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Sample records for stream sediments stream

  1. Sedimentation in mountain streams: A review of methods of measurement

    Science.gov (United States)

    Hedrick, Lara B.; Anderson, James T.; Welsh, Stuart; Lin, Lian-Shin

    2013-01-01

    The goal of this review paper is to provide a list of methods and devices used to measure sediment accumulation in wadeable streams dominated by cobble and gravel substrate. Quantitative measures of stream sedimentation are useful to monitor and study anthropogenic impacts on stream biota, and stream sedimentation is measurable with multiple sampling methods. Evaluation of sedimentation can be made by measuring the concentration of suspended sediment, or turbidity, and by determining the amount of deposited sediment, or sedimentation on the streambed. Measurements of deposited sediments are more time consuming and labor intensive than measurements of suspended sediments. Traditional techniques for characterizing sediment composition in streams include core sampling, the shovel method, visual estimation along transects, and sediment traps. This paper provides a comprehensive review of methodology, devices that can be used, and techniques for processing and analyzing samples collected to aid researchers in choosing study design and equipment.

  2. Isolating the impact of sediment toxicity in urban streams

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Stephen, E-mail: s.marshall@zoology.unimelb.edu.a [Centre for Environmental Stress and Adaptation Research (CESAR), The University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, VIC 3010 (Australia); Pettigrove, Vincent [Melbourne Water Research and Technology, Melbourne Water Corporation, PO Box 4342, VIC 3000 (Australia); Carew, Melissa; Hoffmann, Ary [Centre for Environmental Stress and Adaptation Research (CESAR), The University of Melbourne, Bio21 Institute, 30 Flemington Road, Parkville, VIC 3010 (Australia)

    2010-05-15

    Several factors can contribute to the ecological degradation of stream catchments following urbanization, but it is often difficult to separate their relative importance. We isolated the impact of polluted sediment on the condition of an urban stream in Melbourne, Australia, using two complementary approaches. Using a rapid bioassessment approach, indices of stream condition were calculated based on macroinvertebrate field surveys. Urban stream reaches supported impoverished macroinvertebrate communities, and contained potentially toxic concentrations of heavy metals and hydrocarbons. Using a field microcosm approach, a bioassay was carried out to assess sediment pollution effects on native macroinvertebrates. Sediment from urban sites substantially altered the microcosm macroinvertebrate community, most likely due to elevated heavy metal and hydrocarbon concentrations. Macroinvertebrate surveys combined with a bioassay approach based on field microcosms can help isolate the effect of stream pollutants in degraded ecosystems. - Field microcosms isolate the ecological impact of polluted sediment in an urban stream.

  3. Monitoring changes in stream bottom sediments and benthic invertebrates.

    Science.gov (United States)

    1981-01-01

    The study was conducted to determine whether the analysis of stream bottom sediments could be used to assess sediment pollution generated by highway construction. Most of the work completed to date has involved testing and refining methods for the co...

  4. Sediment exchange between groin fields and main-stream

    Science.gov (United States)

    Qin, Jie; Zhong, Deyu; Wu, Teng; Wu, Lingli

    2017-10-01

    Sediment exchange between groin fields and the main-stream influences the transport and distribution of polluted sediment that represents a hazard for rivers and neighboring floodplains. Despite its practical significance, little research has been done on the sediment exchange process itself, and existing studies used to estimate the sediment exchange by morphological change. The sediment exchange process, however, differs from morphological variation and includes two behaviors: the entrance of main-stream sediment into groin fields and the movement of groin field sediment out of groin fields. Therefore, this study aims at examining this exchange process and exploring the mechanisms of different exchange phenomena. Experiments were conducted in a mobile-bed laboratory flume by using a novel experimental method that successfully separates the movement of groin fields sediment from that of main-stream sediment. In addition to traditional measurements, such as measurements of morphological changes, surface flow velocities, and bed-form propagation, the deposition of main-stream sediment in groin fields is measured in detail. The results demonstrate that morphological change cannot reflect the sediment exchange process. The deposition of main-stream sediment in groin fields is determined by the dynamics of sediment movement, in which bedload- and suspended-sediment-dominated processes exhibit different deposition patterns. The movement of groin field sediment out of groin fields is determined mainly by local scouring around groins.

  5. Heavy metal contamination in stream water and sediments of gold ...

    African Journals Online (AJOL)

    This study assessed the seasonal variation in heavy metal contamination of stream water and sediments in the gold mining area of Atakunmosa West local Government, Osun State, Nigeria. Twelve villages of prominence in illegal gold mining were selected for the study covering dry and wet seasons of 2012. Stream water ...

  6. Potential for 4-n-nonylphenol biodegradation in stream sediments

    Science.gov (United States)

    Bradley, P.M.; Barber, L.B.; Kolpin, D.W.; McMahon, P.B.; Chapelle, F.H.

    2008-01-01

    The potential for in situ biodegradation of 4-nonylphenol (4-NP) was investigated in three hydrologically distinct streams impacted by wastewater treatment plants (WWTPs) in the United States. Microcosms were prepared with sediments from each site and amended with [U-ring-14C]4-n-nonylphenol (4-n-NP) as a model test substrate. Microcosms prepared with sediment collected upstream of the WWTP outfalls and incubated under oxic conditions showed rapid and complete mineralization of [U-ring-14C]4- n-NP to 14CO2 in all three systems. In contrast, no mineralization of [U-ring-14C]4-n-NP was observed in these sediments under anoxic (methanogenic) conditions. The initial linear rate of [U-ring-14C]4-n-NP mineralization in sediments from upstream and downstream of the respective WWTP outfalls was inversely correlated with the biochemical oxygen demand (BOD) of the streambed sediments. These results suggest that the net supply of dissolved oxygen to streambed sediments is a key determinant of the rate and extent of 4-NP biodegradation in stream systems. In the stream systems considered by the present study, dissolved oxygen concentrations in the overlying water column (8–10 mg/L) and in the bed sediment pore water (1–3 mg/L at a depth of 10 cm below the sediment–water interface) were consistent with active in situ 4-NP biodegradation. These results suggest WWTP procedures that maximize the delivery of dissolved oxygen while minimizing the release of BOD to stream receptors favor efficient biodegradation of 4-NP contaminants in wastewater-impacted stream environments.

  7. Dynamic Hydraulic Conductivity, Streambed Sediment, and Biogeochemistry Following Stream Restoration

    Science.gov (United States)

    Baker, S.; Jefferson, A.; Kinsman-Costello, L. E.

    2015-12-01

    Stream restoration projects strive to improve water quality and degraded habitat, yet restoration projects often fall short of achieving their goals. Hyporheic exchange facilitates biogeochemical interaction which can contribute to positive water quality and habitat, but there are limited data on how restoration affects hyporheic processes. Hyporheic flowpaths can be altered by the processes and products of stream restoration, as well as the transport of fine sediment through the stream bed post-restoration. In two northeastern Ohio headwater streams, variations in hydraulic conductivity and pore water chemistry were monitored following restoration, as measures of hyporheic functioning. A second-order stream restored in August 2013, had a slight decrease in average hydraulic conductivity but an increase in heterogeneity from pre-restoration to four months post-restoration. Data collected 10 and 15 months post-restoration show continued declines in hydraulic conductivity throughout large constructed riffles. These piezometers also indicate dominance of downwelling throughout the riffles with only isolated upwelling locations. Grain size analysis of freeze cores collected in streambed sediments show differences suggesting fluvial transport and sorting have occurred since construction was completed. Pore water sampled from piezometers within the riffles had Mn2+ concentrations ten times higher than surface water, suggesting redox transformations are occurring along hyporheic flowpaths. A first-order stream reach, immediately downstream of a dam, restored in April 2014 had no significant change in average hydraulic conductivity between 1 and 2 months post-restoration, but many individual piezometers had increases of over 100% in high gradient positions or decreases of over 50% in low gradient positions. Changes in hydraulic conductivities in both restored streams are thought to be an adjustments from disturbance to a new dynamic equilibrium influenced by the morphology

  8. Uranium Hydrogeochemical and Stream Sediment Reconnaissance in southwestern Montana

    Energy Technology Data Exchange (ETDEWEB)

    Broxton, D.E.

    1978-02-01

    The Los Alamos Scientific Laboratory conducted a Hydrogeochemical and Stream Sediment Reconnaissance in southwestern Montana from early August to mid-October of 1976. A total of 1240 water and 1933 sediment samples were collected from 1994 locations at a nominal density of one location per 10 km/sup 2/. The water samples were collected from streams, wells, and springs; sediment samples were taken at streams and springs. All samples were analyzed at Los Alamos for total uranium by fluorometry or delayed-neutron counting. The uranium content of water samples ranges from below the detection limit (less than 0.3 ppB) to 45.30 ppB and has a mean value of 1.40 ppB. The uranium content of the sediment samples ranges between 0.20 and 206.80 ppM and averages 6.12 ppM. The chosen uranium anomaly threshold value was 7 ppB for surface waters (streams), 9 ppB for groundwaters (wells and springs), and 25 ppM for all sediment samples. The study area consists of the following lithologic groups: Precambrian basement complex, Precambrian Belt metasediments, Paleozoic and Mesozoic shelf sediments, Cretaceous and early Tertiary volcanic and plutonic rocks, Laramide orogenic clastic sediments, and middle to late Tertiary volcanic rocks and intermontane basin sediments. Most of the anomalous water and sediment samples with well-developed dispersion trains occur in areas underlain by or adjacent to silicic plutonic rocks of the Idaho and Boulder batholiths. These anomalies may indicate the presence of uraniferous veins and pegmatites similar to those already known to exist in the area. Fewer anomalous water samples occur in areas underlain by Precambrian basement complex and Tertiary basin fill.

  9. Ecoenzymatic Stoichiometry of Stream Sediments with Comparison to Terrestrial Soils

    Science.gov (United States)

    In this study, we extend the development of ecoenzymatic stoichiometry to the surface sediments of stream ecosystems using data collected in a nationwide survey. The data set is larger and more comprehensive than those used in our previous studies. The data include the first broa...

  10. Polycyclic Aromatic Hydrocarbons in Urban Stream Sediments

    Directory of Open Access Journals (Sweden)

    Jejal Reddy Bathi

    2012-01-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are persistent organic pollutants of high environmental concern with known carcinogenic activity. Although literature documents PAH fate in urban runoff, little is known about their distribution on sediment sizes, which is essential for determining their treatability and fate in receiving waters. This paper has quantified the concentrations of selected PAHs in urban creek sediments and examined possible relationships between sediment PAH content and sediment characteristics, such as particle size, volatile organic content (VOC, and sediment chemical oxygen demand (SCOD. SCOD, VOC, and PAH concentrations of sediments showed a bimodal distribution by particle size. The large diameter sediments had the highest VOC and also had the highest PAH concentrations. The spatial variation of PAH content by sediment sizes also was statistically significant; however, the mass of the PAH material was significantly affected by the relative abundance of the different particle size classes in the sediment mixtures.

  11. Effectiveness of best management practices for sediment reduction at operation forest stream crossings

    Science.gov (United States)

    Laura R. Wear; Michael W. Aust; M. Chad Bolding; Brian D. Strahm; C. Andrew. Dolloff

    2013-01-01

    Temporary skid trail stream crossings have repeatedly been identified as having considerable potential to introduce sediment to streams. Forestry Best Management Practices (BMPs) have proven to be effective for controlling erosion and subsequent sedimentation, yet few studies have quantified sedimentation associated with various levels of BMPs for skidder stream...

  12. Sediment fingerprinting to determine the source of suspended sediment in a southern Piedmont stream.

    Science.gov (United States)

    Mukundan, R; Radcliffe, D E; Ritchie, J C; Risse, L M; McKinley, R A

    2010-01-01

    Thousands of stream miles in the southern Piedmont region are impaired because of high levels of suspended sediment. It is unclear if the source is upland erosion from agricultural sources or bank erosion of historic sediment deposited in the flood plains between 1830 and 1930 when cotton farming was extensive. The objective of this study was to determine the source of high stream suspended sediment concentrations in a typical southern Piedmont watershed using sediment fingerprinting techniques. Twenty-one potential tracers were tested for their ability to discriminate between sources, conservative behavior, and lack of redundancy. Tracer concentrations were determined in potential sediment sources (forests, pastures, row crop fields, stream banks, and unpaved roads and construction sites), and suspended sediment samples collected from the stream and analyzed using mixing models. Results indicated that 137Cs and 15N were the best tracers to discriminate potential sediment sources in this watershed. The delta15N values showed distinct signatures in all the potential suspended sediment sources, and delta15N was a unique tracer to differentiate stream bank soil from upland subsurface soils, such as soil from construction sites, unpaved roads, ditches, and field gullies. Mixing models showed that about 60% of the stream suspended sediment originated from eroding stream banks, 23 to 30% from upland subsoil sources (e.g., construction sites and unpaved roads), and about 10 to 15% from pastures. The results may be applicable to other watersheds in the Piedmont depending on the extent of urbanization occurring in these watersheds. Better understanding of the sources of fine sediment has practical implications on the type of sediment control measures to be adopted. Investment of resources in improving water quality should consider the factors causing stream bank erosion and erosion from unpaved roads and construction sites to water quality impairment.

  13. Stream sediment detailed geochemical survey for Date Creek Basin, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Butz, T.R.; Tieman, D.J.; Grimes, J.G.; Bard, C.S.; Helgerson, R.N.; Pritz, P.M.

    1980-06-30

    Results of the Date Creek Basin detailed geochemical survey are reported. Field and laboratory data are reported for 239 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Based on stream sediment geochemical data, significant concentrations of uranium are restricted to the Anderson Mine area. The 84th percentile concentrations of U-FL, U-NT, and U-FL/U-NT combined with low thorium/U-NT values reflect increased mobility and enrichment of uranium in the carbonate host rocks of that area. Elements characteristically associated with the uranium mineralization include lithium and arsenic. No well defined diffusion halos suggesting outliers of similar uranium mineralization were observed from the stream sediment data in other areas of the Date Creek Basin. Significant concentrations of U-FL or U-NT found outside the mine area are generally coincident with low U-FL/U-NT values and high concentrations of zirconium, titanium, and phosphorus. This suggests that the uranium is related to a resistate mineral assemblage derived from surrounding crystalline igneous and metamorphic rocks.

  14. Forestry best management practices and sediment control at skidder stream crossings

    Science.gov (United States)

    Laura R. Wear; W. Michael Aust; M. Chad Bolding; Brian D. Strahm; Andrew C. Dolloff

    2015-01-01

    Stream crossings for skid trails have high sediment delivery ratios. Forestry Best Management Practices (BMPs) have proven to be effective for erosion control, but few studies have quantified the impact of various levels of BMPs on sedimentation. In this study, three skid-trail stream-crossing BMP treatments were installed on nine operational stream crossings (three...

  15. Natural radioactivity in stream sediments of Oltet River, Romania

    Science.gov (United States)

    Ion, Adriana

    2017-04-01

    The concentration of naturally occurring radionuclides (U-238, Th-232 and K-40) in stream sediments of the Oltet River was measured in order to establish the primary sources of radionuclides, the transport pathways and the geochemical factors favouring their mobilisation and concentration in the existing geological context. The Oltet River has a length of 185 Km and crosses the southern central part of the country, being the right tributary of the Olt River. The range in elevation of the watercourse varies between 1963 m in the springs area (Parîng Mountains) and 200 m at the confluence with the Olt River, whereas the relief of the Oltet Basin has a varied character, manifested by the presence of diverse forms of relief, starting with major mountainous heights and ending with low-lying plains regions. In cross section from North to South, the Olteț River cuts metamorphic rocks (schist, gneisses, quartzite, marble, mica-schist's), magmatic rocks (granite and granitoid massifs - intruded by veins of microgranite, aplite, pegmatite and lamprophyre) and limestone, followed by deposits composed of clays, marls, sands and gravels, that are characterized by the presence of lignite seams. 44 stream sediment samples were collected in summer of 2016 from sampling points distributed along the river with an equidistance of about 4 - 5 km. The activity concentrations of the U-238, Th-232 and K-40 were measured by gamma ray spectrometry using HPGe detector (ORTEC) with 26% relative efficiency in multilayer shielding. The reference materials used were IAEA - RGK-1 and IAEA - 314. Analysis was performed on the geochemical process the amounts of thorium and potassium released are modest, leaching of uranium being the dominant feature (uranyl ion). The downstream lignite seams are the secondary geochemical barriers in accumulation of uranium; the radiometric data obtained for stream sediments emphasize this enrichment.

  16. Effectiveness of forestry BMPS for stream crossing sediment reduction using rainfall simulation

    Science.gov (United States)

    Brian C. Morris; M. Chad Bolding; W. Michael Aust

    2015-01-01

    Recent decisions by the United States Supreme Court and United States Environmental Protection Agency (EPA) have re-emphasized the importance of forestry best management practices (BMPs) at stream crossings. Stream crossings are potential major sources of sediment due to their direct connectivity between the potential erosion source and the stream, which eliminates...

  17. Streams with Strahler Stream Order

    Data.gov (United States)

    Minnesota Department of Natural Resources — Stream segments with Strahler stream order values assigned. As of 01/08/08 the linework is from the DNR24K stream coverages and will not match the updated...

  18. Process recognition in multi-element soil and stream-sediment geochemical data

    Science.gov (United States)

    Grunsky, E.C.; Drew, L.J.; Sutphin, D.M.

    2009-01-01

    Stream-sediment and soil geochemical data from the Upper and Lower Coastal Plains of South Carolina (USA) were studied to determine relationships between soils and stream sediments. From multi-element associations, characteristic compositions were determined for both media. Primary associations of elements reflect mineralogy, including heavy minerals, carbonates and clays, and the effects of groundwater. The effects of groundwater on element concentrations are more evident in soils than stream sediments. A "winnowing index" was created using ratios of Th to Al that revealed differing erosional and depositional environments. Both soils and stream sediments from the Upper and Lower Coastal Plains show derivation from similar materials and subsequent similar multi-element relationships, but have some distinct differences. In the Lower Coastal Plain, soils have high values of elements concentrated in heavy minerals (Ce, Y, Th) that grade into high values of elements concentrated into finer-grain-size, lower-density materials, primarily comprised of carbonates and feldspar minerals (Mg, Ca, Na, K, Al). These gradational trends in mineralogy and geochemistry are inferred to reflect reworking of materials during marine transgressions and regressions. Upper Coastal Plain stream-sediment geochemistry shows a higher winnowing index relative to soil geochemistry. A comparison of the 4 media (Upper Coastal Plain soils and stream sediments and Lower Coastal Plain soils and stream sediments) shows that Upper Coastal Plain stream sediments have a higher winnowing index and a higher concentration of elements contained within heavy minerals, whereas Lower Coastal Plain stream sediments show a strong correlation between elements typically contained within clays. It is not possible to calculate a functional relationship between stream sediment-soil compositions for all elements due to the complex history of weathering, deposition, reworking and re-deposition. However, depending on

  19. Stream sediment geochemical survey of an area around Dass, N.E. ...

    African Journals Online (AJOL)

    Stream sediment geochemical survey was carried out in Dass area to determine possible dispersion train for Pb, Cu, Co, Ni and Zn. A total of 114 active stream sediment samples were collected over an area of 60km2. The samples were treated with hot HNO3 and analysed for Pb, Cu, Co, Ni, Zn, Mn, Mg, Ca, and Fe.

  20. Sediment motion and velocity in a glacier-fed stream

    Science.gov (United States)

    Mao, L.; Dell'Agnese, A.; Comiti, F.

    2017-08-01

    Current understanding of coarse sediment transport (e.g. threshold for motion, travel length and virtual velocity) in mountain rivers is still quite limited, and even less is known about glacial streams. However, the hydrological characteristics of these systems (strong daily discharge fluctuations, high water turbidity) pose challenges to the use of tracers to monitor bed sediment dynamics, as tagged clasts are usually located after bedload events when flow stage has receded, e.g. by means of portable antennas in the case of Passive Integrated Transponders (PIT). The use of stationary antennas, still scarcely in use worldwide, to detect PIT-tagged particles has potential advantages in glacier-fed streams. If water discharge is monitored continuously, a stationary antenna provides real time data on the actual discharge at the moment of tracer particles passage. This study focuses on incipient motion and virtual velocity of bed particles measured by a stationary antennas system in a steep mountain channel (Saldur River, drainage area 18.6 km2, Italian Alps) where significant daily discharge fluctuations and bedload transport occur as a result of a nivo-glacial regime. Four stationary antennas were installed 50-m apart in the study reach. A total of 629 PIT-tagged clasts were inserted in the studied reach between 2011 and 2014, ranging in size from 35 mm to 580 mm, with an overall recovery rate of around 44%. Critical discharge for sediment entrainment was obtained by detecting the movement of tracers placed immediately upstream of antennas. Virtual velocity was derived by knowing distances between the antennas and travel time of tracers. Results on initiation of motion show that the relationship between the size of transported tracers and the discharge measured at the time clasts were passing the stationary antenna is very weak. The influence of antecedent flows on incipient motion was thus investigated by dividing the highest discharge recorded between each PIT

  1. Source Water Flow Pathways In Forested, Mountain, Headwater Streams: A Link Between Sediment Movement Patterns And Stream Water Chemistry.

    Science.gov (United States)

    Martin, S.; Conklin, M. H.; Liu, F.

    2015-12-01

    Three years of continuous and discrete sediment and water quality data, from four forested, mountain, headwater catchments in the Sierra Nevada, is used to identify water sources, determine the importance of sub-surface flow pathways, detect any changes in source waters due to seasonal variation or drought, and link flow pathways with observed patterns of in-channel sediment movement within the study watersheds. Patterns in stream chemistry and turbidity point to infiltration as the dominant flow pathway within these catchments. Data support a flow pathway conceptual model in which precipitation water infiltrates into the shallow or deeper subsurface, increasing the hydraulic head of the water table and pushing pre-event water into the stream ahead of event water. Study catchments contain perennial streams and are characterized by a Mediterranean climate with a distinct wet and dry season. Sites are located in the rain-snow transition zone with snow making up 40 to 60 percent of average annual precipitation. Barring human disturbances such as logging/grazing (compaction) or fire (hydrophobicity), catchment soils have high infiltration capacities. Springs and seeps maintain baseflow during the summer low-flow season, and shifting chemical signals within the streams indicate the increased importance of sub-surface water sources during drought years. End-member mixing analysis was conducted to identify possible water end members. Turbidity hysteresis patterns described by previous studies show in-channel sources are dominant for discharge events year round, and there is no difference in fine sediment delivery to streams with or without a soil protecting layer of snow on the land surface. The dominance of sub-surface water sources and evidence for infiltration flow fits with turbidity data, as little material is reaching the stream due to erosive overland flow. An understanding of flow pathways provides a foundation for sustainable land use management in forested

  2. Mercury in Stream Sediments in the Sierra Nevada

    Science.gov (United States)

    Humphreys, R. D.; Tuffly, M. F.

    2001-12-01

    Mercury lost during California's gold rush is still found in Sierra Nevada rivers and streams. Mercury droplets and gold-mercury amalgam are found in stream bedrock fissures and along stream bedrock in watersheds that were subjected to intense hydraulic gold mining. Recreational gold miners report finding mercury puddles, sometimes containing mercury by the pound, on stream bedrock. The poster depicts where and how mercury was found and its spatial relationship to major hydraulic mines and dredge fields. Additional sampling is planned. Other studies are investigating the biological consequences of legacy mercury on the aquatic food chain. The positions of all confirmed locations were recorded and corrected using Trimble or CMT Global Positioning Systems (GPS). In the few instances were GPS positions could not be recorded, positions were determined by hand plotting from UGSG 7.5 minute topographic map.

  3. Impacts of biological diversity on sediment transport in streams (Invited)

    Science.gov (United States)

    Albertson, L. K.; Cardinale, B. J.

    2009-12-01

    The predominant view in many fields of natural science has long been that the diversity of life on Earth is simply a byproduct of physical variation in the environment. However, over the past several decades researchers have begun to compliment this view with new paradigms that suggest organisms not only respond to their abiotic environment, but also directly control rates of physical processes that define ecosystems. Even so, most of these studies have assumed that 'biology' is uniform - meaning, the influence of life can be described by a single parameter in physical models. But is it reasonable to assume that life can be condensed into a single parameter that describes how all of biology modifies physics? Is the influence of a tree on hillside erosion the same as a grass, or the effect of crab on bioturbation the same as that of a polychaete worm? Or alternatively, must we specifically account for the diversity of life that is perhaps the most striking feature of our planet? Here we present results from a study in which we examined how biological diversity of net-spinning caddisflies (Trichoptera:Hydropsychidae) influences sediment transport in streams. Caddisflies are insects that spend the larval portion of their life-cycle in the benthic habitat of streams where they construct silken catchnets across pore spaces between rocks to filter food particles. Because caddisflies can reach densities of 10,000 or more per m2 with each larva spinning thousands of silken threads between rocks, studies have shown that caddisflies reduce the probability of bed movement during high discharge events. We extended these results by simply asking whether two species have a greater impact on sediment mobility than one species. To address this question, we manipulated the presence of two caddisfly species (Artopsyche and Ceratopsyche) alone and in combination in model flumes having constant densities. After allowing larvae time to construct nets, we measured the force required to

  4. Stream Crossings

    Data.gov (United States)

    Vermont Center for Geographic Information — Physical measurements and attributes of stream crossing structures and adjacent stream reaches which are used to provide a relative rating of aquatic organism...

  5. Sources of fine sediment stored in agricultural lowland streams, Midwest, USA

    Science.gov (United States)

    Lamba, Jasmeet; Thompson, Anita M.; Karthikeyan, K.G.; Fitzpatrick, Faith A.

    2015-01-01

    Agricultural activities can accelerate the offsite transport of productive soil from fields leading to stream water quality degradation. Identification of the nature and relative contribution of different sources to fine-grained sediment (e.g., silts, clays) in streams is important to effectively focus agricultural best management practices in watersheds. Sediment fingerprinting techniques through the use of geochemical tracers are commonly used to differentiate relative contribution from various sources. Research was conducted in lowland streams in the Pleasant Valley watershed in South Central Wisconsin (USA) to identify provenance of fine-grained sediment deposits and evaluate the impact of land use on relative contributions from the following potential sources: cropland, pasture, woodland, and eroding stream banks. Results show that both agriculture (croplands and pastures) and eroding stream banks are primary sources to fine sediment deposits on the stream bed with contributions ranging from 19 to 100% and 0 to 81%, respectively. The increase in area under agricultural land use within a subwatershed results in greater contribution from agriculture (R2 = 0.846, p = 0.0034). Relative contributions from eroding stream banks increased with increasing area under grasslands and woodlands within a subwatershed (R2 = 0.814, p = 0.0055). Subwatersheds with greater mass of fine sediment deposited on the stream bed per unit area should be prioritized for best management practices. The conservation practices should be targeted to stream banks or croplands depending on the dominant source of fine sediment within a subwatershed. Site specific changes in relative contributions from different sources to fine-grained sediment in this watershed highlights the complexities involved in sediment transport dynamics. The nested sampling sites helped determine that sediment dynamics at the subwatershed scale need to be considered for application of targeted conservation

  6. Shading and sediment structure effects on stream metabolism resistance and resilience to infrequent droughts.

    Science.gov (United States)

    Zlatanović, Sanja; Fabian, Jenny; Premke, Katrin; Mutz, Michael

    2017-10-22

    Perennial, temperate, low-order streams are predicted to become intermittent as a result of irregular droughts caused by global warming and increased water demand. We hypothesize that stream metabolism changes caused by irregular droughts are linked to the shading and bed sediment structure of temperate streams. We set up 16 outdoor experimental streams with low or high shade conditions and streambeds either with alternating sorted patches of gravel and sand or homogeneous gravel-sand mix sediment structures. We assessed community respiration (CR), net ecosystem production (NEP) and periphyton biomass and structure (diatoms, green algae, cyanobacteria) in the course of 6weeks colonization, 6weeks desiccation, and 2.5weeks after rewetting. The heterotroph to autotroph (H:A) and fungi to bacteria (F:B) ratios in the microbial biofilm community were assessed at the end of the colonization and rewetting phases. Streams with different bed sediment structure were functionally similar; their metabolism under desiccation was controlled solely by light availability. During flow recession, all streams showed net heterotrophy. As desiccation progressed, NEP and CR decreased to zero. Desiccation altered the periphyton composition from predominantly diatoms to green algae and cyanobacteria, particularly in streams with low shade and mixed sediments. Rapid post-drought resilience of NEP was accompanied by high cyanobacteria and green algae growth in low shade, but poor total periphyton growth in high shade streams. Variable periphyton recovery was followed by increased H:A in relation to shading, and decreased F:B in relation to sediments structure. These shifts resulted in poor CR recovery compared to the colonization phase, suggesting a link between CR resilience and microbial composition changes. The links between drought effects, post-drought recovery, shading level, and streambed structure reveal the importance of low-order stream management under a changing climate and

  7. Metal-contaminated Sediment Effects on Biofilm Communities: Impairment of Multiple Stream Ecosystem Functions

    Science.gov (United States)

    Burton, G.; Costello, D.

    2012-12-01

    Photosynthetic biofilms are crucial drivers of many important stream ecosystem functions (e.g., primary and secondary production, N cycling), yet we have a limited understanding of how these critical communities respond to contaminated sediments. Divalent metals (e.g., Cu, Ni, Zn) are ubiquitous in urban streams and may be contributing to the decline in ecosystem function in urban waters. We exposed natural biofilm communities in five different streams to a common sediment amended with four concentrations of Ni and Cu. Contaminated sediments were placed into cups, covered with mesh disks for biofilm attachment, and secured to the streambed. After 6 weeks, biofilm-colonized disks were analyzed for net primary production (NPP), chlorophyll a, and metal content. Sediments below the biofilms were analyzed for total metals, acid volatile sulfide, and high-resolution vertical dissolved oxygen concentrations. Additional biofilm disks were separated from the sediment and fed to Lymnaea stagnalis to assess indirect effects of sediment metal on grazers. Among our five streams, we found variation in the biofilm response to metals with the most productive stream (Elm Creek) showing the strongest negative response to metal-contaminated sediment. Contaminated sediments in Elm Creek reduced biofilm growth, slowed primary production, and prevented penetration of oxygen into surface sediments. In the less productive streams, biofilms did not reduce NPP in the presence of sediment metal and there was still substantial penetration of oxygen into sediments; however, metals moved out of the sediment and accumulated in the biofilm. L. stagnalis exposed to metal-contaminated biofilms fed at a slower rate than those given clean biofilms. This study suggests that biofilms, and the biogeochemical cycles they drive, can potentially be impaired by contaminated sediment but the response is context dependent. Further, indirect dietary effects of contaminated sediment occur more widely than

  8. Climate change effects on phosphorus uptake by stream bed sediments

    Science.gov (United States)

    Climate change will likely increase growing season temperatures and the ratio of nitrogen (N) to phosphorus (P) loss from land to water. However, it is unknown how these factors influence the uptake of P or likely P-limitation of algal growth in streams. We sought to evaluate differences in biotic a...

  9. ONE-DIMENSIONAL HYDRODYNAMIC/SEDIMENT TRANSPORT MODEL FOR STREAM NETWORKS: TECHNICAL REPORT

    Science.gov (United States)

    This technical report describes a new sediment transport model and the supporting post-processor, and sampling procedures for sediments in streams. Specifically, the following items are described herein: EFDC1D - This is a new one-dimensional hydrodynamic and sediment tr...

  10. Sedgeunkedunk stream bed sediment particle diameter from 2007-08-15 to 2016-03-30 (NCEI Accession 0152487)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We are collecting stream channel geometry and bed sediment grain size distribution data at Sedgeunkedunk stream to evaluate physical habitat changes associated with...

  11. An analytical model for stream sediment transport: application to Murray and Murrumbidgee river reaches, Australia

    Science.gov (United States)

    Dietrich, Claude R.; Green, Timothy R.; Jakeman, Anthony J.

    1999-04-01

    The mechanisms controlling the flow of sediment in streams can be very complex and difficult to model with accuracy. Furthermore, data associated with the dominant sediment transport processes are often scarce. In this paper, we propose a model for the transport of suspended sediment in single stream reaches that permits a characterization of the dynamics of sediment sources and sinks, and routes concentrations through a stream network. We present a closed form, physically based, one-dimensional model that incorporates sediment advection, deposition, resuspension and lateral sources along a river reach. Data requirements for the model are modest, with parsimonious model structure involving only a few parameters. Thus, the model is relatively easy to calibrate and implement. An application of the model is illustrated using turbidity and flow data from two single reaches of the Murray and Murrumbidgee rivers in south-eastern Australia.

  12. Stream systems.

    Science.gov (United States)

    Jack E. Williams; Gordon H. Reeves

    2006-01-01

    Restored, high-quality streams provide innumerable benefits to society. In the Pacific Northwest, high-quality stream habitat often is associated with an abundance of salmonid fishes such as chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), and steelhead (O. mykiss). Many other native...

  13. Suspended-sediment and nutrient loads for Waiakea and Alenaio Streams, Hilo, Hawaii, 2003-2006

    Science.gov (United States)

    Presley, Todd K.; Jamison, Marcael T.J.; Nishimoto, Dale C.

    2008-01-01

    Suspended sediment and nutrient samples were collected during wet-weather conditions at three sites on two ephemeral streams in the vicinity of Hilo, Hawaii during March 2004 to March 2006. Two sites were sampled on Waiakea Stream at 80- and 860-foot altitudes during March 2004 to August 2005. One site was sampled on Alenaio Stream at 10-foot altitude during November 2005 to March 2006. The sites were selected to represent different land uses and land covers in the area. Most of the drainage area above the upper Waiakea Stream site is conservation land. The drainage areas above the lower site on Waiakea Stream, and the site on Alenaio Stream, are a combination of conservation land, agriculture, rural, and urban land uses. In addition to the sampling, continuous-record streamflow sites were established at the three sampling sites, as well as an additional site on Alenaio Stream at altitude of 75 feet and 0.47 miles upstream from the sampling site. Stage was measured continuously at 15-minute intervals at these sites. Discharge, for any particular instant, or for selected periods of time, were computed based on a stage-discharge relation determined from individual discharge measurements. Continuous records of discharge were computed at the two sites on Waiakea Stream and the upper site on Aleniao Stream. Due to non-ideal hydraulic conditions within the channel of Alenaio Stream, a continuous record of discharge was not computed at the lower site on Alenaio Stream where samples were taken. Samples were analyzed for suspended sediment, and the nutrients total nitrogen, dissolved nitrite plus nitrate, and total phosphorus. Concentration data were converted to instantaneous load values: loads are the product of discharge and concentration, and are presented as tons per day for suspended sediment or pounds per day for nutrients. Daily-mean loads were computed by estimating concentrations relative to discharge using graphical constituent loading analysis techniques. Daily

  14. Sediment loads and erosion in forest headwater streams of the Sierra Nevada, California

    Science.gov (United States)

    Carolyn T. Hunsaker; Daniel G. Neary

    2012-01-01

    Defining best management practices for forests requires quantification of the variability of stream sediment loads for managed and unmanaged forest conditions and their associated sediment sources. Although "best management practices" are used, the public has concerns about effects from forest restoration activities and commercial timber harvests. It is...

  15. Stream Evaluation

    Data.gov (United States)

    Kansas Data Access and Support Center — Digital representation of the map accompanying the "Kansas stream and river fishery resource evaluation" (R.E. Moss and K. Brunson, 1981.U.S. Fish and Wildlife...

  16. Uranium hydrogeochemical and stream sediment reconnaissance of the Mt. Hayes NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    Results of a hydrogeochemical and stream sediment reconnaissance of the Mt. Hayes quadrangle, Alaska, are presented. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. In this data release are location data, field analyses, and Laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendices A to D describe the sample media and summarize the analytical results for each medium. The data were subsetted by one of the Los Alamos National Laboratory (LANL) sorting programs into groups of stream sediment, lake sediment, stream water, lake water, and ground water samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1000000 scale maps of pertinent elements have been included in this report.

  17. Chlorinated pesticides in stream sediments from organic, integrated and conventional farms.

    Science.gov (United States)

    Shahpoury, Pourya; Hageman, Kimberly J; Matthaei, Christoph D; Magbanua, Francis S

    2013-10-01

    To determine if current sheep/beef farming practices affect pesticide residues in streams, current-use and legacy chlorinated pesticides were quantified in 100 sediment samples from 15 streams on the South Island of New Zealand. The study involved five blocks of three neighboring farms, with each block containing farms managed by organic, integrated and conventional farming practices. Significantly higher concentrations of dieldrin, ∑ endosulfans, ∑ current-use pesticides, and ∑ chlorinated pesticides were measured in sediments from conventional farms compared to organic and integrated farms. However, streams in the latter two farming categories were not pesticide-free and sometimes contained relatively high concentrations of legacy pesticides. Comparison of measured pesticide concentrations with sediment quality guidelines showed that, regardless of farming practice, mean pesticide concentrations were below the recommended toxicity thresholds. However, up to 23% of individual samples contained chlorpyrifos, endosulfan sulfate, ∑ DDT, dieldrin, or ∑ chlordane concentrations above these thresholds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Particle Size Characteristics of Fluvial Suspended Sediment in Proglacial Streams, King George Island, South Shetland Island

    Science.gov (United States)

    Szymczak, Ewa

    2017-12-01

    In this study, the characterization of particle size distribution of suspended sediment that is transported by streams (Ornithologist Creek, Ecology Glacier Creeks, Petrified Forest Creek, Czech Creek, Vanishing Creek, Italian Creek) in the area of the Arctowski Polish Antarctic Station is presented. During the first period of the summer season, the aforementioned streams are supplied by the melting snow fields, while later on, by thawing permafrost. The water samples were collected from the streams at monthly intervals during the Antarctic summer season (January - March) of 2016. The particle size distribution was measured in the laboratory with a LISST-25X laser diffraction particle size analyser. According to Sequoia Scientific Inc., LISST-25X can measure particle sizes (Sauter Mean Diameter) between 2.50 and 500 μm. The results of particle size measurements were analysed in relation to flow velocity (0.18–0.89 m/s), the cross-sectional parameters of the streams, suspended sediment concentration (0.06–167.22 mg/dm3) and the content of particulate organic matter (9.8–84.85%). Overall, the mean particle size ranged from 28.8 to 136 μm. The grain size of well-sorted sediments ranged from 0.076 to 0.57, with the skewness and kurtosis values varying from -0.1 to 0.4, and from 0.67 to 1.3, respectively. Based on the particle size characteristics of suspended sediment, the streams were divided into two groups. For most of the streams, the sediment was very well sorted, while fine sand and very fine sand were dominant fractions displaying symmetric and platykurtic distributions, respectively. Only in two streams, the suspended sediment consisted of silt-size grains, well or moderately well sorted, with coarse-skewness and mostly mesokurtic distribution. The C-M chart suggested that the transportation processes of suspended sediment included the suspended mode only. The grain-size distribution of suspended sediment was mainly influenced by the stream runoff

  19. Sediment contributions from floodplains and legacy sediments to Piedmont streams of Baltimore County, Maryland

    Science.gov (United States)

    Donovan, Mitchell; Miller, Andrew; Baker, Matthew; Gellis, Allen C.

    2015-01-01

    Disparity between watershed erosion rates and downstream sediment delivery has remained an important theme in geomorphology for many decades, with the role of floodplains in sediment storage as a common focus. In the Piedmont Province of the eastern USA, upland deforestation and agricultural land use following European settlement led to accumulation of thick packages of overbank sediment in valley bottoms, commonly referred to as legacy deposits. Previous authors have argued that legacy deposits represent a potentially important source of modern sediment loads following remobilization by lateral migration and progressive channel widening. This paper seeks to quantify (1) rates of sediment remobilization from Baltimore County floodplains by channel migration and bank erosion, (2) proportions of streambank sediment derived from legacy deposits, and (3) potential contribution of net streambank erosion and legacy sediments to downstream sediment yield within the Mid-Atlantic Piedmont.We calculated measurable gross erosion and deposition rates within the fluvial corridor along 40 valley segments from 18 watersheds with drainage areas between 0.18 and 155 km2 in Baltimore County, Maryland. We compared stream channel and floodplain morphology from lidar-based digital elevation data collected in 2005 with channel positions recorded on 1:2400 scale topographic maps from 1959–1961 in order to quantify 44–46 years of channel change. Sediment bulk density and particle size distributions were characterized from streambank and channel deposit samples and used for volume to mass conversions and for comparison with other sediment sources.Average annual lateral migration rates ranged from 0.04 to 0.19 m/y, which represented an annual migration of 2.5% (0.9–4.4%) channel width across all study segments, suggesting that channel dimensions may be used as reasonable predictors of bank erosion rates. Gross bank erosion rates varied from 43 to 310 Mg/km/y (median = 114) and

  20. High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

    2004-05-26

    Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

  1. Sources of sediment and phosphorus in stream flow of a highly productive dairy farmed catchment.

    Science.gov (United States)

    McDowell, R W; Wilcock, R J

    2007-01-01

    Both sediment and phosphorus (P) are important contaminants for surface water quality. Knowing the main sources of sediment and P loss within agricultural catchments enables mitigation practices to be better targeted. With this in mind seasonal loads of suspended sediment (SS), dissolved reactive P (DRP), total P (TP), and bioavailable P (BAP) were measured in a low gradient stream draining an intensively farmed New Zealand dairying catchment. Integrating in situ samplers were deployed to collect samples and the results merged with continuous flow data to calculate seasonal loads during 2005 through 2006. Flow rate, SS, and TP concentrations peaked in winter-spring and were lowest in summer-autumn. Concentrations of BAP in trapped sediment were greatest in autumn, contrasting with winter and spring when greater amounts of sediment were trapped, but with lower P enrichment. Analysis of (137)Cs and mixing model output showed that a major source of sediment and associated P in winter and spring was stream banks. Possible causes for this include trampling and destabilization by stock, channel straightening and sediment removal, and removal of riparian trees that stabilize banks. Modelling indicated that overland flow probably from topsoil (but could include sediment from lanes) contributed most sediment during summer and autumn. Remediation aimed at decreasing particulate P inputs to streams should focus on riparian protection measures, such as permanent stock exclusion and planting with shrubs and trees, ensuring runoff from lanes is minimized, and decreasing Olsen P to nearer optimum agronomic levels.

  2. E. coli Surface Properties Differ between Stream Water and Sediment Environments

    Directory of Open Access Journals (Sweden)

    Xiao Liang

    2016-11-01

    Full Text Available The importance of E. coli as an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences in E. coli cell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics of E. coli obtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically different E. coli strains (44 strains isolated from sediments and 33 strains isolated from water under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10mM and 22˚C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity and extracellular polymeric substance (EPS composition. Our results indicate that stream sediment E. coli had significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream water E. coli. A significant positive correlation was observed between hydrophobicity and EPS protein for stream sediment E. coli but not for stream water E. coli. Additionally, E. coli surviving in the same habitat tended to have significantly larger (GTG5 genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such as E. coli.

  3. Recent and historic sediment dynamics along Difficult Run, a suburban Virginia Piedmont stream

    Science.gov (United States)

    Hupp, Cliff R.; Noe, Gregory B.; Schenk, Edward R.; Bentham, Adam J.

    2012-01-01

    Suspended sediment is one of the major concerns regarding the quality of water entering the Chesapeake Bay. Some of the highest suspended-sediment concentrations occur on Piedmont streams, including Difficult Run, a tributary of the Potomac River draining urban and suburban parts of northern Virginia. Accurate information on catchment level sediment budgets is rare and difficult to determine. Further, the sediment trapping portion of sediment budget represents an important ecosystem service that profoundly affects downstream water quality. Our objectives, with special reference to human alterations to the landscape, include the documentation and estimation of floodplain sediment trapping (present and historic) and bank erosion along an urbanized Piedmont stream, the construction of a preliminary sediment balance, and the estimation of legacy sediment and recent development impacts. We used white feldspar markers to measure floodplain sedimentation rates and steel pins to measure erosion rates on floodplains and banks, respectively. Additional data were collected for/from legacy sediment thickness and characteristics, mill pond impacts, stream gaging station records, topographic surveying, and sediment density, texture, and organic content. Data were analyzed using GIS and various statistical programs. Results are interpreted relative to stream equilibrium affected by both post-colonial bottomland sedimentation (legacy) and modern watershed hardening associated with urbanization. Six floodplain/channel sites, from high to low in the watershed, were selected for intensive study. Bank erosion ranges from 0 to 470 kg/m/y and floodplain sedimentation ranges from 18 to 1369 kg/m/y (m refers to meters of stream reach). Upstream reaches are net erosional, while downstream reaches have a distinctly net depositional flux providing a watershed sediment balance of 2184 kg/m/y trapped within the system. The amounts of both deposition and erosion are large and suggest

  4. The mineralogy and trace element constituents of suspended stream sediments of the Linggi River Basin, Malaysia

    Science.gov (United States)

    Nather Khan, I. S. A.

    The mineralogy and trace element concentrations of suspended stream sediments were determined at selected stations in the Linggi River Basin, Malaysia, while conducting an intensive study on water quality and a biological assessment of water pollution in the basin. The minerals that were identified from the X-ray patterns of the suspended stream sediments are kaolinite, mica, feldspar and quartz. Kaolinite was the most abundant mineral, followed by mica. By considering mean concentrations of various trace elements, aluminum and manganese were the most abundant elements. Higher concentrations of copper and zinc at some stations were due to pollutants from the nearby Senawang Industrial Estate.

  5. Increasing floodplain connectivity through urban stream restoration increases nutrient and sediment retention

    Science.gov (United States)

    McMillan, Sara K.; Noe, Gregory

    2017-01-01

    Stream restoration practices frequently aim to increase connectivity between the stream channel and its floodplain to improve channel stability and enhance water quality through sediment trapping and nutrient retention. To measure the effectiveness of restoration and to understand the drivers of these functional responses, we monitored five restored urban streams that represent a range of channel morphology and restoration ages. High and low elevation floodplain plots were established in triplicate in each stream to capture variation in floodplain connectivity. We measured ecosystem geomorphic and soil attributes, sediment and nutrient loading, and rates of soil nutrient biogeochemistry processes (denitrification; N and P mineralization) then used boosted regression trees (BRT) to identify controls on sedimentation and nutrient processing. Local channel and floodplain morphology and position within the river network controlled connectivity with increased sedimentation at sites downstream of impaired reaches and at floodplain plots near the stream channel and at low elevations. We observed that nitrogen loading (both dissolved and particulate) was positively correlated with denitrification and N mineralization and dissolved phosphate loading positively influenced P mineralization; however, none of these input rates or transformations differed between floodplain elevation categories. Instead, continuous gradients of connectivity were observed rather than categorical shifts between inset and high floodplains. Organic matter and nutrient content in floodplain soils increased with the time since restoration, which highlights the importance of recovery time after construction that is needed for restored systems to increase ecosystem functions. Our results highlight the importance of restoring floodplains downstream of sources of impairment and building them at lower elevations so they flood frequently, not just during bankfull events. This integrated approach has the

  6. Seismic Investigation of Sediments Beneath Antarctic Ice Streams

    Science.gov (United States)

    Luthra, Tarun

    Fault zones are areas of localized deformation that accommodate strain in the Earth's crust accumulated over time due to tectonic motion or stress transfer from adjacent areas. Faults are traditionally considered to accommodate this strain by either constant slow movement (creep), or by rapid catastrophic failure events (earthquakes). The behavior of faults which produce earthquakes has been extensively studied, including characterization of the time and slip predictability of earthquakes, frequency-magnitude distributions, aftershock decay patterns, dynamic triggering, and frictional processes. Chance observations in global positioning system (GPS) data from the Vancouver Island area in 2001 revealed a new kind of fault slip that had not been considered before, slowslip events. Since those early observations, slow-slip events have been observed at most major subduction interfaces and even in glacial systems. In this dissertation, I strive to answer some of the fundamental questions about slow-slip systems. Little is known about the dynamics of these systems and how they operate. Scattered laboratory observations have provided clues, but this study is the first systematic examination of slow-slip earthquakes and their frictional behavior in the laboratory. I examine questions such as what controls how a fault zone will fail and what the velocity and normal stress sensitives are, then connect those mechanisms to observations from a natural slow-slip system beneath Whillans Ice Stream in western Antarctica. In chapter 1, I demonstrate how to modify the stiffness of the testing machine to create slow-slip events in the laboratory inartificial granular material. I also present a method to automatically calculate the stiffness of each slip event in a given experiment. Chapter 2 extends this work into a synthetic fault gouge material and carefully examines the sensitivity of the system to the stiffness of the testing apparatus. Chapter 3 introduces the new parameter of

  7. Biodegradation and attenuation of steroidal hormones and alkylphenols by stream biofilms and sediments

    Science.gov (United States)

    Writer, Jeffrey; Barber, Larry B.; Ryan, Joseph N.; Bradley, Paul M.

    2011-01-01

    Biodegradation of select endocrine-disrupting compounds (17β-estradiol, estrone, 17α-ethynylestradiol, 4-nonylphenol, 4-nonylphenolmonoexthoylate, and 4-nonylphenoldiethoxylate) was evaluated in stream biofilm, sediment, and water matrices collected from locations upstream and downstream from a wastewater treatment plant effluent discharge. Both biologically mediated transformation to intermediate metabolites and biologically mediated mineralization were evaluated in separate time interval experiments. Initial time intervals (0–7 d) evaluated biodegradation by the microbial community dominant at the time of sampling. Later time intervals (70 and 185 d) evaluated the biodegradation potential as the microbial community adapted to the absence of outside energy sources. The sediment matrix was more effective than the biofilm and water matrices at biodegrading 4-nonylphenol and 17β-estradiol. Biodegradation by the sediment matrix of 17α-ethynylestradiol occurred at later time intervals (70 and 185 d) and was not observed in the biofilm or water matrices. Stream biofilms play an important role in the attenuation of endocrine-disrupting compounds in surface waters due to both biodegradation and sorption processes. Because sorption to stream biofilms and bed sediments occurs on a faster temporal scale (185 d), these compounds can accumulate in stream biofilms and sediments.

  8. Research gaps related to forest management and stream sediment in the United States.

    Science.gov (United States)

    Anderson, Christopher J; Lockaby, B Graeme

    2011-02-01

    Water quality from forested landscapes tends to be very high but can deteriorate during and after silvicultural activities. Practices such as forest harvesting, site preparation, road construction/use, and stream crossings have been shown to contribute sediment, nutrients, and other pollutants to adjacent streams. Although advances in forest management accompanied with Best Management Practices (BMPs) have been very effective at reducing water quality impacts from forest operations, projected increases in demand for forest products may result in unintended environmental degradation. Through a review of the pertinent literature, we identified several research gaps related to water yield, aquatic habitat, sediment source and delivery, and BMP effectiveness that should be addressed for streams in the United States to better understand and address the environmental ramifications of current and future levels of timber production. We explored the current understanding of these topics based on relevant literature and the possible implications of increased demand for forest products in the United States.

  9. Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

    Science.gov (United States)

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    1999-01-01

    Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

  10. Analysis of storm runoff-sediment yield of a 1st order stream basin in ...

    African Journals Online (AJOL)

    The aim of this study is to examine the relationship between storm flow discharge and storm sediment yield of a 1st order stream basin in the degraded forested part of Obafemi Awolowo University, Ile-Ife. The study was carried out between August and October, 2002 and six storm events that occurred during the day were ...

  11. Delivery of suspended sediment and associated phosphorus and heavy metals to small rural Danish streams

    DEFF Research Database (Denmark)

    Laubel, A. R.

    The aim of this study is to examine delivery pathways for suspended sediment, and particulate phosphorus (P) and heavy metals from open rural areas to small Danish streams. A further aim is to quantify the contribution from different path-ways and source areas. Such studies are useful as a basis...

  12. Constituent loads in small streams: the process and problems of estimating sediment flux

    Science.gov (United States)

    R. B. Thomas

    1989-01-01

    Constituent loads in small streams are often estimated poorly. This is especially true for discharge-related constituents like sediment, since their flux is highly variable and mainly occurs during infrequent high-flow events. One reason for low-quality estimates is that most prevailing data collection methods ignore sampling probabilities and only partly account for...

  13. Provenance Tracing of Glacial Sediment from the Foundation, Academy, and Recovery Ice Streams, Weddell Sea, Antarctica

    Science.gov (United States)

    Cirone, A.; Brachfeld, S. A.; Cortes, I.; Verhagen, C. M.; Williams, T.; Hemming, S. R.; Licht, K.; van de Flierdt, T.

    2016-12-01

    The Ronne-Filchner Ice Shelf is the second largest ice shelf in Antarctica and drains ice from both West and East Antarctica. This sector has the potential to generate significant sea level rise in the face of global climate change. This project seeks to advance our understanding of ice dynamics by "fingerprinting" ice streams that drain into the Ronne-Filchner Ice Shelf and gain insight into the bedrock composition beneath the Antarctic Ice Sheet. The first step is to develop tracers of glacial debris, which can be used to correlate ice rafted debris in the Weddell Sea with ice streams on land. Till samples were collected from moraines adjacent to the Foundation, Academy, and Recovery ice streams during a December 2014 field season, and marine sediment samples from the ice shelf edge were taken from surface sediment grabs and piston cores from the International Weddell Sea Ocean Expedition. This collaborative project is developing a comprehensive suite of tracers. The ongoing study presented here focuses on bulk elemental compositions, texture and composition of iron-oxide grains, and sediment magnetic properties of the till samples. Till from the northern margin of Recovery ice stream has high Al/Ti ratios (21-22) and high values of the chemical index of alteration (CIA 70 -71). However, till from the southern margin of Recovery ice stream has Al/Ti values of 13-15 and elevated Mn/Al and Fe/Al ratios. Academy till has the highest Al/Ti values (23-24) and the highest Fe/Ti values (9-10), while Foundation ice stream till has a greater range of Al/Ti ratios (15-21) and CIA values (61-70). Iron oxide grains in the coarse silt and sand fraction from both terrestrial and marine samples have been extracted to form polished grain mounts, which will be analyzed for grain texture and geochemistry. Sediment magnetic analyses include magnetic susceptibility, magnetic grain size, and remanence carrying abilities of bulk sediment and individual lithologies represented by the

  14. Heavy metal contamination of stream water and sediment in the Taejon area

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Woong [Paichai University, Taejon (Korea, Republic of); Lee, Hyun Koo [Chungnam National University, Taejon (Korea, Republic of)

    1996-08-31

    Associated with the rapid pace of overpopulation and industrialization is the increase of municipal and industrial wastewater and heavy metal contamination from these point sources have received much attention in the Taejon area. To reduce the environmental problems, 21 stream sediments from Gap-chun, Yudeung-chun, Yusung-chun and Keum river have been analyzed for Cd, Cu, Pb and Zn. The results show that heavy metal concentrations are high in sediments from the Sintanjin and Taehwa Industrial Complex area with particular reference to 1388 {mu}g/g Cu in the stream sediment of Yusung-chun. When the geochemical map drawn from the Kriging technique of these data are compared with the industrialization and urbanization index map, high concentrations of heavy metals are found in stream sediments in industrialized areas resulting from the accumulation of heavy metals from the polluting factories. Concentrations of Cu in sediments from the Taehwa Industrial Complex area and those of Zn in sediments from the Sintanjin Complex area higher than EPA standard in the U.S.A and may be the potential sources of pollution in Keum river with possible implications to human health. For the speciation of Cu, Pb and Zn, the high proportions of exchangeable phase of Cu and Zn in stream sediments indicate that the metals originate not from parent materials but from wastewater and exist as the adsorbed phase on the surface of sediments. These metals are easily dissolved into the water by the reaction and relative amounts of easily dissolved phase of metals are in the order of Cu = Zn > Pb. (author). 17 refs., 4 tabs., 7 figs.

  15. First post-fire flush in a Mediterranean temporary stream: source ascription in bed sediments

    Science.gov (United States)

    Estrany Bertos, Joan; García-Comendador, Julián; Fortesa, Josep; Calsamiglia, Aleix; Garcias, Francesca

    2017-04-01

    First flushes can be of great importance for suspended-sediment transport in fluvial systems of drylands, being temporary streams a characteristic feature of Mediterranean basins. After a wildfire, storm flows may enhance runoff delivery to channels and then increasing the first-flush effect. 137Cs and 210Pbex were used as tracers for recognizing the first post-fire flush effect in the source ascription of bed sediments temporarily stored in a Mediterranean temporary stream severely affected by a wildfire. Thirty potential sediment source samples were collected along the main stem of a catchment located in Mallorca (Spain) during a field campaign developed some weeks after the wildfire. The sample collection was designed considering the wildfire affection, and also distinguishing between soil surface and channel bank. To quantify the relative source contribution to the bed sediment temporarily stored, five sediment samples -deposited during the first storm occurred three months after the wildfire- were collected into the bed stream of the main channel. The 137Cs and 210Pbex concentrations were measured by gamma spectrometry. Then, a linear mixing model was used to establish the relative contribution of each source type to the bed sediments discerning between the most upstream and the downstream parts of the catchment. Post-fire first-flush effect was generated by a torrential event with a suspended-sediment concentration peak ca. 33,618 mg L-1, although transmission losses under a very low runoff coefficient (1%) promoted sediment deposition. Significant differences were observed in fallout radionuclide concentrations between burned surface soil and channel bank samples (p 0.05). Source ascription in bed sediments in the middle stream shows that 67% was generated in burned hillslopes, reaching 75% in the downstream part because downstream propagation of the sediment derived from the burned area. Bed sediments were mostly generated in burned hillslopes because of

  16. Recreational Stream Crossing Effects on Sediment Delivery and Macroinvertebrates in Southwestern Virginia, USA

    Science.gov (United States)

    Kidd, Kathryn R.; Aust, W. Michael; Copenheaver, Carolyn A.

    2014-09-01

    Trail-based recreation has increased over recent decades, raising the environmental management issue of soil erosion that originates from unsurfaced, recreational trail systems. Trail-based soil erosion that occurs near stream crossings represents a non-point source of pollution to streams. We modeled soil erosion rates along multiple-use (hiking, mountain biking, and horseback riding) recreational trails that approach culvert and ford stream crossings as potential sources of sediment input and evaluated whether recreational stream crossings were impacting water quality based on downstream changes in macroinvertebrate-based indices within the Poverty Creek Trail System of the George Washington and Jefferson National Forest in southwestern Virginia, USA. We found modeled soil erosion rates for non-motorized recreational approaches that were lower than published estimates for an off-road vehicle approach, bare horse trails, and bare forest operational skid trail and road approaches, but were 13 times greater than estimated rates for undisturbed forests and 2.4 times greater than a 2-year old clearcut in this region. Estimated soil erosion rates were similar to rates for skid trails and horse trails where best management practices (BMPs) had been implemented. Downstream changes in macroinvertebrate-based indices indicated water quality was lower downstream from crossings than in upstream reference reaches. Our modeled soil erosion rates illustrate recreational stream crossing approaches have the potential to deliver sediment into adjacent streams, particularly where BMPs are not being implemented or where approaches are not properly managed, and as a result can negatively impact water quality below stream crossings.

  17. Get In and Get Out: Assessing Stream Sediment Loading from Short Duration Forest Harvest Operations and Rapid Haul Road Decommissioning.

    Science.gov (United States)

    Corrigan, A.; Silins, U.; Stone, M.

    2016-12-01

    Best management practices (BMPs) and associated erosion control measures for mitigating sediment impacts from forestry roads and road-stream crossings are well documented. While rapid road decommissioning after forestry operations may serve to limit broader impacts on sediment production in high value headwater streams, few studies have evaluated the combined effects of accelerated harvest operations and rapid retirement of logging roads and road-stream crossings on stream sediment. The objectives of this study were to evaluate the initial impacts of these strategies on fine sediment loading and fate during a short duration harvesting operation in 3 headwater sub-catchments in the southwestern Rocky Mountains of Alberta, Canada. A multi-pronged sampling approach (ISCOs, event focused grab sampling, continuous wash load sampling, and stream bed sediment intrusion measurements) was used to measure sediment loading and deposition in streambeds upstream and downstream of road-stream bridge crossings during harvest operations (2015) and after road and bridge crossing retirement (2016). Sediment production from forestry roads was generally much lower than has been reported from other studies in similar settings. Average total suspended solids (TSS) downstream of the bridge crossings were actually lower (-3.28 g/L; -0.704 g/L) than upstream of two bridge crossings while in-stream sediment sources contributed to elevated sediment downstream of a third road-stream crossing. Minimal in stream sediment impacts from forest harvest and road-stream crossings was likely a reflection of combined factors including a) employment of erosion control BMPs to roads and bridge crossings, b) rapid decommissioning of roads and crossings to limit exposure of linear land disturbance features, and c) drier El Niño climatic conditions during the study.

  18. Bed sediment-associated trace metals in an urban stream, Oahu, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, R.A. [Hawaii Univ., Honolulu, HI (United States). Geomorphology Lab.

    2000-04-01

    Of the 117 stream and lake systems sampled nationwide, fish from Manoa Stream on Oahu, Hawaii, have consistenly shown the highest Pb concentrations. Therefore a detailed study was conducted to examine total metal contents in bed sediments from a 5.8-km stretch of Manoa Stream. A total of 123 samples (<63 {mu}m) were examined for 18 elements and 14 samples for 21 elements. Selected samples were also examined using different leach solutions to examine metal phase associations. All trace metal data, computations of enrichment ratios and the modified index of geoaccumulation point to mineralogical control for Cr and Ni; minor anthropogenic contamination for Ba, Cd, Cu, Hg and Zn; and a very strong contamination signal for Pb. Maximum Pb contents (up to 1080 mg kg{sup -1}) were associated with anthropogenic material dumping in minor tributaries, storm sewer sediments and sediments in the 'lower' section of the basin. Proportionally Pb had the highest non-residual component of elements examined; dominantly in the reducible phase associated with Mn and amorphous Fe oxyhydroxides. The contamination signal was typically lowest in the 'undisturbed' headwater reach of the basin (above 5.1 km) with significant increases throughout the 'residential' and 'commercial-institutional' zones of the mid-basin. The spatial pattern of bed sediment contamination and evidence from storm sewer-outlet sediments strongly indicates that Pb, and to a lesser degree some other metals, is still being transported to the stream and the primary agent is soil erosion and transport of metals sorbed to sediments. The primary source of sediment-associated metals is considered to be the automobile, though other minor sources can not be ruled out. (orig.)

