Sample records for stream drainage patterns

  1. Fate of Stream-Evaded CO2 in Relation to Air Drainage Patterns in a BC Coastal Douglas-Fir Forest During Pre- and Post-Harvest Periods

    Johnson, M. S.; Hawthorne, I.; Black, T.; Jassal, R. S.


    directions were strongly katabatic, suggesting evaded CO2 from the stream was advecting down gradient and away from the EC flux tower. Under these conditions, stream-evaded CO2 would not be detected by the EC tower. During pre-harvest summer months, nighttime airflows remained down gradient (e.g. katabatic cold-air drainage), while daytime airflows for summer months exhibited anabatic and katabatic conditions, suggesting some stream-evaded CO2 was directed back into the tower footprint during summer days. During post-harvest months, nocturnal airflows remained katabatic and away from the tower. Post-harvest summer daytime airflows were less organized compared with pre-harvest conditions, with a more pronounced anabatic pattern that likely transports stream-evaded CO2 back towards the EC tower footprint throughout summer days. Overall, airflows were predominantly down-gradient and away from the EC tower, suggesting that a large fraction of stream-evaded CO2 from the stream was not detected by the EC system.

  2. Environmental controls on drainage behavior of an ephemeral stream

    Blasch, K.W.; Ferre, T. P. A.; Vrugt, J.A.


    Streambed drainage was measured at the cessation of 26 ephemeral streamflow events in Rillito Creek, Tucson, Arizona from August 2000 to June 2002 using buried time domain reflectometry (TDR) probes. An unusual drainage response was identified, which was characterized by sharp drainage from saturation to near field capacity at each depth with an increased delay between depths. We simulated the drainage response using a variably saturated numerical flow model representing a two-layer system with a high permeability layer overlying a lower permeability layer. Both the observed data and the numerical simulation show a strong correlation between the drainage velocity and the temperature of the stream water. A linear combination of temperature and the no-flow period preceding flow explained about 90% of the measured variations in drainage velocity. Evaluation of this correlative relationship with the one-dimensional numerical flow model showed that the observed temperature fluctuations could not reproduce the magnitude of variation in the observed drainage velocity. Instead, the model results indicated that flow duration exerts the most control on drainage velocity, with the drainage velocity decreasing nonlinearly with increasing flow duration. These findings suggest flow duration is a primary control of water availability for plant uptake in near surface sediments of an ephemeral stream, an important finding for estimating the ecological risk of natural or engineered changes to streamflow patterns. Correlative analyses of soil moisture data, although easy and widely used, can result in erroneous conclusions of hydrologic cause—effect relationships, and demonstrating the need for joint physically-based numerical modeling and data synthesis for hypothesis testing to support quantitative risk analysis.

  3. Streaming potential during drainage and imbibition

    Zhang, Jiazuo; Vinogradov, Jan; Leinov, Eli; Jackson, M. D.


    The rock pore space in many subsurface settings is saturated with water and one or more immiscible fluid phases. Examples include nonaqueous phase liquids (NAPLs) in contaminated aquifers, supercritical CO2 during sequestration in deep saline aquifers, the vadose zone, and hydrocarbon reservoirs. Self-potential (SP) and seismoelectric (SE) methods have been proposed to monitor multiphase flow in such settings. However, to properly interpret and model these data requires an understanding of the saturation dependence of the streaming potential. This paper presents a methodology to determine the saturation dependence of the streaming potential coupling coefficient (C) and streaming current charge density (Qs) in unsteady state drainage and imbibition experiments and applies the method to published experimental data. Unsteady state experiments do not yield representative values of C and Qs (or other transport properties such as relative permeability and electrical conductivity) at partial saturation (Sw) because Sw within the sample is not uniform. An interpretation method is required to determine the saturation dependence of C and Qs within a representative elementary volume with uniform saturation. The proposed method makes no assumptions about the pore space geometry. Application of the method to published experimental data from two natural sandstone samples shows that C exhibits hysteresis between drainage and imbibition, can exhibit significant nonmonotonic variations with saturation, is nonzero at the irreducible water saturation, and can exceed the value observed at Sw = 1. Moreover, Qs increases with decreasing Sw but is not given by 1/Sw as is often assumed. The variation in Qs with Sw is very similar for a given sample and a given drainage or imbibition process, and the difference between samples is less than the difference between drainage and imbibition. The results presented here can be used to help interpret SP and SE measurements obtained in partially

  4. Drainage area data for Alabama streams

    Stallings, J.S.; Peirce, L.B.


    The drainage area of a river basin is an important parameter in many engineering equations used for hydrologic design. It is not a parameter, however, that always requires precise measurement. Factors in the hydrologic cycle such as rainfall, runoff, transpiration, and infiltration cannot be measured nearly as closely as drainage area. Largely for this reason, drainage areas are often measured to varying degrees of precision depending upon the immediate need, with little thought to some other use or some other user of the figure obtained. It can readily be appreciated that this practice, continued for long by many different agencies, will result in a heterogeneous collection of drainage area figures, often discordant and of an accuracy unknown to any but those who computed them. Figures of drainage area published by various Federal agencies are frequently discrepant or contradictory, giving rise to confusion in the use of drainage area data. Seeking to better this situation, the Federal Inter-Agency River Basin Committee (FIARBC) in November 1951 published its Bulletin No. 4, Inter-Agency Coordination of Drainage Area Data. That Bulletin recommended procedures to be followed by the interested Federal agencies “for coordinating drainage area data in the interest of promoting uniformity, reducing confusion and contradiction of published figures, and improving the ready availability of drainage area data pertaining to drainage basins of the United States and its possessions.”

  5. Streaming patterns in Faraday waves

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


    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...

  6. Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet.

    Smith, Laurence C; Chu, Vena W; Yang, Kang; Gleason, Colin J; Pitcher, Lincoln H; Rennermalm, Asa K; Legleiter, Carl J; Behar, Alberto E; Overstreet, Brandon T; Moustafa, Samiah E; Tedesco, Marco; Forster, Richard R; LeWinter, Adam L; Finnegan, David C; Sheng, Yongwei; Balog, James


    Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the surface drainage system conveyed its own storage volume every meltwater export from the ice sheet to the ocean.

  7. Pattern Matching in Multiple Streams

    Clifford, Raphael; Porat, Ely; Sach, Benjamin


    We investigate the problem of deterministic pattern matching in multiple streams. In this model, one symbol arrives at a time and is associated with one of s streaming texts. The task at each time step is to report if there is a new match between a fixed pattern of length m and a newly updated stream. As is usual in the streaming context, the goal is to use as little space as possible while still reporting matches quickly. We give almost matching upper and lower space bounds for three distinct pattern matching problems. For exact matching we show that the problem can be solved in constant time per arriving symbol and O(m+s) words of space. For the k-mismatch and k-differences problems we give O(k) time solutions that require O(m+ks) words of space. In all three cases we also give space lower bounds which show our methods are optimal up to a single logarithmic factor. Finally we set out a number of open problems related to this new model for pattern matching.

  8. Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet

    Smith, Laurence C.; Chu, Vena W.; Yang, Kang; Gleason, Colin J.; Pitcher, Lincoln H.; Rennermalm, Asa K.; Legleiter, Carl J.; Behar, Alberto E.; Overstreet, Brandon T.; Moustafa, Samiah E.; Tedesco, Marco; Forster, Richard R.; LeWinter, Adam L.; Finnegan, David C.; Sheng, Yongwei; Balog, James


    Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km2 of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54–2.81 cm⋅d−1) indicate that the surface drainage system conveyed its own storage volume every ice watershed for Isortoq, a major proglacial river, totaled ∼41–98% of observed proglacial discharge, highlighting the importance of supraglacial river drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modèle Atmosphérique Régional (MAR) regional climate model (0.056–0.112 km3⋅d−1 vs. ∼0.103 km3⋅d−1), and when integrated over the melt season, totaled just 37–75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean. PMID:25583477

  9. Periphyton communities in New Zealand streams impacted by acid mine drainage

    Bray, J.P.; Broady, P.A.; Niyogi, D.K.; Harding, J.S. [University of Canterbury, Christchurch (New Zealand). School for Biological Science


    Discharges from historic and current coal mines frequently generate waters low in pH (< 3), high in heavy metals ( e. g. Fe, Al) and cover streambeds in metal precipitates. The present study investigated periphyton communities at 52 stream sites on the West Coast, South Island, New Zealand, representing a range of impacts from acid mine drainage (AMD). Taxonomic richness was negatively related to acidity and metal oxides and biomass was negatively correlated with metal oxides, but positively related to acidity. Streams with low pH (< 3.5) had low periphyton richness (14 taxa across all sites) and were dominated by Klebsormidium acidophilum, Navicula cincta and Euglena mutabilis. As pH increased, so did taxonomic richness while community dominance decreased and community composition became more variable. Canonical correspondence analyses of algal assemblages revealed patterns influenced by pH. These findings indicate that streams affected by AMD possess a predictable assemblage composition of algal species that can tolerate the extreme water chemistry and substrate conditions. The predictability of algal communities declines with decreasing stress, as other abiotic and biotic factors become increasingly more important.

  10. Numerical investigation of the spatial scale and time dependency of tile drainage contribution to stream flow

    Thomas, Nicholas W.; Arenas, Antonio A.; Schilling, Keith E.; Weber, Larry J.


    Tile drainage systems are pervasive in the Central U.S., significantly altering the hydrologic system. The purpose of this study was to assess the effects of tile drainage systems on streamflow. A physically based coupled hydrologic model was applied to a 45 km2 agricultural Iowa watershed. Tile drainage was incorporated though an equivalent porous medium approach, calibrated though numerical experimentation. Experimental results indicated that a significant increase in hydraulic conductivity of the equivalent medium layer was needed to achieve agreement in total outflow with an explicit numerical representation of a tiled system. Watershed scale analysis derived the tile drainage contribution to stream flow (QT/Q) from a numerical tracer driven analysis of instream surface water. During precipitation events tile drainage represented 30% of stream flow, whereas during intervals between precipitations events, 61% of stream flow originated from the tile system. A division of event and non-event periods produced strong correlations between QT/Q and drainage area, positive for events, and negative for non-events. The addition of precipitation into the system acted to saturate near surface soils, increase lateral soil water movement, and dilute the relatively stable instream tile flow. Increased intensity precipitation translated the QT/Q relationship downward in a consistent manner. In non-event durations, flat upland areas contributed large contributions of tile flow, diluted by larger groundwater (non-tile) contribution to stream flow in the downstream steeper portion of the watershed. Study results provide new insights on the spatiotemporal response of tile drainage to precipitation and contributions of tile drainage to streamflow at a watershed scale, with results having important implications for nitrate transport.

  11. Quality Assessment in River Network Generalisation by Preserving the Drainage Pattern

    Zhang, L.; Guilbert, E.


    The drainage pattern of a river network is the arrangement in which a stream erodes the channels of its network of tributaries. It can reflect the geographical characteristics of a river network to a certain extent, because it depends on the topography and geology of the land. Whether in cartography or GIS, hydrography is one of the most important feature classes to generalise in order to produce representations at various levels of detail. Cartographic generalisation is an intricate process whereby information is selected and represented on a map at a certain scale, not necessarily preserving all geographical or other cartographic details. There are many methods for river network generalisation, but the generalized results are always inspected by expert cartographers visually. This paper proposes a method that evaluates the quality of a river network generalisation by assessing if drainage patterns are preserved. This method provides a quantitative value that estimates the membership of a river network in different drainage patterns. A set of geometric indicators describing each pattern are presented and the membership of a network is defined based on fuzzy logic. For each pattern, the fuzzy set membership is given by a defined IF-THEN rule composed of several indicators and logical operators. Assessing the quality of a generalisation is done by comparing and analysing the value before and after the network generalisation. This assessment method is tested with several river network generalisation methods on different sets of networks and results are analysed and discussed.

  12. Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

    Ghosh, Suchismita; Moitra, Moumita; Woolverton, Christopher J; Leff, Laura G


    Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis. Also, bacterial abundance and physicochemical data (including metal concentrations) were collected and relationships to bacterial community structure were determined using BIO-ENV analysis. Remediation of the study stream altered environmental conditions, including pH and concentrations of some metals, and consequently, the bacterial community changed. However, remediation did not necessarily restore the stream to conditions found in the unimpacted reference stream; for example, bacterial abundances and concentrations of some elements, such as sulfur, magnesium, and manganese, were different in the remediated stream than in the reference stream. BIO-ENV analysis revealed that changes in pH and iron concentration, associated with remediation, primarily explained temporal alterations in bacterial community structure. Although the sites sampled in the remediated stream were in relatively close proximity to each other, spatial variation in community composition suggests that differences in local environmental conditions may have large impacts on the microbial assemblage.

  13. The burial of headwater streams in drainage pipes reduces in-stream nitrate retention: results from two US metropolitan areas

    Beaulieu, J. J.; Mayer, P. M.; Kaushal, S.; Pennino, M. J.; Arango, C. P.; Balz, D. A.; Fritz, K. M.; Golden, H. E.; Knightes, C. D.


    Nitrogen (N) retention in stream networks is an important ecosystem service that may be affected by the widespread burial of headwater streams in urban watersheds. Stream burial occurs when segments of a channel are encased in drainage pipe and buried beneath the land surface to facilitate above ground development or stormwater runoff. We predicted that burial suppresses the capacity of streams to retain and transform nitrate, the dominate form of bioavailable N in urban streams, by eliminating primary production, reducing respiration rates, and decreasing water residence time. We tested these predictions by measuring whole-stream nitrate (NO3-) removal rates using 15NO3- isotope tracer releases in reaches that were buried and open to the sunlight in three streams in Cincinnati, Ohio and three streams in Baltimore, Maryland during four seasons. Nitrate uptake lengths in buried reaches (range: 560 - 43,650 m) were 2-98 times greater than open reaches exposed to daylight (range: 85 - 7195 m), indicating that buried reaches were substantially less effective at retaining NO3- than open reaches. Nitrate retention in buried reaches was suppressed by a combination of hydrological and biological processes. High water velocities in buried reaches (buried= 5.8 m/s, open=1.48 m/s) rapidly exported NO3- from the channel, reducing the potential for in-stream NO3- retention. Uptake lengths in the buried reaches were lengthened further by low in-stream biological NO3- demand, as indicated by NO3- uptake velocities 16-fold lower than that of the open reaches. Similarly, buried reaches had lower ecosystem respiration rates than open reaches (buried=1.5g O2/m2/hr, open=4.5g O2/m2/hr), likely due to lower organic matter standing stocks (buried=12 gAFMD/m2, open=48 gAFDM/m2). Biological activity in the buried reaches was further suppressed by the absence of light which precluded photosynthetic activity and the associated assimilative N demand. Overall, our results demonstrate that the

  14. Drainage Basins Used for Assessing Trends in Concentration of Pesticides in Streams of the United States, 1992-2010

    U.S. Geological Survey, Department of the Interior — This dataset consists of drainage basin boundaries for 212 U.S. Geological Survey (USGS) stream sites sampled in the National Water-Quality Assessment (NAWQA)...

  15. Acid mine drainage and stream recovery: Effects of restoration on water quality, macroinvertebrates, and fish

    Williams K.M.


    Full Text Available Acid mine drainage (AMD is a prominent threat to water quality in many of the world’s mining districts as it can severely degrade both the biological community and physical habitat of receiving streams. There are relatively few long-term studies investigating the ability of stream ecosystems to recover from AMD. Here we assess watershed scale recovery of a cold-water stream from pollution by AMD using a 1967 survey of the biological and chemical properties of the stream as a pre-restoration benchmark. We sampled water chemistry, benthic macroinvertebrates, and fish throughout the watershed during the spring and summer of 2011. Water chemistry results indicated that pH and total alkalinity increased post-restoration, while acidity, sulfate, and iron concentrations decreased. Watershed-level taxa richness, local taxa richness, biomass, diversity, and density of macroinvertebrates were significantly higher post-restoration; however, %EPT was not significantly different. Fish species richness, density, and brook trout density were all significantly higher post-restoration. These results provide clear evidence that both abiotic and biotic components of streams can recover from AMD pollution.

  16. Vascular riffle flora of Appalachian streams: the ecology and effects of acid mine drainage on Justificia americana (L. ) Vahl

    Koryak, M.; Reilly, R.J.


    Justicia americana is a stout-based colonial plant, abundant in most of the larger, low to moderate gradient streams of the upper Ohio River basin. The distribution of J. americana is related to acid drainage from bituminous coal mining operations in the upper Ohio River drainage basin. Possible fluvial and biological consequences of the colonization or absence of Justicia are considered. Luxuriant growths were noted on gravel bars and riffles of larger, unpolluted streams in the basin. Acid mine drainage severely depresses the growth of the plant, leaving gravel shoals and riffles in the acid streams either barren or dominated by other emergent species. Particular among these new species is Elecocharis acicularis. The elimination of J. americana from suitable habitat adversely affects channel morphology, substrate composition, general aesthetic quality and aquatic stream life in the region. 16 references, 2 figures, 3 tables.

  17. A 1-D modelling of streaming potential dependence on water content during drainage experiment in sand

    Allègre, Vincent; Ackerer, Philippe; Jouniaux, Laurence; Sailhac, Pascal; 10.1111/j.1365-246X.2012.05371.x


    The understanding of electrokinetics for unsaturated conditions is crucial for numerous of geophysical data interpretation. Nevertheless, the behaviour of the streaming potential coefficient C as a function of the water saturation Sw is still discussed. We propose here to model both the Richards' equation for hydrodynamics and the Poisson's equation for electrical potential for unsaturated conditions using 1-D finite element method. The equations are first presented and the numerical scheme is then detailed for the Poisson's equation. Then, computed streaming potentials (SPs) are compared to recently published SP measurements carried out during drainage experiment in a sand column. We show that the apparent measurement of DV / DP for the dipoles can provide the SP coefficient in these conditions. Two tests have been performed using existing models for the SP coefficient and a third one using a new relation. The results show that existing models of unsaturated SP coefficients C(Sw) provide poor results in term...

