste disposal as research to determine the chemical and metallurgical properties of nuclear materials occurred here from 1945-1978. Due to these operations, the TA-21 mesa top and bordering canyons have been monitored and characterized by the LANL Environmental Restoration Program. Results identify radionuclide values at outfall. 21-011 (k) which exceed Screening Action Levels, and points along DP Canyon which exceed regional background levels. The radiocontaminants considered in this study are strontium-90, cesium-137, and plutonium-239. This research examines sediment transport and speciation of radionuclide contaminant migration from a source term named SWMU 21-011 (k) down DP Canyon. Three dimensional surface plots of data from 1977-1994 are used to portray the transport and redistribution of radioactive contaminants in an alluvial stream channel. An overall decrease in contamination concentration since 1983 has been observed which could be due to more stringent laboratory controls and also to the removal of main plutonium processing laboratories to another site

  7. Migration of Sr-20, Cs-137, and Pu-239/240 in Canyon below Los Alamos outfall

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.M.; Mason, C.F.V.; Boak, J.M.; Longmire, P.A.

    1996-04-01

    Technical Area-21 (TA-21) of Los Alamos National Laboratory (LANL) is on a mesa bordered by two canyons DP Canyon and Los Alamos (LA) Canyon. DP Canyon is a small semiarid watershed with a well defined channel system where the stream flow is ephemeral. TA-21 has had a complex history of waste disposal as research to determine the chemical and metallurgical properties of nuclear materials occurred here from 1945-1978. Due to these operations, the TA-21 mesa top and bordering canyons have been monitored and characterized by the LANL Environmental Restoration Program. Results identify radionuclide values at outfall. 21-011 (k) which exceed Screening Action Levels, and points along DP Canyon which exceed regional background levels. The radiocontaminants considered in this study are strontium-90, cesium-137, and plutonium-239. This research examines sediment transport and speciation of radionuclide contaminant migration from a source term named SWMU 21-011 (k) down DP Canyon. Three dimensional surface plots of data from 1977-1994 are used to portray the transport and redistribution of radioactive contaminants in an alluvial stream channel. An overall decrease in contamination concentration since 1983 has been observed which could be due to more stringent laboratory controls and also to the removal of main plutonium processing laboratories to another site.

  8. Human rhinovirus capsid dynamics is controlled by canyon flexibility

    International Nuclear Information System (INIS)

    Reisdorph, Nichole; Thomas, John J.; Katpally, Umesh; Chase, Elaine; Harris, Ken; Siuzdak, Gary; Smith, Thomas J.

    2003-01-01

    Quantitative enzyme accessibility experiments using nano liquid chromatography electrospray mass spectrometry combined with limited proteolysis and isotope-labeling was used to examine the dynamic nature of the human rhinovirus (HRV) capsid in the presence of three antiviral compounds, a neutralizing Fab, and drug binding cavity mutations. Using these methods, it was found that the antivirals WIN 52084 and picovir (pleconaril) stabilized the capsid, while dansylaziridine caused destabilization. Site-directed mutations in the drug-binding cavity were found to stabilize the HRV14 capsid against proteolytic digestion in a manner similar to WIN 52084 and pleconaril. Antibodies that bind to the NIm-IA antigenic site and penetrate the canyon were also observed to protect the virion against proteolytic cleavage. These results demonstrate that quantifying the effects of antiviral ligands on protein 'breathing' can be used to compare their mode of action and efficacy. In this case, it is apparent that hydrophobic antiviral agents, antibodies, or mutations in the canyon region block viral breathing. Therefore, these studies demonstrate that mobility in the canyon region is a major determinant in capsid breathing

  9. Turbulent ventilation of a street canyon

    DEFF Research Database (Denmark)

    Nielsen, Morten

    2000-01-01

    A selection of turbulence data corresponding to 185 days of field measurements has een analysed. The non-ideal building geometry influenced the circulation patterns in the street canyon and the largest average vertical velocities were observed in the wake of an unbroken line of buildings. The sta...

  10. Compilation of PRF Canyon Floor Pan Sample Analysis Results

    Energy Technology Data Exchange (ETDEWEB)

    Pool, Karl N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wahl, Jon H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greenwood, Lawrence R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Deborah S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McNamara, Bruce K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Scheele, Randall D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Delegard, Calvin H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Garrett N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-06-30

    On September 28, 2015, debris collected from the PRF (236-Z) canyon floor, Pan J, was observed to exhibit chemical reaction. The material had been transferred from the floor pan to a collection tray inside the canyon the previous Friday. Work in the canyon was stopped to allow Industrial Hygiene to perform monitoring of the material reaction. Canyon floor debris that had been sealed out was sequestered at the facility, a recovery plan was developed, and drum inspections were initiated to verify no additional reactions had occurred. On October 13, in-process drums containing other Pan J material were inspected and showed some indication of chemical reaction, limited to discoloration and degradation of inner plastic bags. All Pan J material was sealed back into the canyon and returned to collection trays. Based on the high airborne levels in the canyon during physical debris removal, ETGS (Encapsulation Technology Glycerin Solution) was used as a fogging/lock-down agent. On October 15, subject matter experts confirmed a reaction had occurred between nitrates (both Plutonium Nitrate and Aluminum Nitrate Nonahydrate (ANN) are present) in the Pan J material and the ETGS fixative used to lower airborne radioactivity levels during debris removal. Management stopped the use of fogging/lock-down agents containing glycerin on bulk materials, declared a Management Concern, and initiated the Potential Inadequacy in the Safety Analysis determination process. Additional drum inspections and laboratory analysis of both reacted and unreacted material are planned. This report compiles the results of many different sample analyses conducted by the Pacific Northwest National Laboratory on samples collected from the Plutonium Reclamation Facility (PRF) floor pans by the CH2MHill’s Plateau Remediation Company (CHPRC). Revision 1 added Appendix G that reports the results of the Gas Generation Rate and methodology. The scope of analyses requested by CHPRC includes the determination of

  11. Assesment of longwave radiation effects on air quality modelling in street canyons

    Science.gov (United States)

    Soucasse, L.; Buchan, A.; Pain, C.

    2016-12-01

    Computational Fluid Dynamics is widely used as a predictive tool to evaluate people's exposure to pollutants in urban street canyons. However, in low-wind conditions, flow and pollutant dispersion in the canyons are driven by thermal effects and may be affected by longwave (infrared) radiation due to the absorption and emission of water vapor contained in the air. These effects are mostly ignored in the literature dedicated to air quality modelling at this scale. This study aims at quantifying the uncertainties due to neglecting thermal radiation in air quality models. The Large-Eddy-Simulation of air flow in a single 2D canyon with a heat source on the ground is considered for Rayleigh and Reynolds numbers in the range of [10e8-10e10] and [5.10e3-5.10e4] respectively. The dispersion of a tracer is monitored once the statistically steady regime is reached. Incoming radiation is computed for a mid-latitude summer atmosphere and canyon surfaces are assumed to be black. Water vapour is the only radiating molecule considered and a global model is used to treat the spectral dependancy of its absorption coefficient. Flow and radiation fields are solved in a coupled way using the finite element solvers Fluidity and Fetch which have the capability of adapting their space and angular resolution according to an estimate of the solution error. Results show significant effects of thermal radiation on flow patterns and tracer dispersion. When radiation is taken into account, the air is heated far from the heat source leading to a stronger natural convection flow. The tracer is then dispersed faster out of the canyon potentially decreasing people's exposure to pollution within the street canyon.

  12. Turkish Straits System and Southern Black Sea: Exchange. Mixing and Shelf / Canyon Interactions

    Science.gov (United States)

    Özsoy, Emin; Gürses, Özgür; Tutsak, Ersin

    2015-04-01

    Based largely on an experiment employing high-resolution measurements carried out in June-July 2013 and re-interpretation of past experiments, the oceanographic variability of the exchange through the Turkish Straits System (TSS) and the interactions with the southern Black Sea are revealed through CTD, ADCP, oxygen and light transmission measurements. The exchange flow is primarily governed by the complex topography spanning two narrow straits, wide continental shelf regions, steep slopes and numerous canyons connecting deep basins. Water properties and currents in the high energy environment depends on the mosaic of fine-scale processes and pathways. The TSS, often approximated as a two-layer system has a hydraulically controlled, upper ocean and straits intensified regime, leading to surface jets and bottom plumes participating in mixing and renewal processes. The exit of the 'Mediterranean effluent' onto the Black Sea past a sill overflow from the Bosphorus passes through two subsequent hydraulic jumps and proceeds along a narrow canyon that veers to the west clear of the greater Bosphorus Canyon finally cascading down the few small canyons. A diffusive spread from the bottom vein of salty water reforms to the east and spills down the Bosphorus Canyon. The suspended particulate signature of the cascade, as well as its influence in hydrography is traced over the shelf and slope waters and through the numerous canyons into deep water where the reformed flow is found to sustain signatures of the past evolution of intrusive waters. An evaluation of the processes is given with reference to model development carried out in parallel to the analyses of the measurements.

  13. Analysis of Parking Reliability Guidance of Urban Parking Variable Message Sign System

    Directory of Open Access Journals (Sweden)

    Zhenyu Mei

    2012-01-01

    Full Text Available Operators of parking guidance and information systems (PGIS often encounter difficulty in determining when and how to provide reliable car park availability information to drivers. Reliability has become a key factor to ensure the benefits of urban PGIS. The present paper is the first to define the guiding parking reliability of urban parking variable message signs (VMSs. By analyzing the parking choice under guiding and optional parking lots, a guiding parking reliability model was constructed. A mathematical program was formulated to determine the guiding parking reliability of VMS. The procedures were applied to a numerical example, and the factors that affect guiding reliability were analyzed. The quantitative changes of the parking berths and the display conditions of VMS were found to be the most important factors influencing guiding reliability. The parking guiding VMS achieved the best benefit when the parking supply was close to or was less than the demand. The combination of a guiding parking reliability model and parking choice behavior offers potential for PGIS operators to reduce traffic congestion in central city areas.

  14. Atlanto-occipital fusion and spondylolisthesis in an Anasazi skeleton from Bright Angel Ruin, Grand Canyon National Park, Arizona.

    Science.gov (United States)

    Merbs, C F; Euler, R C

    1985-08-01

    The skeleton of a middle-aged female showing an unusual pattern of congenital, traumatic, and degenerative pathology was recovered from a small Kayenta Anasazi site located near the confluence of Bright Angel Creek with the Colorado River in the Inner Gorge of Grand Canyon. The atlas is fused with the base of the skull and C2 is fused with C3. The cervical region was subjected to hyperextension, perhaps through use of a tumpline, with resultant reduction of the neural canal to 8 mm, a condition that quite likely led to neurological problems. The skeleton also includes a depression fracture of the lateral condyle of the left tibia. Complete, bilateral spondylolysis of L5 led to an olisthesis of approximately 15 mm. The disc between L5 and S1 then ossified, most likely from staphylococcus bacteremia, making the olisthesis permanent and thereby creating a unique arachaeological specimen. Although spondylolysis is usually viewed as a stress fracture, the general pattern of pathology in this individual makes it necessary to consider an etiology of acute trauma.

  15. Long-term surveillance plan for the Burro Canyon disposal cell, Slick Rock, Colorado

    International Nuclear Information System (INIS)

    1996-11-01

    This long-term surveillance plant (LTSP) describes the US Department of energy's (DOE) long-term care program for the Uranium Mill Tailings Remediation Action (UMTRA) Project's burro Canyon disposal cell in San Miguel County, Colorado. This LTSP describes the long-term surveillance program the DOE will implement to ensure that the Burro Canyon disposal cell performs as designed. The program is based on site inspections to identify threats to disposal cell integrity. No ground water monitoring will be required at the Burro Canyon disposal cell because the ground water protection strategy is supplemental standards based on low-yield from the upper-most aquifer

  16. Effectiveness of green infrastructure for improvement of air quality in urban street canyons.

    Science.gov (United States)

    Pugh, Thomas A M; Mackenzie, A Robert; Whyatt, J Duncan; Hewitt, C Nicholas

    2012-07-17

    Street-level concentrations of nitrogen dioxide (NO(2)) and particulate matter (PM) exceed public health standards in many cities, causing increased mortality and morbidity. Concentrations can be reduced by controlling emissions, increasing dispersion, or increasing deposition rates, but little attention has been paid to the latter as a pollution control method. Both NO(2) and PM are deposited onto surfaces at rates that vary according to the nature of the surface; deposition rates to vegetation are much higher than those to hard, built surfaces. Previously, city-scale studies have suggested that deposition to vegetation can make a very modest improvement (street canyons. This study shows that increasing deposition by the planting of vegetation in street canyons can reduce street-level concentrations in those canyons by as much as 40% for NO(2) and 60% for PM. Substantial street-level air quality improvements can be gained through action at the scale of a single street canyon or across city-sized areas of canyons. Moreover, vegetation will continue to offer benefits in the reduction of pollution even if the traffic source is removed from city centers. Thus, judicious use of vegetation can create an efficient urban pollutant filter, yielding rapid and sustained improvements in street-level air quality in dense urban areas.

  17. The Influence of Roof Material on Diurnal Urban Canyon Breathing

    Science.gov (United States)

    Abuhegazy, Mohamed; Yaghoobian, Neda

    2017-11-01

    Improvements in building energy use, air quality in urban canyons and in general urban microclimates require understanding the complex interaction between urban morphology, materials, climate, and inflow conditions. Review of the literature indicates that despite a long history of valuable urban microclimate studies, more comprehensive approaches are needed to address energy, and heat and flow transport in urban areas. In this study, a more comprehensive simulation of the diurnally varying street canyon flow and associated heat transport is numerically investigated, using Large-eddy Simulation (LES). We use computational modeling to examine the impact of diurnal variation of the heat fluxes from urban surfaces on the air flow and temperature distribution in street canyons with a focus on the role of roof materials and their temperature footprints. A detailed building energy model with a three-dimensional raster-type geometry provides urban surface heat fluxes as thermal boundary conditions for the LES to determine the key aero-thermodynamic factors that affect urban street ventilation.

  18. Prehistoric deforestation at Chaco Canyon?

    Science.gov (United States)

    Wills, W H; Drake, Brandon L; Dorshow, Wetherbee B

    2014-08-12

    Ancient societies are often used to illustrate the potential problems stemming from unsustainable land-use practices because the past seems rife with examples of sociopolitical "collapse" associated with the exhaustion of finite resources. Just as frequently, and typically in response to such presentations, archaeologists and other specialists caution against seeking simple cause-and effect-relationships in the complex data that comprise the archaeological record. In this study we examine the famous case of Chaco Canyon, New Mexico, during the Bonito Phase (ca. AD 860-1140), which has become a prominent popular illustration of ecological and social catastrophe attributed to deforestation. We conclude that there is no substantive evidence for deforestation at Chaco and no obvious indications that the depopulation of the canyon in the 13th century was caused by any specific cultural practices or natural events. Clearly there was a reason why these farming people eventually moved elsewhere, but the archaeological record has not yet produced compelling empirical evidence for what that reason might have been. Until such evidence appears, the legacy of Ancestral Pueblo society in Chaco should not be used as a cautionary story about socioeconomic failures in the modern world.

  19. Analysis of Parking Reliability Guidance of Urban Parking Variable Message Sign System

    OpenAIRE

    Zhenyu Mei; Ye Tian; Dongping Li

    2012-01-01

    Operators of parking guidance and information systems (PGIS) often encounter difficulty in determining when and how to provide reliable car park availability information to drivers. Reliability has become a key factor to ensure the benefits of urban PGIS. The present paper is the first to define the guiding parking reliability of urban parking variable message signs (VMSs). By analyzing the parking choice under guiding and optional parking lots, a guiding parking reliability model was constru...

  20. Experimental simulation of air quality in street canyon under changes of building orientation and aspect ratio.

    Science.gov (United States)

    Yassin, Mohamed F; Ohba, Masaake

    2012-09-01

    To assist validation of numerical simulations of urban pollution, air quality in a street canyon was investigated using a wind tunnel as a research tool under neutral atmospheric conditions. We used tracer gas techniques from a line source without buoyancy. Ethylene (C(2)H(4)) was used as the tracer gas. The street canyon model was formed of six parallel building rows of the same length. The flow and dispersion field was analyzed and measured using a hot-wire anemometer with split fiber probe and fast flame ionization detector. The diffusion flow field in the boundary layer within the street canyon was examined at different locations, with varying building orientations (θ=90°, 112.5°, 135° and 157.5°) and street canyon aspect ratios (W/H=1/2, 3/4 and 1) downwind of the leeward side of the street canyon model. Results show that velocity increases with aspect ratio, and with θ>90°. Pollutant concentration increases as aspect ratio decreases. This concentration decreases exponentially in the vertical direction, and decreases as θ increases from 90°. Measured pollutant concentration distributions indicate that variability of building orientation and aspect ratio in the street canyon are important for estimating air quality in the canyon. The data presented here can be used as a comprehensive database for validation of numerical models.

  1. Flow and Pollutant Transport in Urban Street Canyons of Different Aspect Ratios with Ground Heating: Large-Eddy Simulation

    Science.gov (United States)

    Li, Xian-Xiang; Britter, Rex E.; Norford, Leslie K.; Koh, Tieh-Yong; Entekhabi, Dara

    2012-02-01

    A validated large-eddy simulation model was employed to study the effect of the aspect ratio and ground heating on the flow and pollutant dispersion in urban street canyons. Three ground-heating intensities (neutral, weak and strong) were imposed in street canyons of aspect ratio 1, 2, and 0.5. The detailed patterns of flow, turbulence, temperature and pollutant transport were analyzed and compared. Significant changes of flow and scalar patterns were caused by ground heating in the street canyon of aspect ratio 2 and 0.5, while only the street canyon of aspect ratio 0.5 showed a change in flow regime (from wake interference flow to skimming flow). The street canyon of aspect ratio 1 does not show any significant change in the flow field. Ground heating generated strong mixing of heat and pollutant; the normalized temperature inside street canyons was approximately spatially uniform and somewhat insensitive to the aspect ratio and heating intensity. This study helps elucidate the combined effects of urban geometry and thermal stratification on the urban canyon flow and pollutant dispersion.

  2. Yuntaishan Global Geopark VS Grand Canyon World Heritage Site A Contrast of Yuntai/Grand Canyon Physiognomy

    Science.gov (United States)

    Ting, Zhao; Xun, Zhao

    2017-04-01

    Yuntai/Grand Canyon is a result of long-term historical evolution and a rare natural heritage of the world. With its rich heritages of geological physiognomy, systematic geological record, abundant biological fossil combination, long history of structural evolution, they are of contrastive research values worldwide. The Grand Canyon was declared national natural heritage on eleventh January, and in 1979 it was entitled World Natural Heritage Site. Though the two major sites are separated by tremendous seas, they reached agreements in the protection of natural heritages worldwide on account of the shared ideas of society, demonstrating to our children how can we protect the two scenery sites. Keyword:Geopark, Geoheritage, Yuntai Landform, GrandCanyon Mt. Taihang rises from the central part of north China and extends to the west edge of North China Plain. Towering, and with ragged peaks, precarious cliffs, long strips of walls, deep valleys and shaded streams, Mt. Taihang poses impressive sights with its clear water, dense forest and wonderful sceneries. It is indeed the east slope of Qin-Jin Plateau. Indeed things tend to coincide. On the other side of the Pacific Ocean, along the west edge of north America and on the wide and spacious Colorado Plateau, there is a winding and deep valley where there are layers of rocks, extensive sharp cliffs, intercrossing ravines and forests of peaks; it is totally impressive. Both sceneries are known to the world for their beauty. Identical geological conditions and similar history of evolution left two natural sights that resemble each other so much. Geological changes are infinite, and sedimentation works in similar ways on both sights; and the changing ecological environment gives the world two colorful and comparable geological records. Both sights are merely brief periods in the long history of earth development, but they show us how cradles of human proliferation and social civilization had looked. 1,Comparison of two parks

  3. Environmental assessment of remedial action, acid/middle Pueblo Canyon, Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    1982-08-01

    The radiological survey of the former radioactive waste treatment plant site (TA-45), Acid Canyon, and Pueblo Canyon found residual radioactivity at the site itself and in the channel and banks of Acid, Pueblo, and lower Los Alamos Canyons, all the way to the Rio Grande. The largest reservoir of radioactive material is in lower Pueblo Canyon, which is on DOE property. The only areas where residual radioactivity exceeds the proposed cleanup criteria are at the former vehicle decontamination facility, located between the former treatment plant site and Acid Canyon, around the former untreated waste outfall and for a short distance below, and in two small areas farther down in Acid Canyon. The three alternatives proposed are (1) to take no action, (2) to fence the areas where the residual radioactivity exceeds the proposed criteria (minimal action), and (3) to clean up the former vehicle decontamination facility and around the former untreated waste outfall. Calculations based on actual measurements indicate that the annual dose at the location having the greatest residual radioactivity would be about 12% of the applicable guideline. Most doses are much smaller than that. No environmental impacts are associated with either the no-action or minimal action alternatives. The impact associated with the cleanup alternative is very small. The preferred alternative is to clean up the areas around the former vehicle decontamination facility and the untreated waste outfall. This course of action is recommended not because of any real danger associated with the residual radioactivity, but rather because the cleanup operation is a minor effort and would conform with the ALARA (as low as reasonably achievable) philosophy

  4. The passive control of air pollution exposure in Dublin, Ireland: A combined measurement and modelling case study

    International Nuclear Information System (INIS)

    Gallagher, J.; Gill, L.W.; McNabola, A.

    2013-01-01

    This study investigates the potential real world application of passive control systems to reduce personal pollutant exposure in an urban street canyon in Dublin, Ireland. The implementation of parked cars and/or low boundary walls as a passive control system has been shown to minimise personal exposure to pollutants on footpaths in previous investigations. However, previous research has been limited to generic numerical modelling studies. This study combines real-time traffic data, meteorological conditions and pollution concentrations, in a real world urban street canyon before and after the implementation of a passive control system. Using a combination of field measurements and numerical modelling this study assessed the potential impact of passive controls on personal exposure to nitric oxide (NO) concentrations in the street canyon in winter conditions. A calibrated numerical model of the urban street canyon was developed, taking into account the variability in traffic and meteorological conditions. The modelling system combined the computational fluid dynamic (CFD) simulations and a semi-empirical equation, and demonstrated a good agreement with measured field data collected in the street canyon. The results indicated that lane distribution, fleet composition and vehicular turbulence all affected pollutant dispersion, in addition to the canyon geometry and local meteorological conditions. The introduction of passive controls displayed mixed results for improvements in air quality on the footpaths for different wind and traffic conditions. Parked cars demonstrated the most comprehensive passive control system with average improvements in air quality of up to 15% on the footpaths. This study highlights the potential of passive controls in a real street canyon to increase dispersion and improve air quality at street level. - Highlights: • Parked cars and LBWs were assessed as passive controls in an urban street canyon. • The calibrated model combined CFD

  5. The passive control of air pollution exposure in Dublin, Ireland: A combined measurement and modelling case study

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, J., E-mail: j.gallagher@bangor.ac.uk [School of Energy, Natural Resources and Geography, Bangor University (United Kingdom); Gill, L.W.; McNabola, A. [Dept. of Civil, Structural and Environmental Engineering, Trinity College Dublin (Ireland)

    2013-08-01

    This study investigates the potential real world application of passive control systems to reduce personal pollutant exposure in an urban street canyon in Dublin, Ireland. The implementation of parked cars and/or low boundary walls as a passive control system has been shown to minimise personal exposure to pollutants on footpaths in previous investigations. However, previous research has been limited to generic numerical modelling studies. This study combines real-time traffic data, meteorological conditions and pollution concentrations, in a real world urban street canyon before and after the implementation of a passive control system. Using a combination of field measurements and numerical modelling this study assessed the potential impact of passive controls on personal exposure to nitric oxide (NO) concentrations in the street canyon in winter conditions. A calibrated numerical model of the urban street canyon was developed, taking into account the variability in traffic and meteorological conditions. The modelling system combined the computational fluid dynamic (CFD) simulations and a semi-empirical equation, and demonstrated a good agreement with measured field data collected in the street canyon. The results indicated that lane distribution, fleet composition and vehicular turbulence all affected pollutant dispersion, in addition to the canyon geometry and local meteorological conditions. The introduction of passive controls displayed mixed results for improvements in air quality on the footpaths for different wind and traffic conditions. Parked cars demonstrated the most comprehensive passive control system with average improvements in air quality of up to 15% on the footpaths. This study highlights the potential of passive controls in a real street canyon to increase dispersion and improve air quality at street level. - Highlights: • Parked cars and LBWs were assessed as passive controls in an urban street canyon. • The calibrated model combined CFD

  6. Marine litter in submarine canyons of the Bay of Biscay

    Science.gov (United States)

    van den Beld, Inge M. J.; Guillaumont, Brigitte; Menot, Lénaïck; Bayle, Christophe; Arnaud-Haond, Sophie; Bourillet, Jean-François

    2017-11-01

    Marine litter is a matter of increasing concern worldwide, from shallow seas to the open ocean and from beaches to the deep-seafloor. Indeed, the deep sea may be the ultimate repository of a large proportion of litter in the ocean. We used footage acquired with a Remotely Operated Vehicle (ROV) and a towed camera to investigate the distribution and composition of litter in the submarine canyons of the Bay of Biscay. This bay contains many submarine canyons housing Vulnerable Marine Ecosystems (VMEs) such as scleractinian coral habitats. VMEs are considered to be important for fish and they increase the local biodiversity. The objectives of the study were to investigate and discuss: (i) litter density, (ii) the principal sources of litter, (iii) the influence of environmental factors on the distribution of litter, and (iv) the impact of litter on benthic communities. Litter was found in all 15 canyons and at three sites on the edge of the continental shelf/canyon, in 25 of 29 dives. The Belle-île and Arcachon Canyons contained the largest amounts of litter, up to 12.6 and 9.5 items per 100 images respectively. Plastic items were the most abundant (42%), followed by fishing-related items (16%). The litter had both a maritime and a terrestrial origin. The main sources could be linked to fishing activities, major shipping lanes and river discharges. Litter appeared to accumulate at water depths of 801-1100 m and 1401-1700 m. In the deeper of these two depth ranges, litter accumulated on a geologically structured area, accounting for its high frequency at this depth. A larger number of images taken in areas of coral in the shallower of these two depth ranges may account for the high frequency of litter detection at this depth. A larger number of litter items, including plastic objects in particular, were observed on geological structures and in coral areas than on areas of bare substratum. The distribution of fishing-related items was similar for the various types of

  7. 77 FR 9698 - Notice of Continuation of Visitor Services

    Science.gov (United States)

    2012-02-17

    ... National Parks. AMIS002-89 Lake Amistad Resort Amistad National and Marina, LLC. Recreation Area. AMIS003-87 Rough Canyon Amistad National Marina, LLC. Recreation Area. CACH001-84 White Dove, Inc., Canyon de...

  8. Late Quaternary evolution of the San Antonio Submarine Canyon in the central Chile forearc (∼33°S)

    Science.gov (United States)

    Laursen, Jane; Normark, William R.

    2002-01-01

    Hydrosweep swath-bathymetry and seismic-reflection data reveal the morphology, sedimentary processes, and structural controls on the submarine San Antonio Canyon. The canyon crosses the forearc slope of the central Chile margin for more than 150 km before it empties into the Chile Trench near 33°S latitude. In its upper reaches, the nearly orthogonal segments of the San Antonio Canyon incise ∼1 km into thick sediment following underlying margin-perpendicular basement faults and along the landward side of a prominent margin-parallel thrust ridge on the outer mid-slope. At a breach in the outer ridge, the canyon makes a sharp turn into the San Antonio Reentrant. Resistance to erosion of outcropping basement at the head of the reentrant has prevented the development of a uniformly sloping thalweg, leaving gentle gradients (6°) across the lower slope. Emergence of an obstruction across the head of the San Antonio Reentrant has trapped sediment in the mid-slope segments of the canyon. Presently, little sediment appears to reach the Chile Trench through the San Antonio Canyon. The development of the San Antonio Canyon was controlled by the impact of a subducted seamount, which formed the San Antonio Reentrant and warped the middle slope along its landward advancing path. Incision of the canyon landward of the outer mid-slope ridge may be ascribed to a combination of headward erosion and entrenchment by captured unconfined turbidity currents. Flushing of the canyon was likely enhanced during the lowered sea level of the last glaciation. Where the canyon occupies the triangular embayment of the reentrant at the base of the slope, sediment has ponded behind a small accretionary ridge. On the trench floor opposite the San Antonio Canyon mouth, a 200-m-thick levee–overbank complex formed on the left side of a distributary channel emanating from a breach in the accretionary ridge. Axial transfer of sediment was inhibited to the north of the San Antonio Canyon mouth

  9. Relationship between rooftop and on-road concentrations of traffic-related pollutants in a busy street canyon: Ambient wind effects

    International Nuclear Information System (INIS)

    Kwak, Kyung-Hwan; Lee, Sang-Hyun; Seo, Jaemyeong Mango; Park, Seung-Bu; Baik, Jong-Jin

    2016-01-01

    Rooftop and on-road measurements of O_3, NO_2, NO_x, and CO concentrations were conducted to investigate the relationship between rooftop and on-road concentrations in a busy and shallow street canyon with an aspect ratio of ∼0.3 in Seoul, Republic of Korea, from 15 April to 1 May 2014. The median road-to-roof concentration ratios, correlation coefficients between rooftop and on-road concentrations, and temporal variations of rooftop and on-road concentrations are analyzed according to the rooftop wind directions which are two cross-canyon and two along-canyon directions. The analysis results indicate that the relationship is strong when the rooftop is situated on the downwind side rather than on the upwind side. Relative to the cross-canyon wind directions, one of the along-canyon wind directions can more enhance the relationship. A conceptual framework is proposed to explain the effect of ambient wind direction on the relationship between rooftop and on-road concentrations in a street canyon. - One of the along-canyon wind directions can enhance the relationship between rooftop and on-road concentrations of traffic-related pollutants in a busy and shallow street canyon.

  10. The down canyon evolution of submarine sediment density flows

    Science.gov (United States)

    Parsons, D. R.; Barry, J.; Clare, M. A.; Cartigny, M.; Chaffey, M. R.; Gales, J. A.; Gwiazda, R.; Maier, K. L.; McGann, M.; Paull, C. K.; O'Reilly, T. C.; Rosenberger, K. J.; Simmons, S.; Sumner, E. J.; Talling, P.; Xu, J.