  19. Toxicity and genotoxicity of water and sediment from streams on dotted duckweed (Landoltia punctata

    Directory of Open Access Journals (Sweden)

    R Factori

    Full Text Available Most rivers are used as a source to supply entire cities; the quality of water is directly related to the quality of tributaries. Unfortunately men have neglected the importance of streams, which receive domestic and industrial effluents and transport nutrients and pesticides from rural areas. Given the complexity of the mixtures discharged into these water bodies, this study aimed to evaluate the quality of water and sediment of ten tributaries of Pirapó River, in Maringá, Paraná State, Brazil. To this end, the free-floating macrophyte Landoltia punctata (G. Meyer Les & D.J.Crawford was used as test organism in microcosm, and the toxicity of water and sediment samples was evaluated by the relative growth rate, dry/fresh biomass ratio, and genotoxic effects (comet assay. Samples of water and sediment of each stream were arranged in microcosms with L. punctata. Seven days later, plants were collected for analysis. Nutrient levels were higher than the reference location, indicating eutrophication, but the results indicated a toxic effect for only three streams, and a genotoxic effect for all streams.

  20. Uranium hydrogeochemical and stream sediment reconnaissance of the Philip Smith Mountains NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    1981-09-01

    Results of a hydrogeochemical and stream sediment reconnaissance of the Philip Smith Mountains NTMS quadrangle, Alaska are presented. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. In this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data were subsetted by one of the Los Alamos National Laboratory (LANL) sorting programs into groups of stream sediment and lake sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1000000 scale maps of pertinent elements have been included in this report.

  1. Hydrogeochemical and stream sediment special reconnaissance report for the Deep Creek Mountains, Nevada and Utah

    Energy Technology Data Exchange (ETDEWEB)

    Qualheim, B.

    1979-04-01

    This report represents the results of the reconnaissance sampling of the Deep Creek Mountains of western Utah. The Deep Creek range is located in the northwest corner of the Delta NTMS 1:250,000 and the southwestern corner of the Tooele NTMS 1:250,000 sheets and covers an area of 1750 km/sup 2/. Samples collected in this study include dry and wet stream sediments and water from available streams, wells, and springs. The samples were analyzed for uranium, as well as 15 to 20 trace elements, using neutron activation techniques. In addition, field and laboratory measurements were made on the water samples. Analytical data and field measurements are presented in tabular hard copy and fiche format. Water-sample site locations, water-sample uranium concentrations, sediment-sample site locations, and sediment-sample uranium concentrations are shown on separate overlays.

  2. Uranium hydrogeochemical and stream sediment reconnaissance of the Yakutat NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    1981-09-01

    Results of a hydrogeochemical and stream sediment reconnaissance of the Yakutat NTMS quadrangle, Alaska are presented. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. In this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data were subsetted by one of the Los Alamos National Laboratory (LANL) sorting programs into groups of stream sediment and lake sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1000000 scale maps of pertinent elements have been included in this report.

  3. Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa.

    Science.gov (United States)

    Polidoro, Beth A; Comeros-Raynal, Mia T; Cahill, Thomas; Clement, Cassandra

    2017-03-15

    The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution. Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants (pesticides, PAHs, phthalates) in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury. Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since 2006, was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Heavy metals in water, sediment and tissues of Leuciscus cephalus from a stream in southwestern Turkey.

    Science.gov (United States)

    Demirak, Ahmet; Yilmaz, Fevzi; Tuna, A Levent; Ozdemir, Nedim

    2006-06-01

    Concentrations of heavy metals (Cd, Cr, Cu, Pb and Zn) were measured in water, bottom sediment and tissues (muscle and gills) of Leuciscus cephalus from the Dipsiz stream in the Yatagan basin (southwestern Turkey), the site of a thermal power plant. Results for levels in water were compared with national and international water quality guidelines, as well as literature values were reported for streams and rivers. Comparisons were made of metal concentrations in water and sediment with those in the muscle and gills of L. cephalus caught from the Dipsiz stream. We found that there was metal accumulation in the gills compared to the muscle. Concentrations of Cd, Pb, Zn and Cr in the gills were higher than that in the muscle; however, Cu levels were higher in muscle than that in gills. Concentrations of heavy metals in L. cephalus muscle were below the legal limits for human consumption, although Cr, Pb and Zn levels in the gills were above the limits in the fish taken from the Dipsiz stream. On the other hand, no correlation was found between metal concentrations in water and sediment or between metal concentrations in water and muscle and gills of L. cephalus. A positive correlation was found between concentrations of Cu and Zn in the sediment and in fish tissue, whereas there was no relationship between other metal concentrations in the sediment and water, and muscle and gills of L. cephalus. As with water, Pb and Cd concentrations in particular were higher in sediment than that in background levels. The results show that the pollutants from the thermal power plant may be a source of these elements.

  5. Relationship between bifenthrin sediment toxic units and benthic community metrics in urban California streams.

    Science.gov (United States)

    Hall, Lenwood W; Anderson, Ronald D

    2013-08-01

    The objective of this study was to use ecologically relevant field measurements for determining the relationship between bifenthrin sediment toxic units (TUs) (environmental concentrations/Hyalella acute LC50 value) and 15 benthic metrics in four urban California streams sampled from 2006 to 2011. Data from the following four California streams were used in the analysis: Kirker Creek (2006, 2007), Pleasant Grove Creek (2006, 2007, and 2008), Arcade Creek (2009, 2010, and 2011), and Salinas streams (2009, 2010, and 2011). The results from univariate analysis of benthic metrics versus bifenthrin TU calculations for the four California streams with multiple-year datasets combined by stream showed that there were either nonsignificant relationships or lack of metric data for 93 % of cases. For 7 % of the data (4 cases) where significant relationships were reported between benthic metrics and bifenthrin TUs, these relationships were ecologically meaningful. Three of these significant direct relationships were an expression of tolerant benthic taxa (either % tolerant taxa or tolerance values, which are similar metrics), which would be expected to increase in a stressed environment. These direct significant tolerance relationships were reported for Kirker Creek, Pleasant Grove Creek, and Arcade Creek. The fourth significant relationship was an inverse relationship between taxa richness and bifenthrin TUs for the 3-year Pleasant Grove Creek dataset. In summary, only a small percent of the benthic metric × bifenthrin TU relationships were significant for the four California streams. Therefore, the general summary conclusion from this analysis is that there is no strong case for showing consistent meaningful relationships between various benthic metrics used to characterize the status of benthic communities and bifenthrin TUs for these four California streams.

  6. Mercury in Fish, Bed Sediment, and Water from Streams Across the United States, 1998-2005

    Science.gov (United States)

    Scudder, Barbara C.; Chasar, Lia C.; Wentz, Dennis A.; Bauch, Nancy J.; Brigham, Mark E.; Moran, Patrick W.; Krabbenhoft, David P.

    2009-01-01

    Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg). Each site was sampled one time during seasonal low flow. Predator fish were targeted for collection, and composited samples of fish (primarily skin-off fillets) were analyzed for total Hg (THg), as most of the Hg found in fish tissue (95-99 percent) is MeHg. Samples of bed sediment and stream water were analyzed for THg, MeHg, and characteristics thought to affect Hg methylation, such as loss-on-ignition (LOI, a measure of organic matter content) and acid-volatile sulfide in bed sediment, and pH, dissolved organic carbon (DOC), and dissolved sulfate in water. Fish-Hg concentrations at 27 percent of sampled sites exceeded the U.S. Environmental Protection Agency human-health criterion of 0.3 micrograms per gram wet weight. Exceedances were geographically widespread, although the study design targeted specific sites and fish species and sizes, so results do not represent a true nationwide percentage of exceedances. The highest THg concentrations in fish were from blackwater coastal-plain streams draining forests or wetlands in the eastern and southeastern United States, as well as from streams draining gold- or Hg-mined basins in the western United States (1.80 and 1.95 micrograms THg per gram wet weight, respectively). For unmined basins, length-normalized Hg concentrations in largemouth bass were significantly higher in fish from predominantly undeveloped or mixed-land-use basins compared to urban basins. Hg concentrations in largemouth bass from unmined basins were correlated positively with basin percentages of evergreen forest and also woody wetland, especially with

  7. Meta-analysis: abundance, behavior, and hydraulic energy shape biotic effects on sediment transport in streams.

    Science.gov (United States)

    Albertson, L K; Allen, D C

    2015-05-01

    An increasing number of studies have emphasized the need to bridge the disciplines of ecology and geomorphology. A large number of case studies show that organisms can affect erosion, but a comprehensive understanding of biological impacts on sediment transport conditions is still lacking. We use meta-analysis to synthesize published data to quantify the effects of the abundance, body size, and behavior of organisms on erosion in streams. We also explore the influence of current velocity, discharge, and sediment grain size on the strength of biotic effects on erosion. We found that species that both increase erosion (destabilizers) and decrease erosion (stabilizers) can alter incipient sediment motion, sediment suspension, and sediment deposition above control conditions in which the organisms were not present. When abundance was directly manipulated, these biotic effects were consistently stronger in the higher abundance treatment, increasing effect sizes by 66%. Per capita effect size and per capita biomass were also consistently positively correlated. Fish and crustaceans were the most studied organisms, but aquatic insects increased the effect size by 550 x compared to other types of organisms after accounting for biomass. In streams with lower discharge and smaller grain sizes, we consistently found stronger biotic effects. Taken collectively, these findings provide synthetic evidence that biology can affect physical processes in streams, and these effects can be mediated by hydraulic energy. We suggest that future studies focus on understudied organisms, such as biofilms, conducting experiments under realistic field conditions, and developing hypotheses for the effect of biology on erosion and velocity currents in the context of restoration to better understand the forces that mediate physical disturbances in stream ecosystems.

  8. Arsenic in the health of ecosystems: spatial distribution in water, sediment and aquatic biota of Pampean streams.

    Science.gov (United States)

    Rodríguez Castro, M C; Marcó P, L; Ranieri, M C; Vázquez, C; Giorgi, A

    2017-10-07

    A survey of arsenic and phosphorus in Pampean streams of Buenos Aires province was performed. Nitrates and ammonia were also determined. Stream water was sampled as well as stream sediment and filamentous algae. Results show that 32 streams exceeded the arsenic recommended guidelines for human consumption of 10 μg L(-1) and six exceeded recommended values for aquatic organisms' protection of 50 μg L(-1). The average concentration found was 36.54 μg L(-1) and areas with more concentration of As are located in the southern region of the province, in streams that are tributaries of the Atlantic Ocean. Other regions with high As concentration are the Matanza River tributaries and the Arrecifes River tributaries. No differences of As concentration was found between stream sediments. Also, no seasonal pattern of As concentration was observed in one stream sampled during a year, but a positive correlation between As and the conductivity (p = 0.0002) and pH (p = 0.01) of the streams was found. Also, As bioaccumulation was detected for all the algae sampled, but no correlation between As accumulated and As in the stream water was found. Ammonia levels exceeded recommended guidelines for human consumption in the Argentinean law in 30 streams. The characterization performed in this study provides relevant information on the distribution of arsenic and its origin and mobility.

  9. Understanding the combined influence of fine sediment and glyphosate herbicide on stream periphyton communities.

    Science.gov (United States)

    Magbanua, Francis S; Townsend, Colin R; Hageman, Kimberly J; Lange, Katharina; Lear, Gavin; Lewis, Gillian D; Matthaei, Christoph D

    2013-09-15

    Pesticides and deposited fine sediment have independently been associated with changes in relative abundance and species richness in aquatic ecosystems, but the interplay between these two stressors in agricultural streams is poorly understood. A 28-day experiment in outdoor stream mesocosms examined the effects of four levels each of fine sediment coverage (0, 25, 75, 100%) and glyphosate-based herbicide concentration (0, 50, 200, 370 μg/L) on periphyton communities (algae and bacteria) in a fully factorial, repeated-measures design. Our aims were to determine whether (i) increased levels of sediment and glyphosate had individual and/or additive effects, (ii) increased sediment reduced the toxicity of glyphosate (antagonistic multiple stressor interaction), or (iii) sediment-adsorbed glyphosate prolonged the effects of exposure (synergistic interaction). We also assigned all algal taxa to three ecological guilds (low-profile, high-profile and motile growth forms) and separately determined their responses to the treatments. As individual stressors, sediment addition affected all algal community-level metrics, whereas glyphosate addition only affected algal community evenness. Bacterial taxon richness was unaffected by either stressor. In combination, however, significant overall sediment by glyphosate interactions were detected, demonstrating synergistic (algal evenness, high-profile and motile guilds) or antagonistic effects (low-profile guild). Our experiment underscores the importance of considering both structural and functional indicators, including algal guild representation, when assessing the mechanisms by which periphyton communities respond to multiple stressors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Microbial exopolymers in sediments of a second order stream: Njoro ...

    African Journals Online (AJOL)

    Results indicated significant correlations between various carbohydrates with sediment parameters such as grain sizes, total organic nitrogen (TON) and total organic carbon (TOC) but only exopolymeric substances (EPS) (ethanol fraction of colloidal EDTA) were correlated to bacterial abundances. This implied that EPS is ...

  11. Multielement chemical and statistical analyses from a uranium hydrogeochemical and stream-sediment survey in and near the Elkhorn Mountains, Jefferson County, Montana; Part II, Stream sediments

    Science.gov (United States)

    Suits, V.J.; Wenrich, K.J.

    1982-01-01

    Fifty-two stream-sediment samples, collected from an area south of Helena, Jefferson County, Montana, were sieved into two size fractions (50 ppm for the fine fraction) were encountered in samples from the Warm Springs Creek drainage area, along Prickly Pear Creek near Welmer and Golconda Creeks and along Muskrat Creek. All groups showed a significant correlation at the 99 percent confidence level (r between 0.73 and 0.77) between U and Th. Uranium was found to correlate significantly only with Th (as mentioned above) and with -Ni in the fine fraction of the volcanics group. U correlates significantly with -Al2O3, Ba, organic C, -K2O, -Sr and Y in both size fractions for the Boulder batholith. Correlations between U and each of several elements differ for the fine and coarse fractions of the Boulder batholith group, suggesting that the U distribution in these stream sediments is in large part controlled by grain size. Correlations were found between U and CaO, Cr, Fe203, -Na2O, Sc, -SiO2, TiO2, Yb and Zr in the coarse fraction but not in the fine fraction. U correlates weakly (to the 90% confidence level, crc<.37) with -Co and -Cu in the fine but not the coarse fraction. These results are compared to a previous study in the northern Absaroka mountains. Correlation coefficients between all other elements determined from these samples are also shown in Tables 12 to 15.

  12. Modeling wood dynamics, jam formation, and sediment storage in a gravel-bed stream

    Science.gov (United States)

    Eaton, B. C.; Hassan, M. A.; Davidson, S. L.

    2012-12-01

    In small and intermediate sized streams, the interaction between wood and bed material transport often determines the nature of the physical habitat, which in turn influences the health of the stream's ecosystem. We present a stochastic model that can be used to simulate the effects on physical habitat of forest fires, climate change, and other environmental disturbances that alter wood recruitment. The model predicts large wood (LW) loads in a stream as well as the volume of sediment stored by the wood; while it is parameterized to describe gravel bed streams similar to a well-studied field prototype, Fishtrap Creek, British Columbia, it can be calibrated to other systems as well. In the model, LW pieces are produced and modified over time as a result of random tree-fall, LW breakage, LW movement, and piece interaction to form LW jams. Each LW piece traps a portion of the annual bed material transport entering the reach and releases the stored sediment when the LW piece is entrained and moved. The equations governing sediment storage are based on a set of flume experiments also scaled to the field prototype. The model predicts wood loads ranging from 70 m3/ha to more than 300 m3/ha, with a mean value of 178 m3/ha: both the range and the mean value are consistent with field data from streams with similar riparian forest types and climate. The model also predicts an LW jam spacing that is consistent with field data. Furthermore, our modeling results demonstrate that the high spatial and temporal variability in sediment storage, sediment transport, and channel morphology associated with LW-dominated streams occurs only when LW pieces interact and form jams. Model runs that do not include jam formation are much less variable. These results suggest that river restoration efforts using engineered LW pieces that are fixed in place and not permitted to interact will be less successful at restoring the geomorphic processes responsible for producing diverse, productive

  13. Spatial and temporal variability in stream sediment loads using examples from the Gros Ventre Range, Wyoming, USA

    Science.gov (United States)

    Sandra E. Ryan; Mark K. Dixon

    2007-01-01

    Sediment transport rates (dissolved, suspended, and bedload) measured over the course of several years are reported for two streams in the Gros Ventre Mountain range in western Wyoming, USA: Little Granite and Cache Creeks. Both streams drain watersheds that are in relatively pristine environments. The sites are about 20km apart, have runoff dominated by snowmelt and...

  14. Uraniam hydrogeochemical and stream sediment reconnaissance of the Wiseman NTMS Quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    1981-09-01

    This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Wiseman NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form through the Grand Junction Office Information System at Oak Ridge National Laboratory. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendix A describes the sample media and summarizes the analytical results for each medium. The data were subdivided by one of the Los Alamos National Laboratory (LANL) sorting programs of Zinkl and others (198a) into stream sediment samples.

  15. Distribution of non-marine diatoms in surface sediments of streams in Socotra Island, Yemen

    OpenAIRE

    Abdelfattah A. Zalat; Mohammed A. Al-Wosabi

    2011-01-01

    Abundance and species composition of non-marine benthic diatom assemblages were studied from surface sediments samples of 11 streams distributed in Socotra Island, located in the northwest Indian Ocean. A total of 145 diatom species, representing 44 genera, were identified. The overall diatom communities appear to be the first recorded off the island. Pennales and non-planktonic taxa were most dominant over centrales and planktonic forms, both in diversity of genera and species. The majority ...

  16. Biodegradation of 17β-estradiol, estrone and testosterone in stream sediments

    Science.gov (United States)

    Bradley, Paul M.; Barber, Larry B.; Chapelle, Francis H.; Gray, James L.; Kolpin, Dana W.; McMahon, Peter B.

    2009-01-01

    Biodegradation of 17β-estradiol (E2), estrone (E1), and testosterone (T) was investigated in three wastewater treatment plant (WWTP) affected streams in the United States. Relative differences in the mineralization of [4-14C] substrates were assessed in oxic microcosms containing saturated sediment or water-only from locations upstream and downstream of the WWTP outfall in each system. Upstream sediment demonstrated significant mineralization of the “A” ring of E2, E1, and T, with biodegradation of T consistently greater than that of E2 and no systematic difference in E2 and E1 biodegradation. “A” ring mineralization also was observed in downstream sediment, with E1 and T mineralization being substantially depressed relative to upstream samples. In marked contrast, E2 mineralization in sediment immediately downstream from the WWTP outfalls was more than double that in upstream sediment. E2 mineralization was observed in water, albeit at insufficient rate to prevent substantial downstream transport. The results indicate that, in combination with sediment sorption processes which effectively scavenge hydrophobic contaminants from the water column and immobilize them in the vicinity of the WWTP outfall, aerobic biodegradation of reproductive hormones can be an environmentally important mechanism for nonconservative (destructive) attenuation of hormonal endocrine disruptors in effluent-affected streams.

  17. Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

    Science.gov (United States)

    Brakebill, J.W.; Ator, S.W.; Schwarz, G.E.

    2010-01-01

    We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain. ?? 2010 American Water Resources Association. No claim to original U.S. government works.

  18. Hydrogeochemical and stream sediment reconnaissance basic data for Hutchinson NTMS Quadrangle, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-27

    Results of a reconnaissance geochemical survey of the Hutchinson Quadrangle, Kansas are reported. Field and laboratory data are presented for 592 groundwater and 616 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. The groundwater data indicate that the southwestern corner of the quadrangle offers some potential for uranium mineralization. Five large clusters of groundwaters with high uranium values occur here. Wells in the southwestern corner produce waters from the Permian Nippewalla Group and the overlying Kiowa Shale that often contain high concentrations of arsenic, molybdenum, selenium, and vanadium which are known to associate with uranium in sandstone deposits. The stream sediment data indicate that most of the uranium and thorium anomalies occur as placer-type concentrations associated with Quaternary deposits. There are three areas that show groups of high uranium and thorium concentrations in the stream sediments; one in the northeast in Chase, Lyon, Morris, and Wabaunsee Counties; one in Dickinson and Geary Counties; and the third, the large area west of long. 97/sup 0/ 20' W.

  19. Influence of sediment chemistry and sediment toxicity on macroinvertebrate communities across 99 wadable streams of the Midwestern USA

    Science.gov (United States)

    Moran, Patrick W.; Nowell, Lisa H.; Kemble, Nile E.; Mahler, Barbara J.; Waite, Ian R.; Van Metre, Peter C.

    2017-01-01

    Simultaneous assessment of sediment chemistry, sediment toxicity, and macroinvertebrate communities can provide multiple lines of evidence when investigating relations between sediment contaminants and ecological degradation. These three measures were evaluated at 99 wadable stream sites across 11 states in the Midwestern United States during the summer of 2013 to assess sediment pollution across a large agricultural landscape. This evaluation considers an extensive suite of sediment chemistry totaling 274 analytes (polycyclic aromatic hydrocarbons, organochlorine compounds, polychlorinated biphenyls, polybrominated diphenyl ethers, trace elements, and current-use pesticides) and a mixture assessment based on the ratios of detected compounds to available effects-based benchmarks. The sediments were tested for toxicity with the amphipod Hyalella azteca (28-d exposure), the midge Chironomus dilutus (10-d), and, at a few sites, with the freshwater mussel Lampsilis siliquoidea (28-d). Sediment concentrations, normalized to organic carbon content, infrequently exceeded benchmarks for aquatic health, which was generally consistent with low rates of observed toxicity. However, the benchmark-based mixture score and the pyrethroid insecticide bifenthrin were significantly related to observed sediment toxicity. The sediment mixture score and bifenthrin were also significant predictors of the upper limits of several univariate measures of the macroinvertebrate community (EPT percent, MMI (Macroinvertebrate Multimetric Index) Score, Ephemeroptera and Trichoptera richness) using quantile regression. Multivariate pattern matching (Mantel-like tests) of macroinvertebrate species per site to identified contaminant metrics and sediment toxicity also indicate that the sediment mixture score and bifenthrin have weak, albeit significant, influence on the observed invertebrate community composition. Together, these three lines of evidence (toxicity tests, univariate metrics, and

  20. Differing Levels of Forestry Best Management Practices at Stream Crossing Structures Affect Sediment Delivery and Installation Costs

    Directory of Open Access Journals (Sweden)

    Brian C. Morris

    2016-03-01

    Full Text Available Forestry best management practices (BMPs are used to reduce sedimentation from forest stream crossings. Three BMP treatments (BMP−, BMP-std, and BMP+ were applied to three forest road stream crossings (bridge, culvert, and ford. BMP− did not meet existing BMP guidelines, BMP-std met standard recommendations, and BMP+ treatments exceeded recommendations. Following BMP applications, three simulated rainfall intensities (low, medium, and high were applied in order to evaluate sediment delivery from crossing type and BMP level. During rainfall simulation, sediment concentrations (mg/L were collected with automated samplers and discharge (L/s was estimated to calculate total sediment loading. Costs of stream crossings and BMP levels were also quantified. Mean sediment associated with the three stream crossings were 3.38, 1.87, and 0.64 Mg for the BMP−, BMP-std, and BMP+ levels, respectively. Ford, culvert, and bridge crossings produced 13.04, 12.95, and 0.17 Mg of sediment during construction, respectively. BMP enhancement was more critical for sediment control at the culvert and ford crossings than at the bridge. Respective costs for BMP−, BMP-std, and BMP+ levels were $5,368, $5,658, and $5,858 for the bridge; $3,568, $4,166 and $4,595 for the culvert; and $180, $420 and $1,903 for the ford. Costs and sediment values suggest that current standard BMP levels effectively reduce stream sediment while minimizing costs.

  1. The Role of Alkalinity Inputs in the Composition of Sediments in AN Acid Mine Drainage Remediated Stream: Hewett Fork, Ohio

    Science.gov (United States)

    Lopez, D. L.; Korenowsky, R. K.; Kruse, N.; Bowman, J.

    2012-12-01

    Hewett Fork, a tributary of Raccoon Creek in SE Ohio, is severely impacted by acid mine drainage. This stream is being actively treated using a calcium oxide doser. In this work, we report the results of our investigations into the chemical effect of remediation in the stream throughout an evaluation of the chemical composition of its sediments. Results show that the grain size of the sediments is finer in the areas where high alkalinity loads enter the stream, at the output from the doser and downstream of the confluence with alkaline tributaries. The composition of heavy metals (magnesium, aluminum, calcium, nickel, zinc, manganese, potassium, lead, chromium, copper, cobalt and arsenic) is higher in concentration in the fine-grained sediments where alkalinity enters the stream, forming two peaks of high sediment concentration along the stream, one at the doser and the second after the confluence with alkaline tributaries. Iron has a different behavior with a higher sediment concentration downstream from the doser at the areas where the grain size is larger, due to the kinetics of the oxidation process for the formation of iron (III) minerals. These results suggest that in remediation of acid-mine-drainage impacted streams, alkalinity inputs along and oxidation processes are important for the storage of heavy metals in the sediments.

  2. Origin of Stream Bed Sediments in Northwest New Jersey: Factors of Land Use and Source Determined by Trace Element Analysis

    Science.gov (United States)

    Pope, G. A.; Starks, L. M.; Torres, A. J.; Galster, J. C.; Feng, H.; Wu, M. S.

    2012-12-01

    Streams in northern New Jersey span a broad range of environments and land covers, including urban, agriculture, wetlands, and forest. Stream sediments receive input from these environments, and indicate pulses or stages of land use change, or stability. In this project, we use trace elements, including rare earth elements, to fingerprint sediment sources and differentiate between land use as well as immediate sources of sediment, such as stream banks, floodplains, uplands, or urban inputs. Samples of stream bed, stream bank, floodplain sediments, and urban and upland soils were obtained from eight locations in the Flat Brook, Rockaway River, and Wallkill River watersheds in Sussex and Morris counties in New Jersey. Samples were prepared for trace element analysis with inductively coupled plasma mass spectrometry (ICPMS). Element content was compared to land use, sediment source, and a stream stability index (the Rapid Geomorphic Assessment, RGA). Several elements (V, Cr, Ni, Sr, Pb) were statistically significant at distinguishing between land use. Zr and W were able to distinguish sediment source (i.e. floodplain, bank, upland, etc.) with statistical confidence. Related to stream and bank stability, the RGA showed significant positive correlation with Cr and Co content (increasing Cr and Co with increasing instability), indicating these elements as good proxy indicators for bank erosion. Ongoing studies of element ratios, combined with Cs-136 and Pb-210 activity levels by gamma detector, will further refine the sediment characterization, with an eventual goal of approximating a sediment budget across different land uses and identifying hot spots that deliver disproportionately high amounts of sediment.; Increase in Co content corresponds to an increase in channel and bank instability, indicated by increasing RGA value.

  3. River longitudinal profiles and bedrock incision models: Stream power and the influence of sediment supply

    Science.gov (United States)

    Sklar, Leonard; Dietrich, William E.

    The simplicity and apparent mechanistic basis of the stream power river incision law have led to its wide use in empirical and theoretical studies. Here we identify constraints on its calibration and application, and present a mechanistic theory for the effects of sediment supply on incision rates which spotlights additional limitations on the applicability of the stream power law. On channels steeper than about 20%, incision is probably dominated by episodic debris flows, and on sufficiently gentle slopes, sediment may bury the bedrock and prevent erosion. These two limits bound the application of the stream power law and strongly constrain the possible combination of parameters in the law. In order to avoid infinite slopes at the drainage divide in numerical models of river profiles using the stream power law it is commonly assumed that the first grid cell is unchanneled. We show, however, that the size of the grid may strongly influence the calculated equilibrium relief. Analysis of slope-drainage area relationships for a river network in a Northern California watershed using digital elevation data and review of data previously reported by Hack reveal that non-equilibrium profiles may produce well defined slope-area relationships (as expected in equilibrium channels), but large differences between tributaries may point to disequilibrium conditions. To explore the role of variations in sediment supply and transport capacity in bedrock incision we introduce a mechanistic model for abrasion of bedrock by saltating bedload. The model predicts that incision rates reach a maximum at intermediate levels of sediment supply and transport capacity. Incision rates decline away from the maximum with either decreasing supply (due to a shortage of tools) or increasing supply (due to gradual bed alluviation), and with either decreasing transport capacity (due to less energetic particle movement) or increasing transport capacity (due less frequent particle impacts per unit bed

  4. Case Study-Removal and Restoration of In-stream Sediment Ponds

    Science.gov (United States)

    Presentation from 2011 on goals and objectives of Case study was to restore impacted streams to a proper dimension, pattern, and profile with an emphasis on restoration of stream and riparian habitats.

  5. Hydrogeochemical and stream sediment reconnaissance basic data report for Williams NTMS quadrangle, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wagoner, J.L.

    1979-02-01

    Wet and dry sediments were collected throughout the 18,500-km/sup 2/arid-to-semiarid region and water samples at available streams, springs, and wells. Samples were collected between August 1977 and January 1978. Results of neutron activation analyses of uranium and trace elements and other field and laboratory analyses are presented in tabular hardcopy and microfiche format. The report includes six full-size overlays for use with the Williams NTMS 1:250,000 quadrangle. Sediment samples are divided into five general groups according to the source rock from which the sediment was derived. Background uranium concentrations for the quadrangle are relatively low, ranging from 1.91 to 2.40 ppM, with the highest associated with the Precambrian igneous and metamorphic complexes of the Basin and Range province. Uranium correlates best with the rare-earth elements and iron, scandium, titanium, and manganese. Known uranium occurrences are not readily identified by the stream sediment data.

  6. Fine sediment influence on salmonid spawning habitat in a lowland agricultural stream: a preliminary assessment.

    Science.gov (United States)

    Soulsby, C; Youngson, A F; Moir, H J; Malcolm, I A

    2001-01-29

    Spawning habitat utilized by Atlantic Salmon (Salmo salar) and Sea Trout (Salmo trutta) was characterized in a 1.6-km reach of the Newmills Burn, a small, highly canalized tributary of the River Don in Aberdeenshire. The Newmills Burn is typical of the intensively farmed lower sub-catchments of the major salmon rivers on the east coast of Scotland. Such streams have substantial potential in providing spawning and juvenile habitat for salmonids, with high redd densities resulting in egg deposition rates of > 5 m2. However, in comparison with upland spawning tributaries draining less intensively managed catchments, canalization and intensive cultivation has seriously degraded the physical characteristics of aquatic habitats in many streams. In the Newmills Burn, spawning gravels have a relatively high (> 20% by mass) fine sediment (open gravel matrices (simulated redds) can occur within a week, and probably within a single moderate to large storm event. Appreciable, but small, deposition of organic and silt/clay particles can also affect spawning gravels. Egg mortalities in redds following spawning are variable, but can be as high as 86% in the Newmills Burn. This may be related to fine sediment infiltration, reduced permeability of spawning gravels and reduced oxygen supply to ova. It appears that the main cause of high influx is sediment loads mobilized from intensively managed land. It is suggested that fundamental changes to the management of agricultural land is required if fish habitats are to be improved and degraded streams are allowed to re-naturalize. The need for closely focused investigations of the causal relationships between fine sediment infiltration and egg survival is stressed.

  7. Warmer night-time temperature promotes microbial heterotrophic activity and modifies stream sediment community.

    Science.gov (United States)

    Freixa, Anna; Acuña, Vicenç; Casellas, Maria; Pecheva, Stoyana; Romaní, Anna M

    2017-09-01

    Diel temperature patterns are changing because of global warming, with higher temperatures being predicted to be more pronounced at night. Biological reactions are temperature dependent, with some occurring only during the daylight hours (e.g., light photosynthesis) and other during the entire day (e.g., respiration). Consequently, we expect the modification of daily temperature cycles to alter microbial biological reactions in stream sediments. Here, we aimed to study the effect of warming and changes of the diel temperature patterns on stream sediment biofilm functions tied to organic carbon decomposition, as well as on biofilm meiofaunal community structure. We performed an eight-week experiment with 12 artificial streams subjected to three different diel temperature patterns: warming, warmer nights and control. Significant effects of warming on biofilm function and structure were mainly detected in the long term. Our results showed that warming altered biofilm function, especially in the warmer nights' treatment, which enhanced β-glucosidase enzyme activity. Interestingly, clear opposite diel patterns were observed for dissolved organic carbon and β-glucosidase activity, suggesting that, at night, sediment bacteria quickly consume the input of photosynthetic dissolved organic carbon labile compounds created during light-time. The biofilm structure was also altered by warming, as both warming and warmer night treatments enhanced copepod abundance and diminished abundances of turbellaria and nematodes, which, in turn, controlled bacterial, algal and ciliate communities. Overall, we conclude that warming has strong effect on sediment biofilm structure and enhanced microbial organic matter degradation which might, consequently, affect higher trophic levels and river carbon cycling. © 2017 John Wiley & Sons Ltd.

  8. From streets to streams: assessing the toxicity potential of urban sediment by particle size

    Science.gov (United States)

    Corsi, Steven R.; Selbig, William R.; Roger T. Bannerman,; ,

    2013-01-01

    Urban sediment can act as a transport mechanism for a variety of pollutants to move towards a receiving water body. The concentrations of these pollutants oftentimes exceed levels that are toxic to aquatic organisms. Many treatment structures are designed to capture coarse sediment but do not work well to similarly capture the fines. This study measured concentrations of select trace metals and PAHs in both the silt and sand fractions of urban sediment from four sources: stormwater bed, stormwater suspended, street dirt, and streambed. Concentrations were used to assess the toxic potential of sediment based on published sediment quality guidelines. All sources of sediment showed some level of toxic potential with stormwater bed sediment the highest followed by stormwater suspended, street dirt, and streambed. Both metal and PAH concentration distributions were highly correlated between the four sampling locations suggesting the presence of one or perhaps only a few sources of these pollutants which remain persistent as sediment is transported from street to stream. Comparison to other forms of combustion- and vehicle-related sources of PAHs revealed coal tar sealants to have the strongest correlation, in both the silt and sand fractions, at all four sampling sites. This information is important for environmental managers when selecting the most appropriate Best Management Practice (BMP) as a way to mitigate pollution conveyed in urban stormwater from source to sink.

  9. Modern sedimentation patterns in Lake El'gygytgyn, NE Russia, derived from surface sediment and inlet streams samples

    Directory of Open Access Journals (Sweden)

    V. Wennrich

    2013-01-01

    Full Text Available Lake El'gygytgyn/NE Russia holds a continuous 3.58 Ma sediment record, which is regarded as the most long-lasting climate archive of the terrestrial Arctic. Based on multi-proxy geochemical, mineralogical, and granulometric analyses of surface sediment, inlet stream and bedrock samples, supplemented by statistical methods, major processes influencing the modern sedimentation in the lake were investigated. Grain-size parameters and chemical elements linked to the input of feldspars from acidic bedrock indicate a wind-induced two-cell current system as major driver of sediment transport and accumulation processes in Lake El'gygytgyn. The distribution of mafic rock related elements in the sediment on the lake floor can be traced back to the input of weathering products of basaltic rocks in the catchment. Obvious similarities in the spatial variability of manganese and heavy metals indicate sorption or co-precipitation of these elements with Fe and Mn hydroxides and oxides. But the similar distribution of organic matter and clay contents might also point to a fixation to organic components and clay minerals. An enrichment of mercury in the inlet streams might be indicative of neotectonic activity around the lake. The results of this study add to the fundamental knowledge of the modern lake processes of Lake El'gygytgyn and its lake-catchment interactions, and thus, yield crucial insights for the interpretation of paleo-data from this unique archive.

  10. Hydrologic influence on sediment transport of low-gradient, forested headwater streams in central Louisiana

    Science.gov (United States)

    Philip Saksa; Yi Jun Xu; Richard Stich

    2013-01-01

    Extensive research has been conducted on headwater streams in regions with high topographic variation. However, relatively few studies have examined low-gradient headwater stream systems, such as those existing in much of the southeastern Coastal Plain. The focus of this study is to investigate spatial and temporal variation of headwater stream hydrology in a low-...

  11. Restoration of Lowland Streams

    DEFF Research Database (Denmark)

    Osborne, L. L.; Bayley, P. B.; Higler, L. W. G.

    1993-01-01

    Sammenskrivning af resultater fra symposium: Lowland Streams Restoration Workshop, Lund, Sweden, August 1991......Sammenskrivning af resultater fra symposium: Lowland Streams Restoration Workshop, Lund, Sweden, August 1991...

  12. Identification of Ti- anomaly in stream sediment geochemistry using of stepwise factor analysis and multifractal model in Delijan district, Iran

    Directory of Open Access Journals (Sweden)

    Feridon Ghadimi

    2016-06-01

    Full Text Available In this study, 115 samples taken from the stream sediments were analyzed for concentrations of As, Co, Cr, Cu, Ni, Pb, W, Zn, Au, Ba, Fe, Mn, Sr, Ti, U, V and Zr. In order to outline mineralization-derived stream sediments, various mapping techniques including fuzzy factor score, geochemical halos and fractal model were used. Based on these models, concentrations of Co, Cr, Ni, Zn, Ba, Fe, Mn, Ti, U, V and Zr showed anomaly and anomaly distributed in the andesitic volcanic rocks. In addition, an anomaly map of each element was also ascertained the most ideal results for the exploration of deposits. Anomaly element associations can be successfully used in future geochemical exploration works. According to stream sediment study, it characterized high anomaly of Ti deposits in the central and northern of the area and it confirmed by study of heavy mineral in sediments and litho-geochemical study in the andesitic unites.

  13. Can rapid assessment protocols be used to judge sediment impairment in gravel-bed streams? A commentary

    Science.gov (United States)

    Thomas E. Lisle; John M. Buffington; Peter R. Wilcock; Kristin Bunte

    2015-01-01

    Land management agencies commonly use rapid assessments to evaluate the impairment of gravel-bed streams by sediment inputs from anthropogenic sources. We question whether rapid assessment can be used to reliably judge sediment impairment at a site or in a region. Beyond the challenges of repeatable and accurate sampling, we argue that a single metric or protocol is...

  14. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus

    NARCIS (Netherlands)

    Laarhoven, Bob; Elissen, H.J.H.; Temmink, H.; Buisman, C.J.N.

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water

  15. A study of the effects of implementing agricultural best management practices and in-stream restoration on suspended sediment, stream habitat, and benthic macroinvertebrates at three stream sites in Surry County, North Carolina, 2004-2007-Lessons learned

    Science.gov (United States)

    Smith, Douglas G.; Ferrell, G.M.; Harned, Douglas A.; Cuffney, Thomas F.

    2011-01-01

    The effects of agricultural best management practices and in-stream restoration on suspended-sediment concentrations, stream habitat, and benthic macroinvertebrate assemblages were examined in a comparative study of three small, rural stream basins in the Piedmont and Blue Ridge Physiographic Provinces of North Carolina and Virginia between 2004 and 2007. The study was designed to assess changes in stream quality associated with stream-improvement efforts at two sites in comparison to a control site (Hogan Creek), for which no improvements were planned. In the drainage basin of one of the stream-improvement sites (Bull Creek), several agricultural best management practices, primarily designed to limit cattle access to streams, were implemented during this study. In the drainage basin of the second stream-improvement site (Pauls Creek), a 1,600-foot reach of the stream channel was restored and several agricultural best management practices were implemented. Streamflow conditions in the vicinity of the study area were similar to or less than the long-term annual mean streamflows during the study. Precipitation during the study period also was less than normal, and the geographic distribution of precipitation indicated drier conditions in the southern part of the study area than in the northern part. Dry conditions during much of the study limited opportunities for acquiring high-flow sediment samples and streamflow measurements. Suspended-sediment yields for the three basins were compared to yield estimates for streams in the southeastern United States. Concentrations of suspended sediment and nutrients in samples from Bull Creek, the site where best management practices were implemented, were high compared to the other two sites. No statistically significant change in suspended-sediment concentrations occurred at the Bull Creek site following implementation of best management practices. However, data collected before and after channel stabilization at the Pauls

  16. Suspended sediment and turbidity after road construction/improvement and forest harvest in streams of the Trask River Watershed Study, Oregon

    Science.gov (United States)

    Ivan Arismendi; Jeremiah D. Groom; Maryanne Reiter; Sherri L. Johnson; Liz Dent; Mark Meleason; Alba Argerich; Arne E. Skaugset

    2017-01-01

    Transport of fine-grained sediment from unpaved forest roads into streams is a concern due to the potential negative effects of additional suspended sediment on aquatic ecosystems. Here we compared turbidity and suspended sediment concentration (SSC) dynamics in five nonfish bearing coastal Oregon streams above and below road crossings, during three consecutive time...

  17. Uranium hydrogeochemical and stream sediment reconnaissance of the Survey Pass NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Shettel, D.L. Jr.; Langfeldt, S.L.; Youngquist, C.A.; D' Andrea, R.F. Jr.; Zinkl, R.J. (comps.)

    1981-09-01

    This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Survey Pass NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form through the Grand Junction Office Information System at Oak Ridge National Laboratory. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume. These data are, however, available on the magnetic tape. Appendix A describes the sample media and summarizes the analytical results for each medium. The data were subdivided by one of the Los Alamos National Laboratory (LANL) sorting programs of Zinkl and others (1981a) into stream sediment samples. For the group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1000000 scale maps of pertinent elements have been included in this report. In addition, maps showing results of multivariate statistical analyses have been included. Further information about the HSSR program in general, or about the LANL portion of the program in particular, can be obtained in quarterly or semiannual program progress reports on open-file at DOE's Technical Library in Grand Junction. Information about the field and analytical procedures used by LANL during sample collection and analysis may be found in any HSSR data release prepared by the LANL and will not be included in this report.

  18. Characterization of Archaeal Community in Contaminated and Uncontaminated Surface Stream Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Porat, Iris [ORNL; Vishnivetskaya, Tatiana A [ORNL; Mosher, Jennifer J [ORNL; Brandt, Craig C [ORNL; Yang, Zamin [ORNL; Brooks, Scott C [ORNL; Liang, Liyuan [ORNL; Drake, Meghan M [ORNL; Podar, Mircea [ORNL; Brown, Steven D [ORNL; Palumbo, Anthony Vito [ORNL

    2010-01-01

    Abstract Archaeal communities from mercury and uranium-contaminated freshwater stream sediments were characterized and compared to archaeal communities present in an uncontaminated stream located in the vicinity of Oak Ridge, TN, USA. The distribution of the Archaea was determined by pyrosequencing analysis of the V4 region of 16S rRNA amplified from 12 streambed surface sediments. Crenarchaeota comprised 76% of the 1,670 archaeal sequences and the remaining 24% were from Euryarchaeota. Phylogenetic analysis further classified the Crenarchaeota as a Freshwater Group, Miscellaneous Crenarchaeota group, Group I3, Rice Cluster VI and IV, Marine Group I and Marine Benthic Group B; and the Euryarchaeota into Methanomicrobiales, Methanosarcinales, Methanobacteriales, Rice Cluster III, Marine Benthic Group D, Deep Sea Hydrothermal Vent Euryarchaeota 1 and Eury 5. All groups were previously described. Both hydrogen- and acetate-dependent methanogens were found in all samples. Most of the groups (with 60% of the sequences) described in this study were not similar to any cultivated isolates, making it difficult to discern their function in the freshwater microbial community. A significant decrease in the number of sequences, as well as in the diversity of archaeal communities was found in the contaminated sites. The Marine Group I, including the ammonia oxidizer Nitrosopumilus maritimus, was the dominant group in both mercury and uranium/nitrate-contaminated sites. The uranium-contaminated site also contained a high concentration of nitrate, thus Marine Group I may play a role in nitrogen cycle.

  19. Modeling hydrologic controls on sulfur processes in sulfate-impacted wetland and stream sediments

    Science.gov (United States)

    Ng, G.-H. C.; Yourd, A. R.; Johnson, N. W.; Myrbo, A. E.

    2017-09-01

    Recent studies show sulfur redox processes in terrestrial settings are more important than previously considered, but much remains uncertain about how these processes respond to dynamic hydrologic conditions in natural field settings. We used field observations from a sulfate-impacted wetland and stream in the mining region of Minnesota (USA) to calibrate a reactive transport model and evaluate sulfur and coupled geochemical processes under contrasting hydrogeochemical scenarios. Simulations of different hydrological conditions showed that flux and chemistry differences between surface water and deeper groundwater strongly control hyporheic zone geochemical profiles. However, model results for the stream channel versus wetlands indicate sediment organic carbon content to be the more important driver of sulfate reduction rates. A complex nonlinear relationship between sulfate reduction rates and geochemical conditions is apparent from the model's higher sensitivity to sulfate concentrations in settings with higher organic content. Across all scenarios, simulated e- balance results unexpectedly showed that sulfate reduction dominates iron reduction, which is contrary to the traditional thermodynamic ladder but corroborates recent experimental findings by Hansel et al. (2015) that "cryptic" sulfur cycling could drive sulfate reduction in preference over iron reduction. Following the thermodynamic ladder, our models shows that high surface water sulfate slows methanogenesis in shallow sediments, but field observations suggest that sulfate reduction may not entirely suppress methane. Overall, our results show that sulfate reduction may serve as a major component making up and influencing terrestrial redox processes, with dynamic hyporheic fluxes controlling sulfate concentrations and reaction rates, especially in high organic content settings.

  20. Distribution of non-marine diatoms in surface sediments of streams in Socotra Island, Yemen

    Directory of Open Access Journals (Sweden)

    Abdelfattah A. Zalat

    2011-11-01

    Full Text Available Abundance and species composition of non-marine benthic diatom assemblages were studied from surface sediments samples of 11 streams distributed in Socotra Island, located in the northwest Indian Ocean. A total of 145 diatom species, representing 44 genera, were identified. The overall diatom communities appear to be the first recorded off the island. Pennales and non-planktonic taxa were most dominant over centrales and planktonic forms, both in diversity of genera and species. The majority of recognized diatoms are of cosmopolitan distribution. The predominant diatom flora in the surface sediment samples follow: Synedra ulna, Synedra longissima, Encyonema caespitosum, Encyonema silesiacum, Encyonemopsis microcephala, Mastogloia braunii, Mastogloia dansei, Mastogloia elliptica, Navicula cryptocephala, Navicula cryptotenella, Navicula rhynchocephala, Navicula cincta, Nitzschia amphibian, Nitzschia frustulum, Nitzschia perminuta, Cocconeis placentula, Pleurosira laevis and Staurosirella pinnata. These are found in addition to the common occurrence of Amphora coffeaeformis, Amphora Montana, Anomoeoneis sphaerophora, Cyclotella meneghiniana, Cymbella affinis, Diploneis elliptica, Encyonema mesianum, Diploneis smithii, Gomphonema gracile, Gomphonema parvulum, Kobayasia subtilissima, Mastogloia smithii, Navicula minuscule, Navicula notha, Navicula tenelloides, Nitzschia obtuse, Nitzschia palea, Nitzschia scalaris, Synedra nana, Tryblionella acuminate, Tryblionella granulate and Tryblionella punctata. Multivariate statistical techniques including detrended correspondence and cluster analyses were used to summarize changes in the diatom assemblages present in the examined streams. The results indicated six major diatom assemblages with a variation in dominant species. Each assemblage reflects distinctive environmental conditions based on salinity preference of the recognized and dominant.

  1. Geochemical orientation survey of stream sediment, stream water, and ground water near uranium prospects, Monticello area, New York. National Uranium Resource Evaluation Program

    Energy Technology Data Exchange (ETDEWEB)

    Rose, A. W.; Smith, A. T.; Wesolowski, D.

    1982-08-01

    A detailed geochemical test survey has been conducted in a 570 sq km area around six small copper-uranium prospects in sandstones of the Devonian Catskill Formation near Monticello in southern New York state. This report summarizes and interprets the data for about 500 stream sediment samples, 500 stream water samples, and 500 ground water samples, each analyzed for 40 to 50 elements. The groundwater samples furnish distinctive anomalies for uranium, helium, radon, and copper near the mineralized localities, but the samples must be segregated into aquifers in order to obtain continuous well-defined anomalies. Two zones of uranium-rich water (1 to 16 parts per billion) can be recognized on cross sections; the upper zone extends through the known occurrences. The anomalies in uranium and helium are strongest in the deeper parts of the aquifers and are diluted in samples from shallow wells. In stream water, copper and uranium are slightly anomalous, as in an ore factor derived from factor analysis. Ratios of copper, uranium, and zinc to conductivity improve the resolution of anomalies. In stream sediment, extractable uranium, copper, niobium, vanadium, and an ore factor furnish weak anomalies, and ratios of uranium and copper to zinc improve the definition of anomalies. The uranium/thorium ratio is not helpful. Published analyses of rock samples from the nearby stratigraphic section show distinct anomalies in the zone containing the copper-uranium occurrences. This report is being issued without the normal detailed technical and copy editing, to make the data available to the public before the end of the National Uranium Reconnaissance Evaluation program.

  2. Data on Mercury in Water, Bed Sediment, and Fish from Streams Across the United States, 1998-2005

    Science.gov (United States)

    Bauch, Nancy J.; Chasar, Lia C.; Scudder, Barbara C.; Moran, Patrick W.; Hitt, Kerie J.; Brigham, Mark E.; Lutz, Michelle A.; Wentz, Dennis A.

    2009-01-01

    The U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and Toxic Substances Hydrology Programs conducted the National Mercury Pilot Study in 1998 to examine relations of mercury (Hg) in water, bed sediment and fish in streams across the United States, including Alaska and Hawaii. Water and bed-sediment samples were analyzed for total Hg (THg), methylmercury (MeHg), and other constituents; fish were analyzed for THg. Similar sampling was conducted at additional streams across the country in 2002 and 2004-05. This report summarizes sample collection and processing protocols, analytical methods, environmental data, and quality-assurance data for stream water, bed sediment, and fish for these national studies. To extend the geographic coverage of the data, this report also includes four regional USGS Hg studies conducted during 1998-2001 and 2004. The environmental data for these national and regional Hg studies are provided in an electronic format.

  3. Uranium hydrogeochemical and stream-sediment reconnaissance of the Big Delta NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L. C.; D& #x27; Andrea, Jr., R. F.; Zinkl, R. J.; Shettel, Jr., D. L.; Langfeldt, S. L. [comps.

    1982-02-01

    This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Big Delta NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. These machine-readable data, as well as quarterly or semiannual program progress reports containing further information on the HSSR program in general, or on the Los Alamos National Laboratory (LANL) portion of the program in particular, are available from DOE's Technical Library at its Grand Junction Area Office. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume; these data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data have been subdivided by one of the Los Alamos National Laboratory sorting programs of Zinkl and others (1981a) into groups of stream-sediment and lake-sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1,000,000 scale maps of pertinent elements have been included in this report. Also included are maps showing results of multivariate statistical analyses. Information on the field and analytical procedures used by the Los Alamos National Laboratory during sample collection and analysis may be found in any HSSR data release prepared by the Laboratory and will not be included in this report.

  4. Uranium hydrogeochemical and stream-sediment reconnaissance of the Mt. Michelson NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Zinkl, R.J.; Shettel, D.L. Jr.; Langfeldt, S.L.; Hardy, L.C.; D' Andrea, R.F. Jr. (comps.)

    1982-04-01

    This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Mt. Michelson NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. These machine-readable data, as well as quarterly or semiannual program progress reports containing further information on the HSSR program in general, or on the Los Alamos National Laboratory (LANL) portion of the program in particular, are available from DOE's Technical Library at its Grand Junction Area Office. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume; these data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data have been subdivided by one of the Los Alamos National Laboratory sorting programs of Zinkl and others (1981a) into groups of stream-sediment and lake-sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1,000,000 scale maps of pertinent elements have been included in this report. Also included are maps showing results of multivariate statistical analyses. Information on the field and analytical procedures used by the Los Alamos National Laboratory during sample collection and analysis may be found in any HSSR data release prepared by the Laboratory and will not be included in this report.

  5. Element geochemical analysis of the contribution of aeolian sand to suspended sediment in desert stream flash floods.

    Science.gov (United States)

    Jia, Xiaopeng; Wang, Haibing

    2014-01-01

    The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream.

  6. Element Geochemical Analysis of the Contribution of Aeolian Sand to Suspended Sediment in Desert Stream Flash Floods

    Directory of Open Access Journals (Sweden)

    Xiaopeng Jia

    2014-01-01

    Full Text Available The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream.

  7. Processes and rates of sediment and wood accumulation in headwater streams of the Oregon Coast Range, USA

    Science.gov (United States)

    May, Christine L.; Gresswell, Robert E.

    2003-01-01

    Channels that have been scoured to bedrock by debris flows provide unique opportunities to calculate the rate of sediment and wood accumulation in low-order streams, to understand the temporal succession of channel morphology following disturbance, and to make inferences about processes associated with input and transport of sediment. Dendrochronology was used to estimate the time since the previous debris flow and the time since the last stand-replacement fire in unlogged basins in the central Coast Range of Oregon. Debris flow activity increased 42 per cent above the background rate in the decades immediately following the last wildfire. Changes in wood and sediment storage were quantified for 13 streams that ranged from 4 to 144 years since the previous debris flow. The volume of wood and sediment in the channel, and the length of channel with exposed bedrock, were strongly correlated with the time since the previous debris flow. Wood increased the storage capacity of the channel and trapped the majority of the sediment in these steep headwater streams. In the absence of wood, channels that have been scoured to bedrock by a debris flow may lack the capacity to store sediment and could persist in a bedrock state for an extended period of time. With an adequate supply of wood, low-order channels have the potential of storing large volumes of sediment in the interval between debris flows and can function as one of the dominant storage reservoirs for sediment in mountainous terrain.

  8. Impact of climate change and anthropogenic activities on stream flow and sediment discharge in the Wei River basin, China

    Directory of Open Access Journals (Sweden)

    P. Gao

    2013-03-01

    Full Text Available Reduced stream flow and increased sediment discharge are a major concern in the Yellow River basin of China, which supplies water for agriculture, industry and the growing populations located along the river. Similar concerns exist in the Wei River basin, which is the largest tributary of the Yellow River basin and comprises the highly eroded Loess Plateau. Better understanding of the drivers of stream flow and sediment discharge dynamics in the Wei River basin is needed for development of effective management strategies for the region and entire Yellow River basin. In this regard we analysed long-term trends for water and sediment discharge during the flood season in the Wei River basin, China. Stream flow and sediment discharge data for 1932 to 2008 from existing hydrological stations located in two subcatchments and at two points in the Wei River were analysed. Precipitation and air temperature data were analysed from corresponding meteorological stations. We identified change-points or transition years for the trends by the Pettitt method and, using double mass curves, we diagnosed whether they were caused by precipitation changes, human intervention, or both. We found significant decreasing trends for stream flow and sediment discharge during the flood season in both subcatchments and in the Wei River itself. Change-point analyses further revealed that transition years existed and that rapid decline in stream flow began in 1968 (P P P P P < 0.05, respectively. The impact of precipitation or human activity on the reduction amount after the transition years was estimated by double mass curves of precipitation vs. stream flow (sediment. For reductions in stream flow and sediment discharge, the contribution rate of human activity was found to be 82.80 and 95.56%, respectively, and was significantly stronger than the contribution rate of precipitation. This evidence clearly suggests that, in the absence of significant decreases in precipitation

  9. Occurrence and potential toxicity of pyrethroids and other insecticides in bed sediments of urban streams in central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hintzen, Emily P. [Department of Environmental Studies, Baylor University, Waco, TX 76798 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center, and Department of Zoology, Southern Illinois University, Carbondale, IL 62091 (United States); Belden, Jason B. [Department of Zoology, Oklahoma State University, 430 Life Science West, Stillwater, OK 74078 (United States)], E-mail: jbelden@okstate.edu

    2009-01-15

    Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings. - This study examined the presence of insecticides in Texas stream sediments as a model for evaluating the potential impact of urban insecticide use in the Southern United States.

  10. Assessment of pathogen levels in stream water column and bed sediment of Merced River Watershed in California

    Science.gov (United States)

    Vaddella, V. K.; Pandey, P.; Biswas, S.; Lewis, D. J.

    2014-12-01

    Mitigating pathogen levels in surface water is crucial for protecting public health. According to the U.S. Environmental Protection Agency (US EPA), approximately 480,000 km of rivers/streams are contaminated in the U.S., and a major cause of contamination is elevated levels of pathogen/pathogen indicator. Many of past studies showed considerably higher pathogen levels in sediment bed than that of the stream water column in rivers. In order to improve the understanding of pathogen levels in rivers in California, we carried out an extensive pathogen monitoring study in four different watersheds (Bear Creek, Ingalsbe, Maxwell, and Yosemite watersheds) of Merced River. Stream water and streambed sediment samples were collected from 17 locations. Pathogen levels (E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were enumerated in streambed sediment and water column. In addition, the impacts of heat stress on pathogen survival were assessed by inoculating pathogens into the water and sediment samples for understanding the pathogen survival in stream water column and streambed sediment. The pathogen enumeration (in water column and sediment bed) results indicated that the E. coli O157:H7, Salmonella spp. and Listeria monocytogenes levels were non-detectable in the water column and streambed sediment. The results of heat stress (50◦ C for 180 minutes) test indicated a pathogen decay at one order of magnitude (108 cfu/ml to 107 cfu/ml). Nonetheless, higher pathogen levels (1.13 × 107 cfu/ml) after the heat stress study showed potential pathogen survival at higher temperature. Preliminary results of this study would help in understanding the impacts of elevated temperature on pathogen in stream environment. Further studies are required to test the long-term heat-stress impacts on pathogen survival.

  11. Biodegradation of 17β-estradiol, estrone, and testosterone in stream sediments

    Science.gov (United States)

    Bradley, P.M.; Chapelle, F.H.; Barber, L.B.; McMahon, P.B.; Gray, J.L.; Kolpin, D.W.

    2009-01-01

    The release of endocrine-disrupting chemicals (EDCs) in wastewater treatment plant (WWTP) effluent poses a significant threat to the ecology of surface water receptors, due to impacts on the hormonal control, sexual development, reproductive success and community structure of the indigenous aquatic organisms and associated wildlife. Among the EDCs commonly observed in WWTP effluent, the natural [e.g., 17??-estradiol (E2) and estrone (E1)] and synthetic [e.g., ethynylestradiol (EE2)] estrogens are particular concerns owing to their high endocrine reactivity in both in vitro and in vivo laboratory models. These reproductive hormones have been identified as the primary cause of estrogenic effects in wastewater effluent, with greater than 95% of the estrogen receptor agonist activity in effluent attributed to this contaminant group. The potentials for in situ biodegradation of 17??-estradiol (E2), estrone (E1), and testosterone (T) were investigated in three, hydrologically-distinct, WWTP-impacted streams in the United States. Relative differences in the mineralization of [4-14C] substrates were assessed in oxic microcosms containing sediment or water-only from locations upstream and downstream of the WWTP outfall in each system. Upstream samples provided insight into the biodegradative potential of sediment microbial communities that were not under the immediate impact of WWTP effluent. Upstream sediment from all three systems demonstrated significant mineralization of the "A" ring of E2, E1 and T, with the potential of T biodegradation consistently greater than of E2 and no systematic difference in the potentials of E2 and E1. Downstream samples provided insight into the impacts of effluent on reproductive hormone biodegradation. Significant "A" ring mineralization was also observed in downstream sediment, with the potentials for E1 and T mineralization being substantially depressed relative to upstream samples. In marked contrast, the potentials for E2

  12. An Evaluation of Microbial Community Structure and Function in Mercury Contaminated Stream Sediments

    Science.gov (United States)

    Palumbo, A. V.; Brown, S. D.; Vishnivestskaya, T. A.; Drake, M.; Kerley, M. K.; Brooks, S. C.; Fagan, L. A.; Gu, B.; Rodriquez, M.; Brandt, C. C.

    2008-12-01

    Although, there has been extensive work on the presence of mercury resistance genes in mercury contaminated environments, there is a relative lack of information on the total bacterial community in highly contaminated mercury sediments. Streams draining DOE facilities in Oak Ridge, TN, have been exposed to discharges of mercury and we are examining the response of streambed microbial communities to this exposure across a Hg contamination gradient using a functional gene array (FGA) and by phylogenetic characterization (a 16s rDNA approach). The version of the FGA used for this study contains 23,864 probes covering 14,000 known microbial functional genes. We hypothesized that there would be a greater diversity of genes related to pollutants at the contaminated sites. In repeated sampling at 2-6 sites, there was a notable response in the FGA results that appears to be related to seasonal changes. We observed low numbers of genes in all categories at all sites during the winter months. Results from warmer months indicate greater differences among sites. In general, during the warmer months the contaminated sites (e.g., mercury at 33.3 ug/g and numerous other contaminants) exhibited elevated gene frequencies in all general categories compared to the control site (e.g., mercury at 0.065 ug/g). In addition to the genes that could be associated with a response to contaminants (e.g., metal resistance and contaminant degradation), genes involved in metabolism (sulfate reduction, denitrification, carbon utilization) were also elevated at the contaminated sites. We also observed an elevation in the number of different rubisco genes present with a much higher number at the most highly contaminated site compared to the control site. The only two currently completed 16s clone libraries are from these sites and interestingly the proportion of cyanobacteria is much higher in the clone library from the contaminated site. Also, the 16s diversity evident in the contaminated site is

  13. Global Positioning System (GPS) and Geographic Information System (GIS) analysis of mobile harvesting equipment and sediment delivery to streams during forest harvest operations on steep terrain: Experimental design

    Science.gov (United States)

    Daniel Bowker; Jeff Stringer; Chris Barton; Songlin. Fei

    2011-01-01

    Sediment mobilized by forest harvest machine traffic contributes substantially to the degradation of headwater stream systems. This study monitored forest harvest machine traffic to analyze how it affects sediment delivery to stream channels. Harvest machines were outfitted with global positioning system (GPS) dataloggers, recording machine movements and working status...

  14. Hydrogeochemical and stream sediment reconnaissance basic data report for Kingman NTMS Quadrangle, Arizona, California, and Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Qualheim, B.J.

    1978-07-01

    This report presents the results of the geochemical reconnaissance sampling in the Kingman 1 x 2 quadrangle of the National Topographical Map Series (NTMS). Wet and dry sediment samples were collected throughout the 18,770-km arid to semiarid area and water samples at available streams, springs, and wells. Neutron activation analysis of uranium and trace elements and other measurements made in the field and laboratory are presented in tabular hardcopy and microfiche format. The report includes five full-size overlays for use with the Kingman NTMS 1 : 250,000 quadrangle. Water sampling sites, water sample uranium concentrations, water-sample conductivity, sediment sampling sites, and sediment-sample total uranium and thorium concentrations are shown on the separate overlays. General geological and structural descriptions of the area are included and known uranium occurrences on this quadrangle are delineated. Results of the reconnaissance are briefly discussed and related to rock types in the final section of the report. The results are suggestive of uranium mineralization in only two areas: the Cerbat Mountains and near some of the western intrusives.

  15. Distributions, abundances and activities of microbes associated with the nitrogen cycle in riparian and stream sediments of a river tributary.