  18. Watershed Hydrologic Response and Drainage Network Topology Across a Spectrum of Urban Development Patterns

    Miller, A. J.; Lindner, G. A.; Shamer, S. Z.; Schmidt, K. M.; Kather, M. J.; Jones, D.; Baker, M. E.; Welty, C.


    The Gwynns Falls is the primary study watershed of the Baltimore Ecosystem Study LTER and is the site of a nested set of 15 current and formerly active stream gages at drainage areas ranging from parks; to 1950's-60's inner-ring suburbs with >40% impervious area, buried headwater tributaries, channelized streams and no stormwater management; to 1990's-2000's suburban development with forested riparian zones, limited impervious area and extensive stormwater management. Spatial data sets used to characterize these watersheds include aerial photography and LiDAR topography at ~1 m horizontal resolution, as well as surface hydrography, land cover, buildings, roads, storm drains, stormwater management facilities, soil types, and bedrock geology. Hydrologic analysis, including storm-period mass balance, is supported by the availability of a HydroNEXRAD gridded precipitation data set with 1 km2 spatial and 15-minute temporal resolution covering the period from 2000-2011, as well as a set of 8 pairs of tipping-bucket rain gages. The goal of this study is to compare watershed storm response across the spectrum of development ages and patterns. In order to assess characteristic response signatures we have developed a library of quickflow hydrographs, and we have extracted unit hydrographs for short-duration rainfall pulses and for simple storms of longer duration that activate a larger fraction of the available contributing area. We present analyses of hydrograph shape and precipitation-runoff mass balance. Potential controls include watershed size and shape, impervious cover, natural and artificial drainage density, dominant soil types, spatial distribution of saturated surfaces, and percent of drainage area controlled by stormwater management. We employ simplifying assumptions to investigate the extent to which comparative patterns of storm response can be explained by the topology of the augmented urban drainage network before invoking other controlling factors. In order

  19. The effects of drainage on groundwater quality and plant species distribution in stream valley meadows

    Grootjans, A.P.; Diggelen, R. van; Wassen, M.J.; Wiersinga, W.A.


    Conditions in fen meadows in Dutch stream valleys are influenced by both deep (Ca2+-rich) and shallow (Ca2+-poor) groundwater flows. The distribution patterns of phreatophytic (groundwater-influenced) plant species showed distinct relationships with the distribution of different groundwater types.

  20. Origin and influence of coal mine drainage on streams of the United States

    Powell, J.D.


    Degradation of water quality related to oxidation of iron disulfide minerals associated with coal is a naturally occurring process that has been observed since the late seventeenth century, many years before commencement of commercial coal mining in the United States. Disturbing coal strata during mining operations accelerates this natural deterioration of water quality by exposing greater surface areas of reactive minerals to the weathering effects of the atmosphere, hydrosphere, and biosphere. Degraded water quality in the temperate eastern half of the United States is readily detected because of the low mineralization of natural water. Maps are presented showing areas in the eastern United States where concentrations of chemical constituents in water affected by coal mining (pH, dissolved sulfate, total iron, total manganese) exceed background values and indicate effects of coal mining. Areas in the East most affected by mine drainage are in western Pennsylvania, southern Ohio, western Maryland, West Virginia, southern Illinois, western Kentucky, northern Missouri, and southern Iowa. Effects of coal mining on water quality in the more arid western half of the United States are more difficult to detect because of the high degree of mineralization of natural water. Normal background concentrations of constituents are not useful in evaluating effects of coal mine drainage on streams in the more arid West. Three approaches to reduce the effects of coal mining on water quality are: (1) exclusion of oxygenated water from reactive minerals, (2) neutralization of the acid produced, (3) retardation of acid-producing bacteria population in spoil material, by application of detergents that do not produce byproducts requiring disposal. These approaches can be used to help prevent further degradation of water quality in streams by future mining. ?? 1988 Springer-Verlag New York Inc.

  1. A statistical test for drainage network recognition using MeanStreamDrop analysis

    Corrado Cencetti


    Full Text Available This paper provides a new statistical test to evaluate the threshold of validity for the Mean Stream Drop analysis. In the case of a constant area threshold, the method aims to provide a unique threshold value to extract the drainage network through a statistical test more efficient than those widely used. The proposal starts from the assumption that a minimum threshold value exists suitable for drainage network extraction. Then, the method proceeds with Horton–Strahler ordering of the network and statistically analysing the network geometry. This procedure is repeated for all the threshold values in the set under investigation, using a statistical permutation test, called APTDTM (Adjusted Permutation Test based on the Difference between Trimmed Means. Statistical significance is evaluated by p-values adjusted to account for multiple comparisons. As a final result of the statistical analysis, the right threshold value for the specific basin is identified. Classical procedures are based on a set of two sample t-tests. However, this method relies on the assumptions of normality and homogeneity of variance, which are unlikely to hold in practice. The APTDTM test presented here provides accurate p-values even when the sampling distribution is not close to normal, or there is heteroskedasticity in the data.

  2. Roles of Benthic Algae in the Structure, Function, and Assessment of Stream Ecosystems Affected by Acid Mine Drainage

    Tens of thousands of stream kilometers around the world are degraded by a legacy of environmental impacts and acid mine drainage (AMD) caused by abandoned underground and surface mines, piles of discarded coal wastes, and tailings. Increased acidity, high concentrations of metals...

  3. Roles of Benthic Algae in the Structure, Function, and Assessment of Stream Ecosystems Affected by Acid Mine Drainage

    Tens of thousands of stream kilometers around the world are degraded by a legacy of environmental impacts and acid mine drainage (AMD) caused by abandoned underground and surface mines, piles of discarded coal wastes, and tailings. Increased acidity, high concentrations of metals...

  4. Numerical comparison of coal spontaneous combustion danger influenced by different methane drainage patterns in gob area

    ZHU Hong-qing; LIU Xing-kui; ZHANG Ru-ming; ZHANG Sheng-zhu


    The influence of gas drainage on float coal spontaneous combustion in the work face with "U" style ventilation was studied. Numerical simulation was used to compare the mutative law of steady flow and density field in the gob area under different drainage conditions by solving the equation set, including mass, momentum, and component transition. Consequently, the sequence of drainage effect and safety was obtained. The result manifests that the more effective the drainage pattern is, the easier float coal spontaneous combustion is caused due to air being guided into the depth of the gob area when the drainage position is arranged in the gas accumulation area. If the widened scope of oxidation zone exceeds the upper limit of the work face advancing speed, nitrogen injection should be applied to decrease the probability of spontaneous combustion. Then, the pipe laying drainage in the upper angle is most economical and safe compared with other drainage patterns when only the situation of gas accumulation is controlled in the upper angle. Finally, drainage pressure must not be too great. Otherwise the drainage density will decrease even if hazard is caused by back flow possibly happening in the return outlet when the drainage position is arranged near the work face.

  5. Pattern Discovery and Change Detection of Online Music Query Streams

    Li, Hua-Fu

    In this paper, an efficient stream mining algorithm, called FTP-stream (Frequent Temporal Pattern mining of streams), is proposed to find the frequent temporal patterns over melody sequence streams. In the framework of our proposed algorithm, an effective bit-sequence representation is used to reduce the time and memory needed to slide the windows. The FTP-stream algorithm can calculate the support threshold in only a single pass based on the concept of bit-sequence representation. It takes the advantage of "left" and "and" operations of the representation. Experiments show that the proposed algorithm only scans the music query stream once, and runs significant faster and consumes less memory than existing algorithms, such as SWFI-stream and Moment.

  6. PGG: An Online Pattern Based Approach for Stream Variation Management

    Lu-An Tang; Bin Cui; Hong-Yan Li; Gao-Shan Miao; Dong-Qing Yang; Xin-Biao Zhou


    Many database applications require efficient processing of data streams with value variations and fiuctuant sampling frequency. The variations typically imply fundamental features of the stream and important domain knowledge of underlying objects. In some data streams, successive events seem to recur in a certain time interval, but the data indeed evolves with tiny differences as time elapses. This feature, so called pseudo periodicity, poses a new challenge to stream variation management. This study focuses on the online management for variations over such streams. The idea can be applied to many scenarios such as patient vital signal monitoring in medical applications. This paper proposes a new method named Pattern Growth Graph (PGG) to detect and manage variations over evolving streams with following features: 1) adopts the wave-pattern to capture the major information of data evolution and represent them compactly;2) detects the variations in a single pass over the stream with the help of wave-pattern matching algorithm; 3) only stores different segments of the pattern for incoming stream, and hence substantially compresses the data without losing important information; 4) distinguishes meaningful data changes from noise and reconstructs the stream with acceptable accuracy.Extensive experiments on real datasets containing millions of data items, as well as a prototype system, are carried out to demonstrate the feasibility and effectiveness of the proposed scheme.

  7. Evaluating remedial alternatives for an acid mine drainage stream: Application of a reactive transport model

    Runkel, R.L.; Kimball, B.A.


    A reactive transport model based on one-dimensional transport and equilibrium chemistry is applied to synoptic data from an acid mine drainage stream. Model inputs include streamflow estimates based on tracer dilution, inflow chemistry based on synoptic sampling, and equilibrium constants describing acid/base, complexation, precipitation/dissolution, and sorption reactions. The dominant features of observed spatial profiles in pH and metal concentration are reproduced along the 3.5-km study reach by simulating the precipitation of Fe(III) and Al solid phases and the sorption of Cu, As, and Pb onto freshly precipitated iron-(III) oxides. Given this quantitative description of existing conditions, additional simulations are conducted to estimate the streamwater quality that could result from two hypothetical remediation plans. Both remediation plans involve the addition of CaCO3 to raise the pH of a small, acidic inflow from ???2.4 to ???7.0. This pH increase results in a reduced metal load that is routed downstream by the reactive transport model, thereby providing an estimate of post-remediation water quality. The first remediation plan assumes a closed system wherein inflow Fe(II) is not oxidized by the treatment system; under the second remediation plan, an open system is assumed, and Fe(II) is oxidized within the treatment system. Both plans increase instream pH and substantially reduce total and dissolved concentrations of Al, As, Cu, and Fe(II+III) at the terminus of the study reach. Dissolved Pb concentrations are reduced by ???18% under the first remediation plan due to sorption onto iron-(III) oxides within the treatment system and stream channel. In contrast, iron(III) oxides are limiting under the second remediation plan, and removal of dissolved Pb occurs primarily within the treatment system. This limitation results in an increase in dissolved Pb concentrations over existing conditions as additional downstream sources of Pb are not attenuated by

  8. Preservation procedures for arsenic speciation in a stream affected by acid mine drainage in southwestern Spain.

    Sánchez-Rodas, Daniel; Oliveira, Vanesa; Sarmiento, Aguasanta M; Gómez-Ariza, José Luis; Nieto, José Miguel


    A preservation study has been performed for arsenic speciation in surface freshwaters affected by acid mine drainage (AMD), a pollution source characterized by low pH and high metallic content. Two sample preservation procedures described in the literature were attempted using opaque glass containers and refrigeration: i) addition of 0.25 mol L(-1) EDTA to the samples, which maintained the stability of the arsenic species for 3 h; and ii) in situ sample clean-up with a cationic exchange resin, in order to reduce the metallic load, which resulted in a partial co-adsorption of arsenic onto Fe precipitates. A new proposed method was also tried: sample acidification with 6 mol L(-1) HCl followed by in situ clean-up with a cationic exchange resin, which allowed a longer preservation time of at least 48 h. The proposed method was successfully applied to water samples with high arsenic content, taken from the Aguas Agrias Stream (Odiel River Basin, SW Spain), which is severely affected by AMD that originates at the nearby polymetallic sulfide mine of Tharsis. The speciation results obtained by liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) indicated that during the summer the main arsenic species was As(V) at the hundred microg L(-1) level, followed by DMA (dimethyl arsenic) and As(III) below the ten microg L(-1) level. In winter, As(V) and As(III) increased at least fivefold, whereas the DMA was not detected.

  9. Influences of water and substrate quality for periphyton in a montane stream affected by acid mine drainage

    Niyogi, Dev K.; McKnight, Diane M.; Lewis, William M.


    St. Kevin Gulch, a headwater stream of the Rocky Mountains of Colorado, receives acid mine drainage that maintains low pH, high concentrations of heavy metals, and high rates of metal hydroxide deposition. An acid-tolerant alga, Ulothrix sp., is present below the source of mine drainage in St. Kevin Gulch, but its biomass is limited by the deposition rates of iron hydroxides, which are especially high near the source. An experimental diversion of the mine drainage increased the quality of water and improved the substrate condition through a reduction of deposition rates. During the first year of the experiment,Ulothrix ecame abundant in this reach. During the second year, pH increased to the point at which aluminum hydroxides precipitated from the stream water onto the streambed; this change inhibited the growth of all periphyton, includingUlothrixThe deposition rate of aluminum hydroxides, however, was less than that of iron hydroxides in stream reaches with high Ulothrix biomas uggesting that metal hydroxides vary by type in their effect on periphyton.

  10. Geochemistry of acid mine drainage from a coal mining area and processes controlling metal attenuation in stream waters, southern Brazil



    Full Text Available Acid drainage influence on the water and sediment quality was investigated in a coal mining area (southern Brazil. Mine drainage showed pH between 3.2 and 4.6 and elevated concentrations of sulfate, As and metals, of which, Fe, Mn and Zn exceeded the limits for the emission of effluents stated in the Brazilian legislation. Arsenic also exceeded the limit, but only slightly. Groundwater monitoring wells from active mines and tailings piles showed pH interval and chemical concentrations similar to those of mine drainage. However, the river and ground water samples of municipal public water supplies revealed a pH range from 7.2 to 7.5 and low chemical concentrations, although Cd concentration slightly exceeded the limit adopted by Brazilian legislation for groundwater. In general, surface waters showed large pH range (6 to 10.8, and changes caused by acid drainage in the chemical composition of these waters were not very significant. Locally, acid drainage seemed to have dissolved carbonate rocks present in the local stratigraphic sequence, attenuating the dispersion of metals and As. Stream sediments presented anomalies of these elements, which were strongly dependent on the proximity of tailings piles and abandoned mines. We found that precipitation processes in sediments and the dilution of dissolved phases were responsible for the attenuation of the concentrations of the metals and As in the acid drainage and river water mixing zone. In general, a larger influence of mining activities on the chemical composition of the surface waters and sediments was observed when enrichment factors in relation to regional background levels were used.

  11. Sources of alkalinity and acidity along an acid mine drainage remediated stream in SE Ohio: Hewett Fork

    Schleich, K. L.; Lopez, D. A.; Bowman, J. R.; Kruse, N. A.; Mackey, A. L.; VanDervort, D.; Korenowsky, R.


    In the remediation of acid mine drainage impacted streams, it is important to locate and quantify the sources of acidity and alkalinity inputs. These parameters affect the long-term recovery of the stream habitat. Previous studies have focused on treating the remediation of AMD as point source pollution, targeting the main acid seep for remediation. However, in the interest of biological and chemical recovery, it is important to understand how sources of alkalinity and acidity, throughout the stream, affect water and sediment quality. The Hewett Fork watershed in Southeastern Ohio is impacted by AMD from the AS-14 mine complex in Carbondale, Ohio. In attempts to remediate the stream, the water is being treated with a continuous alkaline input from a calcium oxide doser. While the section of watershed furthest downstream from the doser is showing signs of recovery, the water chemistry and aquatic life near the doser are still impacted. The objective of this study is to examine and model the chemistry of the tributaries of Hewett Fork to see how they contribute to the alkalinity and acidity budgets of the main stem of the stream. By examining the inputs of tributaries into the main stem, this project aims to understand processes occurring during remediation throughout the entire stream. Discharge was measured during a dry period in October, 2012 and at a high flow in May, 2013. Field parameters such as pH, TDS, DO, alkalinity and acidity were also determined. Low flow data collected during fall sampling shows variable flow along the stream path, the stream gains water from ground water at some points while it loses water at others, potentially due to variable elevation of the water table. Flow data collected during spring sampling shows that Hewett Fork is a gaining stream during that period with inputs from groundwater contributing to increasing flow downstream. When using this data to calculate the net alkalinity load along the stream, there are areas with alkaline

  12. Spatio-temporal changes of lymphatic contractility and drainage patterns following lymphadenectomy in mice.

    Sunkuk Kwon

    Full Text Available OBJECTIVE: To investigate the redirection of lymphatic drainage post-lymphadenectomy using non-invasive near-infrared fluorescence (NIRF imaging, and to subsequently assess impact on metastasis. BACKGROUND: Cancer-acquired lymphedema arises from dysfunctional fluid transport after lymphadenectomy performed for staging and to disrupt drainage pathways for regional control of disease. However, little is known about the normal regenerative processes of the lymphatics in response to lymphadenectomy and how these responses can be accelerated, delayed, or can impact metastasis. METHODS: Changes in lymphatic "pumping" function and drainage patterns were non-invasively and longitudinally imaged using NIRF lymphatic imaging after popliteal lymphadenectomy in mice. In a cohort of mice, B16F10 melanoma was inoculated on the dorsal aspect of the paw 27 days after lymphadenectomy to assess how drainage patterns affect metastasis. RESULTS: NIRF imaging demonstrates that, although lymphatic function and drainage patterns change significantly in early response to popliteal lymph node (PLN removal in mice, these changes are transient and regress dramatically due to a high regenerative capacity of the lymphatics and co-opting of collateral lymphatic pathways around the site of obstruction. Metastases followed the pattern of collateral pathways and could be detected proximal to the site of lymphadenectomy. CONCLUSIONS: Both lymphatic vessel regeneration and co-opting of contralateral vessels occur following lymphadenectomy, with contractile function restored within 13 days, providing a basis for preclinical and clinical investigations to hasten lymphatic repair and restore contractile lymphatic function after surgery to prevent cancer-acquired lymphedema. Patterns of cancer metastasis after lymphadenectomy were altered, consistent with patterns of re-directed lymphatic drainage.