    2017-12-01

    Submarine density flows, known as turbidity currents, transfer globally significant volumes of terrestrial and shelf sediments, organic carbon, nutrients and fresher-water into the deep ocean. Understanding such flows has wide implications for global organic carbon cycling, the functioning of deep-sea ecosystems, seabed infrastructure hazard assessments, and interpreting geological archives of Earth history. Only river systems transport comparable volumes of sediment over such large areas of the globe. Despite their clear importance, there are remarkably few direct measurements of these oceanic turbidity currents in action. Here we present results from the multi-institution Coordinated Canyon Experiment (CCE) which deployed multiple moorings along the axis of Monterey Canyon (offshore California). An array of six moorings, with downward looking acoustic Doppler current profilers (ADCP) were positioned along the canyon axis from 290 m to 1850 m water depth. The ADCPs reveal the internal flow structure of submarine density flows at each site. We use a novel inversion method to reconstruct the suspended sediment concentration and flow stratification field during each event. Together the six moorings provide the first ever views of the internal structural evolution of turbidity current events as they evolve down system. Across the total 18-month period of deployment at least 15 submarine sediment density flows were measured with velocities up to 8.1 m/sec, with three of these flows extending 50 kms down the canyon beyond the 1850 m water depth mooring. We use these novel data to highlight the controls on ignition, interval structure and collapse of individual events and discuss the implications for the functioning and deposits produced by these enigmatic flows.

  11. Influence of roadside hedgerows on air quality in urban street canyons

    Science.gov (United States)

    Gromke, Christof; Jamarkattel, Nabaraj; Ruck, Bodo

    2016-08-01

    Understanding pollutant dispersion in the urban environment is an important aspect of providing solutions to reduce personal exposure to vehicle emissions. To this end, the dispersion of gaseous traffic pollutants in urban street canyons with roadside hedges was investigated. The study was performed in an atmospheric boundary layer wind tunnel using a reduced-scale (M = 1:150) canyon model with a street-width-to-building-height ratio of W/H = 2 and a street-length-to-building-height ratio of L/H = 10. Various hedge configurations of differing height, permeability and longitudinal segmentation (continuous over street length L or discontinuous with clearings) were investigated. Two arrangements were examined: (i) two eccentric hedgerows sidewise of the main traffic lanes and (ii) one central hedgerow between the main traffic lanes. In addition, selected configurations of low boundary walls, i.e. solid barriers, were examined. For a perpendicular approach wind and in the presence of continuous hedgerows, improvements in air quality in the center area of the street canyon were found in comparison to the hedge-free reference scenario. The pollutant reductions were greater for the central hedge arrangements than for the sidewise arrangements. Area-averaged reductions between 46 and 61% were observed at pedestrian head height level on the leeward side in front of the building for the centrally arranged hedges and between 18 and 39% for the two hedges arranged sidewise. Corresponding area-averaged reductions ranging from 39 to 55% and from 1 to 20% were found at the bottom of the building facades on the leeward side. Improvements were also found in the areas at the lateral canyon ends next to the crossings for the central hedge arrangements. For the sidewise arrangements, increases in traffic pollutants were generally observed. However, since the concentrations in the end areas were considerably lower compared to those in the center area, an overall improvement remained

  12. An Investigation of Amphitheater-Headed Canyon Distribution, Morphology Variation, and Longitudinal Profile Controls in Escalante and Tarantula Mesa, Utah.

    Science.gov (United States)

    Ryan, A. J.; Whipple, K. X.

    2014-12-01

    Amphitheater-headed canyons are primarily distinguished from typical fluvial channels by their abrupt headwall terminations. A key goal in the study of river canyons is to establish a reliable link between form and formation processes. This is of particular significance for Mars, where, if such links can be established, amphitheater-headed canyons could be used to determine ancient erosion mechanisms and, by inference, climate conditions. Type examples in arid regions on Earth, such as in Escalante River, Utah, previously have been interpreted as products of groundwater seepage erosion. We investigate amphitheater-headed canyons in Escalante and Tarantula Mesa where variations in canyon head morphology may hold clues for the relative roles of rock properties and fluvial and groundwater processes. In lower Escalante, amphitheaters are only present where canyons have breached the Navajo Sandstone - Kayenta Formation contact. In some canyons, amphitheater development appears to have been inhibited by an abundance of coarse bedload. In Tarantula Mesa, canyons have a variety of headwalls, from amphitheaters to stepped knickzones. Headwall morphology distribution is directly related to the spatially variable presence of knickpoint-forming, fine-grained interbeds within cliff-forming sandstones. Amphitheaters only form where the sandstone unit is undisrupted by these interbeds. Finally, most canyons in Escalante and Tarantula Mesa, regardless of substrate lithology, amphitheater presence, or groundwater spring intensity, are well described by a slope-area power law relationship with regionally constant concavity and normalized steepness indices. This suggests that all channels here are subject to the same erosion rates, independent of groundwater weathering intensity. Thus: 1) variations in canyon headwall form do not necessary relate to differences in fluvial history, 2) stratigraphic variations are clearly of importance in sedimentary canyon systems, and 3) although

  13. Effects of street canyon design on pedestrian thermal comfort in the hot-humid area of China.

    Science.gov (United States)

    Zhang, Yufeng; Du, Xiaohan; Shi, Yurong

    2017-08-01

    The design characteristics of street canyons were investigated in Guangzhou in the hot-humid area of China, and the effects of the design factors and their interactions on pedestrian thermal comfort were studied by numerical simulations. The ENVI-met V4.0 (BASIC) model was validated by field observations and used to simulate the micrometeorological conditions and the standard effective temperature (SET) at pedestrian level of the street canyons for a typical summer day of Guangzhou. The results show that the micrometeorological parameters of mean radiant temperature (MRT) and wind speed play key roles in pedestrian thermal comfort. Street orientation has the largest contribution on SET at pedestrian level, followed by aspect ratio and greenery, while surface albedo and interactions between factors have small contributions. The street canyons oriented southeast-northwest or with a higher aspect ratio provide more shade, higher wind speed, and better thermal comfort conditions for pedestrians. Compared with the east-west-oriented street canyons, the north-south-oriented street canyons have higher MRTs and worse pedestrian thermal comfort due to their wider building spacing along the street. The effects of greenery change with the road width and the time of the day. Street canyon design is recommended to improve pedestrian thermal comfort. This study provides a better understanding of the effects of street canyon design on pedestrian thermal comfort and is a useful guide on urban design for the hot-humid area of China.

  14. Structure-forming corals and sponges and their use as fish habitat in Bering Sea submarine canyons.

    Science.gov (United States)

    Miller, Robert J; Hocevar, John; Stone, Robert P; Fedorov, Dmitry V

    2012-01-01

    Continental margins are dynamic, heterogeneous settings that can include canyons, seamounts, and banks. Two of the largest canyons in the world, Zhemchug and Pribilof, cut into the edge of the continental shelf in the southeastern Bering Sea. Here currents and upwelling interact to produce a highly productive area, termed the Green Belt, that supports an abundance of fishes and squids as well as birds and marine mammals. We show that in some areas the floor of these canyons harbors high densities of gorgonian and pennatulacean corals and sponges, likely due to enhanced surface productivity, benthic currents and seafloor topography. Rockfishes, including the commercially important Pacific ocean perch, Sebastes alutus, were associated with corals and sponges as well as with isolated boulders. Sculpins, poachers and pleuronectid flounders were also associated with corals in Pribilof Canyon, where corals were most abundant. Fishes likely use corals and sponges as sources of vertical relief, which may harbor prey as well as provide shelter from predators. Boulders may be equivalent habitat in this regard, but are sparse in the canyons, strongly suggesting that biogenic structure is important fish habitat. Evidence of disturbance to the benthos from fishing activities was observed in these remote canyons. Bottom trawling and other benthic fishing gear has been shown to damage corals and sponges that may be very slow to recover from such disturbance. Regulation of these destructive practices is key to conservation of benthic habitats in these canyons and the ecosystem services they provide.

  15. Transport and deposition of plutonium-contaminated sediments by fluvial processes, Los Alamos Canyon, New Mexico

    International Nuclear Information System (INIS)

    Graf, W.L.

    1996-01-01

    Between 1945 and 1952 the development of nuclear weapons at Los Alamos National Laboratory, New Mexico, resulted in the disposal of plutonium into the alluvium of nearby Acid and (to a lesser degree) DP Canyons. The purpose of this paper is to explore the connection between the disposal sites and the main river, a 20 km link formed by the fluvial system of Acid, Pueblo, DP, and Los Alamos Canyons. Empirical data from 15 yr of annual sediment sampling throughout the canyon system has produced 458 observations of plutonium concentration in fluvial sediments. These data show that, overall, mean plutonium concentrations in fluvial sediment decline from 10,000 fCi/g near the disposal area to 100 fCi/g at the confluence of the canyon system and the Rio Grande. Simulations using a computer model for water, sediment, and plutonium routing in the canyon system show that discharges as large as the 25 yr event would fail to develop enough transport capacity to completely remove the contaminated sediments from Pueblo Canyon. Lesser flows would move some materials to the Rio Grande by remobilization of stored sediments. The simulations also show that the deposits and their contaminants have a predictable geography because they occur where stream power is low, hydraulic resistance is high, and the geologic and/or geomorphic conditions provide enough space for storage. 38 refs., 13 figs., 1 tab

  16. Estimation of health damage due to emission of air pollutants by cars: the canyon effect

    Energy Technology Data Exchange (ETDEWEB)

    Spadaro, J.V. [Ecole des Mines, Centre d' Energetique, Paris, 75 (France); Rabl, A.

    1999-07-01

    Since current epidemiological evidence suggests that air pollution has harmful effects even at typical ambient concentrations and the dispersion is significant over hundreds to thousands of km, the estimation of total health damage involves consideration of local and regional effects. In recent years, several estimates have been published of health damage due to air pollution from cars, in particular by Delucchi et al of UC Davis and by the ExternE Project of the European Commission. To capture the geographic extent of pollutant dispersion, local and regional models have been used in combination. The present paper addresses a potentially significant contribution of the total damage, not yet taken into account in these studies: the increased concentration of pollutants inside urban street canyons. This canyon effect is appreciable only for primary pollutants, the time constants for the formation of secondary pollutants being long compared to the residence time in the canyon. We assumed linearity of incremental health impact with incremental concentration, in view of the lack of epidemiological evidence for no-effect thresholds or significant deviations from linearity at typical ambient concentrations; therefore, only long term average concentrations matter. We use the FLUENT software to model the dispersion inside a street canyon for a wide range of rectangular geometries and wind velocities. Our results suggest that the canyon effect is of marginal significance for total damages, the contribution of the canyon effect being roughly 10 to 20% of the total. The relative importance of the canyon effect is, of course, highly variable with local conditions; it could be much smaller but it is unlikely to add more than 100% to the flat terrain estimate. (Author)

  17. Colorado Canyons National Conservation Area 2003 visitor use survey: Completion report

    Science.gov (United States)

    Ponds, Phadrea; Gillette, Shana C.; Koontz, Lynne

    2004-01-01

    This report represents the analysis of research conducted by the U.S. Geological Survey (USGS) for the Bureau of Land Management (BLM). The purpose is to provide socio-economic and recreational use information that can be used in the development of a Resource Management Plan (RMP) for the Colorado Canyons National Conservation Area (CCNCA). The results reported here deal primarily with recreation-based activities in four areas: Kokopelli Loops, Rabbit Valley, Loma Boat Launch, and Devil’s Canyon.

  18. A concentration correction scheme for Lagrangian particle model and its application in street canyon air dispersion modelling

    Energy Technology Data Exchange (ETDEWEB)

    Jiyang Xia [Shanghai Jiao Tong University, Shanghai (China). Department of Engineering Mechanics; Leung, D.Y.C. [The University of Hong Kong (Hong Kong). Department of Mechanical Engineering

    2001-07-01

    Pollutant dispersion in street canyons with various configurations was simulated by discharging a large number of particles into the computation domain after developing a time-dependent wind field. Trajectory of the released particles was predicted using a Lagrangian particle model developed in an earlier study. A concentration correction scheme, based on the concept of 'visibility', was adopted for the Lagrangian particle model to correct the calculated pollutant concentration field in street canyons. The corrected concentrations compared favourably with those from wind tunnel experiments and a linear relationship between the computed concentrations and wind tunnel data were found. The developed model was then applied to four simulations to test for the suitability of the correction scheme and to study pollutant distribution in street canyons with different configurations. For those cases with obstacles presence in the computation domain, the correction scheme gives more reasonable results compared with the one without using it. Different flow regimes are observed in the street canyons, which depend on building configurations. A counter-clockwise rotating vortex may appear in a two-building case with wind flow from left to right, causing lower pollutant concentration at the leeward side of upstream building and higher concentration at the windward side of downstream building. On the other hand, a stable clockwise rotating vortex is formed in the street canyon with multiple identical buildings, resulting in poor natural ventilation in the street canyon. Moreover, particles emitted in the downstream canyon formed by buildings with large height-to-width ratios will be transported to upstream canyons. (author)

  19. Three Years of Experience of Wet Gas Allocation on Canyon Express

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Aditya; Hall, James; Letton, Winsor

    2005-07-01

    In September 2002, production was begun from the three fields that together form the Canyon Express System- King's Peak, Aconcagua, and Camden Hills. The 9 wells from these fields are connected to a pair of 12-inch flow lines carrying the commingled wet gas a distance of approximately 92 kilometers back to the Canyon Station platform for processing. At the 21st NSFMW in October 2003, an initial report was given on the status of Wet Gas Allocation for the Canyon Express project. As discussed in that paper, dual-differential, subsea wet gas meters were chosen for the task of allocating gas and liquids back to individual wells. However, since the gas from all three fields was very dry (Lockhart-Martinelli parameter less than 0.01) and because the operating pressures were quite high (250 bar), application of the dual-differential function of the meters yielded errors in both liquid and gas flow rates. Furthermore, as these problems were being uncovered, scale was beginning to collect inside some of the meters. Taken together, these problems produced system imbalances as great as 20%. To address the problems, one of the individual flow metering elements within each wet gas meter was chosen as the allocation meter, operating as a single-phase gas meter. After three years of operation of the Canyon Express Project, considerable experience has been accumulated. Since at the time it held the record for deep water hydrocarbon production, application of the technologies discussed here were challenging and required considerable flexibility. It is believed that the Canyon Express experiences will benefit future deep water flow metering projects. The knowledge acquired thus far is surveyed and summarized. The emphasis is on the technical aspects. (tk)

  20. Influence of local parameters on the dispersion of traffic-related pollutants within street canyons

    Science.gov (United States)

    Karra, Styliani; Malki-Epshtein, Liora; Martin Hyde Collaboration

    2011-11-01

    Ventilation within urban cities and street canyons and the associated air quality is a problem of increasing interest in the last decades. It is important for to minimise exposure of the population to traffic-related pollutants at street level. The residence time of pollutants within the street canyons depends on the meteorological conditions such as wind speed and direction, geometry layout and local parameters (position of traffic lane within the street). An experimental study was carried out to investigate the influence of traffic lane position on the dispersion of traffic-related pollutants within different street canyons geometries: symmetrical (equal building heights on both sides of the street), non-symmetrical (uniform building heights but lower on one side of the street) and heterogeneous (non-uniform building heights on both sides of the street) under constant meteorological conditions. Laboratory experiments were carried out within a water channel and simultaneous measurements of velocity field and concentration scalar levels within and above the street canyons using PIV and PLIF techniques. Traffic -related emissions were simulated using a line emission source. Two positions were examined for all street geometries: line emission source was placed in the centre of the street canyon; line emission source was placed off the centre of the street. TSI Incorporated.

  1. ACUMEN 2012: Atlantic Canyons Undersea Mapping Expeditions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Between February and August 2012, a team of NOAA and external partners will conduct a mapping ‘blitz’ focused on deepwater canyons off the northeastern...

  2. Implementation of ergonomics in the management of parking increasing the quality of living parking park in mall Robinson Denpasar city

    Science.gov (United States)

    Sutapa, I. K.; Sudiarsa, I. M.

    2018-01-01

    The problems that often arise in the area of Denpasar City mostly caused by parking problems at the centers of activities such as shopping centers. The problems that occur not only because of the large number of vehicles that parked but also the result of the condition of parking officers who have not received attention, there is no concern about the physical condition of parking attendants because doing night guard duty. To improve the quality of parking officer, ergonomic parking lot is improved through the application of appropriate technology with systemic, holistic, interdisciplinary and participatory approach. The general objective of the research is to know the implementation of ergonomics in parking management on the improvement of the quality of parking officer in Robinson shopping center. The indicator of the quality of the parking officer work is the decrease of musculoskeletal complaints, fatigue, workload, boredom and increasing work motivation. The study was conducted using the same subject design, involving 10 subjects as a simple random sample. Intervention is done by arrangement of ergonomic basement motorcycle parking. Measurements done before and after repair. Washing out (WO) for 14 days. The data obtained were analyzed descriptively, tested normality (shapirowilk) and homogeneity (Levene Test). For normal and homogeneous distribution data, different test with One Way Anova, different test between Period with Post Hoc. Normally distributed and non-homogeneous data, different test with Friedman Test, different test between periods using Wilcoxon test. Data were analyzed with significance level of 5%. The results showed that the implementation of ergonomic in the management of parking area of the court decreased musculoskeletal complaints by 15.10% (p management of the parking lot improves the quality of the parking officer work from: (1) decrease of musculoskeletal complaints, (2) decrease of melting rate, (3) decrease of parking workload

  3. Parks & benefits

    DEFF Research Database (Denmark)

    Brandt, Jesper; Christensen, Andreas Aagaard; Holmes, Esbern

    2011-01-01

    conservation. Increasing visitor flows and cuts in staff resources has put focus on the management of visitor carrying capacities and their relation to landscape structure and zoning. At the same time park authorities face falling public appropriations and receding focus on their conservation functions...... compared to recreation and settlement. The constant priority of the balancing of nature protection and economic utilization gives rise to various experience with land use and visitor management relevant for sustainable development also outside the parks. In European nature parks the handling of visitor...... carrying capacities related to Natura2000-sites and their included habitat type areas is a priority theme for the sustainable management of nature parks. A comparative analysis of conditions and initiatives related to visitor carrying capacities in 8 nature parks in the Baltic region has been carried out...

  4. iParking: An Intelligent Indoor Location-Based Smartphone Parking Service

    OpenAIRE

    Liu, Jingbin; Chen, Ruizhi; Chen, Yuwei; Pei, Ling; Chen, Liang

    2012-01-01

    Indoor positioning technologies have been widely studied with a number of solutions being proposed, yet substantial applications and services are still fairly primitive. Taking advantage of the emerging concept of the connected car, the popularity of smartphones and mobile Internet, and precise indoor locations, this study presents the development of a novel intelligent parking service called iParking. With the iParking service, multiple parties such as users, parking facilities and service p...

  5. 2013 Pacific Gas and Electric Diablo Canyon Power Plant (DCPP): San Simeon, CA Central Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Diablo Canyon Power Plant (DCPP) LiDAR and Imagery datasets are comprised of three separate LiDAR surveys: Diablo Canyon (2010), Los Osos (2011), and San Simeon...

  6. 2011 Pacific Gas and Electric Diablo Canyon Power Plant (DCPP): Los Osos, CA Central Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Diablo Canyon Power Plant (DCPP) LiDAR and Imagery datasets are comprised of three separate LiDAR surveys: Diablo Canyon (2010), Los Osos (2011), and San Simeon...

  7. Structure-forming corals and sponges and their use as fish habitat in Bering Sea submarine canyons.

    Directory of Open Access Journals (Sweden)

    Robert J Miller

    Full Text Available Continental margins are dynamic, heterogeneous settings that can include canyons, seamounts, and banks. Two of the largest canyons in the world, Zhemchug and Pribilof, cut into the edge of the continental shelf in the southeastern Bering Sea. Here currents and upwelling interact to produce a highly productive area, termed the Green Belt, that supports an abundance of fishes and squids as well as birds and marine mammals. We show that in some areas the floor of these canyons harbors high densities of gorgonian and pennatulacean corals and sponges, likely due to enhanced surface productivity, benthic currents and seafloor topography. Rockfishes, including the commercially important Pacific ocean perch, Sebastes alutus, were associated with corals and sponges as well as with isolated boulders. Sculpins, poachers and pleuronectid flounders were also associated with corals in Pribilof Canyon, where corals were most abundant. Fishes likely use corals and sponges as sources of vertical relief, which may harbor prey as well as provide shelter from predators. Boulders may be equivalent habitat in this regard, but are sparse in the canyons, strongly suggesting that biogenic structure is important fish habitat. Evidence of disturbance to the benthos from fishing activities was observed in these remote canyons. Bottom trawling and other benthic fishing gear has been shown to damage corals and sponges that may be very slow to recover from such disturbance. Regulation of these destructive practices is key to conservation of benthic habitats in these canyons and the ecosystem services they provide.

  8. Rose Canyon Sustainable Aquaculture Project, San Diego, CA

    Science.gov (United States)

    Documents related to EPA's preparation of an Environmental Assessment (EA) to analyze the potential impacts related to the issuance of a National Pollutant Discharge Elimination System (NPDES) permit for the Rose Canyon Sustainable Aquaculture Project.

  9. Food-web dynamics and isotopic niches in deep-sea communities residing in a submarine canyon and on the adjacent open slopes

    Science.gov (United States)

    Demopoulos, Amanda W.J.; McClain-Counts, Jennifer; Ross, Steve W.; Brooke, Sandra; Mienis, Furu

    2017-01-01

    Examination of food webs and trophic niches provide insights into organisms' functional ecology, yet few studies have examined trophodynamics within submarine canyons, where the interaction of canyon morphology and oceanography influences habitat provision and food deposition. Using stable isotope analysis and Bayesian ellipses, we documented deep-sea food-web structure and trophic niches in Baltimore Canyon and the adjacent open slopes in the US Mid-Atlantic Region. Results revealed isotopically diverse feeding groups, comprising approximately 5 trophic levels. Regression analysis indicated that consumer isotope data are structured by habitat (canyon vs. slope), feeding group, and depth. Benthic feeders were enriched in 13C and 15N relative to suspension feeders, consistent with consuming older, more refractory organic matter. In contrast, canyon suspension feeders had the largest and more distinct isotopic niche, indicating they consume an isotopically discrete food source, possibly fresher organic material. The wider isotopic niche observed for canyon consumers indicated the presence of feeding specialists and generalists. High dispersion in δ13C values for canyon consumers suggests that the isotopic composition of particulate organic matter changes, which is linked to depositional dynamics, resulting in discrete zones of organic matter accumulation or resuspension. Heterogeneity in habitat and food availability likely enhances trophic diversity in canyons. Given their abundance in the world's oceans, our results from Baltimore Canyon suggest that submarine canyons may represent important havens for trophic diversity.

  10. Calcareous nannoplankton and benthic foraminiferal assemblages from the Nazare Canyon (Portuguese continental margin): Preliminary results

    International Nuclear Information System (INIS)

    Guerreiro, C; Oliveira, A; Rodrigues, A; Rosa, F; Cachao, M; Fatela, F

    2009-01-01

    Submarine canyons are assumed to play an important role in oceanic/neritic circulation, marine productivity and sedimentary processes, acting as preferential conduits between the littoral and deep oceanic domain. Here we present first results of a comparative micropalaeontological study on calcareous nannoplankton and benthic foraminifera from surface sediments from the surroundings of the upper Nazare Canyon (Portuguese continental margin) and from the shelf north of the canyon. Regardless of the difficulty to distinguish taphonomical from (palaeo)ecological effects in such a complex and still poorly known marine system, the first results suggest that the canyon's hydro-sedimentary dynamic regime act as a prolongation of the shore/inner shelf hydrodynamic conditions towards west, preventing deposition and/or preservation of the smaller and fragile species of calcareous nannoplankton (e.g. E. huxleyi and G. ericsonii) and enhancing the record of the larger and more opportunistic ones (e.g. G. oceanica); and disturbing benthic foraminiferal productivity and/or diversity, or their preservation in the fossil record. Both calcareous nannoplankton and benthic foraminifera are more abundant off the canyon's domain, suggesting that its highly energetic thalweg conditions are probably filtering the fossil record in the sediment. Still, preliminary results suggest that the occurrence of persistent physical phenomena related with the canyon's morphology and proximity to the coast (e.g. solitary internal waves) may be locally promoting favourable conditions for calcareous nannoplankton, as shown by high values of nannoliths, chlorophyll a and 19' hexanoyloxyfucoxantine (unpublished data) north of the canyon's head. It is our goal to test this hypothesis in the near future by (a) studying multicore and surficial sediments from more recent surveys, and (b) calibrating the sediment results with water column data presently in process at the Institute of Oceanography (IO).

  11. Calcareous nannoplankton and benthic foraminiferal assemblages from the Nazare Canyon (Portuguese continental margin): Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Guerreiro, C; Oliveira, A; Rodrigues, A [Division of Marine Geology, Portuguese Hydrographic Institute (IH), Rua das Trinas 49, 1249-093 Lisboa (Portugal); Rosa, F [CIACOMAR, Algarve University, Av. 16 de Julho s/n 8700-311 Olhao (Portugal); Cachao, M; Fatela, F [Geology Center and Geology Department, FCUL, Bloco C6, 3o Piso, sala 6.3.57 Campo Grande 1749-016 Lisboa (Portugal)], E-mail: catarina.guerreiro@hidrografico.pt

    2009-01-01

    Submarine canyons are assumed to play an important role in oceanic/neritic circulation, marine productivity and sedimentary processes, acting as preferential conduits between the littoral and deep oceanic domain. Here we present first results of a comparative micropalaeontological study on calcareous nannoplankton and benthic foraminifera from surface sediments from the surroundings of the upper Nazare Canyon (Portuguese continental margin) and from the shelf north of the canyon. Regardless of the difficulty to distinguish taphonomical from (palaeo)ecological effects in such a complex and still poorly known marine system, the first results suggest that the canyon's hydro-sedimentary dynamic regime act as a prolongation of the shore/inner shelf hydrodynamic conditions towards west, preventing deposition and/or preservation of the smaller and fragile species of calcareous nannoplankton (e.g. E. huxleyi and G. ericsonii) and enhancing the record of the larger and more opportunistic ones (e.g. G. oceanica); and disturbing benthic foraminiferal productivity and/or diversity, or their preservation in the fossil record. Both calcareous nannoplankton and benthic foraminifera are more abundant off the canyon's domain, suggesting that its highly energetic thalweg conditions are probably filtering the fossil record in the sediment. Still, preliminary results suggest that the occurrence of persistent physical phenomena related with the canyon's morphology and proximity to the coast (e.g. solitary internal waves) may be locally promoting favourable conditions for calcareous nannoplankton, as shown by high values of nannoliths, chlorophyll a and 19' hexanoyloxyfucoxantine (unpublished data) north of the canyon's head. It is our goal to test this hypothesis in the near future by (a) studying multicore and surficial sediments from more recent surveys, and (b) calibrating the sediment results with water column data presently in process at the Institute of

  12. Long-term surveillance plan for the Burro Canyon disposal cell, Slick Rock, Colorado

    International Nuclear Information System (INIS)

    1998-05-01

    This long-term surveillance plan (LTSP) describes the US Department of Energy (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Burro Canyon disposal cell in San Miguel County, Colorado. The US Nuclear Regulatory Commission (NRC) developed regulations for the issuance of a general license for the custody and long-term care of UMTRA Project disposal sites in 10 CFR Part 40. The purpose of this general license is to ensure that the UMTRA Project disposal sites are cared for in a manner that protects the public health and safety and the environment. Before each disposal site is licensed, the NRC requires the DOE to submit a site-specific LTSP. The DOE prepared this LTSP to meet this requirement for the Burro Canyon disposal cell. The general license becomes effective when the NRC concurs with the DOE's determination that remedial action is complete at the Burro Canyon disposal cell and the NRC formally accepts this LTSP. Attachment 1 contains the concurrence letters from NRC. This LTSP describes the long-term surveillance program the DOE will implement to ensure that the Burro Canyon disposal cell performs as designed. The program is based on site inspections to identify threats to disposal cell integrity. Ground water monitoring will not be required at the Burro Canyon disposal cell because the ground water protection strategy is supplemental standards based on low yield from the uppermost aquifer

  13. Assessment of changes at Glen Canyon Dam

    International Nuclear Information System (INIS)

    Cherry, D.; McCoy, J.; Crandall, S.

    1991-01-01

    This paper describes the complexity associated with the assessment of financial impacts of proposed and actual short-term restrictions at Glen Canyon Dam. The reasons for these restrictions are discussed as well as the methods used to measure their financial impact to Western Area Power Administration

  14. Formation of Box Canyon, Idaho, by megaflood: implications for seepage erosion on Earth and Mars.

    Science.gov (United States)

    Lamb, Michael P; Dietrich, William E; Aciego, Sarah M; Depaolo, Donald J; Manga, Michael

    2008-05-23

    Amphitheater-headed canyons have been used as diagnostic indicators of erosion by groundwater seepage, which has important implications for landscape evolution on Earth and astrobiology on Mars. Of perhaps any canyon studied, Box Canyon, Idaho, most strongly meets the proposed morphologic criteria for groundwater sapping because it is incised into a basaltic plain with no drainage network upstream, and approximately 10 cubic meters per second of seepage emanates from its vertical headwall. However, sediment transport constraints, 4He and 14C dates, plunge pools, and scoured rock indicate that a megaflood (greater than 220 cubic meters per second) carved the canyon about 45,000 years ago. These results add to a growing recognition of Quaternary catastrophic flooding in the American northwest, and may imply that similar features on Mars also formed by floods rather than seepage erosion.

  15. 33 CFR 165.1155 - Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California.

    Science.gov (United States)

    2010-07-01

    ... Nuclear Power Plant, Avila Beach, California. 165.1155 Section 165.1155 Navigation and Navigable Waters... Coast Guard District § 165.1155 Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach... surface to bottom, within a 2,000 yard radius of Diablo Canyon Nuclear Power Plant centered at position 35...