    Science.gov (United States)

    Kim, Haryun; Bae, Hee-Sung; Reddy, K Ramesh; Ogram, Andrew

    2016-12-01

    River tributaries are ecologically important environments that function as sinks of inorganic nitrogen. To gain greater insight into the nitrogen cycle (N-cycle) in these environments, the distributions and activities of microbial populations involved in the N-cycle were studied in riparian and stream sediments of the Santa Fe River (SFR) tributaries located in northern Florida, USA. Riparian sediments were characterized by much higher organic matter content, and extracellular enzyme activities, including cellobiohydrolase, β-d-glucosidase, and phenol oxidase than stream sediments. Compared with stream sediments, riparian sediments exhibited significantly higher activities of nitrification, denitrification, dissimilatory nitrate reduction to ammonia (DNRA) and anaerobic ammonia oxidation; correspondingly, with higher copies of amoA (a biomarker for enumerating nitrifiers), nirS and nirK (for denitrifiers), and nrfA (for DNRA bacteria). Among N-cycle processes, denitrification showed the highest activities and the highest concentrations of the corresponding gene (nirK and nirS) copy numbers. In riparian sediments, substantial nitrification activities (6.3 mg-N kg soil-1d-1 average) and numbers of amoA copies (7.3 × 107 copies g soil-1 average) were observed, and nitrification rates correlate with denitrification rates. The guild structures of denitrifiers and nitrifiers in riparian sediments differed significantly from those found in stream sediments, as revealed by analysis of nirS and archaeal amoA sequences. This study shows that riparian sediments serve as sinks for inorganic nitrogen loads from non-point sources of agricultural runoff, with nitrification and denitrification associated with elevated levels of carbon and nitrogen contents and extracellular enzyme activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    Directory of Open Access Journals (Sweden)

    Bob Laarhoven

    Full Text Available An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv. The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml, 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin. With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

  17. Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

    Science.gov (United States)

    Laarhoven, Bob; Elissen, H J H; Temmink, H; Buisman, C J N

    2016-01-01

    An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

  18. Impact of climate change and anthropogenic activities on stream flow and sediment discharge in the Wei River basin, China

    NARCIS (Netherlands)

    Gao, P.; Geissen, V.; Ritsema, C.J.; Mu, X.M.; Wang, F.

    2013-01-01

    Reduced stream flow and increased sediment discharge are a major concern in the Yellow River basin of China, which supplies water for agriculture, industry and the growing populations located along the river. Similar concerns exist in the Wei River basin, which is the largest tributary of the Yellow

  19. The dark side of the hyporheic zone: Depth profiles of nitrogen and its processing in stream sediments

    Science.gov (United States)

    Stelzer, R.S.; Bartsch, L.A.; Richardson, W.B.; Strauss, E.A.

    2011-01-01

    1.Although it is well known that sediments can be hot spots for nitrogen transformation in streams, many previous studies have confined measurements of denitrification and nitrate retention to shallow sediments (ground water upwelled through shallow sediments before discharging to the stream channel. The results of a two-source mixing model based on chloride concentrations suggested that the hyporheic zone was very shallow (ground water was about 10-60% of the nitrate concentration of deep ground water. The mean nitrate concentrations of deep and shallow ground water were 2.17 and 0.73mgNO3-NL-1, respectively. 5.Deep ground water tended to be oxic (6.9mgO2L-1) but approached anoxia (0.8mgO2L-1) after passing through shallow, organic carbon-rich sediments, which suggests that the decline in the nitrate concentrations of upwelling ground water was because of denitrification. 6.Collectively, our results suggest that there is substantial nitrate removal occurring in deep sediments, below the hyporheic zone, in Emmons Creek. Our findings suggest that not accounting for nitrate removal in deep sediments could lead to underestimates of nitrogen processing in streams and catchments. ?? 2011 Blackwell Publishing Ltd.

  20. StreamCat

    Data.gov (United States)

    U.S. Environmental Protection Agency — The StreamCat Dataset provides summaries of natural and anthropogenic landscape features for ~2.65 million streams, and their associated catchments, within the...

  1. Prioritized Contact Transport Stream

    Science.gov (United States)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  2. Invertebrate colonization of leaves and roots within sediments of intermittent coastal plain streams across hydrologic phases

    Science.gov (United States)

    We compared benthic invertebrate assemblages colonizing three types of buried substrates (leaves, roots and plastic roots) among three intermittent Coastal Plain streams over a one year period. Invertebrate density was significantly lower in root litterbags than in plastic root l...

  3. Multiple stressors in agricultural streams: a mesocosm study of interactions among raised water temperature, sediment addition and nutrient enrichment.

    Directory of Open Access Journals (Sweden)

    Jeremy J Piggott

    Full Text Available Changes to land use affect streams through nutrient enrichment, increased inputs of sediment and, where riparian vegetation has been removed, raised water temperature. We manipulated all three stressors in experimental streamside channels for 30 days and determined the individual and pair-wise combined effects on benthic invertebrate and algal communities and on leaf decay, a measure of ecosystem functioning. We added nutrients (phosphorus+nitrogen; high, intermediate, natural and/or sediment (grain size 0.2 mm; high, intermediate, natural to 18 channels supplied with water from a nearby stream. Temperature was increased by 1.4°C in half the channels, simulating the loss of upstream and adjacent riparian shade. Sediment affected 93% of all biological response variables (either as an individual effect or via an interaction with another stressor generally in a negative manner, while nutrient enrichment affected 59% (mostly positive and raised temperature 59% (mostly positive. More of the algal components of the community responded to stressors acting individually than did invertebrate components, whereas pair-wise stressor interactions were more common in the invertebrate community. Stressors interacted often and in a complex manner, with interactions between sediment and temperature most common. Thus, the negative impact of high sediment on taxon richness of both algae and invertebrates was stronger at raised temperature, further reducing biodiversity. In addition, the decay rate of leaf material (strength loss accelerated with nutrient enrichment at ambient but not at raised temperature. A key implication of our findings for resource managers is that the removal of riparian shading from streams already subjected to high sediment inputs, or land-use changes that increase erosion or nutrient runoff in a landscape without riparian buffers, may have unexpected effects on stream health. We highlight the likely importance of intact or restored buffer

  4. Multiple stressors in agricultural streams: a mesocosm study of interactions among raised water temperature, sediment addition and nutrient enrichment.

    Science.gov (United States)

    Piggott, Jeremy J; Lange, Katharina; Townsend, Colin R; Matthaei, Christoph D

    2012-01-01

    Changes to land use affect streams through nutrient enrichment, increased inputs of sediment and, where riparian vegetation has been removed, raised water temperature. We manipulated all three stressors in experimental streamside channels for 30 days and determined the individual and pair-wise combined effects on benthic invertebrate and algal communities and on leaf decay, a measure of ecosystem functioning. We added nutrients (phosphorus+nitrogen; high, intermediate, natural) and/or sediment (grain size 0.2 mm; high, intermediate, natural) to 18 channels supplied with water from a nearby stream. Temperature was increased by 1.4°C in half the channels, simulating the loss of upstream and adjacent riparian shade. Sediment affected 93% of all biological response variables (either as an individual effect or via an interaction with another stressor) generally in a negative manner, while nutrient enrichment affected 59% (mostly positive) and raised temperature 59% (mostly positive). More of the algal components of the community responded to stressors acting individually than did invertebrate components, whereas pair-wise stressor interactions were more common in the invertebrate community. Stressors interacted often and in a complex manner, with interactions between sediment and temperature most common. Thus, the negative impact of high sediment on taxon richness of both algae and invertebrates was stronger at raised temperature, further reducing biodiversity. In addition, the decay rate of leaf material (strength loss) accelerated with nutrient enrichment at ambient but not at raised temperature. A key implication of our findings for resource managers is that the removal of riparian shading from streams already subjected to high sediment inputs, or land-use changes that increase erosion or nutrient runoff in a landscape without riparian buffers, may have unexpected effects on stream health. We highlight the likely importance of intact or restored buffer strips, both

  5. Productivity of Stream Definitions

    NARCIS (Netherlands)

    Endrullis, J.; Grabmayer, C.A.; Hendriks, R.D.A.; Ishihara, A.; Klop, J.W.

    2010-01-01

    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called 'productive' if it can be evaluated continually in such a way that a uniquely determined stream in constructor normal form is obtained as the limit. Whereas

  6. Productivity of Stream Definitions

    NARCIS (Netherlands)

    Endrullis, Jörg; Grabmayer, Clemens; Hendriks, Dimitri; Isihara, Ariya; Klop, Jan

    2007-01-01

    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called ‘productive’ if it can be evaluated continuously in such a way that a uniquely determined stream is obtained as the limit. Whereas productivity is undecidable

  7. Productivity of stream definitions

    NARCIS (Netherlands)

    Endrullis, J.; Grabmayer, C.A.; Hendriks, D.; Isihara, A.; Klop, J.W.

    2008-01-01

    We give an algorithm for deciding productivity of a large and natural class of recursive stream definitions. A stream definition is called ‘productive’ if it can be evaluated continually in such a way that a uniquely determined stream in constructor normal form is obtained as the limit. Whereas

  8. Sources and ages of fine-grained sediment to streams using fallout radionuclides in the Midwestern United States

    Science.gov (United States)

    Gellis, Allen; Fuller, Christopher C.; Van Metre, Peter C.

    2017-01-01

    Fallout radionuclides, 7Be and 210Pbex, sampled in bed sediment for 99 watersheds in the Midwestern region of the United States and in 15 samples of suspended sediment from 3 of these watersheds were used to partition upland from channel sources and to estimate the age or the time since the surface-derived portion of sediment was on the land surface (0–∼1 year). Channel sources dominate: 78 of the 99 bed material sites (79%) have >50% channel-derived sediment, and 9 of the 15 suspended-sediment samples (60%) have >50% channel-derived sediment. 7Be was detected in 82 bed sediment samples and all 15 suspended-sediment samples. The surface-derived portion of 54 of the 80 (68%) streams with detectable 7Be and 210Pbex were ≤ 100 days old and the surface-derived portion of all suspended-sediment samples were ≤ 100 days old, indicating that surface-derived fine-grained sediment moves rapidly though these systems. The concentrations of two hydrophobic pesticides–DDE and bifenthrin–are correlated with the proportion of surface-derived sediment, indicating a link between geomorphic processes and particle-associated contaminants in streams. Urban areas had the highest pesticide concentrations and the largest percentage of surface-derived sediment. Although the percentage of surface-derived sediment is less than channel sources at most of the study sites, the relatively young age of the surface-derived sediment might indicate that management actions to reduce sediment contamination where the land surface is an important source could have noticeable effects.

  9. Landscape geomorphic characteristic impacts on greenhouse gas fluxes in exposed stream and riparian sediments.

    Science.gov (United States)

    Vidon, Philippe; Serchan, Satish

    2016-07-13

    While excessive releases of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere due to the burning of fossil fuel remains a concern, we also need to better quantify GHG emissions from natural systems. This study investigates GHG fluxes at the soil-atmosphere interface in a series of 7 stream reaches (riparian zones + exposed streambed sediment) across a range of geomorphic locations from headwaters reaches to lowland wetland reaches. When riparian fluxes (RZ) are compared to fluxes from in-stream locations (IS) under summer baseflow conditions, total CO2-equivalent (CO2eq) emissions are approximately 5 times higher at RZ locations than at IS locations, with most CO2eq driven by CH4 production at RZ locations where wet conditions dominate (headwater wetlands, lowland wetlands). On a gas-by-gas basis, no clear differences in N2O fluxes between RZ and IS locations were observed regardless of locations (headwater vs. lowland reaches), while CO2 fluxes were significantly larger at RZ locations than IS locations. Methane fluxes were significantly higher in wetland-influenced reaches than other reaches for both RZ and IS locations. However, GHG fluxes were not consistently correlated to DOC, DO, NO3(-), NH4(+), or water temperature, stressing the limitations of using water quality parameters to predict GHG emissions at the floodplain scale, at least during summer baseflow conditions. As strategies are developed to further constrain GHG emission for whole watersheds, we propose that approaches linking landscape geomorphic characteristics to GHG fluxes at the soil-atmosphere interface offer a promising avenue to successfully predict GHG emissions in floodplains at the watershed scale.

  10. A Microbial Community in Sediments Beneath the Western Antarctic Ice Sheet, Ice Stream C (Kamb)

    Science.gov (United States)

    Skidmore, M.; Han, S.; Foo, W.; Bui, D.; Lanoil, B.

    2004-12-01

    In 2000, an ice-drilling project focusing on the "sticky spot" of Ice Stream C recovered cores of sub-glacial sediments from beneath the Western Antarctic Ice Sheet. We have characterized several chemical and microbiological parameters of the sole intact sediment core. Pore waters extracted from these sediments were brackish and some were supersaturated with respect to calcite. Ion chromatography demonstrated the presence of several organic acids at low, but detectable, levels in the pore water. DAPI direct cell counts were approximately 107 cells g-1. Aerobic viable plate counts were much lower than direct cell counts; however, they were two orders of magnitude higher on plates incubated at low temperature (4 ° C; 3.63 x 105 CFU ml-1) than at higher temperatures (ca. 22° C; 1.5 x 103 CFU ml-1); no colonies were detected on plates incubated anaerobically at either temperature. 16S rDNA clone library analysis indicates extremely limited bacterial diversity in these samples: six phylogenetic clades were detected. The three dominant bacterial phylogenetic clades in the clone libraries (252 clones total) were most closely related to Thiobacillus thioparus (180 clones), Polaromonas vacuolata (34 clones), and Gallionella ferruginea (35 clones) and their relatives; one clone each represented the other three phylogenetic clades (most closely related to Ralstonia pickettii, Lysobacter antibioticus, and Xylella fastidiosa, respectively). These sequences match closely with sequences previously obtained from other subglacial environments in Alaska, Ellesmere Island, Canada and New Zealand. Implications of this microbial community to subglacial chemistry and microbial biogeography will be discussed.

  11. Assessment of stream bottom sediment quality in the vicinity of the Caldas uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Priscila E.S. de, E-mail: pge_13@hotmail.com [Universidade Federal de Ouro Preto (ProAmb/UFOP), Ouro Preto, MG (Brazil). Programa de Pos-Graduacao em Engenharia Ambiental; Filho, Carlos A.C.; Moreira, Rubens M.; Ramos, Maria E.A.F.; Dutra, Pedro H.; Ferreira, Vinicius V.M., E-mail: cacf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte (Brazil); Silva, Nivaldo C., E-mail: ncsilva@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2015-07-01

    An evaluation of the quality of stream bottom sediments was performed in the surroundings of the Caldas Uranium Mining and Milling Facilities (UMMF), sited on Pocos de Caldas Plateau (southeastern Brazil), to verify whether the sediments in the water bodies downstream the plant, were impacted by effluents from a large waste rock pile, named Waste Rock Pile 4 (WRP4), and from the Tailings Dam (TD). In order to perform the research, twelve sampling stations were established in the watersheds around Caldas UMMF: the Soberbo creek, the Consulta brook, and the Taquari river. One of the stations was located inside the Bacia Nestor Figueiredo, a retention pond that receives effluents from WRP4, and another in a settling tank (D2) for radium, which receives the effluents from TD. A monitoring scheme has been developed, comprising four sampling campaigns in 2010 and 2011, and the samples were analyzed for selected metals-metalloids and radionuclides, using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), Ultraviolet-Visible (UV-Vis) Spectroscopy and Gamma-ray Spectrometry. The results suggest that effluents discharged from retention ponds to watercourses, causing an increase in the concentration of As, B, Ba, Cr, Mo, Mn, Pb, Zn, {sup 238}U, {sup 232}Th, {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in sediments. Detailed investigation in sub-superficial layers is recommended at these locations to evaluate the need of implementing mitigation actions such as lining and constructing hydraulic barriers downstream the ponds. Actually, the UTM/Caldas operator is already implementing control measures. (author)

  12. Stream hydrology: an introduction for ecologists

    National Research Council Canada - National Science Library

    2004-01-01

    The updated chapters in this book provide information on sampling, field techniques, stream analysis, the hydrodynamics of moving water, channel form, sediment transport and commonly used statistical...

  13. Hydrologic Connectivity and Land Use Effects on Sediment Accumulation on Stream Floodplains of the Savannah River Site, South Carolina.

    Science.gov (United States)

    Eddy, J.; Yeager, K. M.; Barton, C.; Phillips, J. D.

    2016-12-01

    Natural sediment accumulation on floodplains is important to maintain water quality of streams, to support regional biodiversity as an ecotone between aquatic and terrestrial environments, and to serve as a sink for organic and inorganic carbon. Recent research suggests that land use and hydrologic connectivity play important roles in determining rates of sediment accumulation. This study hypothesizes that changes in hydrologic connectivity have a greater impact on sediment accumulation rates than changes in land use. Nine sediment cores from seven sub-basins were taken from the Savannah River Site, South Carolina, and processed for grain-size, radioisotope dating, particulate organic carbon (POC), and microscopy. Stratigraphic columns were created for all nine cores. Extensive historical records, aerial, and satellite imagery are used to identify anthropogenic disturbances which may have influenced rates of sediment accumulation, as well as to calculate the percentage of natural vegetation in 1951 and 2014. Grain-size analysis and microscopy indicate that the majority of sediment studied is sand-sized quartz; changes in grain-size classification is used to indicate potential differences in sediment sources. LiDAR and field survey data were used to identify 251 stream flow impediments that potentially affect hydrologic connectivity. Results from radioisotope dating and POC have been used to calculate sediment mass accumulation rates (SMAR; g cm-2 y-1) and linear accumulation rates (LAR; cm y-1) for each of the cores. Preliminary findings show that plots of SMAR versus the number of flow impediments have steeper slopes than plots of SMAR versus the percent difference in vegetation (from 1951 to 2014). This signifies that flow impediments, as a proxy for hydrologic connectivity, have a stronger effect on sediment accumulation rates than changes in land use. This knowledge can help future stream restoration efforts by focusing resources to more efficiently attain

  14. Sediment Yield From First Order Streams in Managed Redwood Forests: Effects of Recent Harvests and Legacy Management Practices

    Science.gov (United States)

    Perry, H.; O'Connor, M.; McDavitt, W.

    2003-12-01

    First order streams in the Van Duzen River and lower Eel River watersheds owned by Pacific Lumber Company (Palco) in Humboldt County, California, were surveyed and small sedimentation basins were installed to develop quantitative estimates of sediment yield. A random study design was developed to investigate the potential effects of different geologic substrates and forest management on sediment yield. The drainage area for these streams was about 5 to 10 ha where fluvial characteristics were expressed. The erosion processes within the scope of this investigation included surface erosion from hillslopes and harvest units, rill and gully erosion that may occur in relation to skid trails (recently used or abandoned), and stream channel erosion, including bank erosion and small-scale mass wasting. Temporary sedimentation basins were installed in 30 randomly chosen channels to quantify relative amounts of sediment yield from watersheds with different management conditions (treatment sites) and second-growth stands not recently entered (control sites). Most treatment sites were clearcut harvests. Two classes of treated sites were sampled: sites harvested under stricter regulations of a Habitat Conservation Plan (HCP) and sites harvested prior to implementation of the HCP. Channel surveys were also conducted to characterize conditions and identify existing evidence of channel erosion and surface erosion in areas adjacent to the channel. Results from winter 2001/02 suggested that there may be differences in sediment yield among geologic substrates, with the Wildcat having relatively low sediment yield values. Treatment effects were significantly different (ANOVA, p effect on sediment yield may be influenced by the fact that the HCP treatment sites have experienced only one or two post-harvest winters, while the pre-HCP treatment sites experienced relatively severe winters over a longer post-harvest period. In addition, the fact that the control sites tended to have higher

  15. Patterns and contributions of floodplain and legacy sediments remobilized from Piedmont streams of the mid-Atlantic U.S.

    Science.gov (United States)

    Donovan, Mitchell; Miller, Andrew; Baker, Matthew; Gellis, Allen

    2015-04-01

    The perceived role of streambank erosion as a contributor to watershed sediment yield is an important driver of policy decisions for managing downstream impacts in the United States. In the Piedmont physiographic province of the eastern U.S. and in other regions of the south and midwest, the issue of 'legacy' sediment stored in stream valleys has long been recognized as a consequence of rapid deforestation and erosive agricultural practices following European settlement. Remobilization of stored floodplain sediment by bank erosion is frequently cited as a dominant component of watershed sediment budgets, with legacy sediment comprising the largest portion of this source. However there are few published studies documenting spatially extensive measurements of channel change throughout the drainage network on time scales of more than a few years. In this study we document 1) rates of sediment remobilization from Baltimore County floodplains by channel migration and bank erosion, 2) proportions of streambank sediment derived from legacy deposits, and 3) potential contribution of net streambank erosion and legacy sediments to downstream sediment yield within the Mid-Atlantic Piedmont. We measured gross erosion and channel deposition rates over 45 years within the fluvial corridor along 40 valley segments from 18 watersheds with drainage areas between 0.18 and 155 km2 by comparing stream channel and floodplain morphology from LiDAR-based digital elevation data collected in 2005 with channel positions recorded on 1:2400-scale topographic maps from 1959-1961. Results were extrapolated to estimate contributions to watershed sediment yield from 1005 km2 of northern Baltimore County. Results indicate that legacy sediment is a dominant component (62%) of the sediment derived from bank erosion and that its relative importance is greater in larger valleys with broader valley floors and lower gradients. Although mass of sediment remobilized per unit channel length is greater in

  16. Benthic invertebrate fauna, small streams

    Science.gov (United States)

    J. Bruce Wallace; S.L. Eggert

    2009-01-01

    Small streams (first- through third-order streams) make up >98% of the total number of stream segments and >86% of stream length in many drainage networks. Small streams occur over a wide array of climates, geology, and biomes, which influence temperature, hydrologic regimes, water chemistry, light, substrate, stream permanence, a basin's terrestrial plant...

  17. Chemical data and lead isotopic compositions in stream-sediment samples from the Boulder River watershed, Jefferson County, Montana

    Science.gov (United States)

    Fey, David L.; Unruh, Dan M.; Church, Stan E.

    1999-01-01

    Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana, have been evaluated for their environmental effects as a part of the U.S. Geological Survey Abandoned Mine Lands Project. Many mine and prospect waste dumps, and mill wastes are located in the drainage basins of Basin Creek, Cataract Creek, and High Ore Creek, the three major tributaries to the Boulder River in the study area. Throughout the study area, mine-waste material has been transported into and down streams, where it mixes with and becomes incorporated into the bed sediments. In some locations, waste material was placed by mine operators directly in stream channels, and has been transported downstream forming fluvial tailings deposits along the stream banks. Water quality and aquatic habitat have been affected by acid generation and toxic-metal mobility during snowmelt and storm water runoff events. Colloids formed by the raising of pH downstream from these mine sites sorb metals contributing to the high concentrations observed in both bed and suspended sediments within the watershed. This report presents geochemical data for bed sediments from 67 sites and lead isotope data for 59 sites. Also included are geochemical data for seven suspended-sediment samples, and one smelter slag sample. 

  18. Genes indicative of zoonotic and swine pathogens are persistent in stream water and sediment following a swine manure spill

    Science.gov (United States)

    Haack, Sheridan K.; Duris, Joseph W.; Kolpin, Dana W.; Fogarty, Lisa R.; Johnson, Heather E.; Gibson, Kristen E.; Focazio, Michael J.; Schwab, Kellogg J.; Hubbard, Laura E.; Foreman, William T.

    2015-01-01

    Manure spills to streams are relatively frequent, but no studies have characterized stream contamination with zoonotic and veterinary pathogens, or fecal chemicals, following a spill. We tested stream water and sediment over 25 days and downstream for 7.6 km for: fecal indicator bacteria (FIB); the fecal indicator chemicals cholesterol and coprostanol; 20 genes for zoonotic and swine-specific bacterial pathogens by presence/absence polymerase chain reaction (PCR) for viable cells; one swine-specific Escherichia coli toxin gene (STII) by quantitative PCR (qPCR); and nine human and animal viruses by qPCR, or reverse-transcriptase qPCR. Twelve days post-spill, and 4.2 km downstream, water concentrations of FIB, cholesterol, and coprostanol were 1-2 orders of magnitude greater than those detected before, or above, the spill, and genes indicating viable zoonotic or swine-infectious Escherichia coli, were detected in water or sediment. STII increased from undetectable before, or above the spill, to 105 copies/100 mL water 12 days post-spill. Thirteen of 14 water (8/9 sediment) samples had viable STII-carrying cells post-spill. Eighteen days post-spill porcine adenovirus and teschovirus were detected 5.6 km downstream. Sediment FIB concentrations (per gram wet weight) were greater than in water, and sediment was a continuous reservoir of genes and chemicals post-spill. Constituent concentrations were much lower, and detections less frequent, in a runoff event (200 days post-spill) following manure application, although the swine-associated STII and stx2e genes were detected. Manure spills are an underappreciated pathway for livestock-derived contaminants to enter streams, with persistent environmental outcomes, and the potential for human and veterinary health consequences.

  19. Time and depth scales of fine sediment delivery into gravel stream beds: Constraints from fallout radionuclides on fine sediment residence time and delivery

    Science.gov (United States)

    Gartner, J. D.; Renshaw, C. E.; Dade, W. B.; Magilligan, F. J.

    2012-05-01

    Particles of fine sediment can clog interstitial pore spaces of coarser grained sediment in river beds and thereby impede the exchange of water, dissolved constituents, and particulate matter with consequent ecological impacts. The extent to which fine sediment reduces connectivity between the stream bed and overlying channel is a function, in part, of sediment residence time. Short residence times imply frequent exchange of matter and reduced impact of fine sediment on stream bed habitat, while long residence times indicate that with respect to fine sediment delivery, the stream bed is more isolated from the overlying channel. Here we present a novel technique to quantify the residence time of river bed sediment at various depths over annual and decadal timescales using the fallout radionuclides (FRNs) 7Be (t1/2 = 53 days) and 210Pbex (t1/2 = 22.3 years). We placed mesh cylinders filled with 7Be-free sediment into a stream bed to quantify the capture of 7Be-tagged particles in the absence of scour and fill. We also took cores to the depth of refusal in alluvial sediment in unregulated and regulated rivers in Vermont and New Hampshire. Sampled watershed areas ranged from 29 to 410 km2, and core depths ranged from 19 to 77 cm. The 210Pbex activity profiles of cores show that bed sediment is exchanged to the depth of refusal at decadal timescales. In contrast, 7Be activity profiles indicate that fine sediment infiltrating into the bed had residence times ranging from 4 to > 300 days in unregulated rivers. Cores from a regulated river are notably different—subsurface sediment residence times were always longer than in unregulated rivers at comparable depths, likely owing to restriction of bed mobilization and clogging of bed material by fine sediment. These results suggest that filtration can be an important component of bed material delivery to stream beds, but filtration does not deliver material as deeply into the bed as scour and fill. We find that fallout

  20. Pollution of the stream waters and sediments associated with the Crucea uranium mine (East Carpathians, Romania)

    Science.gov (United States)

    Petrescu, L.; Bilal, E.; Iatan, E. L.

    2009-04-01

    Uranium and thorium are omnipresent in our environment. Various anthropogenic activities involving the processing or use of materials rich in uranium may modify the natural abundance of uranium in water. The study is related to uranium mineralization located within Crucea ore deposit, in the East Carpathians, Romania. The Crucea uranium ore deposit is located in the eastern part of the Bistrita Mountains (40 Km southeast of the town of Vatra Dornei) in the headwaters of Crucea, Lesu and Livezi valleys. At present, this is the largest uranium mine in the country. In the past, the mining area covered 18 km2, but was gradually overtaken by logging activities. The exploration and mining facilities include thirty-two galleries, situated between 780 and 1040 m above sea level. Radioactive waste resulted from mining are disposed next to the mining facilities. The waste rock was disposed in piles of variable size that are spread over an area of 364,000 m2. Older dumps (18) have been already naturally reclaimed by forest vegetation. The vegetation cover played an important role in stabilizing the waste dump cover and in slowing down the uranium migration processes. A number of 46 water samples were taken in order to evaluate the impact of ore deposit (including its exploitation process) on the chemical composition of waters down to the exploitation galleries. The sediment samples were collected at 16 sampling points from the bottom of the studied stream waters. ICP-OES, XRF and IC methods was used to evaluate the impact of uranium mine dumps on the surface waters from Crucea region. According to the analytical data the stream waters showed a Ca - carbonate character. In relation to salinity, the pH and the anion NO3-, CO32-and SO42- contents display generally non-linear relationships with chloride. Uranium is the most significant trace element in the river waters nearby the waste rock dumps, sometimes reaching levels up to 1-mgṡL-1, well in excess of the Romanian

  1. Sampling surface and subsurface particle-size distributions in wadable gravel-and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

    Science.gov (United States)

    Kristin Bunte; Steven R. Abt

    2001-01-01

    This document provides guidance for sampling surface and subsurface sediment from wadable gravel-and cobble-bed streams. After a short introduction to streams types and classifications in gravel-bed rivers, the document explains the field and laboratory measurement of particle sizes and the statistical analysis of particle-size distributions. Analysis of particle...

  2. Pathways for arsenic from sediments to groundwater to streams: Biogeochemical processes in the Inner Coastal Plain, New Jersey, USA

    Science.gov (United States)

    Barringer, Julia L.; Mumford, Adam; Young, Lily Y.; Reilly, Pamela A.; Bonin, Jennifer L.; Rosman, Robert

    2010-01-01

    The Cretaceous and Tertiary sediments that underlie the Inner Coastal Plain of New Jersey contain the arsenic-rich mineral glauconite. Streambed sediments in two Inner Coastal Plain streams (Crosswicks and Raccoon Creeks) that traverse these glauconitic deposits are enriched in arsenic (15–25 mg/kg), and groundwater discharging to the streams contains elevated levels of arsenic (>80 μg/L at a site on Crosswicks Creek) with arsenite generally the dominant species. Low dissolved oxygen, low or undetectable levels of nitrate and sulfate, detectable sulfide concentrations, and high concentrations of iron and dissolved organic carbon (DOC) in the groundwater indicate that reducing environments are present beneath the streambeds and that microbial activity, fueled by the DOC, is involved in releasing arsenic and iron from the geologic materials. In groundwater with the highest arsenic concentrations at Crosswicks Creek, arsenic respiratory reductase gene (arrA) indicated the presence of arsenic-reducing microbes. From extracted DNA, 16s rRNA gene sequences indicate the microbial community may include arsenic-reducing bacteria that have not yet been described. Once in the stream, iron is oxidized and precipitates as hydroxide coatings on the sediments. Arsenite also is oxidized and co-precipitates with or is sorbed to the iron hydroxides. Consequently, dissolved arsenic concentrations are lower in streamwater than in the groundwater, but the arsenic contributed by groundwater becomes part of the arsenic load in the stream when sediments are suspended during high flow. A strong positive relation between concentrations of arsenic and DOC in the groundwater samples indicates that any process—natural or anthropogenic—that increases the organic carbon concentration in the groundwater could stimulate microbial activity and thus increase the amount of arsenic that is released from the geologic materials.

  3. Pathways for arsenic from sediments to groundwater to streams: biogeochemical processes in the Inner Coastal Plain, New Jersey, USA.

    Science.gov (United States)

    Barringer, Julia L; Mumford, Adam; Young, Lily Y; Reilly, Pamela A; Bonin, Jennifer L; Rosman, Robert

    2010-11-01

    The Cretaceous and Tertiary sediments that underlie the Inner Coastal Plain of New Jersey contain the arsenic-rich mineral glauconite. Streambed sediments in two Inner Coastal Plain streams (Crosswicks and Raccoon Creeks) that traverse these glauconitic deposits are enriched in arsenic (15-25mg/kg), and groundwater discharging to the streams contains elevated levels of arsenic (>80μg/L at a site on Crosswicks Creek) with arsenite generally the dominant species. Low dissolved oxygen, low or undetectable levels of nitrate and sulfate, detectable sulfide concentrations, and high concentrations of iron and dissolved organic carbon (DOC) in the groundwater indicate that reducing environments are present beneath the streambeds and that microbial activity, fueled by the DOC, is involved in releasing arsenic and iron from the geologic materials. In groundwater with the highest arsenic concentrations at Crosswicks Creek, arsenic respiratory reductase gene (arrA) indicated the presence of arsenic-reducing microbes. From extracted DNA, 16s rRNA gene sequences indicate the microbial community may include arsenic-reducing bacteria that have not yet been described. Once in the stream, iron is oxidized and precipitates as hydroxide coatings on the sediments. Arsenite also is oxidized and co-precipitates with or is sorbed to the iron hydroxides. Consequently, dissolved arsenic concentrations are lower in streamwater than in the groundwater, but the arsenic contributed by groundwater becomes part of the arsenic load in the stream when sediments are suspended during high flow. A strong positive relation between concentrations of arsenic and DOC in the groundwater samples indicates that any process-natural or anthropogenic-that increases the organic carbon concentration in the groundwater could stimulate microbial activity and thus increase the amount of arsenic that is released from the geologic materials. Published by Elsevier Ltd.

  4. Present and Reference Concentrations and Yields of Suspended Sediment in Streams in the Great Lakes Region and Adjacent Areas

    Science.gov (United States)

    Robertson, Dale M.; Saad, David A.; Heisey, Dennis M.

    2006-01-01

    In-stream suspended sediment and siltation and downstream sedimentation are common problems in surface waters throughout the United States. The most effective way to improve surface waters impaired by sediments is to reduce the contributions from human activities rather than try to reduce loadings from natural sources. Total suspended sediment/solids (TSS) concentration data were obtained from 964 streams in the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River Basins from 1951 to 2002. These data were used to estimate median concentrations, loads, yields, and volumetrically (flow) weighted (VW) concentrations where streamflow data were available. SPAtial Regression-Tree Analysis (SPARTA) was applied to land-use-adjusted (residualized) TSS data and environmental-characteristic data to determine the natural factors that best described the distribution of median and VW TSS concentrations and yields and to delineate zones with similar natural factors affecting TSS, enabling reference or natural concentrations and yields to be estimated. Soil properties (clay and organic-matter content, erodibility, and permeability), basin slope, and land use (percentage of agriculture) were the factors most strongly related to the distribution of median and VW TSS concentrations. TSS yields were most strongly related to amount of precipitation and the resulting runoff, and secondarily to the factors related to high TSS concentrations. Reference median TSS concentrations ranged from 5 to 26 milligrams per liter (mg/L), reference median annual VW TSS concentrations ranged from 10 to 168 mg/L, and reference TSS yields ranged from about 980 to 90,000 kilograms per square kilometer per year. Independent streams (streams with no overlapping drainage areas) with TSS data were ranked by how much their water quality exceeded reference concentrations and yields. Most streams exceeding reference conditions were in the central part of the study area, where agricultural activities

  5. Denitrification potential in stream sediments impacted by acid mine drainage: Effects of pH, various electron donors, and iron

    Science.gov (United States)

    Baeseman, J.L.; Smith, R.L.; Silverstein, J.

    2006-01-01

    Acid mine drainage (AMD) contaminates thousands of kilometers of stream in the western United States. At the same time, nitrogen loading to many mountain watersheds is increasing because of atmospheric deposition of nitrate and increased human use. Relatively little is known about nitrogen cycling in acidic, heavy-metal-laden streams; however, it has been reported that one key process, denitrification, is inhibited under low pH conditions. The objective of this research was to investigate the capacity for denitrification in acidified streams. Denitrification potential was assessed in sediments from several Colorado AMD-impacted streams, ranging from pH 2.60 to 4.54, using microcosm incubations with fresh sediment. Added nitrate was immediately reduced to nitrogen gas without a lag period, indicating that denitrification enzymes were expressed and functional in these systems. First-order denitrification potential rate constants varied from 0.046 to 2.964 day-1. The pH of the microcosm water increased between 0.23 and 1.49 pH units during denitrification. Additional microcosm studies were conducted to examine the effects of initial pH, various electron donors, and iron (added as ferrous and ferric iron). Decreasing initial pH decreased denitrification; however, increasing pH had little effect on denitrification rates. The addition of ferric and ferrous iron decreased observed denitrification potential rate constants. The addition of glucose and natural organic matter stimulated denitrification potential. The addition of hydrogen had little effect, however, and denitrification activity in the microcosms decreased after acetate addition. These results suggest that denitrification can occur in AMD streams, and if stimulated within the environment, denitrification might reduce acidity. ?? Springer Science+Business Media, Inc. 2006.

  6. Hydrography - Streams and Shorelines

    Data.gov (United States)

    California Department of Resources — The hydrography layer consists of flowing waters (rivers and streams), standing waters (lakes and ponds), and wetlands -- both natural and manmade. Two separate...

  7. User aware video streaming

    Science.gov (United States)

    Kerofsky, Louis; Jagannath, Abhijith; Reznik, Yuriy

    2015-03-01

    We describe the design of a video streaming system using adaptation to viewing conditions to reduce the bitrate needed for delivery of video content. A visual model is used to determine sufficient resolution needed under various viewing conditions. Sensors on a mobile device estimate properties of the viewing conditions, particularly the distance to the viewer. We leverage the framework of existing adaptive bitrate streaming systems such as HLS, Smooth Streaming or MPEG-DASH. The client rate selection logic is modified to include a sufficient resolution computed using the visual model and the estimated viewing conditions. Our experiments demonstrate significant bitrate savings compare to conventional streaming methods which do not exploit viewing conditions.

  8. The case against streaming

    National Research Council Canada - National Science Library

    Natalia Mironova

    2014-01-01

    .... Cassidy, the safety coordinator at the Airline Pilots Association, says Levine and others advocating for live data streaming are oversimplifying the issue and overlooking the logistical concerns...

  9. Modeling sediment transport from an off-road vehicle trail stream crossing using WEPP model

    Science.gov (United States)

    Renee' D. Ayala; Puneet Srivastava; Christian J. Brodbeck; Emily A. Carter; Timothy P. McDonald

    2005-01-01

    There is a limited information available pertaining to the adverse effects of Off-Road-Vehicle (ORV) use and trail impacts. As a result, this study was initiated in 2003 to (a) quantify water quality impacts of an ORV trail stream crossing through monitoring of total suspended solids, and (b) conduct WEPP (Water Erosion Prediction Project) simulations to determine long...

  10. The application of stream sediment and heavy mineral exploratory methods on evaluation of mineralization potential in Soltan Meydan basalts, north of Shahroud

    National Research Council Canada - National Science Library

    Mehdi Hashemi Gahrouei; Behnam Shafiei; Gholamhossein. Shamanian; Hossein Taghizadeh

    2012-01-01

    In order to assess the potential of copper mineralization and its associated elements in Soltan Meydan basaltic formation situated in the north of Shahrud, the method of stream sediment and heavy mineral has been used...

  11. An inventory of suspended sediment stations and type of data analysis for Pennsylvania streams, 1947-1970

    Science.gov (United States)

    Ott, Arthur N.; Commings, Allen B.

    1972-01-01

    Data concerning suspended sediment concentrations and loads, frequency of occurrence of suspended sediment concentrations, and long-term trends of annual suspended sediment loads are important tools for today's environmental manager. These data are required background for those concerned with establishing and enforcing erosion and sedimentation control regulations and sediment concentration or turbidity standards for water-quality criteria, or those concerned with designing for adequate long-term water storage in reservoirs (sediment load), for efficient municipal and industrial plant operation (sediment concentration frequency), etc.This is a compilation of the location, period of record, sampling frequency and type of data synthesis for suspended sediment carried by Pennsylvania streams. Figures 1 and 2 show the approximate locations of sediment sampling stations in Pennsylvania. All of the sediment data listed were collected by the U. S. Geological Survey mainly in cooperation with the following Federal, State, and local agencies.Pennsylvania Department of Environmental Resources     Bureau of Engineering and Construction     Soil and Water Conservation CommissionPennsylvania Department of TransportationCity of PhiladelphiaBrandywine Valley AssociationDelaware Geological SurveyConestoga Valley AssociationLehigh County Soil and Water Conservation DistrictCorps of Engineers, U. S. Army

  12. Potential risk assessment in stream sediments, soils and waters after remediation in an abandoned W>Sn mine (NE Portugal).

    Science.gov (United States)

    Antunes, I M H R; Gomes, M E P; Neiva, A M R; Carvalho, P C S; Santos, A C T

    2016-11-01

    The mining complex of Murçós belongs to the Terras de Cavaleiros Geopark, located in Trás-os-Montes region, northeast Portugal. A stockwork of NW-SE-trending W>Sn quartz veins intruded Silurian metamorphic rocks and a Variscan biotite granite. The mineralized veins contain mainly quartz, cassiterite, wolframite, scheelite, arsenopyrite, pyrite, sphalerite, chalcopyrite, galena, rare pyrrhotite, stannite, native bismuth and also later bismuthinite, matildite, joseite, roosveltite, anglesite, scorodite, zavaritskite and covellite. The exploitation produced 335t of a concentrate with 70% of W and 150t of another concentrate with 70% of Sn between 1948 and 1976. The exploitation took place mainly in four open pit mines as well as underground. Three lakes were left in the area. Remediation processes of confination and control of tailings and rejected materials and phytoremediation with macrophytes from three lakes were carried out between 2005 and 2007. Stream sediments, soils and water samples were collected in 2008 and 2009, after the remediation process. Most stream sediments showed deficiency or minimum enrichment for metals. The sequential enrichment factor in stream sediments W>Bi>As>U>Cd>Sn=Ag>Cu>Sb>Pb>Be>Zn is mainly associated with the W>Sn mineralizations. Stream sediments receiving drainage of a mine dump were found to be significantly to extremely enriched with W, while stream sediments and soils were found to be contaminated with As. Two soil samples collected around mine dumps and an open pit lake were also found to be contaminated with U. The waters from the Murçós W>Sn mine area were acidic to neutral. After the remediation, the surface waters were contaminated with F(-), Al, As, Mn and Ni and must not be used for human consumption, while open pit lake waters must also not be used for agriculture because of contamination with F(-), Al, Mn and Ni. In most waters, the As occurred as As (III), which is toxic and is easily mobilized in the drainage

  13. Geochemical insights to the formation of "sedimentary buffers": Considering the role of tributary-trunk stream interactions on catchment-scale sediment flux and drainage network dynamics

    Science.gov (United States)

    Fryirs, Kirstie; Gore, Damian B.

    2014-08-01

    The concept of disconnectivity (or decoupling) of sediment movement in river systems is an important concept in analyses of sediment flux in catchments. At the catchment scale, various blockages-termed buffers, barriers and blankets-form along the sediment cascade, interrupting the conveyance of sediments downstream. Long-lived buffers can control aspects of catchment sediment flux for an extended period. The upper Hunter catchment has a highly disconnected sediment cascade. The most highly disconnected subcatchment (Dart Brook) contains a distinct type of buffer, a trapped tributary fill, in its downstream reaches, reducing the effective catchment area of the upper Hunter catchment by ~ 18%. We test the use of elemental analyses provided by X-ray fluorescence (XRF) spectrometry of homogenous sediment profiles taken from floodplain bank exposures to determine that the geochemical composition of the sediments that make up this trapped-tributary fill system have been derived from two distinct source areas (the tributary system and the trunk stream). Over at least the Holocene, sedimentation along the axis of the Hunter River valley (the trunk stream) has formed an impediment to sediment conveyance along the lower tributary catchment, essentially "trapping" the tributary. We present an evolutionary model of how this type of "blockage" has formed and discuss implications of tributary-trunk stream (dis)connectivity in analysis of catchment-scale sediment flux and drainage network dynamics. In this case, a relatively large tributary network is having a "geomorphically insignificant" impact on trunk stream dynamics.

  14. LHCb trigger streams optimization

    Science.gov (United States)

    Derkach, D.; Kazeev, N.; Neychev, R.; Panin, A.; Trofimov, I.; Ustyuzhanin, A.; Vesterinen, M.

    2017-10-01

    The LHCb experiment stores around 1011 collision events per year. A typical physics analysis deals with a final sample of up to 107 events. Event preselection algorithms (lines) are used for data reduction. Since the data are stored in a format that requires sequential access, the lines are grouped into several output file streams, in order to increase the efficiency of user analysis jobs that read these data. The scheme efficiency heavily depends on the stream composition. By putting similar lines together and balancing the stream sizes it is possible to reduce the overhead. We present a method for finding an optimal stream composition. The method is applied to a part of the LHCb data (Turbo stream) on the stage where it is prepared for user physics analysis. This results in an expected improvement of 15% in the speed of user analysis jobs, and will be applied on data to be recorded in 2017.

  15. Buried particulate organic carbon stimulates denitrification and nitrate retention in stream sediments at the groundwater-surface water interface

    Science.gov (United States)

    Stelzer, Robert S.; Scott, J. Thad; Bartsch, Lynn

    2015-01-01

    The interface between ground water and surface water in streams is a hotspot for N processing. However, the role of buried organic C in N transformation at this interface is not well understood, and inferences have been based largely on descriptive studies. Our main objective was to determine how buried particulate organic C (POC) affected denitrification and NO3− retention in the sediments of an upwelling reach in a sand-plains stream in Wisconsin. We manipulated POC in mesocosms inserted in the sediments. Treatments included low and high quantities of conditioned red maple leaves (buried beneath combusted sand), ambient sediment (sand containing background levels of POC), and a control (combusted sand). We measured denitrification rates in sediments by acetylene-block assays in the laboratory and by changes in N2 concentrations in the field using membrane inlet mass spectrometry. We measured NO3−, NH4+, and dissolved organic N (DON) retention as changes in concentrations and fluxes along groundwater flow paths in the mesocosms. POC addition drove oxic ground water to severe hypoxia, led to large increases in dissolved organic C (DOC), and strongly increased denitrification rates and N (NO3− and total dissolved N) retention relative to the control. In situ denitrification accounted for 30 to 60% of NO3− retention. Our results suggest that buried POC stimulated denitrification and NO3− retention by producing DOC and by creating favorable redox conditions for denitrification.

  16. Geochemistry and mineralogy of arsenic in mine wastes and stream sediments in a historic metal mining area in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Rieuwerts, J.S., E-mail: jrieuwerts@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA (United Kingdom); Mighanetara, K.; Braungardt, C.B. [School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA (United Kingdom); Rollinson, G.K. [Camborne School of Mines, CEMPS, University of Exeter, Tremough Campus, Penryn, Cornwall TR10 9EZ (United Kingdom); Pirrie, D. [Helford Geoscience LLP, Menallack Farm, Treverva, Penryn, Cornwall TR10 9BP (United Kingdom); Azizi, F. [School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA (United Kingdom)

    2014-02-01

    Mining generates large amounts of waste which may contain potentially toxic elements (PTE), which, if released into the wider environment, can cause air, water and soil pollution long after mining operations have ceased. The fate and toxicological impact of PTEs are determined by their partitioning and speciation and in this study, the concentrations and mineralogy of arsenic in mine wastes and stream sediments in a former metal mining area of the UK are investigated. Pseudo-total (aqua-regia extractable) arsenic concentrations in all samples from the mining area exceeded background and guideline values by 1–5 orders of magnitude, with a maximum concentration in mine wastes of 1.8 × 10{sup 5} mg kg{sup −1} As and concentrations in stream sediments of up to 2.5 × 10{sup 4} mg kg{sup −1} As, raising concerns over potential environmental impacts. Mineralogical analysis of the wastes and sediments was undertaken by scanning electron microscopy (SEM) and automated SEM-EDS based quantitative evaluation (QEMSCAN®). The main arsenic mineral in the mine waste was scorodite and this was significantly correlated with pseudo-total As concentrations and significantly inversely correlated with potentially mobile arsenic, as estimated from the sum of exchangeable, reducible and oxidisable arsenic fractions obtained from a sequential extraction procedure; these findings correspond with the low solubility of scorodite in acidic mine wastes. The work presented shows that the study area remains grossly polluted by historical mining and processing and illustrates the value of combining mineralogical data with acid and sequential extractions to increase our understanding of potential environmental threats. - Highlights: • Stream sediments in a former mining area remain polluted with up to 25 g As per kg. • The main arsenic mineral in adjacent mine wastes appears to be scorodite. • Low solubility scorodite was inversely correlated with potentially mobile As. • Combining

  17. The Midwest Stream Quality Assessment

    Science.gov (United States)

    ,

    2012-01-01

    In 2013, the U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) and USGS Columbia Environmental Research Center (CERC) will be collaborating with the U.S. Environmental Protection Agency (EPA) National Rivers and Streams Assessment (NRSA) to assess stream quality across the Midwestern United States. The sites selected for this study are a subset of the larger NRSA, implemented by the EPA, States and Tribes to sample flowing waters across the United States (http://water.epa.gov/type/rsl/monitoring/riverssurvey/index.cfm). The goals are to characterize water-quality stressors—contaminants, nutrients, and sediment—and ecological conditions in streams throughout the Midwest and to determine the relative effects of these stressors on aquatic organisms in the streams. Findings will contribute useful information for communities and policymakers by identifying which human and environmental factors are the most critical in controlling stream quality. This collaborative study enhances information provided to the public and policymakers and minimizes costs by leveraging and sharing data gathered under existing programs. In the spring and early summer, NAWQA will sample streams weekly for contaminants, nutrients, and sediment. During the same time period, CERC will test sediment and water samples for toxicity, deploy time-integrating samplers, and measure reproductive effects and biomarkers of contaminant exposure in fish or amphibians. NRSA will sample sites once during the summer to assess ecological and habitat conditions in the streams by collecting data on algal, macroinvertebrate, and fish communities and collecting detailed physical-habitat measurements. Study-team members from all three programs will work in collaboration with USGS Water Science Centers and State agencies on study design, execution of sampling and analysis, and reporting.

  18. Percent Agriculture Adjacent to Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  19. Solute and sediment export from Amazon forest and soybean headwater streams.

    Science.gov (United States)

    Riskin, Shelby H; Neill, Christopher; Jankowski, KathiJo; Krusche, Alex V; McHorney, Richard; Elsenbeer, Helmut; Macedo, Marcia N; Nunes, Darlisson; Porder, Stephen

    2017-01-01

    Intensive cropland agriculture commonly increases streamwater solute concentrations and export from small watersheds. In recent decades, the lowland tropics have become the world's largest and most important region of cropland expansion. Although the effects of intensive cropland agriculture on streamwater chemistry and watershed export have been widely studied in temperate regions, their effects in tropical regions are poorly understood. We sampled seven headwater streams draining watersheds in forest (n = 3) or soybeans (n = 4) to examine the effects of soybean cropping on stream solute concentrations and watershed export in a region of rapid soybean expansion in the Brazilian state of Mato Grosso. We measured stream flows and concentrations of NO3- , PO43- , SO42- , Cl- , NH4+ , Ca2+ , Mg2+ , Na+ , K+ , Al3+ , Fe3+ , and dissolved organic carbon (DOC) biweekly to monthly to determine solute export. We also measured stormflows and stormflow solute concentrations in a subset of watersheds (two forest, two soybean) during two/three storms, and solutes and δ18 O in groundwater, rainwater, and throughfall to characterize watershed flowpaths. Concentrations of all solutes except K+ varied seasonally in streamwater, but only Fe3+ concentrations differed between land uses. The highest streamwater and rainwater solute concentrations occurred during the peak season of wildfires in Mato Grosso, suggesting that regional changes in atmospheric composition and deposition influence seasonal stream solute concentrations. Despite no concentration differences between forest and soybean land uses, annual export of NH4+ , PO43- , Ca2+ , Fe3+ , Na+ , SO42- , DOC, and TSS were significantly higher from soybean than forest watersheds (5.6-fold mean increase). This increase largely reflected a 4.3-fold increase in water export from soybean watersheds. Despite this increase, total solute export per unit watershed area (i.e., yield) remained low for all watersheds (solute

  20. A stream sediment geochemical survey of the Ganga River headwaters in the Garhwal Himalaya

    Science.gov (United States)

    Mukherjee, P.K.; Purohit, K.K.; Saini, N.K.; Khanna, P.P.; Rathi, M.S.; Grosz, A.E.

    2007-01-01

    This study models geochemical and adjunct geologic data to define provinces that are favorable for radioactive-mineral exploration. A multi-element bed-sediment geochemical survey of streams was carried out in the headwaters region of the Ganga River in northern India. Overall median values for uranium and thorium (3.6 and 13.8 ppm; maxima of 4.8 and 19.0 ppm and minima of 3.1 and 12.3 ppm respectively) exceed average upper crustal abundances (2.8 and 10.7 ppm) for these radioactive elements. Anomalously high values reach up to 8.3 and 30.1 ppm in thrust zone rocks, and 11.4 and 22.5 ppm in porphyroids. At their maxima, these abundances are nearly four- and three-fold (respectively) enriched in comparison to average crustal abundances for these rock types. Deformed, metamorphosed and sheared rocks are characteristic of the main central thrust zone (MCTZ). These intensively mylonitized rocks override and juxtapose porphyritic (PH) and proterozoic metasedimentary rock sequences (PMS) to the south. Granitoid rocks, the major protoliths for mylonites, as well as metamorphosed rocks in the MCT zone are naturally enriched in radioelements; high values associated with sheared and mylonitized zones are coincident with reports of radioelement mineralization and with anomalous radon concentrations in soils. The radioelement abundance as well as REE abundance shows a northward enrichment trend consistent with increasing grade of metamorphism indicating deformation-induced remobilization of these elements. U and Th illustrate good correlation with REEs but not with Zr. This implies that zircon is not a principal carrier of U and Th within the granitoid-dominant thrust zone and that other radioelement-rich secondary minerals are present in considerable amounts. Thus, the relatively flat, less fractionated, HREE trend is also not entirely controlled by zircon. The spatial correlation of geologic boundary zones (faults, sheared zones) with geochemical and with geophysical (Rn

  1. Particle tracking via RFID technology to monitor bedload sediment dynamics in mountain streams

    Science.gov (United States)

    Toro, Matteo; Fraccarollo, Luigi; Corbo, Simona; Maggioni, Alberto; Brardinoni, Francesco

    2015-04-01

    In this contribution we present preliminary results on the monitoring of bedload entrainment and transport in two mountain streams, the Grigno Creek (90 km2) and its tributary, the Tolvà Creek (14 km2), located in Valsugana, Autonomous Province of Trento. In particular, we monitor bedload by means of Radio Frequency Identification (RFID) technology in conjunction with Passive Integrated Transponders (PIT) (e.g., Lamarre et al., 2005) injected into pebble-to-cobble sized tracer stones (b-axis ranging from 30 to 130 mm). In the Grigno Creek 120 PITs were released in December 2013 along a 100-m channel reach and have been surveyed 10 times. In the Tolvà Creek 100 PITs were released in July 2013 along a 100-m channel reach, and the site has been surveyed 4 times. Particle tracking is conducted by integrating two complementary antenna types: (i) a portable one, which enables to estimate travel distances of tagged clasts; and (ii) a set of four fixed antennas (25m apart from each other), which allows detecting motion/rest periods of particles, entrainment thresholds and transport velocities. Particle tracking is combined with on-site high-frequency (i.e., 10 minutes) water stage monitoring. Salt dilution method is monthly applied to relate flow discharge to water stage. The analyzed river reaches extend over different morphologic units (steps, pools, glides and boulder-cascades). We are looking to estimate (i) the channel forming discharge; (ii) a quantitative evaluation of specific bedload transport. These information will be associated to the surficial bed texture and bed morphology. Data collected from fixed and mobile antennas will enable to infer statistical information of the trajectories run by tracer ensemble, in particular the step lengths, the total travel distances and the rest periods. Lamarre H., MacVicar B., Roy A.G. 2005 Using Passive Integrated Transponder (PIT) tags to investigate sediment transport in gravel-bed rivers. Journal of Sedimentary Research

  2. Acoustic streaming in microchannels

    DEFF Research Database (Denmark)

    Tribler, Peter Muller

    , the acoustic streaming flow, and the forces on suspended microparticles. The work is motivated by the application of particle focusing by acoustic radiation forces in medical, environmental and food sciences. Here acoustic streaming is most often unwanted, because it limits the focusability of particles...... oscillating plates. Furthermore, under general thermodynamic conditions, we derive the time-dependent first- and second-order equations for the conservation of mass, momentum, and energy. The coupling from fluid equations to particle motion is achieved through the expressions for the streaming-induced drag...

  3. Analytical Results for 42 Fluvial Tailings Cores and 7 Stream Sediment Samples from High Ore Creek, Northern Jefferson County, Montana

    Science.gov (United States)

    Fey, David L.; Church, Stan E.

    1998-01-01

    Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana have been implicated in their detrimental effects on water quality with regard to acid-generation and toxic-metal solubility. Sediments, fluvial tailings and water from High Ore Creek have been identified as significant contributors to water quality degradation of the Boulder River below Basin, Montana. A study of 42 fluvial tailings cores and 7 stream sediments from High Ore Creek was undertaken to determine the concentrations of environmentally sensitive elements (i.e. Ag, As, Cd, Cu, Pb, Zn) present in these materials, and the mineral phases containing those elements. Two sites of fluvial deposition of mine-waste contaminated sediment on upper High Ore Creek were sampled using a one-inch soil probe. Forty-two core samples were taken producing 247 subsamples. The samples were analyzed by ICP-AES (inductively coupled-plasma atomic emission spectroscopy) using a total mixed-acid digestion. Results of the core analyses show that the elements described above are present at very high concentrations (to 22,000 ppm As, to 460 ppm Ag, to 900 ppm Cd, 4,300 ppm Cu, 46,000ppm Pb, and 50,000 ppm Zn). Seven stream-sediment samples were also analyzed by ICP-AES for total element content and for leachable element content. Results show that the sediment of High Ore Creek has elevated levels of ore-related metals throughout its length, down to the confluence with the Boulder River, and that the metals are, to a significant degree, contained in the leachable phase, namely the hydrous amorphous iron- and manganese-hydroxide coatings on detrital sediment particles.

  4. National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment reconnaissance basic data for Manhattan NTMS Quadrangle, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-13

    Results of a reconnaissance geochemical survey of the Manhattan Quadrangle, Kansas, are reported. Field and laboratory data are presented for 674 groundwater and 718 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. The groundwater data indicate that the most promising area for potential uranium mineralization occurs in the western-northwestern part of the quadrangle where waters are produced from the Quaternary loess deposits, and the Cretaceous Greenhorn-Graneros and Dakota Formations. Associated elements in the quadrangle include arsenic, potassium, manganese, vanadium, and selenium. The stream sediment data indicate that the highest average uranium concentrations in sediments from the Manhattan Quadrangle are obtained from the Pennsylvanian Wabaunsee Group followed by the Cretaceous Carlile Shale, Greenhorn-Graneros and Dakota Formations. In the northwestern corner of the quadrangle, high concentrations of uranium are associated with high concentrations of barium, niobium, strontium, titanium, vanadium, yttrium, and zirconium. In southeast Cloud County and extending to the northeast, high values of total uranium are associated with high values of titanium, yttrium, zirconium, and low U-FL/U-NT values. These associations indicate that the uranium is probably present in heavy and/or resistate minerals.

  5. Effect of Remediation in the Chemical Evolution of Waters and Sediments Along Three Streams Impacted by Acid Mine Drainage in Southeast Ohio

    Science.gov (United States)

    Lopez, D. L.

    2005-12-01

    The chemical evolution of water and sediment along three streams impacted by acid mine drainage in southeast Ohio have been investigated (Sulphur Run in the Federal Creek watershed, Rock Run in the Monday Creek watershed, and Buffer Run in the Raccoon Creek watershed). Sulphur Run neutralizes acidic inputs naturally due to abundant carbonate lithology surrounding the stream. Rock Run and Buffer Run have been anthropogenically remediated using successive alkalinity producing wetlands (SAPS), open limestone channels, and alkaline capping of adjacent coal refuse piles. Sulphur Run has neutral to alkaline pH (which increases away from the AMD source), relatively low acidity and dissolved metals. It has the best overall water quality. However, sediment quality is poor due to mineral precipitation. At Rock Run and Buffer Run, water quality is poorer and pH is lower. Precipitation of metals is occurring at the SAPS and at the stream channel, but it is less significant due to higher solubility of metals at lower pH. Accumulation of metals in the sediments downstream of the SAPS suggests that metal-based compounds precipitated in the SAPS can be transported from there to the stream. In general, a constant supply of alkaline material (such as in watersheds rich in carbonates) may be more effective at improving water quality than passive treatment methods (e.g. SAPS), but without a means of retaining precipitates, sediment quality will be degraded by accumulation of metals in both, anthropogenically remediated AMD streams as well as in naturally remediated streams.

  6. Titanium concentrations in stream sediments from the Atlantic Coastal Plain of the southeastern U.S. (1975-1999)

    Science.gov (United States)

    Ellefsen, Karl J.

    2017-01-01

    The titanium concentrations were obtained from a data set that is called the "National Geochemical Survey." This data set, as well as its documentation, are available in U.S. Geological Survey Open-File Report 2004-1001 (https://mrdata.usgs.gov/geochem/doc/home.htm). The titanium concentrations were measured in 3,457 samples of stream sediments from the coastal plain of the southeastern United States; this area includes parts of Virginia, North Carolina, South Carolina, Georgia, Florida, and Alabama. The samples were collected between 1975 and 1999 during several field surveys, and the concentrations were measured using inductively coupled plasma-atomic emission spectrometry.

  7. Academic streaming in Europe

    DEFF Research Database (Denmark)

    Falaschi, Alessandro; Mønster, Dan; Doležal, Ivan

    2004-01-01

    The TF-NETCAST task force was active from March 2003 to March 2004, and during this time the mem- bers worked on various aspects of streaming media related to the ultimate goal of setting up common services and infrastructures to enable netcasting of high quality content to the academic community...... in Europe. We report on a survey of the use of streaming media in the academic community in Europe, an open source content delivery network, and a portal for announcing live streaming events to the global academic community.......The TF-NETCAST task force was active from March 2003 to March 2004, and during this time the mem- bers worked on various aspects of streaming media related to the ultimate goal of setting up common services and infrastructures to enable netcasting of high quality content to the academic community...

  8. Roads Near Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  9. Future Roads Near Streams

    Data.gov (United States)

    U.S. Environmental Protection Agency — Roads are a source of auto related pollutants (e.g. gasoline, oil and other engine fluids). When roads are near streams, rain can wash these pollutants directly into...

  10. Channelized Streams in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This draft dataset consists of all ditches or channelized pieces of stream that could be identified using three input datasets; namely the1:24,000 National...

  11. Streaming tearing mode

    Science.gov (United States)

    Shigeta, M.; Sato, T.; Dasgupta, B.