  13. Classification of Thermal Patterns at Karst Springs and Cave Streams

    Luhmann, A.J.; Covington, M.D.; Peters, Albert J.; Alexander, S.C.; Anger, C.T.; Green, J.A.; Runkel, Anthony C.; Alexander, E.C.


    Thermal patterns of karst springs and cave streams provide potentially useful information concerning aquifer geometry and recharge. Temperature monitoring at 25 springs and cave streams in southeastern Minnesota has shown four distinct thermal patterns. These patterns can be divided into two types: those produced by flow paths with ineffective heat exchange, such as conduits, and those produced by flow paths with effective heat exchange, such as small fractures and pore space. Thermally ineffective patterns result when water flows through the aquifer before it can equilibrate to the rock temperature. Thermally ineffective patterns can be either event-scale, as produced by rainfall or snowmelt events, or seasonal scale, as produced by input from a perennial surface stream. Thermally effective patterns result when water equilibrates to rock temperature, and the patterns displayed depend on whether the aquifer temperature is changing over time. Shallow aquifers with seasonally varying temperatures display a phase-shifted seasonal signal, whereas deeper aquifers with constant temperatures display a stable temperature pattern. An individual aquifer may display more than one of these patterns. Since karst aquifers typically contain both thermally effective and ineffective routes, we argue that the thermal response is strongly influenced by recharge mode. ?? 2010 The Author(s). Journal compilation ?? 2010 National Ground Water Association.

  14. Classification of thermal patterns at karst springs and cave streams.

    Luhmann, Andrew J; Covington, Matthew D; Peters, Andrew J; Alexander, Scott C; Anger, Cale T; Green, Jeffrey A; Runkel, Anthony C; Alexander, E Calvin


    Thermal patterns of karst springs and cave streams provide potentially useful information concerning aquifer geometry and recharge. Temperature monitoring at 25 springs and cave streams in southeastern Minnesota has shown four distinct thermal patterns. These patterns can be divided into two types: those produced by flow paths with ineffective heat exchange, such as conduits, and those produced by flow paths with effective heat exchange, such as small fractures and pore space. Thermally ineffective patterns result when water flows through the aquifer before it can equilibrate to the rock temperature. Thermally ineffective patterns can be either event-scale, as produced by rainfall or snowmelt events, or seasonal scale, as produced by input from a perennial surface stream. Thermally effective patterns result when water equilibrates to rock temperature, and the patterns displayed depend on whether the aquifer temperature is changing over time. Shallow aquifers with seasonally varying temperatures display a phase-shifted seasonal signal, whereas deeper aquifers with constant temperatures display a stable temperature pattern. An individual aquifer may display more than one of these patterns. Since karst aquifers typically contain both thermally effective and ineffective routes, we argue that the thermal response is strongly influenced by recharge mode.

  15. Climate change and increased zinc concentrations in a Rocky Mountain acid rock drainage stream

    Crouch, C. M.; Todd, A. S.; McKnight, D. M.


    The Snake River Watershed in Colorado is impacted by acid rock drainage (ARD) originating from both natural sources and sources associated with the historic mining in the watershed. Downstream of mines, the high metal ion concentrations, low pH, and metal oxide deposition cause contamination which disrupts ecosystem functions, impairs biological diversity, and contaminates surface and groundwater drinking supplies. One obvious measure of the severity of this contamination is that the self-sustaining trout populations in the watershed are quite sparse. While elevated concentrations of numerous trace metals are present, dissolved zinc is used as an indicator of trout habitat water quality because the fish are so impacted by its presence. Water quality was monitored along the Snake River from 1980 to 1990 and since then less frequent sampling was conducted as part of research studies and efforts to designate portions of the watershed for mitigation. Metals concentrations during the seasonal low flows of September and October have been observed to increase significantly over that time. In particular, at a site in the headwaters well above the historic mining impacts, zinc concentrations, which were measured between 0.3 and 0.4 mg/L through the 1980s, have now exceeded 1.2 mg/L in the past several years. This four-fold increase in zinc concentrations is associated with an increase in sulfate concentrations, which indicates that these water quality changes are driven primarily by accelerated natural weathering of pyrite in the watershed. The observed increase in natural ARD - possibly the result of climate change - may have implications for mitigation. Currently, these trends are being evaluated by reanalyzing the archived samples to delineate the spatial and temporal changes in contamination. Processes which may be driving the accelerated natural weathering include the earlier occurrence of peak snowmelt due to climate change which causes lower stream flows and drier

  16. Power-law scaling in daily rainfall patterns and consequences in urban stream discharges

    Park, Jeryang; Krueger, Elisabeth H.; Kim, Dongkyun; Rao, Suresh C.


    Poissonian rainfall has been frequently used for modelling stream discharge in a catchment at the daily scale. Generally, it is assumed that the daily rainfall depth is described by memoryless exponential distribution which is transformed to stream discharge, resulting in an analytical pdf for discharge [Gamma distribution]. While it is true that catchment hydrological filtering processes (censored by constant rate ET losses, and first-order recession) increases "memory", reflected in 1/f noise in discharge time series. Here, we show that for urban watersheds in South Korea: (1) the observation of daily rainfall depths follow power-law pdfs, and spectral slopes range between 0.2 ~ 0.4; and (2) the stream discharge pdfs have power-law tails. These observation results suggest that multiple hydro-climatic factors (e.g., non-stationarity of rainfall patterns) and hydrologic filtering (increasing impervious area; more complex urban drainage networks) influence the catchment hydrologic responses. We test the role of such factors using a parsimonious model, using different types of daily rainfall patterns (e.g., power-law distributed rainfall depth with Poisson distribution in its frequency) and urban settings to reproduce patterns similar to those observed in empirical records. Our results indicate that fractality in temporally up-scaled rainfall, and the consequences of large extreme events are preserved as high discharge events in urbanizing catchments. Implications of these results to modeling urban hydrologic responses and impacts on receiving waters are discussed.

  17. A geostatistical approach for describing spatial pattern in stream networks

    Ganio, L.M.; Torgersen, C.E.; Gresswell, R.E.


    The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other hand, data collected in the network may be spatially autocorrelated and thus not suitable for traditional statistical analyses. Here we provide a method that uses commercially available software to construct an empirical variogram to describe spatial pattern in the relative abundance of coastal cutthroat trout in headwater stream networks. We describe the mathematical and practical considerations involved in calculating a variogram using a non-Euclidean distance metric to incorporate the network pathway structure in the analysis of spatial variability, and use a non-parametric technique to ascertain if the pattern in the empirical variogram is non-random.

  18. Describing spatial pattern in stream networks: A practical approach

    Ganio, L.M.; Torgersen, C.E.; Gresswell, R.E.


    The shape and configuration of branched networks influence ecological patterns and processes. Recent investigations of network influences in riverine ecology stress the need to quantify spatial structure not only in a two-dimensional plane, but also in networks. An initial step in understanding data from stream networks is discerning non-random patterns along the network. On the other hand, data collected in the network may be spatially autocorrelated and thus not suitable for traditional statistical analyses. Here we provide a method that uses commercially available software to construct an empirical variogram to describe spatial pattern in the relative abundance of coastal cutthroat trout in headwater stream networks. We describe the mathematical and practical considerations involved in calculating a variogram using a non-Euclidean distance metric to incorporate the network pathway structure in the analysis of spatial variability, and use a non-parametric technique to ascertain if the pattern in the empirical variogram is non-random.

  19. Ribbed bedforms on palaeo-ice stream beds resemble regular patterns of basal shear stress ('traction ribs') inferred from modern ice streams

    Stokes, Chris R.; Margold, Martin; Creyts, Timothy


    Rapidly-flowing ice streams are an important mechanism through which ice sheets lose mass, and much work has focussed on elucidating the processes that increase or decrease their velocity. Recent work using standard inverse methods has inferred previously-unrecognised regular patterns of high basal shear stress ('sticky spots' >200 kPa) beneath a number of ice streams in Antarctica and Greenland, termed 'traction ribs'. They appear at a scale intermediate between smaller ribbed moraines and much larger mega-ribs observed on palaeo-ice sheet beds, but it is unclear whether they have a topographic expression at the bed. Here, we report observations of rib-like bedforms from Digital Elevation Models (DEMs) along palaeo-ice stream beds in western Canada that resemble both the pattern and dimensions of traction ribs. Their identification suggests that traction ribs may have a topographic expression that lies between, and partly overlaps with, ribbed moraines and much larger mega-ribs. These intermediate-sized bedforms support the notion of a ribbed bedform continuum. Their formation remains conjectural, but our observations from palaeo-ice streams, coupled with those from modern ice masses, suggest they are consistent with wave-like instabilities occurring in the coupled flow of ice and till and modulated by subglacial meltwater drainage. Their form and pattern may also involve glaciotectonism of subglacial sediments.

  20. Benthic Communities of Low-Order Streams Affected by Acid Mine Drainages: A Case Study from Central Europe

    Marek Svitok


    Full Text Available Only little attention has been paid to the impact of acid mine drainages (AMD on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská Štiavnica mining region (Slovakia. The studied streams showed typical signs of mine drainage pollution: higher conductivity, elevated iron, aluminum, zinc and copper loads and accumulations of ferric precipitates. Electric conductivity correlated strongly with most of the investigated elements (weighted mean absolute correlation = 0.95 and, therefore, can be recommended as a good proxy indicator for rapid AMD pollution assessments. The diversity and composition of invertebrate assemblages was related to water chemistry. Taxa richness decreased significantly along an AMD-intensity gradient. While moderately affected sites supported relatively rich assemblages, the harshest environmental conditions (pH < 2.5 were typical for the presence of a limited number of very tolerant taxa, such as Oligochaeta and some Diptera (Limnophyes, Forcipomyiinae. The trophic guild structure correlated significantly with AMD chemistry, whereby predators completely disappeared under the most severe AMD conditions. We also provide a brief review of the AMD literature and outline the needs for future detailed studies involving functional descriptors of the impact of AMD on aquatic ecosystems.

  1. Mineralogy and geochemistry of trace metals and REE in volcanic massive sulfide host rocks, stream sediments, stream waters and acid mine drainage from the Lousal mine area (Iberian Pyrite Belt, Portugal)

    Ferreira da Silva, E. [GeoBioTec - GeoBiosciences, Technologies and Engineering Research Center, Departamento de Geociencias, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)], E-mail:; Bobos, I. [Departamento de Geologia, Faculdade de Ciencias da Universidade do Porto, Rua Campo Alegre 687 4169-007 Porto (Portugal); Xavier Matos, J. [Centro de Estudos Geologicos e Mineiros de Beja, Rua Frei Amador Arrais No. 39 r/c, Apartado 104, 7801-902 Beja (Portugal); Patinha, C.; Reis, A.P.; Cardoso Fonseca, E. [GeoBioTec - GeoBiosciences, Technologies and Engineering Research Center, Departamento de Geociencias, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)


    Acid mine drainage represents a major source of water pollution in the Lousal area. The concentrations of trace metals and the rare earth elements (REE) in the host rocks, stream sediment, surface waters and acid mine drainage (AMD) associated with abandoned mine adits and tailings impoundments were determined, in order to fingerprint their sources and to understand their mobility and water-rock interaction. The results show that the Fe-SO{sub 4}-rich acid waters vary substantially in composition both spatially and seasonally. These waters include very low pH (mostly in the range 1.9-3.0), extreme SO{sub 4} concentrations (4635-20,070 mg L{sup -1}SO{sub 4}{sup 2-}), high metal contents (Fe, Al, Cu, Zn and Mn) and very high REE contents. The trace metal concentrations decrease downstream from the discharge points either due to precipitation of neoformed phases or to dilution. The North-American shale composite (NASC)-normalized patterns corresponding to sediment from one stream (Corona stream) show a flat tendency or are slightly enriched in light-REE (LREE). The NASC-normalized patterns corresponding to acidic mine waters show enrichment in the middle REE (MREE) with respect to the LREE and heavy REE (HREE). Moreover, the REE concentrations in acidic mine waters are 2 or 3 orders of magnitude higher than those of the surface waters. Changes of REE concentrations and variation of Eu anomaly show two spatially distinct patterns: (a) pond and spring waters with higher REE concentrations (ranging from 375 to 2870 {mu}g L{sup -1}), that records conspicuous negative Eu anomaly, and (b) seeps from tailings impoundments corresponding to lower REE concentrations than the first pattern (ranging from 350 to 1139 {mu}g L{sup -1}) with typically negative Eu anomaly. The stream water samples collected from the impacted stream during the spring show a low pH (2.8-3.1) and contain high concentrations of Fe and trace elements (up to 61 mg L{sup -1}). Also, temporal variations of

  2. Investigation of acoustic streaming patterns around oscillating sharp edges

    Nama, Nitesh; Huang, Tony Jun; Costanzo, Francesco


    Oscillating sharp edges have been employed to achieve rapid and homogeneous mixing in microchannels using acoustic streaming. Here we use a perturbation approach to study the flow around oscillating sharp edges in a microchannel. This work extends prior experimental studies to numerically characterize the effect of various parameters on the acoustically induced flow. Our numerical results match well with the experimental results. We investigated multiple device parameters such as the tip angle, oscillation amplitude, and channel dimensions. Our results indicate that, due to the inherent nonlinearity of acoustic streaming, the channel dimensions could significantly impact the flow patterns and device performance.

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

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


    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.

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

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


    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.

  5. Benthic invertebrates of benchmark streams in agricultural areas of eastern Wisconsin, Western Lake Michigan Drainages

    Rheaume, S.J.; Lenz, B.N.; Scudder, B.C.


    This study describes the benthic invertebrate communities of 20 benchmark streams in agricultural areas of eastern Wisconsin. Streams with minimal adverse effects from human activity were selected from four agricultural areas with differing surficial deposits and bedrock types (relatively homogeneous units, or RHU's). Most aquatic invertebrate orders were well represented in the 20 benchmark stream samples; 217 species and 151 genera within 56 families were identified. Diptera was the best represented order (96 species), followed by Trichoptera (42 species) and Ephemeroptera (26 species). Diptera were the most abundant organisms in terms of numbers of individuals in the sample (28 percent of the total) followed by Trichoptera (25 percent) and Ephemeroptera (13 percent). Nine species of freshwater mussels were found, but only in 5 of the 20 benchmark streams.

  6. pH dependence of iron photoreduction in a rocky mountain stream affected by acid mine drainage

    McKnight, Diane M.; Kimball, B.A.; Runkel, R.L.


    The redox speciation of dissolved iron and the transport of iron in acidic, metal-enriched streams is controlled by precipitation and dissolution of iron hydroxides, by photoreduction of dissolved ferric iron and hydrous iron oxides, and by oxidation of the resulting dissolved ferrous iron. We examined the pH dependence of these processes in an acidic mine-drainage stream, St Kevin Gulch, Colorado, by experimentally increasing the pH of the stream from about 4.0 to 6.5 and following the downstream changes in iron species. We used a solute transport model with variable flow to evaluate biogeochemical processes controlling downstream transport. We found that at pH 6.4 there was a rapid and large initial loss of ferrous iron concurrent with the precipitation of aluminium hydroxide. Below this reach, ferrous iron was conservative during the morning but there was a net downstream loss of ferrous iron around noon and in the afternoon. Calculation of net oxidation rates shows that the noontime loss rate was generally much faster than rates for the ferrous iron oxidation at pH 6 predicted by Singer and Stumm (1970. Science 167: 1121). The maintenance of ferrous iron concentrations in the morning is explained by the photoreduction of photoreactive ferric species, which are then depleted by noon. Copyright ?? 2001 John Wiley & Sons, Ltd.

  7. Spatial and Seasonal Variations of Heavy Metal Loads in Uyo Urban Drainage Stream under PS and NPS Pollution

    O. E. Essien


    Full Text Available The concentration of heavy metals (HM in the 4km urban drainage stream in Uyo was studied using grab and composite sampling of water from six stations on the stream, and analyzed by a multipurpose atomic absorption spectrophotometer. The data were statistically analyzed using SPSS version 17 software arid correlated between stations and among samples. HM contamination was evaluated with the coefficient and rate of dispersion between stations and the Normalized Scatter Coefficient (NSC. The seasonal distribution of metal pollution varied individually amongst metals at stations. The Fe and Pb concentrations exceeded the safe drinking water standard, rendering the water quality not acceptable for drinking; however, the quality was within the safe limit for crop production along the river bank. The relative.dominance of heavy metals followed a different sequence in upstream leachate effluent from all downstream stations. The NSC in dry-wet season was higher than in wet season, and was in the order: Fe>Cu>Zn>Pb, showing that large but variable concentration of Fe from PS and NPS contaminated the stream at faster rate in the wet season while Pb contaminated at nearly constant rate. However, in the dry season, Fe and Pb depleted at downstream at rates far higher than Zn as Cu was increasing. Fe and Pb could be good pollution monitor for total maximum daily load (TMDL pollution monitoring programme.

  8. Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

    Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon; Hwang, Yun Ho; Yang, Jung-Seok; O' Loughlin, Edward J.; Kwon, Man Jae


    To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity of the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. The elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.