  16. Parks, Place and Pedagogy - Education Partnerships with the National Park Service

    Science.gov (United States)

    Vye, E. C.; Rose, W. I.; Nash, B.; Klawiter, M.; Huntoon, J. E.; Engelmann, C. A.; Gochis, E. E.; MiTEP

    2011-12-01

    The Michigan Teaching Excellence Program (MITEP) is a multi-year program of teacher leadership development that empowers science teachers in Grand Rapids, Kalamazoo, and Jackson to lead their schools and districts through the process of improving science teaching and learning. A component of this program is facilitated through partnership between academia, K-12 educators, and the National Park Service (NPS) that aims to develop place-based education strategies that improve diversity and Earth Science literacy. This tangible education method draws upon both the sense of place that National Parks offer and the art of interpretation employed by the park service. Combined, these deepen cognitive process and provide a more diverse reflection of what place means and the processes behind shaping what we see. Our partnerships present participants the opportunity to intern in a Midwest national park for 3-8 weeks during their third year in the program. In summer 2011, eleven teachers from the Grand Rapids school district participated in this innovative way of learning and teaching Earth Science. One goal was to develop geological interpretive materials desired and needed for the parks. Secondly, and important to place-based educational methodologies, these deliverables will be used as a way of bringing the parks to urban classrooms. Participants lived in the parks and worked directly with both national park and Michigan Tech staff to create lesson plans, podcasts, media clips, video, and photographic documentation of their experiences. These lesson plans will be hosted in the Views of the National Park website in an effort to provide innovative teaching resources nationally for teachers or free-choice learners wishing to access information on Midwest national parks. To the benefit of park staff, working with teachers from urban areas offered an opportunity for park staff to access diverse learners in urban settings unable to visit the park. The foundation has been laid for

  17. Fluid mechanical dispersion of airborne pollutants inside urban street canyons subjecting to multi-component ventilation and unstable thermal stratifications.

    Science.gov (United States)

    Mei, Shuo-Jun; Liu, Cheng-Wei; Liu, Di; Zhao, Fu-Yun; Wang, Han-Qing; Li, Xiao-Hong

    2016-09-15

    The pedestrian level pollutant transport in street canyons with multiple aspect ratios (H/W) is numerically investigated in the present work, regarding of various unstable thermal stratification scenarios and plain surrounding. Non-isothermal turbulent wind flow, temperature field and pollutant spread within and above the street canyons are solved by the realizable k-ε turbulence model along with the enhanced wall treatment. One-vortex flow regime is observed for shallow canyons with H/W=0.5, whereas multi-vortex flow regime is observed for deep canyons with H/W=2.0. Both one-vortex and multi-vortex regimes could be observed for the street canyons with H/W=1.0, where the secondary vortex could be initiated by the flow separation and intensified by unstable thermal stratification. Air exchange rate (AER) and pollutant retention time are adopted to respectively evaluate the street canyon ventilation and pollutant removal performance. A second-order polynomial functional relationship is established between AER and Richardson number (Ri). Similar functional relationship could be established between retention time and Ri, and it is only valid for canyons with one-vortex flow regime. In addition, retention time could be prolonged abruptly for canyons with multi-vortex flow regime. Very weak secondary vortex is presented at the ground level of deep canyons with mild stratification, where pollutants are highly accumulated. However, with the decrease of Ri, pollutant concentration adjacent to the ground reduces accordingly. Present research could be applied to guide the urban design and city planning for enhancing pedestrian environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Seven years of geomorphic change in the head of Monterey Canyon, CA: Steady state equilibrium or monotonic change?

    Science.gov (United States)

    Smith, D. P.; Kvitek, R. G.; Ross, E.; Iampietro, P.; Paull, C. K.; Sandersfeld, M.

    2010-12-01

    The head of Monterey submarine canyon has been surveyed with high-precision multibeam sonar at least once each year since September 2002. This poster provides a summary of changes between September 2002 and September 2008. Data were collected with a variety of Reson mulitbeam sonar heads, and logged with an ISIS data acquisition system. Vessel attitude was corrected using an Applanix POS MV equipped with an auxillary C-Nav 2050 GPS receiver. Data were processed and filtered and cleaned in Caris HIPS. Depth changes for various time spans were determined through raster subtraction of pairs of 3-m resolution bathymetric grids in ArcMap. The depth change analyses focused on the canyon floor, except where a landslide occurred on a wall, and where obvious gullying near the headwall had occurred during the time of our study. Canyon walls were generally excluded from analysis. The analysis area was 1,414,240 sq meters. The gross changes between 2002 and 2008 include net erosion of 2,300,000 m^3 +/- 800,000 m^3 of material from the canyon. The annualized rate of net sediment loss from this time frame agrees within an order of magnitude with our previously published estimates from earlier (shorter) time frames, so the erosion events seem to be moderate magnitude and frequent, rather than infrequent and catastrophic. The greatest sediment loss appears to be from lateral erosion of channel-bounding terraces rather than deepening or scouring of the existing channel axis. A single landslide event that occurred in summer 2003 had an initial slide scar (void) volume of 71,000 m^3. The scar was observed to increase annually, and had grown to approximately 96,000 m^3 by 2008. The initial slide was too small to be tsunamigenic. In contrast to the monotonic canyon axis widening, the shoreward terminus of the canyon (canyon lip) appears to be in steady state equilibrium with sediment supply entering the canyon from the littoral zone. The lip position, indicated by the clearly defined

  19. Simulations of the impacts of building height layout on air quality in natural-ventilated rooms around street canyons.

    Science.gov (United States)

    Yang, Fang; Zhong, Ke; Chen, Yonghang; Kang, Yanming

    2017-10-01

    Numerical simulations were conducted to investigate the effects of building height ratio (i.e., HR, the height ratio of the upstream building to the downstream building) on the air quality in buildings beside street canyons, and both regular and staggered canyons were considered for the simulations. The results show that the building height ratio affects not only the ventilation fluxes of the rooms in the downstream building but also the pollutant concentrations around the building. The parameter, outdoor effective source intensity of a room, is then proposed to calculate the amount of vehicular pollutants that enters into building rooms. Smaller value of this parameter indicates less pollutant enters the room. The numerical results reveal that HRs from 2/7 to 7/2 are the favorable height ratios for the regular canyons, as they obtain smaller values than the other cases. While HR values of 5/7, 7/7, and 7/5 are appropriate for staggered canyons. In addition, in terms of improving indoor air quality by natural ventilation, the staggered canyons with favorable HR are better than those of the regular canyons.

  20. Determining the flux of methane into Hudson Canyon at the edge of methane clathrate hydrate stability

    Science.gov (United States)

    Weinsten, A.; Navarrete, L; Ruppel, Carolyn D.; Weber, T.C.; Leonte, M.; Kellermann, M.; Arrington, E.; Valentine, D.L.; Scranton, M.L; Kessler, John D.

    2016-01-01

    Methane seeps were investigated in Hudson Canyon, the largest shelf-break canyon on the northern US Atlantic Margin. The seeps investigated are located at or updip of the nominal limit of methane clathrate hydrate stability. The acoustic identification of bubble streams was used to guide water column sampling in a 32 km2 region within the canyon's thalweg. By incorporating measurements of dissolved methane concentration with methane oxidation rates and current velocity into a steady-state box model, the total emission of methane to the water column in this region was estimated to be 12 kmol methane per day (range: 6 – 24 kmol methane per day). These analyses suggest this methane is largely retained inside the canyon walls below 300 m water depth, and that it is aerobically oxidized to near completion within the larger extent of Hudson Canyon. Based on estimated methane emissions and measured oxidation rates, the oxidation of this methane to dissolved CO2 is expected to have minimal influences on seawater pH. This article is protected by copyright. All rights reserved.

  1. UV Radiation in an Urban Canyon in Southeast Queensland

    Science.gov (United States)

    McKinley, A. R.; Moore, M. R.; Kimlin, M. G.

    2006-12-01

    Ultraviolet radiation (UV) has the possibility to both harm and to benefit human beings when unprotected exposure occurs. After receiving small amounts of UV our bodies begin to synthesise vitamin D, which is essential for maintaining healthy bones, however excessive UV exposure can result in a variety of damaging outcomes ranging from sunburn to skin cancer and cataracts. For this reason it is very important to understand the different environments in which people encounter UV so as to better prepare the public to make smart and healthy sun exposure decisions. Each day more and more people are moving into large cities around the world and spending their time inside the urban canyon, however UV measurements are generally taken at scientific stations in open areas or on top of tall buildings, meaning that at times the environmental characteristics measured may not accurately represent those found at street-level in these highly urbanized areas. Urban canyons are home to both very tall buildings and tropospheric air pollution, each of which reduces the amount of UV reaching street-level. This study measured the varying difference between UV measurements taken at street-level and at a standard UV monitoring site on top of a building outside of the urban canyon. Investigation was conducted in the central business district (CBD) of Brisbane, Australia, which models the CBDs of large cities around the world in that it boasts a great number of tall buildings, including many skyscrapers. Data was collected under clear sky conditions at five different street-level sites in the CBD (on either side of two streets running perpendicular to one another (four sites) and in a public square) and then compared to that obtained on the same day at the Queensland University of Technology's Australian Sun and Health Research Laboratory (ASHRL), which is located 2.5 kilometres outside Brisbane's CBD. Minimum erythemal dose (MED) data was collected at each location and it was found that

  2. Effects of trees on the dilution of vehicle exhaust emissions in urban street canyons

    NARCIS (Netherlands)

    Gromke, C.B.; Ruck, B.

    2009-01-01

    In order to investigate the natural ventilation and air quality of urban street canyons with trees, boundary layer wind tunnel studies at a small-scale model have been performed. Concentrations in street canyons with a tracer gas emitting line source at the ground level and one row of trees arranged

  3. Influence of Parking Price on Parking Garage Users’ Behaviour

    Directory of Open Access Journals (Sweden)

    Jelena Simićević

    2012-09-01

    Full Text Available Parking charge is a powerful tool for solving parking and traffic congestion problems. In order to achieve the expected effects without any adverse impact it is necessary to understand well the users’ responses to this policy. This paper, based on a sample of interviewed parking garage users, has developed binary logit model for identification and quantification of characteristics of users and trips, on which the acceptance of parking price is dependent. In addition, multinomial logit model has been made in order to predict what the users will opt for when faced with an increase in parking price. For the first time the parameter “shorten duration” has been introduced which has shown to be the most significant in making behaviour-related decisions. The results show that the users with the purpose work are the most sensitive to an increase in parking charge, what can be deemed positive for policy makers. However, great sensitivity of the users with the purpose shopping should cause their concern. The results of the multinomial model show that they would not discontinue coming into the area after all.

  4. Mathematical model of parking space unit for triangular parking area

    Science.gov (United States)

    Syahrini, Intan; Sundari, Teti; Iskandar, Taufiq; Halfiani, Vera; Munzir, Said; Ramli, Marwan

    2018-01-01

    Parking space unit (PSU) is an effective measure for the area size of a vehicle, including the free space and the width of the door opening of the vehicle (car). This article discusses a mathematical model for parking space of vehicles in triangular shape area. An optimization model for triangular parking lot is developed. Integer Linear Programming (ILP) method is used to determine the maximum number of the PSU. The triangular parking lot is in isosceles and equilateral triangles shape and implements four possible rows and five possible angles for each field. The vehicles which are considered are cars and motorcycles. The results show that the isosceles triangular parking area has 218 units of optimal PSU, which are 84 units of PSU for cars and 134 units of PSU for motorcycles. Equilateral triangular parking area has 688 units of optimal PSU, which are 175 units of PSU for cars and 513 units of PSU for motorcycles.

  5. Perspective view over the Grand Canyon, Arizona

    Science.gov (United States)

    2001-01-01

    This simulated true color perspective view over the Grand Canyon was created from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data acquired on May 12, 2000. The Grand Canyon Village is in the lower foreground; the Bright Angel Trail crosses the Tonto Platform, before dropping down to the Colorado Village and then to the Phantom Ranch (green area across the river). Bright Angel Canyon and the North Rim dominate the view. At the top center of the image the dark blue area with light blue haze is an active forest fire. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Size: 5 km in foreground to 40 km Location: 36.3 degrees north latitude, 112 degrees west longitude Orientation: North-northeast at top Original Data Resolution: ASTER 15 meters Dates Acquired: May 12, 2000

  6. A numerical study of air pollutant dispersion with bimolecular chemical reactions in an urban street canyon using large-eddy simulation

    Science.gov (United States)

    Kikumoto, Hideki; Ooka, Ryozo

    2012-07-01

    A large-eddy simulation is performed on a turbulent dispersion of chemically reactive air pollutants in a two-dimensional urban street canyon with an aspect ratio of 1.0. Nitrogen monoxide emitted from a line-source set on the bottom of the street canyon disperses and reacts with Ozone included in a free stream. The reactions have significant influences on the concentrations of pollutants in the canyon space, and they increase the concentrations of the reaction products relative to of the concentrations of the reactants. The transport of air pollutants through a free shear layer above the canyon is closely related to the structure of the turbulence. Gases in the canyon are mainly exhausted when low-speed regions appear above the canyon. In contrast, pollutants in the free stream flow into the canyon with high-speed fluid bodies. Consequently, the correlation between the time fluctuations of the reactants' concentrations strongly affects the reaction rates in the region near the free shear layer. In this calculation, the correlation term reaches to a value of 20% of the mean reaction rate at a maximum there.

  7. Numerical modeling of flow and pollutant dispersion in street canyons with tree planting

    Energy Technology Data Exchange (ETDEWEB)

    Balczo, Marton [Budapest Univ. of Technology and Economics (Hungary). Theodore von Karman Wind Tunnel Lab.; Gromke, Christof; Ruck, Bodo [Karlsruhe Univ. (Germany). Lab. of Building- and Environmental Aerodynamics

    2009-04-15

    Numerical simulations of the impact of tree planting on airflow and traffic pollutant dispersion in urban street canyons have been performed using the commercial CFD (Computational Fluid Dynamics) code MISKAM. A {kappa}-{epsilon} turbulence model including additional terms for the treatment of vegetation, has been employed to close the Reynolds-averaged-Navier-Stokes (RANS) equations. The numerical results were compared to wind tunnel data. In the case of the investigated wind direction perpendicular to the street axis, the presence of trees lead to increased pollutant concentrations inside the canyon. Concentrations increased strongly on the upstream side of the canyon, while on the downstream side a small concentration decrease could be observed. Lower flow velocities and higher pollutant concentrations were found in the numerical simulations when directly compared to the experimental results. However, the impact of tree planting on airflow and concentration fields when compared to the treeless street canyon as a reference configuration were simulated quite well, meaning that relative changes were similar in the wind tunnel investigations and numerical computations. This feature qualifies MISKAM for use as a tool for assessing the impacts of vegetation on local air quality. (orig.)

  8. Evaluating urban parking policies with agent-based model of driver parking behavior

    NARCIS (Netherlands)

    Martens, C.J.C.M.; Benenson, I.

    2008-01-01

    This paper presents an explicit agent-based model of parking search in a city. In the model, “drivers” drive toward their destination, search for parking, park, remain at the parking place, and leave. The city’s infrastructure is represented by a high-resolution geographic information system (GIS)

  9. Analysis on Time Window of Shared Parking in Hospitals Based on Parking Behaviors

    Directory of Open Access Journals (Sweden)

    Qin Chen

    2017-01-01

    Full Text Available Hospitals are essential components of a city; huge traffic demand is generated and attracted, causing contradiction between parking supply and demand. By sharing parking berths, limited space can serve more demand which is beneficial to alleviating parking problems. Aimed at improving the capacity of shared parking, the paper analyzes four parking groups in typical hospitals, which are medical staff, outpatients, emergency patients, and visiting groups. The parking demand of medical staff is rigid. For outpatients and visiting groups, longer walking distance is acceptable and more attention is paid to parking fee. By contrast, emergency patients can accept shorter walking distance and focus more on convenience due to urgency. Under this circumstance, parking behaviors selection models are established by means of Multinomial Logit Model. On this basis, time value is adopted to calculate the tolerance of alterative parking time. Moreover, this paper explores the variation of time window, under different parking impedance. A case study is conducted and suggests that start and end point of a certain time window can be influenced by external factors.

  10. 75 FR 26788 - Public Land Order No. 7742; Withdrawal of Public Land for the Manning Canyon Tailings Repository; UT

    Science.gov (United States)

    2010-05-12

    ... 79765] Public Land Order No. 7742; Withdrawal of Public Land for the Manning Canyon Tailings Repository... period of 5 years to protect the integrity of the Manning Canyon Tailings Repository and surrounding... withdrawal is to protect public health and safety and the Federal investment in the Manning Canyon Tailings...

  11. A simple model for calculating air pollution within street canyons

    Science.gov (United States)

    Venegas, Laura E.; Mazzeo, Nicolás A.; Dezzutti, Mariana C.

    2014-04-01

    This paper introduces the Semi-Empirical Urban Street (SEUS) model. SEUS is a simple mathematical model based on the scaling of air pollution concentration inside street canyons employing the emission rate, the width of the canyon, the dispersive velocity scale and the background concentration. Dispersive velocity scale depends on turbulent motions related to wind and traffic. The parameterisations of these turbulent motions include two dimensionless empirical parameters. Functional forms of these parameters have been obtained from full scale data measured in street canyons at four European cities. The sensitivity of SEUS model is studied analytically. Results show that relative errors in the evaluation of the two dimensionless empirical parameters have less influence on model uncertainties than uncertainties in other input variables. The model estimates NO2 concentrations using a simple photochemistry scheme. SEUS is applied to estimate NOx and NO2 hourly concentrations in an irregular and busy street canyon in the city of Buenos Aires. The statistical evaluation of results shows that there is a good agreement between estimated and observed hourly concentrations (e.g. fractional bias are -10.3% for NOx and +7.8% for NO2). The agreement between the estimated and observed values has also been analysed in terms of its dependence on wind speed and direction. The model shows a better performance for wind speeds >2 m s-1 than for lower wind speeds and for leeward situations than for others. No significant discrepancies have been found between the results of the proposed model and that of a widely used operational dispersion model (OSPM), both using the same input information.

  12. Radiochemical quality of water in the shallow aquifer in Mortandad Canyon, 1967-1978

    International Nuclear Information System (INIS)

    Purtymun, W.D.; Hansen, W.R.; Peters, R.J.

    1983-03-01

    Mortandad Canyon receives treated industrial liquid effluents that contain trace amounts of radionuclides. The effluents, other waste water, and storm runoff recharge a shallow aquifer in the alluvium of the canyon. The aquifer lies within the Los Alamos National Laboratory boundaries. Analyses for gross alpha, gross beta, 137 Cs, 238 Pu, 239 Pu, 241 Am, 90 Sr, 3 H, and total U have been made of water in the aquifer from 1967 through 1978. Average concentrations of the radionuclides in solution decrease downgradient in the canyon with the exception of 3 H. Average 3 H concentrations were highest in the Middle Canyon. Inventories of most radionuclides in the water indicate that in 1978 less than 1% of the total amount released with the effluents in the canyon from 1963 through 1978 remained in solution. The amount of total U in solution in 1978 was about 16% of the total amount released. If there is no significant change in the amounts of radionuclides received at the treatment plant and methods of treatment remain the same, the projected estimates of radionuclide concentrations in the aquifer will increase about 80% from 1978 to 1990. The average concentrations in 1978 and projected concentrations in 1990 of gross alpha, 137 Cs, 238 Pu, 239 Pu, 241 Am, 90 Sr, 3 H, and total U are less than 1% of the Department of Energy's concentration guides (CG) for areas with controlled public access. Gross beta radioactivity in 1978 was 2% of the CG and is projected to increase to 3% of the CG by 1990

  13. Mortandad Canyon: Elemental concentrations in vegetation, streambank soils, and stream sediments - 1979

    International Nuclear Information System (INIS)

    Ferenbaugh, R.W.; Gladney, E.S.

    1997-06-01

    In 1979, stream sediments, streambank soils, and streambank vegetation were sampled at 100 m intervals downstream of the outfall of the TA-50 radioactive liquid waste treatment facility in Mortandad Canyon. Sampling was discontinued at a distance of 3260 m at the location of the sediment traps in the canyon. The purpose of the sampling was to investigate the effect of the residual contaminants in the waste treatment facility effluent on elemental concentrations in various environmental media

  14. Structural character of the northern segment of the Paintbrush Canyon fault, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Dickerson, R.P.; Spengler, R.W.

    1994-01-01

    Detailed mapping of exposed features along the northern part of the Paintbrush Canyon fault was initiated to aid in construction of the computer-assisted three-dimensional lithostratigraphic model of Yucca Mountain, to contribute to kinematic reconstruction of the tectonic history of the Paintbrush Canyon fault, and to assist in the interpretation of geophysical data from Midway Valley. Yucca Mountain is segmented into relatively intact blocks of east-dipping Miocene volcanic strata, bounded by north-striking, west-dipping high-angle normal faults. The Paintbrush Canyon fault, representing the easternmost block-bounding normal fault, separates Fran Ridge from Midway Valley and continues northward across Yucca Wash to at least the southern margin of the Timber Mountain Caldera complex. South of Yucca Wash, the Paintbrush Canyon Fault is largely concealed beneath thick Quaternary deposits. Bedrock exposures to the north reveal a complex fault, zone, displaying local north- and west-trending grabens, and rhombic pull-apart features. The fault scarp, discontinuously exposed along a mapped length of 8 km north of Yucca Wash, dips westward by 41 degrees to 74 degrees. Maximum vertical offset of the Rhyolite of Comb Peak along the fault measures about 210 m in Paintbrush Canyon and, on the basis of drill hole information, vertical offset of the Topopoah Spring Tuff is about 360 m near the northern part of Fran Ridge. Observed displacement along the fault in Paintbrush Canyon is down to the west with a component of left-lateral oblique slip. Unlike previously proposed tectonic models, strata adjacent to the fault dip to the east. Quaternary deposits do not appear displaced along the fault scarp north of Yucca Wash, but are displaced in trenches south of Yucca Wash

  15. 76 FR 14745 - Notice To Rescind a Notice of Intent To Prepare an Environmental Impact Statement, Ada and Canyon...

    Science.gov (United States)

    2011-03-17

    ... To Prepare an Environmental Impact Statement, Ada and Canyon Counties, ID AGENCY: Federal Highway... prepare an Environmental Impact Statement for a proposed highway project in Ada and Canyon County, Idaho... Highway 44 from Exit 25 at Interstate 84 in Canyon County to Ballantyne Lane in Ada County. The project is...

  16. Effects of Building‒roof Cooling on Flow and Distribution of Reactive Pollutants in street canyons

    Science.gov (United States)

    Park, S. J.; Choi, W.; Kim, J.; Jeong, J. H.

    2016-12-01

    The effects of building‒roof cooling on flow and dispersion of reactive pollutants were investigated in the framework of flow dynamics and chemistry using a coupled CFD‒chemistry model. For this, flow characteristics were analyzed first in street canyons in the presence of building‒roof cooling. A portal vortex was generated in street canyon, producing dominant reverse and outward flows near the ground in all the cases. The building‒roof cooling increased horizontal wind speeds at the building roof and strengthened the downward motion near the downwind building in the street canyon, resultantly intensifying street canyon vortex strength. The flow affected the distribution of primary and secondary pollutants. Concentrations of primary pollutants such as NOx, VOC and CO was high near the upwind building because the reverse flows were dominant at street level, making this area the downwind region of emission sources. Concentration of secondary pollutant such as O3 was lower than the background near the ground, where NOX concentrations were high. Building‒roof cooling decreased the concentration of primary pollutants in contrasted to those under non‒cooling conditions. In contrast, building‒roof cooling increased O3 by reducing NO concentrations in urban street canyon compared to concentrations under non‒cooling conditions.

  17. Direct sampling during multiple sediment density flows reveals dynamic sediment transport and depositional environment in Monterey submarine canyon

    Science.gov (United States)

    Maier, K. L.; Gales, J. A.; Paull, C. K.; Gwiazda, R.; Rosenberger, K. J.; McGann, M.; Lundsten, E. M.; Anderson, K.; Talling, P.; Xu, J.; Parsons, D. R.; Barry, J.; Simmons, S.; Clare, M. A.; Carvajal, C.; Wolfson-Schwehr, M.; Sumner, E.; Cartigny, M.

    2017-12-01

    Sediment density flows were directly sampled with a coupled sediment trap-ADCP-instrument mooring array to evaluate the character and frequency of turbidity current events through Monterey Canyon, offshore California. This novel experiment aimed to provide links between globally significant sediment density flow processes and their resulting deposits. Eight to ten Anderson sediment traps were repeatedly deployed at 10 to 300 meters above the seafloor on six moorings anchored at 290 to 1850 meters water depth in the Monterey Canyon axial channel during 6-month deployments (October 2015 - April 2017). Anderson sediment traps include a funnel and intervalometer (discs released at set time intervals) above a meter-long tube, which preserves fine-scale stratigraphy and chronology. Photographs, multi-sensor logs, CT scans, and grain size analyses reveal layers from multiple sediment density flow events that carried sediment ranging from fine sand to granules. More sediment accumulation from sediment density flows, and from between flows, occurred in the upper canyon ( 300 - 800 m water depth) compared to the lower canyon ( 1300 - 1850 m water depth). Sediment accumulated in the traps during sediment density flows is sandy and becomes finer down-canyon. In the lower canyon where sediment directly sampled from density flows are clearly distinguished within the trap tubes, sands have sharp basal contacts, normal grading, and muddy tops that exhibit late-stage pulses. In at least two of the sediment density flows, the simultaneous low velocity and high backscatter measured by the ADCPs suggest that the trap only captured the collapsing end of a sediment density flow event. In the upper canyon, accumulation between sediment density flow events is twice as fast compared to the lower canyon; it is characterized by sub-cm-scale layers in muddy sediment that appear to have accumulated with daily to sub-daily frequency, likely related to known internal tidal dynamics also measured

  18. Safety analysis, 200 Area, Savannah River Plant H-Canyon operations. Supplement 5

    Energy Technology Data Exchange (ETDEWEB)

    Beary, M M; Collier, C D; Fairobent, L A; Graham, R F; Mason, C L; McDuffee, W T; Owen, T L; Walker, D H [Science Applications International Corp., San Diego, CA (United States)

    1986-02-01

    The H-Canyon facility is located in the 200 Separations Area and uses the HM process to separate uranium, neptunium, plutonium, and fission products. Irradiated uranium fuels containing {sup 235}U at enrichments from 1.1% to 94% are processed and recovered, along with neptunium and plutonium isotopes. This Safety Analysis Report (SAR) documents an analysis of the H-Canyon operations and is an update to a section of a previous SAR. This SAR documents an analysis of the H-Canyon and is one of a series of documents for the Separations Area as specified in the Savannah River Implementation Plans. A substantial amount of the information supporting the Conclusions of this SAR is found in the Systems Analysis. Some H-Canyon equipment has been updated during the time between the Systems Analysis and this SAR and a complete description of this equipment is included in this report. The primary purpose of the analysis was to demonstrate that the H-Carbon can be operated without due risk to onsite or offsite populations and to the environment. In this report, risk is defined an the expected frequency of an accident, multiplied by the resulting radiological consequence in person-rem. The units of risk for radiological does are person-rem/year. Maximum individual exposure values have also been calculated and reported.

  19. SMART VEHICLE PARKING

    OpenAIRE

    S.Bharath Ram

    2016-01-01

    The goal of this project is to count the number of empty car parking areas and to display them in a Website. This system consists of sensors attached to several parking areas. These sensors located in different parking area’s detects the presence of vehicle and sends information to Microcontroller, which calculates the number of available empty parking areas and uploads them in a website. This basically works on the principle of Internet of Things here the sensors are connected to internet.

  20. Operational Readiness Review Final Report For F-Canyon Restart. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, A.F.; Spangler, J.B.

    1995-04-05

    An independent WSRC Operational Readiness Review was performed for the restart of Phase 1 processing in F-Canyon, Building 221-F. Readiness to restart the Second Plutonium Cycle process and solvent recovery was assessed. The ORR was conducted by an ORR board of ten members with the support of a subject matter expert. The chairman and four members were drawn from the Operational Safety Evaluation Department, ESH& QA Division; additional members were drawn from other WSRC divisions, independent of the F-Canyon operating division (NMPD). Based on the results of the readiness verification assessments performed according to the ORR plan and the validation of pre-restart corrective actions, the WSRC independent ORR Board has concluded that the facility has achieved the state of readiness committed to in the Restart Plan. Also, based on the scope of the ORR, it is the opinion of the board that F-Canyon Phase 1 processes can be restarted without undue risk to the safety of the public and onsite workers and without undue risk to the environment.

  1. Operational Readiness Review Final Report For F-Canyon Restart. Phase 1

    International Nuclear Information System (INIS)

    McFarlane, A.F.; Spangler, J.B.

    1995-01-01

    An independent WSRC Operational Readiness Review was performed for the restart of Phase 1 processing in F-Canyon, Building 221-F. Readiness to restart the Second Plutonium Cycle process and solvent recovery was assessed. The ORR was conducted by an ORR board of ten members with the support of a subject matter expert. The chairman and four members were drawn from the Operational Safety Evaluation Department, ESH ampersand QA Division; additional members were drawn from other WSRC divisions, independent of the F-Canyon operating division (NMPD). Based on the results of the readiness verification assessments performed according to the ORR plan and the validation of pre-restart corrective actions, the WSRC independent ORR Board has concluded that the facility has achieved the state of readiness committed to in the Restart Plan. Also, based on the scope of the ORR, it is the opinion of the board that F-Canyon Phase 1 processes can be restarted without undue risk to the safety of the public and onsite workers and without undue risk to the environment

  2. A Numerical Study on Characteristics of Flow and Reactive Pollutant Dispersion in Step‒up Street Canyons

    Science.gov (United States)

    Kim, E. R.; Kim, J.

    2014-12-01

    For decades, many metro‒ and/or mega‒cities have grown and densities of population and building have increased. Because pollutants released from sources near ground surface such as vehicles are not easy to escape from street canyons which are spaces between buildings standing along streets pedestrians, drivers and residents are likely to be exposed to high concentrations of hazardous pollutants. Therefore, it is important to understand characteristics of flow and pollutant dispersion in street canyons. In this study, step‒up street canyons with higher downwind buildings are considered for understanding flow and reactive pollutants' dispersion characteristics there as a basic step to understand the characteristics in wider urban areas. This study used a CFD model coupled to a chemistry module. Detailed flow and air pollutant concentration are analyzed in step‒up street canyons with different upwind building heights.