    1985-01-01

    The magnetohydrodynamic stability of streaming tearing mode is investigated numerically. A bulk plasma flow parallel to the antiparallel magnetic field lines and localized in the neutral sheet excites a streaming tearing mode more strongly than the usual tearing mode, particularly for the wavelength of the order of the neutral sheet width (or smaller), which is stable for the usual tearing mode. Interestingly, examination of the eigenfunctions of the velocity perturbation and the magnetic field perturbation indicates that the streaming tearing mode carries more energy in terms of the kinetic energy rather than the magnetic energy. This suggests that the streaming tearing mode instability can be a more feasible mechanism of plasma acceleration than the usual tearing mode instability.

  12. Streaming media bible

    National Research Council Canada - National Science Library

    Mack, Steve

    2002-01-01

    This book "tells you everything you need to know to produce professional-quality streaming media for the Internet, from an overview of the available systems and tools to high-end techniques for top quality results...

  13. Scientific stream pollution analysis

    National Research Council Canada - National Science Library

    Nemerow, Nelson Leonard

    1974-01-01

    A comprehensive description of the analysis of water pollution that presents a careful balance of the biological,hydrological, chemical and mathematical concepts involved in the evaluation of stream...

  14. DNR 24K Streams

    Data.gov (United States)

    Minnesota Department of Natural Resources — 1:24,000 scale streams captured from USGS seven and one-half minute quadrangle maps, with perennial vs. intermittent classification, and connectivity through lakes,...

  15. The application of stream sediment and heavy mineral exploratory methods on evaluation of mineralization potential in Soltan Meydan basalts, north of Shahroud

    OpenAIRE

    Mehdi Hashemi Gahrouei; Behnam Shafiei; Gholamhossein. Shamanian; Hossein Taghizadeh

    2012-01-01

    In order to assess the potential of copper mineralization and its associated elements in Soltan Meydan basaltic formation situated in the north of Shahrud, the method of stream sediment and heavy mineral has been used. To achieve this aim, totally 68 samples of sediments (-80 mesh in particle size) and 6 samples of heavy minerals (-20 mesh in particle size) have been collected in an optimized network of sampling. Stream sediment samples have been analyzed in for Cu, Pb, Zn, Co, Mn, Fe and Ni....

  16. Geology and geomorphology control suspended sediment yield and modulate increases following timber harvest in temperate headwater streams

    Science.gov (United States)

    Bywater-Reyes, Sharon; Segura, Catalina; Bladon, Kevin D.

    2017-05-01

    Suspended sediment transport is an important contributor to ecologic and geomorphic functions of streams. However, it is challenging to generalize predictions of sediment yield because it is influenced by many factors. In this study, we quantified the relevance of natural controls (e.g., geology, catchment physiography) on suspended sediment yield (SSY) in headwater streams managed for timber harvest. We collected and analyzed six years of data from 10 sites (five headwater sub-catchments and five watershed outlets) in the Trask River Watershed (western Oregon, United States). We used generalized least squares regression models to investigate how the parameters of the SSY rating curve varied as a function of catchment setting, and whether the setting modulated the SSY response to forest harvesting. Results indicated that the highest intercepts (α) of the power relation between unit discharge and SSY were associated with sites underlain primarily by friable rocks (e.g., sedimentary formations). The greatest increases in SSY after forest harvesting (up to an order of magnitude) also occurred at sites underlain by the more friable lithologies. In contrast, basins underlain by resistant lithologies (intrusive rocks) had lower SSY and were more resilient to management-related increases in SSY. As such, the impact of forest management activities (e.g., use of forested buffers; building of new roads) on the variability in SSY was primarily contingent on catchment lithology. Sites with higher SSY, or harvest-related increases in SSY, also generally had a) lower mean elevation and slope, b) greater landscape roughness, and c) lower sediment connectivity. We used principal component analysis (PCA) to further explore the relationship between SSY and several basin physiographic variables. The PCA clearly separated sites underlain by friable geologic units from those underlain by resistant lithologies. Results are consistent with greater rates of weathering and supply of

  17. Trace Elements in Bed Sediments and Biota from Streams in the Santee River Basin and Coastal Drainages, North and South Carolina, 1995-97

    Science.gov (United States)

    Thomas A. Abrahamsen

    1999-01-01

    Bed-sediment and tissue samples were collected and analyzed for the presence of trace elements from 25 sites in the Santee River Basin and coastal drainages study area during 1995-97 as part of the U.S. Geological Survey's National Water-Quality Assessment Program, Sediment trace-element priority-pollutant concentrations were compared among streams draining water-...

  18. Processes and rates of sediment and wood accumulation in the headwater streams of the Oregon Coast Range, U.S.A.

    Science.gov (United States)

    C. L. May; R. E. Gresswell

    2003-01-01

    Abstract - Channels that have been scoured to bedrock by debris flows provide unique opportunities to calculate the rate of sediment and wood accumulation in low-order streams, to understand the temporal succession of channel morphology following disturbance, and to make inferences about processes associated with input and transport of sediment. Dendrochronology was...

  19. Uranium hydrogeochemical and stream sediment reconnaissance of the Arminto NTMS quadrangle, Wyoming, including concentrations of forty-three additional elements

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, T.L.

    1979-11-01

    During the summers of 1976 and 1977, 570 water and 1249 sediment samples were collected from 1517 locations within the 18,000-km/sup 2/ area of the Arminto NTMS quadrangle of central Wyoming. Water samples were collected from wells, springs, streams, and artifical ponds; sediment samples were collected from wet and dry streams, springs, and wet and dry ponds. All water samples were analyzed for 13 elements, including uranium, and each sediment sample was analyzed for 43 elements, including uranium and thorium. Uranium concentrations in water samples range from below the detection limit to 84.60 parts per billion (ppb) with a mean of 4.32 ppb. All water sample types except pond water samples were considered as a single population in interpreting the data. Pond water samples were excluded due to possible concentration of uranium by evaporation. Most of the water samples containing greater than 20 ppb uranium grouped into six clusters that indicate possible areas of interest for further investigation. One cluster is associated with the Pumpkin Buttes District, and two others are near the Kaycee and Mayoworth areas of uranium mineralization. The largest cluster is located on the west side of the Powder River Basin. One cluster is located in the central Big Horn Basin and another is in the Wind River Basin; both are in areas underlain by favorable host units. Uranium concentrations in sediment samples range from 0.08 parts per million (ppm) to 115.50 ppm with a mean of 3.50 ppm. Two clusters of sediment samples over 7 ppm were delineated. The first, containing the two highest-concentration samples, corresponds with the Copper Mountain District. Many of the high uranium concentrations in samples in this cluster may be due to contamination from mining or prospecting activity upstream from the sample sites. The second cluster encompasses a wide area in the Wind River Basin along the southern boundary of the quadrangle.

  20. Gulf stream separation dynamics

    Science.gov (United States)

    Schoonover, Joseph

    Climate models currently struggle with the more traditional, coarse ( O(100 km) ) representation of the ocean. In these coarse ocean simulations, western boundary currents are notoriously difficult to model accurately. The modeled Gulf Stream is typically seen exhibiting a mean pathway that is north of observations, and is linked to a warm sea-surface temperature bias in the Mid-Atlantic Bight. Although increased resolution ( O(10 km) ) improves the modeled Gulf Stream position, there is no clean recipe for obtaining the proper pathway. The 70 year history of literature on the Gulf Stream separation suggests that we have not reached a resolution on the dynamics that control the current's pathway just south of the Mid-Atlantic Bight. Without a concrete knowledge on the separation dynamics, we cannot provide a clean recipe for accurately modeling the Gulf Stream at increased resolutions. Further, any reliable parameterization that yields a realistic Gulf Stream path must express the proper physics of separation. The goal of this dissertation is to determine what controls the Gulf Stream separation. To do so, we examine the results of a model intercomparison study and a set of numerical regional terraforming experiments. It is argued that the separation is governed by local dynamics that are most sensitive to the steepening of the continental shelf, consistent with the topographic wave arrest hypothesis of Stern (1998). A linear extension of Stern's theory is provided, which illustrates that wave arrest is possible for a continuously stratified fluid.

  1. Contaminants in stream sediments from seven United States metropolitan areas: part I: distribution in relation to urbanization

    Science.gov (United States)

    Nowell, Lisa H.; Moran, Patrick W.; Gilliom, Robert J.; Calhoun, Daniel L.; Ingersoll, Christopher G.; Kemble, Nile E.; Kuivila, Kathryn; Phillips, Patrick J.

    2013-01-01

    Organic contaminants and trace elements were measured in bed sediments collected from streams in seven metropolitan study areas across the United States to assess concentrations in relation to urbanization. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, the pyrethroid insecticide bifenthrin, and several trace elements were significantly related to urbanization across study areas. Most contaminants (except bifenthrin, chromium, nickel) were significantly related to the total organic carbon (TOC) content of the sediments. Regression models explained 45–80 % of the variability in individual contaminant concentrations using degree of urbanization, sediment-TOC, and study-area indicator variables (which represent the combined influence of unknown factors, such as chemical use or release, that are not captured by available explanatory variables). The significance of one or more study-area indicator variables in all models indicates marked differences in contaminant levels among some study areas, even after accounting for the nationally modeled effects of urbanization and sediment-TOC. Mean probable effect concentration quotients (PECQs) were significantly related to urbanization. Trace elements were the major contributors to mean PECQs at undeveloped sites, whereas organic contaminants, especially bifenthrin, were the major contributors at highly urban sites. Pyrethroids, where detected, accounted for the largest share of the mean PECQ. Part 2 of this series (Kemble et al. 2012) evaluates sediment toxicity to amphipods and midge in relation to sediment chemistry.

  2. Contaminants in stream sediments from seven United States metropolitan areas: part I: distribution in relation to urbanization.

    Science.gov (United States)

    Nowell, Lisa H; Moran, Patrick W; Gilliom, Robert J; Calhoun, Daniel L; Ingersoll, Christopher G; Kemble, Nile E; Kuivila, Kathryn M; Phillips, Patrick J

    2013-01-01

    Organic contaminants and trace elements were measured in bed sediments collected from streams in seven metropolitan study areas across the United States to assess concentrations in relation to urbanization. Polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine pesticides, the pyrethroid insecticide bifenthrin, and several trace elements were significantly related to urbanization across study areas. Most contaminants (except bifenthrin, chromium, nickel) were significantly related to the total organic carbon (TOC) content of the sediments. Regression models explained 45-80 % of the variability in individual contaminant concentrations using degree of urbanization, sediment-TOC, and study-area indicator variables (which represent the combined influence of unknown factors, such as chemical use or release, that are not captured by available explanatory variables). The significance of one or more study-area indicator variables in all models indicates marked differences in contaminant levels among some study areas, even after accounting for the nationally modeled effects of urbanization and sediment-TOC. Mean probable effect concentration quotients (PECQs) were significantly related to urbanization. Trace elements were the major contributors to mean PECQs at undeveloped sites, whereas organic contaminants, especially bifenthrin, were the major contributors at highly urban sites. Pyrethroids, where detected, accounted for the largest share of the mean PECQ. Part 2 of this series (Kemble et al. 2012) evaluates sediment toxicity to amphipods and midge in relation to sediment chemistry.

  3. Streaming Pool: reuse, combine and create reactive streams with pleasure

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    When connecting together heterogeneous and complex systems, it is not easy to exchange data between components. Streams of data are successfully used in industry in order to overcome this problem, especially in the case of "live" data. Streams are a specialization of the Observer design pattern and they provide asynchronous and non-blocking data flow. The ongoing effort of the ReactiveX initiative is one example that demonstrates how demanding this technology is even for big companies. Bridging the discrepancies of different technologies with common interfaces is already done by the Reactive Streams initiative and, in the JVM world, via reactive-streams-jvm interfaces. Streaming Pool is a framework for providing and discovering reactive streams. Through the mechanism of dependency injection provided by the Spring Framework, Streaming Pool provides a so called Discovery Service. This object can discover and chain streams of data that are technologically agnostic, through the use of Stream IDs. The stream to ...

  4. Arsenic in New Jersey Coastal Plain streams, sediments, and shallow groundwater: effects from different geologic sources and anthropogenic inputs on biogeochemical and physical mobilization processes

    Science.gov (United States)

    Barringer, Julia L.; Reilly, Pamela A.; Eberl, Dennis D.; Mumford, Adam C.; Benzel, William M.; Szabo, Zoltan; Shourds, Jennifer L.; Young, Lily Y.

    2013-01-01

    Arsenic (As) concentrations in New Jersey Coastal Plain streams generally exceed the State Surface Water Quality Standard (0.017 micrograms per liter (µg/L)), but concentrations seldom exceed 1 µg/L in filtered stream-water samples, regardless of geologic contributions or anthropogenic inputs. Nevertheless, As concentrations in unfiltered stream water indicate substantial variation because of particle inputs from soils and sediments with differing As contents, and because of discharges from groundwater of widely varying chemistry.

  5. Assessing the impacts of climate change and tillage practices on stream flow, crop and sediment yields from the Mississippi River Basin

    Science.gov (United States)

    P.B. Parajuli; P. Jayakody; G.F. Sassenrath; Y. Ouyang

    2016-01-01

    This study evaluated climate change impacts on stream flow, crop and sediment yields from three differ-ent tillage systems (conventional, reduced 1–close to conservation, and reduced 2–close to no-till), in theBig Sunflower River Watershed (BSRW) in Mississippi. The Soil and Water Assessment Tool (SWAT) modelwas applied to the BSRW using observed stream flow and crop...

  6. Interpreting pan-concentrate analysis of stream sediments in geochemical exploration for gold

    Science.gov (United States)

    Fischer, Richard Philip; Fisher, Frederick S.

    1968-01-01

    A study of methods of collecting and processing samples to determine whether or not gold is present in areas of moderate size was undertaken in the northwestern part of the San Juan Mountains, Colo. As part of this study, 57 samples of pan concentrates were taken from streams draining three types of areas: (1)'barren' areas, where gold mineralization might be geologically possible but no deposits are known, (2) slightly mineralized areas that contain only a few known veins and prospects and small mines, and (3) well-mineralized areas that contain numerous veins and some very productive mines. The concentrate samples were analyzed by the fire-assay-atomic-absorption method. Replicate analyses of large samples gave results consistent enough to permit placing considerable confidence in the results obtained for smaller samples on which only one analysis was made. For general field practice, it is necessary to pan only enough sand and gravel to yield about 15 grams of concentrate. The analytical r6sults are also quantitatively compatible with known geologic relations and indicate that a few samples from a stream are adequate to distinguish between 'barren' and mineralized areas and to determine the relative amount of gold in mineralized areas. In other areas of similar gold deposits, data of this type should help decide whether more intensive search for gold deposits is justified.

  7. Streams and their future inhabitants

    DEFF Research Database (Denmark)

    Sand-Jensen, K.; Friberg, N.

    2006-01-01

    In this fi nal chapter we look ahead and address four questions: How do we improve stream management? What are the likely developments in the biological quality of streams? In which areas is knowledge on stream ecology insuffi cient? What can streams offer children of today and adults of tomorrow?...

  8. Preliminary assessment of pseudo-total and bioavailable metals in depth in the sediment of Luíz Rau stream in Novo Hamburgo (RS

    Directory of Open Access Journals (Sweden)

    C. L. Ávila

    Full Text Available The Luíz Rau stream is one of the main streams of Novo Hamburgo. In the stream industrial effluents are released from various sectors, from paint and adhesive industries, metallurgy and leather industry, besides receiving a large amount of domestic sewage. The emissions of these pollutants contribute to decrease water and sediment quality. Within this context, this study evaluated the conditions of the Luíz Rau stream bed sediments, with the determination of the metals like cadmium, lead, chromium and nickel, in depth. To perform the evaluation three points were chosen for sampling along the stream course. The sampling sites were identified as Point A, in Roselândia district and this corresponds to one of the springs and therefore considered as reference value, Point B, in Santo Afonso district being a midpoint of the stream, and Point C also located in Santo Afonso district, near the outfall in Rio dos Sinos river. Cadmium was not detected in any point. At the A and C points chromium was the metal observed in higher concentration in the sediment, up to 45.14 mg kg–1 concentration. In the B point, the metal that was observed in the highest amount was nickel in the concentration of 20.69 mg kg–1.

  9. Concentrations of Arsenic and Boron in Water, Sediment and the Tissues of Fish in Emet Stream (Turkey).

    Science.gov (United States)

    Benzer, Semra

    2017-06-01

    In this study, the concentrations of arsenic and boron were determined in the water and the sediment, as well as in the muscle tissues of Squalius cephalus, Alburnoides bipunctatus, Barbus plebejus and Capoeta tinca from Emet Stream. The fish samples were caught in May 2011 and September 2012. The metal concentrations in the water samples were as follows: arsenic was 137.1-1002 µg L-1, and boron was 2421-14490 µg L-1. The metal concentrations in the sediment samples were as follows: arsenic was 14.51-3317.1 mg kg-1, and boron was 14.22-1014.01 mg kg-1. The mean tissue concentration of arsenic was lower than the TFC and WHO limits. Boron has been identified in fish tissues at concentrations between 0.26 and 2.96 mg kg-1. The bioaccumulation in the muscle tissues of all fish species caught from Emet Stream did not exceed the limit values.

  10. Hydrogeochemical and stream sediment reconnaissance basic data for Sherman NTMS Quadrangle, Texas; Oklahoma. Uranium resource evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    1978-09-29

    Field and laboratory data are presented for 718 groundwater and 715 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate that uranium concentrations above the 85th percentile are predominant in the Trinity Group (Lower Cretaceous), and the Taylor and Navarro Groups (Upper Cretaceous). Values of uranium above the 85th percentile also occur in the Permian units located in the northwestern section of the survey area. Several trends delineating saline water are discernable, the most notable of which occur in sections of the Woodbine Formation and the Permian units. Less distinguishing saline trends occur in many of the Upper Cretaceous formations. Stream sediment data indicate that uranium concentrations above the 85th percentile occur in sections of the Fredericksburg Group parallel to the contact with the Washita Group, in the Eagle Ford Formation, and in the Taylor Group. High values of uranium in the Fredericksburg Group appear to be associated with carbonates and marine clays. High values of uranium in the Eagle Ford Formation are most likely associated with heavy and/or resistate mineral assemblages. High values of uranium occurring in the Taylor Group may be related to the carbonate and phosphatic lithologies which comprise this group.

  11. Spatiotemporal trend analysis of metal concentrations in sediments of a residential California stream with toxicity and regulatory implications.

    Science.gov (United States)

    Hall, Lenwood W; Anderson, Ronald D; Killen, William D

    2017-06-07

    The objective of this study was to determine if concentrations of arsenic, cadmium, chromium, copper, lead, nickel and zinc measured in the sediments of a residential stream in California (Pleasant Grove Creek) have changed temporally or spatially from 2006 to 2016. Threshold Effect Levels (TELs), conservative ecological effects benchmarks, and exceedances for the seven metals were also evaluated over the 11-year time period to provide insight into potential metal toxicity to resident benthic communities. In addition, the bioavailability of metals in sediments was also determined by calculating Simultaneous Extracted Metal/Acid Volatle Sulfide (SEM/AVS) ratios to allow an additional assessment of toxicity. Regulatory implications of this data set and the role of metal toxicity are also discussed. Stream-wide temporal trend analysis showed no statistically significant trends for any of the metals. However, spatial analysis for several sites located near storm drains did show a significant increase for most metals over the 11-year period. TEL exceedances during the 7 years of sampling, spanning 2006-2016, were reported for all metals with the number of exceedances ranging from 47 for copper and zinc to 1 for lead. A spatial analysis showed that the highest number of TEL exceedances and the highest number of SEM/AVS ratios greater than one with at least one metal exceeding a TEL occurred at upstream sites. The potentially toxic metal concentrations reported in Pleasant Grove Creek should be used in the 303 (d) listing process for impaired water bodies in California.

  12. A procedure for estimating Bacillus cereus spores in soil and stream-sediment samples - A potential exploration technique

    Science.gov (United States)

    Watterson, J.R.

    1985-01-01

    The presence of bacterial spores of the Bacillus cereus group in soils and stream sediments appears to be a sensitive indicator of several types of concealed mineral deposits, including vein-type gold deposits. The B. cereus assay is rapid, inexpensive, and inherently reproducible. The test, currently under investigation for its potential in mineral exploration, is recommended for use on a research basis. Among the aerobic spore-forming bacilli, only B. cereus and closely related strains produce an opaque zone in egg-yolk emulsion agar. This characteristic, also known as the Nagler of lecitho-vitellin reaction, has long been used to rapidly indentify and estimate presumptive B. cereus. The test is here adapted to permit rapid estimation of B. cereus spores in soil and stream-sediment samples. Relative standard deviation was 10.3% on counts obtained from two 40-replicate pour-plate determinations. As many as 40 samples per day can be processed. Enough procedural detail is included to permit investigation of the test in conventional geochemical laboratories using standard microbiological safety precautions. ?? 1985.

  13. Uranium concentrations in lake and stream waters and sediments from selected sites in the Susitna River Basin, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Hill, D.E.

    1977-03-01

    During the summer of 1976, 141 water and 211 sediment samples were taken from 147 locations in the Susitna River basin in Alaska by the Geophysical Institute of the University of Alaska for the LASL. These samples were taken to provide preliminary information on the uranium concentrations in waters and sediments from the Susitna River basin and to test the analytical methods proposed for the NURE Hydrogeochemical and Stream Sediment Reconnaissance for uranium in Alaska. The uranium determinations resulting from the fluorometric analysis of the water samples and the delayed-neutron counting of the sediment samples are presented. The low levels of uranium in the water samples, many of which were below the detectable limit of the LASL fluorometric technique, indicate that a more sensitive analytical method is needed for the analysis of Alaskan water samples from this area. An overlay showing numbered sample locations and overlays graphically portraying the concentrations of uranium in the water and sediment samples, all at 1:250,000 scale for use with existing USGS topographic sheets, are also provided as plates.

  14. Multiple stressors in agricultural streams: a mesocosm study of interactions among raised water temperature, sediment addition and nutrient enrichment

    National Research Council Canada - National Science Library

    Piggott, Jeremy J; Lange, Katharina; Townsend, Colin R; Matthaei, Christoph D

    2012-01-01

    ... to empirical surveys, field experiments and laboratory experiments to unravel their individual and combined effects [5]. Agriculture affects streams worldwide, particularly through nutrient enr...

  15. Ecological effects and chemical composition of fine sediments in Upper Austrian streams and resulting implications for river management

    Science.gov (United States)

    Höfler, Sarah; Pichler-Scheder, Christian; Gumpinger, Clemens

    2017-04-01

    In the current scientific discussion high loads of fine sediments are considered one of the most important causes of river ecosystem degradation worldwide. Especially in intensively used catchment areas changes in the sediment household must be regarded as a reason, which prevents the achievement of the objectives of the European Water Framework Directive (WFD). Therefore, the Upper Austrian Water Authorities have launched two comprehensive studies on the topic. The first one was a survey on the current siltation status of river courses in Upper Austria. The second study deals with two selected catchments in detail, in order to get a clear picture of the impacts of the fines on the aquatic fauna (trout eggs, benthic invertebrates), the chemical composition of these fractions, the crucial hydrogeological processes and to develop possible role models for measures both in the catchments and in the streams. At eight sites within the two catchments sediment and water samples were collected at two dates for detailed chemical analysis. On one date additionally the benthic invertebrate fauna was investigated on the microhabitat level. Thereby it was possible to enhance the understanding of the range of ecological impacts caused by silting-up in different hydro-morphological circumstances and with different fine sediment loads. The water samples as well as the sediment fraction samples elements were analysed. Furthermore, a GIS-based analysis was carried out for the two examined catchments. The model included data gained from a digital elevation model, land use data and digital soil classification maps. This led to findings concerning the main sources and processes, which are responsible for anthropogenically induced high fine sediment loads in the streams. According to these results a GIS-based risk assessment tool for all Upper Austrian watercourses is developed, which will be used as instrument for the planning and measure implementation of the water management

  16. Geochemistry and mineralogy of arsenic in mine wastes and stream sediments in a historic metal mining area in the UK.

    Science.gov (United States)

    Rieuwerts, J S; Mighanetara, K; Braungardt, C B; Rollinson, G K; Pirrie, D; Azizi, F

    2014-02-15

    Mining generates large amounts of waste which may contain potentially toxic elements (PTE), which, if released into the wider environment, can cause air, water and soil pollution long after mining operations have ceased. The fate and toxicological impact of PTEs are determined by their partitioning and speciation and in this study, the concentrations and mineralogy of arsenic in mine wastes and stream sediments in a former metal mining area of the UK are investigated. Pseudo-total (aqua-regia extractable) arsenic concentrations in all samples from the mining area exceeded background and guideline values by 1-5 orders of magnitude, with a maximum concentration in mine wastes of 1.8×10(5)mgkg(-1) As and concentrations in stream sediments of up to 2.5×10(4)mgkg(-1) As, raising concerns over potential environmental impacts. Mineralogical analysis of the wastes and sediments was undertaken by scanning electron microscopy (SEM) and automated SEM-EDS based quantitative evaluation (QEMSCAN®). The main arsenic mineral in the mine waste was scorodite and this was significantly correlated with pseudo-total As concentrations and significantly inversely correlated with potentially mobile arsenic, as estimated from the sum of exchangeable, reducible and oxidisable arsenic fractions obtained from a sequential extraction procedure; these findings correspond with the low solubility of scorodite in acidic mine wastes. The work presented shows that the study area remains grossly polluted by historical mining and processing and illustrates the value of combining mineralogical data with acid and sequential extractions to increase our understanding of potential environmental threats. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Analysis of postfire hydrology, water quality, and sediment transport for selected streams in areas of the 2002 Hayman and Hinman fires, Colorado

    Science.gov (United States)

    Stevens, Michael R.

    2013-01-01

    The U.S. Geological Survey (USGS) began a 5-year study in 2003 that focused on postfire stream-water quality and postfire sediment load in streams within the Hayman and Hinman fire study areas. This report compares water quality of selected streams receiving runoff from unburned areas and burned areas using concentrations and loads, and trend analysis, from seasonal data (approximately April–November) collected 2003–2007 at the Hayman fire study area, and data collected from 1999–2000 (prefire) and 2003 (postfire) at the Hinman fire study area. The water-quality data collected during this study include onsite measurements of streamflow, specific conductance, and turbidity, laboratory-determined pH, and concentrations of major ions, nutrients, organic carbon, trace elements, and suspended sediment. Postfire floods and effects on water quality of streams, lakes and reservoirs, drinking-water treatment, and the comparison of measured concentrations to applicable water quality standards also are discussed. Exceedances of Colorado water-quality standards in streams of both the Hayman and Hinman fire study areas only occurred for concentrations of five trace elements (not all trace-element exceedances occurred in every stream). Selected samples analyzed for total recoverable arsenic (fixed), dissolved copper (acute and chronic), total recoverable iron (chronic), dissolved manganese (acute, chronic, and fixed) and total recoverable mercury (chronic) exceeded Colorado aquatic-life standards.

  18. Use of watershed characteristics to select control streams for estimating effects of metal mining wastes on extensively disturbed streams

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, R.M.

    1985-01-01

    Impacts of sediments and heavy metals on the biota of streams in the copper-mining district of southwestern Montana were examined by comparing aquatic communities of impacted streams with those of control streams. Control streams were chosen through the use of a technique that identifies similar streams based on similarities in their watershed characteristics. Significant differences between impacted and control sites existed for surface substrate, riparian vegetation, and the number of macro-invertebrate taxa.

  19. BET surface area distributions in polar stream sediments: Implications for silicate weathering in a cold-arid environment

    Science.gov (United States)

    Marra, Kristen R.; Elwood Madden, Megan E; Soreghan, Gerilyn S.; Hall, Brenda L

    2014-01-01

    BET surface area values are critical for quantifying the amount of potentially reactive sediments available for chemical weathering and ultimately, prediction of silicate weathering fluxes. BET surface area values of fine-grained (processes in the weathering environment. The remaining transects exhibit a range in variability in surface area distributions along the length of the channel, likely related to variations in eolian input to exposed channel beds, adjacent snow drifts, and to glacier surfaces, where dust is trapped and subsequently liberated during summer melting. Additionally, variations in stream discharge rate, which mobilizes sediment in pulses and influences water:rock ratios, the origin and nature of the underlying drift material, and the contribution of organic acids may play significant roles in the production and mobilization of high-surface area sediment. This study highlights the presence of sediments with high surface area in cold-based glacier systems, which influences models of chemical denudation rates and the impact of glacial systems on the global carbon cycle.

  20. Platinum group elements in stream sediments of mining zones: The Hex River (Bushveld Igneous Complex, South Africa)

    Science.gov (United States)

    Almécija, Clara; Cobelo-García, Antonio; Wepener, Victor; Prego, Ricardo

    2017-05-01

    Assessment of the environmental impact of platinum group elements (PGE) and other trace elements from mining activities is essential to prevent potential environmental risks. This study evaluates the concentrations of PGE in stream sediments of the Hex River, which drains the mining area of the Bushveld Igneous Complex (South Africa), at four sampling points. Major, minor and trace elements (Fe, Ca, Al, Mg, Mn, V, Cr, Zn, Cu, As, Co, Ni, Cd, and Pb) were analyzed by FAAS and ETAAS in suspended particulate matter and different sediment fractions (Cr, Pt, Pd, Rh and Ir show concentrations 3-, 13- 18-, 28-, 48- and 44- fold the typical upper continental crust levels, respectively, although lower than concentrations reported for the parent rocks. The highest concentrations were observed closer to the mining area, decreasing with distance and in the <63 μm fraction, probably derived from atmospheric deposition and surface runoff of PGE-rich particles released from mining activities. Thus, mining activities are causing some disturbance of the surface PGE geochemical cycle, increasing the presence of PGE in the fine fraction of river sediments. We propose that indicators such as airborne particulate matter, and soil and river sediment quality, should be added to the protocols for evaluating the sustainability of mining activities.

  1. Flat Branch monitoring project: stream water temperature and sediment responses to forest cutting in the riparian zone

    Science.gov (United States)

    Barton D. Clinton; James M. Vose; Dick L. Fowler

    2010-01-01

    Stream water protection during timber-harvesting activities is of primary interest to forest managers. In this study, we examine the potential impacts of riparian zone tree cutting on water temperature and total suspended solids. We monitored stream water temperature and total suspended solids before and after timber harvesting along a second-order tributary of the...

  2. Stream Water Quality Model

    Data.gov (United States)

    U.S. Environmental Protection Agency — QUAL2K (or Q2K) is a river and stream water quality model that is intended to represent a modernized version of the QUAL2E (or Q2E) model (Brown and Barnwell 1987).

  3. Numerical Modelling of Streams

    DEFF Research Database (Denmark)

    Vestergaard, Kristian

    In recent years there has been a sharp increase in the use of numerical water quality models. Numeric water quality modeling can be divided into three steps: Hydrodynamic modeling for the determination of stream flow and water levels. Modelling of transport and dispersion of a conservative dissol...... dissolved substance. Modeling of chemical and biological turnover of substances....

  4. Streaming-video produktion

    DEFF Research Database (Denmark)

    Grønkjær, Poul

    2004-01-01

     E-learning Lab på Aalborg Universitet har i forbindelse med forskningsprojektet Virtuelle Læringsformer og Læringsmiljøer foretaget en række praktiske eksperimenter med streaming-video produktioner. Hensigten med denne artikel er at formidle disse erfaringer. Artiklen beskriver hele produktionsf...... E-learning Lab på Aalborg Universitet har i forbindelse med forskningsprojektet Virtuelle Læringsformer og Læringsmiljøer foretaget en række praktiske eksperimenter med streaming-video produktioner. Hensigten med denne artikel er at formidle disse erfaringer. Artiklen beskriver hele...... produktionsforløbet: fra ide til færdigt produkt, forskellige typer af præsentationer, dramaturgiske overvejelser samt en konceptskitse. Streaming-video teknologien er nu så udviklet med et så tilfredsstillende audiovisuelt udtryk at vi kan begynde at fokusere på, hvilket indhold der er velegnet til at blive gjort...... tilgængeligt uafhængigt af tid og sted. Afslutningsvis er der en række kildehenvisninger, blandt andet en oversigt over de streaming-video produktioner, som denne artikel bygger på....

  5. The Rabbit Stream Cipher

    DEFF Research Database (Denmark)

    Boesgaard, Martin; Vesterager, Mette; Zenner, Erik

    2008-01-01

    The stream cipher Rabbit was first presented at FSE 2003, and no attacks against it have been published until now. With a measured encryption/decryption speed of 3.7 clock cycles per byte on a Pentium III processor, Rabbit does also provide very high performance. This paper gives a concise...... description of the Rabbit design and some of the cryptanalytic results available....

  6. Music Streaming in Denmark

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Rex

    This report analyses how a ’per user’ settlement model differs from the ‘pro rata’ model currently used. The analysis is based on data for all streams by WiMP users in Denmark during August 2013. The analysis has been conducted in collaboration with Christian Schlelein from Koda on the basis of d...

  7. Riparian deforestation, stream narrowing, and loss of stream ecosystem services

    OpenAIRE

    Sweeney, Bernard W.; Bott, Thomas L.; Jackson, John K.; Kaplan, Louis A.; Newbold, J. Denis; Standley, Laurel J.; Hession, W. Cully; Horwitz, Richard J.

    2004-01-01

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation ...

  8. Bedload sediment transport embedded in seismic signals generated from a mountain stream

    Science.gov (United States)

    Roth, D. L.; Brodsky, E. E.; Finnegan, N. J.; Turowski, J. M.; Wyss, C. R.; Badoux, A.; Schneider, J. M.

    2015-12-01

    We examine broadband (15 - 450 Hz) seismic data from the well-studied Erlenbach stream in the Swiss Prealps, where discharge, precipitation, and bedload transport are independently constrained during flood events. We perform a general linear least squares inversion of seismic data, exploiting times with isolated discharge or rain events, to identify the spectral signals of water turbulence and raindrop impacts. This, in turn, allows us to remove the contributions of turbulence and rainfall from the seismic spectra, thereby isolating the signal of bedload transport. We use one storm to calibrate the regression for bedload transport, then use this regression along with precipitation and discharge data to predict bedload transport rates for the remainder of the two-month campaign. Our predicted bedload transport rates correlate well with transport rates from calibrated geophones embedded in the channel (r2~0.6, pestimation of transport for subsequent periods with only precipitation, discharge and seismic data. Since precipitation and discharge are significantly easier to monitor than transport, this represents a potential application for in-field monitoring of bedload activity.

  9. Map showing geochemical data for panned stream sediments from the Bread Loaf Further Planning Area, Addison and Washington counties, Vermont

    Science.gov (United States)

    Grosz, A.E.; Schruben, P.G.; Atelsek, P.J.

    1987-01-01

    A geochemical survey of bedrock samples in the Bread Loaf Roadless Area (index map; fig. 1) was conducted by the U.S. Geological Survey (USGS) during October, 1981 in order to outline areas that may contain undiscovered mineral deposits. This report describes the results of a geochemical analysis of panned concentrates collected from stream sediments, and complements other geologic and geochemical investigations of the area (Slack and Bitar, 1983). The present study has offered us a chance to identify sampling media and a technique most appropriate for the enhancement of certain metallic elements in samples of panned concentrate. This study is important to the resource evaluation of the Bread Loaf Roadless Area because it reveals that geochemical anomalies produced by this technique are not evident in the standard magnetic and nonmagnetic fractions of panned concentrates.

  10. Review of samples of tailings, soils and stream sediment adjacent to and downstream from the Ruth Mine, Inyo County, California

    Science.gov (United States)

    Rytuba, James J.; Kim, Christopher S.; Goldstein, Daniel N.

    2011-01-01

    The Ruth Mine and mill are located in the western Mojave Desert in Inyo County, California (fig. 1). The mill processed gold-silver (Au-Ag) ores mined from the Ruth Au-Ag deposit, which is adjacent to the mill site. The Ruth Au-Ag deposit is hosted in Mesozoic intrusive rocks and is similar to other Au-Ag deposits in the western Mojave Desert that are associated with Miocene volcanic centers that formed on a basement of Mesozoic granitic rocks (Bateman, 1907; Gardner, 1954; Rytuba, 1996). The volcanic rocks consist of silicic domes and associated flows, pyroclastic rocks, and subvolcanic intrusions (fig. 2) that were emplaced into Mesozoic silicic intrusive rocks (Troxel and Morton, 1962). The Ruth Mine is on Federal land managed by the U.S. Bureau of Land Management (BLM). Tailings from the mine have been eroded and transported downstream into Homewood Canyon and then into Searles Valley (figs. 3, 4, 5, and 6). The BLM provided recreational facilities at the mine site for day-use hikers and restored and maintained the original mine buildings in collaboration with local citizen groups for use by visitors (fig. 7). The BLM requested that the U.S. Geological Survey (USGS), in collaboration with Chapman University, measure arsenic (As) and other geochemical constituents in soils and tailings at the mine site and in stream sediments downstream from the mine in Homewood Canyon and in Searles Valley (fig. 3). The request was made because initial sampling of the site by BLM staff indicated high concentrations of As in tailings and soils adjacent to the Ruth Mine. This report summarizes data obtained from field sampling of mine tailings and soils adjacent to the Ruth Mine and stream sediments downstream from the mine on June 7, 2009. Our results permit a preliminary assessment of the sources of As and associated chemical constituents that could potentially impact humans and biota.

  11. Evaluation of water and sediment of Graminha and Aguas da Serra stream in Limeira (SP) by SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Fazza, Elizete Vieira; Moreira, Silvana [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mails: silvana@fec.unicamp.br; fazzaelizete@yahoo.com

    2007-07-01

    Limeira city is located in the Sao Paulo State, in the second area of the State with the largest economic and demographic growth. It possesses expressive economy, with industries in several productive sections. As the Graminha and Aguas da Serra streams present its nascent ones in the urban zone of the Limeira city, they cross part of the rural zone and it unites draining in the Piracicaba River, it is possible that these basins suffer or have already suffered the impacts related to the environmental pollution caused by anthropogenic factors. Once the city have galvanization industries for the jewels, semi-jewels and bijoux production the descriptions and interpretations of the concentrations of heavy metals, in the water and in the sediments, are indicative to elucidate the influence anthropogenic and the loading of these compounds for Piracicaba River. For the metal determination Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) was used. All measurements were performed using a white beam of synchrotron radiation for excitation and a Ge hyperpure detector. Detection limits for water samples was 0.04 -{mu}g.L{sup -1} and in sediment samples 0.03 {mu}g.g{sup -1} for Cu and Zn elements. In the water samples concentrations higher than permissive values established by CONAMA for Al, Fe, Zn, Cr, Ni, Cu and Pb were observed. For sediment samples values higher than reference value quality defined by CETESB was verified for Cr, Zn, Cu, Ni and Pb. (author)

  12. Small Streams - 50 ft Setback

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is streams extracted from the VHD that have a drainage area of less than two square miles. These streams are given a simple 50-foot setback from top of...

  13. The significance of small streams

    Science.gov (United States)

    Wohl, Ellen

    2017-09-01

    Headwaters, defined here as first- and secondorder streams, make up 70%‒80% of the total channel length of river networks. These small streams exert a critical influence on downstream portions of the river network by: retaining or transmitting sediment and nutrients; providing habitat and refuge for diverse aquatic and riparian organisms; creating migration corridors; and governing connectivity at the watershed-scale. The upstream-most extent of the channel network and the longitudinal continuity and lateral extent of headwaters can be difficult to delineate, however, and people are less likely to recognize the importance of headwaters relative to other portions of a river network. Consequently, headwaters commonly lack the legal protections accorded to other portions of a river network and are more likely to be significantly altered or completely obliterated by land use.

  14. Application of Distributed Temperature Sensing for coupled mapping of sedimentation processes and spatio-temporal variability of groundwater discharge in soft-bedded streams

    DEFF Research Database (Denmark)

    Sebok, Eva; Duque, C; Engesgaard, Peter

    2015-01-01

    The delineation of groundwater discharge areas based on Distributed Temperature Sensing (DTS) data of the streambed can be difficult in soft-bedded streams where sedimentation and scouring processes constantly change the position of the fibre optic cable relative to the streambed. Deposition-indu...

  15. EFDC1D - A ONE DIMENSIONAL HYDRODYNAMIC AND SEDIMENT TRANSPORT MODEL FOR RIVER AND STREAM NETWORKS: MODEL THEORY AND USERS GUIDE

    Science.gov (United States)

    This technical report describes the new one-dimensional (1D) hydrodynamic and sediment transport model EFDC1D. This model that can be applied to stream networks. The model code and two sample data sets are included on the distribution CD. EFDC1D can simulate bi-directional unstea...

  16. Query Processing on Data Streams

    OpenAIRE

    Stegmaier, Bernhard

    2007-01-01

    Data stream processing is currently gaining importance due to the rapid increase in data volumes and developments in novel application areas like e-science, e-health, and e-business. In this thesis, we propose an architecture for a data stream management system and investigate methods for query processing on data streams in such systems. In contrast to traditional database management systems (DBMSs), queries on data streams constitute continuous subscriptions for retrieving interesting data r...

  17. Analysis of hydraulic characteristics for stream diversion in small stream

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sang-Jin; Jun, Kye-Won [Chungbuk National University, Cheongju(Korea)

    2001-10-31

    This study is the analysis of hydraulic characteristics for stream diversion reach by numerical model test. Through it we can provide the basis data in flood, and in grasping stream flow characteristics. Analysis of hydraulic characteristics in Seoknam stream were implemented by using computer model HEC-RAS(one-dimensional model) and RMA2(two-dimensional finite element model). As a result we became to know that RMA2 to simulate left, main channel, right in stream is more effective method in analysing flow in channel bends, steep slope, complex bed form effect stream flow characteristics, than HEC-RAS. (author). 13 refs., 3 tabs., 5 figs.

  18. Net currents in the wave bottom boundary layer: on waveshape streaming and progressive wave streaming

    NARCIS (Netherlands)

    Kranenburg, Wouter; Ribberink, Jan S.; Uittenbogaard, R.E.; Hulscher, Suzanne J.M.H.

    2012-01-01

    The net current (streaming) in a turbulent bottom boundary layer under waves above a flat bed, identified as potentially relevant for sediment transport, is mainly determined by two competing mechanisms: an onshore streaming resulting from the horizontal non-uniformity of the velocity field under

  19. The ecology and biogeochemistry of stream biofilms.

    Science.gov (United States)

    Battin, Tom J; Besemer, Katharina; Bengtsson, Mia M; Romani, Anna M; Packmann, Aaron I

    2016-04-01

    Streams and rivers form dense networks, shape the Earth's surface and, in their sediments, provide an immensely large surface area for microbial growth. Biofilms dominate microbial life in streams and rivers, drive crucial ecosystem processes and contribute substantially to global biogeochemical fluxes. In turn, water flow and related deliveries of nutrients and organic matter to biofilms constitute major constraints on microbial life. In this Review, we describe the ecology and biogeochemistry of stream biofilms and highlight the influence of physical and ecological processes on their structure and function. Recent advances in the study of biofilm ecology may pave the way towards a mechanistic understanding of the effects of climate and environmental change on stream biofilms and the biogeochemistry of stream ecosystems.

  20. Monitoring stream sediment loads in response to agriculture in Prince Edward Island, Canada.

    Science.gov (United States)

    Alberto, Ashley; St-Hilaire, Andre; Courtenay, Simon C; van den Heuvel, Michael R

    2016-07-01

    Increased agricultural land use leads to accelerated erosion and deposition of fine sediment in surface water. Monitoring of suspended sediment yields has proven challenging due to the spatial and temporal variability of sediment loading. Reliable sediment yield calculations depend on accurate monitoring of these highly episodic sediment loading events. This study aims to quantify precipitation-induced loading of suspended sediments on Prince Edward Island, Canada. Turbidity is considered to be a reasonably accurate proxy for suspended sediment data. In this study, turbidity was used to monitor suspended sediment concentration (SSC) and was measured for 2 years (December 2012-2014) in three subwatersheds with varying degrees of agricultural land use ranging from 10 to 69 %. Comparison of three turbidity meter calibration methods, two using suspended streambed sediment and one using automated sampling during rainfall events, revealed that the use of SSC samples constructed from streambed sediment was not an accurate replacement for water column sampling during rainfall events for calibration. Different particle size distributions in the three rivers produced significant impacts on the calibration methods demonstrating the need for river-specific calibration. Rainfall-induced sediment loading was significantly greater in the most agriculturally impacted site only when the load per rainfall event was corrected for runoff volume (total flow minus baseflow), flow increase intensity (the slope between the start of a runoff event and the peak of the hydrograph), and season. Monitoring turbidity, in combination with sediment modeling, may offer the best option for management purposes.

  1. Hysteresis in both sediment transport and water turbulence contribute to seismic hysteresis in a steep mountain stream

    Science.gov (United States)

    Roth, D. L.; Finnegan, N. J.; Brodsky, E. E.; Rickenmann, D.; Turowski, J. M.; Badoux, A.; Gimbert, F.

    2016-12-01

    Hysteresis in the relationship between bedload transport and river stage is a well-documented phenomenon with multiple known causes. Consequently, numerous studies have suggested that hysteresis observed in the relationship between seismic amplitudes recorded near rivers and some measure of flow strength (i.e., discharge or stage) is the signature of bedload transport. We use a metric (Ψ) for the normalized magnitude of hysteresis during individual transport events in the Erlenbach stream (local slope 10%) in the Swiss Prealps to compare hysteresis found in seismic data with hysteresis in in-bed geophone plate system recordings, a well-calibrated proxy for direct sediment transport measurements. We find that while both the geophones and seismometers demonstrate hysteresis, the magnitude and direction of hysteresis are not correlated between these data, indicating that an additional source of hysteresis must be present in the seismic signal. Seismic hysteresis also does not correlate with the magnitude of sediment transport recorded by the geophones, contrary to previous studies' assumptions. Our results indicate that hydrologic sources and changes in water turbulence due to evolving boundary conditions at the bed, rather than changes in sediment transport rates, may sometimes contribute to or even dominate the hysteresis observed in seismic amplitudes near rivers. This appears to be especially relevant in steep rivers where the flow depth is low or comparable to the largest roughness elements on the bed, or where highly turbulent features such as waterfalls or cascades may contribute significantly to the seismic signal. These effects must be better understood in order to determine the extent to which seismic hysteresis may relate to sediment transport rates in different fluvial settings and improve our ability to assess bedload transport and bed evolution through hysteresis in seismic signals near rivers.

  2. Stream-Sediment Geochemistry in Mining-Impacted Drainages of the Yankee Fork of the Salmon River, Custer County, Idaho

    Science.gov (United States)

    Frost, Thomas P.; Box, Stephen E.

    2009-01-01

    This reconnaissance study was undertaken at the request of the USDA Forest Service, Region 4, to assess the geochemistry, in particular the mercury and selenium contents, of mining-impacted sediments in the Yankee Fork of the Salmon River in Custer County Idaho. The Yankee Fork has been the site of hard-rock and placer mining, primarily for gold and silver, starting in the 1880s. Major dredge placer mining from the 1930s to 1950s in the Yankee Fork disturbed about a 10-kilometer reach. Mercury was commonly used in early hard-rock mining and placer operations for amalgamation and recovery of gold. During the late 1970s, feasibility studies were done on cyanide-heap leach recovery of gold from low-grade ores of the Sunbeam and related deposits. In the mid-1990s a major open-pit bulk-vat leach operation was started at the Grouse Creek Mine. This operation shut down when gold values proved to be lower than expected. Mercury in stream sediments in the Yankee Fork ranges from below 0.02 ppm to 7 ppm, with the highest values associated with old mill locations and lode and placer mines. Selenium ranges from below the detection limit for this study of 0.2 ppm to 4 ppm in Yankee Fork sediment samples. The generally elevated selenium content in the sediment samples reflect the generally high selenium contents in the volcanic rocks that underlie the Yankee Fork and the presence of gold and silver selenides in some of the veins that were exploited in the early phases of mining.

  3. Autonomous Byte Stream Randomizer

    Science.gov (United States)

    Paloulian, George K.; Woo, Simon S.; Chow, Edward T.

    2013-01-01

    Net-centric networking environments are often faced with limited resources and must utilize bandwidth as efficiently as possible. In networking environments that span wide areas, the data transmission has to be efficient without any redundant or exuberant metadata. The Autonomous Byte Stream Randomizer software provides an extra level of security on top of existing data encryption methods. Randomizing the data s byte stream adds an extra layer to existing data protection methods, thus making it harder for an attacker to decrypt protected data. Based on a generated crypto-graphically secure random seed, a random sequence of numbers is used to intelligently and efficiently swap the organization of bytes in data using the unbiased and memory-efficient in-place Fisher-Yates shuffle method. Swapping bytes and reorganizing the crucial structure of the byte data renders the data file unreadable and leaves the data in a deconstructed state. This deconstruction adds an extra level of security requiring the byte stream to be reconstructed with the random seed in order to be readable. Once the data byte stream has been randomized, the software enables the data to be distributed to N nodes in an environment. Each piece of the data in randomized and distributed form is a separate entity unreadable on its own right, but when combined with all N pieces, is able to be reconstructed back to one. Reconstruction requires possession of the key used for randomizing the bytes, leading to the generation of the same cryptographically secure random sequence of numbers used to randomize the data. This software is a cornerstone capability possessing the ability to generate the same cryptographically secure sequence on different machines and time intervals, thus allowing this software to be used more heavily in net-centric environments where data transfer bandwidth is limited.

  4. Re-Meandering of Lowland Streams

    DEFF Research Database (Denmark)

    Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

    2014-01-01

    We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinver...

  5. Toward an understanding of "Legacy P" - phosphorus sorption mechanisms in stream sediments as influenced by organic matter

    Science.gov (United States)

    Audette, Yuki; O'Halloran, Ivan P.; Nowell, Peter M.; Congreves, Katelyn; Voroney, R. Paul

    2017-04-01

    -P minerals, even under neutral to alkaline conditions. Thus, where OM-Fe-P forms predominate, we predict a high risk of SRP release from sediments when water chemistry changes. In addition, OM may inhibit the transformation of labile Ca-P forms to more stable Ca-P minerals. Loading of OM affects the development of hypoxia in aquatic systems, and the accumulation of OM can promote the release of both SRP and dissolved organic C to downstream environments. This study provides evidence that the presence of OM in stream sediments influences P sorption mechanisms and is critical in understanding P biogeochemistry in freshwater environments.

  6. Stream-sediment and panned-concentrate geochemical maps of the Buffalo Peaks Wilderness Study Area, Lake, Park, and Chaffee counties, Colorado

    Science.gov (United States)

    Nowlan, G.A.; Gerstel, W.J.

    1985-01-01

    Under provisions of the Wilderness Act (Public Law 88-577, September 3, 1964), the U.S. Geological Survey and the U.S. Bureau of Mines have been conducting mineral surveys of areas selected for possible inclusion in the National Wilderness Preservation System. This report presents results of geochemical studies carried out in June and July, 1982, as part of the investigation of the Buffalo Peaks Wilderness Study Area, Colo. Stream-sediment and panned-concentrate samples were collected from about 80 sites on streams draining the study area. Analytical results and a sample locality map were published by Domenico and others (1984).

  7. Lead and other heavy metals in stream sediments in the area of Meža valley

    Directory of Open Access Journals (Sweden)

    Julija Fux

    2007-12-01

    Full Text Available In the Meža valley, lead – zinc ore has been exploited and processed for more than 300 years, which has strongly influenced the environment.Previous investigation shave shown increased concentrations of lead and some other metals. At the end of the 20th century, the Meža River was considered a stream with the highest concentrations of heavy metals in Slovenia.When the mine and processing plants ceased to operate, the direct transfer of heavy metals into the environment has strongly decreased. However, the deposits of poor ore and wastes from ore processing have remained as an indirect source of heavy metal pollution. From those places heavy metals have been washed out into the nearby streams, and carried into the Meža River and further into the Drava River. Chemical analysis of the Meža River and its tributaries has shown heavy pollution of the upper Meža River sediments with lead, zinc, molybdenum and cadmium, and partly with arsenic. In the lower Meža valley, those concentrations are mildly decreased. Concentrations of cobalt, chrome, copper and nickel are increased in the area around Ravne as a result of the ironworks industry. Mušenik and Jančarjev potok, both tributaries of the Meža River, contribute a high portion of heavy metal load to the Meža River. A specific case is Helenski potok,in which the concentrations of heavy metals strongly surpass the concentrations measured at all other locations. Although more than 10 years have passed since the mine and ore processing plant in the upper Meža valley were closed, the production has ceased and the rehabilitation measures have been taken, the environment in the upper Meža valley is still highly polluted.

  8. Impact of chaparral wildfire-induced sedimentation on oviposition of stream-breeding California newts (Taricha torosa).

    Science.gov (United States)

    Gamradt, Seth C; Kats, Lee B

    1997-05-01

    We examined the effects of chaparral wildfire on stream-breeding California newts (Taricha torosa) in a 750-m stretch of a perennial Santa Monica Mountain stream (Los Angeles County). Detailed field surveys of 1992 and 1993 established the composition (run, riffle, pool) of this habitat and determined the oviposition sites of newts. We also quantified California newt egg mass density and estimated the density of newt adults. A chaparral wildfire burned the entire study site on 2 November 1993. Using the same methods, we collected field survey data in 1994 and 1996. Erosion following the 1993 wildfire produced major changes in stream morphology and composition. Pools and runs represented approximately 40-50% of pre-fire stream area. In the spring following the fire, the stream consisted of less than 20% run and pool. Pools that did remain were often smaller and shallower. The average density of adult California newts did not differ among years. The total number of newt egg masses observed in the spring after the fire was approximately one-third of egg mass counts from pre-fire surveys. Most California newt egg masses were laid in pools and runs; California newts prefer deeper slow-moving water. We conclude that fire-induced landslides and siltation have eliminated pools and runs, thus reducing the amount of habitat suitable for oviposition. Habitat alterations caused by fire likely account for the observed reduction of egg masses at the stream.

  9. Sediment contamination of residential streams in the metropolitan Kansas City area, USA: Part II. Whole-sediment toxicity to the amphipod Hyalella azteca.

    Science.gov (United States)

    Tao, J; Ingersoll, C G; Kemble, N E; Dias, J R; Murowchick, J B; Welker, G; Huggins, D

    2010-10-01

    This is the second part of a study that evaluates the influence of nonpoint sources on the sediment quality of five adjacent streams within the metropolitan Kansas City area, central United States. Physical, chemical, and toxicity data (Hyalella azteca 28-day whole-sediment toxicity test) for 29 samples collected in 2003 were used for this evaluation, and the potential causes for the toxic effects were explored. The sediments exhibited a low to moderate toxicity, with five samples identified as toxic to H. azteca. Metals did not likely cause the toxicity based on low concentrations of metals in the pore water and elevated concentrations of acid volatile sulfide in the sediments. Although individual polycyclic aromatic hydrocarbons (PAHs) frequently exceeded effect-based sediment quality guidelines [probable effect concentrations (PECs)], only four of the samples had a PEC quotient (PEC-Q) for total PAHs over 1.0 and only one of these four samples was identified as toxic. For the mean PEC-Q for organochlorine compounds (chlordane, dieldrin, sum DDEs), 4 of the 12 samples with a mean PEC-Q above 1.0 were toxic and 4 of the 8 samples with a mean PEC-Q above 3.0 were toxic. Additionally, four of eight samples were toxic, with a mean PEC-Q above 1.0 based on metals, PAHs, polychlorinated biphenyls (PCBs), and organochlorine pesticides. The increase in the incidence of toxicity with the increase in the mean PEC-Q based on organochlorine pesticides or based on metals, PAHs, PCBs, and organochlorine pesticides suggests that organochlorine pesticides might have contributed to the observed toxicity and that the use of a mean PEC-Q, rather than PEC-Qs for individual compounds, might be more informative in predicting toxic effects. Our study shows that stream sediments subject to predominant nonpoint sources contamination can be toxic and that many factors, including analysis of a full suite of PAHs and pesticides of both past and present urban applications and the origins of

  10. Sediment contamination of residential streams in the metropolitan kansas city area, USA: Part II. whole-sediment toxicity to the amphipod hyalella azteca

    Science.gov (United States)

    Tao, J.; Ingersoll, C.G.; Kemble, N.E.; Dias, J.R.; Murowchick, J.B.; Welker, G.; Huggins, D.

    2010-01-01

    This is the second part of a study that evaluates the influence of nonpoint sources on the sediment quality of five adjacent streams within the metropolitan Kansas City area, central United States. Physical, chemical, and toxicity data (Hyalella azteca 28-day whole-sediment toxicity test) for 29 samples collected in 2003 were used for this evaluation, and the potential causes for the toxic effects were explored. The sediments exhibited a low to moderate toxicity, with five samples identified as toxic to H. azteca. Metals did not likely cause the toxicity based on low concentrations of metals in the pore water and elevated concentrations of acid volatile sulfide in the sediments. Although individual polycyclic aromatic hydrocarbons (PAHs) frequently exceeded effect-based sediment quality guidelines [probable effect concentrations (PECs)], only four of the samples had a PEC quotient (PEC-Q) for total PAHs over 1.0 and only one of these four samples was identified as toxic. For the mean PEC-Q for organochlorine compounds (chlordane, dieldrin, sum DDEs), 4 of the 12 samples with a mean PEC-Q above 1.0 were toxic and 4 of the 8 samples with a mean PEC-Q above 3.0 were toxic. Additionally, four of eight samples were toxic, with a mean PEC-Q above 1.0 based on metals, PAHs, polychlorinated biphenyls (PCBs), and organochlorine pesticides. The increase in the incidence of toxicity with the increase in the mean PEC-Q based on organochlorine pesticides or based on metals, PAHs, PCBs, and organochlorine pesticides suggests that organochlorine pesticides might have contributed to the observed toxicity and that the use of a mean PEC-Q, rather than PEC-Qs for individual compounds, might be more informative in predicting toxic effects. Our study shows that stream sediments subject to predominant nonpoint sources contamination can be toxic and that many factors, including analysis of a full suite of PAHs and pesticides of both past and present urban applications and the origins of

  11. Delineating incised stream sediment sources within a San Francisco Bay tributary basin

    Science.gov (United States)

    Bigelow, Paul; Benda, Lee; Pearce, Sarah

    2016-07-01

    Erosion and sedimentation pose ubiquitous problems for land and watershed managers, requiring delineation of sediment sources and sinks across landscapes. However, the technical complexity of many spatially explicit erosion models precludes their use by practitioners. To address this critical gap, we demonstrate a contemporary use of applied geomorphometry through a straightforward GIS analysis of sediment sources in the San Francisco Bay Area in California, USA, designed to support erosion reduction strategies. Using 2 m lidar digital elevation models, we delineated the entire river network in the Arroyo Mocho watershed (573 km2) at the scale of ˜ 30 m segments and identified incised landforms using a combination of hillslope gradient and planform curvature. Chronic erosion to the channel network was estimated based on these topographic attributes and the size of vegetation, and calibrated to sediment gage data, providing a spatially explicit estimate of sediment yield from incised channels across the basin. Rates of erosion were summarized downstream through the channel network, revealing patterns of sediment supply at the reach scale. Erosion and sediment supply were also aggregated to subbasins, allowing comparative analyses at the scale of tributaries. The erosion patterns delineated using this approach provide land use planners with a robust framework to design erosion reduction strategies. More broadly, the study demonstrates a modern analysis of important geomorphic processes affected by land use that is easily applied by agencies to solve common problems in watersheds, improving the integration between science and environmental management.

  12. Seasonal Arsenic Accumulation in Stream Sediments at a Groundwater Discharge Zone

    DEFF Research Database (Denmark)

    MacKay, Allison A.; Gan, Ping; Yu, Ran

    2014-01-01

    Seasonal changes in arsenic and iron accumulation rates were examined in the sediments of a brook that receives groundwater discharges of arsenic and reduced iron. Clean glass bead columns were deployed in sediments for known periods over the annual hydrologic cycle to monitor changes in arsenic......(As)/mg(Fe)) of unreacted iron oxide solids. The flooded spring (March-June) with high surface water flows showed the lowest arsenic and iron accumulation rates in the sediments. Comparisons of accumulation rates across a shoreline transect were consistent with greater rates at regions exposed above surface water levels...

  13. Trace elements in bed sediments and aquatic invertebrates from three streams in Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, S. [Geological Survey, Carson City, NV (United States). Water Resources Div.

    1995-12-31

    In September 1992, the US Geological Survey, as part of the National Water Quality Assessment Program, collected crayfish (Pacifastacus Ieniusculus and Procambarus clarkii), asiatic clam (Corbicula fluminea), caddis-fly larvae (Hydropsyche spp.) and bed-sediment samples from the Truckee and Carson Rivers, and Las Vegas Wash in Nevada and analyzed them for selected trace elements. This report describes and compares the concentrations of arsenic, copper, manganese, mercury, silver, and zinc in those samples. In the Truckee and Carson Rivers, concentrations of the six trace elements in aquatic invertebrate samples are similar to concentrations measured in bed sediments. In the Truckee River, concentrations of these elements in crayfish and bed-sediment samples were highest in the Reno-Sparks urban area. In the Carson River, arsenic and copper are highest in bed-sediment samples upstream of Carson City due to geothermal springs and acid-mine drainage from an abandoned sulfur mine; concentrations of manganese, mercury, silver, and zinc were highest in bed-sediment samples collected downstream of the Carson City urban area due to historic gold and silver mining, and urban runoff. The highest mercury concentration in crayfish tissue, 48 {micro}g/g dry weight, was measured in a sample from the lower Carson River. In Las Vegas Wash, bed-sediment concentrations were lower than those in the Truckee and Carson Rivers; but, trace-element concentrations in crayfish tissue tended to be higher than those in bed sediment. Samples collected during this study show that trace elements are enriched in the bed sediments of all three rivers and are bioavailable. Trace-element concentrations among samples of crayfish, asiatic clam, and caddis-fly larvae showed little similarity.

  14. Uranium hydrogeochemical and stream sediment reconnaissance of the Trinidad NTMS Quadrangle, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Morris, W.A.; LaDelfe, C.M.; Weaver, T.A.

    1978-10-01

    During the field seasons of 1976 and 1977, 1,060 natural water and 1,240 waterborne sediment samples were collected from 1,768 locations in the Trinidad, Colorado, NTMS quadrangle. The samples from this 19,600-km/sup 2/ area were analyzed at the Los Alamos Scientific Laboratory for total uranium. The uranium concentrations in waters ranged from less than the detection limit of 0.02 parts per billion (ppb) to 88.3 ppb, with a mean value of 4.05 ppb. The concentrations in sediments ranged from 1.3 parts per million (ppM) to 721.9 ppM, with a mean value of 5.55 ppM. Based on simple statistical analyses of these data, arbitrary anomaly thresholds were set at 20 ppb for water samples and 12 ppM for sediment samples. By this definition, fifty-eight water and 39 sediment samples were considered anomalous. At least five areas delineated by the data appear to warrant more detailed investigations. Twenty-six anomalous water samples outline a broad area corresponding to the axis of the Apishapa uplift, seven others form a cluster in Huerfano Park, and five others outline a small area in the northern part of the San Luis Valley. Twenty-three anomalous sediment samples outline an area corresponding generally to Precambrian metamorphic rocks in the Culebra Range, and seven anomalous sediment samples form a cluster near Crestone Peak in the Sangre de Cristo Mountains.