  9. Monitoring correlative financial data streams by local pattern similarity

    Tao JIANG; Yu-cai FENG; Bin ZHANG; Zhong-sheng CAO; Ge FU; Jie SHI


    Developing tools for monitoring the correlations among thousands of financial data streams in all online fashion can be interesting and useful work.We aimed to find highly correlative financial data steams in local patterns.A novel distance metric function slope duration distance(SDD)is proposed,which is compatible with the characteristics of actual financial data streams.Moreover, a model monitoring correlations among local patterns(MCALP)is presented,which dramatically decreases the computational cost using an algorithm quickly online segmenting and pruning(QONSP)with O(1)time cost at each time tick t,and our proposed new grid structure.Experimental results showed that MCALP provides an improvement of several orders of magnitude in performance relative to traditional naive linear scan techniques and maintains high precision.Furthermore,the model is incremental,parallelizable,and has a quick response time.

  10. Pattern detection in stream networks: Quantifying spatialvariability in fish distribution

    Torgersen, Christian E.; Gresswell, Robert E.; Bateman, Doug


    Biological and physical properties of rivers and streams are inherently difficult to sample and visualize at the resolution and extent necessary to detect fine-scale distributional patterns over large areas. Satellite imagery and broad-scale fish survey methods are effective for quantifying spatial variability in biological and physical variables over a range of scales in marine environments but are often too coarse in resolution to address conservation needs in inland fisheries management. We present methods for sampling and analyzing multiscale, spatially continuous patterns of stream fishes and physical habitat in small- to medium-size watersheds (500–1000 hectares). Geospatial tools, including geographic information system (GIS) software such as ArcInfo dynamic segmentation and ArcScene 3D analyst modules, were used to display complex biological and physical datasets. These tools also provided spatial referencing information (e.g. Cartesian and route-measure coordinates) necessary for conducting geostatistical analyses of spatial patterns (empirical semivariograms and wavelet analysis) in linear stream networks. Graphical depiction of fish distribution along a one-dimensional longitudinal profile and throughout the stream network (superimposed on a 10-metre digital elevation model) provided the spatial context necessary for describing and interpreting the relationship between landscape pattern and the distribution of coastal cutthroat trout (Oncorhynchus clarki clarki) in western Oregon, U.S.A. The distribution of coastal cutthroat trout was highly autocorrelated and exhibited a spherical semivariogram with a defined nugget, sill, and range. Wavelet analysis of the main-stem longitudinal profile revealed periodicity in trout distribution at three nested spatial scales corresponding ostensibly to landscape disturbances and the spacing of tributary junctions.

  11. Natural decrease of dissolved arsenic in a small stream receiving drainages of abandoned silver mines in Guanajuato, Mexico.

    Arroyo, Yann Rene Ramos; Muñoz, Alma Hortensia Serafín; Barrientos, Eunice Yanez; Huerta, Irais Rodriguez; Wrobel, Kazimierz; Wrobel, Katarzyna


    Arsenic release from the abandoned mines and its fate in a local stream were studied. Physicochemical parameters, metals/metalloids and arsenic species were determined. One of the mine drainages was found as a point source of contamination with 309 μg L(-1) of dissolved arsenic; this concentration declined rapidly to 10.5 μg L(-1) about 2 km downstream. Data analysis confirmed that oxidation of As(III) released from the primary sulfide minerals was favored by the increase of pH and oxidation reduction potential; the results obtained in multivariate approach indicated that self-purification of water was due to association of As(V) with secondary solid phase containing Fe, Mn, Ca.

  12. Mapping spatial patterns of stream power and channel change along a gravel-bed river in northern Yellowstone

    Lea, Devin M.; Legleiter, Carl J.


    Stream power represents the rate of energy expenditure along a river and can be calculated using topographic data acquired via remote sensing or field surveys. This study sought to quantitatively relate temporal changes in the form of Soda Butte Creek, a gravel-bed river in northeastern Yellowstone National Park, to stream power gradients along an 8-km reach. Aerial photographs from 1994 to 2012 and ground-based surveys were used to develop a locational probability map and morphologic sediment budget to assess lateral channel mobility and changes in net sediment flux. A drainage area-to-discharge relationship and DEM developed from LiDAR data were used to obtain the discharge and slope values needed to calculate stream power. Local and lagged relationships between mean stream power gradient at median peak discharge and volumes of erosion, deposition, and net sediment flux were quantified via spatial cross-correlation analyses. Similarly, autocorrelations of locational probabilities and sediment fluxes were used to examine spatial patterns of sediment sources and sinks. Energy expended above critical stream power was calculated for each time period to relate the magnitude and duration of peak flows to the total volumetric change in each time increment. Collectively, we refer to these methods as the stream power gradient (SPG) framework. The results of this study were compromised by methodological limitations of the SPG framework and revealed some complications likely to arise when applying this framework to small, wandering, gravel-bed rivers. Correlations between stream power gradients and sediment flux were generally weak, highlighting the inability of relatively simple statistical approaches to link sub-budget cell-scale sediment dynamics to larger-scale driving forces such as stream power gradients. Improving the moderate spatial resolution techniques used in this study and acquiring very-high resolution data from recently developed methods in fluvial remote

  13. Diel cycling of zinc in a stream impacted by acid rock drainage: initial results from a new in situ Zn analyzer.

    Chapin, Thomas P; Nimick, David A; Gammons, Christopher H; Wanty, Richard B


    Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 microg/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage.

  14. Diel cycling of zinc in a stream impacted by acid rock drainage: Initial results from a new in situ Zn analyzer

    Chapin, T.P.; Nimick, D.A.; Gammons, C.H.; Wanty, R.B.


    Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 ??g/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage. ?? Springer Science+Business Media B.V. 2006.

  15. Spatial patterns of some trace elements in four Swedish stream networks

    J. Temnerud


    Full Text Available Four river basins in Southern Sweden, catchment size 0.3 to maximum 127 km2 (median 1.9, were sampled in October 2007. The 243 samples were analysed for 26 trace elements (Ag, As, Au, Ba, Be, Bi, Cd, Co, Cr, Cu, Ga, Ge, In, La, Li, Mo, Ni, Pb, Sb, Se, Sn, Tl, Ti, U, V and Zn to identify spatial patterns within drainage networks. The sampling design made it possible to compare the difference between 40 stream reaches, 53 stream junctions with 107 tributaries vs. downstream reaches and 36 lakes with 77 inlets vs. outlets comparisons. The largest concentration differences (at reaches, junctions and lakes were observed for lakes, with outlets usually having lower concentration compared to the inlets for As, Ba, Be, Bi, Cd, Co, Cr, Ga, Ge, Ni, Pb, Sn, Ti, Tl, U, V and Zn. Significantly lower concentrations were observed for Co and Cd when comparing headwaters with downstream sites in each catchment. We found no evidence for elevated concentration of heavy metals Cd, Cu, Zn or Pb in the two acidified areas of South-west Sweden. Common factor analysis revealed that As, Bi, Cr, Ga, Ge, Tl, V co-vary positively with Al, Fe and total organic carbon (TOC and negatively with La, Li and pH. A better understanding of the quantitative removal of organic carbon and iron will aid in understanding metal fluxes from landscapes rich in organic matter and iron.

  16. Landscape scale patterns in the character of natural organic matter in a Swedish boreal stream network

    J. Temnerud


    Full Text Available This paper defines landscape-scale patterns in the character of natural organic matter (NOM and tests for relationships to catchment soil, vegetation and topography. The drainage network of a boreal catchment, subcatchment size 0.12–78 km2, in Northern Sweden was sampled in August 2002 during a period of stable low water flow. The NOM was characterized with UV/Vis spectroscopy, fluorescence, XAD-8 fractionation (%humic substances, gel permeation chromatography (apparent molecular weight, and elemental composition (C:N. The largest spatial variation was found for C:N, absorbance ratio, and specific visible absorptivity. The lowest variation was in fluorescence index, %humic substances and molecular retention time. The variation in total organic carbon (TOC, iron and aluminium concentration was more than twice that of C:N. Between headwater and downstream sites no significant changes were distinguished in the NOM character. At stream reaches, junctions and lakes little change (<10% in NOM character was observed. Common factor analysis and partial least squares regression (PLS revealed that the spatial variation in surface coverage of lakes and mires could explain some of the variation of TOC and NOM character. Our suggestion is that the mosaic of landscape elements (different amounts of water from lakes, forest soil and mires delivers NOM with varying characteristics to a channel network that mixes conservatively downstream, with possible small changes at some stream reaches, junctions and lakes.

  17. Landscape scale patterns in the character of natural organic matter in a Swedish boreal stream network

    J. Temnerud


    Full Text Available This paper defines landscape-scale patterns in the character of natural organic matter (NOM and tests for relationships to catchment soil, vegetation and topography. The drainage network of a boreal catchment, subcatchment size 0.12–78 km2, in Northern Sweden was sampled in August 2002 during a period of stable low water flow. The NOM was characterized with UV/Vis spectroscopy, fluorescence, XAD-8 fractionation (%humic substances, gel permeation chromatography (apparent molecular weight, and elemental composition (C:N. The largest spatial variation was found for C:N, absorbance ratio, and specific visible absorptivity. The lowest variation was in fluorescence index, %humic substances and molecular retention time. But the variation in total organic carbon (TOC, iron and aluminium concentration was more than twice that of C:N. Between headwater and downstream sites no significant changes were distinguished in the NOM character. At stream reaches, junctions and lakes little change (<10% in NOM character was observed. Common factor analysis and partial least squares regression (PLS revealed that the spatial variation in surface coverage of lakes and mires could explain some of the variation of TOC and NOM character. Our suggestion is that the mosaic of landscape elements (different amounts of water from lakes, forest soil and mires delivers NOM with varying characteristics to a channel network that mixes conservatively downstream, with possible small changes at some stream reaches, junctions and lakes.

  18. Correlation between theoretical anatomical patterns of lymphatic drainage and lymphoscintigraphy findings during sentinel node detection in head and neck melanomas

    Vidal, Monica; Ruiz, Diana Milena [Hospital Clinic de Barcelona, Nuclear Medicine Department, Barcelona (Spain); Vidal-Sicart, Sergi; Paredes, Pilar; Pons, Francesca [Hospital Clinic de Barcelona, Nuclear Medicine Department, Barcelona (Spain); Institut d' Investigacions Biomediques Agusti Pi i Sunyer (IDIBAPS), Barcelona (Spain); Torres, Ferran [Hospital Clinic Barcelona, Statistical of Biostatistics and Data Management Core Facility, IDIBAPS, Barcelona (Spain); Universitat Autonoma de Barcelona, Biostatistics Unit, Faculty of Medicine, Barcelona (Spain)


    In the diagnosis of head and neck melanoma, lymphatic drainage is complex and highly variable. As regional lymph node metastasis is one of the most important prognostic factors, lymphoscintigraphy can help map individual drainage patterns. The aim of this study was to compare the results of lymphoscintigraphy and sentinel lymph node (SLN) detection with theoretical anatomical patterns of lymphatic drainage based on the location of the primary tumour lesion in patients with head and neck melanoma. We also determined the percentage of discrepancies between our lymphoscintigraphy and the theoretical location of nodal drainage predicted by a large lymphoscintigraphic database, in order to explain recurrence and false-negative SLN biopsies. In this retrospective study of 152 patients with head and neck melanoma, the locations of the SLNs on lymphoscintigraphy and detected intraoperatively were compared with the lymphatic drainage predicted by on-line software based on a large melanoma database. All patients showed lymphatic drainage and in all patients at least one SLN was identified by lymphoscintigraphy. Of the 152 patients, 4 had a primary lesion in areas that were not described in the Sydney Melanoma Unit database, so agreement could only be evaluated in 148 patients. Agreement between lymphoscintigraphic findings and the theoretical lymphatic drainage predicted by the software was completely concordant in 119 of the 148 patients (80.4 %, 95 % CI 73.3 - 86 %). However, this concordance was partial (some concordant nodes and others not) in 18 patients (12.2 %, 95 % CI 7.8 - 18.4 %). Discordance was complete in 11 patients (7.4 %, 95 % CI 4.2 - 12.8 %). In melanoma of the head and neck there is a high correlation between lymphatic drainage found by lymphoscintigraphy and the predicted drainage pattern and basins provided by a large reference database. Due to unpredictable drainage, preoperative lymphoscintigraphy is essential to accurately detect the SLNs in head and

  19. Influences of acid mine drainage and thermal enrichment on stream fish reproduction and larval survival

    Hafs, Andrew W.; Horn, C.D.; Mazik, P.M.; Hartman, K.J.


    Potential effects of acid mine drainage (AMD) and thermal enrichment on the reproduction of fishes were investigated through a larval-trapping survey in the Stony River watershed, Grant County, WV. Trapping was conducted at seven sites from 26 March to 2 July 2004. Overall larval catch was low (379 individuals in 220 hours of trapping). More larval White Suckers were captured than all other species. Vectors fitted to nonparametric multidimensional scaling ordinations suggested that temperature was highly correlated to fish communities captured at our sites. Survival of larval Fathead Minnows was examined in situ at six sites from 13 May to 11 June 2004 in the same system. Larval survival was lower, but not significantly different between sites directly downstream of AMD-impacted tributaries (40% survival) and non-AMD sites (52% survival). The lower survival was caused by a significant mortality event at one site that coincided with acute pH depression in an AMD tributary immediately upstream of the site. Results from a Cox proportional hazard test suggests that low pH is having a significant negative influence on larval fish survival in this system. The results from this research indicate that the combination of low pH events and elevated temperature are negatively influencing the larval fish populations of the Stony River watershed. Management actions that address these problems would have the potential to substantially increase both reproduction rates and larval survival, therefore greatly enhancing the fishery.

  20. Evaluating remedial alternatives for an acid mine drainage stream: A model post audit

    Runkel, Robert L.; Kimball, Briant A.; Walton-Day, Katherine; Verplanck, Philip L.; Broshears, Robert E.


    A post audit for a reactive transport model used to evaluate acid mine drainage treatment systems is presented herein. The post audit is based on a paired synoptic approach in which hydrogeochemical data are collected at low (existing conditions) and elevated (following treatment) pH. Data obtained under existing, low-pH conditions are used for calibration, and the resultant model is used to predict metal concentrations observed following treatment. Predictions for Al, As, Fe, H+, and Pb accurately reproduce the observed reduction in dissolved concentrations afforded by the treatment system, and the information provided in regard to standard attainment is also accurate (predictions correctly indicate attainment or nonattainment of water quality standards for 19 of 25 cases). Errors associated with Cd, Cu, and Zn are attributed to misspecification of sorbent mass (precipitated Fe). In addition to these specific results, the post audit provides insight in regard to calibration and sensitivity analysis that is contrary to conventional wisdom. Steps taken during the calibration process to improve simulations of As sorption were ultimately detrimental to the predictive results, for example, and the sensitivity analysis failed to bracket observed metal concentrations.

  1. Pore network modeling of drainage process in patterned porous media: a quasi-static study

    Zhang, Tao


    This work represents a preliminary investigation on the role of wettability conditions on the flow of a two-phase system in porous media. Since such effects have been lumped implicitly in relative permeability-saturation and capillary pressure-saturation relationships, it is quite challenging to isolate its effects explicitly in real porous media applications. However, within the framework of pore network models, it is easy to highlight the effects of wettability conditions on the transport of two-phase systems. We employ quasi-static investigation in which the system undergo slow movement based on slight increment of the imposed pressure. Several numerical experiments of the drainage process are conducted to displace a wetting fluid with a non-wetting one. In all these experiments the network is assigned different scenarios of various wettability patterns. The aim is to show that the drainage process is very much affected by the imposed pattern of wettability. The wettability conditions are imposed by assigning the value of contact angle to each pore throat according to predefined patterns.

  2. Performance of an open limestone channel for treating a stream affected by acid rock drainage (León, Spain).

    Santofimia, Esther; López-Pamo, Enrique


    The generation of acid rock drainage (ARD) was observed after the oxidation dissolution of pyrite-rich black shales, which were excavated during the construction of a highway in León (Spain). ARDs are characterized by the presence of high concentrations of sulfate and metals (Al, Fe, Mn, Zn, Cu, Co, Ni, Th, and U) that affect the La Silva stream. Dissolved element concentrations showed values between one and four orders of magnitude higher than those of natural waters of this area. A passive treatment system was constructed; the aim of which was to improve the quality of the water of the stream. This work provides a hydrochemical characterization of the La Silva stream after its transit through the different elements that constitute the passive treatment system (open limestone channel (OLC), small ponds, and a wetland), during its first year of operation. The passive treatment system has two sections separated by a tunnel 230 m long. The first section, which stretches between the highway and the tunnel entrance, is an OLC 350 m long with a slope of 16 %. The second section, which stretches from the tunnel exit to the end wetland, has a length of 700 m and a slope of 6 %; it is in this section where six small ponds are located. In the first section of this passive treatment system, the OLC was effectively increasing the pH from 3 to 4-4.5 and eliminating all of the dissolved Fe and the partially dissolved Al. These elements, after hydrolysis at a pH 3-3.5 and 4-4.5, respectively, had precipitated as schwertmannite and hydrobasaluminite, while other dissolved metals were removed totally or partially for adsorption by the precipitates and/or by coprecipitation. The second section receives different inputs of water such as ARDs and natural waters. After exiting the treatment system, the stream is buffered by Al at a pH of 4-4.3, showing high Al concentrations (19-101 mg/L) but with a complete removal of dissolved Fe. Unfortunately, the outflow shows similar or

  3. The precipitation of indium at elevated pH in a stream influenced by acid mine drainage.

    White, Sarah Jane O; Hussain, Fatima A; Hemond, Harold F; Sacco, Sarah A; Shine, James P; Runkel, Robert L; Walton-Day, Katherine; Kimball, Briant A


    Indium is an increasingly important metal in semiconductors and electronics and has uses in important energy technologies such as photovoltaic cells and light-emitting diodes (LEDs). One significant flux of indium to the environment is from lead, zinc, copper, and tin mining and smelting, but little is known about its aqueous behavior after it is mobilized. In this study, we use Mineral Creek, a headwater stream in southwestern Colorado severely affected by heavy metal contamination as a result of acid mine drainage, as a natural laboratory to study the aqueous behavior of indium. At the existing pH of ~3, indium concentrations are 6-29μg/L (10,000× those found in natural rivers), and are completely filterable through a 0.45μm filter. During a pH modification experiment, the pH of the system was raised to >8, and >99% of the indium became associated with the suspended solid phase (i.e. does not pass through a 0.45μm filter). To determine the mechanism of removal of indium from the filterable and likely primarily dissolved phase, we conducted laboratory experiments to determine an upper bound for a sorption constant to iron oxides, and used this, along with other published thermodynamic constants, to model the partitioning of indium in Mineral Creek. Modeling results suggest that the removal of indium from the filterable phase is consistent with precipitation of indium hydroxide from a dissolved phase. This work demonstrates that nonferrous mining processes can be a significant source of indium to the environment, and provides critical information about the aqueous behavior of indium. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. The precipitation of indium at elevated pH in a stream influenced by acid mine drainage

    White, Sarah Jane O.; Hussain, Fatima A.; Hemond, Harold F.; Sacco, Sarah A.; Shine, James P.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.