  3. Capacity Analysis Of Parking Lot And Volume Of Vehicle Toward Sustainable Parking Convenience

    Science.gov (United States)

    Herdiansyah, Herdis; Sugiyanto; Guntur Octavianto, Andrew; Guntur Aritonang, Edison; Nova Imaduddin, Malya; Dedi; Rilaningrum, Magfira

    2017-10-01

    The development of human's population is having effect on the increase of facilities and transportation needs. One of the primary problems is the availability of parking area. This has occurred in Universitas Indonesia (UI), mainly in Salemba Campus. The availability of land is not as equal as the number of vehicles, which are to be parked, that is why the convenience of students, lecturers and employees at UI is unsatisfactory. The purpose of this paper is to know the level of parking convenience that is affected by the capacity of parking lots and the volume of vehicles in UI Salemba Campus. The results of this research indicate Salemba campus's parking index. The motor index is still in the category of medium (index 0.945) and the car parking index has less category with a parking index 0.485. While with the location of research object being behind the UI Salemba campus, the results obtained were both the motor and the car are still in the category of “enough” with the parking index of, that is 0.657 for the motor and 0.777 for the car. So theoretically, the parking management at Salemba Campus is in an unsustainable parking degree because, if there is no long-term solution, it will increase congestion in the surrounding area and intensify the dissatisfaction of existing parking users.

  4. Distribution of cold-water corals in the Whittard Canyon, NE Atlantic Ocean

    OpenAIRE

    Morris, Kirsty J.; Tyler, Paul A.; Masson, Doug G.; Huvenne, Veerle A.I.; Rogers, Alex D.

    2013-01-01

    The deep-sea floor occupies about 60% of the surface of the planet and is covered mainly by fine sediments. Most studies of deep-sea benthic fauna therefore have concentrated on soft sediments with little sampling of hard substrata, such as rocky outcrops in submarine canyons. Here we assess the distribution and abundance of cold-water corals within the Whittard Canyon (NE Atlantic) using video footage from the ROV Isis. Abundances per 100 m of video transect were calculated and mapped using ...

  5. Habitat Mapping Cruise - Hudson Canyon (HB0904, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Objectives are to: 1) perform multibeam mapping of transitional and deepwater habitats in Hudson Canyon (off New Jersey) with the National Institute of Undersea...

  6. IMPORTANT INFORMATION - Flagstaff Car-Park and Park-and-Ride (P+R)

    CERN Document Server

    GS Department

    2011-01-01

    As part of the new arrangements following the arrival of the tram-line at CERN, an Automatic Number-Plate Recognition (ANPR) system has been installed restricting access to the Flagstaff Car-park and the Park-and-Ride (P+R) zone according to the conditions set out below: Holders of a valid P+R user card may enter the car-park at all hours but may only park in the area specifically designated as the P+R zone. P+R user cards can be purchased from the Fondation des Parkings de Genève (http://www.ge.ch/parkings/abonnements.html)   Members of CERN personnel and of contractors' personnel, whatever their status, may freely access the Flagstaff Car-Park at all hours, as long as their vehicle is duly registered with CERN, but they may not use the P+R zone, which is reserved for holders of P+R user cards. Please check that your vehicle number-plates are properly registered via AdaMS (http://cern.ch/adams). If this is not the case, the following action must be taken: - for private or co...

  7. Columbus State University Global Observation and Outreach for the 2012 Transit of Venus

    Science.gov (United States)

    Perry, Matthew; McCarty, C.; Bartow, M.; Hood, J. C.; Lodder, K.; Johnson, M.; Cruzen, S. T.; Williams, R. N.

    2013-01-01

    Faculty, staff and students from Columbus State University’s (CSU’s) Coca-Cola Space Science Center presented a webcast of the 2012 Transit of Venus from three continents to a global audience of 1.4 million unique viewers. Team members imaged the transit with telescopes using white-light, hydrogen-alpha, and calcium filters, from Alice Springs, Australia; the Gobi Desert, Mongolia; Bryce Canyon, UT; and Columbus, GA. Images were webcast live during the transit in partnership with NASA’s Sun-Earth Day program, and Science Center staff members were featured on NASA TV. Local members of the public were brought in for a series of outreach initiatives, in both Georgia and Australia, before and during the transit. The data recorded from the various locations have been archived for use in demonstrating principles such as the historical measurement of the astronomical unit.

  8. Canyon Creek: A late Pleistocene vertebrate locality in interior Alaska

    Science.gov (United States)

    Weber, Florence R.; Hamilton, Thomas D.; Hopkins, David M.; Repenning, Charles A.; Haas, Herbert

    1981-09-01

    The Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene. Tanana River gravel at the base of the section evidently formed during the Delta Glaciation of the north-central Alaska Range. Younger layers and lenses of fluvial sand are interbedded with arkosic gravel from Canyon Creek that contains tephra as well as fossil bones of an interstadial fauna about 40,000 years old. Solifluction deposits containing ventifacts, wedge casts, and rodent burrows formed during a subsequent period of periglacial activity that took place during the maximum phase of Donnelly Glaciation about 25,000-17,000 years ago. Overlying sheets of eolian sand are separated by a 9500-year-old paleosol that may correlate with a phase of early Holocene spruce expansion through central Alaska. The Pleistocene fauna from Canyon Creek consists of rodents (indicated by burrows), Mammuthus primigenius (woolly mammoth), Equus lambei (Yukon wild ass), Camelops hesternus (western camel), Bison sp. cf. B. crassicornis (large-horned bison), Ovis sp. cf. O. dalli (mountain sheep), Canis sp. cf. C. lupus (wolf), Lepus sp. cf. L. othus or L. arcticus (tundra hare), and Rangifer sp. (caribou). This assemblage suggests an open landscape in which trees and tall shrubs were either absent or confined to sheltered and moist sites. Camelops evidently was present in eastern Beringia during the middle Wisconsin interstadial interval but may have disappeared during the following glacial episode. The stratigraphic section at Canyon Creek appears to demonstrate that the Delta Glaciation of the north-central Alaska Range is at least in part of early Wisconsin age and was separated from the succeeding Donnelly Glaciation by an interstadial rather than interglacial episode.

  9. Perceived Health Benefits and Willingness to Pay for Parks by Park Users: Quantitative and Qualitative Research

    Directory of Open Access Journals (Sweden)

    Claire Henderson-Wilson

    2017-05-01

    Full Text Available Whilst a growing body of evidence demonstrates people derive a range of health and wellbeing benefits from visiting parks, only a limited number of attempts have been made to provide a complementary economic assessment of parks. The aim of this exploratory study was to directly estimate the perceived health and wellbeing benefits attained from parks and the economic value assigned to parks by park users in Victoria, Australia. The research employed a mixed methods approach (survey and interviews to collect primary data from a selection of 140 park users: 100 from two metropolitan parks in Melbourne and 40 from a park on the urban fringe of Melbourne, Victoria. Our findings suggest that park users derive a range of perceived physical, mental/spiritual, and social health benefits, but park use was predominantly associated with physical health benefits. Overall, our exploratory study findings suggest that park users are willing to pay for parks, as they highly value them as places for exercising, socialising, and relaxing. Importantly, most people would miss parks if they did not exist. The findings aim to provide park managers, public health advocates, and urban policy makers with evidence about the perceived health and wellbeing benefits of park usage and the economic value park visitors place on parks.

  10. Heavy mineral sorting in downwards injected Palaeocene sandstone, Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov

    2011-01-01

    Post-depositional remobilization and injection of sand are often seen in deep-water clastic systems and has been recently recognised as a significant modifier of deep-water sandstone geometry. Large-scale injectite complexes have been interpreted from borehole data in the Palaeocene Siri Canyon...... of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilised sandstones is often ambiguous. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units in the Siri Canyon and has been interpreted to represent the depositional...... sorting. In this study we describe an example of effective shear-zone sorting of heavy minerals in a thin downward injected sandstone dyke which was encountered in one of the cores in the Cecilie Field, Siri Canyon. Differences in sorting pattern of heavy minerals are suggested as a tool for petrographic...

  11. Capability to Recover Plutonium-238 in H-Canyon/HB-Line - 13248

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Kenneth S. Jr.; Smith, Robert H. Jr.; Goergen, Charles R. [Savannah River Nuclear Solutions, LLC, Savannah River Site, Aiken, SC 29802 (United States)

    2013-07-01

    Plutonium-238 is used in Radioisotope Thermoelectric Generators (RTGs) to generate electrical power and in Radioisotope Heater Units (RHUs) to produce heat for electronics and environmental control for deep space missions. The domestic supply of Pu-238 consists of scrap material from previous mission production or material purchased from Russia. Currently, the United States has no significant production scale operational capability to produce and separate new Pu-238 from irradiated neptunium-237 targets. The Department of Energy - Nuclear Energy is currently evaluating and developing plans to reconstitute the United States capability to produce Pu-238 from irradiated Np-237 targets. The Savannah River Site had previously produced and/or processed all the Pu-238 utilized in Radioisotope Thermoelectric Generators (RTGs) for deep space missions up to and including the majority of the plutonium for the Cassini Mission. The previous full production cycle capabilities included: Np- 237 target fabrication, target irradiation, target dissolution and Np-237 and Pu-238 separation and purification, conversion of Np-237 and Pu-238 to oxide, scrap recovery, and Pu-238 encapsulation. The capability and equipment still exist and could be revitalized or put back into service to recover and purify Pu-238/Np-237 or broken General Purpose Heat Source (GPHS) pellets utilizing existing process equipment in HB-Line Scrap Recovery, and H-Canyon Frame Waste Recovery processes. The conversion of Np-237 and Pu-238 to oxide can be performed in the existing HB-Line Phase-2 and Phase- 3 Processes. Dissolution of irradiated Np-237 target material, and separation and purification of Np-237 and Pu-238 product streams would be possible at production rates of ∼2 kg/month of Pu-238 if the existing H-Canyon Frames Process spare equipment were re-installed. Previously, the primary H-Canyon Frames equipment was removed to be replaced: however, the replacement project was stopped. The spare equipment

  12. Are TODs Over-Parked?

    OpenAIRE

    Cervero, Robert; Adkins, Arlie; Sullivan, Cathleen

    2009-01-01

    This study empirically investigates the proposition that TOD, and specifically housing near suburban rail stops, is “over-parked†in the U.S. This is done by comparing parking generation rates for 31 housing complexes near rail stops in the San Francisco Bay Area and Portland, Oregon with on-site parking supplies and with ITE parking generation rates. Factors that explain parking demand for transit-oriented housing are also investigated, both statistically and through case analyses. The re...

  13. Archaeological Test and Data Recovery Program at Telegraph Canyon, Chula Vista, California,

    Science.gov (United States)

    1978-09-01

    Several areas in the immediate vicinity were known to contain subsurface cables used to control SDG &E’s power network, and required avoidance. Addi...3 oEST FACE A TRENCH 4 Corps of Engineers Telegraph Canyon Creek WESTEC Servjces. Inr . compass bearing 20 7 ;7777,77 .77 7 1 METERS 170 c{ METERS...666 1.00 ~ 0 1.33 E -2.*00 -2.33 2.66 3.00 FUREf TRENCH 4 Corps of EngineersgTelegraph Canyon Creek; compass bearing 20 28 ’Lb..--._ .. *.* o •- -. o

  14. Spatial distribution assessment of particulate matter in an urban street canyon using biomagnetic leaf monitoring of tree crown deposited particles

    International Nuclear Information System (INIS)

    Hofman, Jelle; Stokkaer, Ines; Snauwaert, Lies; Samson, Roeland

    2013-01-01

    Recently, biomagnetic monitoring of tree leaves has proven to be a good estimator for ambient particulate concentration. This paper investigates the usefulness of biomagnetic leaf monitoring of crown deposited particles to assess the spatial PM distribution inside individual tree crowns and an urban street canyon in Ghent (Belgium). Results demonstrate that biomagnetic monitoring can be used to assess spatial PM variations, even within single tree crowns. SIRM values decrease exponentially with height and azimuthal effects are obtained for wind exposed sides of the street canyon. Edge and canyon trees seem to be exposed differently. As far as we know, this study is the first to present biomagnetic monitoring results of different trees within a single street canyon. The results not only give valuable insights into the spatial distribution of particulate matter inside tree crowns and a street canyon, but also offer a great potential as validation tool for air quality modelling. Highlights: ► Spatial distribution of tree crown deposited PM was evaluated. ► SIRM values decrease exponentially with height. ► Azimuthal effects were observed at wind exposed sides of the street canyon. ► Edge and canyon trees seem to be exposed differently. ► Biomagnetic monitoring offers a great potential as validation of air quality models. -- Biomagnetic leaf monitoring provides useful insights into the spatial distribution of particulates inside individual tree crowns and an urban street canyon in Ghent (Belgium)

  15. A new model for turbidity current behavior based on integration of flow monitoring and precision coring in a submarine canyon

    Science.gov (United States)

    Symons, William O.; Sumner, Esther J.; Paull, Charles K.; Cartigny, Matthieu J.B.; Xu, Jingping; Maier, Katherine L.; Lorenson, Thomas; Talling, Peter J.

    2017-01-01

    Submarine turbidity currents create some of the largest sediment accumulations on Earth, yet there are few direct measurements of these flows. Instead, most of our understanding of turbidity currents results from analyzing their deposits in the sedimentary record. However, the lack of direct flow measurements means that there is considerable debate regarding how to interpret flow properties from ancient deposits. This novel study combines detailed flow monitoring with unusually precisely located cores at different heights, and multiple locations, within the Monterey submarine canyon, offshore California, USA. Dating demonstrates that the cores include the time interval that flows were monitored in the canyon, albeit individual layers cannot be tied to specific flows. There is good correlation between grain sizes collected by traps within the flow and grain sizes measured in cores from similar heights on the canyon walls. Synthesis of flow and deposit data suggests that turbidity currents sourced from the upper reaches of Monterey Canyon comprise three flow phases. Initially, a thin (38–50 m) powerful flow in the upper canyon can transport, tilt, and break the most proximal moorings and deposit chaotic sands and gravel on the canyon floor. The initially thin flow front then thickens and deposits interbedded sands and silty muds on the canyon walls as much as 62 m above the canyon floor. Finally, the flow thickens along its length, thus lofting silty mud and depositing it at greater altitudes than the previous deposits and in excess of 70 m altitude.

  16. Bark in the Park: A Review of Domestic Dogs in Parks

    Science.gov (United States)

    Weston, Michael A.; Fitzsimons, James A.; Wescott, Geoffrey; Miller, Kelly K.; Ekanayake, Kasun B.; Schneider, Thomas

    2014-09-01

    The presence of domestic dogs Canis familiaris in public open spaces is increasingly controversial. In our review of the literature, we located 133 publications of various types (papers, reports etc.) that examine some aspect of dogs in parks and open spaces (50 % focussed solely on dogs). There has been an exponential growth in the cumulative number of articles ( R 2 = 0.96; 82 % published since 1997); almost all pertain to temperate latitudes (97 %) and most to the northern hemisphere (62 %). Most articles focus on impacts on wildlife (51 %), zoonotic diseases (17 %), and people's perceptions regarding dogs (12 %). Articles mostly describe problems associated with dogs, while reports of low compliance with dog regulations are common. We outline six major findings regarding dogs in parks: (1) there is a paucity of information on dogs in parks, particularly in relation to their interactions with wildlife and regarding their management; (2) published studies are mainly restricted to a handful of locations in developed countries; (3) sectors of societies hold different views over the desirability of dogs in parks; (4) the benefits and risks of dogs to humans and park values are poorly documented and known; (5) dogs represent a notable disease risk in some but not all countries; and (6) coastal parks are over-represented in the literature in terms of potential negative impacts. Park managers globally require better information to achieve conservation outcomes from dog management in parks.

  17. Direct Measurements of the Evolution and Impact of Sediment Density Flows as they Pass Through Monterey Submarine Canyon, Offshore California

    Science.gov (United States)

    Paull, C. K.; Talling, P.; Maier, K. L.; Parsons, D. R.; Xu, J.; Caress, D. W.; Gwiazda, R.; Lundsten, E. M.; Anderson, K.; Barry, J.; Chaffey, M. R.; O'Reilly, T. C.; Rosenberger, K. J.; Gales, J. A.; McGann, M.; McCann, M. P.; Simmons, S.; Sumner, E.

    2017-12-01

    Sediment density flows flushing through submarine canyons carry globally significant amounts of material into the deep sea to form many of the largest sediment accumulations on Earth. Despite their global significance, these flows remain poorly understood because they have rarely been directly measured. Here we provide an initial overview of the recently completed Coordinated Canyon Experiment (CCE), which was undertaken specifically to provide detailed measurements of sediment density flows and their impact on seafloor morphology and sedimentology. No previous study has deployed as extensive an array of monitoring sensors along a turbidity current pathway. During the 18 months of the CCE, at least 15 sediment density flows were recorded within the axis of Monterey Canyon. Because no external triggers (i.e., earthquakes or floods) correlate with these flows, they must have originated as failures in the canyon floor or canyon flanks. Three flows ignited and ran out for > 50 km from water depths of 1,860 m, reaching velocities up to 8.1 m/s. The rest of the flows died out within the array. During these events, large objects on or in the canyon floor were displaced substantial distances downslope, including a 7.1 km downslope movement of an entire mooring; a 4.6 km displacement of an 860 kg instrument frame followed by repeated down canyon displacements of this same frame after it was entombed in sediment; and multiple depth changes of man-made boulders containing acceleration and pressure sensors. During this same time interval the canyon floor was mapped six times with autonomous underwater vehicles covering the canyon thalweg at the upper and lower end of the instrument array (200-540 and 1350-1880 m water depths). The repeated mapping surveys reveal that flows caused +3 to -3 m bathymetric changes within a continuous clearly defined 200 m wide swath running along the canyon axis in 540 m water depth. This study shows that sediment density flows caused massive

  18. Sediment transport processes at the head of Halibut Canyon, Eastern Canada margin: An interplay between internal tides and dense shelf water cascading.

    Science.gov (United States)

    Puig, Pere; Greenan, Blair J. W.; Li, Michael Z.; Prescott, Robert H.; Piper, David J. W.

    2013-04-01

    To investigate the processes by which sediment is transported through a submarine canyon incised in a glaciated margin, the bottom boundary layer quadrapod RALPH was deployed at 276-m depth in the West Halibut Canyon (off Newfoundland) during winter 2008-2009. Two main sediment transport processes were identified throughout the deployment. Firstly, periodic increases of near-bottom suspended-sediment concentrations (SSC) were recorded associated with the up-canyon propagation of the semidiurnal internal tidal bore along the canyon axis, carrying fine sediment particles resuspended from deeper canyon regions. The recorded SSC peaks, lasting less than one hour, were observed sporadically and were linked to bottom intensified up-canyon flows concomitant with sharp drops in temperature. Secondly, sediment transport was also observed during events of intensified down-canyon current velocities that occurred during periods of sustained heat loss from surface waters, but were not associated with large storms. High-resolution velocity profiles throughout the water column during these events revealed that the highest current speeds (~1 m s-1) were centered several meters above the sea floor and corresponded to the region of maximum velocities of a gravity flow. Such flows had associated low SSC and cold water temperatures and have been interpreted as dense shelf water cascading events channelized along the canyon axis. Sediment transport during these events was largely restricted to bedload and saltation, producing winnowing of sands and fine sediments around larger gravel particles. Analysis of historical hydrographic data suggests that the origin of such gravity flows is not related to the formation of coastal dense waters advected towards the canyon head. Rather, the dense shelf waters appear to be generated around the outer shelf, where convection during winter is able to reach the sea floor and generate a pool of near-bottom dense water that cascades into the canyon

  19. Multibeam bathymetric survey of the Ipala Submarine Canyon, Jalisco, Mexico (20°N): The southern boundary of the Banderas Forearc Block?

    Science.gov (United States)

    Urías Espinosa, J.; Bandy, W. L.; Mortera Gutiérrez, C. A.; Núñez Cornú, Fco. J.; Mitchell, N. C.

    2016-03-01

    The Middle America Trench bends sharply northward at 20°N. This, along with the close proximity of the Rivera-North America Euler pole to the northern end of this trench, sharply increases the obliquity of subduction at 20°N. By analogy with other subduction zones with similar sharply changing obliquity, significant trench parallel extension is expected to exist in the forearc region near the bend. To evaluate this possibility, multibeam bathymetric, seafloor backscatter and sub-bottom seismic reflection data were collected in this area during the MORTIC08 campaign of the B.O. El Puma. These data image in detail a large submarine canyon (the Ipala Canyon) extending from the coast at 20°05‧N to the Middle America Trench at 19°50‧N. This canyon is 114 km long and is fed by sediments originating from two, possibly three, small rivers: the Ipala, Tecolotlán and Maria Garza. This canyon deeply incises (up to 600 m) the entire continental slope and at least the outer part of the shelf. Within the canyon, we observe meanders and narrow channels produced by turbidity flows indicating that the canyon is active. In the marginal areas of the canyon slumps, rills, and uplifts suggest that mass movements and fluid flow have had a major impact on the seafloor morphology. The seafloor bathymetry, backscatter images and sub-bottom reflection profiles evidence the tectonic processes occurring in this area. Of particular interest, the canyon is deflected by almost 90° at three locations, the deflections all having a similar azimuth of between 125° and 130°. Given the prominence and geometry of this canyon, along with its tectonic setting, we propose that the presence of the canyon is related to extension produced by the sharp change in the plate convergence. If so, the canyon may lie along the southeast boundary of a major forearc block (the Banderas Forearc Block).

  20. Consumption and cost of diesel oil on cultivation of Zoysiagrass (Zoysia japonica Steud.) irrigated by aspersion canyons under two irrigation handlings

    Energy Technology Data Exchange (ETDEWEB)

    Mazaroni, Bruno Henrique Silveira; Turco, Jose Eduardo Pitelli; Coan, Ruchele Marchiori; Gerolineto, Eduardo [Universidade Estadual Paulista (FCAV/UNESP), Jaboticabal, SP (Brazil). Fac. de Ciencias Agrarias e Veterinarias

    2008-07-01

    This work aim to analyse the consumption and cost of diesel oil on cultivation of zoysiagrass (Zoysia japonica Steud.) irrigated by aspersion canyon, submitted of to two irrigation handling: T1 - irrigated when the tensiometer reading is equal - 0,5 atmospheres and T2 - irrigated by grass growers methodology. The research was carried on Green-Park Farm, in the city of Pitangueiras, SP. Consumption of diesel oil was measured from a diesel engine, brand MWM, turbined with 6 cylinders, type D-229 for zoysiagrass production. The diesel price was gotten from Petroleum National Agency (ANP), being an average price in Sao Paulo State, in February 2007, converted into the commercial dollar. Economical result was studied, subtracting the selling value of the grass, by the cost of the fuel consumed, for both T1 and T2 treatments. The treatment made by tensiometer showed greater diesel consumption, related to treatment T2, where the handling was made by the grass grower. (author)

  1. Conditions for the management of carrying capacity in the parks of Parks&Benefits

    DEFF Research Database (Denmark)

    Brandt, Jesper; Holmes, Esbern

    2011-01-01

    Growth in the number of visitors is an upcoming problem in nature parks. Nature parks are at the same time facing increasing demand, falling public appropriations and receding focus on their conservation functions. To ensure a balancing of nature protection and economic utilization the concept...... stakeholders, balancing use and protection preferably based on scientific and/or experiential cognition. The conditions for the management of carrying capacity for the 8 nature parks in the EC Baltic Project Parks&Benefits are analysed in the report. 1. Part focus on the methodology, concentrated...... on the comparison of the common conditions related to the international nature protection obligations in the parks, primarily expressed through the management under the EU Natura2000-program. In part 2, a comparison of the 8 parks concerning extent, land use composition, population in and around the park...

  2. 75 FR 18201 - Juniper Canyon Wind Power, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

    Science.gov (United States)

    2010-04-09

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER10-975-000] Juniper Canyon Wind Power, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket... of Juniper Canyon Wind Power, LLC's application for market-based rate authority, with an accompanying...

  3. New York Canyon Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Raemy, Bernard

    2012-06-21

    The New York Canyon Stimulation Project was to demonstrate the commercial application of Enhanced Geothermal System techniques in Buena Vista Valley area of Pershing County, Nevada. From October 2009 to early 2012, TGP Development Company aggressively implemented Phase I of Pre-Stimulation and Site/Wellbore readiness. This included: geological studies; water studies and analyses and procurement of initial permits for drilling. Oversubscription of water rights and lack of water needed for implementation of EGS were identified and remained primary obstacles. Despite extended efforts to find alternative solutions, the water supply circumstances could not be overcome and led TGP to determine a "No Go" decision and initiate project termination in April 2012.

  4. Large eddy simulation of reactive pollutants in a deep urban street canyon: Coupling dynamics with O3-NOx-VOC chemistry.

    Science.gov (United States)

    Zhong, Jian; Cai, Xiao-Ming; Bloss, William James

    2017-05-01

    A large eddy simulation (LES) model coupled with O 3 -NO x -VOC chemistry is implemented to simulate the coupled effects of emissions, mixing and chemical pre-processing within an idealised deep (aspect ratio = 2) urban street canyon under a weak wind condition. Reactive pollutants exhibit significant spatial variations in the presence of two vertically aligned unsteady vortices formed in the canyon. Comparison of the LES results from two chemical schemes (simple NO x -O 3 chemistry and a more comprehensive Reduced Chemical Scheme (RCS) chemical mechanism) shows that the concentrations of NO 2 and O x inside the street canyon are enhanced by approximately 30-40% via OH/HO 2 chemistry. NO, NO x , O 3 , OH and HO 2 are chemically consumed, while NO 2 and O x (total oxidant) are chemically produced within the canyon environment. Within-canyon pre-processing increases oxidant fluxes from the canyon to the overlying boundary layer, and this effect is greater for deeper street canyons (as found in many traditional European urban centres) than shallower (lower aspect ratio) streets. There is clear evidence of distinct behaviours for emitted chemical species and entrained chemical species, and positive (or negative) values of intensities of segregations are found between pairs of species with similar (or opposite) behaviour. The simplified two-box model underestimated NO and O 3 levels, but overestimated NO 2 levels for both the lower and upper canyon compared with the more realistic LES-chemistry model. This suggests that the segregation effect due to incomplete mixing reduces the chemical conversion rate of NO to NO 2 . This study reveals the impacts of nonlinear O 3 -NO x -VOC photochemical processes in the incomplete mixing environment and provides a better understanding of the pre-processing of emissions within canyons, prior to their release to the urban boundary layer, through the coupling of street canyon dynamics and chemistry. Copyright © 2017 Elsevier Ltd

  5. Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland.

    Science.gov (United States)

    Baynes, Edwin R C; Attal, Mikaël; Niedermann, Samuel; Kirstein, Linda A; Dugmore, Andrew J; Naylor, Mark

    2015-02-24

    Extreme flood events have the potential to cause catastrophic landscape change in short periods of time (10(0) to 10(3) h). However, their impacts are rarely considered in studies of long-term landscape evolution (>10(3) y), because the mechanisms of erosion during such floods are poorly constrained. Here we use topographic analysis and cosmogenic (3)He surface exposure dating of fluvially sculpted surfaces to determine the impact of extreme flood events within the Jökulsárgljúfur canyon (northeast Iceland) and to constrain the mechanisms of bedrock erosion during these events. Surface exposure ages allow identification of three periods of intense canyon cutting about 9 ka ago, 5 ka ago, and 2 ka ago during which multiple large knickpoints retreated large distances (>2 km). During these events, a threshold flow depth was exceeded, leading to the toppling and transportation of basalt lava columns. Despite continuing and comparatively large-scale (500 m(3)/s) discharge of sediment-rich glacial meltwater, there is no evidence for a transition to an abrasion-dominated erosion regime since the last erosive event because the vertical knickpoints have not diffused over time. We provide a model for the evolution of the Jökulsárgljúfur canyon through the reconstruction of the river profile and canyon morphology at different stages over the last 9 ka and highlight the dominant role played by extreme flood events in the shaping of this landscape during the Holocene.

  6. Hudson Canyon benthic habitats characterization and mapping by integrated analysis of multidisciplinary data

    Science.gov (United States)

    Pierdomenico, Martina; Guida, Vincent G.; Rona, Peter A.; Macelloni, Leonardo; Scranton, Mary I.; Asper, Vernon; Diercks, Arne

    2013-04-01

    Hudson Canyon, about 180 km SE of New York City, is the largest eastern U.S. submarine canyon and is under consideration for HAPC (Habitat Area of Particular Concern) status, representing a fisheries and biodiversity hot spot. Interest in the area, within the perspective of ecosystem based management, marine spatial planning, habitat and species conservation, led to a joint project between NOAA Northeast Fisheries, U.S. Geological Survey (USGS), Mississippi Mineral Research Institute (MMRI), National Institute for Undersea Science and Technology (NIUST), Stony Brook and Rutgers Universities for the study of benthic habitats, that includes the assembly of existing data with newly collected ones: acoustic mapping, visual ground-truthing, hydrographic, sedimentological, and trawl data collections. Acoustic mapping, performed using AUV-mounted multibeam sonar, provided ultra-high resolution bathymetric and backscatter imagery (3m and 1m respectively) at all water depths for identification of geomorphological features and for the characterization of surficial sediments along the two thirds of the shelf portion of the canyon. Identification of benthic and demersal communities was accomplished by visual ground thruthing with underwater vehicle video and still cameras, and from trawl catch data. A CTD-rosette sampler provided water column salinity-temperature profiles and water samples for dissolved methane analysis in the vicinity of suspected bottom sources. Analysis of data revealed a complex of topographic structures and hydrological patterns that provide a wide range of physical habitats in a relatively small area. A mosaic of sandy and muddy substrates, gravel beds, rock outcrops, and semilithified clay outcrops host rich and varied faunal assemblages, including deepwater corals and sponge communities. Pockmark fields, occurring below 300 m depth, suggest that methane-based chemosynthetic carbonate deposition contributes to creation of specific hard bottom habitats

  7. Study on the wind field and pollutant dispersion in street canyons using a stable numerical method.

    Science.gov (United States)

    Xia, Ji-Yang; Leung, Dennis Y C

    2005-01-01

    A stable finite element method for the time dependent Navier-Stokes equations was used for studying the wind flow and pollutant dispersion within street canyons. A three-step fractional method was used to solve the velocity field and the pressure field separately from the governing equations. The Streamline Upwind Petrov-Galerkin (SUPG) method was used to get stable numerical results. Numerical oscillation was minimized and satisfactory results can be obtained for flows at high Reynolds numbers. Simulating the flow over a square cylinder within a wide range of Reynolds numbers validates the wind field model. The Strouhal numbers obtained from the numerical simulation had a good agreement with those obtained from experiment. The wind field model developed in the present study is applied to simulate more complex flow phenomena in street canyons with two different building configurations. The results indicated that the flow at rooftop of buildings might not be assumed parallel to the ground as some numerical modelers did. A counter-clockwise rotating vortex may be found in street canyons with an inflow from the left to right. In addition, increasing building height can increase velocity fluctuations in the street canyon under certain circumstances, which facilitate pollutant dispersion. At high Reynolds numbers, the flow regimes in street canyons do not change with inflow velocity.