  15. Environmental fate of pyrethroids in urban and suburban stream sediments and the appropriateness of Hyalella azteca model in determining ecological risk.

    Science.gov (United States)

    Palmquist, Katherine; Fairbrother, Anne; Salatas, Johanna; Guiney, Patrick D

    2011-07-01

    According to several recent studies using standard acute Hyalella azteca sediment bioassays, increased pyrethroid use in urban and suburban regions in California has resulted in the accumulation of toxic concentrations of pyrethroids in sediments of area streams and estuaries. However, a critical review of the literature indicates that this is likely an overestimation of environmental risk. Hyalella azteca is consistently the most susceptible organism to both aqueous and sediment-associated pyrethroid exposures when compared to a suite of other aquatic taxa. In some cases, H. azteca LC50 values are less than the community HC10 values, suggesting that the amphipod is an overly conservative model for community- or ecosystem-level impacts of sediment-associated pyrethroids. Further, as a model for responses of field populations of H. azteca, the laboratory bioassays considerably overestimate exposure, because the amphipod is more appropriately characterized as an epibenthic organism, not a true sediment dweller; H. azteca preferentially inhabit aquatic macrophytes, periphyton mats, and leaf litter, which drastically reduces their exposure to contaminated sediments. Sediment-bound pyrethroids are transported via downstream washing of fine particulates resulting in longer range transport but also more efficient sequestration of the chemical. In addition, site-specific variables such as sediment organic carbon content, grain size, temperature, and microbial activity alter pyrethroid bioavailability, degradation, and toxicity on a microhabitat scale. The type and source of the carbon in particular, influences the pyrethroid sequestering ability of sediments. The resulting irregular distribution of pyrethroids in stream sediments suggests that sufficient nonimpacted habitat may exist as refugia for resident sediment-dwelling organisms for rapid recolonization to occur. Given these factors, we argue that the amphipod model provides, at best, a screening level assessment of

  16. The effects of unpaved roads on suspended sediment concentration of third- to fifth-order streams- A case study from southern Brazil

    Science.gov (United States)

    Thomaz, E. L.; Vestena, L. R.; Ramos-Scharron, C. E.

    2012-12-01

    Unpaved roads have earned a reputation of inducing adverse effects on downstream water resources by increasing suspended sediment concentration because they typically generate sediment at rates up to several orders of magnitude above background and because they may enhance the efficiency of sediment delivery to fluvial networks. Although much research has been conducted on road effects in forested landscapes, proper understanding of their hydro-geomorphic role in rural areas is still desired. Unpaved roads are fundamental in the agricultural systems employed for the cultivation of maize and black beans on topographically-steep, marginal lands of southern Brazil. Marginal lands generate a sizeable fraction of the agricultural production in the state of Paraná, one of Brazil's agricultural powerhouses. This study documents the localized impacts on suspended sediment concentration of seven unpaved road crossings in the Guarabiroba River Catchment, Paraná, Brazil. A total of 156 suspended sediment samples were manually collected both upstream and downstream of road-crossings between 22-Apr-09 and 26-Apr-10 during 14 rainfall events ranging between 16 and 96 mm in total rainfall. The average length of road directly delivering runoff to each crossing varied from 0.56 - 2.4 km, and the size of the catchment areas of the third to fifth order monitored streams ranged from 0.3 to 13.5 km2. In addition to stream samples, 78 samples representing unpaved road runoff were collected during the same rain events. Upstream and downstream mean concentration values were compared for each storm at every site based on a paired t-test analysis (0.05% level). Mean suspended sediment concentration at stream segments located upstream of road crossings was 0.04 mg L-1 (s.d. = 0.05 mg L-1), while the mean downstream concentration was 0.11 mg L-1 (s.d. = 0.14 mg L-1) or 2.9 times higher than upstream samples. Meanwhile, road runoff had an average concentration of 0.93 mg L-1 (s.d. = 0.97 mg

  17. Uranium hydrogeochemical and stream sediment reconnaissance in Lincoln and Flathead Counties, northwest Montana

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, P.L.

    1977-05-01

    Between mid-May and late June 1976, 3409 water and water-transported sediment samples were collected from 1781 locations spread over an approximate 17000-km/sup 2/ area of northwestern Montana. All of the samples were analyzed for total uranium at the LASL, using standardized procedures and rigorous quality controls, the waters by fluorometry and the sediment (and those waters with greater than 10 ppb uranium) by delayed-neutron counting methods. All of the field collection, treatment, and packaging of the samples was performed following strict LASL specifications. The uranium concentrations measured in the waters range from undetectable (less than 0.2) ppb to 173.6 ppb, but average only 0.66 ppb. The low uranium concentrations in the waters of this area are thought to be due primarily to a general lack of readily soluble uranium and dilution with spring runoff. Those locations which did have abnormally high uranium were examined more closely, and follow-up field examinations are recommended in the vicinity of some of these sites. The uranium content of the sediment samples range from 0.5 ppM to 52.2 ppM and average 4.56 ppM. Sample locations with high and/or anomalous uranium values were examined with respect to the local geology, water chemistry, and other relevant factors. A distinct correlation between the high uranium in sediment and epithermal and mesothermal veins associated with nearby faults and folds is evident at several locations. Areas believed to be favorable for follow-up field investigations based on the sediment data are indicated. A correlation between high uranium in water and high uranium in sediment is evident at only a single location. The generally low uranium concentrations in water and moderate concentrations in sediment seem to indicate that most of the uranium that does exist in this area is bound up in resistant minerals.

  18. STREAM2016: Streaming Requirements, Experience, Applications and Middleware Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Geoffrey [Indiana Univ., Bloomington, IN (United States); Jha, Shantenu [Rutgers Univ., New Brunswick, NJ (United States); Ramakrishnan, Lavanya [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-01

    The Department of Energy (DOE) Office of Science (SC) facilities including accelerators, light sources and neutron sources and sensors that study, the environment, and the atmosphere, are producing streaming data that needs to be analyzed for next-generation scientific discoveries. There has been an explosion of new research and technologies for stream analytics arising from the academic and private sectors. However, there has been no corresponding effort in either documenting the critical research opportunities or building a community that can create and foster productive collaborations. The two-part workshop series, STREAM: Streaming Requirements, Experience, Applications and Middleware Workshop (STREAM2015 and STREAM2016), were conducted to bring the community together and identify gaps and future efforts needed by both NSF and DOE. This report describes the discussions, outcomes and conclusions from STREAM2016: Streaming Requirements, Experience, Applications and Middleware Workshop, the second of these workshops held on March 22-23, 2016 in Tysons, VA. STREAM2016 focused on the Department of Energy (DOE) applications, computational and experimental facilities, as well software systems. Thus, the role of “streaming and steering” as a critical mode of connecting the experimental and computing facilities was pervasive through the workshop. Given the overlap in interests and challenges with industry, the workshop had significant presence from several innovative companies and major contributors. The requirements that drive the proposed research directions, identified in this report, show an important opportunity for building competitive research and development program around streaming data. These findings and recommendations are consistent with vision outlined in NRC Frontiers of Data and National Strategic Computing Initiative (NCSI) [1, 2]. The discussions from the workshop are captured as topic areas covered in this report's sections. The report

  19. Sedimentation of particles and aggregates in colloids considering both streaming and seepage

    Science.gov (United States)

    Song, Dongxing; Jin, Hui; Jin, Jingyu; Jing, Dengwei

    2016-10-01

    Sedimentation of colloids is a common phenomenon in various industrial processes. Aggregation of nanoparticles is expected to occur during the processes. However, previous studies often ignore the important features of aggregates, e.g. porosity and possible seepage, leading to a mathematical description of the sedimentation processes of low reliability. In this study, we successfully elaborated the partial differential equation of the dynamic concentration distribution of regimented colloids based on the Stokes approximation and diffusion along the negative gradient of concentration. The permeability of aggregates was obtained by the finite volume method and the ratios of the velocities of flowing around (u f) to seepage through (u s) aggregates over various primary particle sizes and aggregation structures were obtained based on the Darcy equations. After validation of the model, the effects of size and density of the particles and aggregates on the concentration profiles were investigated. Our results indicate that both an increase in size and density of particles and aggregates can accelerate the sedimentation process, and lead to more ‘thorough’ sedimentation. We mathematically explain why suspensions with high particle concentration are more unstable. What is more, replacing gravity with other volume forces, e.g. centrifugal force and magnetic forces, our model is expected to be applicable to centrifugation or magnetic sedimentation processes.

  20. Occurrence and partitioning of antibiotic compounds found in the water column and bottom sediments from a stream receiving two wastewater treatment plant effluents in Northern New Jersey, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Gibs, Jacob, E-mail: jgibs@usgs.gov [U.S. Geological Survey, 810 Bear Tavern Road, West Trenton, NJ 08628 (United States); Heckathorn, Heather A. [U.S. Geological Survey, 810 Bear Tavern Road, West Trenton, NJ 08628 (United States); Meyer, Michael T. [U.S. Geological Survey, 4821 Quail Crest Place, Lawrence, KS 66049 (United States); Klapinski, Frank R.; Alebus, Marzooq; Lippincott, Robert L. [New Jersey Department of Environmental Protection, PO Box 413, Trenton, NJ 08625 (United States)

    2013-08-01

    An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September 2008. Two of the nine sampling locations were background sites upstream from two WWTP discharges on Hohokus Brook. Another background site was located upstream from a DWI on the Saddle River above the confluence with Hohokus Brook. Because there is a weir downstream of the confluence of Hohokus Brook and Saddle River, the DWI receives water from Hohokus Brook at low stream flows. Eight antibiotic compounds (azithromycin (maximum concentration 0.24 μg/L), ciprofloxacin (0.08 μg/L), enrofloxacin (0.015 μg/L), erythromycin (0.024 μg/L), ofloxacin (0.92 μg/L), sulfamethazine (0.018 μg/L), sulfamethoxazole (0.25 μg/L), and trimethoprim (0.14 μg/L)) and a degradate (erythromycin–H{sub 2}O (0.84 μg/L)) were detected in the water samples from the sites downstream from the WWTP discharges. The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin

  1. Uranium hydrogeochemical and stream sediment reconnaissance data release for the Dubois NTMS Quadrangle, Idaho/Montana, including concentrations of forty-five additional elements

    Energy Technology Data Exchange (ETDEWEB)

    LaDelfe, C.M.

    1980-08-01

    Totals of 1024 water samples and 1600 sediment samples were collected from 1669 locations in the Dubois quadrangle. Water samples were taken at streams, springs, and wells; sediment samples were collected from streams and springs. All field and analytical data are presented for waters in Appendix I-A and for sediments in I-B. All elemental analyses were performed at the LASL. Water samples were initially analyzed for uranium by fluorometry. All water samples containing more than the upper detection limit of uranium were reanalyzed by delayed neutron counting. Sediments were analyzed for uranium and thorium as well as aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, cerium, cesium, chlorine, chromium, cobalt, copper, dysprosium, europium, gold, hafnium, iron, lanthanum, lead, lithium, lutetium, magnesium, manganese, nickel, niobium, potassium rubidium, samarium, scandium, selenium, silver, sodium, strontium, tantalum, terbium, tin, titanium, tungsten, vanadium, ytterbium, zinc and zirconium. All sediments were analyzed for uranium by delayed-neutron counting. Other elemental concentrations in sediments were determined by neutron-activation analysis for 30 elements, by x-ray fluorescence for 12 elements, and by arc-source emission spectrography for 2 elements. Analytical results for sediments are reported as parts per million.

  2. Effects of sediment transport on survival of salmonid embryos in a natural stream: A simulation approach

    Science.gov (United States)

    Thomas E. Lisle; Jack Lewis

    1992-01-01

    A model is presented that simulates the effects of streamflow and sediment transport on survival of salmonid embryos incubating in spawning gravels in a natural channel. Components of the model include a 6-yr streamflow record, an empirical bed load-transport function, a relation between transport and infiltration of sandy bedload into a gravel bed, effects of fine-...

  3. Assessment of trace metal contamination in stream sediments of the Tuul River, Mongolia

    Science.gov (United States)

    Dalai, B.

    2011-12-01

    Thirty four sediment samples were collected in Ulaanbaatar basin, along the Tuul River which is the main source of water for the capital city Ulaanbaatar, Mongolia. The catchment can be divided three parts (upper, middle, and lower) according to the extent of urbanization. The upper part of the river basin is comparatively less affected by human activity and it can be represent the natural background condition. The middle part is the urban area of Ulaanbaatar and lower part extends SW of the end of the urban area mostly used for agriculture and farming activity. The present study focused on the levels of potentially toxic metals such as As, Pb, Zn, Cu, Ni and Cr in order to assess the extent of environmental pollution and to discuss the origin of these contaminants in sediments of the Tuul River using X-ray fluorescence analyses. Metal concentrations in the sediments are discussed by comparison with average Upper Continental Crust values (UCC) and ecological risk assessment by reference to sediment quality guidelines (SQG). The results showed thet average abundances of metals are measurable contrast between upper, middle and lower parts of the river. The Upper part and its surrounding area's sediment signature indicated that more depletion comparatively other parts (Pb, Zn, Cu, Ni and Cr), whereas enrichment sign did not detect. However, among the Upper part sediments, two samples (NA1 and NA2) enriched with trace metals which sampled from Nalaikh area were significantly affected by coal mining activity. Most metals are (As, Pb, Zn, Cu and Ni) higher in the middle part (within the city) than the upper and lower part due to the urban activities. The small tributaries such as Selbe, Uliastai, Gachuurt and Tolgoit were significantly affected by urban activities and highest values are detected from them. Lower part significantly enriched with Cr (av 98 ppm). Highest concentration of Cr (183 ppm) was at Shuvuu which is receiving point of domestic and industrial

  4. The California stream quality assessment

    Science.gov (United States)

    Van Metre, Peter C.; Egler, Amanda L.; May, Jason T.

    2017-03-06

    In 2017, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project is assessing stream quality in coastal California, United States. The USGS California Stream Quality Assessment (CSQA) will sample streams over most of the Central California Foothills and Coastal Mountains ecoregion (modified from Griffith and others, 2016), where rapid urban growth and intensive agriculture in the larger river valleys are raising concerns that stream health is being degraded. Findings will provide the public and policy-makers with information regarding which human and natural factors are the most critical in affecting stream quality and, thus, provide insights about possible approaches to protect the health of streams in the region.

  5. The LHCb Turbo Stream

    CERN Document Server

    Benson, Sean; Vesterinen, Mika Anton; Williams, John Michael

    2015-01-01

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction and discarding the raw event. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses, and this will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissi...

  6. The LHCb Turbo Stream

    CERN Document Server

    Benson, Sean

    2015-01-01

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the "turbo stream" the trigger will write out a compact summary of "physics" objects containing all information necessary for analyses, and this will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during...

  7. The LHCb Turbo stream

    CERN Document Server

    AUTHOR|(CDS)2070171

    2016-01-01

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger will write out a compact summary of physics objects containing all information necessary for analyses. This will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during 2015 wi...

  8. Effects of rapid urbanization on streamflow, erosion, and sedimentation in a desert stream in the American Southwest

    Science.gov (United States)

    Whitney, John W.; Glancy, Patrick A.; Buckingham , Susan E.; Ehrenberg, Arthur C.

    2015-01-01

    Rapid urbanization has resulted in a series of sequential effects on a desert stream in the American Southwest. Lower Las Vegas Wash was a dry wash characterized by infrequent flood deposition when Las Vegas, Nevada was established in 1905. Wastewater effluent was discharged into the wash in low volumes for over 3 decades. Wastewater volumes increased commensurably with accelerated population growth during the late 20th century and created a sequence of feedback effects on the floodplain. Initially slow saturation of the valley fill created a desert oasis of dense floodplain vegetation and wetlands. Annual streamflow began in 1958 and erosion began a decade later with shallow incision in discontinuous channel segments. Increasing baseflow gradually enlarged channels; headcutting was active during the 1970s to 1984. The incised channels concentrated storm runoff, which accelerated local channel erosion, and in 1984 the headcuts were integrated during a series of monsoon floods. Wetlands were drained and most floodplain vegetation destroyed. Channel erosion continued unabated until engineering interventions began in the 21st century. No natural channel recovery occurred after initial urbanization effects because streamflow never stabilized in the late 20th century. A 6.6 M m3 sediment slug, eroded from the wash in ∼25 years, was deposited in Las Vegas Bay in Lake Mead. Falling reservoir levels during the 21st century are responsible for sediment redistribution and infilling of the bay. Close monitoring of impacts is recommended when urban wastewater and storm runoff are discharged on a desert wash. Channel interventions, when necessary, are advised in order to prevent costly engineering schemes of channel stabilization, flood control, and floodplain restoration.

  9. Stream salamanders as indicators of stream quality in Maryland, USA

    Science.gov (United States)

    Southerland, M.T.; Jung, R.E.; Baxter, D.P.; Chellman, I.C.; Mercurio, G.; Volstad, J.H.

    2004-01-01

    Biological indicators are critical to the protection of small, headwater streams and the ecological values they provide. Maryland and other state monitoring programs have determined that fish indicators are ineffective in small streams, where stream salamanders may replace fish as top predators. Because of their life history, physiology, abundance, and ubiquity, stream salamanders are likely representative of biological integrity in these streams. The goal of this study was to determine whether stream salamanders are effective indicators of ecological conditions across biogeographic regions and gradients of human disturbance. During the summers of 2001 and 2002, we intensively surveyed for stream salamanders at 76 stream sites located west of the Maryland Coastal Plain, sites also monitored by the Maryland Biological Stream Survey (MBSS) and City of Gaithersburg. We found 1,584 stream salamanders, including all eight species known in Maryland, using two 15 ? 2 m transects and two 4 m2 quadrats that spanned both stream bank and channel. We performed removal sampling on transects to estimate salamander species detection probabilities, which ranged from 0.67-0.85. Stepwise regressions identified 15 of 52 non-salamander variables, representing water quality, physical habitat, land use, and biological conditions, which best predicted salamander metrics. Indicator development involved (1) identifying reference (non-degraded) and degraded sites (using percent forest, shading, riparian buffer width, aesthetic rating, and benthic macroinvertebrate and fish indices of biotic integrity); (2) testing 12 candidate salamander metrics (representing species richness and composition, abundance, species tolerance, and reproductive function) for their ability to distinguish reference from degraded sites; and (3) combining metrics into an index that effectively discriminated sites according to known stream conditions. Final indices for Highlands, Piedmont, and Non-Coastal Plain

  10. Data streams algorithms and applications

    CERN Document Server

    Muthukrishnan, S

    2014-01-01

    Data stream algorithms as an active research agenda emerged only over the past few years, even though the concept of making few passes over the data for performing computations has been around since the early days of Automata Theory. The data stream agenda now pervades many branches of Computer Science including databases, networking, knowledge discovery and data mining, and hardware systems. Industry is in synch too, with Data Stream Management Systems (DSMSs) and special hardware to deal with data speeds. Even beyond Computer Science, data stream concerns are emerging in physics, atmospheric

  11. Ex-Stream: A MATLAB program for calculating fluid flux through sediment-water interfaces based on steady and transient temperature profiles

    Science.gov (United States)

    Swanson, Travis E.; Cardenas, M. Bayani

    2011-10-01

    Temperature is a useful environmental tracer for quantifying movement and exchange of water and heat through and near sediment-water interfaces (SWI). Heat tracing involves analyzing temperature time series or profiles from temperature probes deployed in sediments. Ex-Stream is a MATLAB program that brings together two transient and two steady one-dimensional coupled heat and fluid flux analytical models. The program includes a graphical user interface, a detailed user manual, and postprocessing capabilities that enable users to extract fluid fluxes from time-series temperature observations. Program output is written to comma-separated values files, displayed within the MATLAB command window, and may be optionally plotted. The models that are integrated into Ex-Stream can be run collectively, allowing for direct comparison, or individually.

  12. Occurrence and distribution of trace elements in snow, streams, and streambed sediments, Cape Krusenstern National Monument, Alaska, 2002-2003

    Science.gov (United States)

    Brabets, Timothy P.

    2004-01-01

    Cape Krusenstern National Monument is located in Northwest Alaska. In 1985, an exchange of lands and interests in lands between the Northwest Alaska Native Association and the United States resulted in a 100-year transportation system easement for 19,747 acres in the monument. A road was then constructed along the easement from the Red Dog Mine, a large zinc concentrate producer and located northeast of the monument, through the monument to the coast and a port facility. Each year approximately 1.3 million tonnes of zinc and lead concentrate are transported from the Red Dog Mine via this access road. Concern about the possible deposition of cadmium, lead, zinc and other trace elements in the monument was the basis of a cooperative project with the National Park Service. Concentrations of dissolved cadmium, dissolved lead, and dissolved zinc from 28 snow samples from a 28 mile by 16 mile grid were below drinking water standards. In the particulate phase, approximately 25 percent of the samples analyzed for these trace elements were higher than the typical range found in Alaska soils. Boxplots of concentrations of these trace elements, both in the dissolved and particulate phase, indicate higher concentrations north of the access road, most likely due to the prevailing southeast wind. The waters of four streams sampled in Cape Krusenstern National Monument are classified as calcium bicarbonate. Trace-element concentrations from these streams were below drinking water standards. Median concentrations of 39 trace elements from streambed sediments collected from 29 sites are similar to the median concentrations of trace elements from the U.S. Geological Survey?s National Water-Quality Assessment database. Statistical differences were noted between trace-element concentrations of cadmium, lead, and zinc at sites along the access road and sites north and south of the access road; concentrations along the access road being higher than north or south of the road. When

  13. Preliminary report on arsenic and heavy metals contents in soils and stream bed sediments of Cornia, Bruna and Alma coastal plains (Southern Tuscany

    Directory of Open Access Journals (Sweden)

    Dughetti F.

    2013-04-01

    Full Text Available The Department of Earth Sciences of University of Florence has conducted over the past ten years, numerous studies about the distribution of arsenic and heavy metals in mineralized areas of Tuscany, particularly in the Pecora basin. The area hosts several polymetallic ore bodies and a pyrite ore deposit. The studies have identified several geochemical anomalies (As, Cu, Pb, Zn… both in the areas which host the ore bodies and in the coastal plain (Scarlino Plain. To increase the knowledge concerning the distribution of As and heavy metals in other Tuscan coastal plains, research is under way in the alluvial plains of the Bruna, Cornia and Alma rivers. The preliminary analysis have focused on soils and stream sediments, to better understand the correlations between the downstream transport of rivers and the soils. We have made physic-chemical analysis, particle size analysis, mineralogical analysis for X-ray powder diffraction, chemical analysis for the determination of major element (X-ray Fluorescence and for the determination of 35 minor elements and traces (AAS and ICP.Preliminary data show high concentrations of several elements (As, Zn, Co…. The concentrations of these elements in soils and stream bed sediments are not always consistent; in particular we have found higher concentrations in soils than in stream bed sediments in Cornia Plain, while the opposite happens in the Bruna basin. Therefore the natural processes of rocks weathering does not seem to have affected uniformly. The distribution of As and heavy metals in soils and stream bed sediments of the all three basins of interest are still under investigation.

  14. Stream sediments analysis for geochemical mapping of Romagna Apennines (Northern Italy): monitoring and management tool of environmental resources at various scales

    OpenAIRE

    Lancianese, Valerio

    2014-01-01

    Geochemical mapping is a valuable tool for the control of territory that can be used not only in the identification of mineral resources and geological, agricultural and forestry studies but also in the monitoring of natural resources by giving solutions to environmental and economic problems. Stream sediments are widely used in the sampling campaigns carried out by the world's governments and research groups for their characteristics of broad representativeness of rocks and soils, for ease o...

  15. Relation between Streaming Potential and Streaming Electrification Generated by Streaming of Water through a Sandwich-type Cell

    OpenAIRE

    Maruyama, Kazunori; Nikaido, Mitsuru; Hara, Yoshinori; Tanizaki, Yoshie

    2012-01-01

    Both streaming potential and accumulated charge of water flowed out were measured simultaneously using a sandwich-type cell. The voltages generated in divided sections along flow direction satisfied additivity. The sign of streaming potential agreed with that of streaming electrification. The relation between streaming potential and streaming electrification was explained from a viewpoint of electrical double layer in glass-water interface.

  16. ADAPTIVE STREAMING OVER HTTP (DASH UNTUK APLIKASI VIDEO STREAMING

    Directory of Open Access Journals (Sweden)

    I Made Oka Widyantara

    2015-12-01

    Full Text Available This paper aims to analyze Internet-based streaming video service in the communication media with variable bit rates. The proposed scheme on Dynamic Adaptive Streaming over HTTP (DASH using the internet network that adapts to the protocol Hyper Text Transfer Protocol (HTTP. DASH technology allows a video in the video segmentation into several packages that will distreamingkan. DASH initial stage is to compress the video source to lower the bit rate video codec uses H.26. Video compressed further in the segmentation using MP4Box generates streaming packets with the specified duration. These packages are assembled into packets in a streaming media format Presentation Description (MPD or known as MPEG-DASH. Streaming video format MPEG-DASH run on a platform with the player bitdash teritegrasi bitcoin. With this scheme, the video will have several variants of the bit rates that gave rise to the concept of scalability of streaming video services on the client side. The main target of the mechanism is smooth the MPEG-DASH streaming video display on the client. The simulation results show that the scheme based scalable video streaming MPEG-DASH able to improve the quality of image display on the client side, where the procedure bufering videos can be made constant and fine for the duration of video views

  17. Analyzing indicators of stream health for Minnesota streams

    Science.gov (United States)

    Singh, U.; Kocian, M.; Wilson, B.; Bolton, A.; Nieber, J.; Vondracek, B.; Perry, J.; Magner, J.

    2005-01-01

    Recent research has emphasized the importance of using physical, chemical, and biological indicators of stream health for diagnosing impaired watersheds and their receiving water bodies. A multidisciplinary team at the University of Minnesota is carrying out research to develop a stream classification system for Total Maximum Daily Load (TMDL) assessment. Funding for this research is provided by the United States Environmental Protection Agency and the Minnesota Pollution Control Agency. One objective of the research study involves investigating the relationships between indicators of stream health and localized stream characteristics. Measured data from Minnesota streams collected by various government and non-government agencies and research institutions have been obtained for the research study. Innovative Geographic Information Systems tools developed by the Environmental Science Research Institute and the University of Texas are being utilized to combine and organize the data. Simple linear relationships between index of biological integrity (IBI) and channel slope, two-year stream flow, and drainage area are presented for the Redwood River and the Snake River Basins. Results suggest that more rigorous techniques are needed to successfully capture trends in IBI scores. Additional analyses will be done using multiple regression, principal component analysis, and clustering techniques. Uncovering key independent variables and understanding how they fit together to influence stream health are critical in the development of a stream classification for TMDL assessment.

  18. Spatial and Temporal Evolution of Stream Bedforms

    Science.gov (United States)

    Palmsten, M. L.; Kozarek, J. L.; Calantoni, J.; Kooney, T.; Holland, K.

    2011-12-01

    Streams are complex, dynamic environments that experience significant changes to the bathymetry over the course of hours when sediments are mobilized. Understanding the evolution of stream bed morphology is essential for a broad range of practical purposes including: assessing habitat for fish and forecasting the transport of sediments, nutrients, and pollutants. The objective of this work is to quantify bedform migration at a meander bend in a near-prototype scale laboratory stream and ultimately develop a dataset for comparison with sediment transport models. The spatial and temporal evolution of bedforms was observed at the University of Minnesota's St. Anthony Falls Stream Laboratory. The Outdoor Stream Lab (OSL) is a sandy (D50 = 0.7 mm) , meandering channel approximately 40 m in length 2.7 m in width, and 0.3 m in depth. Observations were made at overbank flow of 284 L/s. Color cameras were positioned at 5 m and 2 m above a meander bend and images were collected at a rate of 7.5 Hz as bedforms migrated through the field of view. Upstream of the meander bend, bedforms were nearly linear and migrated at 0.5 cm/s, while downstream of the bend, bedforms became extremely nonlinear in form and appeared nearly stationary. Images were rectified and post-processed to extract bedform dimensions as well as migration rate. The remotely sensed migration rates were compared with in situ measurements collected using sonar to map bedforms during the experiment.

  19. The Impact of a Check Dam on Groundwater Recharge and Sedimentation in an Ephemeral Stream

    Directory of Open Access Journals (Sweden)

    Hakan Djuma

    2017-10-01

    Full Text Available Despite the widespread presence of groundwater recharge check dams, there are few studies that quantify their functionality. The objectives of this study are (i to assess groundwater recharge in an ephemeral river with and without a check dam and (ii to assess sediment build-up in the check-dam reservoir. Field campaigns were carried out to measure water flow, water depth, and check-dam topography to establish water volume, evaporation, outflow, and recharge relations, as well as sediment build-up. To quantify the groundwater recharge, a water-balance approach was applied at two locations: at the check dam reservoir area and at an 11 km long natural stretch of the river upstream. Prediction intervals were computed to assess the uncertainties of the results. During the four years of operation, the check dam (storage capacity of 25,000 m3 recharged the aquifer with an average of 3.1 million m3 of the 10.4 million m3 year−1 of streamflow (30%. The lower and upper uncertainty limits of the check dam recharge were 0.1 and 9.6 million m3 year−1, respectively. Recharge from the upstream stretch was 1.5 million m3 year−1. These results indicate that check dams are valuable structures for increasing groundwater resources in semi-arid regions.

  20. Modelling erosion and catchment's sediment exports based on erosion plot's measurements using the STREAM model. Application to the Rheraya catchment, High Atlas, Morocco.

    Science.gov (United States)

    Simonneaux, V.; Deschamps, C.; Cheggour, A.; Le Bissonnais, Y.

    2009-04-01

    Keywords: erosion, modelling, erosion plots, sediment exportation, STREAM The Rheraya watershed (225 km2) is located in a semi-arid climat, in the High Atlas of Morocco. The land cover includes mainly degraded rangelands on the slopes, and some irrigated crops in the valleys. The average annual rainfall ranges between 300 and 500 mm depending on the site location. Six erosion plots of about 150 m2, located on various soil and land cover conditions were measured during four years. The observations showed very rare runoff events in the main part of the watershed, and producing a low sediment load (between 0.015 and 2.5 t/ha/year). Conversely, runoff was much more frequent on silty badlands, producing about 95% of the watershed sediment (350 t/ha/year) despite their area was only 1% of the watershed. The resulting average erosion over the watershed was about 3-4 t/ha/year, which is of the same order than the mean sediment exportation at the outlet, indicating a sediment delivery ratio around 1. STREAM is a semi empirical distributed erosion model initially designed for agricultural landscapes, taking into account as the main drivers of erosion, the vegetation cover, the soil surface states and the soil roughness. These surface characteristics are input by the user for each pixel, allowing the computing of the infiltration capacity and the runoff turbidity. STREAM works for single rain events, and uses a simple hortonian hypothesis for runoff generation for each pixel, which is subsequently routed down slope using a DEM. The adaptation of this model to the very different context of the Rheraya catchment, with mostly rangelands instead of crops, led us to identify three new drivers of soil infiltration and turbidity, namely the soil type, the soil protection by vegetation or stones, and the soil conservation practices. Infiltration and turbidity for each landscape unit were quantified based on the in situ erosion plot measurements. The results of STREAM simulations for

  1. Influence of large wood on channel morphology and sediment storage in headwater mountain streams, Fraser Experimental Forest, Colorado

    Science.gov (United States)

    Sandra E. Ryan; Erica L. Bishop; J. Michael Daniels

    2014-01-01

    Large fallen wood can have a significant impact on channel form and process in forested mountain streams. In this study, four small channels on the Fraser Experimental Forest near Fraser, Colorado, USA, were surveyed for channel geometries and large wood loading, including the size, source, and characteristics of individual pieces. The study is part of a larger effort...

  2. National Geochemical Atlas: The geochemical landscape of the conterminous United States derived from stream sediment and other solid sample media analyzed by the National Uranium Resource Evaluation (NURE) Program

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A subset of the National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) data were used to produce a set of map images...

  3. What Can Hierarchies Do for Data Streams?

    DEFF Research Database (Denmark)

    Yin, Xuepeng; Pedersen, Torben Bach

    Much effort has been put into building data streams management systems for querying data streams. Here, data streams have been viewed as a flow of low-level data items, e.g., sensor readings or IP packet data. Stream query languages have mostly been SQL-based, with the STREAM and Telegraph...

  4. We All Stream for Video

    Science.gov (United States)

    Technology & Learning, 2008

    2008-01-01

    More than ever, teachers are using digital video to enhance their lessons. In fact, the number of schools using video streaming increased from 30 percent to 45 percent between 2004 and 2006, according to Market Data Retrieval. Why the popularity? For starters, video-streaming products are easy to use. They allow teachers to punctuate lessons with…

  5. Save Our Streams and Waterways.

    Science.gov (United States)

    Indiana State Dept. of Education, Indianapolis. Center for School Improvement and Performance.

    Protection of existing water supplies is critical to ensuring good health for people and animals alike. This program is aligned with the Izaak Walton League of American's Save Our Streams program which is based on the concept that students can greatly improve the quality of a nearby stream, pond, or river by regular visits and monitoring. The…

  6. Pilot-Streaming: Design Considerations for a Stream Processing Framework for High-Performance Computing

    OpenAIRE

    Andre Luckow; Peter Kasson; Shantenu Jha

    2016-01-01

    This White Paper (submitted to STREAM 2016) identifies an approach to integrate streaming data with HPC resources. The paper outlines the design of Pilot-Streaming, which extends the concept of Pilot-abstraction to streaming real-time data.

  7. Guidelines and Procedures for Computing Time-Series Suspended-Sediment Concentrations and Loads from In-Stream Turbidity-Sensor and Streamflow Data

    Science.gov (United States)

    Rasmussen, Patrick P.; Gray, John R.; Glysson, G. Douglas; Ziegler, Andrew C.

    2009-01-01

    In-stream continuous turbidity and streamflow data, calibrated with measured suspended-sediment concentration data, can be used to compute a time series of suspended-sediment concentration and load at a stream site. Development of a simple linear (ordinary least squares) regression model for computing suspended-sediment concentrations from instantaneous turbidity data is the first step in the computation process. If the model standard percentage error (MSPE) of the simple linear regression model meets a minimum criterion, this model should be used to compute a time series of suspended-sediment concentrations. Otherwise, a multiple linear regression model using paired instantaneous turbidity and streamflow data is developed and compared to the simple regression model. If the inclusion of the streamflow variable proves to be statistically significant and the uncertainty associated with the multiple regression model results in an improvement over that for the simple linear model, the turbidity-streamflow multiple linear regression model should be used to compute a suspended-sediment concentration time series. The computed concentration time series is subsequently used with its paired streamflow time series to compute suspended-sediment loads by standard U.S. Geological Survey techniques. Once an acceptable regression model is developed, it can be used to compute suspended-sediment concentration beyond the period of record used in model development with proper ongoing collection and analysis of calibration samples. Regression models to compute suspended-sediment concentrations are generally site specific and should never be considered static, but they represent a set period in a continually dynamic system in which additional data will help verify any change in sediment load, type, and source.

  8. Subglacial sediment provenance and transport in West Antarctica from micropaleontologic analysis of Subglacial Lake Whillans and the upstream sectors of the Whillans and Kamb ice streams

    Science.gov (United States)

    Scherer, Reed; Coenen, Jason; Warny, Sophie

    2014-05-01

    The WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) project recovered sediment cores from Subglacial Lake Whillans (SLW) in West Antarctica. We report preliminary micropaleontological analyses of SLW sediments, augmented by analysis of sediments previously recovered from beneath the upstream camps of the Whillans Ice Stream (WIS) and Kamb Ice Stream (KIS). Microfossils in these sediments (notably diatoms, sponge spicules, and organic-walled palynomorphs), include information regarding sediment transport, subglacial physical processes and ice sheet history. Absolute abundance (particles per gram dry sediment) of identifiable diatoms and diatom fragments in different size classes were calculated to compare and contrast each environment. Sponge spicules are being analyzed for taphonomic effects from subglacial transport and shearing. Palynomorphs are analyzed for abundance, diversity, and source rock ages. In SLW the upper 30 cm is softer and more water-rich than the underlying sediments. However, no statistically significant variation in microfossil and fragment abundance or taphonomy is noted in these diamictons, which is in agreement with the stratigraphic homogeneity evident from geochemical and geological analyses performed to date. SLW contains 1.52x106 to 1.13x107 diatom fragments per gram, compared with 6.43x106 to 4.63x108 at upstream WIS and 6.13 107 to 1.58x108 at KIS. Whole diatoms are orders of magnitude lower in concentration. Low abundance and poor preservation of diatoms and spicules at SLW suggests relatively long distance transport from their marine sediment source, with evidence of high shear strain, following the subglacial shearing index of Scherer et al. (2004). Upper Miocene diatoms dominate all samples analyzed, though older and younger diatoms are noted as well. The WIS samples exhibit the highest diversity of diatoms, including Paleogene freshwater diatoms. KIS sediments have the highest abundance of whole diatoms, but they

  9. STREAM: A First Programming Process

    DEFF Research Database (Denmark)

    Caspersen, Michael Edelgaard; Kölling, Michael

    2009-01-01

    to derive a programming process, STREAM, designed specifically for novices. STREAM is a carefully down-scaled version of a full and rich agile software engineering process particularly suited for novices learning object-oriented programming. In using it we hope to achieve two things: to help novice...... programmers learn faster and better while at the same time laying the foundation for a more thorough treatment of more advanced aspects of software engineering. In this article, two examples demonstrate the application of STREAM. The STREAM process has been taught in the introductory programming courses...... at our universities for the past three years and the results are very encouraging. We report on a small, preliminary study evaluating the learning outcome of teaching STREAM. The study indicates a positive effect on the development of students’ process competences....

  10. Occurrence and concentrations of selected trace elements and halogenated organic compounds in stream sediments and potential sources of polychlorinated biphenyls, Leon Creek, San Antonio, Texas, 2012–14

    Science.gov (United States)

    Wilson, Jennifer T.

    2016-06-23

    The Texas Department of State Health Services issued fish consumption advisories in 2003 and 2010 for Leon Creek in San Antonio, Texas, based on elevated concentrations of polychlorinated biphenyls (PCBs) in fish tissues. The U.S. Geological Survey (USGS) measured elevated PCB concentrations in stream-sediment samples collected during 2007–9 from Leon Creek at Lackland Air Force Base (now known as Joint Base San Antonio-Lackland; the sampling site at this base is hereinafter referred to as the “Joint Base site”) and sites on Leon Creek downstream from the base. This report describes the occurrence and concentrations of selected trace elements and halogenated organic compounds (pesticides, flame retardants, and PCBs) and potential sources of PCBs in stream-sediment samples collected from four sites on Leon Creek during 2012–14. In downstream order, sediment samples were collected from Leon Creek at northwest Interstate Highway 410 (Loop 410), Rodriguez Park, Morey Road, and Joint Base. The USGS periodically collected streambed-sediment samples during low flow and suspended-sediment samples during high flow.

  11. The impact of anthropogenic factors on the occurrence of molybdenum in stream and river sediments of central Upper Silesia (Southern Poland

    Directory of Open Access Journals (Sweden)

    Pasieczna Anna

    2017-12-01

    Full Text Available In our study, a detailed survey was conducted with the aim to determine the distribution and possible anthropogenic sources of molybdenum in river and stream sediments in the central Upper Silesian Industrial Region (Southern Poland, where for many years, iron and zinc smelters as well as coking and thermal power plants were operating. At the same time, this has also been a residential area with the highest population density in the country. Sediments (1397 samples in total were collected from rivers and streams, and analysed for the content of molybdenum and 22 other elements. ICP-AES and CV-AAS methods were applied for the determination of the content of elements. The studies revealed molybdenum content in the range of 5 mg·kg−1. The spatial distribution of molybdenum demonstrated by the geochemical map has indicated that the principal factor determining its content in sediments is the discharge of wastewater from steelworks and their slag heaps. Another source of this element in sediments has been the waste of the historical mining of zinc ore and metallurgy of this metal. Additionally, molybdenum migration from landfills of power plants, coal combustion and Mo emission to the atmosphere and dust fall-out have been significant inputs of Mo pollution to the sediments.

  12. Water and Streambed Sediment Quality, and Ecotoxicology of a Stream along the Blue Ridge Parkway, Adjacent to a Closed Landfill, near Roanoke, Virginia: 1999

    Science.gov (United States)

    Ebner, Donna Belval; Cherry, Donald S.; Currie, Rebecca J.

    2004-01-01

    A study was done of the effects of a closed landfill on the quality of water and streambed sediment and the benthic macroinvertebrate community of an unnamed stream and its tributary that flow through Blue Ridge Parkway lands in west-central Virginia. The primary water source for the tributary is a 4-inch polyvinyl chloride (PVC) pipe that protrudes from the slope at the base of the embankment bordering the landfill. An unusual expanse of precipitate was observed in the stream near the PVC pipe. Stream discharge was measured and water and streambed sediment samples were collected at a nearby reference site and at three sites downstream of the landfill in April and September 1999. Water samples were analyzed for major ions, nitrate, total and dissolved metals, total dissolved solids, total organic carbon, and volatile and semivolatile organic compounds, including organochlorine pesticides and polychlorinated biphenyls (PCBs). Streambed sediment samples were analyzed for total metals, total organic carbon, percent moisture, and volatile and semivolatile organic compounds, including organochlorine pesticides and PCBs. The benthic macroinvertebrate community within the stream channel also was sampled at the four chemical sampling sites and at one additional site in April and September. Each of the five sites was assessed for physical habitat quality. Water collected periodically at the PVC pipe discharge between November 1998 and November 1999 was used to conduct 48-hour acute and 7-day chronic toxicity tests using selected laboratory test organisms. Two 10-day chronic toxicity tests of streambed sediments collected near the discharge pipe also were conducted. Analyses showed that organic and inorganic constituents in water from beneath the landfill were discharged into the sampled tributary. In April, 79 percent of inorganic constituents detected in water had their highest concentrations at the site closest to the landfill; at the same site, 59 percent of inorganic

  13. Multifractal interpolation and spectrum-area fractal modeling of stream sediment geochemical data: Implications for mapping exploration targets

    Science.gov (United States)

    Parsa, Mohammad; Maghsoudi, Abbas; Yousefi, Mahyar; Carranza, Emmanuel John M.

    2017-04-01

    The spectrum-area (S-A) fractal model is a powerful tool for decomposition of complex anomaly patterns of gridded geochemical data. Ordinary moving average interpolation techniques are commonly being used for gridding geochemical data; however, these methods suffer from two major drawbacks of (1) ignoring the locally high values and (2) smoothing the interpolated surface. Multifractal moving average interpolation methods have been developed to overcome the shortcomings of ordinary moving average methods. This study seeks to compare two sets of multifractal and ordinary gridded geochemical data using success rate curves and applies the S-A fractal model to decompose anomalous geochemical patterns. A set of stream sediment geochemical data in Ahar area, NW Iran, was used as a case study. Then, a mineralization-related multi-element geochemical signature was gridded by ordinary and multifractal approaches and considered for further analyses. The S-A fractal method was applied to decompose anomaly and background components of the resultant multi-element geochemical signature. Exploration targets were delimited and further evaluated using two bivariate statistical procedures of Student's t-value and normalized density index. The results revealed that (a) application of multifractal gridded data enhances the predicting ability of geochemical signatures, (b) application of S-A fractal model on multifractal gridded data allows for superior discrimination of geochemical anomalies, and (c) the multi-element geochemical anomalies in the Ahar area related to porphyry-Cu deposits were properly delineated through sequence application of multifractal interpolation and S-A fractal model.

  14. Biological assessment and streambed-sediment chemistry of streams in the Indianapolis metropolitan area, Indiana, 2003–2008

    Science.gov (United States)

    Voelker, David C.

    2012-01-01

    During 2003–2008, the U.S. Geological Survey sampled 13 sites in the Indianapolis metropolitan area in Indiana for benthic invertebrates, fish communities, and streambed-sediment chemistry. Data from seven White River sites and six tributary sites complement surface-water chemistry data collected by the Indianapolis Department of Public Works. The information is being used to assess changes in water quality in conjunction with the City's programs to reduce combined sewer overflows and other point and nonpoint sources of pollution in the Indianapolis area. During the study, 233 benthic-invertebrate taxa were identified from which the Ephemeroptera, Plecoptera, and Trichoptera (EPT) Index, the Hilsenhoff Biotic Index (HBI), and the Invertebrate Community Index (ICI) were calculated. EPT index scores ranged from 2 to 16 on the White River and from 2 to 17 on the tributaries. EPT index scores indicate that these pollution-intolerant taxa are more prevalent upstream from and away from the combined-sewer areas of Indianapolis. HBI scores from sites on the White River ranged from 4.67 (good) to 9.55 (very poor), whereas on the tributaries, scores ranged from 4.21 (very good) to 8.14 (poor). Lower HBI scores suggest that less organic pollution was present and, like the EPT scores, indicate better conditions where combined-sewer overflows (CSOs) are not present. Similarly, ICI scores indicated better conditions upstream from the CSO outfalls on the White River. White River scores ranged from 12 to 46, where higher ICI scores indicate better conditions in the benthic-invertebrate community. ICI scores at the tributary sites ranged from 12 to 52, with the highest scores on streams without CSOs.

  15. Stream-profile analysis and stream-gradient index

    Science.gov (United States)

    Hack, John T.

    1973-01-01

    The generally regular three-dimensional geometry of drainage networks is the basis for a simple method of terrain analysis providing clues to bedrock conditions and other factors that determine topographic forms. On a reach of any stream, a gradient-index value can be obtained which allows meaningful comparisons of channel slope on streams of different sizes. The index is believed to reflect stream power or competence and is simply the product of the channel slope at a point and channel length measured along the longest stream above the pointwhere the calculation is made. In an adjusted topography, changes in gradient-index values along a stream generally correspond to differences in bedrock or introduced load. In any landscape the gradient index of a stream is related to total relief and stream regimen. Thus, climate, tectonic events, and geomorphic history must be considered in using the gradient index. Gradient-index values can be obtained quickly by simple measurements on topographic maps, or they can be obtained by more sophisticated photogrammetric measurements that involve simple computer calculations from x, y, z coordinates.

  16. Major Kansas Perennial Streams : 1961 and 2009

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Map of major perennial streams in Kansas for the years 1961 and 2009. The map shows a decrease in streams regarded as perennial in 1961, compared to stream regarded...

  17. Stream Habitat Reach Summary - NCWAP [ds158

    Data.gov (United States)

    California Department of Resources — The Stream Habitat - NCWAP - Reach Summary [ds158] shapefile contains in-stream habitat survey data summarized to the stream reach level. It is a derivative of the...

  18. Electronic Eye: Streaming Video On-Demand.

    Science.gov (United States)

    Meulen, Kathleen

    2002-01-01

    Discusses the use of on-demand streaming video in school libraries. Explains how streaming works, considers advantages and technical issues, and describes products from three companies that are pioneering streaming in the educational video market. (LRW)

  19. Percent Forest Adjacent to Streams (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  20. Percent Agriculture Adjacent to Streams (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The type of vegetation along a stream influences the water quality in the stream. Intact buffer strips of natural vegetation along streams tend to intercept...

  1. CHNTRN: a CHaNnel TRaNsport model for simulating sediment and chemical distribution in a stream/river network

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, G.T.

    1983-09-01

    This report presents the development of a CHaNnel TRaNsport model for simulating sediment and chemical distribution in a stream/river network. A particular feature of the model is its capability to deal with the network system that may consist of any number of joined and branched streams/rivers of comparable size. The model employs a numerical method - an integrated compartment method (ICM) - which greatly facilitates the setup of the matrix equation for the discrete field approximating the corresponding continuous field. Most of the possible boundary conditions that may be anticipated in real-world problems are considered. These include junctions, prescribed concentration, prescribed dispersive flux, and prescribed total flux. The model is applied to two case studies: (1) a single river and (2) a five-segment river in a watershed. Results indicate that the model can realistically simulate the behavior of the sediment and chemical variations in a stream/river network. 11 references, 10 figures, 3 tables.

  2. Integrated assessment of sources, chemical stressors and stream quality along a groundwater fed stream system

    Science.gov (United States)

    Løgstrup Bjerg, Poul; Sonne, Anne T.; Rønde, Vinni; McKnight, Ursula S.

    2016-04-01

    Streams are impacted by significant contamination at the catchment scale, as they are often locations of multiple chemical stressor inputs. The European Water Framework Directive requires EU member states to ensure good chemical and ecological status of surface water bodies by 2027. This requires monitoring of stream water quality, comparison with environmental quality standards (EQS) and assessment of ecological status. However, the achievement of good status of stream water also requires a strong focus on contaminant sources, pathways and links to stream water impacts, so source management and remedial measures can be implemented. Fate and impacts of different contaminant groups are governed by different processes and are dependent on the origin (geogenic, anthropogenic), source type (point or diffuse) and pathway of the contaminant. To address this issue, we identified contaminant sources and chemical stressors on a groundwater-fed stream to quantify the contaminant discharges, link the chemical impact and stream water quality and assess the main chemical risk drivers in the stream system potentially driving ecological impact. The study was conducted in the 8 m wide Grindsted stream (Denmark) along a 16 km stream stretch that is potentially impacted by two contaminated sites (Grindsted Factory site, Grindsted Landfill), fish farms, waste water discharges, and diffuse sources from agriculture and urban areas. Water samples from the stream and the hyporheic zone as well as bed sediment samples were collected during three campaigns in 2012 and 2014. Data for xenobiotic organic groundwater contaminants, pesticides, heavy metals, general water chemistry, physical conditions and stream flow were collected. The measured chemical concentrations were converted to toxic units (TU) based on the 48h acute toxicity tests with D. magna. The results show a substantial impact of the Grindsted Factory site at a specific stretch of the stream. The groundwater plume caused

  3. Streaming patterns in Faraday waves

    CERN Document Server

    Périnet, Nicolas; Urra, Héctor; Mujica, Nicolás; Gordillo, Leonardo

    2016-01-01

    Waves patterns in the Faraday instability have been studied for decades. Besides the rich dynamics that can be observed on the waves at the interface, Faraday waves hide beneath them an elusive range of flow patterns --or streaming patterns-- which have not been studied in detail until now. The streaming patterns are responsible for a net circulation in the flow which are reminiscent of convection cells. In this article, we analyse these streaming flows by conducting experiments in a Faraday-wave setup. To visualize the flows, tracers are used to generate both trajectory maps and to probe the streaming velocity field via Particle Image Velocimetry (PIV). We identify three types of patterns and experimentally show that identical Faraday waves can mask streaming patterns that are qualitatively very different. Next we propose a three-dimensional model that explains streaming flows in quasi-inviscid fluids. We show that the streaming inside the fluid arises from a complex coupling between the bulk and the boundar...

  4. Environmental Risk Assessment Based on High-Resolution Spatial Maps of Potentially Toxic Elements Sampled on Stream Sediments of Santiago, Cape Verde

    Directory of Open Access Journals (Sweden)

    Marina M. S. Cabral Pinto

    2014-10-01

    Full Text Available Geochemical mapping is the base knowledge to identify the regions of the planet with critical contents of potentially toxic elements from either natural or anthropogenic sources. Sediments, soils and waters are the vehicles which link the inorganic environment to life through the supply of essential macro and micro nutrients. The chemical composition of surface geological materials may cause metabolic changes which may favor the occurrence of endemic diseases in humans. In order to better understand the relationships between environmental geochemistry and public health, we present environmental risk maps of some harmful elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn in the stream sediments of Santiago, Cape Verde, identifying the potentially harmful areas in this island. The Estimated Background Values (EBV of Cd, Co, Cr, Ni and V were found to be above the Canadian guidelines for any type of use of stream sediments and also above the target values of the Dutch and United States guidelines. The Probably Effect Concentrations (PEC, above which harmful effects are likely in sediment dwelling organisms, were found for Cr and Ni. Some associations between the geological formations of the island and the composition of stream sediments were identified and confirmed by descriptive statistics and by Principal Component Analysis (PCA. The EBV spatial distribution of the metals and the results of PCA allowed us to establish relationships between the EBV maps and the geological formations. The first two PCA modes indicate that heavy metals in Santiago stream sediments are mainly originated from weathering of underlying bedrocks. The first metal association (Co, V, Cr, and Mn; first PCA mode consists of elements enriched in basic rocks and compatible elements. The second association of variables (Zn and Cd as opposed to Ni; second PCA mode appears to be strongly controlled by the composition of alkaline volcanic rocks and pyroclastic rocks. So, the

  5. Spring 5 & reactive streams

    CERN Document Server

    CERN. Geneva; Clozel, Brian

    2017-01-01

    Spring is a framework widely used by the world-wide Java community, and it is also extensively used at CERN. The accelerator control system is constituted of 10 million lines of Java code, spread across more than 1000 projects (jars) developed by 160 software engineers. Around half of this (all server-side Java code) is based on the Spring framework. Warning: the speakers will assume that people attending the seminar are familiar with Java and Spring’s basic concepts. Spring 5.0 and Spring Boot 2.0 updates (45 min) This talk will cover the big ticket items in the 5.0 release of Spring (including Kotlin support, @Nullable and JDK9) and provide an update on Spring Boot 2.0, which is scheduled for the end of the year. Reactive Spring (1h) Spring Framework 5.0 has been released - and it now supports reactive applications in the Spring ecosystem. During this presentation, we'll talk about the reactive foundations of Spring Framework with the Reactor project and the reactive streams specification. We'll al...

  6. Knowledge discovery from data streams

    CERN Document Server

    Gama, Joao

    2010-01-01

    Since the beginning of the Internet age and the increased use of ubiquitous computing devices, the large volume and continuous flow of distributed data have imposed new constraints on the design of learning algorithms. Exploring how to extract knowledge structures from evolving and time-changing data, Knowledge Discovery from Data Streams presents a coherent overview of state-of-the-art research in learning from data streams.The book covers the fundamentals that are imperative to understanding data streams and describes important applications, such as TCP/IP traffic, GPS data, sensor networks,

  7. Occurrence, distribution, and volume of metals-contaminated sediment of selected streams draining the Tri-State Mining District, Missouri, Oklahoma, and Kansas, 2011–12

    Science.gov (United States)

    Smith, D. Charlie

    2016-12-14

    Lead and zinc were mined in the Tri-State Mining District (TSMD) of southwest Missouri, northeast Oklahoma, and southeast Kansas for more than 100 years. The effects of mining on the landscape are still evident, nearly 50 years after the last mine ceased operation. The legacies of mining are the mine waste and discharge of groundwater from underground mines. The mine-waste piles and underground mines are continuous sources of trace metals (primarily lead, zinc, and cadmium) to the streams that drain the TSMD. Many previous studies characterized the horizontal extent of mine-waste contamination in streams but little information exists on the depth of mine-waste contamination in these streams. Characterizing the vertical extent of contamination is difficult because of the large amount of coarse-grained material, ranging from coarse gravel to boulders, within channel sediment. The U.S. Geological Survey, in cooperation with U.S. Fish and Wildlife service, collected channel-sediment samples at depth for subsequent analyses that would allow attainment of the following goals: (1) determination of the relation between concentration and depth for lead, zinc and cadmium in channel sediments and flood-plain sediments, and (2) determination of the volume of gravel-bar sediment from the surface to the maximum depth with concentrations of these metals that exceeded sediment-quality guidelines. For the purpose of this report, volume of gravel-bar sediment is considered to be distributed in two forms, gravel bars and the wetted channel, and this study focused on gravel bars. Concentrations of lead, zinc, and cadmium in samples were compared to the consensus probable effects concentration (CPEC) and Tri-State Mining District specific probable effects concentration (TPEC) sediment-quality guidelines.During the study, more than 700 sediment samples were collected from borings at multiple sites, including gravel bars and flood plains, along Center Creek, Turkey Creek, Shoal Creek

  8. Re-Meandering of Lowland Streams

    DEFF Research Database (Denmark)

    Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

    2014-01-01

    and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled......We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats...... along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored...

  9. ATLAS Live: Collaborative Information Streams

    Science.gov (United States)

    Goldfarb, Steven; ATLAS Collaboration

    2011-12-01

    I report on a pilot project launched in 2010 focusing on facilitating communication and information exchange within the ATLAS Collaboration, through the combination of digital signage software and webcasting. The project, called ATLAS Live, implements video streams of information, ranging from detailed detector and data status to educational and outreach material. The content, including text, images, video and audio, is collected, visualised and scheduled using digital signage software. The system is robust and flexible, utilizing scripts to input data from remote sources, such as the CERN Document Server, Indico, or any available URL, and to integrate these sources into professional-quality streams, including text scrolling, transition effects, inter and intra-screen divisibility. Information is published via the encoding and webcasting of standard video streams, viewable on all common platforms, using a web browser or other common video tool. Authorisation is enforced at the level of the streaming and at the web portals, using the CERN SSO system.

  10. ATLAS Live: Collaborative Information Streams

    CERN Document Server

    Goldfarb, S; The ATLAS collaboration

    2011-01-01

    I report on a pilot project launched in 2010 focusing on facilitating communication and information exchange within the ATLAS Collaboration, through the combination of digital signage software and webcasting. The project, called ATLAS Live, implements video streams of information, ranging from detailed detector and data status to educational and outreach material. The content, including text, images, video and audio, is collected, visualised and scheduled using digital signage software. The system is robust and flexible, utilizing scripts to input data from remote sources, such as the CERN Document Server, Indico, or any available URL, and to integrate these sources into professional-quality streams, including text scrolling, transition effects, inter and intra-screen divisibility. Information is published via the encoding and webcasting of standard video streams, viewable on all common platforms, using a web browser or other common video tool. Authorisation is enforced at the level of the streaming and at th...

  11. Video streaming into the mainstream.

    Science.gov (United States)

    Garrison, W

    2001-12-01

    Changes in Internet technology are making possible the delivery of a richer mixture of media through data streaming. High-quality, dynamic content, such as video and audio, can be incorporated into Websites simply, flexibly and interactively. Technologies such as G3 mobile communication, ADSL, cable and satellites enable new ways of delivering medical services, information and learning. Systems such as Quicktime, Windows Media and Real Video provide reliable data streams as video-on-demand and users can tailor the experience to their own interests. The Learning Development Centre at the University of Portsmouth have used streaming technologies together with e-learning tools such as dynamic HTML, Flash, 3D objects and online assessment successfully to deliver on-line course content in economics and earth science. The Lifesign project--to develop, catalogue and stream health sciences media for teaching--is described and future medical applications are discussed.

  12. Cellular Subcompartments through Cytoplasmic Streaming.

    Science.gov (United States)

    Pieuchot, Laurent; Lai, Julian; Loh, Rachel Ann; Leong, Fong Yew; Chiam, Keng-Hwee; Stajich, Jason; Jedd, Gregory

    2015-08-24

    Cytoplasmic streaming occurs in diverse cell types, where it generally serves a transport function. Here, we examine streaming in multicellular fungal hyphae and identify an additional function wherein regimented streaming forms distinct cytoplasmic subcompartments. In the hypha, cytoplasm flows directionally from cell to cell through septal pores. Using live-cell imaging and computer simulations, we identify a flow pattern that produces vortices (eddies) on the upstream side of the septum. Nuclei can be immobilized in these microfluidic eddies, where they form multinucleate aggregates and accumulate foci of the HDA-2 histone deacetylase-associated factor, SPA-19. Pores experiencing flow degenerate in the absence of SPA-19, suggesting that eddy-trapped nuclei function to reinforce the septum. Together, our data show that eddies comprise a subcellular niche favoring nuclear differentiation and that subcompartments can be self-organized as a consequence of regimented cytoplasmic streaming. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. vysmaw: Fast visibility stream muncher

    Science.gov (United States)

    Pokorny, Martin; Law, Casey J.

    2017-10-01

    The vysmaw client library facilitates the development of code for processes to tap into the fast visibility stream on the National Radio Astronomy Observatory's Very Large Array correlator back-end InfiniBand network.

  14. Online Visual Analytics of Text Streams.

    Science.gov (United States)

    Liu, Shixia; Yin, Jialun; Wang, Xiting; Cui, Weiwei; Cao, Kelei; Pei, Jian

    2016-11-01

    We present an online visual analytics approach to helping users explore and understand hierarchical topic evolution in high-volume text streams. The key idea behind this approach is to identify representative topics in incoming documents and align them with the existing representative topics that they immediately follow (in time). To this end, we learn a set of streaming tree cuts from topic trees based on user-selected focus nodes. A dynamic Bayesian network model has been developed to derive the tree cuts in the incoming topic trees to balance the fitness of each tree cut and the smoothness between adjacent tree cuts. By connecting the corresponding topics at different times, we are able to provide an overview of the evolving hierarchical topics. A sedimentation-based visualization has been designed to enable the interactive analysis of streaming text data from global patterns to local details. We evaluated our method on real-world datasets and the results are generally favorable.

  15. Design Automation for Streaming Systems

    Science.gov (United States)

    2005-12-16

    Verilog back-end emits them as black boxes. 3.6 System Composition We synthesize a system as a composition of stream-connected pages, where a page...Figure 6.5 shows a sample state flow graph for clustering. Each node denotes a state and its action. Each black 242 Chapter 6. Streaming Programmable...Bilsen, Marc Engels, Rudy Lauwereins, and Jean Peper - straete. Cyclo-static dataflow. IEEE Transactions on Signal Processing, 44(2):397– 408, February

  16. Water quality, organic chemistry of sediment, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee

    Science.gov (United States)

    Bradfield, A.D.; Flexner, N.M.; Webster, D.A.