    Indium is an increasingly important metal in semiconductors and electronics and has uses in important energy technologies such as photovoltaic cells and light-emitting diodes (LEDs). One significant flux of indium to the environment is from lead, zinc, copper, and tin mining and smelting, but little is known about its aqueous behavior after it is mobilized. In this study, we use Mineral Creek, a headwater stream in southwestern Colorado severely affected by heavy metal contamination as a result of acid mine drainage, as a natural laboratory to study the aqueous behavior of indium. At the existing pH of ~ 3, indium concentrations are 6–29 μg/L (10,000 × those found in natural rivers), and are completely filterable through a 0.45 μm filter. During a pH modification experiment, the pH of the system was raised to > 8, and > 99% of the indium became associated with the suspended solid phase (i.e. does not pass through a 0.45 μm filter). To determine the mechanism of removal of indium from the filterable and likely primarily dissolved phase, we conducted laboratory experiments to determine an upper bound for a sorption constant to iron oxides, and used this, along with other published thermodynamic constants, to model the partitioning of indium in Mineral Creek. Modeling results suggest that the removal of indium from the filterable phase is consistent with precipitation of indium hydroxide from a dissolved phase. This work demonstrates that nonferrous mining processes can be a significant source of indium to the environment, and provides critical information about the aqueous behavior of indium.

  5. Ice-dammed lake drainage in west Greenland: Drainage pattern and implications on ice flow and bedrock motion

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Bjørk, Anders


    Ice-dammed lakes drain frequently in Greenland, but the impacts of these events differ between sites. Here we study the quasi-cyclic behavior of the ~40 km2 Lake Tininnilik in west Greenland and its impact on ice flow and crustal deformation. Data reveal rapid drainage of 1.83 ± 0.17 km3 of water...... in less than 7 days in 2010, leading to a speedup of the damming glacier, and an instantaneous modeled elastic bedrock uplift of 18.6 ± 0.1 mm confirmed by an independent lakeside GPS record. Since ice-dammed lakes are common on Greenland, our results highlight the importance of including other sources...... of surface loading in addition to ice mass change, when assessing glacial isostatic adjustment or elastic rebound using geodetic data. Moreover, the results illustrates a linkage between subglacial discharge and ice surface velocity, important for assessing ice flux, and thus mass balance, in a future...

  6. Synoptic sampling and principal components analysis to identify sources of water and metals to an acid mine drainage stream

    Byrne, Patrick; Runkel, Robert L.; Walton-Day, Katie


    Combining the synoptic mass balance approach with principal components analysis (PCA) can be an effective method for discretising the chemistry of inflows and source areas in watersheds where contamination is diffuse in nature and/or complicated by groundwater interactions. This paper presents a field-scale study in which synoptic sampling and PCA are employed in a mineralized watershed (Lion Creek, Colorado, USA) under low flow conditions to (i) quantify the impacts of mining activity on stream water quality; (ii) quantify the spatial pattern of constituent loading; and (iii) identify inflow sources most responsible for observed changes in stream chemistry and constituent loading. Several of the constituents investigated (Al, Cd, Cu, Fe, Mn, Zn) fail to meet chronic aquatic life standards along most of the study reach. The spatial pattern of constituent loading suggests four primary sources of contamination under low flow conditions. Three of these sources are associated with acidic (pH <3.1) seeps that enter along the left bank of Lion Creek. Investigation of inflow water (trace metal and major ion) chemistry using PCA suggests a hydraulic connection between many of the left bank inflows and mine water in the Minnesota Mine shaft located to the north-east of the river channel. In addition, water chemistry data during a rainfall-runoff event suggests the spatial pattern of constituent loading may be modified during rainfall due to dissolution of efflorescent salts or erosion of streamside tailings. These data point to the complexity of contaminant mobilisation processes and constituent loading in mining-affected watersheds but the combined synoptic sampling and PCA approach enables a conceptual model of contaminant dynamics to be developed to inform remediation.

  7. Impact of long-term drainage on summer groundwater flow patterns in the Mer Bleue peatland, Ontario, Canada

    B. J. Kopp


    Full Text Available Long-term impacts of drier conditions on the hydrology of northern peatlands are poorly understood. We used long-term drainage near a historic drainage ditch, separating an area from the main peatland, as an analogue for long-term drying in a northern temperate bog. The objective was to identify the impact of drier conditions on ecohydrological processes and groundwater flow patterns in an area now forested and an area that maintained a bog-like character. Groundwater flow patterns alternated between mostly downward flow and occasionally upward flow in the bog area and were mostly upward-orientated in the forested area, which suggested that there the flow pattern had shifted from bog- to fen-like conditions. Flow patterns were in agreement with changes in post-drainage hydraulic conductivities, storage capacity of the peat and water table levels. Compared to the bog, hydraulic conductivities in the forested area were one to three orders of magnitude lower in the uppermost 0.75 m of peat (paired t test, p < 0.05. Bulk density had increased and the water table level was lower and more strongly fluctuating in the forested area. Our findings suggest hydraulic gradients and flow patterns have changed due to increased evapotranspiration and interception with the emergence of a tree cover. The smaller size of the now-forested area relative to the remaining bog area appeared to be important for the hydrological change. With the main Mer Bleue bog as hinterland, enhanced runoff to the drainage channel had little effect on hydrologic and vegetation patterns. In the cut-off, smaller, now forested area pervasive changes in vegetation and hydrologic processes occurred. The difference in response to local drainage raises questions about tipping points with respect to the impact of drying on peatland ecosystems that need to be addressed in future research.

  8. Gully Growth Patterns and Soil Loss under Rainfall at Urban Underground Drainage Construction Site, Uyo

    O.E. Essien


    Full Text Available This study investigated, evaluated and modeled patterns of growth of gully morphometric dimension and soil loss volume under prevailing rainfall on the slopes of land graded for the construction of underground drainage at Uyo but delayed in completion. Land grading at underground (tunnel drainage construction site rendered the exposed surface very impervious but young ephemeral gullies developed due to delays in completion. Data on gully morphometric dimension, soil loss and depth of rainfall were analyzed using SPSS ver. 17 statistical package. Mean gully growth in length, width and depth were different at 2.54±0.86, 0.923±0.29 and 0.41±0.11 m, respectively, yielding 3.87±0.08 m2 as mean volume of soil loss at full stage. Cubic polynomial was best-fit model for growth in length (R2 = 79% and width (R2 = 69% using weekly rainfall for an annual season. All gully sites had constant depth change, better predicted by quadratic (R2 = 13% than linear (R2 = 9% functions. Mean volume of soil loss per unit rainfall amount varied with low, medium and high rainfall amount and was highest at slope bottom (33 cm3/cm and least at the crest (6.99 cm3/cm with R2 = 38-34%. Land grading to impervious sublayer produced constant depth change in all gullies at the sites. The models for morphometric incremental growth and soil loss volume under the rainfall effect was significantly improved (p<0.05 by bifurcating the lumped annual curve into two growth periods in a year: the periods for increasing rainfall (from week 10-30 and for receding rainfall (from week 31-43 in a year and applying quadratic regressing functions on each (R2 = 91-99%. Rainfall was the principal gully factor and construction delays should be avoided.

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

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


    these downstream valleys, a majority of remobilized sediment (62%) is coming from first- and second-order tributaries because they represent the largest fraction of cumulative channel length in the drainage network. Floodplain segments are discontinuous along low-order tributaries but sediment contributions reported here are adjusted to account for the percent valley length bordered by floodplain sediments. Average annual lateral migration rates ranged from 0.04-0.19 m/y with higher rates along larger streams; however, when scaled by channel width, we find that on average streams are migrating 2.5% of channel width across all drainage areas. Direct measurements reported here account for in-channel deposition, but not floodplain deposition. Other studies in the region have demonstrated that redeposition on floodplains is an important component of the sediment budget and are necessary to avoid overestimating streambank erosion contributions to watershed sediment yield. We therefore adjust our measured sediment contributions by estimating the mass of sediment redeposited on floodplains within our study area. With this adjustment, extrapolated net stream bank sediment yields (72 Mg/km2/yr) are equivalent to 70% of the estimated average Piedmont watershed yield (104 Mg/km2/yr) cited by previous authors. Furthermore, our results demonstrate that measurements over adequate spatial and temporal scales- rather than short-term, localized observations- are required to accurately capture and measure patterns of streambank erosion across the drainage network. It is important to note that upland erosion rates- not measured here- have been reported with equivalent and greater magnitude for forested and cropland areas within the Maryland Piedmont and therefore should not be assumed to contribute only 30% of the total.

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

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


    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

  11. Neotectonic formation of drainage patterns and their palaeohydrological implications for the Okwa River catchment, Botswana

    Hartmann, Kai; Schmidt, Mareike; Shemang, Elisha; Zhang, Shuping; Frank, Riedel


    Large inter- and intramontane endorheic basins provide long term archives of environmental change, often integrating regional to continental climate driven process dynamics of huge drainage systems. On one hand the large-scale integration can be regarded as an advantage by averaging small-scale variations of either local hydrological peculiarities or random triggered drainage behaviour (e.g. internal thresholds, tectonics, etc.) and thus just recording atmospheric circulation pattern up to hemispherical scales with millennial resolution. Otherwise, with increasing basin size the process dynamic and their response system along one or more sediment cascades often become a complexity resulting in crucial problems of sedimentological archive interpretations by e.g. signal interference, equifinality or even multiple reworking. Therefore, studies of geomorphological or hydrological response processes and ecological adaption can only be undertaken on sub-catchment scale considering process dynamics along pathways. For southern-hemispheric palaeoclimate reconstruction of land-ocean linkages, Makgadikgadi Basin - as the largest (c. 37,000 km2) and deepest depression in the middle Kalahari - provides a fluvio-lacustrine archive in high-continental position since at least 300 kyr BP. Recent studies suggest a mega-lake high-stand within the basin for the Last Glacial Maximum (LGM) For the hydrological persistence of the lake for about 6 kyrs, the since Heinrich Event 1 (17-16 ka) inactive Okwa River seems to play a key role indicating a northward-shift of the winter rainfall zone. However, beside some dating of exposed shell bearing sediments at the river mouth, a thorough investigation of the c. 129,000 km2 drainage system is missing. Our presentation aims to point out the linkages between neotectonic activity and sediment transport. The combination of adaptive DEM-filter and multispectral remote sensing data reveals obvious traps (of neotectonic origin) of small temporary

  12. Influence of a large dam on the longitudinal patterns of fish assemblages in Qingyi Stream.

    Sui, Xiao-Yun; Lu, Zhi; Yan, Yun-Zhi; Chen, Yi-Feng; Jia, Yin-Tao


    Using seasonally collected data (2009-2010) from 15 sampling sites that represent first- to fifth-order streams within the Qingyi watershed, we examined the spatio-temporal patterns of fish assemblages along two longitudinal gradients to explore the effects of a large dam on fish assemblages at the watershed scale. No significant variation was observed in either species richness or assemblage structure across seasons. Species richness significantly varied according to stream order and gradient. Dam construction appeared to decrease species richness upstream substantially, while a significant decrease between gradients only occurred within fourth-order streams. Along the gradient without the large dam, fish assemblage structures presented distinct separation between two neighboring stream orders, with the exception of fourth-order versus fifth-order streams. However, the gradient disrupted by a large dam displayed the opposite pattern in the spatial variation of fish assemblages related with stream orders. Significant between-gradient differences in fish assemblage structures were only observed within fourth-order streams. Species distributions were determined by local habitat environmental factors, including elevation, substrate, water depth, current discharge, wetted width, and conductivity. Our results suggested that dam construction might alter the longitudinal pattern in fish species richness and assemblage structure in Qingyi Stream, despite the localized nature of the ecological effect of dams.

  13. CO2 time series patterns in contrasting headwater streams of North America

    Crawford, John T.; Stanley, Emily H.; Dornblaser, Mark M.; Striegl, Rob


    We explored the underlying patterns of temporal stream CO2 partial pressure (pCO2) variability using highfrequency sensors in seven disparate headwater streams distributed across the northern hemisphere. We also compared this dataset of [40,000 pCO2 records with other published records from lotic systems. Individual stream sites exhibited relatively distinct pCO2 patterns over time with few consistent traits across sites. Some sites showed strong diel variability, some exhibited increasing pCO2 with increasing discharge, whereas other streams had reduced pCO2 with increasing discharge or no clear response to changes in flow. The only ‘‘universal’’ signature observed in headwater streams was a late summer pCO2 maxima that was likely driven by greatest rates of organic matter respiration due to highest annual temperatures. However, we did not observe this seasonal pattern in a southern hardwood forest site, likely because the region was transitioning from a severe drought. This work clearly illustrates the heterogeneous nature of headwater streams, and highlights the idiosyncratic nature of a non-conservative solute that is jointly influenced by physics, hydrology, and biology. We suggest that future researchers carefully select sensor locations (within and among streams) and provide additional contextual information when attempting to explain pCO2 patterns.

  14. Spatial and temporal patterns of pesticide concentrations in streamflow, drainage and runoff in a small Swedish agricultural catchment.

    Sandin, Maria; Piikki, Kristin; Jarvis, Nicholas; Larsbo, Mats; Bishop, Kevin; Kreuger, Jenny


    A better understanding of the dominant source areas and transport pathways of pesticide losses to surface water is needed for targeting mitigation efforts in a more cost-effective way. To this end, we monitored pesticides in surface water in an agricultural catchment typical of one of the main crop production regions in Sweden. Three small sub-catchments (88-242ha) were selected for water sampling based on a high-resolution digital soil map developed from proximal sensing methods and soil sampling; one sub-catchment had a high proportion of clay soils, another was dominated by coarse sandy soils while the third comprised a mix of soil types. Samples were collected from the stream, from field drains discharging into the stream and from within-field surface runoff during spring and early summer in three consecutive years. These samples were analyzed by LC-MS/MS for 99 compounds, including most of the polar and semi-polar pesticides frequently used in Swedish agriculture. Information on pesticide applications (products, doses and timing) was obtained from annual interviews with the farmers. There were clear and consistent differences in pesticide occurrence in the stream between the three sub-catchments, with both the numbers of detected compounds and concentrations being the largest in the area with a high proportion of clay soils and with very few detections in the sandy sub-catchment. Macropore flow to drains was most likely the dominant loss pathway in the studied area. Many of the compounds that were detected in drainage and stream water samples had not been applied for several years. This suggests that despite the predominant role of fast flow pathways in determining losses to the stream, long-term storage along the transport pathways also occurs, presumably in subsoil horizons where degradation is slow. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Impact of long-term drainage on summer groundwater flow patterns in the Mer Bleue peatland, Ontario, Canada

    B. J. Kopp


    Full Text Available Long-term impacts of a drier climate on coupled hydrology and carbon cycling in northern peatlands are poorly understood. We used a historic drainage ditch, separating an area from the main peatland, as an analogue for long-term drying in a northern temperate bog. The objective was to identify the impact of drier conditions on ecohydrological processes and groundwater flow patterns in an area now wooded and an area that maintained bog character. Groundwater flow patterns alternated between downward flow and upward flow in the bog area and were mostly upward orientated in the wooded area. Flow patterns were in agreement with changes in post-drainage hydraulic conductivities, storage capacity of the peat and hydraulic gradients. Compared to the bog, hydraulic conductivities in the wooded area were one to three orders of magnitude lower in the uppermost 0.75 m (paired t-test, p<0.05 of peat but partly higher below. Bulk density had increased and the water table level was lower and more strongly fluctuating. Our findings suggest hydraulic gradients and flow patterns have changed due to increased evapotranspiration and interception with the emergence of a tree cover. The smaller size of the now-forested area relative to the remaining bog area appeared to be important for the hydrological change. When water supply from undisturbed areas was large, enhanced runoff to the drainage channel had little effect on hydrologic patterns and vegetation pattern, whereas in the smaller, now forested area pervasive changes in vegetation and hydrologic processes occurred. This finding raises questions about tipping points with respect to the impact of drying on bog ecosystems that need to be addressed in future research.

  16. Seasonal patterns in stream periphyton fatty acids and community benthic algal composition in six high quality headwater streams

    Honeyfield, Dale C.; Maloney, Kelly O.