  8. Exploration of Science Parks

    Institute of Scientific and Technical Information of China (English)

    Xiong Huibing; Sun Nengli

    2005-01-01

    Science parks have developed gready in the world, whereas empirical researches have showed that science parks based on linear model cannot guarantee the creation of innovation. Hi-tech innovation is derived from flow and management of information. The commercial and social interactions between in-parks and off-park firms and research institutions act as the key determinant for innovation.Industrial clustering is the rational choice for further developing Chinese science parks and solving some problems such as the lack of dear major industries and strong innovation sense, etc.

  9. Pollutant Removal, Dispersion and Entrainment over Two-Dimensional Idealized Street Canyons: an LES Approach

    Science.gov (United States)

    Wong, C.; Liu, C.

    2010-12-01

    Unlike pollutant transport over flat terrain, the mechanism and plume dispersion over urban areas is not well known. This study is therefore conceived to examine how urban morphology modifies the pollutant transport over urban areas. The computational domain and boundary condition used in this study is shown in Figure 1. The LES shows that inside the street canyon, the ground-level pollutants are carried to roof-level by the re-circulating flow, which are then removed from the street canyon to the UBL. Right above the roof level, narrow high-speed air masses in the streamwise flows and intensive downdrafts have been found in the shear layer. Different from the flows over a smooth surface, the maximum turbulence intensities descend that are peaked near the top of the building roughness. The pollutant is rather uniformly distributed inside a street canyon but disperses rapidly over the buildings exhibiting a Gaussian-plume form in the UBL. The mean component of vertical pollutant flux shows that the mean wind contributes to pollutant removal and entrainment simultaneously. Whereas, the fluctuating component demystifies that pollutant removal is mainly governed by atmospheric turbulence. Over the roof level, atmospheric flows slow down rapidly in the wake behind leeward building, suggesting the momentum entrainment into the street canyons. The decelerating streamwise flows in turn lead to upward flows carrying pollutants away from the street canyons, illustrating the basic pollutant removal mechanism in the skimming flow regime. Figure 1: Computational domain and boundary conditions Figure 2: Ensemble average vertical pollutant flux along the roof level. (a). Mean component; (b). turbulent component.

  10. Coupling dynamics and chemistry in the air pollution modelling of street canyons: A review.

    Science.gov (United States)

    Zhong, Jian; Cai, Xiao-Ming; Bloss, William James

    2016-07-01

    Air pollutants emitted from vehicles in street canyons may be reactive, undergoing mixing and chemical processing before escaping into the overlying atmosphere. The deterioration of air quality in street canyons occurs due to combined effects of proximate emission sources, dynamical processes (reduced dispersion) and chemical processes (evolution of reactive primary and formation of secondary pollutants). The coupling between dynamics and chemistry plays a major role in determining street canyon air quality, and numerical model approaches to represent this coupling are reviewed in this article. Dynamical processes can be represented by Computational Fluid Dynamics (CFD) techniques. The choice of CFD approach (mainly the Reynolds-Averaged Navier-Stokes (RANS) and Large-Eddy Simulation (LES) models) depends on the computational cost, the accuracy required and hence the application. Simplified parameterisations of the overall integrated effect of dynamics in street canyons provide capability to handle relatively complex chemistry in practical applications. Chemical processes are represented by a chemical mechanism, which describes mathematically the chemical removal and formation of primary and secondary species. Coupling between these aspects needs to accommodate transport, dispersion and chemical reactions for reactive pollutants, especially fast chemical reactions with time scales comparable to or shorter than those of typical turbulent eddies inside the street canyon. Different approaches to dynamical and chemical coupling have varying strengths, costs and levels of accuracy, which must be considered in their use for provision of reference information concerning urban canopy air pollution to stakeholders considering traffic and urban planning policies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 11a: giant sequoias

    Science.gov (United States)

    York, Robert A.; Stephenson, Nathan L.; Meyer, Marc; Hanna, Steve; Tadashi, Moody; Caprio, Anthony C.; Battles, John J.

    2013-01-01

    For natural resource managers in the southern Sierra Nevada, giant sequoia requires very little introduction. It receives great attention as an icon of western forests and as a common namesake with the areas where it occurs. While it is a single component of a very complex system, its attention in this assessment and in general is well deserved. Giant sequoia is one of the few "destination species" that attracts a wide swath of the public by nature of it simply being present. It draws people, who otherwise may not travel, to a natural environment. The result is an expansion of the public’s sense of natural resource stewardship. Because park managers could not achieve their mission without public support, this fostering role of giant sequoia is critical for park natural resources and is important for natural resources in general. Despite its social relevance and physical size, we re-emphasize here that the giant sequoia resource is a relatively small component of the ecosystems of the southern Sierra Nevada. As is the case with all of the resources assessed in the NRCA, we focus on giant sequoia with the understanding that other resources will be considered simultaneously when evaluating management decisions that impact giant sequoia. While we attempt to explicitly address the interaction of giant sequoia with other resources and stressors, we also realize that ultimately managers will integrate much more information than is presented here when making decisions that influence giant sequoia. The autecology and management issues surrounding giant sequoia have been thoroughly reviewed elsewhere (Harvey et al. 1980, Aune 1994, Stephenson 1996). Stephenson (1996), in particular, should be reviewed when considering any management decisions that potentially impact giant sequoia. For those who may not be familiar with giant sequoia ecology, a summary of basic information is provided in a table below. In some parts of this assessment, we reproduce text from Stephenson

  12. A multi-approach monitoring of particulate matter, metals and PAHs in an urban street canyon.

    Science.gov (United States)

    De Nicola, Flavia; Murena, Fabio; Costagliola, M Antonietta; Alfani, Anna; Baldantoni, Daniela; Prati, M Vittoria; Sessa, Ludovica; Spagnuolo, Valeria; Giordano, Simonetta

    2013-07-01

    For the first time until now, the results from a prediction model (Atmospheric Dispersion Modelling System (ADMS)-Road) of pollutant dispersion in a street canyon were compared to the results obtained from biomonitors. In particular, the instrumental monitoring of particulate matter (PM10) and the biomonitoring of 14 polycyclic aromatic hydrocarbons (PAHs) and 11 metals by Quercus ilex leaves and Hypnum cupressiforme moss bags, acting as long- and short-term accumulators, respectively, were carried out. For both PAHs and metals, similar bioaccumulation trends were observed, with higher concentrations in biomonitors exposed at the leeward canyon side, affected by primary air vortex. The major pollutant accumulation at the leeward side was also predicted by the ADMS-Road model, on the basis of the prevailing wind direction that determines different exposure of the street canyon sides to pollutants emitted by vehicular traffic. A clear vertical (3, 6 and 9 m) distribution gradient of pollutants was not observed, so that both the model and biomonitoring results suggested that local air turbulences in the street canyon could contribute to uniform pollutant distribution at different heights.

  13. Parking management : strategies, evaluation and planning

    International Nuclear Information System (INIS)

    Litman, T.A.

    2006-01-01

    Parking facilities are a major cost to society. Current planning practices are based on the assumption that parking should be abundant and provided free, with costs borne indirectly. This report examined parking management strategies related to integrated parking plans. Problems with current parking planning practices were reviewed. The costs of parking facilities were examined, as well as the savings that can accrue from improved management techniques. Strategies included shared parking; remote parking and shuttle services; walking and cycling improvements; improved enforcement and control; and increasing the capacity of existing parking facilities. Parking pricing methods, financial incentives and parking tax reforms were reviewed. Issues concerning user information and marketing were examined. Overflow parking plans were evaluated. Three illustrative examples of parking management programs were outlined, along with details of implementation, planning and evaluation procedures. It was concluded that cost-effective parking management programs can often reduce parking requirements by 20 to 40 per cent compared with conventional planning requirements, in addition to providing economic, social and environmental benefits. 32 refs., 7 tabs., 3 figs

  14. Sedimentation in Rio La Venta Canyon in Netzahualcoyotl Reservoir, Chiapas, Mexico

    Science.gov (United States)

    de La Fuente, J. A.; Lisle, T.; Velasquez, J.; Allison, B. L.; Miller, A.

    2002-12-01

    Sedimentation of Rio La Venta as it enters the Netzahualcoyotl Reservoir in Chiapas, Mexico, threatens a unique part of the aquatic ecosystem. Rio La Venta enters the reservoir via a narrow canyon about 16 km long with spectacular, near-vertical limestone bluffs up to 320 m high and inhabited by the flora and fauna of a pristine tropical forest. Karst terrain underlies most of the Rio La Venta basin in the vicinity of the reservoir, while deeply weathered granitic terrain underlies the Rio Negro basin, and the headwaters of the Rio La Venta to the south. The Rio Negro joins Rio La Venta 3 km downstream of the upper limit of the reservoir and delivers the bulk of the total clastic sediment (mostly sand and finer material). The canyon and much of the contributing basin lie within the Reserva de la Biosfera, Selva El Ocote, administered by the Comision Nacional de Areas Naturales Protegidas, part of the Secretaria de Medioambiente y Recursos Naturales. The Klamath National Forest Forest has cooperated with its Mexican counterparts since 1993 in natural resource management, neo-tropical bird inventories, wildfire management, and more recently in watershed analyses. Rates of sedimentation are estimated from bathymetric surveys conducted in March, 2002. A longitudinal profile down the inundated canyon during a high reservoir level shows an inflection from a slope of 0.0017 to one of 0.0075 at 7.2 km downstream of the mouth of Rio Negro. The bed elevation at this point corresponds to the lowest reservoir level, suggesting that the gentler sloping bed upstream is formed by fluvial processes during drawdown and that downstream by pluvial processes. Using accounts that boats could access Rio Negro during low water levels in 1984, we estimate an annual sedimentation rate of roughly 3 million cubic meters per year. This suggests that boats might no longer be able to access the most spectacular section of canyon upstream of Rio Negro within a decade, depending on how the

  15. Submarine canyons along the upper Sardinian slope (Central Western Mediterranean) as repositories for derelict fishing gears.

    Science.gov (United States)

    Cau, Alessandro; Alvito, Andrea; Moccia, Davide; Canese, Simonepietro; Pusceddu, Antonio; Rita, Cannas; Angiolillo, Michela; Follesa, Maria C

    2017-10-15

    By means of ROV surveys, we assessed the quantity, composition and bathymetric distribution of marine litter in 17 sites along the Sardinian continental margin (Central Western Mediterranean) at depths ranging from 100 to 480m. None of the investigated sites was litter free, but the mean density of litter (0.0175±0.0022itemsm -2 ) was lower than that reported from other Tyrrhenian regions. The difference in the total litter density among sites was negligible, but the density of derelict fishing gear (DFG) items (most of which ascribable to small scale fishery) in submarine canyons was higher in submarine canyons than in other habitats. Our result suggest that submarine canyons (known to be highly vulnerable ecosystems) act as major repositories of DFGs, and, therefore, we anticipate the need of specific measures aimed at minimizing the loss and abandonment of DFGs in submarine canyons. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Modeled alongshore circulation and morphologic evolution onshore of a large submarine canyon

    Science.gov (United States)

    Hansen, J. E.; Raubenheimer, B.; List, J. H.; Elgar, S.; Guza, R. T.; Lippmann, T. C.

    2012-12-01

    Alongshore circulation and morphologic evolution observed at an ocean beach during the Nearshore Canyon Experiment, onshore of a large submarine canyon in San Diego, CA (USA), are investigated using a two-dimensional depth-averaged numerical model (Delft3D). The model is forced with waves observed in ~500 m water depth and tidal constituents derived from satellite altimetry. Consistent with field observations, the model indicates that refraction of waves over the canyon results in wave focusing ~500 m upcoast of the canyon and shadowing onshore of the canyon. The spatial variability in the modeled wave field results in a corresponding non-uniform alongshore circulation field. In particular, when waves approach from the northwest the alongshore flow converges near the wave focal zone, while waves that approach from the southwest result in alongshore flow that diverges away from the wave focal zone. The direction and magnitude of alongshore flows are determined by a balance between the (often opposing) radiation stress and alongshore pressure gradients, consistent with observations and previous results. The largest observed morphologic evolution, vertical accretion of about 1.5 m in about 3 m water depth near the wave focal zone, occurred over a one-week period when waves from the northwest reached heights of 1.8 m. The model, with limited tuning, replicates the magnitude and spatial extent of the observed accretion and indicates that net accretion of the cross-shore profile was owing to alongshore transport from converging alongshore flows. The good agreement between the observed and modeled morphology change allows for an in-depth examination of the alongshore force balance that resulted in the sediment convergence. These results indicate that, at least in this case, a depth-averaged hydrodynamic model can replicate observed surfzone morphologic change resulting from forcing that is strongly non-uniform in the alongshore. Funding was provided by the Office of Naval

  17. Effect of submarine canyons on tsunami heights, currents and run-up off the southeast coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    JayaKumar, S.; ManiMurali, R.; Baldock, T.E.

    Tsunami numerical model studies are mostly focused on inundation and run-up onto the coast. Fewer studies have been aimed at investigating role of submarine canyons on the tsunami heights, currents and run-up. The influence of submarine canyons...

  18. Correspondence of perceived vs. objective proximity to parks and their relationship to park-based physical activity

    Directory of Open Access Journals (Sweden)

    Kaczynski Andrew T

    2009-08-01

    Full Text Available Abstract Background Parks are key environmental resources for encouraging population-level physical activity (PA. In measuring availability of parks, studies have employed both self-reported and objective indicators of proximity, with little correspondence observed between these two types of measures. However, little research has examined how the degree of correspondence between self-reported and objectively-measured distance to parks is influenced by individual, neighborhood, and park-related variables, or which type of measure is more strongly related to physical activity outcomes. Methods We used data from 574 respondents who reported the distance to their closest park and compared this with objective measurements of proximity to the closest park. Both indicators were dichotomized as having or not having a park within 750 m. Audits of all park features within this distance were also conducted and other personal characteristics and neighborhood context variables (safety, connectedness, aesthetics were gleaned from participants' survey responses. Participants also completed detailed seven-day PA log booklets from which measures of neighborhood-based and park-based PA were derived. Results Agreement was poor in that only 18% of respondents achieved a match between perceived and objective proximity to the closest park (kappa = 0.01. Agreement was higher among certain subgroups, especially those who reported engaging in at least some park-based PA. As well, respondents with a greater number of parks nearby, whose closest park had more features, and whose closest park contained a playground or wooded area were more likely to achieve a match. Having a ball diamond or soccer field in the closest park was negatively related to achieving a match between perceived and objective proximity. Finally, engaging in at least some park-based PA was not related to either perceived or objective proximity to a park, but was more likely when a match between and

  19. Study of traffic-related pollutant removal from street canyon with trees: dispersion and deposition perspective.

    Science.gov (United States)

    Morakinyo, Tobi Eniolu; Lam, Yun Fat

    2016-11-01

    Numerical experiments involving street canyons of varying aspect ratio with traffic-induced pollutants (PM 2.5 ) and implanted trees of varying aspect ratio, leaf area index, leaf area density distribution, trunk height, tree-covered area, and tree planting pattern under different wind conditions were conducted using a computational fluid dynamics (CFD) model, ENVI-met. Various aspects of dispersion and deposition were investigated, which include the influence of various tree configurations and wind condition on dispersion within the street canyon, pollutant mass at the free stream layer and street canyon, and comparison between mass removal by surface (leaf) deposition and mass enhancement due to the presence of trees. Results revealed that concentration level was enhanced especially within pedestrian level in street canyons with trees relative to their tree-free counterparts. Additionally, we found a dependence of the magnitude of concentration increase (within pedestrian level) and decrease (above pedestrian level) due to tree configuration and wind condition. Furthermore, we realized that only ∼0.1-3 % of PM 2.5 was dispersed to the free stream layer while a larger percentage (∼97 %) remained in the canyon, regardless of its aspect ratio, prevailing wind condition, and either tree-free or with tree (of various configuration). Lastly, results indicate that pollutant removal due to deposition on leaf surfaces is potentially sufficient to counterbalance the enhancement of PM 2.5 by such trees under some tree planting scenarios and wind conditions.

  20. Canyon air flow measurement utilizing ASME standard pitot tube arrays

    International Nuclear Information System (INIS)

    Moncrief, B.R.

    1990-01-01

    The Savannah River Site produces nuclear materials for national defense. In addition to nuclear reactors, the site has separation facilities for reprocessing irradiated nuclear fuel. The chemical separation of highly radioactive materials takes place by remote control in large buildings called canyons. Personnel in these buildings are shielded from radiation by thick concrete walls. Contaminated air is exhausted from the canyons and contaminants are removed by sand filters prior to release to the atmosphere through a stack. When these facilities were built on a crash basis in the early 1950's, inadequate means were provided for pressure and air flow measurement. This presentation describes the challenge we faced in retrofitting a highly radioactive, heavily shielded facility with instrumentation to provide this capability

  1. Parking taxes : evaluating options and impacts

    International Nuclear Information System (INIS)

    Litman, T.A.

    2006-01-01

    In addition to encouraging the use of alternative modes of transport, parking taxes can help to reduce congestion, air pollution, and urban sprawl. Various types of parking taxes were evaluated in this paper, as well as their impacts on parking supply, prices and travel patterns. Examples of various parking tax programs in major cities in Canada, Europe, the United States and Australia were presented. Parking tax programs were divided into 2 main categories: (1) per-space parking levies which distribute cost burdens and encourage property owners to manage parking supply more efficiently and (2) commercial parking taxes on parking rental transactions which discourage the pricing of parking and concentrate impacts in limited areas. Worksite parking levies were discussed, as well stormwater fees and employee parking as a taxable benefit. Typical parking facility financial costs were reviewed and best practices for structuring and implementing parking taxes to increase public acceptability were outlined. It was suggested that the tax base should be broad and well-defined. Local governments should increase parking prices to market rates before imposing special parking taxes, and taxes and fees should be structured to avoid undesirable land use. Parking tax reforms should be part of an overall parking and mobility management program. Stakeholders should be consulted to insure that regulations, administrative procedures and enforcement policies are efficient and fair. The establishment of an evaluation program to determine tax impacts on parking supply and pricing, economic activity, traffic and spillover problems was also recommended. 42 refs., 4 tabs., 1 fig

  2. The on-street parking premium and car drivers' choice between street and garage parking

    NARCIS (Netherlands)

    Kobus, M.B.W.; Gutierrez Puigarnau, E.; Rietveld, P.; van Ommeren, J.N.

    2013-01-01

    We introduce a methodology to estimate the effect of parking prices on car drivers' choice between street and garage parking. Our key identifying assumption is that the marginal benefit of parking duration does not depend on this choice. The endogeneity of parking duration is acknowledged in the

  3. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.H., E-mail: hlh@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Huo, R.; Yang, D. [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2009-07-15

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons-a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  4. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow.

    Science.gov (United States)

    Hu, L H; Huo, R; Yang, D

    2009-07-15

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons--a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  5. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

    International Nuclear Information System (INIS)

    Hu, L.H.; Huo, R.; Yang, D.

    2009-01-01

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons-a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  6. Repeat Mapping in the Lower Monterey Submarine Canyon Sheds Light on Morphological Change During Discrete Sediment Density Flow Events

    Science.gov (United States)

    Anderson, K.; Lundsten, E. M.; Caress, D. W.; Thomas, H. J.; Paull, C. K.; Maier, K. L.; Gales, J. A.; Gwiazda, R.; Talling, P.; Xu, J.; Parsons, D. R.

    2017-12-01

    The Coordinated Canyon Experiment (CCE), a multi-institutional collaboration effort, was designed to monitor the passage of sediment density flows along the axis of Monterey Canyon, offshore California, between 200 and 1850 m water depth. An array of moorings and sensors were deployed for three 6-month periods from October 2015 to April 2017. Aligned with the CCE deployments, repeat high-resolution multibeam bathymetric surveys of the Monterey Canyon floor were conducted with a mapping AUV (Autonomous Underwater Vehicle). The AUV carried a Reson 7125 multibeam echosounder (vertical precision of 0.15 m and horizontal resolution of 1.0 m). An inertial navigation system combined with a Doppler velocity logger allowed the AUV to fly pre-programmed grids at 3 knots, while maintaining an altitude of 50 m above the seafloor, to obtain a nominal line spacing of 130 m. The floor and lower flanks of the canyon between 200 to 540 m and 1350 to 1880 m water depths were mapped six times during the CCE. These repeat maps are subtracted to create bathymetry difference grids to show morphological change. Coupling the sensor observations with the bathymetric surveys, the CCE successfully documented sediment density flow events as well as the associated changes in seafloor morphology. Between repeat surveys, three sediment density flow events reached the lower canyon, extending to at least 1850 m water depth. On January 15, 2016, a particularly large density flow traveled more than 50 km down Monterey Canyon. Unlike in the upper canyon where this event caused wholesale reorganization of geomorphological features, changes to the lower canyon morphology involved a more moderate re-sculpting of the features. The effect of a sediment density flow of known magnitude and duration on the seafloor morphology has never been documented in a deep-sea setting before.

  7. Numerical study on the impact of ground heating and ambient wind speed on flow fields in street canyons

    Science.gov (United States)

    Li, Lei; Yang, Lin; Zhang, Li-Jie; Jiang, Yin

    2012-11-01

    The impact of ground heating on flow fields in street canyons under different ambient wind speed conditions was studied based on numerical methods. A series of numerical tests were performed, and three factors including height-to-width (H/W) ratio, ambient wind speed and ground heating intensity were taken into account. Three types of street canyon with H/W ratios of 0.5, 1.0 and 2.0, respectively, were used in the simulation and seven speed values ranging from 0.0 to 3.0 m s-1 were set for the ambient wind speed. The ground heating intensity, which was defined as the difference between the ground temperature and air temperature, ranged from 10 to 40 K with an increase of 10 K in the tests. The results showed that under calm conditions, ground heating could induce circulation with a wind speed of around 1.0 m s-1, which is enough to disperse pollutants in a street canyon. It was also found that an ambient wind speed threshold may exist for street canyons with a fixed H/W ratio. When ambient wind speed was lower than the threshold identified in this study, the impact of the thermal effect on the flow field was obvious, and there existed a multi-vortex flow pattern in the street canyon. When the ambient wind speed was higher than the threshold, the circulation pattern was basically determined by dynamic effects. The tests on the impact of heating intensity showed that a higher ground heating intensity could strengthen the vortical flow within the street canyon, which would help improve pollutant diffusion capability in street canyons.

  8. Morphology, sedimentary features and evolution of a large palaeo submarine canyon in Qiongdongnan basin, Northern South China Sea

    Science.gov (United States)

    Li, Xiangquan; Fairweather, Luke; Wu, Shiguo; Ren, Jianye; Zhang, Hongjie; Quan, Xiayun; Jiang, Tao; Zhang, Cheng; Su, Ming; He, Yunlong; Wang, Dawei

    2013-01-01

    The large Miocene-aged palaeo canyon that extents through the Qiongdongnan basin (QDNB) and Yinggehai basin (YGHB) of Northern South China Sea has been of considerable interest both economically and scientifically over the past decade. Stemmed from this, significant research has been employed into understanding the mechanism for its existence, incision, and sedimentary fill, yet debate remains. In the first case the canyon itself is actually quite anomalous. Alone from the size (over 570 km in length and more than 8 km in width (Yuan et al., 2009)), which is considerably more than most ancient deep-water channels (REFS), the canyon's sedimentary fill is also distinctly different. Some explanations have been given to explain the canyon's origin and existence, these include increased sediment supply from the Red River which is genetically linked to uplift of the Tibetan Plateau, lowstand turbidite and mass-transport activity, reactivation and dextral displacement of the Red River Fault zone inducing erosive gravity-flows, regional tilt of the QDNB and YGHB, paleo-seafloor morphology and seal-level fluctuations. With the application of new data obtained from interpretations of a large number of 2D seismic profiles, core and well log data, and tectonic and sedimentary analysis this contribution aims to: (1) Present models to explain the Canyon's sedimentary fill and basin plain deposits, which provided significant understanding of processes pre-, syn- and post-incision and; (2) review the plausibility and likelihood of each of the controlling mechanisms, hoping to shed light on this controversial aspect. We conclude that the final erosive event that shaped the canyon is dated at 5.5 Ma. The Canyon's unusual fill is a product of variation in the interaction between turbidity currents and MTD that blocked the canyon's axis, and the reduction in gravity flow energy through time; and therefore the complete succession represents one major erosive and cut event at 5.5 Ma and

  9. Effects of High-Flow Experiments from Glen Canyon Dam on Abundance, Growth, and Survival Rates of Early Life Stages of Rainbow Trout in the Lees Ferry Reach of the Colorado River

    Science.gov (United States)

    Korman, Josh; Kaplinski, Matthew; Melis, Theodore S.

    2010-01-01

    High-flow experiments (HFEs) from Glen Canyon Dam are primarily intended to conserve fine sediment and improve habitat conditions for native fish in the Colorado River as it flows through Grand Canyon National Park, Arizona. These experimental flows also have the potential to affect the rainbow trout (Oncorhynchus mykiss) population in the Lees Ferry tailwater reach immediately below the dam, which supports a highly valued recreational fishery and likely influences the abundance of rainbow trout in Grand Canyon. Understanding how flow regimes affect the survival and growth of juvenile rainbow trout is critical to interpreting trends in adult abundance. This study reports on the effects of HFEs in 2004 and 2008 on early life stages of rainbow trout in the Lees Ferry reach on the basis of monthly sampling of redds (egg nests) and the abundance of the age-0 trout (fertilization to about 1 to 2 months from emergence) and their growth during a 7-year period between 2003 and 2009. Multiple lines of evidence indicate that the March 2008 HFE resulted in a large increase in early survival rates of age-0 trout because of an improvement in habitat conditions. A stock-recruitment analysis demonstrated that age-0 abundance in July 2008 was more than fourfold higher than expected, given the number of viable eggs that produced these fish. A hatch-date analysis showed that early survival rates were much higher for cohorts that hatched about 1 month after the 2008 HFE (about April 15, 2008) relative to those fish that hatched before this date. These cohorts, fertilized after the 2008 HFE, would have emerged into a benthic invertebrate community that had recovered, and was possibly enhanced by, the HFE. Interannual differences in growth of age-0 trout, determined on the basis of otolith microstructure, support this hypothesis. Growth rates in the summer and fall of 2008 (0.44 mm/day) were virtually the same as in 2006 (0.46 mm/day), the highest recorded during 6 years, even though

  10. 76 FR 66034 - Proposed Foreign-Trade Zone-Ada and Canyon Counties, ID, Under Alternative Site Framework...

    Science.gov (United States)

    2011-10-25

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Docket 65-2011] Proposed Foreign-Trade Zone--Ada... establish a general-purpose foreign-trade zone at sites in Ada and Canyon Counties, Idaho, adjacent to the... proposed service area under the ASF would be Ada and Canyon Counties, Idaho. If approved, the applicant...

  11. Semi-automatic parking slot marking recognition for intelligent parking assist systems

    Directory of Open Access Journals (Sweden)

    Ho Gi Jung

    2014-01-01

    Full Text Available This paper proposes a semi-automatic parking slot marking-based target position designation method for parking assist systems in cases where the parking slot markings are of a rectangular type, and its efficient implementation for real-time operation. After the driver observes a rearview image captured by a rearward camera installed at the rear of the vehicle through a touchscreen-based human machine interface, a target parking position is designated by touching the inside of a parking slot. To ensure the proposed method operates in real-time in an embedded environment, access of the bird's-eye view image is made efficient: image-wise batch transformation is replaced with pixel-wise instantaneous transformation. The proposed method showed a 95.5% recognition rate in 378 test cases with 63 test images. Additionally, experiments confirmed that the pixel-wise instantaneous transformation reduced execution time by 92%.

  12. Smart Parking Management Field Test: A Bay Area Rapid Transit (BART) District Parking Demonstration

    OpenAIRE

    Shaheen, Susan

    2005-01-01

    In almost every major city in the U.S. and internationally, parking problems are ubiquitous. It is well known that the limited availability of parking contributes to roadway congestion, air pollution, and driver frustration and that the cost of expanding traditional parking capacity is frequently prohibitive. However, less research has addressed the effect of insufficient parking at transit stations on transit use. In the San Francisco Bay Area, parking has recently been at or near capacity a...

  13. A Cross-Sectional Investigation of the Importance of Park Features for Promoting Regular Physical Activity in Parks.

    Science.gov (United States)

    Costigan, Sarah A; Veitch, Jenny; Crawford, David; Carver, Alison; Timperio, Anna

    2017-11-02

    Parks in the US and Australia are generally underutilised, and park visitors typically engage in low levels of physical activity (PA). Better understanding park features that may encourage visitors to be active is important. This study examined the perceived importance of park features for encouraging park-based PA and examined differences by sex, age, parental-status and participation in PA. Cross-sectional surveys were completed by local residents ( n = 2775) living near two parks (2013/2015). Demographic variables, park visitation and leisure-time PA were self-reported, respondents rated the importance of 20 park features for encouraging park-based PA in the next fortnight. Chi-square tests of independence examined differences in importance of park features for PA among sub-groups of local residents (sex, age, parental-status, PA). Park features ranked most important for park-based PA were: well maintained (96.2%), feel safe (95.4%), relaxing atmosphere (91.2%), easy to get to (91.7%), and shady trees (90.3%). All subgroups ranked 'well maintained' as most important. Natural and built environment features of parks are important for promoting adults' park-based PA, and should be considered in park (re)design.