    1993-01-01

    An investigation of water quality, organic sediment chemistry, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee, was conducted during December 1990. The study was designed to assess the extent of possible contamination of water and biota in the streams from creosote-related discharge originating at this Superfund site. Central Creek, adjacent to the plant, had degraded water quality and biological conditions. Water samples from the most downstream station on Central Creek contained 30 micrograms per liter of pentachlorophenol, which exceeds the State's criterion maximum concentrations of 9 micrograms per liter for fish and aquatic life. Bottom-sediment samples from stations on Central Creek contained concentrations of acenaphthene, napthalene, and phenanthrene ranging from 1,400 to 2,500 micrograms per kilogram. Chronic or acute toxicity resulted during laboratory experiments using test organisms exposed to creosote-related contaminants. Sediment elutriate samples from Central Creek caused slightly to highly toxic effects on Ceriodaphnia dubia. Pimephales promelas, and Photobacterium phosphoreum. Fish-tissue samples from this station contained concentrations of naphthalene. dibenzofuran, fluorene, and phenanthrene ranging from 1.5 to 3.9 micrograms per kilogram Blue-green algae at this station represented about 79 percent of the organisms counted, whereas diatoms accounted for only 11 percent. Benthic invertebrate and fish samples from Central Creek had low diversity and density. Sediment samples from a station on the South Fork Forked Deer River downstream from its confluence with Central Creek contained concentrations of acenaphthene, anthracene, chrysene, fluoranthene, fluorene, pyrere, and phenanthrene ranging from 2,800 to 69,000 micrograms per kilogram. Sediment elutriate samples using water as elutriate from this station contained concentrations of extractable organic compounds ranging from an estimated

  17. The application of stream sediment and heavy mineral exploratory methods on evaluation of mineralization potential in Soltan Meydan basalts, north of Shahroud

    Directory of Open Access Journals (Sweden)

    Mehdi Hashemi Gahrouei

    2012-10-01

    Full Text Available In order to assess the potential of copper mineralization and its associated elements in Soltan Meydan basaltic formation situated in the north of Shahrud, the method of stream sediment and heavy mineral has been used. To achieve this aim, totally 68 samples of sediments (-80 mesh in particle size and 6 samples of heavy minerals (-20 mesh in particle size have been collected in an optimized network of sampling. Stream sediment samples have been analyzed in for Cu, Pb, Zn, Co, Mn, Fe and Ni. Statistical processing of geochemical data resulted in identifying of elements with anomaly values, discrimination between anomalous and background values, and also assigning the inter-element relationships. Among the elements, Cu and Ni show first and second order anomalies in the samples. Results show that Fe, Pb, and Zn are associated together and also indicate positive correlation with Co and Mn, strongly (r≥0.5. The study of heavy mineral samples indicates the presence of magnetite, hematite, goethite, limonite, pyrite, oxidized pyrite, ocher, barite, apatite, rutile, zircon, nigrine, anatase, sphene, leucoxene, gold and ferromagnesian silicates. Statistical processing of heavy mineral data shows the association of Au, Ti, and Fe-oxides. The results of geochemical data processing and their integration with results of distribution pattern of fractures indicates good correlation between geochemical anomalies and highly fractured regions, as a result promising area for Cu and Ti mineralization has been identified and suggested for performing of further exploration.

  18. Impact of Stream Metabolism on Nitrate Concentrations in an Urban Stream

    Science.gov (United States)

    Ledford, S. H.; Lautz, L.; Vidon, P.; Stella, J. C.

    2016-12-01

    Nitrate dynamics in urban streams differ from many natural streams due to unique water inputs (e.g., wastewater, runoff from impervious cover) and often limited hyporheic exchange. Biogeochemical processes affecting N concentration in streams also differ from more natural systems as in-stream assimilation may be enhanced by biota due to increased primary productivity, while denitrification in stream sediments may be reduced owing to limited carbon input and reduced hyporheic exchange. This study investigates NO3 dynamics in a first-order stream in Syracuse, NY, which has urbanized headwaters with minimal stream-groundwater interaction and no riparian cover, and a natural downstream section, with meandering channel morphology and mature vegetation. Seasonal water sampling, NO3 injection tests and isotopic analysis of NO3 were performed to identify sources and sinks throughout the year, along with measures of filamentous algae density. The urban headwater reach has a maximum NO3 concentration of 0.2 mg N/L in the spring through fall, with a minimum uptake length of 900 m, no canopy cover, and high algae mat density. NO3 increases to 0.8 mg N/L beginning in the fall leaf-off period and continuing into winter in the urban reach. The downstream natural reach has NO3 concentrations between 0.6 and 1.2 mg N/L from December to September but dropped below 0.4 mg N/L in October and November during leaf-off. This section of the stream has almost 100% canopy cover during the summer and low algae mat density. Low NO3 concentrations in the urban reach (open canopy), combined with high algae density, suggest that autotrophic uptake by filamentous green algae is a major assimilatory sink of NO3 in the summer. In the natural reach, the addition of organic matter to the stream at leaf-off led to a strong decrease in N concentration (likely owing to a short-term increase in denitrification) followed by an increase in N concentration in winter as algae/plant uptake ceased. These

  19. Miscellaneous streams best management practices (BMP) report

    Energy Technology Data Exchange (ETDEWEB)

    Lueck, K.J., Westinghouse Hanford

    1996-07-24

    The Washington State Department of Ecology (Ecology) and U.S. Department of Energy Consent Order No. DE 91NM-177 (Consent Order) lists regulatory milestones for liquid effluent streams at the Hanford Site to comply with the permitting requirements of Washington Administrative Code (WAC) 173-216 (`State Waste Discharge Permit Program`) or WAC 173-218 (`Washington Underground Injection Control Program`) where applicable. Hanford Site liquid effluent streams discharging to the soil column are categorized as Phase I and Phase II Streams, and Miscellaneous Streams. There were originally 33 Phase I and Phase II Streams, however some of these streams have been eliminated. Miscellaneous Streams are those liquid effluent streams discharged to the ground that are not categorized as Phase I or Phase II Streams, and are subject to the requirements of several milestones identified in the Consent Order. The three criteria for identifying streams that are potentially affecting groundwater are: (1) streams discharging to surface contaminated areas (referred to as category `b` streams); (2) potentially contaminated streams (referred to as category `c` streams); and (3) streams discharging within 91 meters (300 feet) of a contaminated crib, ditch, or trench (referred to as category `d` streams). Miscellaneous Streams that meet any of these criteria must be evaluated for application of best management practices (BMP). The purpose of this report is to provide the best management practice preferred alternative. The list of BMP streams has been revised since the original submittal. Several streams from the original list of BMP streams have already been eliminated through facility upgrades, reduction of steam usage, and facility shutdowns. This document contains a description of the changes to the list of BMP streams, applicable definitions and regulatory requirements and possible alternatives, and a schedule for implementing the preferred alternatives.

  20. Coho salmon dependence on intermittent streams.

    Science.gov (United States)

    P.J. Wigington; J.L. Ebersole; M.E. Colvin; S.G. Leibowitz; B. Miller; B. Hansen; H. Lavigne; D. White; J.P. Baker; M.R. Church; J.R. Brooks; M.A. Cairns; J.E. Compton

    2006-01-01

    In this paper, we quantify the contributions of intermittent streams to coho salmon production in an Oregon coastal watershed. We provide estimates of (1) proportion of spawning that occurred in intermittent streams, (2) movement of juveniles into intermittent streams, (3) juvenile survival in intermittent and perennial streams during winter, and (4) relative size of...

  1. Jet stream related observations by MST radars

    Science.gov (United States)

    Gage, K. S.

    1983-01-01

    An overview of the jet stream and its observation by MST radar is presented. The climatology and synoptic and mesoscale structure of jet streams is briefly reviewed. MST radar observations of jet stream winds, and associated waves and turbulence are then considered. The possibility of using a network of ST radars to track jet stream winds in near real time is explored.

  2. Plato on the Stream. Platonism in the Age of Streaming

    Directory of Open Access Journals (Sweden)

    Frédéric Bisson

    2016-05-01

    Full Text Available This article defends a Platonist view of streaming. It is opposite to the mainstream representation that streaming has “liquidated” the structure both objective and collective of musical experience. On the contrary, streaming is the support of a new kind of musical object, which is distinct both from the allographic notational objects (scores and from the phonographic ones (records. This third kind of object has to be characterized as a flux-object. The way it is diffused and accessible implies a new kind of experience. Cyberspace in which this experience takes place is characterized as an “hyperobjective noosphere”: the relation of streaming with the subjects of musical experience is akin to the relation of atmosphere or biosphere to the living beings. This article invites to an ascetic exercise: the everyday experience of the listener has to become mindful of the “swarm community” in which s/he participates by streaming. Thus it develops a renewed musical Platonism, as a kind of response to “object-oriented ontologies”. According to this renewed Platonism, dispositional properties are essential to the objects. Objects have no sense apart from the relation to individual and collective subjectivations that are potential parts of them.

  3. Long-term patterns and short-term dynamics of stream solutes and suspended sediment in a rapidly weathering tropical watershed

    Science.gov (United States)

    Shanley, James B.; McDowell, William H.; Stallard, Robert F.

    2011-01-01

    The 326 ha Río Icacos watershed in the tropical wet forest of the Luquillo Mountains, northeastern Puerto Rico, is underlain by granodiorite bedrock with weathering rates among the highest in the world. We pooled stream chemistry and total suspended sediment (TSS) data sets from three discrete periods: 1983-1987, 1991-1997, and 2000-2008. During this period three major hurricanes crossed the site: Hugo in 1989, Hortense in 1996, and Georges in 1998. Stream chemistry reflects sea salt inputs (Na, Cl, and SO4), and high weathering rates of the granodiorite (Ca, Mg, Si, and alkalinity). During rainfall, stream composition shifts toward that of precipitation, diluting 90% or more in the largest storms, but maintains a biogeochemical watershed signal marked by elevated K and dissolved organic carbon (DOC) concentration. DOC exhibits an unusual "boomerang" pattern, initially increasing with flow but then decreasing at the highest flows as it becomes depleted and/or vigorous overland flow minimizes contact with watershed surfaces. TSS increased markedly with discharge (power function slope 1.54), reflecting the erosive power of large storms in a landslide-prone landscape. The relations of TSS and most solute concentrations with stream discharge were stable through time, suggesting minimal long-term effects from repeated hurricane disturbance. Nitrate concentration, however, increased about threefold in response to hurricanes then returned to baseline over several years following a pseudo first-order decay pattern. The combined data sets provide insight about important hydrologic pathways, a long-term perspective to assess response to hurricanes, and a framework to evaluate future climate change in tropical ecosystems.

  4. Mineralogical maps showing distribution of selected ore-related minerals in the nonmagnetic, heavy-mineral-concentrate fraction of stream sediment from the Mount Hayes 1 degree by 3 degrees Quadrangle, eastern Alaska Range, Alaska

    Science.gov (United States)

    Tripp, Richard B.; Curtin, Gary C.; Nokleberg, Warren J.; Huston, David L.; Hampton, James R.

    1993-01-01

    Exploratory geochemical sampling was done in 1979, 1980, and 1981. The collection of composite samples of stream sediment or glacial debris was emphasized the first 2 years; the last year was spent collecting mineralized stream pebbles, float, and outcrop samples. The stream-sediment and heavy- mineral-concentrate samples were collected at 795 sites on tributary streams having drainage basins ranging from 1 to 5 mi 2 in area. The glacial debris samples were collected at 116 sites on tributary glaciers also having drainage basins ranging from 1 to 5 mi2 in area. All of these samples were analyzed for 31 elements by six-step semiquantitative emission spectrography (Grimes and Marranzino, 1968). In addition, all samples were analyzed for zinc by an atomic absorption method (Ward and others, 1969). The spectrographic and chemical results are available in O'Leary and others (1982).

  5. Occurence of antibiotic compounds found in the water column and bottom sediments from a stream receiving two waste water treatment plant effluents in northern New Jersey, 2008

    Science.gov (United States)

    Gibs, Jacob; Heckathorn, Heather A.; Meyer, Michael T.; Klapinski, Frank R.; Alebus, Marzooq; Lippincott, Robert

    2013-01-01

    An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September 2008. Two of the nine sampling locations were background sites upstream from two WWTP discharges on Hohokus Brook. Another background site was located upstream from a DWI on the Saddle River above the confluence with Hohokus Brook. Because there is a weir downstream of the confluence of Hohokus Brook and Saddle River, the DWI receives water from Hohokus Brook at low stream flows. Eight antibiotic compounds (azithromycin (maximum concentration 0.24 μg/L), ciprofloxacin (0.08 μg/L), enrofloxacin (0.015 μg/L), erythromycin (0.024 μg/L), ofloxacin (0.92 μg/L), sulfamethazine (0.018 μg/L), sulfamethoxazole (0.25 μg/L), and trimethoprim (0.14 μg/L)) and a degradate (erythromycin-H2O (0.84 μg/L)) were detected in the water samples from the sites downstream from the WWTP discharges. The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin, ciprofloxacin, and

  6. Fuel-cell engine stream conditioning system

    Science.gov (United States)

    DuBose, Ronald Arthur

    2002-01-01

    A stream conditioning system for a fuel cell gas management system or fuel cell engine. The stream conditioning system manages species potential in at least one fuel cell reactant stream. A species transfer device is located in the path of at least one reactant stream of a fuel cell's inlet or outlet, which transfer device conditions that stream to improve the efficiency of the fuel cell. The species transfer device incorporates an exchange media and a sorbent. The fuel cell gas management system can include a cathode loop with the stream conditioning system transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell related to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.

  7. Arcturus stream : A case study

    Science.gov (United States)

    Ramya, P.; Reddy, Bacham Eswar

    Stellar streams are a group of gravitationally unbound stars which share same kinematic properties, and hence form coherent structures in the velocity space. Their origin is not clear. The concept of stellar streams or moving groups was introduced much early (Eggen 1958) and were thought as dispersed cluster remnants retaining the original kinematics. Subsequently, studies suggested that these are debris of accreted satellite galaxy in the Milkyway and belong to an old stellar population in the solar neighborhood. Kinematic studies reveal that the stream member stars are old and belong to thick disk of the Galaxy. Satellite acceretion scenario is one front runner proposal for the thick disk formation in the Galactic disk. In this study, we have explored one of the streams, known as Arcturus stream, through high resolution spectroscopy. Preliminary abundance results for a sample of Arcturus stream are obtained and compared with groups of stars that belong to thick disk and dwarf spheroidals. Alpha elements, that are known to be produced mainly in the massive but short lived SNII, seem to be enhanced relative to Fe, a dominant product in long lived SNIa. This suggests that the Arcturus stream stars are old and are mostly produced in the era where SNII was predominant. Abundance results are very similar to the results of Galactic thick disk, which is a distinct component in the disk, both kinematically and chemically. It seems Arcturus is a subgroup within the thick disk but to establish whether the group is distinct from the thick disk, we have to determine differential age estimate for a sample of thick disk and Arcturus stars at the overlapping [Fe/H].

  8. Numerical modelling of fine-grained sediments remobilization in heavily polluted streams. Case study: Elbe and Bílina River, Czech Republic.

    Science.gov (United States)

    Kaiglová, Jana; Langhammer, Jakub; Jiřinec, Petr; Janský, Bohumír; Chalupová, Dagmar

    2014-05-01

    The study aimed to estimate remobilization of channel and riparian cohesive sediment of streams, heavily polluted by industrial emmissions. There were analyzed four stream stretches in Czech Republic: (1) Elbe River from Usti nad Labem to the boundary with Germany; (2) Bílina river, draining industrial and mining areas of Northwest Bohemia; (3) Midstream reach of Czech Elbe by the confluence with Vltava river, affected by chemical industry and (4) fluvial lakes in the riparian zone of Czech Elbe river downstream of Pardubice burdened by old loads from heavy chemical industry. Sediments of clay and silt character bedded in the riparian water-courses are regarded heavily polluted by wide range of toxic matters. In the sediment samples, there were found elevated concentrations of persistent organic matters (DDT, PCB, HCH, Fluoranthen), Heavy metals (Hg, As, Cd), and others. The pollution in sediment is resulting from the unregulated heavy industrial production in the area in the second half of 20th century during the socialistic regime in Czech republic that still play an important role in Elbe river water quality. The main goal of the study was to evaluate the risk of remobilization of polluted sediments by the assessment of discharge (values and return periods), initiating remobilization of sediment from the river bed. The modeling stems on basic assumption, that once the sediment is elevated from the bed, it could be transported far downstream in the form of suspended load. The evaluation was made on the basis of numerical hydrodynamic calculation coupled with sediment transport model. The MIKE by DHI modelling software with different levels of schematization was used according the flow conditions and available data sources. For 50 km stretch of Bílina river the 1D schematization (MIKE 11) was selected as the discharges driving remobilization were expected within the extent of channel capacity due to the stream regulation. For the lower and middle course of Elbe

  9. Multi-scale streambed topographic and discharge effects on hyporheic at the stream network scale in confined streams

    Science.gov (United States)

    Alessandra Marzadri; Daniele Tonina; James A. McKean; Matthew G. Tiedemann; Rohan M. Benjankar

    2014-01-01

    The hyporheic zone is the volume of the streambed sediment mostly saturated with stream water. It is the transitional zone between stream and shallow-ground waters and an important ecotone for benthic species, including macro-invertebrates, microorganisms, and some fish species that dwell in the hyporheic zone for parts of their lives. Most hyporheic analyses are...

  10. Beaded streams of Arctic permafrost landscapes

    Science.gov (United States)

    Arp, C. D.; Whitman, M. S.; Jones, B. M.; Grosse, G.; Gaglioti, B. V.; Heim, K. C.

    2014-07-01

    Beaded streams are widespread in permafrost regions and are considered a common thermokarst landform. However, little is known about their distribution, how and under what conditions they form, and how their intriguing morphology translates to ecosystem functions and habitat. Here we report on a Circum-Arctic inventory of beaded streams and a watershed-scale analysis in northern Alaska using remote sensing and field studies. We mapped over 400 channel networks with beaded morphology throughout the continuous permafrost zone of northern Alaska, Canada, and Russia and found the highest abundance associated with medium- to high-ice content permafrost in moderately sloping terrain. In the Fish Creek watershed, beaded streams accounted for half of the drainage density, occurring primarily as low-order channels initiating from lakes and drained lake basins. Beaded streams predictably transition to alluvial channels with increasing drainage area and decreasing channel slope, although this transition is modified by local controls on water and sediment delivery. Comparison of one beaded channel using repeat photography between 1948 and 2013 indicate relatively stable form and 14C dating of basal sediments suggest channel formation may be as early as the Pleistocene-Holocene transition. Contemporary processes, such as deep snow accumulation in stream gulches effectively insulates river ice and allows for perennial liquid water below most beaded stream pools. Because of this, mean annual temperatures in pool beds are greater than 2 °C, leading to the development of perennial thaw bulbs or taliks underlying these thermokarst features. In the summer, some pools stratify thermally, which reduces permafrost thaw and maintains coldwater habitats. Snowmelt generated peak-flows decrease rapidly by two or more orders of magnitude to summer low flows with slow reach-scale velocity distributions ranging from 0.1 to 0.01 m s-1, yet channel runs still move water rapidly between pools

  11. Influence of large wood on channel hydraulics, sediment (dis-)connectivity and channel morphology in a medium-sized mixed-load Austrian stream

    Science.gov (United States)

    Schuchardt, Anne; Pöppl, Ronald; Morche, David

    2017-04-01

    It is widely known that large wood (LW) in rivers alters channel hydraulics, channel morphology and sediment transport. Channel spanning LW can create blocking barriers, steps and dams which store sediment and organic material in small reservoirs for the lifetime of the damming structure. Otherwise, the breach of LW key logs and jams makes the long term stored sediment available for fluvial transport. However, detailed field measurements on the distribution of LW and its influence on hydraulic variables, channel morphology and (especially) sediment connectivity are still rare, thus further constituting the major aim of this study. The study was performed along the lower reaches ( 6 km) of the Fugnitz River, a mixed-load, medium-sized (catchment area 130 km2) single-thread perennial stream, located in the Bohemian Massif, Austria. The spatial distribution and characterization of LW (>1 m in length and >10 cm in diameter) was examined along the main stem via field mapping and dGPS measurements. Hydraulic channel parameters (e.g. channel gradient, cross-sectional profiles) and volumes of retained sediment were determined via field measurements, while channel morphology incl. indications of LW-induced geomorphic processes (e.g. bank undercutting, scouring) was obtained via geomorphic mapping. Flow characteristics and bed load transport rates were measured using an Ott-Nautilus and a portable Helley-Smith bed load sampler during different water stages. Additionally, bed sediment textures were examined by performing pebble count analyses. In-channel LW accumulations (total volume of 588 m3) were primarily observed in meandering river reaches as well as in reaches with steep hillslopes. 36% of all LW accumulations were classified as dams, steps or deflectors altering flow conditions or creating backwater areas decreasing sediment connectivity. Highest volumes of sediment storage (total volume of 26 m3) have been primarily recorded at locations where bank erosion processes

  12. Fish populations in Plynlimon streams

    Directory of Open Access Journals (Sweden)

    D. T. Crisp

    1997-01-01

    Full Text Available In Plynlimon streams, brown trout (Salmo trutta L. are widespread in the upper Wye at population densities of 0.03 to 0.32 fish m-2 and show evidence of successful recruitment in most years. In the upper Severn, brown trout are found only in an area of c. 1670 -2 downstream of Blaenhafren Falls at densities of 0.03 to 0.24 fish -2 and the evidence suggests very variable year to year success in recruitment (Crisp & Beaumont, 1996. Analyses of the data show that temperature differences between afforested and unafforested streams may affect the rates of trout incubation and growth but are not likely to influence species survival. Simple analyses of stream discharge data suggest, but do not prove, that good years for recruitment in the Hafren population were years of low stream discharge. This may be linked to groundwater inputs detected in other studies in this stream. More research is needed to explain the survival of the apparently isolated trout population in the Hafren.

  13. Streaming Compression of Hexahedral Meshes

    Energy Technology Data Exchange (ETDEWEB)

    Isenburg, M; Courbet, C

    2010-02-03

    We describe a method for streaming compression of hexahedral meshes. Given an interleaved stream of vertices and hexahedral our coder incrementally compresses the mesh in the presented order. Our coder is extremely memory efficient when the input stream documents when vertices are referenced for the last time (i.e. when it contains topological finalization tags). Our coder then continuously releases and reuses data structures that no longer contribute to compressing the remainder of the stream. This means in practice that our coder has only a small fraction of the whole mesh in memory at any time. We can therefore compress very large meshes - even meshes that do not file in memory. Compared to traditional, non-streaming approaches that load the entire mesh and globally reorder it during compression, our algorithm trades a less compact compressed representation for significant gains in speed, memory, and I/O efficiency. For example, on the 456k hexahedra 'blade' mesh, our coder is twice as fast and uses 88 times less memory (only 3.1 MB) with the compressed file increasing about 3% in size. We also present the first scheme for predictive compression of properties associated with hexahedral cells.

  14. Influence of the contaminated wastes/soils on the geochemical characteristics of the Bodelhão stream waters and sediments from Panasqueira mine area, Portugal

    Science.gov (United States)

    Abreu, Maria Manuela; Godinho, Berta; Magalhães, Maria Clara F.; Anjos, Carla; Santos, Erika

    2013-04-01

    Panasqueira is a famous Portuguese tin-tungsten mine operating more or less continuously since the end of the nineteenth century. This mine is located in the Central Iberian Zone, northwest of Castelo Branco, about 35 km from Fundão, being the greatest producer of tungsten in Europe. Panasqueira mine also produces copper and tin. The ore exploitation has caused huge local visual and chemical impact from the large waste tailings, together with water drainage from mine galleries, seepage and effluents from water plant treatment. The objective of this work was to evaluate the influence of the contaminated wastes and soils on the water and sediments characteristics of the Bodelhão stream. This stream crosses the mine area at the bottom of the main tailings, receiving sediments, seepage and drainage waters from wastes and/or soils developed on the waste materials which cover the host rocks (schists), and also from the water treatment plant. Waste materials contain different levels of hazardous chemical elements depending on their age and degree of weathering (mg/kg - As: 466-632; Cd: 2.6-4.2; Cu: 264-457; Zn: 340-456; W: 40-1310). Soils developed on old wastes (60-80 years old) are mainly silty loam, acidic (except one soil (pH 8.2) developed on waste materials covered by leakage mud from a pipe conducting effluent to a pond), with relatively high concentration of organic carbon (median 48.6 g/kg). The majority of soils are heavily contaminated in As (158-7790 mg/kg), Cd (0.6-138 mg/kg), Cu (51-4081 mg/kg), W (19-1450 mg/kg), and Zn (142-12300 mg/kg). The fraction of these elements extracted with DTPA solution, relatively to total concentration, varies from low to As (10; Zn: 1.29-14.1; S: 7.2-66.9; W: 1.04-6.32, and Cd: 11.4-138 mg/kg) when compared with the same elements in soils, indicate high dispersion of the chemical elements through waters both in solution and particulate material. Bed and river banks are contaminated by sedimentation and elements adsorption

  15. Bacterial diversity and bioprospecting for cold-active enzymes from culturable bacteria associated with sediment from a melt water stream of Midtre Lovenbreen glacier, an Arctic glacier.

    Science.gov (United States)

    Vardhan Reddy, Puram Vishnu; Shiva Nageswara Rao, Singireesu Soma; Pratibha, Mambatta Shankaranarayanan; Sailaja, Buddhi; Kavya, Bakka; Manorama, Ravoori Ruth; Singh, Shiv Mohan; Radha Srinivas, Tanuku Naga; Shivaji, Sisinthy

    2009-10-01

    Culturable bacterial diversity of Midtre Lovenbreen glacier, an Arctic glacier, was studied using 12 sediment samples collected from different points, along a transect, from the snout of Midtre Lovenbreen glacier up to the convergence point of the melt water stream with the sea. Bacterial abundance appeared to be closer to the convergence point of the glacial melt water stream with the sea than at the snout of the glacier. A total of 117 bacterial strains were isolated from the sediment samples. Based on 16S rRNA gene sequence analyses, the isolates (n=117) could be categorised in to 32 groups, with each group representing a different taxa belonging to 4 phyla (Actinobacteria, Bacilli, Flavobacteria and Proteobacteria). Representatives of the 32 groups varied in their growth temperature range (4-37 degrees C), in their tolerance to NaCl (0.1-1M NaCl) and in the growth pH range (2-13). Only 14 of 32 representative strains exhibited amylase, lipase and (or) protease activity and only one isolate (AsdM4-6) showed all three enzyme activities at 5 and 20 degrees C respectively. More than half of the isolates were pigmented. Fatty acid profile studies indicated that short-chain fatty acids, unsaturated fatty acids, branched fatty acids, cyclic and cis fatty acids are predominant in the psychrophilic bacteria.

  16. Density/area power-law models for separating multi-scale anomalies of ore and toxic elements in stream sediments in Gejiu mineral district, Yunnan Province, China

    Science.gov (United States)

    Cheng, Q.; Xia, Q.; Li, W.; Zhang, S.; Chen, Z.; Zuo, R.; Wang, W.

    2010-10-01

    This contribution introduces a fractal filtering technique newly developed on the basis of a spectral energy density vs. area power-law model in the context of multifractal theory. It can be used to map anisotropic singularities of geochemical landscapes created from geochemical concentration values in various surface media such as soils, stream sediments, tills and water. A geochemical landscape can be converted into a Fourier domain in which the spectral energy density is plotted against the area (in wave number units), and the relationship between the spectrum energy density (S) and the area (A) enclosed by the above-threshold spectrum energy density can be fitted by power-law models. Mixed geochemical landscape patterns can be fitted with different S-A power-law models in the frequency domain. Fractal filters can be defined according to these different S-A models and used to decompose the geochemical patterns into components with different self-similarities. The fractal filtering method was applied to a geochemical dataset from 7,349 stream sediment samples collected from Gejiu mineral district, which is famous for its word-class tin and copper production. Anomalies in three different scales were decomposed from total values of the trace elements As, Sn, Cu, Zn, Pb, and Cd. These anomalies generally correspond to various geological features and geological processes such as sedimentary rocks, intrusions, fault intersections and mineralization.

  17. Density/area power-law models for separating multi-scale anomalies of ore and toxic elements in stream sediments in Gejiu mineral district, Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    Q. Cheng

    2010-10-01

    Full Text Available This contribution introduces a fractal filtering technique newly developed on the basis of a spectral energy density vs. area power-law model in the context of multifractal theory. It can be used to map anisotropic singularities of geochemical landscapes created from geochemical concentration values in various surface media such as soils, stream sediments, tills and water. A geochemical landscape can be converted into a Fourier domain in which the spectral energy density is plotted against the area (in wave number units, and the relationship between the spectrum energy density (S and the area (A enclosed by the above-threshold spectrum energy density can be fitted by power-law models. Mixed geochemical landscape patterns can be fitted with different S-A power-law models in the frequency domain. Fractal filters can be defined according to these different S-A models and used to decompose the geochemical patterns into components with different self-similarities. The fractal filtering method was applied to a geochemical dataset from 7,349 stream sediment samples collected from Gejiu mineral district, which is famous for its word-class tin and copper production. Anomalies in three different scales were decomposed from total values of the trace elements As, Sn, Cu, Zn, Pb, and Cd. These anomalies generally correspond to various geological features and geological processes such as sedimentary rocks, intrusions, fault intersections and mineralization.

  18. National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment reconnaissance basic data for Beeville NTMS Quadrangle, Texas. Uranium resource evaluation project

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-31

    Results of a reconnaissance geochemical survey of the Beeville Quadrangle, Texas are reported. Field and laboratory data are presented for 373 groundwater and 364 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. The groundwater data indicate that the northwestern corner of the quadrangle is the most favorable for potential uranium mineralization. Favorability is indicated by high uranium concentrations; high arsenic, molybdenum, and vanadium concentrations; and proximity and similar geologic setting to the mines of the Karnes County mining district. Other areas that appear favorable are an area in Bee and Refugio Counties and the northeastern part of the quadrangle. Both areas have water chemistry similar to the Karnes County area, but the northeastern area does not have high concentrations of pathfinder elements. The stream sediment data indicate that the northeastern corner of the quadrangle is the most favorable for potential mineralization, but agricultural practices and mineralogy of the outcropping Beaumont Formation may indicate a false anomaly. The northwestern corner of the quadrangle is considered favorable because of its proximity to the known uranium deposits, but the data do not seem to support this.

  19. Algal-bacterial co-variation in streams: a cross-stream comparison

    Science.gov (United States)

    Xueqing Gao; Ola A. Olapade; Mark W. Kershner; Laura G. Leff

    2004-01-01

    Algal-bacterial co-variation has been frequently observed in lentic and marine environments, but the existence of such relationships in lotic ecosystems is not well established. To examine possible co-variation, bacterial number and chlorophyll-a concentration in water and sediments of nine streams from different regions in the USA were examined. In the water, a strong...

  20. Stream Channel Stability.

    Science.gov (United States)

    1981-04-01

    bend causes the water surface to be higher at the outside bank. This transverse slope causes a helicoidal flow in the bend that sweeps the bed material...return flow , evapotranspiration, water balance in reservoirs, sediment yield and input data requirements are discussed. The quasi 3-dijmensional... water surface and bed profiles of flow across a trench ....................... .195 43 Computed sediment concentrations of flow across a trench

  1. Site investigation SFR. Vegetation in streams in the Forsmark area

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Eva (Svensk Nuclear Fuel and Waste Management Co. (Sweden)); Aquilonius, Karin; Sivars Becker, Lena (Studsvik Nuclear AB (Sweden)); Borgiel, Mikael (Sveriges Vattenekologer AB (Sweden))

    2011-09-15

    The streams in the model area of Forsmark have previously been thoroughly investigated regarding water chemistry, hydrology, bottom substrate, flooding, percentage coverage of macrophytes and fish migration. Retention of radionuclides in a stream ecosystem is assumed to occur by sorption to sediments or by uptake of radionuclides by macrophytes and it is therefore of interest to know the biomass and production of macrophytes in the streams included in a safety assessment. The general aim of this study was to examine the relation between biomass and the percentage cover of vegetation in streams in the Forsmark area. In this study streams within and nearby the candidate area in Forsmark was investigated. The somewhat larger streams Forsmarksaan and Olandsaan nearby the candidate area, are assumed to be more similar to future streams developing in Forsmark due to landrise, than the smaller streams present in the candidate area today. In total 22 vegetation samples were gathered in order to estimate the biomass at the sites. Percentage coverage of macrophytes, and dominating species were noted and the above ground macrophytes were sampled for biomass analysis. In the smaller streams, the biomass varied between 6 and almost 358 g dry weight per square metre. In the larger streams, the dry biomass varied between 0 and 247 g dry weight per square meter. There were no significant difference between macrophyte biomass in smaller and the larger stream. In total 13 macrophyte species were found. The biomass dry weight at 100% covering degree varied depending on macrophyte species. Although this was a rather small study, it is evident that the biomasses do vary a wide range between sampling squares in the area. However, although it may be difficult to use this data set to estimate the biomass in a specific square meter in the stream section, the relation between biomass weight and covering degree is sufficient to be used when fitting biomass to macrophyte coverage for entire

  2. Continuous sampling from distributed streams

    DEFF Research Database (Denmark)

    Graham, Cormode; Muthukrishnan, S.; Yi, Ke

    2012-01-01

    A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple...... distributed sites. The main challenge is to ensure that a sample is drawn uniformly across the union of the data while minimizing the communication needed to run the protocol on the evolving data. At the same time, it is also necessary to make the protocol lightweight, by keeping the space and time costs low...... for each participant. In this article, we present communication-efficient protocols for continuously maintaining a sample (both with and without replacement) from k distributed streams. These apply to the case when we want a sample from the full streams, and to the sliding window cases of only the W most...

  3. ATLAS Live: Collaborative Information Streams

    CERN Document Server

    Goldfarb, S; The ATLAS collaboration

    2010-01-01

    I report on a pilot project launched in 2010 focusing on facilitating communication and information exchange within the ATLAS Collaboration, through the combination of digital signage software and webcasting. The project, called ATLAS Live, implements video streams of information, ranging from detailed detector and data status to educational and outreach material. The content, including text, images, video and audio, is collected, visualised and scheduled using the SCALA digital signage software system. The system is robust and flexible, allowing for the usage of scripts to input data from remote sources, such as the CERN Document Server, Indico, or any available URL, and to integrate these sources into professional-quality streams, including text scrolling, transition effects, inter and intrascreen divisibility. The video is made available to the collaboration or public through the encoding and webcasting of standard video streams, viewable on all common platforms, using a web browser or other common video t...

  4. A Robust Streaming Media System

    Science.gov (United States)

    Youwei, Zhang

    Presently, application layer multicast protocols (ALM) are proposed as substitute for IP multicast and have made extraordinary achievements. Integrated with Multi-data-stream mode such as Multiple Description Coding (MDC), ALM becomes more scalable and robust in high-dynamic Internet environment compared with single data stream. Although MDC can provide a flexible data transmission style, the synchronization of different descriptions encoded from one video source is proved to be difficult due to different delay on diverse transmission paths. In this paper, an ALM system called HMDC is proposed to improve accepted video quality of streaming media, hosts can join the separate overlay trees in different layers simultaneously, then the maximum synchronized descriptions of the same layer are worked out to acquire the best video quality. Simulations implemented on Internet-like topology indicate that HMDC achieves better video quality, lower link stress, higher robustness and comparable latency compared with traditional ALM protocols.

  5. Water-quality, bed-sediment, and biological data (October 2014 through September 2015) and statistical summaries of data for streams in the Clark Fork Basin, Montana

    Science.gov (United States)

    Dodge, Kent A.; Hornberger, Michelle I.; Turner, Matthew A.

    2017-01-19

    Water, bed sediment, and biota were sampled in selected streams from Butte to near Missoula, Montana, as part of a monitoring program in the upper Clark Fork Basin of western Montana. The sampling program was led by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to characterize aquatic resources in the Clark Fork Basin, with emphasis on trace elements associated with historic mining and smelting activities. Sampling sites were located on the Clark Fork and selected tributaries. Water samples were collected periodically at 20 sites from October 2014 through September 2015. Bed-sediment and biota samples were collected once at 13 sites during August 2015.This report presents the analytical results and quality-assurance data for water-quality, bed-sediment, and biota samples collected at sites from October 2014 through September 2015. Water-quality data include concentrations of selected major ions, trace elements, and suspended sediment. At 12 sites, samples for analysis of dissolved organic carbon and turbidity were collected. In addition, samples for analysis of nitrogen (nitrate plus nitrite) were collected at two sites. Daily values of mean suspended-sediment concentration and suspended-sediment discharge were determined for three sites. Seasonal daily values of turbidity were determined for four sites. Bed-sediment data include trace-element concentrations in the fine-grained fraction. Biological data include trace-element concentrations in whole-body tissue of aquatic benthic insects. Statistical summaries of water-quality, bed-sediment, and biological data for sites in the upper Clark Fork Basin are provided for the period of record.

  6. Comparison of active and passive stream restoration

    DEFF Research Database (Denmark)

    Kristensen, Esben Astrup; Thodsen, Hans; Dehli, Bjarke

    2013-01-01

    -stream habitats were compared through analysis of the measured physical parameters and by applying a habitat model. We found that re-meandering is a more effective way of re-creating near-natural physical conditions in small streams compared to passive restoration. This is probably due to the limited energy...... methods are plentiful, it is difficult to determine which one to use to get the anticipated result. The aim of this study was to compare two commonly used methods in small Danish streams to improve the physical condition: re-meandering and passive restoration through cease of maintenance. Our...... investigation included measurement of the physical conditions in 29 stream reaches covering four different groups: (1) re-meandered streams, (2) LDC streams (the least disturbed streams available), (3) passively restored streams (>10 years stop of aintenance) and (4) channelized and non-restored streams. The in...

  7. DOWN-STREAM SPATIAL DISTRIBUTION OF ANTIBIOTIC RESISTANCE TRAITS ALONG METAL CONTAMINATED STREAM REACHES

    Energy Technology Data Exchange (ETDEWEB)

    Tuckfield, C; J V Mcarthur (NOEMAIL), J

    2007-04-16

    Sediment bacteria samples were collected from three streams in South Carolina, two contaminated with multiple metals (Four Mile Creek and Castor Creek), one uncontaminated (Meyers Branch), and another metal contaminated stream (Lampert Creek) in northern Washington State. Growth plates inoculated with Four Mile Creek sample extracts show bacteria colony growth after incubation on plates containing either one of two aminoglycosides (kanamycin or streptomycin), tetracycline or chloramphenocol. This study analyzes the spatial pattern of antibiotic resistance in culturable sediment bacteria in all four streams that may be due to metal contamination. We summarize the two aminoglycoside resistance measures and the 10 metals concentrations by Principal Components Analysis. Respectively, 63% and 58% of the variability was explained in the 1st principal component of each variable set. We used the respective multivariate summary metrics (i.e. 1st principal component scores) as input measures for exploring the spatial correlation between antibiotic resistance and metal concentration for each stream reach sampled. Results show a significant and negative correlation between metals scores versus aminoglycoside resistance scores and suggest that selection for metal tolerance among sediment bacteria may influence selection for antibiotic resistance differently than previously supposed.. In addition, we borrow a method from geostatistics (variography) wherein a spatial cross-correlation analysis shows that decreasing metal concentrations scores are associated with increasing aminoglycoside resistance scores as the separation distance between sediment samples decreases, but for contaminated streams only. Since these results were counter to our initial expectation and to other experimental evidence for water column bacteria, we suspect our field results are influenced by metal bioavailability in the sediments and by a contaminant promoted interaction or ''cocktail effect

  8. Stream-processing pipelines: processing of streams on multiprocessor architecture

    NARCIS (Netherlands)

    Kavaldjiev, N.K.; Smit, Gerardus Johannes Maria; Jansen, P.G.

    In this paper we study the timing aspects of the operation of stream-processing applications that run on a multiprocessor architecture. Dependencies are derived for the processing and communication times of the processors in such a system. Three cases of real-time constrained operation and four

  9. Macroinvertebrate community structure and function along gradients of physical stream quality and pesticide contamination in Danish streams

    DEFF Research Database (Denmark)

    Rasmussen, Jes

    to stream are surface runoff and tile drainage giving rise to short pulses of acute contamination strongly coinciding with high levels of precipitation. Field studies indicate that macroinvertebrate community structure can be impacted by pesticides during spraying seasons in May and June, but also......  A wide array of pesticides are applied to agricultural crops during spring and autumn spraying season, and detections of pesticides in stream water and bed sediments of agricultural streams emphasize the potential exposure of benthic macroinvertebrates. Major transportation routes from catchment...... in each stream were measured applying sediment sampling and event triggered water samplers. Furthermore, on all reaches macroinvertebrate community structure was assessed before, during and after the spring application season. Stream reaches with good physical quality generally contain a higher abundance...

  10. Investigating methods of stream planform identification

    Science.gov (United States)

    Lohberg, M. M.; Lusk, K.; Miller, D.; Stonedahl, F.; Stonedahl, S. H.

    2013-12-01

    require even smaller increments, drastically increasing field work time. These two non-photo methods also disturb the sediments in the stream, which may be undesirable. Finally, the 'square method' provided a high resolution outline with only a 1.51% error and was relatively easy to complete in the field. It did, however, require a great-deal of manual post-processing time. Despite this caveat, we recommend the square method as an inexpensive procedure for obtaining fine resolution planform data with minimal disturbance to the stream environment. Stream planforms and calculated control point locations with respective average percent errors

  11. On the dynamics of stream piracy

    Science.gov (United States)

    Goren, L.; Willett, S. D.

    2012-04-01

    Drainage network reorganization by stream piracy is invoked repeatedly to explain the morphology of unique drainage patterns and as a possible mechanism inducing abrupt variations of sediment accumulation rates. However, direct evidence of stream piracy is usually rare, and is highly interpretation dependent. As a first step in assessing how probable capture events are and establishing the conditions that favor stream piracy versus the those that favor stable landscapes, we formulate analytically the physics of divide migration and capture events and study this formulation from a dynamical system point of view. The formulation is based on a one-dimensional topographic cross section between two channels that share a water divide. Two hillslope profiles diverge from the divide and drain into two fluvial bedrock tributaries, whose erosion rate is controlled by a stream power law. The rate of erosion at the bounding channels is thus a function of the upstream drainage area and local slope. A tectonically induced downward perturbation of the elevation of one of the bounding channels lowers the channel slope but at the same time increases the drainage area due to outward migration of the water divide. The changes in slope and area have opposing effect on the erosion rate at the bounding channels, so that the perturbation may either grow or be damped. We define the geomorphic and tectonic parameters that control the behavior of the system and find the regimes that lead to stable landscapes and to capture events.

  12. MICROTURBULENCE IN GRAVEL BED STREAMS

    Science.gov (United States)

    Papanicolaou, T.; Tsakiris, A. G.; Kramer, C. M.

    2009-12-01

    The overarching objective of this investigation was to evaluate the role of relative submergence on the formation and evolution of cluster microforms in gravel bed streams and its implications to bedload transport. Secondary objectives of this research included (1) a detailed analysis of mean flow measurements around a clast; and (2) a selected number of experimental runs where the mean flow characteristics are linked together with the bed micro-topography observations around a clast. It is hypothesized that the relative submergence is an important parameter in defining the feedback processes between the flow and clasts, which governs the flow patterns around the clasts, thus directly affecting the depositional patterns of the incoming sediments. To examine the validity of the hypothesis and meet the objectives of this research, 19 detailed experimental runs were conducted in a tilting, water recirculating laboratory flume under well-controlled conditions. A fixed array of clast-obstacles were placed atop a well-packed bed with uniform size glass beads. During the runs, multifractional spherical particles were fed upstream of the clast section at a predetermined rate. State-of-the-art techniques/instruments, such as imaging analysis software, Large Scale Particle Velocimeter (LSPIV) and an Acoustic Doppler Velocimetry (ADV) were employed to provide unique quantitative measurements for bedload fluxes, clast/clusters geomorphic patterns, and mean flow characteristics in the vicinity of the clusters. Different flow patterns were recorded for the high relative submergence (HRS) and low relative submergence (LRS) experimental runs. The ADV measurements provided improved insight about the governing flow mechanisms for the HRS runs. These mechanisms were described with flow upwelling at the center of the flume and downwelling occurring along the flume walls. Flow downwelling corresponded to an increase in the free surface velocity. Additionally, the visual observations

  13. Stretch-minimising stream surfaces

    KAUST Repository

    Barton, Michael

    2015-05-01

    We study the problem of finding stretch-minimising stream surfaces in a divergence-free vector field. These surfaces are generated by motions of seed curves that propagate through the field in a stretch minimising manner, i.e., they move without stretching or shrinking, preserving the length of their arbitrary arc. In general fields, such curves may not exist. How-ever, the divergence-free constraint gives rise to these \\'stretch-free\\' curves that are locally arc-length preserving when infinitesimally propagated. Several families of stretch-free curves are identified and used as initial guesses for stream surface generation. These surfaces are subsequently globally optimised to obtain the best stretch-minimising stream surfaces in a given divergence-free vector field. Our algorithm was tested on benchmark datasets, proving its applicability to incompressible fluid flow simulations, where our stretch-minimising stream surfaces realistically reflect the flow of a flexible univariate object. © 2015 Elsevier Inc. All rights reserved.

  14. ALIENS IN WESTERN STREAM ECOSYSTEMS

    Science.gov (United States)

    The USEPA's Environmental Monitoring and Assessment Program conducted a five year probability sample of permanent mapped streams in 12 western US states. The study design enables us to determine the extent of selected riparian invasive plants, alien aquatic vertebrates, and some ...

  15. Analysis of streaming media systems

    NARCIS (Netherlands)

    Lu, Y.

    2010-01-01

    Multimedia services have been popping up at tremendous speed in recent years. A large number of these multimedia streaming systems are introduced to the consumer market. Internet Service Providers, Telecommunications Operators, Service/Content Providers, and end users are interested in the

  16. Efficient architectures for streaming applications

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Kokkeler, Andre B.J.; Wolkotte, P.T.; van de Burgwal, M.D.; Heysters, P.M.; Athanas, P.; Becker, J.; Brebner, G.; Teich, J.

    2006-01-01

    This presentation will focus on algorithms and reconfigurable tiled architectures for streaming DSP applications. The tile concept will not only be applied on chip level but also on board-level and system-level. The tile concept has a number of advantages: (1) depending on the requirements more or

  17. Video Streaming in Online Learning

    Science.gov (United States)

    Hartsell, Taralynn; Yuen, Steve Chi-Yin

    2006-01-01

    The use of video in teaching and learning is a common practice in education today. As learning online becomes more of a common practice in education, streaming video and audio will play a bigger role in delivering course materials to online learners. This form of technology brings courses alive by allowing online learners to use their visual and…

  18. Estimated Perennial Streams in Idaho

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Perennial streams in Idaho have been modeled using regression equations for 7-day, 2-year low flows (7Q2) described in Wood and others (2009, U.S. Geological Survey...

  19. INFORMATION STREAMS OF LOGISTICAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    E. N. Zhivitskaya

    2013-01-01

    Full Text Available The problem of formalisation and practical realisation of information streams of logistical systems, as the basic component of a separate kind of systems the logistical information systems having the features and properties that allows to investigate them by means of methods, applicable to information systems is considered.

  20. Data streams models and algorithms

    CERN Document Server

    2007-01-01

    Discusses issues related to the mining aspects of data streams. Each chapter in this book contains a survey on the topic, the key ideas in the field for that particular topic, and future research directions. It is intended for a professional audience composed of researchers and practitioners in industry.

  1. Cryptanalysis of chaotic stream cipher

    Energy Technology Data Exchange (ETDEWEB)

    Skrobek, Adrian [Szczecin University of Technology, 71-210 Szczecin (Poland)]. E-mail: askrobek@wi.ps.pl

    2007-03-19

    In [N.S. Philip, K.B. Joseph, Chaos for stream cipher, cs.CR/0102012] Philip and Joseph propose their own cipher algorithm. An efficient attack on the values of the key of this cipher is presented in this Letter. Other weaknesses of this cipher are presented, and proposals of algorithm's improvement as well.

  2. Spatial Stream Segregation by Cats.

    Science.gov (United States)

    Javier, Lauren K; McGuire, Elizabeth A; Middlebrooks, John C

    2016-06-01

    Listeners can perceive interleaved sequences of sounds from two or more sources as segregated streams. In humans, physical separation of sound sources is a major factor enabling such stream segregation. Here, we examine spatial stream segregation with a psychophysical measure in domestic cats. Cats depressed a pedal to initiate a target sequence of brief sound bursts in a particular rhythm and then released the pedal when the rhythm changed. The target bursts were interleaved with a competing sequence of bursts that could differ in source location but otherwise were identical to the target bursts. This task was possible only when the sources were heard as segregated streams. When the sound bursts had broad spectra, cats could detect the rhythm change when target and competing sources were separated by as little as 9.4°. Essentially equal levels of performance were observed when frequencies were restricted to a high, 4-to-25-kHz, band in which the principal spatial cues presumably were related to sound levels. When the stimulus band was restricted from 0.4 to 1.6 kHz, leaving interaural time differences as the principal spatial cue, performance was severely degraded. The frequency sensitivity of cats in this task contrasts with that of humans, who show better spatial stream segregation with low- than with high-frequency sounds. Possible explanations for the species difference includes the smaller interaural delays available to cats due to smaller sizes of their heads and the potentially greater sound-level cues available due to the cat's frontally directed pinnae and higher audible frequency range.

  3. Streaming Visual Analytics Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Kristin A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burtner, Edwin R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kritzstein, Brian P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brisbois, Brooke R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mitson, Anna E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-31

    How can we best enable users to understand complex emerging events and make appropriate assessments from streaming data? This was the central question addressed at a three-day workshop on streaming visual analytics. This workshop was organized by Pacific Northwest National Laboratory for a government sponsor. It brought together forty researchers and subject matter experts from government, industry, and academia. This report summarizes the outcomes from that workshop. It describes elements of the vision for a streaming visual analytic environment and set of important research directions needed to achieve this vision. Streaming data analysis is in many ways the analysis and understanding of change. However, current visual analytics systems usually focus on static data collections, meaning that dynamically changing conditions are not appropriately addressed. The envisioned mixed-initiative streaming visual analytics environment creates a collaboration between the analyst and the system to support the analysis process. It raises the level of discourse from low-level data records to higher-level concepts. The system supports the analyst’s rapid orientation and reorientation as situations change. It provides an environment to support the analyst’s critical thinking. It infers tasks and interests based on the analyst’s interactions. The system works as both an assistant and a devil’s advocate, finding relevant data and alerts as well as considering alternative hypotheses. Finally, the system supports sharing of findings with others. Making such an environment a reality requires research in several areas. The workshop discussions focused on four broad areas: support for critical thinking, visual representation of change, mixed-initiative analysis, and the use of narratives for analysis and communication.

  4. Stream Tables and Watershed Geomorphology Education.

    Science.gov (United States)

    Lillquist, Karl D.; Kinner, Patricia W.

    2002-01-01

    Reviews copious stream tables and provides a watershed approach to stream table exercises. Results suggest that this approach to learning the concepts of fluvial geomorphology is effective. (Contains 39 references.) (DDR)

  5. Cytoplasmic Streaming in the Drosophila Oocyte.

    Science.gov (United States)

    Quinlan, Margot E

    2016-10-06

    Objects are commonly moved within the cell by either passive diffusion or active directed transport. A third possibility is advection, in which objects within the cytoplasm are moved with the flow of the cytoplasm. Bulk movement of the cytoplasm, or streaming, as required for advection, is more common in large cells than in small cells. For example, streaming is observed in elongated plant cells and the oocytes of several species. In the Drosophila oocyte, two stages of streaming are observed: relatively slow streaming during mid-oogenesis and streaming that is approximately ten times faster during late oogenesis. These flows are implicated in two processes: polarity establishment and mixing. In this review, I discuss the underlying mechanism of streaming, how slow and fast streaming are differentiated, and what we know about the physiological roles of the two types of streaming.

  6. A recirculating stream aquarium for ecological studies.

    Science.gov (United States)

    Gordon H. Reeves; Fred H. Everest; Carl E. McLemore

    1983-01-01

    Investigations of the ecological behavior of fishes often require studies in both natural and artificial stream environments. We describe a large, recirculating stream aquarium and its controls, constructed for ecological studies at the Forestry Sciences Laboratory in Corvallis.

  7. Dispersal of plant fragments in small streams

    DEFF Research Database (Denmark)

    Riis, T.; Sand-Jensen, K.

    2006-01-01

    ) in the exponential equation a suitable measure for comparisons among different macrophyte species, and between stream reaches of different hydrology and vegetation cover. 3. Buoyancy of macrophyte tissue influenced retention. Elodea canadensis stems drifted below the water surface, and were more inclined......1. Streams are subject to frequent natural and anthropogenic disturbances that cause sediment erosion and loss of submerged vegetation. This loss makes downstream transport and retention of vegetative propagules on the streambed very important for re-establishing vegetation cover. We measured...... to be retained in deeper water associated with submerged plants and obstacles in the streambed. Ranunculus peltatus stems were more buoyant, drifted at the water surface, and were more inclined to be trapped in shallow water and in riparian vegetation. 4. The retention coefficient of drifting stems increased...

  8. Whole-stream response to nitrate loading in three streams draining agricultural landscapes.

    Science.gov (United States)

    Duff, John H; Tesoriero, Anthony J; Richardson, William B; Strauss, Eric A; Munn, Mark D

    2008-01-01

    Physical, chemical, hydrologic, and biologic factors affecting nitrate (NO3(-)) removal were evaluated in three agricultural streams draining orchard/dairy and row crop settings. Using 3-d "snapshots" during biotically active periods, we estimated reach-level NO3(-) sources, NO3(-) mass balance, in-stream processing (nitrification, denitrification, and NO3(-) uptake), and NO3(-) retention potential associated with surface water transport and ground water discharge. Ground water contributed 5 to 11% to stream discharge along the study reaches and 8 to 42% of gross NO3(-) input. Streambed processes potentially reduced 45 to 75% of ground water NO3(-) before discharge to surface water. In all streams, transient storage was of little importance for surface water NO3(-) retention. Estimated nitrification (1.6-4.4 mg N m(-2) h(-1)) and unamended denitrification rates (2.0-16.3 mg N m(-2) h(-1)) in sediment slurries were high relative to pristine streams. Denitrification of NO3(-) was largely independent of nitrification because both stream and ground water were sources of NO3(-). Unamended denitrification rates extrapolated to the reach-scale accounted for Nitrate retention as a percentage of gross NO3(-) inputs was >30% in an organic-poor, autotrophic stream with the lowest denitrification potentials and highest benthic chlorophyll a, photosynthesis/respiration ratio, pH, dissolved oxygen, and diurnal NO3(-) variation. Biotic processing potentially removed 75% of ground water NO3(-) at this site, suggesting an important role for photosynthetic assimilation of ground water NO3(-) relative to subsurface denitrification as water passed directly through benthic diatom beds.

  9. Nutrient processes at the stream-lake interface for a channelized versus unmodified stream mouth

    Science.gov (United States)

    Niswonger, Richard G.; Naranjo, Ramon C.; Smith, David; Constantz, James E.; Allander, Kip K.; Rosenberry, Donald O.; Neilson, Bethany; Rosen, Michael R.; Stonestrom, David A.

    2017-01-01

    Inorganic forms of nitrogen and phosphorous impact freshwater lakes by stimulating primary production and affecting water quality and ecosystem health. Communities around the world are motivated to sustain and restore freshwater resources and are interested in processes controlling nutrient inputs. We studied the environment where streams flow into lakes, referred to as the stream-lake interface (SLI), for a channelized and unmodified stream outlet. Channelization is done to protect infrastructure or recreational beach areas. We collected hydraulic and nutrient data for surface water and shallow groundwater in two SLIs to develop conceptual models that describe characteristics that are representative of these hydrologic features. Water, heat, and solute transport models were used to evaluate hydrologic conceptualizations and estimate mean residence times of water in the sediment. A nutrient mass balance model is developed to estimate net rates of adsorption and desorption, mineralization, and nitrification along subsurface flow paths. Results indicate that SLIs are dynamic sources of nutrients to lakes and that the common practice of channelizing the stream at the SLI decreases nutrient concentrations in pore water discharging along the lakeshore. This is in contrast to the unmodified SLI that forms a barrier beach that disconnects the stream from the lake and results in higher nutrient concentrations in pore water discharging to the lake. These results are significant because nutrient delivery through pore water seepage at the lakebed from the natural SLI contributes to nearshore algal communities and produces elevated concentrations of inorganic nutrients in the benthic zone where attached algae grow.

  10. Modeling Stream Bank Erosion: Practical Stream Results and Future Needs

    Directory of Open Access Journals (Sweden)

    Yong G. Lai

    2017-12-01

    Full Text Available Coupled two-dimensional (2D morphodynamic and bank erosion models are gaining attentions in recent years. It has been shown that such models have advantages over the one-dimensional (1D modeling approaches. In this paper, a previous 2D bank erosion model with the moving mesh method is extended to include the fixed mesh approach. Further, two practical streams with differing complexity are simulated to demonstrate the extended model. Both the moving mesh and fixed mesh methods are used in the modeling. The model consists of two components: a 2D flow and mobile-bed model for vertical bed changes and hydraulic forces acting on a bank and a lateral bank retreat model. The 2D vertical model and the lateral bank erosion model are coupled together spatially and temporally through a special procedure and a common mesh. With the experiences gained with practical stream modeling, the modeling procedure and key model input parameters are described. The study shows that the moving and fixed mesh methods together make the extended bank erosion model numerically robust and capable of predicting both the vertical bed changes and the lateral stream bank erosion for complex streams. Each individual method, however, has its own limitations in terms of model accuracy and efficiency. The moving mesh works well if bank retreat is relatively small, e.g., less than one channel width, and produces more accurate results than the fixed mesh method. The fixed mesh may be needed for ensuring numerical stability if a bank may be subject to significant retreat (e.g., more than one channel width. The fixed mesh method, however, is less accurate than the moving mesh method and a much refined mesh may be needed. Both methods need future research and improvements in terms of their model accuracy.

  11. Scranton 1/sup 0/ x 2/sup 0/ NTMS area: New Jersey, New York, and Pennsylvania. Preliminary basic data report. National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment reconnaissance

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, R.B.; Tones, P.L.

    1978-11-01

    Stream sediment and stream water samples were collected from small streams at 980 sites for a nominal density of one site per 18 square kilometers in rural areas. Ground water samples were collected at 1251 sites for a nominal density of one site per 13 square kilometers. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water and surface water. Field measurements and observations are reported for each site. Analytical data and field measurements 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.

  12. Stream Gauges and Satellite Measurements

    Science.gov (United States)

    Alsdorf, D. E.

    2010-12-01

    Satellite measurements should not be viewed as a replacement for stream gauges. However, occasionally it is suggested that because satellite-based measurements can provide river discharge, a motivation for satellite approaches is an increasing lack of stream gauges. This is an argument for more stream gauges, but not necessarily for satellite measurements. Rather, in-situ and spaceborne methods of estimating discharge are complementary. Stream gauges provide frequent measurements at one point in the river reach whereas satellites have the potential to measure throughout all reaches but at orbital repeat intervals of days to weeks. The Surface Water and Ocean Topography satellite mission (SWOT) is an opportunity to further develop these complements. The motivation for SWOT, and indeed for any satellite based method of estimating discharge, should not be as a replacement for stream gauges. Scientific and application uses should motivate the measurements. For example, understanding floods with their dynamic water surfaces are best sampled from remote platforms that provide water surface elevations throughout the floodwave. As another example, today’s water and energy balance models are giving outputs at increasing spatial resolution and are making use of water surface elevations throughout the modeled basin. These models require a similar resolution in the calibrating and validating observations. We should also be aware of practical limitations. In addition to providing spatially distributed hydrodynamic measurements on rivers, SWOT will be able to measure storage changes in the estimated 30 million lakes in the world that are larger than a hectare. Knowing the storage changes in these lakes is especially important in certain regions such as the Arctic but gauging even a small fraction of these is impractical. Another motivator for satellite methods is that even in the presence of stream gauges, discharge data is not always well shared throughout all countries

  13. Energy from streaming current and potential

    NARCIS (Netherlands)

    Olthuis, Wouter; Schippers, Bob; Eijkel, Jan C.T.; van den Berg, Albert

    2005-01-01

    It is investigated how much energy can be delivered by a streaming current source. A streaming current and subsequent streaming potential originate when double layer charge is transported by hydrodynamic flow. Theory and a network model of such a source is presented and initial experimental results

  14. Maximizing Resource Utilization in Video Streaming Systems

    Science.gov (United States)

    Alsmirat, Mohammad Abdullah

    2013-01-01

    Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…

  15. Stream dynamics: An overview for land managers

    Science.gov (United States)

    Burchard H. Heede

    1980-01-01

    Concepts of stream dynamics are demonstrated through discussion of processes and process indicators; theory is included only where helpful to explain concepts. Present knowledge allows only qualitative prediction of stream behavior. However, such predictions show how management actions will affect the stream and its environment.

  16. Reconfigurable Multicore Architectures for Streaming Applications

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Kokkeler, Andre B.J.; Rauwerda, G.K.; Jacobs, J.W.M.; Nicolescu, G.; Mosterman, P.J.

    2009-01-01

    This chapter addresses reconfigurable heterogenous and homogeneous multicore system-on-chip (SoC) platforms for streaming digital signal processing applications, also called DSP applications. In streaming DSP applications, computations can be specified as a data flow graph with streams of data items

  17. Trace elements in Zn Pb Ag deposits and related stream sediments, Brooks Range Alaska, with implications for Tl as a pathfinder element

    Science.gov (United States)

    Graham, G.E.; Kelley, K.D.; Slack, J.F.; Koenig, A.E.

    2009-01-01

    The Zn-Pb-Ag metallogenic province of the western and central Brooks Range, Alaska, contains two distinct but mineralogically similar deposit types: shale-hosted massive sulphide (SHMS) and smaller vein-breccia occurrences. Recent investigations of the Red Dog and Anarraaq SHMS deposits demonstrated that these deposits are characterized by high trace-element concentrations of As, Ge, Sb and Tl. This paper examines geochemistry of additional SHMS deposits (Drenchwater and Su-Lik) to determine which trace elements are ubiquitously elevated in all SHMS deposits. Data from several vein-breccia occurrences are also presented to see if trace-element concentrations can distinguish SHMS deposits from vein-breccia occurrences. Whole-rock geochemical data indicate that Tl is the most consistently and highly concentrated characteristic trace element in SHMS deposits relative to regional unmineralized rock samples. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of pyrite and sphalerite indicate that Tl is concentrated in pyrite in SHMS. Stream sediment data from the Drenchwater and Su-Lik SHMS show that high Tl concentrations are more broadly distributed proximal to known or suspected mineralization than As, Sb, Zn and Pb anomalies. This broader distribution of Tl in whole-rock and particularly stream sediment samples increases the footprint of exposed and shallowly buried SHMS mineralization. High Tl concentrations also distinguish SHMS mineralization from the vein-breccia deposits, as the latter lack high concentrations of Tl but can otherwise have similar trace-element signatures to SHMS deposits. ?? 2009 AAG/Geological Society of London.