    Fatty acids are integral components of periphyton and differ among algal taxa. We examined seasonal patterns in periphyton fatty acids in six minimally disturbed headwater streams in Pennsylvania’s Appalachian Mountains, USA. Environmental data and periphyton were collected across four seasons for fatty acid and algal taxa content. Non-metric multidimensional scaling ordination suggested significant seasonal differences in fatty acids; an ordination on algal composition revealed similar seasonal patterns, but with slightly weaker separation of summer and fall. Summer and fall fatty acid profiles were driven by temperature, overstory cover, and conductivity and winter profiles by measures of stream size. Ordination on algal composition suggested that summer and fall communities were driven by overstory and temperature, whereas winter communities were driven by velocity. The physiologically important fatty acid 18:3ω6 was highest in summer and fall. Winter samples had the highest 20:3ω3. Six saturated fatty acids differed among the seasons. Periphyton fatty acids profiles appeared to reflect benthic algal species composition. This suggests that periphyton fatty acid composition can be useful in characterizing basal food resources and stream water quality.


    李继彬; 段晚锁


    By using the theory of the generalized perturbed Hamiltonian systems, it is shown that there exist periodic stream lines in the three-dimensional square cell pattern of Rayleigh-Benard convection. The result means that our method enables this three dimensional flow pattern to be described in an unambiguous manner, and some experimental results of other authors can be explained.

  18. Fine-scale genetic structure patterns in two freshwater fish species, Geophagus brasiliensis (Osteichthyes, Cichlidae) and Astyanax altiparanae (Osteichthyes, Characidae) throughout a Neotropical stream.

    Ferreira, D G; Lima, S C; Frantine-Silva, W; Silva, J F; Apolinário-Silva, C; Sofia, S H; Carvalho, S; Galindo, B A


    Streams are very important environments for Neotropical freshwater fish fauna, and possess a high number of species. These small drainages are also highlighted by their intrinsic biological and physicochemical features; however, knowledge on the genetic distribution of fish in these drainages is limited. Therefore, in the present study, RAPD (random amplified polymorphic DNA) and microsatellite markers were used to analyze population differentiation and gene flow of Astyanax altiparanae and Geophagus brasiliensis from three sites (high, medium, and low) throughout the Penacho stream (about 32 km long), which is a Neotropical stream. Both markers revealed higher levels of genetic diversity levels for A. altiparanae (: 90.05; HS: 0.350) compared to G. brasiliensis (: 30.43; HS: 0.118), which may be related to the particular biology of each species. AMOVA revealed significant genetic variation among populations of each species. All pairwise ΦST values were significant, ranging from 0.020 to 0.056 for A. altiparanae samples, and from 0.065 to 0.190 for G. brasiliensis samples. Bayesian clustering analysis corroborated these results and revealed clusters of both A. altiparanae (two based on RAPD data) and G. brasiliensis (two based on RAPD data and three on microsatellite data). Gene flow estimates showed that there were similar rates of migration among A. altiparanae samples and low rates of migration among some G. brasiliensis samples. These results suggest patterns of fine-scale genetic structure for both species in the Penacho stream. This information may enhance knowledge of Neotropical streams and may be useful for future management and conservation activities.

  19. Discovering Patterns in Symbolic Streams%符号流中的模式发现

    李刚; 童铑


    The idea of discovering patterns in data seems to be essential for decision making in our social activities. This paper presents a simple algorithm which can be used to detect such patterns in elementary sequences of symbols. It adopts a data compression algorithm to seek for interesting patterns, which is important in understanding the way that the input symbol stream repeats itself. In this paper, the algorithm and related data structures are described in detail, and an illustrative example is given.

  20. Discovering Patterns in Symbolic Streams%符号流中的模式发现

    李刚; 童頫


    The idea of discovering patterns in data seems to be essential for decision making in our social activities. This paper presents a simple algorithm which can be used to detect such patterns in elementary sequences of symbols. It adopts a data compression algorithm to seek for interesting patterns, which is important in understanding the way that the input symbol stream repeats itself. In this paper, the algorithm and related data structures are described in detail, and an illustrative example is given.

  1. Role of hydrous iron oxide formation in attenuation and diel cycling of dissolved trace metals in a stream affected by acid rock drainage

    Parker, S.R.; Gammons, C.H.; Jones, C.A.; Nimick, D.A.


    Mining-impacted streams have been shown to undergo diel (24-h) fluctuations in concentrations of major and trace elements. Fisher Creek in south-central Montana, USA receives acid rock drainage (ARD) from natural and mining-related sources. A previous diel field study found substantial changes in dissolved metal concentrations at three sites with differing pH regimes during a 24-h period in August 2002. The current work discusses follow-up field sampling of Fisher Creek as well as field and laboratory experiments that examine in greater detail the underlying processes involved in the observed diel concentration changes. The field experiments employed in-stream chambers that were either transparent or opaque to light, filled with stream water and sediment (cobbles coated with hydrous Fe and Al oxides), and placed in the stream to maintain the same temperature. Three sets of laboratory experiments were performed: (1) equilibration of a Cu(II) and Zn(II) containing solution with Fisher Creek stream sediment at pH 6.9 and different temperatures; (2) titration of Fisher Creek water from pH 3.1 to 7 under four different isothermal conditions; and (3) analysis of the effects of temperature on the interaction of an Fe(II) containing solution with Fisher Creek stream sediment under non-oxidizing conditions. Results of these studies are consistent with a model in which Cu, Fe(II), and to a lesser extent Zn, are adsorbed or co-precipitated with hydrous Fe and Al oxides as the pH of Fisher Creek increases from 5.3 to 7.0. The extent of metal attenuation is strongly temperature-dependent, being more pronounced in warm vs. cold water. Furthermore, the sorption/co-precipitation process is shown to be irreversible; once the Cu, Zn, and Fe(II) are removed from solution in warm water, a decrease in temperature does not release the metals back to the water column. ?? 2006 Springer Science+Business Media B.V.

  2. Landscape scale patterns in the character of natural organic matter in a Swedish boreal stream network

    Temnerud, J.; A. Düker; Karlsson, S.; Allard, B; S. Köhler; K. Bishop


    This paper defines landscape-scale patterns in the character of natural organic matter (NOM) and tests for relationships to catchment soil, vegetation and topography. The drainage network of a boreal catchment, subcatchment size 0.12–78 km2, in Northern Sweden was sampled in August 2002 during a period of stable low water flow. The NOM was characterized with UV/Vis spectroscopy, fluorescence, XAD-8 fractionation (%humic substances), gel permeation chromatography (appare...

  3. Report of progress of stream measurements for the calendar year 1905, Part XI, Colorado River drainage above Yuma

    Hinderlider, M.C.; Swendsen, G.L.


    The hydrographic work of the United States Geological Survey includes the collection of facts concerning and the study of conditions affecting the behavior of water from the time it reaches the earh as rain or snow until it joins the oceans or great navigable rivers. These investigations became a distinct feature of the work of the Survey in the fall of 1888, when an instruction camp was established at Embudo, N. Mex. The frist specific appropriation for gaging streams was amde by the act of August 18, 1894, which contained an item of $12, 500 'for gaging the streams and determining the water supply of the United States, including the investigation of underground currents and artesian wells in the arid and semiarid sections.'

  4. Time-series studies of drainage pattern and morphological features along the Leitha river (Eastern Austria)

    Zámolyi, A.; Draganits, E.; Doneus, M.; Fera, M.; Griebl, M.


    Geomorphologic mapping and drainage network analysis was conducted in the Southern Vienna Basin on the Leitha and Fischa rivers. The study area belongs to an active pull-apart basin between the Eastern Alps and the Carpathians that started to subside in Karpatian times (~ 17 Ma), but with still active faults, proven by fault scarps and earth quakes. The investigated rivers are important tributaries to the Danube river and run through a region that has been subject to settlement since Neoltihic times. Thus, interaction between land use, settlement pattern and river dynamics can be studied. Several datasets are integrated to perform a comprehensive overview of geomorphological, as well as river dynamic changes in the landscape. During an earlier stage of this investigation a map of paleochannel distribution including the location and shape of the paleochannels was extracted from color-infrared and RGB digital orthophotos. Based on this map the location, character and shape of palaeomeanders is studied on different georeferenced historic maps (Timár et al., 2006; Biszak et al., 2007) in order to derive a time-series study. The paleochannels extracted from the digital orthophotos show a good coincidence with the depicted rivers on the historic maps. This partly allows quite well constrained age estimates of the paleochannel sections. The investigated maps are the Walter maps, the First, Second and Third Military Survey of the Habsburg/Austro-Hungarian Empire. Mapping of the Walter maps was conducted 1754-56 (Ulbrich, 1952), the First, Second and Third Military Surveys were mapped in this area in the time-span of 1782-1785, 1819-1869, and 1872-1873, respectively (Kretschmer et al., 2004). This sequence of georeferenced historical maps allows to study only a very short time-span (1755 - 1873) compared to the geological time scale. However, the characteristics of river dynamics special for the study area can be derived and, considering certain assumptions, extrapolated

  5. Pattern specificity in the effect of prior Δƒ on auditory stream segregation.

    Snyder, Joel S; Weintraub, David M


    During repeating sequences of low (A) and high (B) tones, perception of two separate streams ("streaming") increases with greater frequency separation (Δƒ) between the A and B tones; in contrast, a prior context with large Δƒ results in less streaming during a subsequent test pattern. The purpose of the present study was to investigate what aspects of the context pattern are necessary for this context effect to occur. Simply changing the B-tone frequency without an alternating A tone present was not sufficient to cause the effect of prior Δƒ, but rather a melodic change between A and B tones was necessary. We further investigated the extent to which the context and test patterns needed to have similar rhythms (xxx-xxx-) and melodies (up-down-flat-up-down), and found that a maximal prior-Δƒ effect occurred when the rhythmic patterns of the context and test were similar, regardless of the melodic structure. Thus, the effect of prior Δƒ on streaming depended on the presence of (1) at least one melodic change in the context, and (2) similar rhythmic patterns in the context and test.

  6. Shared and unique patterns of phenotypic diversification along a stream gradient in two congeneric species

    Jourdan, Jonas; Krause, Sarah T.; Lazar, V. Max; Zimmer, Claudia; Sommer-Trembo, Carolin; Arias-Rodriguez, Lenin; Klaus, Sebastian; Riesch, Rüdiger; Plath, Martin


    Stream ecosystems show gradual variation of various selection factors, which can result in a zonation of species distributions and gradient evolution of morphological and life-history traits within species. Identifying the selective agents underlying such phenotypic evolution is challenging as different species could show shared and/or unique (species-specific) responses to components of the river gradient. We studied a stream gradient inhabited by two mosquitofishes (genus Gambusia) in the Río Grijalva basin in southern Mexico and found a patchy distribution pattern of both congeners along a stretch of 100 km, whereby one species was usually dominant at a given site. We uncovered both shared and unique patterns of diversification: some components of the stream gradient, including differences in piscine predation pressure, drove shared patterns of phenotypic divergence, especially in females. Other components of the gradient, particularly abiotic factors (max. annual temperature and temperature range) resulted in unique patterns of divergence, especially in males. Our study highlights the complexity of selective regimes in stream ecosystems. It exemplifies that even closely related, congeneric species can respond in unique ways to the same components of the river gradient and shows how both sexes can exhibit quite different patterns of divergence in multivariate phenotypic character suites.

  7. Agro-Economic Design of Cropping Pattern in Hendijan Irrigation and Drainage Network with Emphasis on Water Resources

    A Madeh Khaksar


    Full Text Available Recently, design of cropping pattern based on water resources is getting a high priority. This scheme is complicated, and affected by multiple factors. For investigation, designer must gather a huge data, and classify them. The method of processing and analyzing of the information is important. The method of linear programming based on Lingo software for Hendijan irrigation and drainage network was used. On the basis of water resources situation, physical limitations, ecology and economical parameters, hydromodule was determined. The model with initial data for crop pattern is performed by software to produce projected hydromodule. In this survey, sensitivity analysis on water cost was conducted. Result showed that by increasing water cost and rotation intensity, revenue for each consumption water unit was decreased. The maximum benefit for all available conditions of water on the case of non intensity would be 140 percent, for 3% of crops. The maximum benefit was 133346682 Rls per hectare based on water availability for 2006.

  8. Abandoned mine drainage in the Swatara Creek Basin, southern anthracite coalfield, Pennsylvania, USA: 1. stream quality trends coinciding with the return of fish

    Cravotta, Charles A.; Brightbill, Robin A.; Langland, Michael J.


    Acidic mine drainage (AMD) from legacy anthracite mines has contaminated Swatara Creek in eastern Pennsylvania. Intermittently collected base-flow data for 1959–1986 indicate that fish were absent immediately downstream from the mined area where pH ranged from 3.5 to 7.2 and concentrations of sulfate, dissolved iron, and dissolved aluminum were as high as 250, 2.0, and 4.7 mg/L, respectively. However, in the 1990s, fish returned to upper Swatara Creek, coinciding with the implementation of AMD treatment (limestone drains, limestone diversion wells, limestone sand, constructed wetlands) in the watershed. During 1996–2006, as many as 25 species of fish were identified in the reach downstream from the mined area, with base-flow pH from 5.8 to 7.6 and concentrations of sulfate, dissolved iron, and dissolved aluminum as high as 120, 1.2, and 0.43 mg/L, respectively. Several of the fish taxa are intolerant of pollution and low pH, such as river chub (Nocomis icropogon) and longnose dace (Rhinichthys cataractae). Cold-water species such as brook trout (Salvelinus fontinalis) and warm-water species such as rock bass (Ambloplites rupestris) varied in predominance depending on stream flow and stream temperature. Storm flow data for 1996–2007 indicated pH, alkalinity, and sulfate concentrations decreased as the stream flow and associated storm-runoff component increased, whereas iron and other metal concentrations were poorly correlated with stream flow because of hysteresis effects (greater metal concentrations during rising stage than falling stage). Prior to 1999, pH\\5.0 was recorded during several storm events; however, since the implementation of AMD treatments, pH has been maintained near neutral. Flow-adjusted trends for1997–2006 indicated significant increases in calcium; decreases in hydrogen ion, dissolved aluminum, dissolved and total manganese, and total iron; and no change in sulfate or dissolved iron in Swatara Creek immediately downstream from the


    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...... Instruction. The aim of the model is to provide both a concrete and comprehensible design toolkit for adopting and implementing educational technologies in higher science teaching practice and at the same time comply with diverse ambitions. As opposed to the above-mentioned feedback strategies, the STREAM...

  10. The Relative Effects of Hydrology, Ecology, and Climate on Temporal Trends and Spatial Patterns of Stream Nitrate Concentrations in the Catskill Mountains, New York, USA

    Burns, D. A.; Lovett, G. M.; Murdoch, P. S.


    The Catskill Mountains of New York receive 10 to 15 kg ha-1 yr-1 of nitrogen (N) in atmospheric deposition, among the highest rates in eastern North America. Consequently, streams in the Catskills have relatively high nitrate (NO3-) concentrations (mean of stream surveys = 20 to 30 μ mol L-1 at baseflow), which contribute to chronic and episodic stream acidification. Stream chemistry monitoring in the 1980s showed an increasing trend in NO3- concentrations that was attributed to N saturation, a condition whereby continued high rates of atmospheric N deposition in combination with a maturing forest result in gradually decreasing ecosystem N retention. This increasing trend reversed itself during the early 1990s, a pattern that was partially attributed to an intense region-wide soil freezing event in December 1989. Stream NO3- concentrations remained relatively low at long-term monitoring sites from 1992-03 despite relatively constant atmospheric N deposition rates from the 1980s through 2003, suggesting that a simple interpretation of the N saturation model is not valid on decadal time scales. The discovery of groundwater seeps with relatively high NO3- concentrations in the 1990s led to a hypothesis that the presence of seeps in the Catskills may be controlling spatial variability in stream NO3- concentrations, which range from near 0 to about 50 μ mol L-1 at baseflow. Subsequent research indicated these variations in stream NO3- concentrations are likely controlled by variations in tree species dominance. Nitrate concentrations in drainage waters are highest in stands of sugar maple and yellow birch and lowest in red oak and hemlock stands. One study, however, showed that NO3- concentrations in shallow groundwater were correlated with a topographic index that is a surrogate for soil moisture suggesting that covariance of tree species and soil moisture may amplify the apparent differences in NO3- concentrations previously attributed solely to differences in tree

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

    Frost, Thomas P.; Box, Stephen E.


    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.

  12. Streaming driven by sessile microbubbles: Explaining flow patterns and frequency response

    Rallabandi, Bhargav; Wang, Cheng; Guo, Lin; Hilgenfeldt, Sascha


    Ultrasound excitation of bubbles drives powerful steady streaming flows which have found widespread applications in microfluidics, where bubbles are typically of semicircular cross section and attached to walls of the device (sessile). While bubble-driven streaming in bulk fluid is well understood, this practically relevant case presents additional complexity introduced by the wall and contact lines. We develop an asymptotic theory that takes into account the presence of the wall as well as the oscillation dynamics of the bubble, providing a complete description of the streaming flow as a function only of the driving frequency, the bubble size, and the physical properties of the fluid. We show that the coupling between different bubble oscillation modes sustains the experimentally observed streaming flow vortex pattern over a broad range of frequencies, greatly exceeding the widths of individual mode resonances. Above a threshold frequency, we predict, and observe in experiment, reversal of the flow direction. Our analytical theory can be used to guide the design of microfluidic devices, both in situations where robust flow patterns insensitive to parameter changes are desired (e.g. lab-on-a-chip sorters), and in cases where intentional modulation of the flow field appearance is key (e.g. efficient mixers). Current address: Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology.