  14. The impact of traffic-flow patterns on air quality in urban street canyons.

    Science.gov (United States)

    Thaker, Prashant; Gokhale, Sharad

    2016-01-01

    We investigated the effect of different urban traffic-flow patterns on pollutant dispersion in different winds in a real asymmetric street canyon. Free-flow traffic causes more turbulence in the canyon facilitating more dispersion and a reduction in pedestrian level concentration. The comparison of with and without a vehicle-induced-turbulence revealed that when winds were perpendicular, the free-flow traffic reduced the concentration by 73% on the windward side with a minor increase of 17% on the leeward side, whereas for parallel winds, it reduced the concentration by 51% and 29%. The congested-flow traffic increased the concentrations on the leeward side by 47% when winds were perpendicular posing a higher risk to health, whereas reduced it by 17-42% for parallel winds. The urban air quality and public health can, therefore, be improved by improving the traffic-flow patterns in street canyons as vehicle-induced turbulence has been shown to contribute significantly to dispersion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A decision support tool for evaluating the air quality and wind comfort induced by different opening configurations for buildings in canyons.

    Science.gov (United States)

    Fan, M; Chau, C K; Chan, E H W; Jia, J

    2017-01-01

    This study formulated a new index for evaluating both the air quality and wind comfort induced by building openings at the pedestrian level of street canyons. The air pollutant concentrations and wind velocities induced by building openings were predicted by a series of CFD simulations using ANSYS Fluent software based on standard k-ɛ model. The types of opening configurations investigated inside isolated and non-isolated canyons included separations, voids and permeable elements. It was found that openings with permeability values of 10% were adequate for improving the air quality and wind comfort conditions for pedestrians after considering the reduction in development floor areas. Openings were effective in improving the air quality in isolated canyons and different types of opening configurations were suggested for different street aspect ratios. On the contrary, openings were not always found effective for non-isolated canyons if there were pollutant sources in adjacent street canyons. As such, it would also be recommended introducing openings to adjacent canyons along with openings to the target canyons. The formulated index can help city planners and building designers to strike an optimal balance between air quality and wind comfort for pedestrians when designing and planning buildings inside urban streets and thus promoting urban environmental sustainability. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Modelling parking behaviour considering heterogeneity

    Energy Technology Data Exchange (ETDEWEB)

    San Martin, G.A.; Ibeas Portilla, A.; Alonso Oreña, B.; Olio, L. del

    2016-07-01

    Most of motorized trips in cities of middle and small size are made in public transport and mainly in private vehicle, this has caused a saturation in parking systems of the cities, causing important problems to society, one of the most important problems is high occupancy of public space by parking systems. Thus, is required the estimation of models that reproduce users’ behaviour when they are choosing for parking in cities, to carry out transport policies to improve transport efficiency and parking systems in the cities. The aim of this paper is the specification and estimation of models that simulate users’ behaviour when they are choosing among alternatives of parking that there are in the city: free on street parking, paid on street parking, paid on underground parking and Park and Ride (now there isn´t). For this purpose, is proposed a multinomial logit model that consider systematic and random variations in tastes. Data of users’ behaviour from the different alternatives of parking have been obtained with a stated preference surveys campaign which have been done in May 2015 in the principal parking zones of the city of Santander. In this paper, we provide a number of improvements to previously developed methodologies because of we consider much more realism to create the scenarios stated preference survey, obtaining better adjustments. (Author)

  17. Impacts of national parks on tourism: a case study from a prominent alpine national park

    International Nuclear Information System (INIS)

    Getzner, M.

    2008-01-01

    National parks and other categories of protected areas are often assumed to enhance regional economic development due to park tourism. The current study attempts to estimate the impact of the Hohe Tauern national park (Austria) on tourism by exploring whether and to what extent the national park may have had an influence on tourism development. For most national park communities, the results suggest that the establishment of the national park had some impact by enforcing an already positive trend or by weakening or reversing a negative trend of tourism. However, breakpoint tests exhibit turning points up to several years after the establishment of the park, indicating that taking a national park as the basis for tourism development is a medium to long term development strategy. In the short term, the impact of a national park on tourism is not measurable. Tourism increased by 1 to 3% annually after the breakpoint, indicating that the establishment of a national park has to be incorporated into the tourism and development strategy of a region right from the start. The causal relationship between the establishment of the national park and tourism development may be weak, in particular in communities where the difference between the actual and the forecast numbers of overnight stays is small. Marketing national park tourism and building up a brand or distinctive label may therefore contribute to regional development particularly in the long term. [it

  18. New supply for canyon fire foam system

    International Nuclear Information System (INIS)

    Gainey, T.

    1995-01-01

    The raw water supply for the B-Plant Canyon fire foam system is being replaced. The 4 inche water supply line to the foam system is being rerouted from the 6 inches raw water line in the Pipe Gallery to the 10 inches raw water main in the Operating Gallery. This document states the acceptance criteria for the flushing and testing to be performed by the contractor

  19. Parking Spoorzone Delft : Addressing expected parking challenges 2015-2017

    NARCIS (Netherlands)

    Piccot, C.; Groenendijk, L.; Rot, M.; Van der Meijs, P.; Rakers, T.; Negenborn, R.R.; Annema, J.A.; Pel, A.; Vleugel, J.

    2014-01-01

    This project is carried out on request of the BVOW, the interest group of the neighbourhoods Olofsbuurt and Westerkwartier in Delft, in order to propose solutions for the parking issue of Spoorzone Delft expected between 2015 and 2017. They are worried that parking disturbances will emerge in their

  20. Analysis of F-Canyon Effluents During the Dissolution Cycle with a Fourier Transform Infrared Spectrometer/Multipath Cell

    International Nuclear Information System (INIS)

    Villa, E.

    1999-01-01

    Air samples from F-Canyon effluents were collected at the F-Canyon stack and transported to a laboratory at the Savannah River Technology Center (SRTC) for analysis using a Fourier transform infrared spectrometer in conjunction with a multipath cell. Air samples were collected during the decladding and acid cuts of the dissolution of the irradiated aluminum-cladded slugs. The FTIR analyses of the air samples show the presence of NO2, NO, HNO2, N2O, SF6, and 85Kr during the dissolution cycle. The concentration time profiles of these effluents corresponded with expected release rates from the F-Canyon operations

  1. Seasonal pathways of organic matter within the Avilés submarine canyon: Food web implications

    Science.gov (United States)

    Romero-Romero, Sonia; Molina-Ramírez, Axayacatl; Höfer, Juan; Duineveld, Gerard; Rumín-Caparrós, Aitor; Sanchez-Vidal, Anna; Canals, Miquel; Acuña, José Luis

    2016-11-01

    The transport and fate of organic matter (OM) sources within the Avilés submarine canyon (Cantabrian Sea, Southern Bay of Biscay) were studied using carbon and nitrogen stable isotope ratios. The isotopic composition of settling particles and deep bottom sediments closely resembled that of surface particulate OM, and there were no marked differences in the isotopic composition of settling particles inside and outside of the AC. This indicates that the Avilés Canyon (AC) receives inputs of sinking OM mostly from the upper water column and less through advective near-bottom down-canyon transport. Sinking OM fluxes are of marine and terrestrial origin in proportions which vary seasonally. Analysis of δ13C in the canyon fauna indicates a dependence on OM mainly produced by marine phytoplankton. A tight coupling of isotopic signatures between pelagic organisms and benthic suspension feeders reflects an active biological vertical transport of OM from the surface to the deep-sea. The food web presented seasonal variations in the trophic niche width and the amplitude of the primary carbon sources, reflecting seasonality in the availability of fresh particulate OM. Those seasonal changes are larger for benthic organisms of lower trophic levels.

  2. Aerial radiological survey of the Diablo Canyon Nuclear Power Plant and surrounding area, Diablo Canyon, California. Date of survey: September-October 1984

    International Nuclear Information System (INIS)

    1985-03-01

    An aerial radiological survey was conducted over the area surrounding the Diablo Canyon Nuclear Power Plant in Diablo Canyon, California. The survey was conducted between 20 September and 3 October 1984. A series of flight lines parallel to the coastline were flown at an altitude of 91 meters (300 feet) and were spaced 152 meters (500 feet) apart. The survey covered an area of 250 square kilometers (100 square miles). The resulting background exposure rates over the survey area ranged from 5 to 21 microroentgens per hour (μR/h). The reported exposure rate values include an estimated cosmics ray contribution of 3.6 μR/h. Soil samples were also collected at several locations within the survey areas and analyzed in the laboratory for isotopic composition. The results of the survey showed only the presence of naturally occurring background radiation. No man-made radioactivity was detected. 4 refs., 4 figs., 4 tabs

  3. Biological and Management Implications of Fire-Pathogen Interactions in the Giant Sequoia Ecosystem

    Science.gov (United States)

    Douglas D. Piirto; John R. Parmeter; Fields W. Cobb; Kevin L. Piper; Amy C. Workinger; William J. Otrosina

    1998-01-01

    An overriding management goal for national parks is the maintenance or, where necessary, the restoration of natural ecological processes. In Sequoia-Kings Canyon and Yosemite National Parks, there is concern about the effects of fire suppression on the giant sequoia-mixed conifer forest ecosystem. The National Park Service is currently using prescribed fire management...

  4. Spatial analysis related to the location characteristics of park supply. Case study: Music Park and Pendawa Park, Bandung City, Indonesia

    Science.gov (United States)

    Malik, A.; Akbar, R.; Maryati, S.; Natalivan, P.

    2018-05-01

    Public space plays a role in defining the character of a city and is a valuable asset for a city and one of the indicators in assessing whether a city is considered successful or not. In the context of urban sociology, high-quality public spaces with well-maintained environments can improve the quality of the heterogeneous life of urban social communities by creating economic, social, or environmental value-added. Urban societies tend to be heterogeneous, individualistic, and characterized by high competition that often causes conflicts. Another reason for conflicts is the relatively high social differentiation because of the level of religious differences, customs, languages, and sociocultural aspects brought by immigrants from various regions. In the context of space, the city is a system that does not stand alone because internally the city is a unified system of functional activities in it. Meanwhile, externally, the city is influenced by its surrounding environment. As part of the public space, park has an important role in the environmental, aesthetic, recreational, psychological, social, educational, and economic aspects of the city. Public space can be understood as open spaces in urban areas, where everyone regardless their interests and backgrounds can be intersectional and have social contact and serve as an “urban regenerator” including educational functions through innovation and technological intervention. Moreover, park can also absorb carbon dioxide emissions, produce oxygen, improve air and water quality, regulate the microclimate, reduce noise, protect soil and water, and maintain biodiversity. However, many things cause the function of parks to decrease. One reason relates to the distribution of parks related to the characteristics of their location. Research has not seen many studies on the characteristics of locations in the planning of public space. The provision of public space should consider these location characteristics. This study

  5. Interview with Steve Parks

    Science.gov (United States)

    Hitchcock, Jennifer

    2016-01-01

    Jennifer Hitchcock interviews community activist and director of Syracuse University's Composition and Cultural Rhetoric doctoral program, Steve Parks. They discuss Parks's working-class background, career path, influences, and activism. Parks also considers the direction of the field of composition and rhetoric and expresses optimism for the…

  6. Characterization of traffic-related PM concentration distribution and fluctuation patterns in near-highway urban residential street canyons.

    Science.gov (United States)

    Hahn, Intaek; Brixey, Laurie A; Wiener, Russell W; Henkle, Stacy W; Baldauf, Richard

    2009-12-01

    Analyses of outdoor traffic-related particulate matter (PM) concentration distribution and fluctuation patterns in urban street canyons within a microscale distance of less than 500 m from a highway source are presented as part of the results from the Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) study. Various patterns of spatial and temporal changes in the street canyon PM concentrations were investigated using time-series data of real-time PM concentrations measured during multiple monitoring periods. Concurrent time-series data of local street canyon wind conditions and wind data from the John F. Kennedy (JFK) International Airport National Weather Service (NWS) were used to characterize the effects of various wind conditions on the behavior of street canyon PM concentrations.Our results suggest that wind direction may strongly influence time-averaged mean PM concentration distribution patterns in near-highway urban street canyons. The rooftop-level wind speeds were found to be strongly correlated with the PM concentration fluctuation intensities in the middle sections of the street blocks. The ambient turbulence generated by shifting local wind directions (angles) showed a good correlation with the PM concentration fluctuation intensities along the entire distance of the first and second street blocks only when the wind angle standard deviations were larger than 30 degrees. Within-canyon turbulent shearing, caused by fluctuating local street canyon wind speeds, showed no correlation with PM concentration fluctuation intensities. The time-averaged mean PM concentration distribution along the longitudinal distances of the street blocks when wind direction was mostly constantly parallel to the street was found to be similar to the distribution pattern for the entire monitoring period when wind direction fluctuated wildly. Finally, we showed that two different PM concentration metrics-time-averaged mean

  7. Automated Car Park Management System

    Science.gov (United States)

    Fabros, J. P.; Tabañag, D.; Espra, A.; Gerasta, O. J.

    2015-06-01

    This study aims to develop a prototype for an Automated Car Park Management System that will increase the quality of service of parking lots through the integration of a smart system that assists motorist in finding vacant parking lot. The research was based on implementing an operating system and a monitoring system for parking system without the use of manpower. This will include Parking Guidance and Information System concept which will efficiently assist motorists and ensures the safety of the vehicles and the valuables inside the vehicle. For monitoring, Optical Character Recognition was employed to monitor and put into list all the cars entering the parking area. All parking events in this system are visible via MATLAB GUI which contain time-in, time-out, time consumed information and also the lot number where the car parks. To put into reality, this system has a payment method, and it comes via a coin slot operation to control the exit gate. The Automated Car Park Management System was successfully built by utilizing microcontrollers specifically one PIC18f4550 and two PIC16F84s and one PIC16F628A.

  8. Orlice Nature Park - environmental themes

    International Nuclear Information System (INIS)

    Hanus, L.

    2002-01-01

    The aim of this abstract is to outline the main characteristics of Orlice Nature Park and of the procedure of Environmental Impact Assessment (EIA), and to evaluate public interest in the nature park and in nature protection in general. Orlice Nature Park was instituted in 1996. The function of the park is to protect the character of the area of landscape around the River Orlice. Orlice Natural Park covers an area of 115 sq. km. The main environmental risks to the park are: intensive agriculture, forest mono-culture, industry, transport, channel improvement, the building of holiday cottages, sport, and recreation. Among the conflicts of interest in the park are: nature protection, water management, building constrictions, business, fishery, water sports and recreation. During the process of Environmental Impact Assessment in Hradec Kralove, the public voiced its opinion against the building of a supermarket within the grounds of of the nature park. In this case the public showed its interest in the value of nature and landscape, the value of human health and the value of plant species. In general, the public and the local media show an interest in the park only in exceptional circumstances. (author)

  9. Park It!

    Science.gov (United States)

    Sartorius, Tara Cady

    2010-01-01

    Many artists visit national parks to draw, paint and take photographs of some of the most amazing scenery on earth. Raw nature is one of the greatest inspirations to an artist, and artists can be credited for helping inspire the government to create the National Park System. This article features Thomas Moran (1837-1926), one of the artists who…

  10. iPark

    DEFF Research Database (Denmark)

    Yang, Bin; Fantini, Ernesto Nicolas; Jensen, Christian S.

    2013-01-01

    where the geo-spatial aspect is not just a tag on other content, but is the primary content, e.g., a city street map with up-to-date road construction data. Along these lines, the iPark system aims to turn volumes of GPS data obtained from vehicles into information about the locations of parking spaces...

  11. State Park Trails

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set is a collection of ArcView shapefiles (by park) of trails within statutory boundaries of individual MN State Parks, State Recreation Areas and State...

  12. The influence of controlled floods on fine sediment storage in debris fan-affected canyons of the Colorado River basin

    Science.gov (United States)

    Mueller, Erich R.; Grams, Paul E.; Schmidt, John C.; Hazel, Joseph E.; Alexander, Jason S.; Kaplinski, Matt

    2014-01-01

    Prior to the construction of large dams on the Green and Colorado Rivers, annual floods aggraded sandbars in lateral flow-recirculation eddies with fine sediment scoured from the bed and delivered from upstream. Flows greater than normal dam operations may be used to mimic this process in an attempt to increase time-averaged sandbar size. These controlled floods may rebuild sandbars, but sediment deficit conditions downstream from the dams restrict the frequency that controlled floods produce beneficial results. Here, we integrate complimentary, long-term monitoring data sets from the Colorado River in Marble and Grand Canyons downstream from Glen Canyon dam and the Green River in the Canyon of Lodore downstream from Flaming Gorge dam. Since the mid-1990s, several controlled floods have occurred in these canyon rivers. These controlled floods scour fine sediment from the bed and build sandbars in eddies, thus increasing channel relief. These changes are short-lived, however, as interflood dam operations erode sandbars within several months to years. Controlled flood response and interflood changes in bed elevation are more variable in Marble Canyon and Grand Canyon, likely reflecting more variable fine sediment supply and stronger transience in channel bed sediment storage. Despite these differences, neither system shows a trend in fine-sediment storage during the period in which controlled floods were monitored. These results demonstrate that controlled floods build eddy sandbars and increase channel relief for short interflood periods, and this response may be typical in other dam-influenced canyon rivers. The degree to which these features persist depends on the frequency of controlled floods, but careful consideration of sediment supply is necessary to avoid increasing the long-term sediment deficit.

  13. Ventilation Processes in a Three-Dimensional Street Canyon

    Czech Academy of Sciences Publication Activity Database

    Nosek, Štěpán; Kukačka, L.; Kellnerová, Radka; Jurčáková, Klára; Jaňour, Zbyněk

    2016-01-01

    Roč. 159, č. 2 (2016), s. 259-284 ISSN 0006-8314 R&D Projects: GA ČR GAP101/12/1554; GA ČR GA15-18964S Institutional support: RVO:61388998 Keywords : Coherent structures * line source * pollution flux measurements * street canyon * wind tunnel Subject RIV: BK - Fluid Dynamics Impact factor: 2.573, year: 2016

  14. Pulsars at Parkes

    OpenAIRE

    Manchester, R. N.

    2012-01-01

    The first pulsar observations were made at Parkes on March 8, 1968, just 13 days after the publication of the discovery paper by Hewish and Bell. Since then, Parkes has become the world's most successful pulsar search machine, discovering nearly two thirds of the known pulsars, among them many highly significant objects. It has also led the world in pulsar polarisation and timing studies. In this talk I will review the highlights of pulsar work at Parkes from those 1968 observations to about ...

  15. Parking Space Detection and Trajectory Tracking Control for Vehicle Auto-Parking

    OpenAIRE

    Shiuh-Jer Huang; Yu-Sheng Hsu

    2017-01-01

    On-board available parking space detecting system, parking trajectory planning and tracking control mechanism are the key components of vehicle backward auto-parking system. Firstly, pair of ultrasonic sensors is installed on each side of vehicle body surface to detect the relative distance between ego-car and surrounding obstacle. The dimension of a found empty space can be calculated based on vehicle speed and the time history of ultrasonic sensor detecting information. This result can be u...

  16. Vertical profiles of lung deposited surface area concentration of particulate matter measured with a drone in a street canyon.

    Science.gov (United States)

    Kuuluvainen, Heino; Poikkimäki, Mikko; Järvinen, Anssi; Kuula, Joel; Irjala, Matti; Dal Maso, Miikka; Keskinen, Jorma; Timonen, Hilkka; Niemi, Jarkko V; Rönkkö, Topi

    2018-05-23

    The vertical profiles of lung deposited surface area (LDSA) concentration were measured in an urban street canyon in Helsinki, Finland, by using an unmanned aerial system (UAS) as a moving measurement platform. The street canyon can be classified as an avenue canyon with an aspect ratio of 0.45 and the UAS was a multirotor drone especially modified for emission measurements. In the experiments of this study, the drone was equipped with a small diffusion charge sensor capable of measuring the alveolar LDSA concentration of particles. The drone measurements were conducted during two days on the same spatial location at the kerbside of the street canyon by flying vertically from the ground level up to an altitude of 50 m clearly above the rooftop level (19 m) of the nearest buildings. The drone data were supported by simultaneous measurements and by a two-week period of measurements at nearby locations with various instruments. The results showed that the averaged LDSA concentrations decreased approximately from 60 μm 2 /cm 3 measured close to the ground level to 36-40 μm 2 /cm 3 measured close to the rooftop level of the street canyon, and further to 16-26 μm 2 /cm 3 measured at 50 m. The high-resolution measurement data enabled an accurate analysis of the functional form of vertical profiles both in the street canyon and above the rooftop level. In both of these regions, exponential fits were used and the parameters obtained from the fits were thoroughly compared to the values found in literature. The results of this study indicated that the role of turbulent mixing caused by traffic was emphasized compared to the street canyon vortex as a driving force of the dispersion. In addition, the vertical profiles above the rooftop level showed a similar exponential decay compared to the profiles measured inside the street canyon. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Deposition and early hydrologic evolution of Westwater Canyon wet alluvial-fan system

    International Nuclear Information System (INIS)

    Galloway, W.E.

    1980-01-01

    The Westwater Canyon Member is one of several large, low-gradient alluvial fans that compose the Morrison Formation in the Four Corners area. Morrison fans were deposited by major laterally migrating streams entering a broad basin bounded by highlands to the west and south. The Westwater Canyon sand framework consists of a downfan succession of 1) proximal braided channel, 2) straight bed-load channel, 3) sinuous mixed-load channel, and 4) distributary mixed-load-channel sand bodies. Regional sand distribution and facies patterns are highly digitate and radiate from a point source located northwest of Gallup, New Mexico. Early ground-water flow evolution within the Westwater Canyon fan aquifer system can be inferred by analogy with Quaternary wet-fan deposits and by the interpreted paragenetic sequence of diagenetic features present. Syndepositional flow was controlled by the downfan hydrodynamic gradient and the high horizontal and vertical transmissivity of the sand-rich fan aquifer. Dissolution and transport of soluble humate would be likely in earliest ground water, which was abundant, fresh, and slightly alkaline. With increasing confinement of the aquifer below less permeable tuffaceous Brushy Basin deposits and release of soluble constituents from volcanic ash, flow patterns stabilized, and relatively more saline, uranium-rich ground water permeated the aquifer. Uranium mineralization occurred during this early postdepositional, semiconfined flow phase. Development of overlying Dakota swamps suggests a shallow water table indicative of regional dischare or stagnation. In either event, only limited downward flux of acidic water is recorded by local, bleached, kaolinized zones where the Westwater Canyon directly underlies the Dakota swamps. Subsequent ground-water flow phases have further obscured primary alteration patterns and caused local oxidation and redistribution of uranium

  18. High resolution morphobathymetric analysis and short-term evolution of the upper part of the Capbreton submarine canyon (south-east Bay of Biscay - French Atlantic coast)

    Science.gov (United States)

    Gillet, Hervé; Mazières, Alaïs; Mulder, Thierry; Cremer, Michel

    2013-04-01

    The Capbreton Canyon stands out by its deep incision through continental shelf and slope and its present turbidite activity. The head of the canyon is anthropically disconnected from the Adour River since 1310 AD, but is located close enough to the coast to allow a direct supply by longshore drift. Sedimentary processes in upper part of the Capbreton Canyon are poorly documented. Several evidences, including sandy slide scars in the head, suggest that this area plays a major role in triggering downstream gravity currents). However, no modern sedimentary activity in the upper canyon had so far been evidenced. Our study is based on the analysis and comparison of several sets of multibeam bathymetric data acquired in 1998, 2010 and 2012 (up to 1.5 m resolution). The morphobathymetric analysis brought the following key observations: - The upper part of the canyon is characterised by a meandering talweg underlined by two kinds of terraces: (1) small elongated terraces standing only 10 to 15 m above the talweg axis and (2) large terraces standing 45 to 100 m above the talweg axis. - The regular 1° longitudinal slope of the talweg is interrupted by several 10 m high knickpoints. - The floor of the talweg shows some rough areas scattered with transversal bedforms similar to the sediment waves described in the Monterey Canyon upper part (Smith et al, 2005). The morphological evolutions in the upper part of the canyon over the last 14 years especially affect the floor of the talweg: - Between 1998 and 2010, we observe a downstream succession of accretion areas (up to 11m thick) and erosion areas (reaching -25 m). The largest and highest terraces remain stable over this period, whereas the smallest and lowest elongated terraces show active sedimentation (+5 to +8 m). - Difference between 2010 and 2012 DEMs reveals three localized erosion spots corresponding to 200 m backward stepping of the knickpoints. Such observation confirms the active headward erosion in this part of

  19. Impacts of shape and height of upstream roof on airflow and pollutant dispersion inside an urban street canyon.

    Science.gov (United States)

    Huang, Yuan-Dong; He, Wen-Rong; Kim, Chang-Nyung

    2015-02-01

    A two-dimensional numerical model for simulating flow and pollutant dispersion in an urban street canyon is firstly developed using the FLUENT code and then validated against the wind tunnel results. After this, the flow field and pollutant dispersion inside an urban street canyon with aspect ratio W/H = 1 are examined numerically considering five different shapes (vaulted, trapezoidal, slanted, upward wedged, and downward wedged roofs) as well as three different roof height to building height ratios (Z H /H = 1/6, 1/3, and 1/2) for the upstream building roof. The results obtained reveal that the shape and height of an upstream roof have significant influences on flow pattern and pollutant distribution in an urban canyon. A large single clockwise vortex is generated in the canyon for the vaulted upstream roof at Z H /H = 1/6, 1/3, and 1/2, the trapezoidal and downward wedged roofs at Z H /H = 1/6 and 1/3, and the slanted and upward wedged roofs at Z H /H = 1/6, while a main clockwise vortex and a secondary counterclockwise vortex are established for the trapezoidal and downward wedged roofs at Z H /H = 1/2 and the slanted and upward wedged roofs at Z H /H = 1/3 and 1/2. In the one-vortex flow regime, the clockwise vortex moves upward and grows in size with increasing upstream roof height for the vaulted, trapezoidal, and downward wedged roofs. In the two-vortex flow regime, the size and rotational velocity of both upper clockwise and lower counterclockwise vortices increase with the upstream roof height for the slanted and upward wedged roofs. At Z H /H = 1/6, the pollution levels in the canyon are close among all the upstream roof shapes studied. At Z H /H = 1/3, the pollution levels in the canyon for the upward wedged roof and slanted roof are much higher than those for the vaulted, trapezoidal, and downward wedged roofs. At Z H /H = 1/2, the lowest pollution level appears in the canyon for the vaulted upstream roof, while

  20. Stratigraphic response across a structurally dynamic shelf: The latest guadalupian composite sequence at Walnut Canyon, New Mexico, U.S.A

    Science.gov (United States)

    Rush, J.; Kerans, C.

    2010-01-01

    The uppermost Yates and Tansill formations (Late Permian), as exposed along Walnut Canyon in Carlsbad Caverns National Park, New Mexico, USA, provide a unique opportunity to document the depositional architecture of a progradational, oversteepened, and mechanically failure-prone carbonate platform. Detailed facies mapping permitted critical assessment of depositional processes operating along this structurally dynamic platform margin. At the shelf crest, thick (12 m), vertically stacked fenestral-pisolite-tepee complexes indicate a stable shoreline. Early lithification of sediments and extensive cementation fostered rapid vertical accretion and allowed the shelf crest to easily adjust to base-level oscillations by stepping landward, stepping seaward, or aggrading. This production imbalance-in combination with syndepositional brittle failure and down-to-the-basin tilting(architecture, fracture properties, and a highly refined fusulinid biostratigraphic framework. Where fractures tip out, down-to-the-basin rotation is often observed with concurrent seaward thickening of overlying beds, indicating that such fractures functioned as a syndepositional hinge. A facies disjunction and horizontally juxtaposed fusulinid zonation were documented across an 80?? seaward-dipping dilational fracture filled with polymict breccia. An overlying damage zone consisting of spar-cemented fractures nested within silt-filled fractures illustrates periodic reactivation. Field relationships indicate that the dilational fracture approximates a paleoescarpment that resulted from catastrophic failure of the Capitan platform margin. Younger strata onlapped the paleoescarpment and gradually filled the reentrant. This mechanically compromised paleoescarpment was subsequently reactivated during the latest Guadalupian lowstand and was subaerially filled by siliciclastics and polymict breccia derived from the platform top. Results from Walnut Canyon indicate that shelf crest aggradation dominantly

  1. Public parks as urban tourism in Jakarta

    Science.gov (United States)

    Adiati, M. P.; Lestari, N. S.; Wiastuti, R. D.

    2018-03-01

    Sustainable urban tourism development should provide better places for people to live in and for people to visit. Jakarta as the capital city has a potential for its urban tourism. Thus, urban tourism attribute such as Public Park should be in high- quality to cope with the needs of urban people and outside visitors. The purpose of this study is to investigate Public Park attributes and to analyze its compliance refer to Public Park that eventually supports sustainable urban tourism. This paper used a qualitative approach. Primary data obtain from direct field observation in seven Public Parks in Jakarta; Menteng Park, Suropati Park, Situ Lembang Park, Ayodhya Park, Cattleya Park, Kodok Park, and Langsat Park. Observation checks list use as guidance. The result provides an assessment of Public Park based on four categories; the accessibility, park activities, safety, and user. The implication of this study offers recommendations to enhance Public Park so that it complies with good public park design- attributes and with the obligations of sustainable urban tourism in Jakarta.

  2. Improvement of Theme Park Marketing Mode:A Case Study of Theme Parks in Chengdu

    Institute of Scientific and Technical Information of China (English)

    Min; LI; Gaoli; XIONG

    2013-01-01

    Construction of theme park has been launched since the early 1990s in Chengdu City,but ended up as a losing proposition after its short-term prosperity because of similar scale and similarity with those in other cities.As more international well-known theme parks entering the market,theme parks in Chengdu have been faced with the transition,and novel concepts are also introduced into the operation of these parks.To adapt to the market,it is imperative to make marketing strategies and combine marketing elements.Through analyzing current development of local theme parks and introducing successful marketing modes of domestic and overseas theme parks,a favorable marketing mode for theme parks in Chengdu was defined on the basis of fully exploring Ba-Shu culture(Ba and Shu are two ancient kingdoms in the history of Sichuan).By defining a favorable theme,focusing more on visitors’experience,devoting more in developing new products,adopting flexible price strategies,and integrating advertisement marketing,internet marketing,and other marketing methods,outstanding brands will be formed,and tourism cultures with distinguished features of Chengdu will be created.