  18. Academic Self-Concepts in Ability Streams: Considering Domain Specificity and Same-Stream Peers

    Science.gov (United States)

    Liem, Gregory Arief D.; McInerney, Dennis M.; Yeung, Alexander S.

    2015-01-01

    The study examined the relations between academic achievement and self-concepts in a sample of 1,067 seventh-grade students from 3 core ability streams in Singapore secondary education. Although between-stream differences in achievement were large, between-stream differences in academic self-concepts were negligible. Within each stream, levels of…

  19. The role of observer variation in determining Rosgen stream types in northeastern Oregon mountain streams

    Science.gov (United States)

    Brett B. Roper; John M. Buffington; Eric Archer; Chris Moyer; Mike Ward

    2008-01-01

    Consistency in determining Rosgen stream types was evaluated in 12 streams within the John Day Basin, northeastern Oregon. The Rosgen classification system is commonly used in the western United States and is based on the measurement of five stream attributes: entrenchment ratio, width-to-depth ratio, sinuosity, slope, and substrate size. Streams were classified from...

  20. The long term response of stream flow to climatic warming in headwater streams of interior Alaska

    Science.gov (United States)

    Jeremy B. Jones; Amanda J. Rinehart

    2010-01-01

    Warming in the boreal forest of interior Alaska will have fundamental impacts on stream ecosystems through changes in stream hydrology resulting from upslope loss of permafrost, alteration of availability of soil moisture, and the distribution of vegetation. We examined stream flow in three headwater streams of the Caribou-Poker Creeks Research Watershed (CPCRW) in...

  1. Logging-related increases in stream density in a northern California watershed

    Science.gov (United States)

    Matthew S. Buffleben

    2012-01-01

    Although many sediment budgets estimate the effects of logging, few have considered the potential impact of timber harvesting on stream density. Failure to consider changes in stream density could lead to large errors in the sediment budget, particularly between the allocation of natural and anthropogenic sources of sediment.This study...

  2. Quality scalable video data stream

    OpenAIRE

    Wiegand, T.; Kirchhoffer, H.; Schwarz, H

    2008-01-01

    An apparatus for generating a quality-scalable video data stream (36) is described which comprises means (42) for coding a video signal (18) using block-wise transformation to obtain transform blocks (146, 148) of transformation coefficient values for a picture (140) of the video signal, a predetermined scan order (154, 156, 164, 166) with possible scan positions being defined among the transformation coefficient values within the transform blocks so that in each transform block, for each pos...

  3. StreamStats, version 4

    Science.gov (United States)

    Ries, Kernell G.; Newson, Jeremy K.; Smith, Martyn J.; Guthrie, John D.; Steeves, Peter A.; Haluska, Tana L.; Kolb, Katharine R.; Thompson, Ryan F.; Santoro, Richard D.; Vraga, Hans W.

    2017-10-30

    IntroductionStreamStats version 4, available at https://streamstats.usgs.gov, is a map-based web application that provides an assortment of analytical tools that are useful for water-resources planning and management, and engineering purposes. Developed by the U.S. Geological Survey (USGS), the primary purpose of StreamStats is to provide estimates of streamflow statistics for user-selected ungaged sites on streams and for USGS streamgages, which are locations where streamflow data are collected.Streamflow statistics, such as the 1-percent flood, the mean flow, and the 7-day 10-year low flow, are used by engineers, land managers, biologists, and many others to help guide decisions in their everyday work. For example, estimates of the 1-percent flood (which is exceeded, on average, once in 100 years and has a 1-percent chance of exceedance in any year) are used to create flood-plain maps that form the basis for setting insurance rates and land-use zoning. This and other streamflow statistics also are used for dam, bridge, and culvert design; water-supply planning and management; permitting of water withdrawals and wastewater and industrial discharges; hydropower facility design and regulation; and setting of minimum allowed streamflows to protect freshwater ecosystems. Streamflow statistics can be computed from available data at USGS streamgages depending on the type of data collected at the stations. Most often, however, streamflow statistics are needed at ungaged sites, where no streamflow data are available to determine the statistics.

  4. Streaming potential of superhydrophobic microchannels.

    Science.gov (United States)

    Park, Hung Mok; Kim, Damoa; Kim, Se Young

    2017-03-01

    For the purpose of gaining larger streaming potential, it has been suggested to employ superhydrophobic microchannels with a large velocity slip. There are two kinds of superhydrophobic surfaces, one having a smooth wall with a large Navier slip coefficient caused by the hydrophobicity of the wall material, and the other having a periodic array of no- shear slots of air pockets embedded in a nonslip wall. The electrokinetic flows over these two superhydrophobic surfaces are modelled using the Navier-Stokes equation and convection-diffusion equations of the ionic species. The Navier slip coefficient of the first kind surfaces and the no-shear slot ratio of the second kind surfaces are similar in the sense that the volumetric flow rate increases as these parameter values increase. However, although the streaming potential increases monotonically with respect to the Navier slip coefficient, it reaches a maximum and afterward decreases as the no-shear ratio increases. The results of the present investigation imply that the characterization of superhydrophobic surfaces employing only the measurement of volumetric flow rate against pressure drop is not appropriate and the fine structure of the superhydrophobic surfaces must be verified before predicting the streaming potential and electrokinetic flows accurately. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Seasonal synchronicity of algal assemblages in three Midwestern agricultural streams having varying concentrations of atrazine, nutrients, and sediment.

    Science.gov (United States)

    Andrus, J Malia; Winter, Diane; Scanlan, Michael; Sullivan, Sean; Bollman, Wease; Waggoner, J B; Hosmer, Alan J; Brain, Richard A

    2013-08-01

    Numerous studies characterizing the potential effects of atrazine on algal assemblages have been conducted using micro- or mesocosms; however, few evaluations focused on in situ lotic algal communities, potentially confounding risk assessment conclusions. This exploratory study, conducted at several sites in the midwestern United States where atrazine is commonly used, presents in situ observations of native algal communities relative to atrazine exposure and other parameters. Planktonic and periphytic algae from three streams in three Midwestern states, having historically differing atrazine levels, were sampled over a 16-week period in 2011 encompassing atrazine applications and the summer algal growth period at each site. Changes in abundance, diversity, and composition of algal communities were placed in the context of hydrological, climatic, and water quality parameters (including components sometimes present in agricultural runoff) also collected during the study. Diatoms dominated communities at each of the three sites and periphyton was much more abundant than phytoplankton. As expected, significant variations in algal community and environmental parameters were observed between sites. However, correspondence analysis plots revealed that patterns of temporal variation in algal communities at each site and in periphyton or phytoplankton were dominated by seasonal environmental gradients. Significant concordance in these seasonal patterns was detected among sites and between phytoplankton and periphyton communities (via procrustes Protest analysis), suggesting synchronicity of algal communities across a regional scale. While atrazine concentrations generally exhibited seasonal trends at the study watersheds; no effects on algal abundance, diversity or assemblage structure were observed as a result of atrazine pulses. This lack of response may be due to exposure events of insufficient concentration or duration (consistent with previously reported results) or

  6. Uranium hydrogeochemical and stream sediment reconnaissance data from the area of the Shishmaref, Kotzebue, Selawik and Shungnak Quadrangles, northern Seward Peninsula and vicinity, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Warren, R.G.; Hill, D.E.; Sharp, R.R. Jr.

    1978-05-01

    During the summer of 1976, 1336 water and 1251 sediment samples were collected for Los Alamos Scientific Laboratory (LASL) from 1356 streams and small lakes or ponds within Shishmaref, Kotzebue, Selawik, and western portion of Shungnak NTMS quadrangles in western Alaska. Both a water and sediment sample were generally obtained from each location at a nominal location density of 1/23 km/sup 2/. Total uranium was measured in waters by fluorometry and in sediments and a few waters by delayed neutron counting at LASL. Uranium concentrations in waters have a mean of 0.31 ppB and a maximum of 9.23 ppB, and sediments exhibit a mean of 3.44 ppM and a maximum of 37.7 ppM. A large number of high-uranium concentrations occur in both water and sediment samples collected in the Selawik Hills. At least two locations within the Selawik Hills appear favorable for further investigation of possible uranium mineralization. A cluster of high-uranium sediments, seen in the Waring Mountains, are probably derived from a lower Cretaceous conglomerate unit which is assocated with known airborne radiometric anomalies. Apparently less favorable areas for further investigation of possible uranium mineralization are also located in the Waring Mountains and Kiana Hills. Additional samples were collected within the Shungnak quadrange to increase the sampling density used elsewhere in the area to about one location per 11 km/sup 2/ (double-density). Contoured plots of uranium concentrations for both waters and sediments were prepared for all double-density sample locations, and then for the even-numbered and odd-numbered locations separately. These plots indicate that the HSSR sampling density of 1/23 km/sup 2/ used in lowland areas of Alaska provide essentially the same definition of relative areal uranium distributions in waters and sediments as seen when the density is doubled. These plots indicate that regional distribution patterns for uranium are well defined without selective sampling of

  7. Global perspectives on the urban stream syndrome

    Science.gov (United States)

    Roy, Allison; Booth, Derek B.; Capps, Krista A.; Smith, Benjamin

    2016-01-01

    Urban streams commonly express degraded physical, chemical, and biological conditions that have been collectively termed the “urban stream syndrome”. The description of the syndrome highlights the broad similarities among these streams relative to their less-impaired counterparts. Awareness of these commonalities has fostered rapid improvements in the management of urban stormwater for the protection of downstream watercourses, but the focus on the similarities among urban streams has obscured meaningful differences among them. Key drivers of stream responses to urbanization can vary greatly among climatological and physiographic regions of the globe, and the differences can be manifested in individual stream channels even through the homogenizing veneer of urban development. We provide examples of differences in natural hydrologic and geologic settings (within similar regions) that can result in different mechanisms of stream ecosystem response to urbanization and, as such, should lead to different management approaches. The idea that all urban streams can be cured using the same treatment is simplistic, but overemphasizing the tremendous differences among natural (or human-altered) systems also can paralyze management. Thoughtful integration of work that recognizes the commonalities of the urban stream syndrome across the globe has benefitted urban stream management. Now we call for a more nuanced understanding of the regional, subregional, and local attributes of any given urban stream and its watershed to advance the physical, chemical, and ecological recovery of these systems.

  8. Estimation of suspended sediment flux in streams using continuous turbidity and flow data coupled with laboratory concentrations

    Science.gov (United States)

    Jack Lewis

    2002-01-01

    The widening use of sediment surrogate measurements such as turbidity necessitates consideration of new methods for estimating sediment flux. Generally, existing methods can be simply be used in new ways. The effectiveness of a method varies according to the quality of the surrogate data and its relation to suspended sediment concentration (SSC). For this discussion,...

  9. Wildfire impacts on stream sedimentation: re-visiting the Boulder Creek Burn in Little Granite Creek, Wyoming, USA

    Science.gov (United States)

    Sandra Ryan; Kathleen Dwire

    2012-01-01

    In this study of a burned watershed in northwestern Wyoming, USA, sedimentation impacts following a moderately-sized fire (Boulder Creek burn, 2000) were evaluated against sediment loads estimated for the period prior to burning. Early observations of suspended sediment yield showed substantially elevated loads (5x) the first year post-fire (2001), followed by less...

  10. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    Science.gov (United States)

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2015-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 datasets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-12 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38 – 69,264 km2). An unrealistically low computed effective density (mass SSC / volumetric SSC) of 1.24 g/ml (95% confidence interval: 1.05-1.45 g/ml) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over 2 orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/ml (range: 2.56-2.87 g/ml, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  11. Water and sediment quality assessment in the Colastiné-Corralito stream system (Santa Fe, Argentina): impact of industry and agriculture on aquatic ecosystems.

    Science.gov (United States)

    Regaldo, Luciana; Gutierrez, María F; Reno, Ulises; Fernández, Viviana; Gervasio, Susana; Repetti, María R; Gagneten, Ana M

    2017-12-22

    The present study focuses on the evaluation of metal (chromium, copper, and lead), arsenic, and pesticide (atrazine and endosulfan) contamination in freshwater streams of one of the most important agricultural and industrial areas of central-eastern Argentina, which has not been reported earlier. The environmental fate of inorganic microcontaminants and pesticides was assessed. Samples were collected monthly for a year. Pesticide concentrations were measured in water; metal and arsenic concentrations were measured in water and sediments, and physicochemical variables were analyzed. In most cases, metals and arsenic in water exceeded the established guideline levels for the protection of aquatic biota: 98 and 56.25% of the samples showed higher levels of Cr and Pb, while 81.25 and 85% of the samples presented higher values for Cu and As, respectively. Cr, Pb, Cu, and As exceeded 181.5 times, 41.6 times, 57.5 times, and 12.9 times, respectively, the guideline level values. In sediment samples, permitted levels were also surpassed by 40% for Pb, 15% for As, 4% for Cu, and 2% for Cr. Geoaccumulation Index (Igeo) demonstrated that most of the sediment samples were highly polluted by Cr and Cu and very seriously polluted by Pb, which indicates progressive deterioration of the sediment quality. Atrazine never exceeded them, but 27% of the 48 water samples contained total endosulfan that surpassed the guidelines. The findings of this study suggest risk to the freshwater biota over prolong periods and possible risk to humans if such type of contaminated water is employed for recreation or human use. Improper disposal of industrial effluents and agricultural runoffs need to be controlled, and proper treatment should be done before disposal to avoid further deterioration of the aquifers of this area.

  12. STREAM

    DEFF Research Database (Denmark)

    Godsk, Mikkel

    This paper presents a flexible model, ‘STREAM’, for transforming higher science education into blended and online learning. The model is inspired by ideas of active and collaborative learning and builds on feedback strategies well-known from Just-in-Time Teaching, Flipped Classroom, and Peer...

  13. Atrazine Concentrations in Stream Water and Streambed Sediment Pore Water in the St. Joseph and Galien River Basins, Michigan and Indiana, May 2001 - September 2003

    National Research Council Canada - National Science Library

    Duris, Joseph W; Reeves, Howard W; Kiesler, James L

    2004-01-01

    The U.S. Geological Survey (USGS) sampled multiple stream sites across the St. Joseph and Galien River Basins to detect and quantify the herbicide atrazine using a field enzyme-linked immunosorbent assay (ELISA) triazine test...

  14. Pacific salmon effects on stream ecosystems: a quantitative synthesis.

    Science.gov (United States)

    Janetski, David J; Chaloner, Dominic T; Tiegs, Scott D; Lamberti, Gary A

    2009-03-01

    Pacific salmon (Oncorhynchus spp.) disturb sediments and fertilize streams with marine-derived nutrients during their annual spawning runs, leading researchers to classify these fish as ecosystem engineers and providers of resource subsidies. While these processes strongly influence the structure and function of salmon streams, the magnitude of salmon influence varies widely across studies. Here, we use meta-analysis to evaluate potential sources of variability among studies in stream ecosystem responses to salmon. Results obtained from 37 publications that collectively included 79 streams revealed positive, but highly inconsistent, overall effects of salmon on dissolved nutrients, sediment biofilm, macroinvertebrates, resident fish, and isotopic enrichment. Variation in these response variables was commonly influenced by salmon biomass, stream discharge, sediment size, and whether studies used artificial carcass treatments or observed a natural spawning run. Dissolved nutrients were positively related to salmon biomass per unit discharge, and the slope of the relationship for natural runs was five to ten times higher than for carcass additions. Mean effects on ammonium and phosphorus were also greater for natural runs than carcass additions, an effect attributable to excretion by live salmon. In contrast, we observed larger positive effects on benthic macroinvertebrates for carcass additions than for natural runs, likely because disturbance by live salmon was absent. Furthermore, benthic macroinvertebrates and biofilm associated with small sediments (salmon while those associated with large sediments (>32 mm) showed a positive response. This comprehensive analysis is the first to quantitatively identify environmental and methodological variables that influence the observed effects of salmon. Identifying sources of variation in salmon-stream interactions is a critical step toward understanding why engineering and subsidy effects vary so dramatically over space and

  15. Permafrost Degradation and Stream Metabolism in the Arctic: The effect of thaw slump sedimentation on biological productivity and water quality in the Selawik River, Northwest Alaska

    Science.gov (United States)

    Calhoun, J. P.; Crosby, B. T.

    2011-12-01

    The Selawik River in northwest Alaska, drains ~12,500 km^2 of tree line spruce forest, upland tundra and lowland wetlands. Along the river corridor, high concentrations of fine sediment from a large, young, active retrogressive thaw slump alter the physical and ecological form and function of the stream. This disturbance impacts the entire downstream river corridor, affecting the viability of fish habitat and quality drinking water that subsistence-based native communities depend on. In anticipated warming scenarios, it can be expected that there will be an increase in both the frequency and magnitude of these permafrost degradation features, increasing the extent to which local villages and ecosystems are affected. Our study aims to improve our physical understanding of this system in order to provide biologists, land managers and city officials improved predictive capabilities. Whole stream metabolism (WSM) combines nutrient cycling and organic matter processing to provide an integrated measure of stream health. We utilized a suite of water quality data including temperature, dissolved oxygen, turbidity, pH, pressure, and conductance to calculate WSM values at two experimental reaches up and downstream of the slump over the past three summers. The immediate effects are large magnitude diurnal increases in turbidity, suppressed dissolved oxygen values, and strong attenuation of photosynthetically active radiation (PAR) with depth. We found from 2010 data that, on average, the waters downstream from the slump were 23 times more turbid, had roughly half the dissolved oxygen, and had 4.7 and 2.7 times lower gross primary production (GPP) and ecosystem respiration (ER) respectively. In the summer of 2011, we collected measurements of terrestrial PAR, subsurface PAR, dissolved oxygen and turbidity at multiple river depths at 5 experimental locations. Though turbidity varied roughly by two orders of magnitude and terrestrial PAR increased 850 times between solar

  16. Mining Subsidence-generated legacy sediments in a Mid-European low-order stream floodplain as an archive for historic human activity and flooding events

    Science.gov (United States)

    Buchty-Lemke, Michael; Lehmkuhl, Frank; Frings, Roy; Henkel, Sebastian; Schwarzbauer, Jan

    2015-04-01

    Legacy sediments, which were deposited as a consequence of mining subsidence in a floodplain area, can be used as an archive for human activity and past flooding. The morphodynamics of the Wurm River, a low-order stream in the Lower Rhine Embayment at the border between Germany and the Netherlands, is significantly influenced by a long colliery history, which caused alterations in the natural river landscape. In addition, substances which are transported via municipal wastewaters as well as contaminants emitted by specific regional industries were deposited in the floodplain sediments. This study aims at the reconstruction of human activity and past flooding events derived from geochemical and sedimentological data for different time slices within the 20st century. The spatial and chronological distribution of contaminants is investigated on the basis of several sections and drilling cores along the middle reaches of the Wurm River. Sections within mining subsidence areas and outside of those are compared regarding their sedimentation rates and element contents. Additional information is gathered from digital terrain models, historical documents such as the Tranchot map (early 19th century), and interviews of contemporary witnesses. Sedimentation rates derived from Cs-137 measurements allow a temporal assignment of the legacy sediments. A section within a segment of the Siegfried Line (Westwall), constructed in 1939, that crosses the Wurm River shows a significant increase in sedimentation rates in contrast to the floodplain area that is unaffected by subsidence processes. Furthermore, source-specific contaminants can be used to refine the stratigraphy, since source and period of emission are known. The evaluation of past flooding events is supported by numerical modeling of flood scenarios, which provides detailed information about flooded areas depending on the discharge, particularly for the areas which are under influence of mining subsidence. Besides the

  17. Associations between trace metals in sediment, water, and guppy, Poecilia reticulata (Peters), from urban streams of Semarang, Indonesia.

    NARCIS (Netherlands)

    Widianarko, B.; van Gestel, C.A.M.; Verweij, R.A.; van Straalen, N.M.

    2000-01-01

    The present study aims to answer the question whether the amount of metal in aquatic biota reflects the concentrations in the sediment and water, and whether the physico-chemical properties of the water and sediment have any influence on the suspected relationship. A study was made of 101 small

  18. Watershed Urbanization Linked to Differences in Stream Bacterial Community Composition

    Directory of Open Access Journals (Sweden)

    Jacob D. Hosen

    2017-08-01

    Full Text Available Urbanization strongly influences headwater stream chemistry and hydrology, but little is known about how these conditions impact bacterial community composition. We predicted that urbanization would impact bacterial community composition, but that stream water column bacterial communities would be most strongly linked to urbanization at a watershed-scale, as measured by impervious cover, while sediment bacterial communities would correlate with environmental conditions at the scale of stream reaches. To test this hypothesis, we determined bacterial community composition in the water column and sediment of headwater streams located across a gradient of watershed impervious cover using high-throughput 16S rRNA gene amplicon sequencing. Alpha diversity metrics did not show a strong response to catchment urbanization, but beta diversity was significantly related to watershed impervious cover with significant differences also found between water column and sediment samples. Samples grouped primarily according to habitat—water column vs. sediment—with a significant response to watershed impervious cover nested within each habitat type. Compositional shifts for communities in urbanized streams indicated an increase in taxa associated with human activity including bacteria from the genus Polynucleobacter, which is widespread, but has been associated with eutrophic conditions in larger water bodies. Another indicator of communities in urbanized streams was an OTU from the genus Gallionella, which is linked to corrosion of water distribution systems. To identify changes in bacterial community interactions, bacterial co-occurrence networks were generated from urban and forested samples. The urbanized co-occurrence network was much smaller and had fewer co-occurrence events per taxon than forested equivalents, indicating a loss of keystone taxa with urbanization. Our results suggest that urbanization has significant impacts on the community composition

  19. Storms, channel changes, and a sediment budget for an urban-suburban stream, Difficult Run, Virginia, USA

    Science.gov (United States)

    Gellis, Allen C.; Myers, Michael; Noe, Gregory; Hupp, Cliff R.; Shenk, Edward; Myers, Luke

    2017-01-01

    Determining erosion and deposition rates in urban-suburban settings and how these processes are affected by large storms is important to understanding geomorphic processes in these landscapes. Sediment yields in the suburban and urban Upper Difficult Run are among the highest ever recorded in the Chesapeake Bay watershed, ranging from 161 to 376 Mg/km2/y. Erosion and deposition of streambanks, channel bed, and bars and deposition of floodplains were monitored between 1 March 2010 and 18 January 2013 in Upper Difficult Run, Virginia, USA. We documented the effects of two large storms, Tropical Storm Lee (September 2011), a 100-year event, and Super Storm Sandy (October 2012) a 5-year event, on channel erosion and deposition. Variability in erosion and deposition rates for all geomorphic features, temporally and spatially, are important conclusions of this study. Tropical Storm Lee was an erosive event, where erosion occurred on 82% of all streambanks and where 88% of streambanks that were aggrading before Tropical Storm Lee became erosional. Statistical analysis indicated that drainage area explains linear changes (cm/y) in eroding streambanks and that channel top width explains cross-sectional area changes (cm2/y) in eroding streambanks and floodplain deposition (mm/y). A quasi-sediment budget constructed for the study period using the streambanks, channel bed, channel bars, and floodplain measurements underestimated the measured suspended-sediment load by 61% (2130 Mg/y). Underestimation of the sediment load may be caused by measurement errors and to contributions from upland sediment sources, which were not measured but estimated at 36% of the gross input of sediment. Eroding streambanks contributed 42% of the gross input of sediment and accounted for 70% of the measured suspended-sediment load. Similar to other urban watersheds, the large percentage of impervious area in Difficult Run and direct runoff of precipitation leads to increased streamflow and

  20. Impact of papyrus wetland encroachment on spatial and temporal variabilities of stream flow and sediment export from wet tropical catchments.

    Science.gov (United States)

    Ryken, N; Vanmaercke, M; Wanyama, J; Isabirye, M; Vanonckelen, S; Deckers, J; Poesen, J

    2015-04-01

    During the past decades, land use change in the Lake Victoria basin has significantly increased the sediment fluxes to the lake. These sediments as well as their associated nutrients and pollutants affect the food and water security of millions of people in one of Africa's most densely populated regions. Adequate catchment management strategies, based on a thorough understanding of the factors controlling runoff and sediment discharge are therefore crucial. Nonetheless, studies on the magnitude and dynamics of runoff and sediment discharge are very scarce for the Lake Victoria basin and the African Rift region. We therefore conducted runoff discharge and sediment export measurements in the Upper Rwizi, a catchment in Southwest Uganda, which is representative for the Lake Victoria basin. Land use in this catchment is characterized by grazing area on the high plateaus, banana cropping on the slopes and Cyperus papyrus L. wetlands in the valley bottoms. Due to an increasing population pressure, these papyrus wetlands are currently encroached and transformed into pasture and cropland. Seven subcatchments (358 km2-2120 km2), with different degrees of wetland encroachment, were monitored during the hydrological year June 2009-May 2010. Our results indicate that, due to their strong buffering capacity, papyrus wetlands have a first-order control on runoff and sediment discharge. Subcatchments with intact wetlands have a slower rainfall-runoff response, smaller peak runoff discharges, lower rainfall-runoff ratios and significantly smaller suspended sediment concentrations. This is also reflected in the measured annual area-specific suspended sediment yields (SYs): subcatchments with encroached papyrus swamps have SY values that are about three times larger compared to catchments with intact papyrus vegetation (respectively 106-137 ton km(-2) y(-1) versus 34-37 ton km(-2) y(-1)). We therefore argue that protecting and (where possible) rehabilitating these papyrus wetlands

  1. Soil erosion and sediment yield and their relationships with vegetation cover in upper stream of the Yellow River.

    Science.gov (United States)

    Ouyang, Wei; Hao, Fanghua; Skidmore, Andrew K; Toxopeus, A G

    2010-12-15

    Soil erosion is a significant concern when considering regional environmental protection, especially in the Yellow River Basin in China. This study evaluated the temporal-spatial interaction of land cover status with soil erosion characteristics in the Longliu Catchment of China, using the Soil and Water Assessment Tool (SWAT) model. SWAT is a physical hydrological model which uses the RUSLE equation as a sediment algorithm. Considering the spatial and temporal scale of the relationship between soil erosion and sediment yield, simulations were undertaken at monthly and annual temporal scales and basin and sub-basin spatial scales. The corresponding temporal and spatial Normalized Difference Vegetation Index (NDVI) information was summarized from MODIS data, which can integrate regional land cover and climatic features. The SWAT simulation revealed that the annual soil erosion and sediment yield showed similar spatial distribution patterns, but the monthly variation fluctuated significantly. The monthly basin soil erosion varied from almost no erosion load to 3.92 t/ha and the maximum monthly sediment yield was 47,540 tones. The inter-annual simulation focused on the spatial difference and relationship with the corresponding vegetation NDVI value for every sub-basin. It is concluded that, for this continental monsoon climate basin, the higher NDVI vegetation zones prevented sediment transport, but at the same time they also contributed considerable soil erosion. The monthly basin soil erosion and sediment yield both correlated with NDVI, and the determination coefficients of their exponential correlation model were 0.446 and 0.426, respectively. The relationships between soil erosion and sediment yield with vegetation NDVI indicated that the vegetation status has a significant impact on sediment formation and transport. The findings can be used to develop soil erosion conservation programs for the study area. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Hierarchical photo stream segmentation using context

    Science.gov (United States)

    Gong, Bo; Jain, Ramesh

    2008-01-01

    Photo stream segmentation is to segment photo streams into groups, each of which corresponds to an event. Photo stream segmentation can be done with or without prior knowledge of event structure. In this paper, we study the problem by assuming that there is no a priori event model available. Although both context and content information are important for photo stream segmentation, we focus on investigating the usage of context information in this work. We consider different information components of context such as time, location, and optical setting for inexpensive segmentation of photo streams from common users of modern digital camera. As events are hierarchical, we propose to segment photo stream using hierarchical mixture model. We compare the generated hierarchy with that created by users to see how well results can be obtained without knowing the prior event model. We experimented with about 3000 photos from amateur photographers to study the efficacy of the approach for these context information components.

  3. Water Quality of Emet Stream Basin

    Directory of Open Access Journals (Sweden)

    Cem TOKATLI

    2016-08-01

    Full Text Available Emet Stream Basin is one of Turkey's most important river systems and one of the two most important branches of Uluabat Lake (Ramsar Area. The system is under an intensive pressure of agricultural and industrial activities and domestic wastes. In this study, water samples were collected seasonally from eight stations (one of them is on the Kınık Stream, one of them is on the Dursunbey Stream and six of them on the Emet Stream on the Emet Stream Basin. Some lymnological parameters (nitrate nitrogen, nitrite nitrogen, ammonium nitrogen, sulfate, orthophosphate, and BOD5 were determined to evaluate the water quality. The data obtained were evaluated statistically and compared with the limit values reported by various national and international organizations. It was determined that, Emet Stream Basin is exposed to a significant organic pollution. 

  4. Computing time-series suspended-sediment concentrations and loads from in-stream turbidity-sensor and streamflow data

    Science.gov (United States)

    Rasmussen, Patrick P.; Gray, John R.; Glysson, G. Doug; Ziegler, Andrew C.

    2010-01-01

    Over the last decade, use of a method for computing suspended-sediment concentration and loads using turbidity sensors—primarily nephelometry, but also optical backscatter—has proliferated. Because an in- itu turbidity sensor is capa le of measuring turbidity instantaneously, a turbidity time series can be recorded and related directly to time-varying suspended-sediment concentrations. Depending on the suspended-sediment characteristics of the measurement site, this method can be more reliable and, in many cases, a more accurate means for computing suspended-sediment concentrations and loads than traditional U.S. Geological Survey computational methods. Guidelines and procedures for estimating time s ries of suspended-sediment concentration and loading as a function of turbidity and streamflow data have been published in a U.S. Geological Survey Techniques and Methods Report, Book 3, Chapter C4. This paper is a summary of these guidelines and discusses some of the concepts, s atistical procedures, and techniques used to maintain a multiyear suspended sediment time series.

  5. LHCb : The LHCb Turbo stream

    CERN Multimedia

    Puig Navarro, Albert

    2015-01-01

    The LHCb experiment will record an unprecedented dataset of beauty and charm hadron decays during Run II of the LHC, set to take place between 2015 and 2018. A key computing challenge is to store and process this data, which limits the maximum output rate of the LHCb trigger. So far, LHCb has written out a few kHz of events containing the full raw sub-detector data, which are passed through a full offline event reconstruction before being considered for physics analysis. Charm physics in particular is limited by trigger output rate constraints. A new streaming strategy includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the "turbo stream" the trigger will write out a compact summary of "physics" objects containing all information necessary for analyses, and this will allow an increased output rate and thus higher average efficiencies and smaller selection biases. This idea will be commissioned and developed during...

  6. Streaming potential measurements of biosurfaces

    Science.gov (United States)

    Van Wagenen, R. A.; Andrade, J. D.; Hibbs, J. B., Jr.

    1976-01-01

    A technique based on the measurement of streaming potentials has been developed to evaluate the electrokinetic region of the cell periphery. This approach is feasible for cell lines propagated in in-vitro cell cultures in monolayer form. The advantage of this system is that cells may be evaluated in the living state atttached to a substrate; it is not necessary to subject the cells to enzymatic, chemical, or mechanical trauma required to obtain monodisperse suspensions which are then normally evaluated by microelectrophoresis. In this manner, it should be possible to study the influence of substrate and environmental factors on the charge density and potential at the cell periphery. The apparatus and procedure are described as well as some results concerning the electrokinetic potential of borosilicate capillaries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming-potential measurements is discussed. The electrokinetic potential of BALB/c 3T12 fibroblasts has been quantified as a function of pH, ionic strength, glutaraldehyde fixation, and Giemsa staining.

  7. Rivers and streams: Physical setting and adapted biota

    Science.gov (United States)

    Wilzbach, Margaret A.; Cummins, K.W.

    2008-01-01

    Streams and rivers are enormously important, with their ecological, and economic value, greatly outweighing their significance on the landscape. Lotic ecology began in Europe with a focus on the distribution, abundance, and taxonomic composition of aquatic organisms and in North American with a focus on fishery biology. Since 1980, stream/river research has been highly interdisciplinary, involving fishery biologists, aquatic entomologists, algologists, hydrologists, geomorphologists, microbiologists, and terrestrial plant ecologists. Stream and river biota evolved in response to, and in concert with, the physical and chemical setting. Streams/rivers transport water and move sediments to the sea as part of the hydrologic cycle that involves evaporation, plant evapotranspiration, and precipitation. Ephemeral streams flow only in the wettest year, intermittent streams flow predictably every year during capture of surface runoff, and perennial streams flow continuously during wet and dry periods, receiving both stormflow and groundwater baseflow. The lotic biota, for example, algae, macrophytes, benthic invertebrates, and fishes, have evolved adaptations to their running-water setting. Dominant physical features of this setting are current, substrate, and temperature. Key chemical constituents are dissolved gases, dissolved inorganic ions and compounds, particulate inorganic material, particulate organic material, and dissolved organic ions (nitrogen and phosphorus) and compounds.

  8. Permanently Intermittent Streams of the McMurdo Dry Valleys, Antarctica - Extreme Stream Ecosystems Responding to Annual and Intra-seasonal Intermittency

    Science.gov (United States)

    Gooseff, M. N.; Lyons, W. B.; McKnight, D. M.; Jaros, C.; Welch, K. A.; Wlostowski, A. N.

    2016-12-01

    The streams of the McMurdo Dry Valleys (MDVs), Antarctica are fed by glacial melt water for 6-10 weeks per year, and are therefore intermittent on an annual basis. However, because of fluctuations in surface energy balance during the austral summer, they can also experience intermittent flow during the flow season, which is more typical in long streams (>2 km) than short streams (permafrost, though sediments adjacent to the stream thaw to depths of 0.75-1 m in the austral summer. This accommodation space serves as a reservoir that must be saturated prior to flow continuing downstream. Hence, long streams have larger subsurface pore-reservoirs to fill than short streams, leading to greater intra-season intermittency on long streams than short ones. Flow intermittency has significant impacts in the MDV streams, controlling diatom community make up, and altering temporal biogeochemical patterns of streams. These ecosystems are fairly resilient as algal mats in the stream begin metabolism almost immediately after being re-wetted annually. These streams serve as a poor corollary to warm desert intermittent streams as the rewetting periods are fairly consistent in timing and length. This regularity in intermittency is likely the key to the biological resilience of these ecosystems.

  9. A review on data stream classification approaches

    OpenAIRE

    Sajad Homayoun; Marzieh Ahmadzadeh

    2016-01-01

    Stream data is usually in vast volume, changing dynamically, possibly infinite, and containing multi-dimensional features. The attention towards data stream mining is increasing as regards to its presence in wide range of real-world applications, such as e-commerce, banking, sensor data and telecommunication records. Similar to data mining, data stream mining includes classification, clustering, frequent pattern mining etc. techniques; the special focus of this paper is on classification meth...

  10. Apples to Oranges: Comparing Streaming Video Platforms

    OpenAIRE

    Milewski, Steven; Threatt, Monique

    2017-01-01

    Librarians rely on an ever-increasing variety of platforms to deliver streaming video content to our patrons. These two presentations will examine different aspects of video streaming platforms to gain guidance from the comparison of platforms. The first will examine the accessibility compliance of the various video streaming platforms for users with disabilities by examining accessibility features of the platforms. The second will be a comparison of subject usage of two of the larger video s...

  11. Smart Streaming for Online Video Services

    OpenAIRE

    Chen, Liang; Zhou, Yipeng; Chiu, Dah Ming

    2013-01-01

    Bandwidth consumption is a significant concern for online video service providers. Practical video streaming systems usually use some form of HTTP streaming (progressive download) to let users download the video at a faster rate than the video bitrate. Since users may quit before viewing the complete video, however, much of the downloaded video will be "wasted". To the extent that users' departure behavior can be predicted, we develop smart streaming that can be used to improve user QoE with ...

  12. Activity Based Costing in Value Stream Mapping

    OpenAIRE

    S. S. Abuthakeer; P.V. Mohanram; Kumar, G.M.

    2010-01-01

    This paper attempts to integrate Value Stream Map (VSM) with the cost aspects. A value stream map provides a blueprint for implementing lean manufacturing concepts by illustrating information and materials flow in a value stream. The objective of the present work is to integrate the various cost aspects. The idea is to introduce a cost line, which enhances the clarity in decision making. The redesigned map proves to be effective in highlighting the improvement areas, in terms of quantitative ...

  13. Information Behavior on Social Live Streaming Services

    OpenAIRE

    Scheibe, Katrin; Fietkiewicz, Kaja J.; Wolfgang G. Stock

    2016-01-01

    In the last few years, a new type of synchronous social networking services (SNSs) has emerged—social live streaming services (SLSSs). Studying SLSSs is a new and exciting research field in information science. What information behaviors do users of live streaming platforms exhibit? In our empirical study we analyzed information production behavior (i.e., broadcasting) as well as information reception behavior (watching streams and commenting on them). We conducted two quantitative inv...

  14. Protecting and Enhancing River and Stream Continuity

    OpenAIRE

    Jackson, Scott D.; Bowden, Alison; Graber, Brian

    2007-01-01

    As long linear ecosystems, rivers and streams are particularly vulnerable to fragmentation. There is growing concern about the role of road crossings – and especially culverts – in altering habitats and disrupting river and stream continuity. The River and Stream Continuity Project began in the year 2000 with a startup grant from the Massachusetts Watershed Initiative. The University of Massachusetts took the lead in convening a group of people from a variety of agencies and organizations who...

  15. Suspended sediment, turbidity, and stream water temperature in the Sauk River Basin, western Washington, water years 2012-16

    Science.gov (United States)

    Jaeger, Kristin L.; Curran, Christopher A.; Anderson, Scott W.; Morris, Scott T.; Moran, Patrick W.; Reams, Katherine A.

    2017-11-01

    The Sauk River is a federally designated Wild and Scenic River that drains a relatively undisturbed landscape along the western slope of the North Cascade Mountain Range, Washington, which includes the glaciated volcano, Glacier Peak. Naturally high sediment loads characteristic of basins draining volcanoes like Glacier Peak make the Sauk River a dominant contributor of sediment to the downstream main stem river, the Skagit River. Additionally, the Sauk River serves as important spawning and rearing habitat for several salmonid species in the greater Skagit River system. Because of the importance of sediment to morphology, flow-conveyance, and ecosystem condition, there is interest in understanding the magnitude and timing of suspended sediment and turbidity from the Sauk River system and its principal tributaries, the White Chuck and Suiattle Rivers, to the Skagit River.Suspended-sediment measurements, turbidity data, and water temperature data were collected at two U.S. Geological Survey streamgages in the upper and middle reaches of the Sauk River over a 4-year period extending from October 2011 to September 2015, and at a downstream location in the lower river for a 5-year period extending from October 2011 to September 2016. Over the collective 5-year study period, mean annual suspended-sediment loads at the three streamgages on the upper, middle, and lower Sauk River streamgages were 94,200 metric tons (t), 203,000 t, and 940,000 t streamgages, respectively. Fine (smaller than 0.0625 millimeter) total suspended-sediment load averaged 49 percent at the upper Sauk River streamgage, 42 percent at the middle Sauk River streamgage, and 34 percent at the lower Sauk River streamgage.

  16. Building a dynamic value stream mapping

    OpenAIRE

    Shafiq, Umer

    2014-01-01

    Value stream mapping (VSM) is a visualization tool helps to understand processes by using of stream lined work process. The importance of this process is to decrease the activity that does not add value to the final product and in order to increase the efficiency and production.   The purpose of this thesis is to create dynamic value stream maps of a process by using simulation. By creating dynamic value stream maps makes it possible to analyze more complex systems than traditional VSM. Simul...

  17. Sedgeunkedunk Stream channel geometry from 2007-08-15 to 2016-03-30 (NCEI Accession 0152486)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — We are collecting stream channel geometry and bed sediment grain size distribution data at Sedgeunkedunk stream to evaluate physical habitat changes associated with...

  18. The effect of human settlement on the abundance and community structure of ammonia oxidizers in tropical stream sediments

    NARCIS (Netherlands)

    Reis, Mariana De Paula; Ávila, Marcelo; Keijzer, Rosalinde Margriet; Barbosa, Francisco Antônio Rodrigues; Chartone-Souza, Edmar; Nascimento, Andréa; Laanbroek, (Riks) H.J.

    2015-01-01

    BACKGROUND: Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) are a diverse and functionally important group in the nitrogen cycle. Nevertheless, AOA and AOB communities driving this process remain uncharacterized in tropical freshwater sediment. Here, the effect of human

  19. Human settlement as driver of bacterial, but not of archaeal, ammonia oxidizers abundance and community structure in tropical stream sediments

    Directory of Open Access Journals (Sweden)

    Mariana De Paula Reis

    2015-08-01

    Full Text Available Ammonia-oxidizing archaea (AOA and bacteria (AOB are a diverse and functionally important group in the nitrogen cycle. Nevertheless, AOA and AOB communities driving this process remain uncharacterized in tropical freshwater sediment. Here, the effect of human settlement on the AOA and AOB diversity and abundance have been assessed by phylogenetic and quantitative PCR analyses, using archaeal and bacterial amoA and 16S rRNA genes. Overall, each environment contained specific clades of amoA and 16S rRNA genes sequences, suggesting that selective pressures lead to AOA and AOB inhabiting distinct ecological niches. Human settlement activities, as derived from increased metal and mineral nitrogen contents, appear to cause a response among the AOB community, with Nitrosomonas taking advantage over Nitrosospira in impacted environments. We also observed a dominance of AOB over AOA in mining-impacted sediments, suggesting that AOB might be the primary drivers of ammonia oxidation in these sediments. In addition, ammonia concentrations demonstrated to be the driver for the abundance of AOA, with an inversely proportional correlation between them. Our findings also revealed the presence of novel ecotypes of Thaumarchaeota, such as those related to the obligate acidophilic Nitrosotalea devanaterra at ammonia-rich places of circumneutral pH. These data add significant new information regarding AOA and AOB from tropical freshwater sediments, albeit future studies would be required to provide additional insights into the niche differentiation among these microorganisms.

  20. Assessment of urban stream sediment pollutants entering estuaries using chemical analysis and multiple bioassays to characterise biological activities.

    Science.gov (United States)

    Boehler, Svenja; Strecker, Ruben; Heinrich, Patrick; Prochazka, Erik; Northcott, Grant L; Ataria, James M; Leusch, Frederic D L; Braunbeck, Thomas; Tremblay, Louis A

    2017-09-01

    Stormwater contaminants are a major source of often neglected environmental stressors because of the emphasis placed on the management of municipal and industrial wastewaters. Stormwater-derived pollutants in sediments from two New Zealand estuaries was characterised by analytical chemistry and bioassays. Contaminants were extracted from sediment using accelerated solvent extraction (ASE), recovered and concentrated by solid phase extraction (SPE), and analysed for polycyclic aromatic hydrocarbons (PAHs), selected metals, and musk fragrances. The concentrations of PAHs were below the ANZECC Interim Sediment Quality Guideline values while those of lead and zinc exceeded them in some samples. The sediment extracts containing organic contaminants exhibited acute toxicity in the zebrafish fish embryo toxicity (FET) and teratogenicity, induction of biotransformation (EROD activity), and genotoxicity (comet assay) in zebrafish. The potential of the extracts to interact with endocrine signalling processes was assessed by GeneBLAzer reporter gene bioassays and they exhibited estrogenic, androgenic, and anti-progestagenic activities. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. National uranium resource evaluation program: hydrogeochemical and stream sediment reconnaissance basic data for Ely quadrangle, Nevada; Utah

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-15

    Field and laboratory data are presented for 1937 sediment samples from the Ely Quadrangle, Nevada; Utah. The samples were collected by Savannah River Laboratory; laboratory analysis and data reporting were performed by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee.

  2. Stream flow - its estimation, uncertainty and interaction with groundwater and floodplains

    DEFF Research Database (Denmark)

    Poulsen, Jane Bang

    , floodplain hydraulics and sedimentation patterns has been investigated along a restored channel section of Odense stream, Denmark. Collected samples of deposited sediment, organic matter and phosphorus on the floodplain were compared with results from a 2D dynamic flow model. Three stage dependent flow...... examines stream flow – its estimation, uncertainty and interaction with groundwater and floodplains. Impacts of temporally varying hydraulic flow conditions on uncertainties in stream flow estimation have been investigated in the Holtum and Skjern streams, Denmark. Continuous monitoring of stream flow...... velocities was used to detect hydraulic changes in stream roughness and geometry. A stage-velocity-discharge (QHV) relation has been developed which is a new approach for hydrograph estimation that allows for continuous adjustment of the hydrograph according to roughness changes in the stream. Uncertainties...

  3. Analysis of a morphometric indicator subject to abrupt change in the sediment supply in a braided stream: an experimental study

    Science.gov (United States)

    Vito Papa, Daniel; Ancey, Christophe

    2017-04-01

    Braiding is a complex fluvial process in which sediment-laden water flows are split into multiple threads. Thread joining and splitting at the nodes occurs continuously in the floodplain. Understanding how braiding responds to external factors is a key issue. A number of braided-pattern intensity indices have been proposed to characterize the degree of braiding. Due to the inherent complexity of their dynamics braided rivers exhibit a complex morphology that is difficult to study using simple indices. In this study, we propose a series of experiments to investigate the influence of sediment supply in the evolution of the braiding patterns. To that end, we use a set of morphological indicators, including the index proposed by Redolfi et al. (2016). The experiments are carried out in a 4-m-long and 1-m-wide flume. The bed is made of moderately sorted sand grains whose median diameter is 1 mm. A classic braided pattern configuration composed of various channels, confluences and bifurcations is observed. The experiments satisfy the Froude similarity criterion. Each run starts from an initial straight channel with rectangular cross section. After a certain time (approximately 40 hours) the system reaches equilibrium. This equilibrium is then perturbed by suddenly increasing the sediment feeding until a new point of equilibrium is reached (this takes approximately 40 hours again). During the whole run, bed elevation and water height are measured optically using laser sheets projected on the bed surface. Cross sections are calculated at 2 cm intervals from each others. The entire morphology is then obtained from these cross sections every hour. Sediment is feeded at the flume inlet and sediment transport rates are measured every 15 minutes at the flume outlet.

  4. Water-quality assessment of part of the upper Mississippi River basin, Minnesota and Wisconsin: Nitrogen and phosphorus in streams, streambed sediment, and ground water, 1971-94

    Science.gov (United States)

    Kroening, S.E.; Andrews, W.J.

    1997-01-01

    Nitrogen and phosphorus in streams, streambed sediment, and ground water were summarized using data from Federal, state, and local agencies as part of an analysis of historical water-quality data for the Upper Mississippi River Basin study unit of the U.S. Geological Survey's National Water-Quality Assessment Program. The Upper Mississippi River Basin study unit encompasses the drainage of the Mississippi River from the source to the outlet of Lake Pepin. This report focuses on a 19,500-square-mile study area in the eastern part of the study unit. The study area included the part of the Upper Mississippi River Basin from Royalton, Minnesota, to the outlet of Lake Pepin, located near Red Wing, Minnesota; the Minnesota River Basin from Jordan, Minnesota, to the confluence with the Mississippi River; and the entire drainage basins of the St. Croix, Cannon, and Vermillion Rivers. The Twin Cities metropolitan area, with a population of approximately 2.3 million people, is located in the south-central part of the study area.

  5. Buffer strip width and agricultural pesticide contamination in Danish lowland streams: Implications for stream and riparian management

    DEFF Research Database (Denmark)

    Rasmussen, Jes J.; Baattrup-Pedersen, Annette; Wiberg-Larsen, Peter

    2011-01-01

    According to the European Water Framework Directive, member states are obliged to ensure that all surface water bodies achieve at least good ecological status and to identify major anthropogenic stressors. Non-point source contamination of agricultural pesticides is widely acknowledged as one...... emphasise the importance of considering buffer strips as risk mitigation tools in terms of non-point source pesticide contamination. We furthermore apply our results for discussing the minimum dimensions that vegetated buffer strips should have in order to sufficiently protect stream ecosystems from...... of the most important anthropogenic stressors in stream ecosystems.We surveyed the occurrence of 31 pesticides and evaluated their potential toxicity for benthic macroinvertebrates using Toxic Units (TU) in 14 Danish 1st-and 2nd-order streams in bed sediments and stream water during storm flow and base flow...

  6. Uranium Hydrogeochemical and Stream Sediment Reconnaissance data from the area of the Teller, Bendeleben, Candle, and Kateel River Quadrangles, Seward Peninsula and vicinity, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R.R. Jr.; Hill, D.E.

    1978-05-01

    During July-August 1976, 2026 natural waters and 2085 bottom sediments were collected from 2209 sample locations (at a nominal density of one location each 23 km/sup 2/) on streams and small lakes throughout the Teller, Bendeleben, Candle, and western one-third of the Kateel River NTMS quadrangles, Alaska. Total uranium was measured in the waters by fluorometry and in the sediments and a few waters by delayed-neutron counting. The uranium content of the waters ranged from below the detection limit of 0.02 parts per billion (ppB) to a high of 14.50 ppB, averaging 0.44 ppB, and that of the sediments ranged from a low of 0.2 parts per million (ppM) to a high of 107.4 ppM, averaing 3.93 ppM. The uranium data for water and sediment are separately presented--as computer listings that include pertinent field measurements from each location, as graphically portrayed concentration overlays at 1:250,000 scale for each quadrangle, and as reduced figures showing contours drawn at various concentration levels for each quadrangle--and their areal distributions are compared and correlated with the known features and uranium showings. A test of increasingly detailed methods of data evaluation shows that the more extensive the evaluation, the more useful the reconnaissance uranium data are likely to be. The validity and potential usefulness of the HSSR uranium data are conclusively substantiated by the fact that evidence of all 23 of the reported uranium showings in the 50,000-km/sup 2/ study area can be discerned. Several new locations of interest for further field investigation are identified in each of the quadrangles, and most notably in the Bendeleben Mountains. However, the data presented would appear equally useful in guiding field investigation around the uranium occurrences already known, as noteworthy samples often come from close by but on tributary drainages adjacent, opposite, or above them.

  7. InSTREAM: the individual-based stream trout research and environmental assessment model

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Stephen K. Jackson; Roland H. Lamberson

    2009-01-01

    This report documents Version 4.2 of InSTREAM, including its formulation, software, and application to research and management problems. InSTREAM is a simulation model designed to understand how stream and river salmonid populations respond to habitat alteration, including altered flow, temperature, and turbidity regimes and changes in channel morphology. The model...

  8. Stream invertebrate productivity linked to forest subsidies: 37 stream-years of reference and experimental data

    Science.gov (United States)

    J. Bruce Wallace; Susan L Eggert; Judy L. Meyer; Jackson R. Webster

    2015-01-01

    Riparian habitats provide detrital subsidies of varying quantities and qualities to recipient ecosystems. We used long-term data from three reference streams (covering 24 stream-years) and 13-year whole-stream organic matter manipulations to investigate the influence of terrestrial detrital quantity and quality on benthic invertebrate community structure, abundance,...

  9. The ventral stream offers more affordance and the dorsal stream more memory than believed

    NARCIS (Netherlands)

    Postma, Albert; van der Lubbe, Robert Henricus Johannes; Zuidhoek, Sander

    2002-01-01

    Opposed to Norman's proposal, processing of affordance is likely to occur not solely in the dorsal stream but also in the ventral stream. Moreover, the dorsal stream might do more than just serve an important role in motor actions. It supports egocentric location coding as well. As such, it would

  10. Incremental learning from stream data.

    Science.gov (United States)

    He, Haibo; Chen, Sheng; Li, Kang; Xu, Xin

    2011-12-01

    Recent years have witnessed an incredibly increasing interest in the topic of incremental learning. Unlike conventional machine learning situations, data flow targeted by incremental learning becomes available continuously over time. Accordingly, it is desirable to be able to abandon the traditional assumption of the availability of representative training data during the training period to develop decision boundaries. Under scenarios of continuous data flow, the challenge is how to transform the vast amount of stream raw data into information and knowledge representation, and accumulate experience over time to support future decision-making process. In this paper, we propose a general adaptive incremental learning framework named ADAIN that is capable of learning from continuous raw data, accumulating experience over time, and using such knowledge to improve future learning and prediction performance. Detailed system level architecture and design strategies are presented in this paper. Simulation results over several real-world data sets are used to validate the effectiveness of this method.

  11. Robust Watermarking of Video Streams

    Directory of Open Access Journals (Sweden)

    T. Polyák

    2006-01-01

    Full Text Available In the past few years there has been an explosion in the use of digital video data. Many people have personal computers at home, and with the help of the Internet users can easily share video files on their computer. This makes possible the unauthorized use of digital media, and without adequate protection systems the authors and distributors have no means to prevent it.Digital watermarking techniques can help these systems to be more effective by embedding secret data right into the video stream. This makes minor changes in the frames of the video, but these changes are almost imperceptible to the human visual system. The embedded information can involve copyright data, access control etc. A robust watermark is resistant to various distortions of the video, so it cannot be removed without affecting the quality of the host medium. In this paper I propose a video watermarking scheme that fulfills the requirements of a robust watermark. 

  12. What Can Hierarchies Do for Data Streams?

    DEFF Research Database (Denmark)

    Yin, Xuepeng; Pedersen, Torben Bach

    2007-01-01

    Abstract. Much effort has been put into building data streams management systems for querying data streams. However, the query languages have mostly been SQL-based and aimed for low-level analysis of base data; therefore, there has been little work on supporting OLAP-like queries that provide real...

  13. Flooding in ephemeral streams: incorporating transmission losses

    Science.gov (United States)

    Stream flow in semiarid lands commonly occurs as a form of flash floods in dry ephemeral stream beds. The goal of this research is to couple hydrological and hydraulic models treats channel transmission losses and test the methodology in the USDA-ARS Walnut Gulch Experimental Watershed (WGEW). For h...

  14. Streaming for Mathematics in Victorian Secondary Schools

    Science.gov (United States)

    Forgasz, Helen

    2010-01-01

    Streaming (or ability grouping) for mathematics learning is a contentious issue. It can also be considered an issue of equity or social justice as some students may be adversely affected by the practice. Currently, the Victorian Department of Education and Early Childhood Development (DEECD) does not appear to have clear guidelines on streaming.…

  15. Acoustic streaming enhanced electrodeposition of nickel

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl; Møller, Per

    2003-01-01

    surface was observed. A theory based on mechanical interaction between organic additives adhering to the cathode surface and ultrasonically induced streaming- phenomena is presented here to account for the observed uniform filling behaviour. The present study further indicates a correlation between fringe......-patterns on the surface of the deposit and near-boundary acoustic streaming....

  16. Coldwater fish in wadeable streams [Chapter 8

    Science.gov (United States)

    Jason B. Dunham; Amanda E. Rosenberger; Russell F. Thurow; C. Andrew Dolloff; Philip J. Howell

    2009-01-01

    Small, wadeable streams comprise the majority of habitats available to fishes in fluvial networks. Wadeable streams are generally less than 1 m deep, and fish can be sampled without the use of water craft. Cold waters are defined as having mean 7-d summer maximum water temperatures of less than 20°C and providing habitat for coldwater fishes.

  17. Effects of Context on Auditory Stream Segregation

    Science.gov (United States)

    Snyder, Joel S.; Carter, Olivia L.; Lee, Suh-Kyung; Hannon, Erin E.; Alain, Claude

    2008-01-01

    The authors examined the effect of preceding context on auditory stream segregation. Low tones (A), high tones (B), and silences (-) were presented in an ABA-pattern. Participants indicated whether they perceived 1 or 2 streams of tones. The A tone frequency was fixed, and the B tone was the same as the A tone or had 1 of 3 higher frequencies.…

  18. Organism-substrate relationships in lowland streams

    NARCIS (Netherlands)

    Tolkamp, H.H.

    1980-01-01

    A field and laboratory study on the microdistribution of bottom dwelling macroinvertebrates to investigate the role of the stream substrate In the development and preservation of the macroinvertebrate communities in natural, undisturbed lowland streams is described. Field data on bottom substrates

  19. Functional measures of stream impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hill, B.H. [Environmental Protection Agency, Cincinnati, OH (United States)

    1994-12-31

    The effects of elevated metals (primarily Zn) in a Rocky Mountain stream were assessed using measures of primary productivity, community respiration, and phosphatase activity. Primary productivity was measured as rates of mass and chlorophyll a accumulation on ceramic tiles, and as O{sub 2}, evolution from natural substrates incubated in situ in closed chambers. Community respiration was measured in situ by incubating fine-grained sediments, collected and composited along each stream study reach, in closed chambers and measuring O{sub 2} depletion. Alkaline and acid phosphatase activity were measured for periphyton scraped from ceramic tiles and natural substrates. Primary productivity, measured as chlorophyll accretion rates and O{sup 2} evolution, were depressed by increasing Zn concentrations. Productivity measured as mass accretion rates did not show significant Zn effects. Community respiration was depressed by increasing Zn concentrations, as was alkaline phosphatase activity. Acid phosphatase activity was higher at the more impacted sites. Overall, functional measures were able to discern those sites receiving greater metal impacts from less impacted sites.

  20. Toxic elements in the stream sediments of an urbanized basin, Eastern China: urbanization greatly elevates their adverse biological effects.

    Science.gov (United States)

    Wu, Pengbao; Yin, Aijing; Yang, Xiaohui; Zhang, Huan; Fan, Manman; Gao, Chao

    2017-04-01

    The concentration of toxic elements (Hg, Cd, Cr, Cu, Pb, Zn, Ni and As) was measured in the sediments of the Qinhuai River in Eastern China along a rural to urban gradient. Multiple approaches were undertaken to evaluate the degree of enrichment and adverse biological effects of these elements. The results showed that the concentration of Hg, Cd, Zn, Cu and Pb increased exponentially from the agricultural headwater to the urbanized downstream, which reflects a severe anthropogenic influence. In addition, area-specific references, such as the local soil background (LSB) and upper continental crust (UCC) derived from the Yangtze craton, were more applicable for evaluating the enrichment of toxic elements in the Qinhuai River than was global UCC. In addition, Cd and Hg had the highest enrichment factor values (EF, with averages of 9.18 and 7.14, respectively); Zn, Pb and Cu had moderate EFs (averages from 1.52 to 2.40), while the average EFs of Ni, Cr and As were approximately equal to 1. Based on consensus-based sediment quality guidelines (SQGs), the contamination characteristics of all of the samples studied were associated with low to moderate priority of adverse biological effects (ABEs) in the rural upstream area, while it was associated with a high to moderate priority of ABEs in the urban sections of the Qinhuai River. Our results suggest that the adverse biological effects of elevated levels of toxic elements were strongly related to the degree of anthropogenic pollution.

  1. StreamExplorer: A Multi-Stage System for Visually Exploring Events in Social Streams.

    Science.gov (United States)

    Wu, Yingcai; Chen, Zhutian; Sun, Guodao; Xie, Xiao; Cao, Nan; Liu, Shixia; Cui, Weiwei

    2017-10-18

    Analyzing social streams is important for many applications, such as crisis management. However, the considerable diversity, increasing volume, and high dynamics of social streams of large events continue to be significant challenges that must be overcome to ensure effective exploration. We propose a novel framework by which to handle complex social streams on a budget PC. This framework features two components: 1) an online method to detect important time periods (i.e., subevents), and 2) a tailored GPU-assisted Self-Organizing Map (SOM) method, which clusters the tweets of subevents stably and efficiently. Based on the framework, we present StreamExplorer to facilitate the visual analysis, tracking, and comparison of a social stream at three levels. At a macroscopic level, StreamExplorer uses a new glyph-based timeline visualization, which presents a quick multi-faceted overview of the ebb and flow of a social stream. At a mesoscopic level, a map visualization is employed to visually summarize the social stream from either a topical or geographical aspect. At a microscopic level, users can employ interactive lenses to visually examine and explore the social stream from different perspectives. Two case studies and a task-based evaluation are used to demonstrate the effectiveness and usefulness of StreamExplorer.Analyzing social streams is important for many applications, such as crisis management. However, the considerable diversity, increasing volume, and high dynamics of social streams of large events continue to be significant challenges that must be overcome to ensure effective exploration. We propose a novel framework by which to handle complex social streams on a budget PC. This framework features two components: 1) an online method to detect important time periods (i.e., subevents), and 2) a tailored GPU-assisted Self-Organizing Map (SOM) method, which clusters the tweets of subevents stably and efficiently. Based on the framework, we present Stream

  2. Buffer strip width and agricultural pesticide contamination in Danish lowland streams: Implications for stream and riparian management

    DEFF Research Database (Denmark)

    Rasmussen, Jes; Baattrup-Pedersen, Annette; Wiberg-Larsen, Peter

    . According to the WFD, member states are obliged to obtain good ecosystem quality in natural surface waters in 2015. Mitigating the risk of non-point source contamination by agricultural pesticides is therefore an essential management task in river basins. Recently, the SPEAR index was introduced for German...... the most important environmental parameters governing the occurrence of agricultural pesticides in Danish streams. We measured the concentration of 23 selected agricultural pesticides in 15 Danish 1st and 2nd order streams. Water samples (storm flow) and sediment samples (bed sediment) were collected...... to the SPEAR index and estimate a minimum BSW required to mitigate effects of pesticide contamination in lowland streams in rural areas....

  3. Effects of All-Terrain Vehicles on Stream Dynamics

    Science.gov (United States)

    Anne Chin; Deven M. Rohrer; Daniel A. Marion; J. Alan Clingenpeel

    2004-01-01

    Abstract - This paper reports preliminary results from research conducted in the Ouachita National Forest to assess the effects of all-terrain vehicle (ATV) trails on stream characteristics. The study focuses on the Wolf Pen Gap Trail that has been in use since 1991. We examine whether that the trail system has caused increased sediment input to and...

  4. Introduction to stream: An Extensible Framework for Data Stream Clustering Research with R

    Directory of Open Access Journals (Sweden)

    Michael Hahsler

    2017-02-01

    Full Text Available In recent years, data streams have become an increasingly important area of research for the computer science, database and statistics communities. Data streams are ordered and potentially unbounded sequences of data points created by a typically non-stationary data generating process. Common data mining tasks associated with data streams include clustering, classification and frequent pattern mining. New algorithms for these types of data are proposed regularly and it is important to evaluate them thoroughly under standardized conditions. In this paper we introduce stream, a research tool that includes modeling and simulating data streams as well as an extensible framework for implementing, interfacing and experimenting with algorithms for various data stream mining tasks. The main advantage of stream is that it seamlessly integrates with the large existing infrastructure provided by R. In addition to data handling, plotting and easy scripting capabilities, R also provides many existing algorithms and enables users to interface code written in many programming languages popular among data mining researchers (e.g., C/C++, Java and Python. In this paper we describe the architecture of stream and focus on its use for data stream clustering research. stream was implemented with extensibility in mind and will be extended in the future to cover additional data stream mining tasks like classification and frequent pattern mining.