  13. Sorption of trace metals to an aluminum precipitate in a stream receiving acid rock-drainage; Snake River, Summit County, Colorado

    Munk, L.A.; Faure, G.; Pride, D.E. [Ohio State University, Columbus, OH (United States). Dept. of Geological Sciences; Bigham, J.M. [Ohio State University, Columbus, OH (United States). School of Natural Resources


    The quality of water in streams that are contaminated by acid drainage from mines and from the weathering of mineralized rocks improves as the water flows downstream. The purpose of this study was to investigate the geochemical processes that occur in one such stream and to determine the fate of the trace metals that are removed from the water. The stream chosen for this purpose was the Snake River, Summit County, Colorado, which is affected by natural acid rock-drainage (ARD) containing SO{sub 4}, Al, Fe, and various trace elements such as Zn, Cu, Pb, Ni, and others. Most of the Fe in the Snake River is removed from solution by the oxidation of Fe{sup 2+} to Fe{sup 3+} and the subsequent precipitation of Fe-oxyhydroxides that form a massive ferricrete deposit near the springs that feed the river. Further downstream, the Snake River (pH = 3.0) mixes with water from Deer Creek (pH = 7.0) thereby increasing its pH to 6.3 and causing SO{sub 4}-rich precipitates of Al-oxyhydroxide to form. The precipitates and associated organic C complexes sorb trace metals from the water and thus have high concentrations of certain elements, including Zn (540-11,400 ppm), Cu (34-221 ppm), Pb (90-340 ppm), and Ni (11-197 ppm). The concentrations of these elements in the precipitates that coat the streambed rise steeply in the zone of mixing and then decline downstream. The trace element concentrations of the water in the mixing zone at the confluence with Deer Creek decrease by 75% or more and are up to 3 orders of magnitude lower than those of the precipitates. Sorption curves for Zn, Cu, Pb, Ni, and SO{sub 4} were derived by stepwise neutralization of a sample of Snake River water (collected above the confluence with Deer Creek) and indicate that the trace metals are sorbed preferentially with increasing pH in the general order Pb, Cu, Zn, and Ni. Sulfate is removed between pH 4 and 5 to form an Al-hydroxysulfate and/or by sorption to microcrystalline gibbsite. The sorption data

  14. Drainage Network and Lineament Analysis: An Approach for Potwar Plateau (Northern Pakistan)

    Faisal SHAHZAD; Syed Amer MAHMOOD; Richard GLOAGUEN


    Drainage responds rapidly to tectonic changes and thus it is a potential parameter for tectonogeomorphological analysis. Drainage network of Potwar is a good geological record of movement, displacements, regional uplifts and erosion of the tectonic units. This study focuses on utilizing drainage network extracted from Shuttle Radar Digital Elevation Data (SRTM-DEM) in order to constrain the structure of the Potwar Plateau. SWAN syncline divides Potwar into northern Potwar deformed zone (NPDZ) and southern Potwar platform zone (SPPZ). We extracted the drainage network from DEM and analyzed 112 streams using stream power law. Spatial distribution of concavity and steepness indices were used to prepare uplift rate map for the area. DEM was further utilized to extract lineaments to study the mutual relationship between lineaments and drainage patterns. We compared the local correlation between the extracted lineaments and drainage network of the area that gives us quantitative information and shows promising prospects. The streams in the NPDZ indicate high steepness values as compared to the streams in the SPPZ. The spatial distribution of geomorphic parameters and uplift rates suggest the distinctive deformation among eastern, central and western parts. The local correlation between drainage network and lineaments from DEM is strongly positive in the area within 1 km of radius.

  15. Impact of land drainage on peatland hydrology.

    Holden, J; Evans, M G; Burt, T P; Horton, M


    There is a long history of drainage of blanket peat but few studies of the long-term hydrological impact of drainage. This paper aims to test differences in runoff production processes between intact and drained blanket peat catchments and determine whether there have been any long-term changes in stream flow since drainage occurred. Hillslope runoff processes and stream discharge were measured in four blanket peat catchments. Two catchments were drained with open-cut ditches in the 1950s. Ditching originally resulted in shorter lag times and flashier storm hydrographs but no change in the annual catchment runoff efficiency. In the period between 2002 and 2004, the hydrographs in the drained catchments, while still flashy, were less sensitive to rainfall than in the 1950s and the runoff efficiency had significantly increased. Drains resulted in a distinctive spatial pattern of runoff production across the slopes. Overland flow was significantly lower in the drained catchments where throughflow was more dominant. In the intact peatlands, matrix throughflow produced by peat layers below 10 cm was rare and produced structure could explain the long-term changes in river flow, which are in addition to those occurring in the immediate aftermath of peatland drainage.

  16. Validation of the stream function method used for reconstruction of experimental ionospheric convection patterns

    P.L. Israelevich

    Full Text Available In this study we test a stream function method suggested by Israelevich and Ershkovich for instantaneous reconstruction of global, high-latitude ionospheric convection patterns from a limited set of experimental observations, namely, from the electric field or ion drift velocity vector measurements taken along two polar satellite orbits only. These two satellite passes subdivide the polar cap into several adjacent areas. Measured electric fields or ion drifts can be considered as boundary conditions (together with the zero electric potential condition at the low-latitude boundary for those areas, and the entire ionospheric convection pattern can be reconstructed as a solution of the boundary value problem for the stream function without any preliminary information on ionospheric conductivities. In order to validate the stream function method, we utilized the IZMIRAN electrodynamic model (IZMEM recently calibrated by the DMSP ionospheric electrostatic potential observations. For the sake of simplicity, we took the modeled electric fields along the noon-midnight and dawn-dusk meridians as the boundary conditions. Then, the solution(s of the boundary value problem (i.e., a reconstructed potential distribution over the entire polar region is compared with the original IZMEM/DMSP electric potential distribution(s, as well as with the various cross cuts of the polar cap. It is found that reconstructed convection patterns are in good agreement with the original modelled patterns in both the northern and southern polar caps. The analysis is carried out for the winter and summer conditions, as well as for a number of configurations of the interplanetary magnetic field.

    Key words: Ionosphere (electric fields and currents; plasma convection; modelling and forecasting

  17. Monitoring, field experiments, and geochemical modeling of Fe(II) oxidation kinetics in a stream dominated by net-alkaline coal-mine drainage, Pennsylvania, USA

    Cravotta, Charles A.


    Watershed-scale monitoring, field aeration experiments, and geochemical equilibrium and kinetic modeling were conducted to evaluate interdependent changes in pH, dissolved CO2, O2, and Fe(II) concentrations that typically take place downstream of net-alkaline, circumneutral coal-mine drainage (CMD) outfalls and during aerobic treatment of such CMD. The kinetic modeling approach, using PHREEQC, accurately simulates observed variations in pH, Fe(II) oxidation, alkalinity consumption, and associated dissolved gas concentrations during transport downstream of the CMD outfalls (natural attenuation) and during 6-h batch aeration tests on the CMD using bubble diffusers (enhanced attenuation). The batch aeration experiments demonstrated that aeration promoted CO2 outgassing, thereby increasing pH and the rate of Fe(II) oxidation. The rate of Fe(II) oxidation was accurately estimated by the abiotic homogeneous oxidation rate law −d[Fe(II)]/dt = k1·[O2]·[H+]−2·[Fe(II)] that indicates an increase in pH by 1 unit at pH 5–8 and at constant dissolved O2 (DO) concentration results in a 100-fold increase in the rate of Fe(II) oxidation. Adjusting for sample temperature, a narrow range of values for the apparent homogeneous Fe(II) oxidation rate constant (k1′) of 0.5–1.7 times the reference value of k1 = 3 × 10−12 mol/L/min (for pH 5–8 and 20 °C), reported by Stumm and Morgan (1996), was indicated by the calibrated models for the 5-km stream reach below the CMD outfalls and the aerated CMD. The rates of CO2 outgassing and O2ingassing in the model were estimated with first-order asymptotic functions, whereby the driving force is the gradient of the dissolved gas concentration relative to equilibrium with the ambient atmosphere. Although the progressive increase in DO concentration to saturation could be accurately modeled as a kinetic function for the conditions evaluated, the simulation of DO as an instantaneous equilibrium process did not affect the

  18. Spatial patterns of water-dispersed seed deposition along stream riparian gradients.

    Fraaije, Rob G A; Moinier, Sophie; van Gogh, Iris; Timmers, Robert; van Deelen, Joost J; Verhoeven, Jos T A; Soons, Merel B


    Riparian ecosystems along streams naturally harbour a high plant diversity with many increasingly endangered species. In our current heavily modified and fragmented catchments, many of these species are sensitive to dispersal limitation. Better understanding of riparian plant dispersal pathways is required to predict species (re-)colonization potential and improve success rates of stream and riparian zone conservation and restoration. Dispersal by water (hydrochory) is an important mechanism for longitudinal and lateral dispersal of riparian species. Crucially for recruitment potential, it also influences the elevation along the riparian hydrological gradient where seeds become deposited. Due to the complex interplay between abiotic and biotic factors, however, it remains unclear how exactly patterns in seed deposition are formed. We compared hydrochorous and non-hydrochorous seed deposition, and quantified patterns of seed deposition along the bare substrate of newly created stream riparian gradients. Water levels were monitored and seed deposition was measured with seed traps along the full range of riparian hydrological conditions (from permanently flooded to never flooded). Average seed numbers and species richness were significantly higher in flooded than in non-flooded seed traps (5.7 and 1.5 times higher, respectively). Community-weighted trait means indicated that typically water-dispersed seeds were more dominant in flooded than in non-flooded seed traps and gradually decreased in concentration from the channel to the upland. Moreover, highly buoyant seeds accumulated at the average water line, and clear elevational sorting of non-buoyant seeds occurred within the floodplain. These results establish a critical role of flooding in shaping patterns of seed deposition along the riparian gradient, delivering many seeds of typical riparian species to riparian zones and depositing them at species-specific elevations as influenced by seed traits, suggesting

  19. Geochemical Characterization of Mine Waste, Mine Drainage, and Stream Sediments at the Pike Hill Copper Mine Superfund Site, Orange County, Vermont

    Piatak, Nadine M.; Seal, Robert R.; Hammarstrom, Jane M.; Kiah, Richard G.; Deacon, Jeffrey R.; Adams, Monique; Anthony, Michael W.; Briggs, Paul H.; Jackson, John C.


    The Pike Hill Copper Mine Superfund Site in the Vermont copper belt consists of the abandoned Smith, Eureka, and Union mines, all of which exploited Besshi-type massive sulfide deposits. The site was listed on the U.S. Environmental Protection Agency (USEPA) National Priorities List in 2004 due to aquatic ecosystem impacts. This study was intended to be a precursor to a formal remedial investigation by the USEPA, and it focused on the characterization of mine waste, mine drainage, and stream sediments. A related study investigated the effects of the mine drainage on downstream surface waters. The potential for mine waste and drainage to have an adverse impact on aquatic ecosystems, on drinking- water supplies, and to human health was assessed on the basis of mineralogy, chemical concentrations, acid generation, and potential for metals to be leached from mine waste and soils. The results were compared to those from analyses of other Vermont copper belt Superfund sites, the Elizabeth Mine and Ely Copper Mine, to evaluate if the waste material at the Pike Hill Copper Mine was sufficiently similar to that of the other mine sites that USEPA can streamline the evaluation of remediation technologies. Mine-waste samples consisted of oxidized and unoxidized sulfidic ore and waste rock, and flotation-mill tailings. These samples contained as much as 16 weight percent sulfides that included chalcopyrite, pyrite, pyrrhotite, and sphalerite. During oxidation, sulfides weather and may release potentially toxic trace elements and may produce acid. In addition, soluble efflorescent sulfate salts were identified at the mines; during rain events, the dissolution of these salts contributes acid and metals to receiving waters. Mine waste contained concentrations of cadmium, copper, and iron that exceeded USEPA Preliminary Remediation Goals. The concentrations of selenium in mine waste were higher than the average composition of eastern United States soils. Most mine waste was


    Ionut Minea


    Full Text Available ABSTRACT. – Patterns utilized in the simulation of underground water flow and the transportation of pollutants in the Bahlui drainage basin. In the actual context of accelerate economic development, the excessive exploatation of water resources from the underground and the contamination of these with different water pollutants has become a major problem which has enetered the attention of many researchers. For the evaluation of an underground water flow and pollutants transport sistem we have chosen the package of programs MODFLOW which includes a whole series of applications,such as MOC3D, MT3D, MT3DMS, PEST, UCODE, PMPATH, which allow simulations and multiple recalibrations of the capacity of recharging of the aquifers, the flowing of the water towards wells and drillings the transport of a pollutant agent in the underground or the evaluation of the exchange of water between the hidrographic network and aquifers. The sistem targets both the evaluation of the modelation of the underground flowing and the simulation of a punctual polluation of the canvas of groundwater scenery, in the meadow of the river Bahlui, west from Letcani village.

  1. Controls of catchments` sub-storage contributions to dynamic water quality patterns in the stream network

    Schuetz, Tobias; Maike Hegenauer, Anja


    Water quality is usually observed either continuously at a few stations within a catchment or with few snapshot sampling campaigns throughout the whole stream network. Although we know that the depletion of catchment sub-storages can vary throughout the stream network according to their actual water content (spatial variability of actual storage conditions can be caused amongst others by unevenly distributed rainfall, storage size or spatial differences in soil characteristics and land use), we know little about the impact of this process on spatial water quality patterns. For summer low flow recession periods, when stream water composition can be crucial for aquatic ecosystem conditions and the exceedance of water quality thresholds, knowledge on the controls of the dynamic interplay of catchment storages and stream water composition might improve water quality management and the implementation of corresponding mitigation measures. We studied this process throughout the stream network of a first-order agricultural headwater catchment in south-western Germany during two summer low flow recession periods. The underlying geology of the study area is a deep layer of aeolian loess, whilst the dominating soil is a silty calcaric regosol with gleizations in the colluvium. The land use in the catchment is dominated by viniculture (63 %) and arable crops (18 %). Due to the dense drainpipe network within the catchment we could identify 12 sub-catchments contributing during summer low flow recession periods to total stream discharge. We continuously observed discharge, electrical conductivity and water temperatures for 8 of the sub-catchments and at the catchment outlet. This data set was accomplished by 10 snapshot campaigns where we sampled for water temperatures, electrical conductivity, major ions, pH and O2 throughout the stream network. Using either discharge concentration relationships or time dependent functions, we derived continuous export rates for all measures in

  2. WorkStream-- A Design Pattern for Multicore-Enabled Finite Element Computations

    Turcksin, Bruno


    Many operations that need to be performed in modern finite element codes can be described as an operation that needs to be done independently on every cell, followed by a reduction of these local results into a global data structure. For example, matrix assembly, estimating discretization errors, or converting nodal values into data structures that can be output in visualization file formats all fall into this class of operations. Using this realization, we identify a software design pattern that we callWorkStream and that can be used to model such operations and enables the use of multicore shared memory parallel processing. We also describe in detail how this design pattern can be efficiently implemented, and we provide numerical scalability results from its use in the DEAL.II software library.

  3. Synaptic signal streams generated by ex vivo neuronal networks contain non-random, complex patterns.

    Lee, Sangmook; Zemianek, Jill M; Shultz, Abraham; Vo, Anh; Maron, Ben Y; Therrien, Mikaela; Courtright, Christina; Guaraldi, Mary; Yanco, Holly A; Shea, Thomas B


    Cultured embryonic neurons develop functional networks that transmit synaptic signals over multiple sequentially connected neurons as revealed by multi-electrode arrays (MEAs) embedded within the culture dish. Signal streams of ex vivo networks contain spikes and bursts of varying amplitude and duration. Despite the random interactions inherent in dissociated cultures, neurons are capable of establishing functional ex vivo networks that transmit signals among synaptically connected neurons, undergo developmental maturation, and respond to exogenous stimulation by alterations in signal patterns. These characteristics indicate that a considerable degree of organization is an inherent property of neurons. We demonstrate herein that (1) certain signal types occur more frequently than others, (2) the predominant signal types change during and following maturation, (3) signal predominance is dependent upon inhibitory activity, and (4) certain signals preferentially follow others in a non-reciprocal manner. These findings indicate that the elaboration of complex signal streams comprised of a non-random distribution of signal patterns is an emergent property of ex vivo neuronal networks.

  4. A low cost sensor network approach to investigate spatio-temporal patterns of stream temperatures and electrical conductivity

    Lieder, Ernestine; Weiler, Markus; Blume, Theresa


    Understanding water and energy fluxes at the stream and catchment scale remains a challenging task. Within the CAOS-project-framework it is our aim to investigate spatiotemporal patterns of stream temperature and to deduce understanding about the underlying hydrological system. A low cost sensor network was installed in summer 2015 to monitor stream temperature and EC patterns in time and space. 90 HOBO temperature sensors, which were modified to additionally measure EC, were installed at 30 confluences across the Attert catchment (288 km²) in Luxembourg. The design of the sensor network allows for the investigation of three research questions: a) spatial patterns of stream temperatures and EC and their dynamics across the region b) estimation of relative streamflow contributions and their temporal dynamics by using simple mixing models and c) estimation of heat transport. The data will thus provide valuable insight in runoff contributions from different sub-catchments, and a combined analysis with distributed measurements of soil moisture and shallow groundwater will improve our process understanding by linking hillslope scale processes with stream responses. First results indicate that streams in different geologies show distinct temperature and EC patterns throughout the observation period. Differences are also found with respect to temporal dynamics both for longer periods as well as diurnal fluctuations. These differences are likely to be caused by differences in flow paths on the one hand (e.g. amount of groundwater contribution) and exposure to direct radiation on the other hand.