  3. USC Undergraduate Team Research, Geological Field Experience and Outdoor Education in the Tuolumne Batholith and Kings Canyon, High Sierra Nevada

    Science.gov (United States)

    Culbert, K. N.; Anderson, J. L.; Cao, W.; Chang, J.; Ehret, P.; Enriquez, M.; Gross, M. B.; Gelbach, L. B.; Hardy, J.; Paterson, S. R.; Ianno, A.; Iannone, M.; Memeti, V.; Morris, M.; Lodewyk, J.; Davis, J.; Stanley, R.; van Guilder, E.; Whitesides, A. S.; Zhang, T.

    2009-12-01

    Within four years, USC’s College of Letters, Arts and Sciences and Earth Science department have successfully launched the revolutionary undergraduate team research (UTR) program “Geologic Wonders of Yosemite at Two Miles High”. A diverse group of professors, graduate students and undergraduates spent two weeks mapping the Boyden Cave in Kings Canyon National Park, the Iron Mountain pendants south of Yosemite, the Western Metamorphic belt along the Merced River, and the Tuolumne Batholith (TB) in June and August 2009. During their experience in the field, the undergraduates learned geologic field techniques from their peers, professors, and experienced graduate students and developed ideas that will form the basis of the independent and group research projects. Apart from teaching undergraduates about the geology of the TB and Kings Canyon, the two weeks in the field were also rigorous exercise in critical thinking and communication. Every day spent in the field required complete cooperation between mentors and undergraduates in order to successfully gather and interpret the day’s data. Undergraduates were to execute the next day’s schedule and divide mapping duties among themselves. The two-week field experience was also the ideal setting in which to learn about the environmental impacts of their work and the actions of others. The UTR groups quickly adapted to the demanding conditions of the High Sierra—snow, grizzly bears, tourists, and all. For many of the undergraduates, the two weeks spent in the field was their first experience with field geology. The vast differences in geological experience among the undergraduates proved to be advantageous to the ‘team-teaching’ focus of the program: more experienced undergraduates were able to assist less experienced undergraduates while cementing their own previously gained knowledge about geology. Over the rest of the academic year, undergraduates will learn about the research process and scientific

  4. Smart parking management and navigation system

    KAUST Repository

    Saadeldin, Mohamed

    2017-11-09

    Various examples are provided for smart parking management, which can include navigation. In one example, a system includes a base station controller configured to: receive a wireless signal from a parking controller located at a parking space; determine a received signal strength indicator (RSSI) from the wireless signal; and identify a presence of a vehicle located at the parking space based at least in part on the RSSI. In another example, a method includes receiving a wireless signals from a base station controller and a parking controller located at a parking space; determining RSSIs from the wireless signals; and determining a location of the mobile computing device in a parking facility based at least in part on the RSSIs. In another example, a RSSI can be received, a parking occupancy can be determined using the RSSI, and an electronic record can be updated based on the parking occupancy.

  5. Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

    OpenAIRE

    Li, Xian-Xiang; Britter, Rex E.; Koh, Tieh Yong; Norford, Leslie Keith; Liu, Chun-Ho; Entekhabi, Dara; Leung, Dennis Y. C.

    2009-01-01

    Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification was produced by heating the ground of the street canyon. Using the Boussinesq approximation, thermal buoyancy forces were taken into account in both the Navier–Stokes equations and the transport equation for subgrid-scale turbulent kinetic energy (TKE). The LESs were valida...

  6. Logs and completion data for water and mass balance wells in Mortandad and Ten Site Canyons

    International Nuclear Information System (INIS)

    McLin, S.G.; Koch, R.J.

    1997-10-01

    Twenty-four monitoring wells were drilled and completed in December 1994 as part of a water and mass balance study for the shallow perched aquifer in the Mortandad Canyon alluvium and in the lower part of Ten-Site Canyon. The wells penetrated the alluvium containing the aquifer and were completed into the top of the weathered tuff. Twelve of these wells encountered the Tshirege Member (Cooing Unit 1 g) of the Bandelier Tuff below the canyon alluvium, while ten wells made contact with the Cerro Toledo interval, which lies between the Tshirege and Otowi Members of the Bandelier Tuff. The remaining two wells were completed into the alluvium above the weathered tuff contact. These wells provide access for continuous water level measurement and water sampling. Data from these new wells will be used to determine changes in alluvial aquifer water storage, water quality sampling, and estimation of seepage into the unsaturated Bandelier Tuff below the alluvium. This report documents drilling activities and well completion logs for the water and mass balance study. These wells also provide critical new data for fourteen north-south vertical cross-sections constructed for the canyon alluvium

  7. 36 CFR 7.70 - Glen Canyon National Recreation Area.

    Science.gov (United States)

    2010-07-01

    ... waters of, or Federally owned land administered by the National Park Service along the Colorado River... rafts on this section of the river, or while lining or portaging near rough water. One extra preserver... park waters or beach a PWC on park lands, except in the following areas: (i) On the Colorado River...

  8. Aerodynamic effects of trees on pollutant concentration in street canyons

    NARCIS (Netherlands)

    Buccolieri, R.; Gromke, C.B.; Sabatino, Di S.; Ruck, B.

    2009-01-01

    This paper deals with aerodynamic effects of avenue-like tree planting on flow and traffic-originated pollutant dispersion in urban street canyons by means of wind tunnel experiments and numerical simulations. Several parameters affecting pedestrian level concentration are investigated, namely plant

  9. Ecological baseline studies in Los Alamos and Guaje Canyons County of Los Alamos, New Mexico. A two-year study

    Energy Technology Data Exchange (ETDEWEB)

    Foxx, T.S. [comp.

    1995-11-01

    During the summers of 1993 and 1994, the Biological Resource Evaluations Team (BRET) of the Environmental Protection Group (ESH-8) conducted baseline studies within two canyon systems, Los Alamos and Guaje Canyons. Biological data was collected within each canyon to provide background and baseline information for Ecological Risk models. Baseline studies included establishment of permanent vegetation plots within each canyon along the elevational gradient. Then, in association with the various vegetation types, surveys were conducted for ground dwelling insects, birds, and small mammals. The stream channels associated with the permanent vegetation plots were characterized and aquatic macroinvertebrates collected within the stream monthly throughout a six-month period. The Geographic Position System (GPS) in combination with ARC INFO was used to map the study areas. Considerable data was collected during these surveys and are summarized in individual chapters.

  10. Smart Parking Management Pilot Project: A Bay Area Rapid Transit (BART) District Parking Demonstration

    OpenAIRE

    Shaheen, Susan; Rodier, Caroline; Eaken, Amanda M.

    2005-01-01

    This report presents early findings from an application of advanced parking technologies to maximize existing parking capacity at the Rockridge BART station, which was launched in December 2004 in the East San Francisco Bay Area. The smart parking system includes traffic sensors that count the number of vehicles entering and exiting the parking lots at the station. A reservation system allows travelers to reserve spaces by Internet, personal digital assistant (PDA), phone, and cell phone. The...

  11. Tidal and flood signatures of settling particles in the Gaoping submarine canyon (SW Taiwan) revealed from radionuclide and flow measurements

    Science.gov (United States)

    Huh, C.-A.; Liu, J.T.; Lin, H.-L.; Xu, J. P.

    2009-01-01

    Sediment transport and sedimentation processes in the Gaoping submarine canyon were studied using sediment trap and current meter moorings deployed at a location during the winter (January-March) and the summer (July-September) months in 2008. At the end of each deployment, sediment cores were also collected from the canyon floor at the mooring site. Samples from sediment traps and sediment cores were analyzed for 210Pb and 234Th by gamma spectrometry. In conjunction with particle size and flow measurements, the datasets suggest that sediment transport in the canyon is tidally-modulated in the drier winter season and flood (river)-dominated in the wetter summer season. From the magnitude and temporal variation of sediment flux in the canyon with respect to the burial flux and sediment budget on the open shelf and slope region, we reaffirm that, on annual or longer timescales, the Gaoping submarine canyon is an effective conduit transporting sediments from the Gaoping River's drainage basin (the source) to the deep South China Sea (the ultimate sink). ?? 2009 Elsevier B.V.

  12. A numerical study of diurnally varying surface temperature on flow patterns and pollutant dispersion in street canyons

    Science.gov (United States)

    Tan, Zijing; Dong, Jingliang; Xiao, Yimin; Tu, Jiyuan

    2015-03-01

    The impacts of the diurnal variation of surface temperature on street canyon flow pattern and pollutant dispersion are investigated based on a two-dimensional street canyon model under different thermal stratifications. Uneven distributed street temperature conditions and a user-defined wall function representing the heat transfer between the air and the street canyon are integrated into the current numerical model. The prediction accuracy of this model is successfully validated against a published wind tunnel experiment. Then, a series of numerical simulations representing four time scenarios (Morning, Afternoon, Noon and Night) are performed at different Bulk Richardson number (Rb). The results demonstrate that uneven distributed street temperature conditions significantly alters street canyon flow structure and pollutant dispersion characteristics compared with conventional uniform street temperature assumption, especially for the morning event. Moreover, air flow patterns and pollutant dispersion are greatly influenced by diurnal variation of surface temperature under unstable stratification conditions. Furthermore, the residual pollutant in near-ground-zone decreases as Rb increases in noon, afternoon and night events under all studied stability conditions.

  13. Seismic qualification of the rotary relay for use in the Trojan and Diablo Canyon Auxiliary Safeguards Cabinets

    International Nuclear Information System (INIS)

    Riggio, M.D.; Jarecki, S.J.

    1977-10-01

    This report presents the results of the analysis performed for the seismic qualification of the rotary relay for use in the Trojan and Diablo Canyon Auxiliary Safeguards Cabinets. A finite element model of the cabinet was developed from seismic test results. This model was analytically subjected to a simulated 3D floor acceleration time history that enveloped, simultaneously, the Trojan and the June 1969 Diablo Canyon Safe Shutdown Earthquake requirements. The dynamic response of the cabinet at the mounting location of the rotary relays was determined. The calculated acceleration time histories were converted to response spectra and these response spectra were compared to the test response spectra successfully achieved during the rotary relay seismic qualification tests. It was found that the dynamic motion levels at the rotary relays, when mounted in the Trojan or Diablo Canyon Auxiliary Safeguards Cabinets, do not exceed the levels for which they were previously seismically qualified by tests. Consequently, the rotary relays are seismically qualified for use in the Trojan or Diablo Canyon Auxiliary Safeguards Cabinets

  14. History of Snake River Canyon Indicated by Revised Stratigraphy of Snake River Group Near Hagerman and King Hill, Idaho: With a Section on Paleomagnetism

    Science.gov (United States)

    Malde, Harold E.; Cox, Allan

    1971-01-01

    A discovery that debris left by the Bonneville Flood (Melon Gravel) overlies McKinney Basalt about 200 feet above the Snake River near King Hill requires that the stratigraphy of the Snake River Group be revised. In former usage, the McKinney Basalt and its immediately older companion, the Wendell Grade Basalt, were considered on the basis of equivocal field relations to be younger than the Melon Gravel and were assigned to the Recent. These lava flows are here reclassified as Pleistocene. The Bancroft Springs Basalt, which consists of both subaerial lava and pillow lava in a former Snake River canyon, was previously separated from the McKinney but is now combined with the McKinney. Accordingly, the name Bancroft Springs Basalt is here abandoned. This revised stratigraphy is first described from geomorphic relations of the McKinney Basalt near King Hill and is then discussed in the light of drainage changes caused by local lava flows during entrenchment of the Snake River. Near King Hill, a former Snake River canyon was completely filled by McKinney Basalt at the place called Bancroft Springs, hut the depth of this lava in the next several miles of the canyon downstream (along a route that approximately coincides with the present canyon) steadily decreased. This ancestral geomorphology is inferred from the former canyon route and, also, from the continuity in gradient of the McKinney lava surface downstream from Bancroft Springs. The drainage history recorded by various lava flows and river deposits of the Snake River Group indicates that the McKinney and Wendell Grade Basalts erupted after the Snake River canyon had reached its present depth of about 500 feet. The Snake River of that time, as far downstream as Bliss, flowed approximately along its present route. The Wood River of that time, however, skirted the north flank of Gooding Butte and joined the ancestral Snake at a junction, now concealed by lava, north of the present canyon about 3 miles west of Bliss

  15. Deep-Sea, Deep-Sequencing: Metabarcoding Extracellular DNA from Sediments of Marine Canyons.

    Directory of Open Access Journals (Sweden)

    Magdalena Guardiola

    Full Text Available Marine sediments are home to one of the richest species pools on Earth, but logistics and a dearth of taxonomic work-force hinders the knowledge of their biodiversity. We characterized α- and β-diversity of deep-sea assemblages from submarine canyons in the western Mediterranean using an environmental DNA metabarcoding. We used a new primer set targeting a short eukaryotic 18S sequence (ca. 110 bp. We applied a protocol designed to obtain extractions enriched in extracellular DNA from replicated sediment corers. With this strategy we captured information from DNA (local or deposited from the water column that persists adsorbed to inorganic particles and buffered short-term spatial and temporal heterogeneity. We analysed replicated samples from 20 localities including 2 deep-sea canyons, 1 shallower canal, and two open slopes (depth range 100-2,250 m. We identified 1,629 MOTUs, among which the dominant groups were Metazoa (with representatives of 19 phyla, Alveolata, Stramenopiles, and Rhizaria. There was a marked small-scale heterogeneity as shown by differences in replicates within corers and within localities. The spatial variability between canyons was significant, as was the depth component in one of the canyons where it was tested. Likewise, the composition of the first layer (1 cm of sediment was significantly different from deeper layers. We found that qualitative (presence-absence and quantitative (relative number of reads data showed consistent trends of differentiation between samples and geographic areas. The subset of exclusively benthic MOTUs showed similar patterns of β-diversity and community structure as the whole dataset. Separate analyses of the main metazoan phyla (in number of MOTUs showed some differences in distribution attributable to different lifestyles. Our results highlight the differentiation that can be found even between geographically close assemblages, and sets the ground for future monitoring and conservation

  16. SCIENCE AND TECHNOLOGY PARKS

    Directory of Open Access Journals (Sweden)

    Miroslav Milutinović

    2014-04-01

    Full Text Available The establishment of science and technology parks is necessarily accompanied by the establishment of a base of professional staff as the foundation of the park and the base of the potential management that will manage the park and the professional staff. Science and Technology Park is a broader term used to describe a variety of attempts directed at enhancing the entrepreneurship development by means of establishing knowledge – based, small and medium-sized enterprises. The enterprise at the top of the technology pyramid receives support in the form of capital, administration, space and access to new information technologies. The overall objective of the development of industrial enterprises in the technology park is the introduction of economically profitable production with the efficient usage of nonrenewable resources and the application of the highest environmental standards. Achieving the primary developmental objective of the Technology Park includes: creating a favorable business atmosphere in the local community, attractive to both foreign and domestic investors – providing support to the establishment of small and medium-sized enterprises using different models of joint ventures and direct foreign investment.

  17. Late Holocene sea ice conditions in Herald Canyon, Chukchi Sea

    Science.gov (United States)

    Pearce, C.; O'Regan, M.; Rattray, J. E.; Hutchinson, D. K.; Cronin, T. M.; Gemery, L.; Barrientos, N.; Coxall, H.; Smittenberg, R.; Semiletov, I. P.; Jakobsson, M.

    2017-12-01

    Sea ice in the Arctic Ocean has been in steady decline in recent decades and, based on satellite data, the retreat is most pronounced in the Chukchi and Beaufort seas. Historical observations suggest that the recent changes were unprecedented during the last 150 years, but for a longer time perspective, we rely on the geological record. For this study, we analyzed sediment samples from two piston cores from Herald Canyon in the Chukchi Sea, collected during the 2014 SWERUS-C3 Arctic Ocean Expedition. The Herald Canyon is a local depression across the Chukchi Shelf, and acts as one of the main pathways for Pacific Water to the Arctic Ocean after entering through the narrow and shallow Bering Strait. The study site lies at the modern-day seasonal sea ice minimum edge, and is thus an ideal location for the reconstruction of past sea ice variability. Both sediment cores contain late Holocene deposits characterized by high sediment accumulation rates (100-300 cm/kyr). Core 2-PC1 from the shallow canyon flank (57 m water depth) is 8 meter long and extends back to 4200 cal yrs BP, while the upper 3 meters of Core 4-PC1 from the central canyon (120 mwd) cover the last 3000 years. The chronologies of the cores are based on radiocarbon dates and the 3.6 ka Aniakchak CFE II tephra, which is used as an absolute age marker to calculate the marine radiocarbon reservoir age. Analysis of biomarkers for sea ice and surface water productivity indicate stable sea ice conditions throughout the entire late Holocene, ending with an abrupt increase of phytoplankton sterols in the very top of both sediment sequences. The shift is accompanied by a sudden increase in coarse sediments (> 125 µm) and a minor change in δ13Corg. We interpret this transition in the top sediments as a community turnover in primary producers from sea ice to open water biota. Most importantly, our results indicate that the ongoing rapid ice retreat in the Chukchi Sea of recent decades was unprecedented during the

  18. Smart parking management system with decal electronics system

    KAUST Repository

    Hussain, Muhammad Mustafa; Wicaksono, Irmandy

    2017-01-01

    Various examples are related to parking management, including identifying and reserving empty parking spaces. In one example, a smart parking space system includes a parking controller located at a parking space. The parking controller can identify a vehicle located at the parking space via an input sensor or a transceiver that initiates wireless communication with an electronic tag associated with the vehicle; and communicate a parking vacancy associated with the parking space to a remote computing device based at least in part on the identification of the vehicle. In another example, a computing device can receive parking vacancy data associated with a parking space from a parking controller; determine a parking vacancy associated with the parking space using the parking vacancy data; and encode for display on a client device a network page that includes an indication of the parking vacancy associated with the parking space.

  19. Smart parking management system with decal electronics system

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-09-21

    Various examples are related to parking management, including identifying and reserving empty parking spaces. In one example, a smart parking space system includes a parking controller located at a parking space. The parking controller can identify a vehicle located at the parking space via an input sensor or a transceiver that initiates wireless communication with an electronic tag associated with the vehicle; and communicate a parking vacancy associated with the parking space to a remote computing device based at least in part on the identification of the vehicle. In another example, a computing device can receive parking vacancy data associated with a parking space from a parking controller; determine a parking vacancy associated with the parking space using the parking vacancy data; and encode for display on a client device a network page that includes an indication of the parking vacancy associated with the parking space.

  20. The Role of Source Material in Basin Sedimentation, as Illustrated within Eureka Valley, Death Valley National Park, CA.

    Science.gov (United States)

    Lawson, M. J.; Yin, A.; Rhodes, E. J.

    2015-12-01

    Steep landscapes are known to provide sediment to sink regions, but often petrological factors can dominate basin sedimentation. Within Eureka Valley, in northwestern Death Valley National Park, normal faulting has exposed a steep cliff face on the western margin of the Last Chance range with four kilometers of vertical relief from the valley floor and an angle of repose of nearly 38 degrees. The cliff face is composed of Cambrian limestone and dolomite, including the Bonanza King, Carrara and Wood Canyon formations. Interacting with local normal faulting, these units preferentially break off the cliff face in coherent blocks, which result in landslide deposits rather than as finer grained material found within the basin. The valley is well known for a large sand dune, which derives its sediment from distal sources to the north, instead of from the adjacent Last Chance Range cliff face. During the Holocene, sediment is sourced primary from the northerly Willow Wash and Cucomungo canyon, a relatively small drainage (less than 80 km2) within the Sylvan Mountains. Within this drainage, the Jurassic quartz monzonite of Beer Creek is heavily fractured due to motion of the Fish Valley Lake - Death Valley fault zone. Thus, the quartz monzonite is more easily eroded than the well-consolidated limestone and dolomite that forms the Last Change Range cliff face. As well, the resultant eroded material is smaller grained, and thus more easily transported than the limestone. Consequently, this work highlights an excellent example of the strong influence that source material can have on basin sedimentation.

  1. 78 FR 79436 - Boulder Canyon Project-Post-2017 Resource Pool

    Science.gov (United States)

    2013-12-30

    ... customers of electric utilities. The marketing criteria should include municipal corporations and political... Pool AGENCY: Western Area Power Administration, DOE. ACTION: Notice of final marketing criteria and... marketing agency of the Department of Energy (DOE), announces the Boulder Canyon Project (BCP) post-2017...

  2. A Computational Fluid Dynamic (CFD) Simulation of PM10 Dispersion Caused by Rail Transit Construction Activity: A Real Urban Street Canyon Model

    Science.gov (United States)

    Wang, Yang; Zhou, Ying; Zuo, Jian

    2018-01-01

    Particle emissions derived from construction activities have a significant impact on the local air quality, while the canyon effect with reduced natural ventilation contributes to the highest particulate pollution in urban environments. This study attempted to examine the effect of PM10 emissions derived from the construction of a rail transit system in an urban street canyon. Using a 3D computational fluid dynamic (CFD) model based on a real street canyon with different height ratios, this study formulates the impact of height ratio and wind directions on the dispersion and concentration of PM10. The results indicate that parallel flow would cause the concentration of PM10 at the end of the street canyons in all height ratios, and the trends in horizontal, vertical and lateral planes in all street canyons are similar. While in the condition of perpendicular flow, double-eddy circulations occur and lead to the concentration of PM10 in the middle part of the street canyon and leeward of backwind buildings in all height ratios. Furthermore, perpendicular flow will cause the concentration of PM10 to increase if the upwind buildings are higher than the backwind ones. This study also shows that the dispersion of PM10 is strongly associated with wind direction in and the height ratios of the street canyons. Certain measures could, therefore, be taken to prevent the impact on people in terms of the PM10 concentration and the heights of street canyons identified in this research. Potential mitigation strategies are suggested, include measurements below 4 m according to governmental regulations, dust shields, and atomized water. PMID:29522495

  3. A Computational Fluid Dynamic (CFD) Simulation of PM10 Dispersion Caused by Rail Transit Construction Activity: A Real Urban Street Canyon Model.

    Science.gov (United States)

    Wang, Yang; Zhou, Ying; Zuo, Jian; Rameezdeen, Raufdeen

    2018-03-09

    Particle emissions derived from construction activities have a significant impact on the local air quality, while the canyon effect with reduced natural ventilation contributes to the highest particulate pollution in urban environments. This study attempted to examine the effect of PM 10 emissions derived from the construction of a rail transit system in an urban street canyon. Using a 3D computational fluid dynamic (CFD) model based on a real street canyon with different height ratios, this study formulates the impact of height ratio and wind directions on the dispersion and concentration of PM 10 . The results indicate that parallel flow would cause the concentration of PM 10 at the end of the street canyons in all height ratios, and the trends in horizontal, vertical and lateral planes in all street canyons are similar. While in the condition of perpendicular flow, double-eddy circulations occur and lead to the concentration of PM 10 in the middle part of the street canyon and leeward of backwind buildings in all height ratios. Furthermore, perpendicular flow will cause the concentration of PM 10 to increase if the upwind buildings are higher than the backwind ones. This study also shows that the dispersion of PM 10 is strongly associated with wind direction in and the height ratios of the street canyons. Certain measures could, therefore, be taken to prevent the impact on people in terms of the PM 10 concentration and the heights of street canyons identified in this research. Potential mitigation strategies are suggested, include measurements below 4 m according to governmental regulations, dust shields, and atomized water.

  4. A Computational Fluid Dynamic (CFD Simulation of PM10 Dispersion Caused by Rail Transit Construction Activity: A Real Urban Street Canyon Model

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2018-03-01

    Full Text Available Particle emissions derived from construction activities have a significant impact on the local air quality, while the canyon effect with reduced natural ventilation contributes to the highest particulate pollution in urban environments. This study attempted to examine the effect of PM10 emissions derived from the construction of a rail transit system in an urban street canyon. Using a 3D computational fluid dynamic (CFD model based on a real street canyon with different height ratios, this study formulates the impact of height ratio and wind directions on the dispersion and concentration of PM10. The results indicate that parallel flow would cause the concentration of PM10 at the end of the street canyons in all height ratios, and the trends in horizontal, vertical and lateral planes in all street canyons are similar. While in the condition of perpendicular flow, double-eddy circulations occur and lead to the concentration of PM10 in the middle part of the street canyon and leeward of backwind buildings in all height ratios. Furthermore, perpendicular flow will cause the concentration of PM10 to increase if the upwind buildings are higher than the backwind ones. This study also shows that the dispersion of PM10 is strongly associated with wind direction in and the height ratios of the street canyons. Certain measures could, therefore, be taken to prevent the impact on people in terms of the PM10 concentration and the heights of street canyons identified in this research. Potential mitigation strategies are suggested, include measurements below 4 m according to governmental regulations, dust shields, and atomized water.

  5. Comparative study of measured and modelled number concentrations of nanoparticles in an urban street canyon

    DEFF Research Database (Denmark)

    Kumar, Prashant; Garmory, Andrew; Ketzel, Matthias

    2009-01-01

    Pollution Model (OSPM) and Computational Fluid Dynamics (CFD) code FLUENT. All models disregarded any particle dynamics. CFD simulations have been carried out in a simplified geometry of the selected street canyon. Four different sizes of emission sources have been used in the CFD simulations to assess......This study presents a comparison between measured and modelled particle number concentrations (PNCs) in the 10-300 nm size range at different heights in a canyon. The PNCs were modelled using a simple modelling approach (modified Box model, including vertical variation), an Operational Street...... the effect of source size on mean PNC distributions in the street canyon. The measured PNCs were between a factor of two and three of those from the three models, suggesting that if the model inputs are chosen carefully, even a simplified approach can predict the PNCs as well as more complex models. CFD...

  6. Understanding parking habits at CERN

    CERN Multimedia

    Anaïs Schaeffer

    2016-01-01

    The SMB department is setting up a monitoring system in certain CERN car parks in order to evaluate their occupancy rates and subsequently make them easier to use.    Vehicle registration plate readers (red triangles) are now installed at the entrances and exits of the Le Cèdres car park (in orange) and of the Building 4 and 5 one (in blue). The 2 other car parks (Building 40 in violet and “high-voltage” in green) will be equipped at a later stage. Vehicle registration plate readers are now installed at the entrances and exits of the Les Cèdres car park and of the Building 4 and 5 car park, both on the Meyrin site. The information collected by these readers will allow the occupancy levels of these car parks to be analysed throughout the day, establishing periods of peak usage and the pattern of vehicle movements. “We have been experiencing parking problems at CERN for several years n...

  7. Ensonifying Change: Repeat Ultra-High-Resolution Surveys in Monterey Canyon before and after Passage of a Turbidity Current

    Science.gov (United States)

    Wolfson-Schwehr, M.; Paull, C. K.; Caress, D. W.; Carvajal, C.; Thomas, H. J.; Maier, K. L.; Parsons, D. R.; Simmons, S.

    2017-12-01

    Turbidity currents are one of the primary means of global sediment transport, yet our understanding of how they interact with the seafloor is hindered by the limited number of direct measurements. The Coordinated Canyon Experiment (CCE; October 2015 - April 2017) has made great strides in addressing this issue by providing direct measurements of turbidity currents and detailed observations of the resulting seafloor change in Monterey Canyon, offshore California. Here we focus on a section of the canyon at 1850-m water depth, where a Seafloor Instrument Node (SIN) recorded passage of three turbidity currents using a range of sensors, including three upward-looking acoustic Doppler current profilers. The fastest event at this site had a maximum velocity of 2.8 m/s, and dragged the 430-Kg SIN 26 m down-canyon. Repeat mapping surveys were conducted four times during the CCE, utilizing a prototype ultra-high-resolution mapping system mounted on the ROV Doc Ricketts. The survey platform hosts a 400-kHz Reson 7125 multibeam sonar, a 3DatDepth SL1 subsea LiDAR, two stereo color cameras, and a Kearfott SeaDevil INS. At a survey altitude of 2.5 m above the bed, the system provides remarkable 5-cm resolution multibeam bathymetry, 1-cm resolution LiDAR bathymetry, and 2-mm resolution photomosaics, and can cover a 100-m2 survey area. Surveys of the SIN site prior to and after the fastest event show areas of net deposition/erosion of 60 cm and 20 cm, respectively. Net deposition occurred in the topographic lows between bedforms, while erosion was focused on the bedform crests. At the end of the experiment, transects of sediment cores were taken by ROV within areas of net deposition. The cores show a variety of sedimentary facies, including muds, sands, gravel, and organic rich layers. Gravel layers have sharp erosive bases. The repeat surveys document the dynamic nature of flute-like scours as the flow events erode and deposit material along the canyon floor, as well as the

  8. LES of flow in the street canyon

    Science.gov (United States)

    Fuka, Vladimír; Brechler, Josef

    2012-04-01

    Results of computer simulation of flow over a series of street canyons are presented in this paper. The setup is adapted from an experimental study by [4] with two different shapes of buildings. The problem is simulated by an LES model CLMM (Charles University Large Eddy Microscale Model) and results are analysed using proper orthogonal decomposition and spectral analysis. The results in the channel (layout from the experiment) are compared with results with a free top boundary.

  9. The Open Space Sculptures Used in the Gençlik Park towards Visual Perception of Park Users

    Directory of Open Access Journals (Sweden)

    Ahmet Polat

    2012-11-01

    Full Text Available Urban parks are the most important areas that allow recreational activities in our towns. Increasing the visual quality of urban parks provides positive impacts on urban quality. Besides the artistic and technical features of open space sculptures which are used for urban park designs are the visual perceptions and preferences of park users are also important. In the context of this study, six sculptures in Gençlik Park which is in the boundaries Ankara have been considered. The aim of the study, to measure the visual quality of the sculptures in the urban parks through park users and to reveal the relationship between visual landscape indicators (of being interesting, coherence, complexity, meaningfulness, and mystery and the visual quality. For this purpose, the six pieces in Ankara Youth Park of sculpture were evaluated the scope of research. According to the results of the study; it was realized that park users like sculptures visually. A statistically significant relationship was found between the visual quality of the sculptures and some landscape indicators (to be interesting, mystery and harmony. In addition to these, some suggestions were made regarding the use of sculptures in urban parks.