  5. StreamMap: Smooth Dynamic Visualization of High-Density Streaming Points.

    Science.gov (United States)

    Li, Chenhui; Baciu, George; Yu, Han

    2017-02-13

    Interactive visualization of streaming points for real-time scatterplots and linear blending of correlation patterns is increasingly becoming the dominant mode of visual analytics for both big data and streaming data from active sensors and broadcasting media. To better visualize and interact with inter-stream patterns, it is generally necessary to smooth out gaps or distortions in the streaming data. Previous approaches either animate the points directly or present a sampled static heatmap. We propose a new approach, called StreamMap, to smoothly blend high-density streaming points and create a visual flow that emphasizes the density pattern distributions. In essence, we present three new contributions for the visualization of high-density streaming points. The first contribution is a density-based method called super kernel density estimation that aggregates streaming points using an adaptive kernel to solve the overlapping problem. The second contribution is a robust density morphing algorithm that generates several smooth intermediate frames for a given pair of frames. The third contribution is a trend representation design that can help convey the flow directions of the streaming points. The experimental results on three datasets demonstrate the effectiveness of StreamMap when dynamic visualization and visual analysis of trend patterns on streaming points are required.

  6. Experimental investigation of acoustic streaming in a cylindrical wave guide up to high streaming Reynolds numbers.

    Science.gov (United States)

    Reyt, Ida; Bailliet, Hélène; Valière, Jean-Christophe

    2014-01-01

    Measurements of streaming velocity are performed by means of Laser Doppler Velocimetry and Particle Image Velociimetry in an experimental apparatus consisting of a cylindrical waveguide having one loudspeaker at each end for high intensity sound levels. The case of high nonlinear Reynolds number ReNL is particularly investigated. The variation of axial streaming velocity with respect to the axial and to the transverse coordinates are compared to available Rayleigh streaming theory. As expected, the measured streaming velocity agrees well with the Rayleigh streaming theory for small ReNL but deviates significantly from such predictions for high ReNL. When the nonlinear Reynolds number is increased, the outer centerline axial streaming velocity gets distorted towards the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes. This kind of behavior is followed by outer streaming cells only and measurements in the near wall region show that inner streaming vortices are less affected by this substantial evolution of fast streaming pattern. Measurements of the transient evolution of streaming velocity provide an additional insight into the evolution of fast streaming.

  7. Simulation of fluid, heat transport to estimate desert stream infiltration

    Science.gov (United States)

    Kulongoski, J.T.; Izbicki, J.A.

    2008-01-01

    In semiarid regions, the contribution of infiltration from intermittent streamflow to ground water recharge may be quantified by comparing simulations of fluid and heat transport beneath stream channels to observed ground temperatures. In addition to quantifying natural recharge, streamflow infiltration estimates provide a means to characterize the physical properties of stream channel sediments and to identify suitable locations for artificial recharge sites. Rates of winter streamflow infiltration along stream channels are estimated based on the cooling effect of infiltrated water on streambed sediments, combined with the simulation of two-dimensional fluid and heat transport using the computer program VS2DH. The cooling effect of ground water is determined by measuring ground temperatures at regular intervals beneath stream channels and nearby channel banks in order to calculate temperature-depth profiles. Additional data inputs included the physical, hydraulic, and thermal properties of unsaturated alluvium, and monthly ground temperatures measurements over an annual cycle. Observed temperatures and simulation results can provide estimates of the minimum threshold for deep infiltration, the variability of infiltration along stream channels, and also the frequency of infiltration events.

  8. Stream Habitat Reach Summary - North Coast [ds63

    Data.gov (United States)

    California Department of Resources — The shapefile is based on habitat unit level data summarized at the stream reach level. The database represents salmonid stream habitat surveys from 645 streams of...

  9. Stream Metabolism and Aquatic Vegetation in Agriculturally Dominated Landscapes

    Science.gov (United States)

    Munn, M. D.; Bales, J. D.; Waite, I.

    2013-12-01

    Forty-six streams across 7 agricultural areas of the United States were assessed using 2-station whole-stream metabolism techniques and aquatic vegetation measurements. Land use was dominated by agriculture, ranging from 0.1 to 92 percent (mean = 44 percent), with agricultural practices ranging from low intensity pasture to high intensity irrigated agriculture. Streams represented a gradient of nutrient concentrations for TN (0.07- 9.0 mg/L) and TP (0.002-1.7 mg/L). Measures of aquatic vegetation included benthic algal biomass (chlorophyll a/m2) and percent macrophyte cover. Additional data included stream and riparian habitat and basin features. Gross primary production (GPP) ranged from 0.1 to 12 g O2/ m2/ d, with highest production occurring in macrophyte-dominated streams in Idaho and Minnesota, and benthic periphyton-dominated streams in the Ozarks (Arkansas and Missouri). GPP was positively correlated with macrophyte cover (r=0.35), but not with algal biomass. Macrophyte driven systems occurred almost exclusively in open canopy systems where canopy was less than 27 percent. Nutrient concentrations in streams were not determined to be important explanatory variables for GPP; however, modeled estimates of nitrogen and phosphorous inputs to the watershed were related to benthic algal biomass and macrophyte cover in specific agricultural areas. Habitat played a key role in GPP, benthic algal biomass, and macrophyte cover, with indicators of light (for example, canopy cover or suspended sediment), often determined to be significant explanatory variables. Approximately 75 percent of sites had negative net ecosystem production indicating heterotrophic metabolism; intensive agriculture dominated many of these streams. Nutrient management strategies in agricultural landscapes require an understanding of nutrient sources, transport mechanisms, habitat condition, and ecosystem processes in order to make sound decisions on land use practices.

  10. High Definition Video Streaming Using H.264 Video Compression

    OpenAIRE

    Bechqito, Yassine

    2009-01-01

    This thesis presents high definition video streaming using H.264 codec implementation. The experiment carried out in this study was done for an offline streaming video but a model for live high definition streaming is introduced, as well. Prior to the actual experiment, this study describes digital media streaming. Also, the different technologies involved in video streaming are covered. These include streaming architecture and a brief overview on H.264 codec as well as high definition t...

  11. Acoustofluidics 14: Applications of acoustic streaming in microfluidic devices.

    Science.gov (United States)

    Wiklund, Martin; Green, Roy; Ohlin, Mathias

    2012-07-21

    In part 14 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we provide a qualitative description of acoustic streaming and review its applications in lab-on-a-chip devices. The paper covers boundary layer driven streaming, including Schlichting and Rayleigh streaming, Eckart streaming in the bulk fluid, cavitation microstreaming and surface-acoustic-wave-driven streaming.

  12. Heterogeneity and Stream-Aquifer Interaction in an Unconsolidated Aquifer

    Science.gov (United States)

    McElwee, C. D.; Healey, J. M.

    2003-12-01

    In north central Kansas the Republican River and its associated alluvial sediments are important regional surface and groundwater supplies. A test site, adjacent to the Republican River, has been established within the porous alluvial sediments to study stream-aquifer interaction and aquifer heterogeneity. This is potentially important research for understanding how to maintain a desired stream flow in the presence of withdrawals from the stream and the aquifer. The site installation consists of seven observation wells located along a line perpendicular to the river channel and centered about a productive irrigation well. In addition to water level data, several geophysical techniques (direct push electrical conductivity, ground penetrating radar, and shallow seismic methods) have been used at this site to characterize the aquifer. The results of the geophysical methods are reported in another paper at this meeting. Water level data collected over a two-week period shows two consecutive irrigation cycles. Each cycle consists of two days of intensive pumping followed by five days of recovery. Several significant elements of stream-aquifer systems can be seen in the data. The water level data demonstrates a regional water level decline in the alluvium that mimics stream gage data located up and down stream from the site, thereby confirming stream-aquifer interaction. Most of the observation wells located symmetrically around the irrigation well show the normal asymmetry expected for a river acting as a specified head boundary. However, heterogeneity causes one pair of symmetric wells to behave differently. Hydraulic data analysis with an automated program (SuprPumpII) demonstrates a degree of heterogeneity within the alluvial sediments not evident from descriptive geologic drilling logs or geophysical logs. A time-drawdown plot of a symmetric pair of observation wells, 310W and 310E, shows an atypical response of the aquifer during early pumping times due to

  13. Morphological assessment of reconstructed lowland streams in the Netherlands

    Science.gov (United States)

    Eekhout, Joris P. C.; Hoitink, Antonius J. F.; de Brouwer, Jan H. F.; Verdonschot, Piet F. M.

    2015-07-01

    Channelisation measures taken halfway the 20th century have had destructive consequences for the diversity of the ecology in the majority of the lowland streams in countries such as the Netherlands. Re-meandering is the common practice in restoring these lowland streams. Three reconstructed streams were monitored during the initial two years after construction of a new channel. The monitoring program included morphological surveys, sediment sampling, habitat pattern surveys, and discharge and water level measurements. Adjustments of the longitudinal bed profile formed the main morphological response. These adjustments were most likely caused by a lack of longitudinal connectivity of the streams as a whole, interrupting transport of sediment at locations of weirs and culverts. Bank erosion was observed only in a limited number of channel bends, and was often related to floodplain heterogeneity. Longitudinal channel bed adjustments and bank erosion were mainly caused by exogenous influences. In channel bends, the cross-sectional shape transformed from trapezoidal to the typical asymmetrical shape as found in meandering rivers. This behaviour can be attributed to an autogenous response to the prevailing flow conditions. Due to the prevailing fine sediment characteristics, bed material is readily set in motion and is being transported during the entire year. The existing design principles fail to address the initial morphological development after reconstruction. An evaluation of pre-set targets to realise water depth and flow velocity ranges shows the current procedures to be deficient. Based on this unfavourable evaluation, and the two-dimensional nature of habitat patterns needed to improve the conditions for stream organisms, we recommend to predict morphological developments as part of the design procedures for lowland stream restoration in the Netherlands.

  14. Acoustic streaming of a sharp edge.

    Science.gov (United States)

    Ovchinnikov, Mikhail; Zhou, Jianbo; Yalamanchili, Satish

    2014-07-01

    Anomalous acoustic streaming is observed emanating from sharp edges of solid bodies that are vibrating in fluids. The streaming velocities can be orders of magnitude higher than expected from the Rayleigh streaming at similar amplitudes of vibration. Acoustic velocity of fluid relative to a solid body diverges at a sharp edge, giving rise to a localized time-independent body force acting on the fluid. This force results in a formation of a localized jet. Two-dimensional numerical simulations are performed to predict acoustic streaming for low amplitude vibration using two methods: (1) Steady-state solution utilizing perturbation theory and (2) direct transient solution of the Navier-Stokes equations. Both analyses agree with each other and correctly predict the streaming of a sharp-edged vibrating blade measured experimentally. The origin of the streaming can be attributed to the centrifugal force of the acoustic fluid flow around a sharp edge. The dependence of this acoustic streaming on frequency and velocity is examined using dimensional analysis. The dependence law is devised and confirmed by numerical simulations.

  15. Network Monitoring as a Streaming Analytics Problem

    KAUST Repository

    Gupta, Arpit

    2016-11-02

    Programmable switches make it easier to perform flexible network monitoring queries at line rate, and scalable stream processors make it possible to fuse data streams to answer more sophisticated queries about the network in real-time. Unfortunately, processing such network monitoring queries at high traffic rates requires both the switches and the stream processors to filter the traffic iteratively and adaptively so as to extract only that traffic that is of interest to the query at hand. Others have network monitoring in the context of streaming; yet, previous work has not closed the loop in a way that allows network operators to perform streaming analytics for network monitoring applications at scale. To achieve this objective, Sonata allows operators to express a network monitoring query by considering each packet as a tuple and efficiently partitioning each query between the switches and the stream processor through iterative refinement. Sonata extracts only the traffic that pertains to each query, ensuring that the stream processor can scale traffic rates of several terabits per second. We show with a simple example query involving DNS reflection attacks and traffic traces from one of the world\\'s largest IXPs that Sonata can capture 95% of all traffic pertaining to the query, while reducing the overall data rate by a factor of about 400 and the number of required counters by four orders of magnitude. Copyright 2016 ACM.

  16. Large wood and in-stream habitat for juvenile coho salmon and larval lampreys in a Pacific Northwest stream

    Science.gov (United States)

    Gonzalez, Rosalinda; Dunham, Jason; Lightcap, Scott W.; McEnroe, Jeffery R.

    2017-01-01

    The influences of large wood on Pacific salmon are well-studied, but studies of nonsalmonid species such as lampreys are uncommon. To address this need, we evaluated the potential effects of large wood on larval lampreys (Pacific Lamprey, Entosphenus tridentatus; and potentially Western Brook Lamprey Lampetra richardsoni), as well as juvenile Coho Salmon Oncorhynchus kisutch, in a small coastal Oregon stream. Our objectives were to 1) identify in-stream habitat characteristics associated with the presence of larval lampreys and abundance of juvenile Coho Salmon; and 2) evaluate how these characteristics were associated with in-stream wood. To address habitat use, we quantified presence of larval lampreys in 92 pools and abundance of juvenile Coho Salmon in 44 pools during summer low flows. We focused on a study reach where large wood was introduced into the stream between 2008 and 2009. Results indicated that presence of larval lampreys was significantly associated with availability of fine sediment and deeper substrate. The abundance of juvenile Coho Salmon (fish/pool) was strongly associated with pool surface area and to a weaker extent with the proportion of cobble and boulder substrates in pools. Pools with wood, regardless of whether they were formed by wood, had significantly greater coverage of fine sediment, deeper substrate, and greater pool surface area. Taken together, these results suggest that in-stream wood can provide habitat associated with presence of larval lampreys and greater abundance of juvenile Coho Salmon.

  17. Visual analysis of stream data

    Science.gov (United States)

    Cheng, Michael; Livny, Miron; Ramakrishnan, Raghu

    1995-04-01

    We present the DEVise (data exploration via visualization environment) toolkit designed for visual exploration of stream data. Data of this type are collected continuously from sources such as remote sensors, program traces, and the stock market. A typical application involves looking for correlations, which may not be precisely defined, by experimenting with graphical representations. This includes selectively comparing data from multiple sources, selective viewing by zooming and scrolling at various resolutions, and querying the underlying data from the graphics. DEVise is designed to provide greater support than packages such as AVS or Khoros for this type of application. First, by abandoning the network flow model of AVS and Khoros in favor of a database query model, we are able to incorporate many performance improvements for visualizing large amounts of data. To our knowledge, this is the first attempt to eliminate data size limitations in a visualization package. Second, by structuring the stand-alone graphics module of most existing tools into user accessible components, users can quickly create, destroy, or interconnect the components to generate new visualizations. This flexibility greatly increases the ease with which users can browse their data. Finally, through limited programming, users can query the underlying data through the graphical representation for more information about the records used to generate the graphical representation.

  18. Value Stream Mapping of Rope Manufacturing: A Case Study

    National Research Council Canada - National Science Library

    Yuvamitra, Korakot; Lee, Jim; Dong, Kanjicai

    2017-01-01

    .... One way of achieving constant process improvement is through value stream mapping. Value stream mapping is used to visualize the current processes for easier understanding and problem identification...

  19. Time-Based Data Streams: Fundamental Concepts for a Data Resource for Streams

    Energy Technology Data Exchange (ETDEWEB)

    Beth A. Plale

    2009-10-10

    Real time data, which we call data streams, are readings from instruments, environmental, bodily or building sensors that are generated at regular intervals and often, due to their volume, need to be processed in real time. Often a single pass is all that can be made on the data, and a decision to discard or keep the instance is made on the spot. Too, the stream is for all practical purposes indefinite, so decisions must be made on incomplete knowledge. This notion of data streams has a different set of issues from a file, for instance, that is byte streamed to a reader. The file is finite, so the byte stream is becomes a processing convenience more than a fundamentally different kind of data. Through the duration of the project we examined three aspects of streaming data: the first, techniques to handle streaming data in a distributed system organized as a collection of web services, the second, the notion of the dashboard and real time controllable analysis constructs in the context of the Fermi Tevatron Beam Position Monitor, and third and finally, we examined provenance collection of stream processing such as might occur as raw observational data flows from the source and undergoes correction, cleaning, and quality control. The impact of this work is severalfold. We were one of the first to advocate that streams had little value unless aggregated, and that notion is now gaining general acceptance. We were one of the first groups to grapple with the notion of provenance of stream data also.

  20. Events and Trends in Text Streams

    Energy Technology Data Exchange (ETDEWEB)

    Engel, David W.; Whitney, Paul D.; Cramer, Nicholas O.

    2010-03-04

    "Text streams--collections of documents or messages that are generated and observed over time--are ubiquitous. Our research and development are targeted at developing algorithms to find and characterize changes in topic within text streams. To date, this research has demonstrated the ability to detect and describe 1) short duration, atypical events and 2) the emergence of longer-term shifts in topical content. This technology has been applied to predefined temporally ordered document collections but is also suitable for application to near-real-time textual data streams."

  1. Two stream instabilities in degenerate quantum plasmas

    CERN Document Server

    Son, S

    2013-01-01

    The quantum mechanical effect on the plasma two-stream instability is studied based on the dielectric function approach. The analysis suggests that the degenerate plasma relevant to the inertial confinement fusion behaves differently from classical plasmas when the electron drift velocity is comparable to the Fermi velocity. For high wave vector comparable to the Fermi wave vector, the degenerate quantum plasma has larger regime of the two-stream instabilities than the classical plasma. A regime, where the plasma waves with the frequency larger than 1.5 times of the Langmuir wave frequency become unstable to the two-stream instabilities, is identified.

  2. EPHEMEROPTERA (INSECTA LIMNOFAUNA OF SULTANSUYU STREAM (MALATYA

    Directory of Open Access Journals (Sweden)

    Caner AYDINLI

    2013-02-01

    Full Text Available A total of 1838 nymph samples from 7 localities in Sultansuyu Stream (Malatya were collectedbetween July-2006 and August-2007 and investigated to determine Ephemeroptera (Insectalimnofauna of the stream. 10 taxa in the species level and 4 taxa in the genus level belonging to 10genera in 6 families were determined (Baetis buceratus, B. lutheri, B. rhodani, B. vernus, Caenismacrura, Cloeon dipterum, C. simile, Ecdyonurus sp., Electrogena sp., Epeorus sp., Ephemera vulgata,Ephemerella ignita, Potamanthus luteus and Rhitrogena sp.. All determined taxa in the genus andspecies level has been new record for Sultansuyu Stream.

  3. Video streaming in the Wild West

    Directory of Open Access Journals (Sweden)

    Helen Gail Prosser

    2006-11-01

    Full Text Available Northern Lakes College in north-central Alberta is the first post-secondary institution in Canada to use the Media on Demand digital video system to stream large video files between dispersed locations (Karlsen. Staff and students at distant locations of Northern Lakes College are now viewing more than 350 videos using video streaming technology. This has been made possible by SuperNet, a high capacity broadband network that connects schools, hospitals, libraries and government offices throughout the province of Alberta (Alberta SuperNet. This article describes the technical process of implementing video streaming at Northern Lakes College from March 2005 until March 2006.

  4. Contaminants in stream sediments from seven United States metropolitan areas: part II--sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus.

    Science.gov (United States)

    Kemble, Nile E; Hardesty, Douglas K; Ingersoll, Christopher G; Kunz, James L; Sibley, Paul K; Calhoun, Daniel L; Gilliom, Robert J; Kuivila, Kathryn M; Nowell, Lisa H; Moran, Patrick W

    2013-01-01

    Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs, OC pesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants.

  5. Contaminants in stream sediments from seven United States metropolitan areas: part II—sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus

    Science.gov (United States)

    Kemble, Nile E.; Hardesty, Douglas K.; Ingersoll, Christopher G.; Kunz, James L.; Sibley, Paul K.; Calhoun, Daniel L.; Gilliom, Robert J.; Kuivila, Kathryn; Nowell, Lisa H.; Moran, Patrick W.

    2013-01-01

    Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs,OCpesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants. Sediments are a repository for many contaminants released into surface waters. Because of this, organisms inhabiting sediments may be exposed to a wide range of contaminants (United States Environmental Protection Agency (USEPA) United States Environmental Protection Agency 2000; American Society for Testing and Materials [ASTM] American Society for Testing and Materials International 2012). Contaminants of potential concern in sediments typically include trace elements (metals

  6. Influence of trophic position and spatial location on polychlorinated biphenyl (PCB) bioaccumulation in a stream food web

    Science.gov (United States)

    David M. Walters; Ken M. Fritz; Brent R. Johnson; James M. Lazorchak; Frank H. McCormick

    2008-01-01

    Bioaccumulation of persistent organic contaminants (OCs) is well documented in lentic and marine ecosystems, but few studies have addressed OC bioaccumulation in streams. The limited research in streams is surprising given the magnitude and extent of OC pollution. Approximately 9% of wadeable stream length in the U.S. is underlain by contaminated sediments including...

  7. Investigation of stream temperature response to non-uniform groundwater discharge in a Danish lowland stream

    DEFF Research Database (Denmark)

    Karthikeyan, Matheswaran; Kastrup Blemmer, Morten; Thorn, P.

    2015-01-01

    Non-uniform groundwater discharge into streams influences temperature, a vital stream physical property recognized for its dominant controls on biological processes in lotic habitats at multiple scales. Understanding such spatially heterogeneous processes and their effects is difficult on the basis...... of stream temperature models often calibrated with discrete temperature measurements. This study focused on examining the effect of groundwater discharge on stream temperature using a physically based stream temperature model calibrated on spatially rich high-resolution temperature measurements....... A distributed temperature sensing (DTS) system with a 1.8-km fibre optic cable was used to collect temperature measurements for every 1m of the reach length at 3-min temporal resolution in the stream Elverdamsåen. The groundwater inflow locations identified using DTS data and 24-h temperature measurements (14...

  8. Watershed impervious cover relative to stream location

    Data.gov (United States)

    U.S. Environmental Protection Agency — Estimates of watershed (12-digit huc) impervious cover and impervious cover near streams and water body shorelines for three dates (2001, 2006, 2011) using NLCD...

  9. Active learning with drifting streaming data.

    Science.gov (United States)

    Zliobaite, Indre; Bifet, Albert; Pfahringer, Bernhard; Holmes, Geoffrey

    2014-01-01

    In learning to classify streaming data, obtaining true labels may require major effort and may incur excessive cost. Active learning focuses on carefully selecting as few labeled instances as possible for learning an accurate predictive model. Streaming data poses additional challenges for active learning, since the data distribution may change over time (concept drift) and models need to adapt. Conventional active learning strategies concentrate on querying the most uncertain instances, which are typically concentrated around the decision boundary. Changes occurring further from the boundary may be missed, and models may fail to adapt. This paper presents a theoretically supported framework for active learning from drifting data streams and develops three active learning strategies for streaming data that explicitly handle concept drift. They are based on uncertainty, dynamic allocation of labeling efforts over time, and randomization of the search space. We empirically demonstrate that these strategies react well to changes that can occur anywhere in the instance space and unexpectedly.

  10. Web Audio/Video Streaming Tool

    Science.gov (United States)

    Guruvadoo, Eranna K.

    2003-01-01

    In order to promote NASA-wide educational outreach program to educate and inform the public of space exploration, NASA, at Kennedy Space Center, is seeking efficient ways to add more contents to the web by streaming audio/video files. This project proposes a high level overview of a framework for the creation, management, and scheduling of audio/video assets over the web. To support short-term goals, the prototype of a web-based tool is designed and demonstrated to automate the process of streaming audio/video files. The tool provides web-enabled users interfaces to manage video assets, create publishable schedules of video assets for streaming, and schedule the streaming events. These operations are performed on user-defined and system-derived metadata of audio/video assets stored in a relational database while the assets reside on separate repository. The prototype tool is designed using ColdFusion 5.0.

  11. TARDEC 30-Year Strategy Value Stream Analysis

    Science.gov (United States)

    2015-07-01

    Management Framework( RMF ) documentation for PMs d. Field Service Reps both CONUS and OCONUS e. Perform Army Interoperability Test Certification...Test Engineers# - Product & Process Quality Assessment and Authorization/Risk Management Framework ( RMF ) TARDEC 30-YEAR STRATEGY VALUE STREAM

  12. Climate change and alpine stream biology

    DEFF Research Database (Denmark)

    Hotaling, Scott; Finn, Debra S.; Joseph Giersch, J.

    2017-01-01

    In alpine regions worldwide, climate change is dramatically altering ecosystems and affecting biodiversity in many ways. For streams, receding alpine glaciers and snowfields, paired with altered precipitation regimes, are driving shifts in hydrology, species distributions, basal resources, and th...

  13. Salt vulnerability assessment methodology for urban streams

    Science.gov (United States)

    Betts, A. R.; Gharabaghi, B.; McBean, E. A.

    2014-09-01

    De-icing agents such as road salts while used for winter road maintenance can cause negative effects on urban stream water quality and drinking water supplies. A new methodology using readily available spatial data to identify Salt Vulnerable Areas (SVAs) for urban streams is used to prioritize implementation of best management practices. The methodology calculates the probable chloride concentration statistics at specified points in the urban stream network and compares the results with known aquatic species exposure tolerance limits to characterize the vulnerability scores. The approach prioritizes implementation of best management practices to areas identified as vulnerable to road salt. The vulnerability assessment is performed on seven sites in four watersheds in the Greater Toronto Area and validated using the Hanlon Creek watershed in Guelph. The mean annual in-stream chloride concentration equation uses readily available spatial data - with province-wide coverage - that can be easily used in any urban watershed.

  14. He'eia Stream Contaminants Study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Potential risk to ecological receptors in He’eia Stream and Wetland was characterized through the use of a food-web model to predict effects to the Hawaiian stilt,...

  15. Authentication for Propulsion Test Streaming Video Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An application was developed that could enforce two-factor authentication for NASA access to the Propulsion Test Streaming Video System.  To gain access to the...

  16. Window Update Patterns in Stream Operators

    Science.gov (United States)

    Patroumpas, Kostas; Sellis, Timos

    Continuous queries applied over nonterminating data streams usually specify windows in order to obtain an evolving -yet restricted- set of tuples and thus provide timely results. Among other typical variants, sliding windows are mostly employed in stream processing engines and several advanced techniques have been suggested for their incremental evaluation. In this paper, we set out to study the existence of monotonic-related semantics in windowing constructs towards a more efficient maintenance of their changing contents. We investigate update patterns observed in common window variants as well as their impact on windowed adaptations of typical operators (like selection, join or aggregation), offering more insight towards design and implementation of stream processing mechanisms. Finally, to demonstrate its significance, this framework is validated for several windowed operations against streaming datasets with simulations at diverse arrival rates and window sizes.

  17. Stream biomonitoring using macroinvertebrates around the globe

    NARCIS (Netherlands)

    Buss, Daniel F.; Carlisle, Daren M.; Chon, Tae Soo; Culp, Joseph; Harding, Jon S.; Keizer-Vlek, H.E.; Robinson, Wayne A.; Strachan, Stephanie; Thirion, Christa; Hughes, Robert M.

    2015-01-01

    Water quality agencies and scientists are increasingly adopting standardized sampling methodologies because of the challenges associated with interpreting data derived from dissimilar protocols. Here, we compare 13 protocols for monitoring streams from different regions and countries around the

  18. Simulated transport of polycyclic aromatic hydrocarbons in artificial streams

    Energy Technology Data Exchange (ETDEWEB)

    Bartell, S.M.; Landrum, P.F.; Giesy, J.P.; Leversee, G.J.

    1981-01-01

    A model was constructed to predict the pattern of flow and accumulation of three polycyclic aromatic hydrocarbons (PAH) (anthracene, naphthalene, and benzo(a)pyrene) in artificial streams located on the Savannah River Plant near Aiken, South Carolina. Predictions were based upon the premise that the fundamental chemistry of individual PAH contains useful information for predictive purposes. Model processes included volatilization, photolysis, sorption to sediments and particulates, and net accumulation by biota. Simulations of anthracene transport were compared to results of an experiment conducted in the streams. The model realistically predicted the concentration of dissolved anthracene through time and space. Photolytic degradation appeared to be a major pathway of anthracene flux from the streams.

  19. What controls channel form in steep mountain streams?

    Science.gov (United States)

    Palucis, M. C.; Lamb, M. P.

    2017-07-01

    Steep mountain streams have channel morphologies that transition from alternate bar to step-pool to cascade with increasing bed slope, which affect stream habitat, flow resistance, and sediment transport. Experimental and theoretical studies suggest that alternate bars form under large channel width-to-depth ratios, step-pools form in near supercritical flow or when channel width is narrow compared to bed grain size, and cascade morphology is related to debris flows. However, the connection between these process variables and bed slope—the apparent dominant variable for natural stream types—is unclear. Combining field data and theory, we find that certain bed slopes have unique channel morphologies because the process variables covary systematically with bed slope. Multiple stable states are predicted for other ranges in bed slope, suggesting that a competition of underlying processes leads to the emergence of the most stable channel form.

  20. Organic waste compounds as contaminants in Milwaukee-area streams

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; Magruder, Christopher; Magruder, Matthew; Bruce, Jennifer L.

    2015-09-22

    Organic waste compounds (OWCs) are ingredients and by-products of common agricultural, industrial, and household substances that can contaminate our streams through sources like urban runoff, sewage overflows, and leaking septic systems. To better understand how OWCs are affecting Milwaukee-area streams, the U.S. Geological Survey, in cooperation with the Milwaukee Metropolitan Sewerage District, conducted a three-year study to investigate the presence and potential toxicity of 69 OWCs in base flow, stormflow, pore water, and sediment at 14 stream sites and 3 Milwaukee harbor locations. This fact sheet summarizes the major findings of this study, including detection frequencies and concentrations, potential toxicity, the prevalence of polycyclic aromatic hydrocarbons (PAHs), and the influence of urbanization.

  1. Effects of anthropogenic silt on aquatic macroinvertebrates and abiotic variables in streams in the Brazilian Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Couceiro, Sheyla Regina Marques; Hamada, Neusa [Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Entomologia, Manaus, AM (Brazil); Forsberg, Bruce Rider [Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Entomologia, Manaus, AM (Brazil); Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Ecologia, Manaus, AM (Brazil); Padovesi-Fonseca, Claudia [Univ. de Brasilia, Dept. de Ecologia, Brasilia, DF (Brazil)

    2010-01-15

    Purpose: While environmental risks associated with petroleum extraction such as oil spills or leaks are relatively well known, little attention has been given to the impacts of silt. The increase in petroleum exploitation in Amazonia has resulted in sediment input to aquatic systems, with impacts on their biodiversity. Here we use a combination of field measurements and statistical analyses to evaluate the impacts of anthropogenic silt derived from the construction of roads, borrow pits, and wells during the terrestrial development of gas and oil, on macroinvertebrate communities in streams of the Urucu Petroleum Province in the Central Brazilian Amazon. Material and methods: Ten impacted and nine non-impacted streams were sampled in January, April, and November of 2007. Macroinvertebrates were sampled along a 100-m continuous reach in each stream at 10-m intervals using a dip net. Abiotic variables including, a siltation index (SI), suspended inorganic sediment (SIS), sediment color index (SCI), suspend organic sediment (SOS), pH, electrical conductivity, dissolved oxygen, temperature, water velocity, channel width, and depth, were measured at three equidistant points in each stream ({proportional_to}30-m intervals). Results and discussion: SI did not differ between impacted and undisturbed streams. SIS was higher and SCI lower (more reddish) in impacted than in non-impacted streams. SCI had a positive and SIS a negative effect on both macroinvertebrate richness and density. SIS and SCI also influenced macrophyte taxonomic composition. In impacted streams, taxonomic richness and density were 1.5 times lower than in non-impacted streams. No taxon was significantly associated with impacted streams. SIS was positively correlated with SOS and electrical conductivity while SCI was negatively correlated with SOS, electrical conductivity, and pH. The lack of difference in SI between impacted and nonimpacted streams suggests that anthropogenic sediment does not accumulate

  2. Hydraulic Aspects of Vegetation Maintanence in Streams

    DEFF Research Database (Denmark)

    Larsen, Torben; Vestergaard, Kristian

    1991-01-01

    This paper describes the importance of the underwater vegetation on Danish streams and some of the consequences of vegetation maintenance. the influence of the weed on the hydraulic conditions is studied through experiments in a smaller stream and the effect of cutting channels through the weed...... is measured. A method for predicting the Manning's n as a function of the discharge conditions is suggested, and also a working hypothesis for predictions of the effect of channel cutting is presented....

  3. Rapid Hydraulic Assessment for Stream Restoration

    Science.gov (United States)

    2016-02-01

    governing equations are often used in conjunction with each other to define the flow characteristics of a given hydraulic phenomenon. The energy equation...Approved for public release; distribution is unlimited. ERDC TN-EMRRP-SR-48 February 2016 Rapid Hydraulic Assessment for Stream Restoration...account the hydraulic conditions of the stream being restored. This is true whether the project involves a few feet of bank stabilization or several

  4. Brugeroplevelse af streaming-tjenesten Netflix

    OpenAIRE

    Leifer, Anders; Frydendahl, Erik Pouret; Nedergaard, Mads Kresten

    2014-01-01

    This paper aims to describe and understand the use of the video streaming service Netflix among younger single females, with the further aim to understand the success of streaming in general and Netflix’s offer as an experience economy based offering in particular. After introducing Netflix through a review of its history and its competitive environment, and establishing the epistemological and methodological framework, the paper presents its empiric part, a qualitative semi-structured int...

  5. Streaming Gibbs Sampling for LDA Model

    OpenAIRE

    Gao, Yang; Chen, Jianfei; Zhu, Jun

    2016-01-01

    Streaming variational Bayes (SVB) is successful in learning LDA models in an online manner. However previous attempts toward developing online Monte-Carlo methods for LDA have little success, often by having much worse perplexity than their batch counterparts. We present a streaming Gibbs sampling (SGS) method, an online extension of the collapsed Gibbs sampling (CGS). Our empirical study shows that SGS can reach similar perplexity as CGS, much better than SVB. Our distributed version of SGS,...

  6. LOFS: Library of Online Streaming Feature Selection

    OpenAIRE

    Yu, Kui; Ding, Wei; Wu, Xindong

    2016-01-01

    As an emerging research direction, online streaming feature selection deals with sequentially added dimensions in a feature space while the number of data instances is fixed. Online streaming feature selection provides a new, complementary algorithmic methodology to enrich online feature selection, especially targets to high dimensionality in big data analytics. This paper introduces the first comprehensive open-source library for use in MATLAB that implements the state-of-the-art algorithms ...

  7. From multimedia stream models to GUI generation

    Science.gov (United States)

    Bescos, Jesus; Martinez, Jose M.; Cisneros, Guillermo

    1997-01-01

    This paper is centered on the description of a model that generalizes multimedia data flows handling including complete behavior and interaction mechanisms, hence allowing full integration of GUIs generation -- GUI components are upgraded to interactive media items -- into the same unified model. It aims to reinforce portability, reusability, and quick development of multimedia applications. A picture of previous and of current state-of-art in multimedia application development clearly shows the need for standard abstractions in this field. Current work in this direction leads to a discussion on generic application structure (objects, semantics, etc.) and on different approaches to reach platform independence and efficient object sharing (formal representation languages, interpreted programming languages, distributed environments, etc.). At this point, we present a basic model based on several stream-based models and implementations on multimedia data flows, and built on the basis of the source-stream-sink paradigm. It follows with a detailed explanation of the unified (common to all media) abstract basic stream from which all monomedia flows (including GUI elements) are derived: stream setting- up (source-sink adaptation, and negotiation), flow control procedure, stream sensibility, behavior pattern, etc. The model presentation ends up with the introduction of the multimedia stream that performs synchronization and inter- stream communication tasks, and channels all sensibility, from/towards its managed streams, and allows for the design of an application generator. Then it deeps into the definition of the abstract class hierarchy that guides the model implementation. Finally, several implementation issues are addressed and some practical achievements are described.

  8. Landscaping Considerations for Urban Stream Restoration Projects

    National Research Council Canada - National Science Library

    Bailey, Pam

    2004-01-01

    ... after restoration and its functionality for public use. The landscaping component of such stream and riparian restoration projects must be emphasized given its importance of visual success and public perception. The purpose of this technical note is to address landscaping considerations associated with urban stream and riparian restoration projects, and provide ideas to managers for enhancing the visual appeal and aesthetic qualities of urban projects.

  9. Side Stream Filtration for Cooling Towers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  10. Neutron streaming studies along JET shielding penetrations

    OpenAIRE

    Stamatelatos Ion E.; Vasilopoulou Theodora; Batistoni Paola; Obryk Barbara; Popovichev Sergey; Naish Jonathan

    2017-01-01

    Neutronic benchmark experiments are carried out at JET aiming to assess the neutronic codes and data used in ITER analysis. Among other activities, experiments are performed in order to validate neutron streaming simulations along long penetrations in the JET shielding configuration. In this work, neutron streaming calculations along the JET personnel entrance maze are presented. Simulations were performed using the MCNP code for Deuterium-Deuterium and Deuterium- Tritium plasma sources. The ...

  11. Video Streaming in the Wild West

    OpenAIRE

    Helen Gail Prosser

    2006-01-01

    Northern Lakes College in north-central Alberta is the first post-secondary institution in Canada to use the Media on Demand digital video system to stream large video files between dispersed locations (Karlsen). Staff and students at distant locations of Northern Lakes College are now viewing more than 350 videos using video streaming technology. This has been made possible by SuperNet, a high capacity broadband network that connects schools, hospitals, libraries and government offices thr...

  12. Effects of unsteady free stream velocity and free stream turbulence on stagnation point heat transfer

    Science.gov (United States)

    Gorla, R. S. R.

    1984-01-01

    The combined effects of transient free stream velocity and free stream turbulence on heat transfer at a stagnation point over a cylinder situated in a crossflow are studied. An eddy diffusivity model was formulated and the governing momentum and energy equations are integrated by means of the steepest descent method. The numerical results for the wall shear stress and heat transfer rate are correlated by a turbulence parameter. The wall friction and heat transfer rate increase with increasing free stream turbulence intensity.

  13. Spatial heterogeneity of within-stream methane concentrations

    Science.gov (United States)

    Crawford, John T.; Loken, Luke C.; West, William E.; Crary, Benjamin; Spawn, Seth A.; Gubbins, Nicholas; Jones, Stuart E.; Striegl, Robert G.; Stanley, Emily H.

    2017-01-01

    Streams, rivers, and other freshwater features may be significant sources of CH4 to the atmosphere. However, high spatial and temporal variabilities hinder our ability to understand the underlying processes of CH4 production and delivery to streams and also challenge the use of scaling approaches across large areas. We studied a stream having high geomorphic variability to assess the underlying scale of CH4 spatial variability and to examine whether the physical structure of a stream can explain the variation in surface CH4. A combination of high-resolution CH4 mapping, a survey of groundwater CH4 concentrations, quantitative analysis of methanogen DNA, and sediment CH4 production potentials illustrates the spatial and geomorphic controls on CH4 emissions to the atmosphere. We observed significant spatial clustering with high CH4 concentrations in organic-rich stream reaches and lake transitions. These sites were also enriched in the methane-producing mcrA gene and had highest CH4 production rates in the laboratory. In contrast, mineral-rich reaches had significantly lower concentrations and had lesser abundances of mcrA. Strong relationships between CH4and the physical structure of this aquatic system, along with high spatial variability, suggest that future investigations will benefit from viewing streams as landscapes, as opposed to ecosystems simply embedded in larger terrestrial mosaics. In light of such high spatial variability, we recommend that future workers evaluate stream networks first by using similar spatial tools in order to build effective sampling programs.

  14. Information Behavior on Social Live Streaming Services

    Directory of Open Access Journals (Sweden)

    Scheibe, Katrin

    2016-06-01

    Full Text Available In the last few years, a new type of synchronous social networking services (SNSs has emerged—social live streaming services (SLSSs. Studying SLSSs is a new and exciting research field in information science. What information behaviors do users of live streaming platforms exhibit? In our empirical study we analyzed information production behavior (i.e., broadcasting as well as information reception behavior (watching streams and commenting on them. We conducted two quantitative investigations, namely an online survey with YouNow users (N = 123 and observations of live streams on YouNow (N = 434. YouNow is a service with video streams mostly made by adolescents for adolescents. YouNow users like to watch streams, to chat while watching, and to reward performers by using emoticons. While broadcasting, there is no anonymity (as in nearly all other WWW services. Synchronous SNSs remind us of the film The Truman Show, as anyone has the chance to consciously broadcast his or her own life real-time.

  15. Multimedia streaming gateway with jitter detection

    Science.gov (United States)

    Chan, Siu-Ping; Kok, Chi-Wah; Wong, Albert K.

    2003-06-01

    This paper investigates a novel active buffer management scheme, "Jitter Detection" (JD) for gateway-based congestion control to stream multimedia traffics in packet-switched networks. The quality of multimedia presentation can be greatly degraded due to network delay variation or jitter when transported over packet-switched network. Jitter degrades the timing relationship among packets in a single media stream and between packets from different media streams and hence creates multimedia synchronization problems. Moreover, too much jitter will also degrade the performance of the streaming buffer in the client. Packets received by client will render useless if they have accumulated a large enough jitter. The proposed active buffer management scheme will improve the quality of service in multimedia networking by detecting and discarding useless packets that accumulated large enough jitter. Such as to maintain a high bandwidth for packets within the multimedia stream's jitter tolerance. Simulation results have shown that the proposed scheme can effectively lower the average received packet jitter and increase the goodput of the received packets when compared to random early detection (RED), and Droptail used in gateway-based congestion control. Furthermore, simulation results have also revealed that the proposed scheme can maintain the same TCP-friendliness when compared to that of RED and Droptail used for multimedia streams.

  16. Prediction of pesticide toxicity in Midwest streams

    Science.gov (United States)

    Shoda, Megan E.; Stone, Wesley W.; Nowell, Lisa H.

    2016-01-01

    The occurrence of pesticide mixtures is common in stream waters of the United States, and the impact of multiple compounds on aquatic organisms is not well understood. Watershed Regressions for Pesticides (WARP) models were developed to predict Pesticide Toxicity Index (PTI) values in unmonitored streams in the Midwest and are referred to as WARP-PTI models. The PTI is a tool for assessing the relative toxicity of pesticide mixtures to fish, benthic invertebrates, and cladocera in stream water. One hundred stream sites in the Midwest were sampled weekly in May through August 2013, and the highest calculated PTI for each site was used as the WARP-PTI model response variable. Watershed characteristics that represent pesticide sources and transport were used as the WARP-PTI model explanatory variables. Three WARP-PTI models—fish, benthic invertebrates, and cladocera—were developed that include watershed characteristics describing toxicity-weighted agricultural use intensity, land use, agricultural management practices, soil properties, precipitation, and hydrologic properties. The models explained between 41 and 48% of the variability in the measured PTI values. WARP-PTI model evaluation with independent data showed reasonable performance with no clear bias. The models were applied to streams in the Midwest to demonstrate extrapolation for a regional assessment to indicate vulnerable streams and to guide more intensive monitoring.

  17. Online feature selection with streaming features.

    Science.gov (United States)

    Wu, Xindong; Yu, Kui; Ding, Wei; Wang, Hao; Zhu, Xingquan

    2013-05-01

    We propose a new online feature selection framework for applications with streaming features where the knowledge of the full feature space is unknown in advance. We define streaming features as features that flow in one by one over time whereas the number of training examples remains fixed. This is in contrast with traditional online learning methods that only deal with sequentially added observations, with little attention being paid to streaming features. The critical challenges for Online Streaming Feature Selection (OSFS) include 1) the continuous growth of feature volumes over time, 2) a large feature space, possibly of unknown or infinite size, and 3) the unavailability of the entire feature set before learning starts. In the paper, we present a novel Online Streaming Feature Selection method to select strongly relevant and nonredundant features on the fly. An efficient Fast-OSFS algorithm is proposed to improve feature selection performance. The proposed algorithms are evaluated extensively on high-dimensional datasets and also with a real-world case study on impact crater detection. Experimental results demonstrate that the algorithms achieve better compactness and higher prediction accuracy than existing streaming feature selection algorithms.

  18. Controlling the acoustic streaming by pulsed ultrasounds.

    Science.gov (United States)

    Hoyos, Mauricio; Castro, Angélica

    2013-01-01

    We propose a technique based on pulsed ultrasounds for controlling, reducing to a minimum observable value the acoustic streaming in closed ultrasonic standing wave fluidic resonators. By modifying the number of pulses and the repetition time it is possible to reduce the velocity of the acoustic streaming with respect to the velocity generated by the continuous ultrasound mode of operation. The acoustic streaming is observed at the nodal plane where a suspension of 800nm latex particles was focused by primary radiation force. A mixture of 800nm and 15μm latex particles has been also used for showing that the acoustic streaming is hardly reduced while primary and secondary forces continue to operate. The parameter we call "pulse mode factor" i.e. the time of applied ultrasound divided by the duty cycle, is found to be the adequate parameter that controls the acoustic streaming. We demonstrate that pulsed ultrasound is more efficient for controlling the acoustic streaming than the variation of the amplitude of the standing waves. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. South Stream Project and the Ukrainian Factor

    Directory of Open Access Journals (Sweden)

    Roxana Ioana Banciu

    2015-03-01

    Full Text Available The paper seeks to develop an analysis of the South Stream project in view of the Ukrainian crisis. We cannot put aside the internal factor as Ukraine is facing serious internal issues such as corruption and instability, therefore Russia’s invasion of Ukraine can not be simply ignored in this pipeline project. The article uses mostly facts that happened throughout last years, as well as for and against declarations in the case of the South Stream project and its mother Russia. When we hear about South Stream, we think of Russia and since 2007, this pipeline has encouraged Putin’s faith in energy superpower. A good point to start with was to gather all declarations since then and cover all actions that regard the South Stream game. In Russian foreign policy for the South Stream race, Soft Power was used more than enough and it has recently made room for Hard Power, which is the Ukraine never ending episode. Insights of the South Stream story have been lately related both softly and hardly, this is the reason why I have chosen to analyse both sides in order to complete the energy landscape.

  20. Effects of unsteady free-stream velocity and free-stream turbulence at a stagnation point

    Science.gov (United States)

    Gorla, R. S. R.

    1982-01-01

    The combined effects of transient free stream velocity and turbulence at a stagnation point on a cylinder situated in a crossflow is investigated analytically, and a model is formulated for the eddy diffusivity induced by free-stream turbulence. The steepest descent method is used to integrate the governing momentum expression, and numerical solutions are given for the unsteady wall shear stress function for specific free-stream transients. It is found after correlation of the results by means of a new turbulence parameter that wall friction increases with increasing free-stream turbulence intensity, and that the friction factor increases with increasing reduced frequency of oscillation values.

  1. Effects of agriculture on wood breakdown and microbial biofilm respiration in southern Appalachian streams

    Science.gov (United States)

    M.E. McTammany; E.F. Benfield; J.R. Webster

    2008-01-01

    Agriculture causes high sediment, nutrient and light input to streams, which may affect rates of ecosystem processes, such as organic matter decay. In the southern Appalachians, socioeconomic trends over the past 50 years have caused widespread abandonment of farmland with subsequent reforestation. Physical and chemical properties of streams in these...

  2. How Do Biota Respond to Additional Physical Restoration of Restored Streams?

    NARCIS (Netherlands)

    Nilsson, Christer; Sarneel, Judith|info:eu-repo/dai/nl/304836923; Palm, Daniel; Gardeström, Johanna; Pilotto, Francesca; Polvi, Lina E.; Lind, L.; Holmqvist, D.; Lundqvist, H.

    2017-01-01

    Restoration of channelized streams by returning coarse sediment from stream edges to the wetted channel has become a common practice in Sweden. Yet, restoration activities do not always result in the return of desired biota. This study evaluated a restoration project in the Vindel River in northern

  3. THE EXTENT OF MINE DRAINAGE INTO STREAMS OF THE CENTRAL APPALACHIAN AND ROCKY MOUNTAIN REGIONS

    Science.gov (United States)

    Runoff and drainage from active and inactive mines are contaminating streams throughout the United States with acidic and metal contaminated waters and sediments. The extent of mining impacts on streams of the coal bearing region of the Central Appalachians and the metal bearing...

  4. Microbial Enzyme Stoichiometry and Nutrient Limitation in US Streams and Rivers

    Science.gov (United States)

    We analyzed water and sediment chemistry, catchment land cover, and extracellular enzymes (ecoenzymes) activities related to microbial C, N, and P acquisition in more than 2100 1st- 10th order streams. Streams were selected from a probability design to represent the entire popula...

  5. Ecoregion and land-use influence invertebrate and detritus transport from headwater streams

    Science.gov (United States)

    Christopher A. Binckley; Mark S. Wipfli; R. Bruce Medhurst; Karl Polivka; Paul Hessburg; R. Brion Salter; Joshua Y. Kill

    2010-01-01

    We quantified the downstream transport of invertebrates, organic matter and inorganic sediment from 60 fishless headwater streams in the Wenatchee River Basin located on the eastern slope of the Cascade Range in Washington, U.S.A. Streams were classified into four groups (each n = 15) based on their position within two ecological subregions (wet and dry) and the extent...

  6. Effects of agriculture on wood breakdown and microbial biofilm respiration in southern Appalachian streams

    Science.gov (United States)

    E.F Benfield McTammany; J.R. Webster

    2008-01-01

    Agriculture causes high sediment, nutrient and light input to streams, which may affect rates of ecosystem processes, such as organic matter decay. In the southern Appalachians, socioeconomic trends over the past 50 years have caused widespread abandonment of farmland with subsequent reforestation. Physical and chemical properties of streams in these reforested areas...

  7. Some security results of the RC4+ stream cipher

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Jha, Sonu

    2015-01-01

    The RC4+ stream cipher was proposed as an alternative to the well known RC4 stream cipher. It was claimed by the authors that this new stream cipher was designed to overcome all the weaknesses reported against the alleged RC4 stream cipher. In the design specifications of RC4+, the authors make u...

  8. Slope failure as an upslope source of stream wood

    Science.gov (United States)

    Daniel. Miller

    2013-01-01

    Large woody debris is recognized as an important component of stream geomorphology and stream ecosystem function, and forest-land management is recognized as an important control on the quantity (and size and species distributions) of wood available for recruitment to streams. Much of the wood present in streams comes from adjacent forests, and riparian management...

  9. RStorm: Developing and Testing Streaming Algorithms in R

    NARCIS (Netherlands)

    Kaptein, M.C.

    2014-01-01

    Streaming data, consisting of indefinitely evolving sequences, are becoming ubiquitous in many branches of science and in various applications. Computer scientists have developed streaming applications such as Storm and the S4 distributed stream computing platform1 to deal with data streams.

  10. RStorm : Developing and testing streaming algorithms in R

    NARCIS (Netherlands)

    Kaptein, M.C.

    2014-01-01

    Streaming data, consisting of indefinitely evolving sequences, are becoming ubiquitous in many branches of science and in various applications. Computer scientists have developed streaming applications such as Storm and the S4 distributed stream computing platform1 to deal with data streams.

  11. The Dawning of the Stream of Aquarius in RAVE

    NARCIS (Netherlands)

    Williams, M. E. K.; Steinmetz, M.; Sharma, S.; Bland-Hawthorn, J.; de Jong, R. S.; Seabroke, G. M.; Helmi, A.; Freeman, K. C.; Binney, J.; Minchev, I.; Bienayme, O.; Campbell, R.; Fulbright, J. P.; Gibson, B. K.; Gilmore, G. F.; Grebel, E. K.; Munari, U.; Navarro, J. F.; Parker, Q. A.; Reid, W.; Siebert, A.; Siviero, A.; Watson, F. G.; Wyse, R. F. G.; Zwitter, T.

    2011-01-01

    We identify a new, nearby (0.5 kpc less than or similar to d less than or similar to 10 kpc) stream in data from the RAdial Velocity Experiment (RAVE). As the majority of stars in the stream lie in the constellation of Aquarius, we name it the Aquarius Stream. We identify 15 members of the stream

  12. THE DAWNING OF THE STREAM OF AQUARIUS IN RAVE

    OpenAIRE

    Williams, M. E. K.; Steinmetz, M.; Sharma, S.; Bland-Hawthorn, J.; de Jong, R. S.; Seabroke, G. M.; Helmi, A.; Freeman, K. C.; Binney, J.; Minchev, I.; Bienayme, O.; Campbell, R.; Fulbright, J. P.; Gibson, B. K.; Gilmore, G. F.

    2011-01-01

    We identify a new, nearby (0.5 < d < 10 kpc) stream in data from the RAdial Velocity Experiment (RAVE). As the majority of stars in the stream lie in the constellation of Aquarius we name it the Aquarius Stream. We identify 15 members of the stream lying between 30 < l < 75 and -70< b

  13. Pyrethroid insecticides in urban salmon streams of the Pacific Northwest

    Energy Technology Data Exchange (ETDEWEB)

    Weston, D.P., E-mail: dweston@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Asbell, A.M., E-mail: aasbell@berkeley.edu [Department of Integrative Biology, University of California, 3060 Valley Life Sciences Bldg., Berkeley, CA 94720-3140 (United States); Hecht, S.A., E-mail: scott.hecht@noaa.gov [NOAA Fisheries, Office of Protected Resources, 510 Desmond Drive S.E., Lacey, WA 98503 (United States); Scholz, N.L., E-mail: nathaniel.scholz@noaa.gov [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Blvd. E., Seattle, WA 98112 (United States); Lydy, M.J., E-mail: mlydy@siu.edu [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, 171 Life Sciences II, Carbondale, IL 62901 (United States)

    2011-10-15

    Urban streams of the Pacific Northwest provide spawning and rearing habitat for a variety of salmon species, and food availability for developing salmon could be adversely affected by pesticide residues in these waterbodies. Sediments from Oregon and Washington streams were sampled to determine if current-use pyrethroid insecticides from residential neighborhoods were reaching aquatic habitats, and if they were at concentrations acutely toxic to sensitive invertebrates. Approximately one-third of the 35 sediment samples contained measurable pyrethroids. Bifenthrin was the pyrethroid of greatest concern with regards to aquatic life toxicity, consistent with prior studies elsewhere. Toxicity to Hyalella azteca and/or Chironomus dilutus was found in two sediment samples at standard testing temperature (23 deg. C), and in one additional sample at a more environmentally realistic temperature (13 deg. C). Given the temperature dependency of pyrethroid toxicity, low temperatures typical of northwest streams can increase the potential for toxicity above that indicated by standard testing protocols. - Highlights: > Salmon-bearing creeks can be adversely impacted by insecticides from urban runoff. > Pyrethroid insecticides were found in one-third of the creeks in Washington and Oregon. > Two creeks contained concentrations acutely lethal to sensitive invertebrates. > Bifenthrin was of greatest concern, though less than in prior studies. > Standard toxicity testing underestimates the ecological risk of pyrethroids. - Pyrethroid insecticides are present in sediments of urban creeks of Oregon and Washington, though less commonly than in studies elsewhere in the U.S.

  14. POLA RASIO KEUANGAN PADA SAAT UP STREAM DAN DOWN STREAM DI INDUSTRI REALESTAT YANG GO PUBLIC

    Directory of Open Access Journals (Sweden)

    David Sukardi Kodrat

    2006-01-01

    Full Text Available This research has purpose to explain differences on indicator financial ratio in up and down stream condition. This research uses real estate industries listed on Jakarta Stock Exchange as a sample. Sample selection is performed based on purposive sampling method with object to gain sample according to the research aim. Based on those criteria, there are 18 companies, which have fulfilling the conditions needed, starting from 1994 until 2002. The classification of business cycle on up and down stream conditions to used stock pricing indexes of property and real estate which calculated by arithmatic mean method. Based on those criteria, the classifications from 1994 until 1997 are represented by up stream condition and from 1998 until 2002 are represented by down stream condition. The result shows indicators: profitability ratios, gross margin ratios, capital turnover ratios, asset to equity ratios, growth ratios, liquidity ratios, leverage ratios, and cash flow ratios are different in up and down stream conditions, both simultaneously and partially. Simultaneously, there is a significant difference between up and down stream condition with wilks lambda of 0,346 and p value of 0,000. This research shows financial ratio indicator has differences on business cycle. Abstract in Bahasa Indonesia : Penelitan ini mempunyai tujuan untuk mengetahui perbedaan indikator rasio keuangan pada kondisi up stream dan down stream. Penelitian ini menggunakan sampel pada industri di sektor properti yang terdaftar di Bursa Efek Jakarta. Pemilihan sampel dalam penelitian ini menggunakan Purposive Sampling yaitu sampel diambil berdasarkan kriteria-kriteria tertentu yang sesuai dengan tujuan penelitian ini. Berdasarkan kriteria tersebut, terdapat 18 perusahaan yang dapat dijadikan sampel mulai tahun 1994 sampai dengan 2002. Untuk menentukan perubahan business cycle pada kondisi up stream dan down stream dilakukan dengan menggunakan indeks harga saham di sektor properti

  15. Impact of Flood Spates on Denitrifying Bacteria in Low Order Streams

    Science.gov (United States)

    Herrman, K.; Stokdyk, J.

    2011-12-01

    The impact of flood events on channel design, macroinvertebrates, and periphyton in stream ecosystems has been well studied. Little is known, however, about how flood spates affect microorganisms found in stream sediments. Denitrifying bacteria are beneficial organisms because they convert nitrates to nitrogen gas. Providing data that describes the impact of flood events on denitrifiers and the time required after the disturbance for the bacteria to recover are crucial in understanding nitrogen dynamics in stream ecosystems. Three low order streams in central Wisconsin, USA are being monitored during several flood spates during July and August of 2011. Discharge is being continuously monitored in all three streams and sediments are being collected before and after several flood events for laboratory assays. Specifically, sediments are being processed for denitrification rates using the acetylene inhibition technique, microbial biomass carbon using chloroform fumigation, and the quantification of denitrifying bacteria (i.e., nirS, nirK, and nosZ genes) using real-time quantitative PCR. Preliminary data show that within 36 hours after a 90 mm rain event, microbial biomass carbon in all three streams (580 μg C g sediment-1) significantly increased (F1,23 = 650 ± 140; p analyzed to determine if these specific bacteria follow a similar pattern or if the bacterial recolonization of stream sediments follows a unique pattern.

  16. MEKANISME SEGMENTASI LAJU BIT PADA DYNAMIC ADAPTIVE STREAMING OVER HTTP (DASH UNTUK APLIKASI VIDEO STREAMING

    Directory of Open Access Journals (Sweden)

    Muhammad Audy Bazly

    2015-12-01

    Full Text Available This paper aims to analyze Internet-based streaming video service in the communication media with variable bit rates. The proposed scheme on Dynamic Adaptive Streaming over HTTP (DASH using the internet network that adapts to the protocol Hyper Text Transfer Protocol (HTTP. DASH technology allows a video in the video segmentation into several packages that will distreamingkan. DASH initial stage is to compress the video source to lower the bit rate video codec uses H.26. Video compressed further in the segmentation using MP4Box generates streaming packets with the specified duration. These packages are assembled into packets in a streaming media format Presentation Description (MPD or known as MPEG-DASH. Streaming video format MPEG-DASH run on a platform with the player bitdash teritegrasi bitcoin. With this scheme, the video will have several variants of the bit rates that gave rise to the concept of scalability of streaming video services on the client side. The main target of the mechanism is smooth the MPEG-DASH streaming video display on the client. The simulation results show that the scheme based scalable video streaming MPEG- DASH able to improve the quality of image display on the client side, where the procedure bufering videos can be made constant and fine for the duration of video views

  17. Comparing Streaming Video and Videotapes: Can Streaming Video Convey Affective Meaning as Well as Videotape?

    Science.gov (United States)

    Cofield, Jay L.

    This study investigated whether or not low-bandwidth streaming video could be useful for affective purposes. A group of 30 students in a cinema course at a public, liberal arts university viewed a 10-minute dramatic video scene by either videotape or low-bandwidth streaming video. They also took a survey to determine their affective responses and…

  18. Negligible in-stream processing of dissolved organic matter in low order boreal streams

    Science.gov (United States)

    Kothawala, Dolly; Ji, Xing; Laudon, Hjalmar; Ågren, Anneli; Futter, Martyn; Köhler, Stephan; Tranvik, Lars

    2016-04-01

    Low order boreal streams have been considered to be reactive interfaces where dissolved organic matter (DOM) enters inland waters from the surrounding catchment soils. Disentangling the relative influence of key environmental factors suspected to influence stream water DOM composition is highly relevant for predicting the reactivity, and fate of terrestrial DOM. Here, we examined changes to DOM composition using optical approaches from 17 boreal streams, ranging from first to fourth order, over 14 months. We identified two specific fluorescing components, which expressed either a clear mire-wetland or forest signature, providing distinct molecular markers of land cover that is typical of the boreal ecozone. In fact, land cover alone explained 49% of the variability in stream DOM composition. In contrast, seasonal fluctuations in hydrology only contributed to minor shifts (8%) in DOM composition. Perhaps most intriguingly, in-stream transformations to DOM composition were undetectable, suggesting that the extent of in-stream processing was negligible. These findings suggest that low order boreal streams act as passive pipes rather than active reactors. Ultimately, we find that that in-stream processing of DOM was restricted by water residence times (less than 2 days). In summary, these results now leave us better equipped to predict where in the landscape, and when during the year, key DOM transformations may occur within the aquatic conduit.

  19. Streaming in Flemish Secondary Schools: Exploring Teachers' Perceptions of and Adaptations to Students in Different Streams

    Science.gov (United States)

    Stevens, Peter A. J.; Vermeersch, Hans

    2010-01-01

    A rich body of research on streaming or tracking conducted mainly in the USA and UK suggests that teachers have lower expectations of students in lower education streams and adapt their curriculum and pedagogy in line with such expectations. Recent large-scale quantitative research conducted in Flanders (Belgium) shows that teachers teaching in…

  20. Feeding association between benthic and nektonic Neotropical stream fishes

    Directory of Open Access Journals (Sweden)

    Fabrício Barreto Teresa

    Full Text Available Following behaviour among Neotropical stream fishes have been scarcely reported. This type of feeding association was observed in a small stream in the upper rio Paraná system between the catfish, Aspidoras fuscoguttatus, acting as a nuclear species, and Knodus moenkhausii, Poecilia reticulata, and Astyanax altiparanae as follower species. Aspidoras fuscoguttatus individuals dug in the bottom during feeding, causing sediment suspension. Their followers picked food items in the "cloud" of suspended particles. Food items of sediment are no longer consumed by the catfish when in suspension, but are still available for K. moenkhausii, P. reticulata and A. altiparanae. Following behaviour is an alternative feeding tactic for these species, which reinforces the general idea of behavioural plasticity among follower species.