  10. Seasonal to Mesoscale Variability of Water Masses in Barrow Canyon,Chukchi Sea

    Science.gov (United States)

    Nobre, C.; Pickart, R. S.; Moore, K.; Ashjian, C. J.; Arrigo, K. R.; Grebmeier, J. M.; Vagle, S.; Itoh, M.; Berchok, C.; Stabeno, P. J.; Kikuchi, T.; Cooper, L. W.; Hartwell, I.; He, J.

    2016-02-01

    Barrow Canyon is one of the primary conduits by which Pacific-origin water exits the Chukchi Sea into the Canada Basin. As such, it is an ideal location to monitor the different water masses through the year. At the same time, the canyon is an energetic environment where mixing and entrainment can occur, modifying the pacific-origin waters. As part of the Distributed Biological Observatory (DBO) program, a transect across the canyon was occupied 24 times between 2010-2013 by international ships of opportunity passing through the region during summer and early-fall. Here we present results from an analysis of these sections to determine the seasonal evolution of the water masses and to investigate the nature of the mesoscale variability. The mean state shows the clear presence of six water masses present at various times through the summer. The seasonal evolution of these summer water masses is characterized both in depth space and in temperature-salinity (T-S) space. Clear patterns emerge, including the arrival of Alaskan coastal water and its modification in early-fall. The primary mesoscale variability is associated with wind-driven upwelling events which occur predominantly in September. The atmospheric forcing of these events is investigated as is the oceanic response.

  11. A Survey of Intelligent Car Parking System

    OpenAIRE

    Faheem; S.A. Mahmud; G.M. Khan; M. Rahman; H. Zafar

    2013-01-01

    The industrialization of the world, increase in population, slow paced city development and mismanagement of the available parking space has resulted in parking related problems. There is a dire need for a secure, intelligent, efficient and reliable system which can be used for searching the unoccupied parking facility, guidance towards the parking facility, negotiation of the parking fee, along with the proper management of the parking facility. Intelligent Parking Service is a part of Intel...

  12. Generalizing ecological site concepts of the Colorado Plateau for landscape-level applications

    Science.gov (United States)

    The Colorado Plateau is an iconic landscape of the American West— containing dozens of national parks, monuments, historic sites, and several UNESCO World Heritage Sites— including some of the Nation’ s most recognizable landmarks, such as the Grand Canyon and the Arches National Park. The concentra...

  13. Parking Space Verification

    DEFF Research Database (Denmark)

    Høg Peter Jensen, Troels; Thomsen Schmidt, Helge; Dyremose Bodin, Niels

    2018-01-01

    system, based on a Convolutional Neural Network, that is capable of determining if a parking space is occupied or not. A benchmark database consisting of images captured from different parking areas, under different weather and illumination conditions, has been used to train and test the system...

  14. Impact of height and shape of building roof on air quality in urban street canyons

    Science.gov (United States)

    Yassin, Mohamed F.

    2011-09-01

    A building's roof shape and roof height play an important role in determining pollutant concentrations from vehicle emissions and its complex flow patterns within urban street canyons. The impact of the roof shape and height on wind flow and dispersion of gaseous pollutants from vehicle exhaust within urban canyons were investigated numerically using a Computational Fluid Dynamics (CFD) model. Two-dimensional flow and dispersion of gaseous pollutants were analyzed using standard κ- ɛ turbulence model, which was numerically solved based on Reynolds Averaged Navier-Stokes (RANS) equations. The diffusion fields in the urban canyons were examined with three roof heights ( Z H/ H = 0.17, 0.33 and 0.5) and five roof shapes: (1) flat-shaped roof, (2) slanted-shaped roof, (3) downwind wedge-shaped roof, (4) upwind wedge-shaped roof, and (5) trapezoid-shaped roof. The numerical model was validated against the wind tunnels results in order to optimize the turbulence model. The numerical simulations agreed reasonably with the wind tunnel results. The results obtained indicated that the pollutant concentration increased as the roof height decreases. It also decreased with the slanted and trapezoid-shaped roofs but increased with the flat-shaped roof. The pollutant concentration distributions simulated in the present work, indicated that the variability of the roof shapes and roof heights of the buildings are important factors for estimating air quality within urban canyons.

  15. Configuration study of large wind parks

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, Stefan

    2003-07-01

    In this thesis, layouts of various large-scale wind parks, using both AC as well as DC, are investigated. Loss modelling of the wind park components as well as calculations of the energy capture of the turbines using various electrical systems are performed, and the energy production cost of the various park configurations is determined. The most interesting candidate for a DC transmission based wind park was investigated more in detail, the series DC wind park. Finally, the power quality impact in the PCC (point of common coupling) was studied. It was found that from an energy capture point of view, the difference in energy production between various wind turbine systems is very small. Of all the investigated wind park configurations, the wind park with the series connected DC wind turbines seems to have the best potential to give the lowest energy production cost, if the transmission distance is longer then 10-20 km. Regarding the series DC wind park it was found that it is the most difficult one to control. However, a control algorithm for the series park and its turbines was derived and successfully tested. Still, several more details regarding the control of the series wind park has to be dealt with.

  16. SmartPark Technology Demonstration Project

    Science.gov (United States)

    2013-11-01

    The purpose of FMCSAs SmartPark initiative is to determine the feasibility of a technology for providing truck parking space availability in real time to truckers on the road. SmartPark consists of two phases. Phase I was a field operational test ...

  17. Sedimentary characteristics of samples collected from some submarine canyons

    NARCIS (Netherlands)

    Bouma, Arnold H.

    Oriented rectangular cores of 20.3 × 30.5 cm and 45.7 cm high have been collected in a number of submarine canyons off southern California (U.S.A.) and off the southern tip of Baja California (Mexico) for a detailed study of their sedimentary structures. By applying several methods, mainly X-ray

  18. Seasonal Changing Effect on Airflow and Pollutant Dispersion Characteristics in Urban Street Canyons

    Directory of Open Access Journals (Sweden)

    Jingliang Dong

    2017-02-01

    Full Text Available In this study, the effect of seasonal variation on air flow and pollutant dispersion characteristics was numerically investigated. A three-dimensional urban canopy model with unit aspect ratio (H/D = 1 was used to calculate surface temperature distribution in the street canyon. Four representative time events (1000 LST, 1300 LST, 1600 LST and 2000 LST during typical clear summer and winter days were selected to examine the air flow diurnal variation. The results revealed the seasonal variation significantly altered the street canyon microclimate. Compared with the street canyon surface temperature distribution in summer, the winter case showed a more evenly distributed surface temperature. In addition, the summer case showed greater daily temperature fluctuation than that of the winter case. Consequently, distinct pollutant dispersion patterns were observed between summer and winter scenarios, especially for the afternoon (1600 LST and night (2000 LST events. Among all studied time events, the pollutant removal performance of the morning (1000 LST and the night (2000 LST events were more sensitive to the seasonal variation. Lastly, limited natural ventilation performance was found during the summer morning and the winter night, which induced relatively high pollutant concentration along the pedestrian height level.

  19. Application of a Three-Layer Photochemical Box Model in an Athens Street Canyon.

    Science.gov (United States)

    Proyou, Athena G; Ziomas, Loannis C; Stathopoulos, Antony

    1998-05-01

    The aim of this paper is to show that a photochemical box model could describe the air pollution diurnal profiles within a typical street canyon in the city of Athens. As sophisticated three-dimensional dispersion models are computationally expensive and they cannot serve to simulate pollution levels in the scale of an urban street canyon, a suitably modified three-layer photochemical box model was applied. A street canyon of Athens with heavy traffic was chosen to apply the aforementioned model. The model was used to calculate pollutant concentrations during two days with meteorological conditions favoring pollutant accumulation. Road traffic emissions were calculated based on existing traffic load measurements. Meteorological data, as well as various pollutant concentrations, in order to compare with the model results, were provided by available measurements. The calculated concentrations were found to be in good agreement with measured concentration levels and show that, when traffic load and traffic composition data are available, this model can be used to predict pollution episodes. It is noteworthy that high concentrations persisted, even after additional traffic restriction measures were taken on the second day because of the high pollution levels.

  20. Parking regulations on the CERN sites

    CERN Multimedia

    General Infrastructure Services Department

    2010-01-01

    The site surveillance service is also responsible for supervising compliance with the parking regulations on the CERN site. In that context, it ensures that the following rules are complied with on the CERN car park: Vehicles may not be left on a CERN car park for longer than 5 consecutive working days. However, CERN users are entitled to leave their vehicles parked at CERN for a longer period in the car park near Building 588 , subject to completing the application form "Demande d'autorisation pour un stationnement de longue durée" (application for a long-term parking permit) and sending it to the Reception and Access Control Service (access.surveillance@cern.ch) prior to departure.   Parking spaces, which are in short supply in many crowded areas of the CERN site, must not be occupied by abandoned vehicles/wrecks. The service organizes the disposal of such vehicles. Any CERN users wishing to get rid of a private vehicle parked on one of the CERN car pa...

  1. Full-Automatic Parking registration and payment

    DEFF Research Database (Denmark)

    Agerholm, Niels; Lahrmann, Harry; Jørgensen, Brian

    2014-01-01

    As part of ITS Platform North Denmark, a full-automatic GNSS-based parking payment (PP) system was developed (PP app). On the basis of the parking position and parking time, the PP app can determine the price of parking and collect the amount from the car owner’s bank account. The driver...... is informed about any initiation of PP via SMS message. If the driver finds the payment erroneous, it can be cancelled via SMS message. Parking attendants can check if the car in question has an ongoing payment for parking. To handle the problems with GNSS-based positioning in densely built-up areas......, an advanced map matching algorithm was integrated in the PP app. 24 of the participating vehicles used the PP app, and 58 parking payments were carried out without errors. In a few cases, the wrong parking area was selected. This was due to lack of information in the map rather than errors in the map matching...

  2. Time-series analysis to study the impact of an intersection on dispersion along a street canyon.

    Science.gov (United States)

    Richmond-Bryant, Jennifer; Eisner, Alfred D; Hahn, Intaek; Fortune, Christopher R; Drake-Richman, Zora E; Brixey, Laurie A; Talih, M; Wiener, Russell W; Ellenson, William D

    2009-12-01

    This paper presents data analysis from the Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) study to assess the transport of ultrafine particulate matter (PM) across urban intersections. Experiments were performed in a street canyon perpendicular to a highway in Brooklyn, NY, USA. Real-time ultrafine PM samplers were positioned on either side of an intersection at multiple locations along a street to collect time-series number concentration data. Meteorology equipment was positioned within the street canyon and at an upstream background site to measure wind speed and direction. Time-series analysis was performed on the PM data to compute a transport velocity along the direction of the street for the cases where background winds were parallel and perpendicular to the street. The data were analyzed for sampler pairs located (1) on opposite sides of the intersection and (2) on the same block. The time-series analysis demonstrated along-street transport, including across the intersection when background winds were parallel to the street canyon and there was minimal transport and no communication across the intersection when background winds were perpendicular to the street canyon. Low but significant values of the cross-correlation function (CCF) underscore the turbulent nature of plume transport along the street canyon. The low correlations suggest that flow switching around corners or traffic-induced turbulence at the intersection may have aided dilution of the PM plume from the highway. This observation supports similar findings in the literature. Furthermore, the time-series analysis methodology applied in this study is introduced as a technique for studying spatiotemporal variation in the urban microscale environment.

  3. Microbial Communities in Sunken Wood Are Structured by Wood-Boring Bivalves and Location in a Submarine Canyon

    Science.gov (United States)

    Fagervold, Sonja K.; Romano, Chiara; Kalenitchenko, Dimitri; Borowski, Christian; Nunes-Jorge, Amandine; Martin, Daniel; Galand, Pierre E.

    2014-01-01

    The cornerstones of sunken wood ecosystems are microorganisms involved in cellulose degradation. These can either be free-living microorganisms in the wood matrix or symbiotic bacteria associated with wood-boring bivalves such as emblematic species of Xylophaga, the most common deep-sea woodborer. Here we use experimentally submerged pine wood, placed in and outside the Mediterranean submarine Blanes Canyon, to compare the microbial communities on the wood, in fecal pellets of Xylophaga spp. and associated with the gills of these animals. Analyses based on tag pyrosequencing of the 16S rRNA bacterial gene showed that sunken wood contained three distinct microbial communities. Wood and pellet communities were different from each other suggesting that Xylophaga spp. create new microbial niches by excreting fecal pellets into their burrows. In turn, gills of Xylophaga spp. contain potential bacterial symbionts, as illustrated by the presence of sequences closely related to symbiotic bacteria found in other wood eating marine invertebrates. Finally, we found that sunken wood communities inside the canyon were different and more diverse than the ones outside the canyon. This finding extends to the microbial world the view that submarine canyons are sites of diverse marine life. PMID:24805961

  4. 77 FR 9265 - Glen Canyon Dam Adaptive Management Work Group

    Science.gov (United States)

    2012-02-16

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Glen Canyon Dam Adaptive Management Work Group... Adaptive Management Work Group (AMWG) makes recommendations to the Secretary of the Interior concerning.... L. 102-575) of 1992. The AMP includes a Federal advisory committee, the AMWG, a technical work group...

  5. Performance assessment of Large Eddy Simulation (LES) for modeling dispersion in an urban street canyon with tree planting

    Science.gov (United States)

    Moonen, P.; Gromke, C.; Dorer, V.

    2013-08-01

    The potential of a Large Eddy Simulation (LES) model to reliably predict near-field pollutant dispersion is assessed. To that extent, detailed time-resolved numerical simulations of coupled flow and dispersion are conducted for a street canyon with tree planting. Different crown porosities are considered. The model performance is assessed in several steps, ranging from a qualitative comparison to measured concentrations, over statistical data analysis by means of scatter plots and box plots, up to the calculation of objective validation metrics. The extensive validation effort highlights and quantifies notable features and shortcomings of the model, which would otherwise remain unnoticed. The model performance is found to be spatially non-uniform. Closer agreement with measurement data is achieved near the canyon ends than for the central part of the canyon, and typical model acceptance criteria are satisfied more easily for the leeward than for the windward canyon wall. This demonstrates the need for rigorous model evaluation. Only quality-assured models can be used with confidence to support assessment, planning and implementation of pollutant mitigation strategies.

  6. Sorting of Terrestrial and Marine Organic Matter along a Marginal Submarine Canyon: Radiocarbon and Biomarker Signatures of Surface Sediments

    Science.gov (United States)

    Close, H. G.; Doherty, S.; Campbell, P.; McCarthy, M. D.; Prouty, N.

    2016-02-01

    Submarine canyons are incised features of many continental margins that can have significant influence on the hydrodynamic distribution of sediments and organic matter (OM) eroded and deposited from the continents. Baltimore Canyon, on the U.S. mid-Atlantic margin, contains a complex set of sedimentary processes that simultaneously create unique benthic habitats and control the deposition of OM. Along the canyon axis, loci of net erosion, net deposition, and intense winnowing each host diverse faunal assemblages and varying mixtures of sedimentary OM derived both from production in the overlying water column and from mobilized sediments. Bioavailable components of this deposited OM sustain benthic communities, while recalcitrant components can contribute to long-term carbon burial in the deep sea. Here we probe in detail the terrestrial versus marine origins of OM along a transect of Baltimore Canyon, as well as its bioavailability for benthic fauna, in order to explore how canyon-specific sediment dynamics might emplace a functional sorting of OM from shelf to open ocean. Determining the provenance of sedimentary OM is a continual challenge: commonly-measured bulk geochemical properties often provide insufficient information to distinguish end-member sources. We present a novel approach to separate functional classes of OM and investigate sources and degradative pathways of OM in Baltimore Canyon. In combination with bulk geochemical characteristics, surface sediments from water depths of 200-1200 meters were sequentially extracted (solvent-extracted, acid-hydrolyzed, and demineralized) to separate pools containing different prevalence of terrigenous, marine, and recalcitrant OM. Each class was analyzed for biomarker distributions; amino acid content, 13C signatures, and degradation indicators; bulk carbon and nitrogen isotopes; and radiocarbon content in order to characterize potential end-member sources within the mixture, as well as their age profiles. These

  7. Decontamination of Savannah River Plant H-Area hot-canyon crane

    International Nuclear Information System (INIS)

    Rankin, W.N.; Sims, J.R.

    1985-01-01

    Decontamination techniques applicable to the remotely operated bridge cranes in canyon buildings at the Savannah River Plant (SRP) were identified and were evaluated in laboratory-scale tests. High pressure Freon blasting was found to be the most attractive process available for this application. Strippable coatings were selected as an alternative technique in selected applications. The ability of high pressure Freon blasting plus two strippable coatings (Quadcoat 100 and Alara 1146) to remove the type of contamination expected on SRP cranes was demonstrated in laboratory-scale tests. Quadrex HPS was given a contract to decontaminate the H-Area hot canyon crane. Decontamination operations were successfully carried out within the specified time-frame window. The radiation level goals specified by SRP were met and decontamination was accomplished with 85% less personnel exposure than estimated by SRP before the job started. This reduction is attributed to the increased efficiency of the new decontamination techniques used. 6 refs., 1 tab

  8. Metal assessment in urban park soils in Sao Paulo 1. Ibirapuera Park

    International Nuclear Information System (INIS)

    Figueiredo, Ana Maria G.; Camargo, Sonia P.; Pavese, Arthur C.; Gumiero, Felipe C.; Enzweiler, Jacinta; Sigolo, Joel B.

    2007-01-01

    In the last years urban soils received increasing attention by scientists, leading to studies focused on their description and investigation all over the world, due to the increasing metal pollution derived from incinerators, industrial waste, atmospheric deposition of dust and aerosols, and other activities. Metal contamination in Sao Paulo public parks is an important environmental question and there is little information on this subject. As part of a project which aims metal assessment in urban park soils from Sao Paulo, in the present paper the concentration of the elements As, Ba, Cr, Pb, Sb and Zn were determined in surface soil samples (0-5 cm) from Ibirapuera park of Sao Paulo. Ibirapuera park is one of the biggest and most visited parks of the city of Sao Paulo, receiving during the weekends more than 400,000 visitors. Instrumental Neutron Activation Analysis (INAA) and X-ray Fluorescence (FRX) were used for metal analysis. Preliminary results showed concentration levels of the analyzed elements higher than the values considered as reference values for soils in Sao Paulo, according to the Environmental Protection Agency of the State of Sao Paulo (CETESB). For As, Ba, Cr and Sb, in some samples the concentrations were even higher than the Prevention values reported by CETESB. The high concentrations of the elements As, Ba, Cr, Pb, Sb and Zn in the Ibirapuera park top soils suggest an anthropogenic source and indicate a potential damage to soil quality. (author)

  9. Changing perspectives in urban park management

    DEFF Research Database (Denmark)

    Chan, Chung-shing; Marafa, Lawal M.; Konijnendijk, Cecil Cornelis

    2015-01-01

    managers in Hong Kong have encountered different challenges over time, and the quest for changing park managerial strategies. In 2004, a set of indicators for urban park management in Hong Kong was produced as part of a Master's research. Local park managers were asked about their views on the respective......Urban parks provide numerous benefits to our society. In densely populated metropolises such as Hong Kong, urban parks are in high demand. A variety of indicators can be used as tools for improving park planning and management. Facing a dynamic society and increasing user expectations, urban park...... importance and performance (I–P) of the indicators. In 2012, a follow-up questionnaire survey was conducted with the managers to study if their views regarding these indicators and their performance had changed. Results from the 2004 and 2012 surveys revealed changing perceptions regarding both I...

  10. Food-web dynamics and isotopic niches in deep-sea communities residing in a submarine canyon and on the adjacent open slopes

    NARCIS (Netherlands)

    Demopoulos, A.W.J.; McClain-Counts, J.; Ross, S.W.; Brooke, S.; Mienis, F.

    2017-01-01

    Examination of food webs and trophic niches provide insights into organisms’ functionalecology, yet few studies have examined trophodynamics within submarine canyons, wherethe interaction of canyon morphology and oceanography influences habitat provision and fooddeposition. Using stable isotope

  11. Parks of Chapel Hill

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Hours, location, and amenity information for Chapel Hill parks as shown on the Town of Chapel Hill's website. Includes a map with points for each park location.

  12. Newly recognized turbidity current structure can explain prolonged flushing of submarine canyons.

    Science.gov (United States)

    Azpiroz-Zabala, Maria; Cartigny, Matthieu J B; Talling, Peter J; Parsons, Daniel R; Sumner, Esther J; Clare, Michael A; Simmons, Stephen M; Cooper, Cortis; Pope, Ed L

    2017-10-01

    Seabed-hugging flows called turbidity currents are the volumetrically most important process transporting sediment across our planet and form its largest sediment accumulations. We seek to understand the internal structure and behavior of turbidity currents by reanalyzing the most detailed direct measurements yet of velocities and densities within oceanic turbidity currents, obtained from weeklong flows in the Congo Canyon. We provide a new model for turbidity current structure that can explain why these are far more prolonged than all previously monitored oceanic turbidity currents, which lasted for only hours or minutes at other locations. The observed Congo Canyon flows consist of a short-lived zone of fast and dense fluid at their front, which outruns the slower moving body of the flow. We propose that the sustained duration of these turbidity currents results from flow stretching and that this stretching is characteristic of mud-rich turbidity current systems. The lack of stretching in previously monitored flows is attributed to coarser sediment that settles out from the body more rapidly. These prolonged seafloor flows rival the discharge of the Congo River and carry ~2% of the terrestrial organic carbon buried globally in the oceans each year through a single submarine canyon. Thus, this new structure explains sustained flushing of globally important amounts of sediment, organic carbon, nutrients, and fresh water into the deep ocean.

  13. Growth and asymmetry of soil microfungal colonies from "Evolution Canyon," Lower Nahal Oren, Mount Carmel, Israel.

    Directory of Open Access Journals (Sweden)

    Shmuel Raz

    Full Text Available Fluctuating asymmetry is a contentious indicator of stress in populations of animals and plants. Nevertheless, it is a measure of developmental noise, typically obtained by measuring asymmetry across an individual organism's left-right axis of symmetry. These individual, signed asymmetries are symmetrically distributed around a mean of zero. Fluctuating asymmetry, however, has rarely been studied in microorganisms, and never in fungi.We examined colony growth and random phenotypic variation of five soil microfungal species isolated from the opposing slopes of "Evolution Canyon," Mount Carmel, Israel. This canyon provides an opportunity to study diverse taxa inhabiting a single microsite, under different kinds and intensities of abiotic and biotic stress. The south-facing "African" slope of "Evolution Canyon" is xeric, warm, and tropical. It is only 200 m, on average, from the north-facing "European" slope, which is mesic, cool, and temperate. Five fungal species inhabiting both the south-facing "African" slope, and the north-facing "European" slope of the canyon were grown under controlled laboratory conditions, where we measured the fluctuating radial asymmetry and sizes of their colonies.Different species displayed different amounts of radial asymmetry (and colony size. Moreover, there were highly significant slope by species interactions for size, and marginally significant ones for fluctuating asymmetry. There were no universal differences (i.e., across all species in radial asymmetry and colony size between strains from "African" and "European" slopes, but colonies of Clonostachys rosea from the "African" slope were more asymmetric than those from the "European" slope.Our study suggests that fluctuating radial asymmetry has potential as an indicator of random phenotypic variation and stress in soil microfungi. Interaction of slope and species for both growth rate and asymmetry of microfungi in a common environment is evidence of genetic

  14. 32 CFR 634.31 - Parking.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Parking. 634.31 Section 634.31 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.31 Parking. (a) The most efficient use of existing on- and off-street parking...

  15. Long-term surveillance plan for the Burro Canyon disposal cell Slick Rock, Colorado

    International Nuclear Information System (INIS)

    1997-08-01

    This long-term surveillance plan (LTSP) describes the U.S. Department of Energy's (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Burro Canyon disposal cell in San Miguel County, Colorado. This LSTP describes the long-term surveillance program the DOE will implement to ensure the Burro Canyon disposal cell performs as designed and is cared for in a manner that protects the public health and safety and the environment. The program is based on site inspections to identify threats to disposal cell integrity. Before each disposal cell is licensed for custody and long-term care, the Nuclear Regulatory Commission (NRC) requires the DOE to submit such a site-specific LTSP

  16. 75 FR 11169 - Reedsport OPT Wave Park Project; Reedsport OPT Wave Park; LLC Notice of Scoping Meetings and...

    Science.gov (United States)

    2010-03-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 12713-002] Reedsport OPT Wave Park Project; Reedsport OPT Wave Park; LLC Notice of Scoping Meetings and Environmental Site...: Reedsport OPT Wave Park, LLC. e. Name of Project: Reedsport OPT Wave Park Project. [[Page 11170

  17. Modeling In-Stream Hydro-Geomorphic Processes After 2012 Waldo Canyon Fire, Colorado

    Science.gov (United States)

    Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

    2016-12-01

    Wildfires can have significant impacts on hydrologic and geomorphic processes. Post-fire sediment transport and runoff generation vary by burn severity, precipitation, and vegetation. A need exists to understand these variable relationships and improve parameterization of post-fire hydro-geomorphic models. This research aims to model pre-fire geomorphic and hydrologic processes in Williams Canyon, a watershed burned by the 2012 Waldo Canyon Fire in Colorado. We develop the KINematic Runoff and EROSion (KINEROS) model with Geographical Information System (GIS)-based information, including a Digital Elevation Model, land cover, soil classification, precipitation, and soil burn severity for a local reference watershed that is unburned. We transfer these parameters to a channel reach in Williams Canyon (Williams Downstream) and adjust them toward post-fire conditions. We model runoff and sediment yield for several storms following the fire. Three post-fire terrestrial Light Detection and Ranging (LiDAR) images (21 April 2013, 14 September 2013, and 16 September 2014) are used to estimate total erosion and deposition at the reach scale. We use the LiDAR-based information to calibrate the post-fire model. Preliminary modeling results indicate 3870-125 kg/ha of sediment in the Williams Downstream reach. The uncalibrated model overestimated (410% in the first year) and underestimated (87.2% in the second year) the erosion. Model calibration reduced the Root Mean Square Error (RMSE) of sediment to 0.016% for the first year and 0.09% for the second year. The parameters calibrated for the Williams Downstream channel reach will be used to develop models for seven other channel reaches within the area burned by the Waldo Canyon Fire, where the performance can be evaluated with LiDAR estimates. Results of this research will enhance our understanding of wildfire disturbance on coupled hydrologic and geomorphic processes. Findings will also improve model parameterization that can

  18. Hydrogeology and sources of water to select springs in Black Canyon, south of Hoover Dam, Lake Mead National Recreation Area, Nevada and Arizona

    Science.gov (United States)

    Moran, Michael J.; Wilson, Jon W.; Beard, L. Sue

    2015-11-03

    Springs in Black Canyon of the Colorado River, directly south of Hoover Dam in the Lake Mead National Recreation Area, Nevada and Arizona, are important hydrologic features that support a unique riparian ecosystem including habitat for endangered species. Rapid population growth in areas near and surrounding Black Canyon has caused concern among resource managers that such growth could affect the discharge from these springs. The U.S. Geological Survey studied the springs in Black Canyon between January 2008, and May 2014. The purposes of this study were to provide a baseline of discharge and hydrochemical data from selected springs in Black Canyon and to better understand the sources of water to the springs.

  19. Turbulence and Air Exchange in a Two-Dimensional Urban Street Canyon Between Gable Roof Buildings

    Science.gov (United States)

    Garau, Michela; Badas, Maria Grazia; Ferrari, Simone; Seoni, Alessandro; Querzoli, Giorgio

    2018-04-01

    We experimentally investigate the effect of a typical building covering: the gable roof, on the flow and air exchange in urban canyons. In general, the morphology of the urban canopy is very varied and complex, depending on a large number of factors, such as building arrangement, or the morphology of the terrain. Therefore we focus on a simple, prototypal shape, the two-dimensional canyon, with the aim of elucidating some fundamental phenomena driving the street-canyon ventilation. Experiments are performed in a water channel, over an array of identical prismatic obstacles representing an idealized urban canopy. The aspect ratio, i.e. canyon-width to building-height ratio, ranges from 1 to 6. Gable roof buildings with 1:1 pitch are compared with flat roofed buildings. Velocity is measured using a particle-image-velocimetry technique with flow dynamics discussed in terms of mean flow and second- and third-order statistical moments of the velocity. The ventilation is interpreted by means of a simple well-mixed box model and the outflow rate and mean residence time are computed. Results show that gable roofs tend to delay the transition from the skimming-flow to the wake-interference regime and promote the development of a deeper and more turbulent roughness layer. The presence of a gable roof significantly increases the momentum flux, especially for high packing density. The air exchange is improved compared to the flat roof buildings, and the beneficial effect is more significant for narrow canyons. Accordingly, for unit aspect ratio gable roofs reduce the mean residence time by a factor of 0.37 compared to flat roofs, whereas the decrease is only by a factor of 0.9 at the largest aspect ratio. Data analysis indicates that, for flat roof buildings, the mean residence time increases by 30% when the aspect ratio is decreased from 6 to 2, whereas this parameter is only weakly dependent on aspect ratio in the case of gable roofs.

  20. Loss of residual heat removal system: Diablo Canyon, Unit 2, April 10, 1987

    International Nuclear Information System (INIS)

    1987-06-01

    This report presents the findings of an NRC Augmented Inspection Team (AIT) investigation into the circumstances associated with the loss of residual heat removal (RHR) system capability for a period of approximately one and one-half hours at the Diablo Canyon, Unit 2 reactor facility on April 10, 1987. This event occurred while the Diablo Canyon, Unit 2, a pressurized water reactor, was shutdown with the reactor coolant system (RCS) water level drained to approximately mid-level of the hot leg piping. The reactor containment building equipment hatch was removed at the time of the event, and plant personnel were in the process of removing the primary side manways to gain access into the steam generator channel head areas. Thus, two fission product barriers were breached throughout the event. The RCS temperature increased from approximately 87 0 F to bulk boiling conditions without RCS temperature indication available to the plant operators. The RCS was subsequently pressurized to approximately 7 to 10 psig. The NRC AIT members concluded that the Diablo Canyon, Unit 2 plant was, at the time of the event, in a condition not previously analyzed by the NRC staff. The AIT findings from this event appear significant and generic to other pressurized water reactor facilities licensed by the NRC