  5. The use of multi-channel ground penetrating radar and stream monitoring to investigate the seasonal evolution of englacial and subglacial drainage systems at the terminus of Exit Glacier, Alaska

    Kilgore, Susan Marlena

    Concerns regarding the issue of climate change and, in particular, the rapid retreat of glaciers around the world, have placed great importance on glacial monitoring. Some of the methods most commonly used to observe glacial change---direct mass balance measurements and remote sensing---provide valuable information about glacier change. However, these methods do not address the englacial and subglacial environments. Surface meltwater that enters englacial and subglacial hydrological networks can contribute to acceleration of ice flow, increased calving on marine-terminating glaciers, surges or outburst floods, and greater overall ablation rates. Because subsurface drainage systems often freeze during the winter and re-form each summer, examining the seasonal evolution of these networks is crucial for assessing the impact that internal drainage may have on the behavior of a glacier each year. The goal of this study is to determine the role englacial and subglacial drainage system evolution plays in influencing summer ablation and discharge at the terminus of Exit Glacier, a small valley glacier located in South-central Alaska. During the summers of 2010 and 2011, we used ground-penetrating radar (GPR) to locate internal drainage features on the lower 100 meters of the glacier. GPR surveys were conducted in June and August of each year in an effort to observe the evolution of the drainage systems over the course of an ablation season. Three antenna frequencies---250, 500, and 800 MHz---were used on a dual frequency GPR so that various resolutions and depths in the ice could be viewed simultaneously. Stream monitoring was conducted to document discharge in the proglacial stream throughout the 2011 season. These data were compared with weather records to differentiate noticeable meltwater releases from precipitation events. Additionally, morphological changes in the glacier were observed through photographic documentation. Throughout the observation period, significant

  6. Movement patterns of stream-dwelling fishes from Mata Atlântica, Southeast Brazil.

    Mazzoni, Rosana; Iglesias-Rios, Ricardo


    The identification of mechanisms of spatial-temporal variation, obtained from the quantification of natural populations, is a central topic of ecological research. Despite its importance to life-history theory, as well as to conservation and management of natural populations, no studies concerning movement patterns and home range of small stream-dwelling fishes from Brazilian rain forests are known. In the present study we aimed to describe the longitudinal pattern of long distance movement as well as local patterns of short movement (daily home-range) of fishes from a Mata Atlântica stream from Southeast Brazil. We gathered information about movement dynamic in order to discuss the relationship between swimming ability, fish morphology and home range. Long distance movement data were obtained in a mark-recapture experiment held in the field between June and September - 2008, on five sites along the Ubatiba stream. For this study, we had one day to mark fishes, on June-19, and 14 events for recapture. Considering the ten species that inhabit the study area, our study showed that four species: Astyanax janeiroensis, Astyanax hastatus, Parotocinclus maculicauda and Pimelodella lateristriga, moved at least 6 000m in 60 days. The other six species did not present long distance movements, as they were recaptured in the same site 90 days after being marked. For short distance study, movement data were obtained in one mark-recapture experiment held in a 100m long site subdivided into five 20m stretches where fishes were marked with different elastomer colours. We marked 583 specimens that after recapture showed two groups of different movement patterns. The first group was called "Long Movement Group" and the second one was called "Short Movement Group". The Long Movement Group showed, on average, 89.8% of moving fishes and 10.2% of non moving fishes, against 21.3% and 78.7%, respectively, for the Short Movement Group. It was concluded that fish movement could explain

  7. The ecology of methane in streams and rivers: Patterns, controls, and global significance

    Stanley, Emily H.; Casson, Nora J.; Christel, Samuel T.; Crawford, John T.; Loken, Luke; Oliver, Samantha K.


    Streams and rivers can substantially modify organic carbon (OC) inputs from terrestrial landscapes, and much of this processing is the result of microbial respiration. While carbon dioxide (CO2) is the major end-product of ecosystem respiration, methane (CH4) is also present in many fluvial environments even though methanogenesis typically requires anoxic conditions that may be scarce in these systems. Given recent recognition of the pervasiveness of this greenhouse gas in streams and rivers, we synthesized existing research and data to identify patterns and drivers of CH4, knowledge gaps, and research opportunities. This included examining the history of lotic CH4 research, creating a database of concentrations and fluxes (MethDB) to generate a global-scale estimate of fluvial CH4 efflux, and developing a conceptual framework and using this framework to consider how human activities may modify fluvial CH4 dynamics. Current understanding of CH4 in streams and rivers has been strongly influenced by goals of understanding OC processing and quantifying the contribution of CH4 to ecosystem C fluxes. Less effort has been directed towards investigating processes that dictate in situ CH4 production and loss. CH4 makes a meager contribution to watershed or landscape C budgets, but streams and rivers are often significant CH4 sources to the atmosphere across these same spatial extents. Most fluvial systems are supersaturated with CH4 and we estimate an annual global emission of 26.8 Tg CH4, equivalent to ~15-40% of wetland and lake effluxes, respectively. Less clear is the role of CH4 oxidation, methanogenesis, and total anaerobic respiration to whole ecosystem production and respiration. Controls on CH4 generation and persistence can be viewed in terms of proximate controls that influence methanogenesis (organic matter, temperature, alternative electron acceptors, nutrients) and distal geomorphic and hydrologic drivers. Multiple controls combined with its

  8. A GIS-based approach in drainage morphometric analysis of Kanhar River Basin, India

    Rai, Praveen Kumar; Mohan, Kshitij; Mishra, Sameer; Ahmad, Aariz; Mishra, Varun Narayan


    The study indicates that analysis of morphometric parameters with the help of geographic information system (GIS) would prove a viable method of characterizing the hydrological response behaviour of the watershed. It is also well observed that remote sensing satellite data is emerging as the most effective, time saving and accurate technique for morphometric analysis of a basin. This technique is found relevant for the extraction of river basin and its stream networks through ASTER (DEM) in conjunction with remote sensing satellite data (Landsat etm+, 2013 and georeferenced survey of Indian toposheet, 1972). In this study, Kanhar basin a tributaries of Son River has been selected for detailed morphometric analysis. Seven sub-watersheds are also delineated within this basin to calculate the selected morphometric parameters. Morphometric parameters viz; stream order, stream length, bifurcation ratio, drainage density, stream frequency, form factor, circulatory ratio, etc., are calculated. The drainage area of the basin is 5,654 km2 and shows sub-dendritic to dendritic drainage pattern. The stream order of the basin is mainly controlled by physiographic and lithological conditions of the area. The study area is designated as seventh-order basin with the drainage density value being as 1.72 km/km2. The increase in stream length ratio from lower to higher order shows that the study area has reached a mature geomorphic stage.

  9. Parallel streams versus integrated timing in multilimb pattern generation: A test of Korte's Third Law.

    Jagacinski, Richard J; Rizzi, Emanuele; Kim, Tae Hoon; Lavender, Steven A; Speller, Lassiter F; Klapp, Stuart T


    Skilled drummers performed a 4:3:2 polyrhythm with 2 hands and 1 foot. For each pair of limbs patterns of temporal covariation were used to infer relatively independent parallel streams versus integrated timing relationships. Parallel timing was more prevalent between hand and foot than between the 2 hands, and parallel timing generally increased with tapping rate. Different combinations of integrated and parallel timing were found among the 3 limbs. A second experiment used a wider range of tapping rates and explored 3:2 tapping with 2 hands, 2 feet, or hand and foot. The latter 2 limb pairs resulted in greater prevalence of parallel timing. These results can be interpreted in terms of a Gestalt principle of grouping known as Korte's Third Law, which can be extended from the perceptual domain to the perceptual-motor domain. This principle indicates that perceived velocity is a key factor in determining whether a sequence of events is represented as a single integrated pattern or as multiple parallel patterns. The present results put disparate previous findings on bimanual polyrhythmic tapping and rhythmic aspects of the golf swing under a common theoretical perspective. (PsycINFO Database Record

  10. Spatial and temporal patterns of micropollutants in streams and effluent of 24 WWTPs across Switzerland

    Schönenberger, Urs; Spycher, Barbara; Kistler, David; Burdon, Frank; Reyes, Marta; Eggen, Rik; Joss, Adriano; Singer, Heinz; Stamm, Christian


    Treated municipal wastewater is an important source of micropollutants entering the environment. Micropollutants are a diverse range of chemicals of which concentrations vary strongly in space and time. To better quantitatively understand the spatio-temporal patterns of micropollutants in streams, we compared upstream and downstream locations at 24 wastewater treatment plants (WWTPs) across the Swiss Plateau and Jura regions. Each site represents the most upstream treatment plant in the corresponding catchment. In 2013, a broad analytical screening was applied to samples collected at 12 sites during winter (January) and summer conditions (June). Based in these results, the bi-monthly samples obtained in 2014 at 12 additional sites were analysed for a group of approximately 60 selected organic micropollutants. The screening results demonstrate that generally, pharmaceuticals, artificial sweeteners and corrosion inhibitors make up the largest share of the organic micropollutants in wastewater. Pesticides including biocides and plant protection products are also regularly found, but at lower concentrations. The opposite holds true for the concentration variability: pesticides vary the most across time and space, while pharmaceuticals exhibit more stable concentrations. Heavy metals fluctuate to a similar degree as pharmaceuticals. Principal component analyses suggest that pesticide and pharmaceutical levels at both upstream locations and in the wastewater vary independently of each other. At the upstream locations, the pesticide levels increased with the proportion of arable land in the watershed, whilst decreasing with greater cover of pasture and forest. Interestingly, the same patterns hold true for the composition of wastewater when considering land use in the catchments of the WWTPs. This suggests that pesticide-intensive agricultural crops not only impact surface water quality via diffuse pollution but also increase levels of pesticides in wastewater discharged

  11. Effects of exposure to agricultural drainage ditch water on survivorship, distribution, and abundnance of riffle beetles (Coleoptera: Elmidae) in headwater streams of the Cedar Creek watershed, Indiana

    Riffle Beetles (Coleoptera: Elmidae) require very good water quality, mature streams with riffle habitat, and high dissolved oxygen content. As such, they prove to be good indicators of ecological health in agricultural headwater streams. We conducted static renewal aquatic bioassays using water fro...

  12. On the dynamics of stream piracy

    Goren, L.; Willett, S. D.


    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.

  13. Ecology and management of agricultural drainage ditches: a literature review

    Agricultural drainage ditches are headwater streams that have been modified or constructed for agricultural drainage, and are often used in conjunction with tile drains. These modified streams are a common landscape feature in Ohio, and constitute 25% of stream habitat within the state. Management o...

  14. Preliminary results from agricultural drainage water management CIG projects on Ohio

    Field demonstrations were monitored to compare the crop yields, drainage discharge, and nutrient loadings to streams from managed and unmanaged subsurface drainage systems. Paired drainage systems within the same field, under similar soil, area, cropping, and management conditions, were identified. ...

  15. Coalescence patterns of endemic Tibetan species of stream salamanders (Hynobiidae: Batrachuperus).

    Lu, Bin; Zheng, Yuchi; Murphy, Robert W; Zeng, Xiaomao


    Orogenesis of topographically diverse montane regions often drives complex evolutionary histories of species. The extensive biodiversity of the eastern edge of the Tibetan Plateau, which gradually decreases eastwardly, facilitates a comparison of historical patterns. We use coalescence methods to compare species of stream salamanders (Batrachuperus) that occur at high and low elevations. Coalescent simulations reveal that closely related species are likely to have been influenced by different drivers of diversification. Species living in the western high-elevation region with its northsouth extending mountains appear to have experienced colonization via dispersal followed by isolation and divergence. In contrast, species on the eastern low-elevation region, which has many discontinuous mountain ranges, appear to have experienced fragmentation, sometimes staged, of wide-ranging ancestral populations. The two groups of species appear to have been affected differently by glaciation. High-elevation species, which are more resistant to cooler temperatures, appear to have experienced population declines as recently as the last glaciation (0.016-0.032Ma). In contrast, salamanders dwelling in the warmer and wetter habitats at low-elevation environs appear to have been affected less by the relatively recent, milder glaciation, and more so by harsher, extensive glaciations (0.5-0.175 Ma). Thus, elevation, topography and cold tolerance appear to drive evolutionary patterns of diversification and demography even among closely related taxa. The comparison of multiple species in genealogical analyses can lead to an understanding of the evolutionary drivers.

  16. Linking the pacific decadal oscillation to seasonal stream discharge patterns in Southeast Alaska

    Neal, E.G.; Todd, Walter M.; Coffeen, C.


    This study identified and examined differences in Southeast Alaskan streamflow patterns between the two most recent modes of the Pacific decadal oscillation (PDO). Identifying relationships between the PDO and specific regional phenomena is important for understanding climate variability, interpreting historical hydrological variability, and improving water-resources forecasting. Stream discharge data from six watersheds in Southeast Alaska were divided into cold-PDO (1947-1976) and warm-PDO (1977-1998) subsets. For all watersheds, the average annual streamflows during cold-PDO years were not significantly different from warm-PDO years. Monthly and seasonal discharges, however, did differ significantly between the two subsets, with the warm-PDO winter flows being typically higher than the cold-PDO winter flows and the warm-PDO summer flows being typically lower than the cold-PDO flows. These results were consistent with and driven by observed temperature and snowfall patterns for the region. During warm-PDO winters, precipitation fell as rain and ran-off immediately, causing higher than normal winter streamflow. During cold-PDO winters, precipitation was stored as snow and ran off during the summer snowmelt, creating greater summer streamflows. The Mendenhall River was unique in that it experienced higher flows for all seasons during the warm-PDO relative to the cold-PDO. The large amount of Mendenhall River discharge caused by glacial melt during warm-PDO summers offset any flow reduction caused by lack of snow accumulation during warm-PDO winters. The effect of the PDO on Southeast Alaskan watersheds differs from other regions of the Pacific Coast of North America in that monthly/seasonal discharge patterns changed dramatically with the switch in PDO modes but annual discharge did not. ?? 2002 Elsevier Science B.V. All rights reserved.

  17. Are extreme rainfall intensities more frequent? Analysis of trends in rainfall patterns relevant to urban drainage systems.

    De Toffol, S; Laghari, A N; Rauch, W


    The fact that climate change is affecting the intensity and frequency of rainfall is well accepted in the scientific community. This is backed by a multitude of reports on the basis of daily rainfall series analysis; however, little research is available for short duration intensities. Due to its significant influence on the behaviour of urban drainage, it is critical to investigate the changes in short duration rainfall intensities. In this study different intensities relevant for the urban drainage and the total rainfall per rain event are analysed. The trend is investigated using the Mann-Kendall test. The rainfall series analysed are from the alpine region Tyrol. The results present differences depending on the duration of the intensity and the series considered, however an increase in the number of extreme events is detectable for short durations for the most series.

  18. Quaternary Reorganization of North American Mid-continent Drainage Systems

    Carson, E. C.; Rawling, J. E., III; Attig, J. W.; Bates, B. R.


    Identification of ancestral drainage systems in the North American mid-continent has been a topic of research and debate among geologists since the middle of the 19th Century. Over time our understanding of the significance of Quaternary glaciations in reshaping drainage patterns has grown. The ancestral Teays River, which drained large areas of the central Appalachians and flowed westward across Indiana and western Illinois, was dammed multiple times by Quaternary glaciers before finally being rerouted to the course of the modern central Ohio River. Similarly, the northward-flowing ancestral Pittsburgh River was dammed by pre-Illinoian glaciers; subsequent stream piracy converted this river system into the modern Allegheny, Monongahela and uppermost Ohio Rivers. Deposits and geomorphic features along the westward-flowing lower Wisconsin River indicate that the modern upper Mississippi River and Wisconsin River may have experienced a similar history of ice blockage, stream piracy, and radical rerouting. Coring into the Bridgeport strath terrace along the lower Wisconsin River reveals that the bedrock surface dips to the east, indicating the valley was cut by an eastward-flowing river. We believe the most likely scenario following this interpretation is that an ancestral river flowing along the modern upper Mississippi River valley made a sharp bend at Prairie du Chien, WI, and flowed eastward along the valley occupied by the modern lower Wisconsin River. This river, referred to here as the Wyalusing River, likely flowed northeastward into the Great Lakes (St. Lawrence) drainage until that path was blocked by ice advancing from the northwest. Subsequent stream piracy immediately south of the modern confluence of the Mississippi and Wisconsin Rivers rerouted these streams, converting them to the headwaters of the greater Mississippi drainage. The combined rerouting of these river systems into entirely different drainage basins necessitates significant fundamental

  19. Spatial and seasonal patterns in stream water contamination across mountainous watersheds: Linkage with landscape characteristics

    Ai, L.; Shi, Z. H.; Yin, W.; Huang, X.


    Landscape characteristics are widely accepted as strongly influencing stream water quality in heterogeneous watersheds. Understanding the relationships between landscape and specific water contaminant can greatly improve the predictability of potential contamination and the assessment of contaminant export. In this work, we examined the combined effects of watershed complexity, in terms of land use and physiography, on specific water contaminant across watersheds close to the Danjiangkou Reservoir. The land use composition, land use pattern, morphometric variables and soil properties were calculated at the watershed scale and considered potential factors of influence. Due to high co-dependence of these watershed characteristics, partial least squares regression was used to elucidate the linkages between some specific water contaminants and the 16 selected watershed characteristic variables. Water contaminant maps revealed spatial and seasonal heterogeneity. The dissolved oxygen values in the dry season were higher than those in the wet season, whereas the other contaminant concentrations displayed the opposite trend. The studied watersheds which are influenced strongly by urbanization, showed higher levels of ammonia nitrogen, total phosphorus, potassium permanganate index and petroleum, and lower levels of dissolved oxygen. The urban land use, largest patch index and the hypsometric integral were the dominant factors affecting specific water contaminant.

  20. Visualization in Big Data: A tool for pattern recognition in data stream

    SOARES, V. H. A.


    Full Text Available The development of new technologies is responsible for the generation and storage of continuous and massive amounts of data. Such type of data is known as data stream. The analysis of data streams may be advantageous in many elds, like bioinformatics, medicine, companies and others, as it may result in important information about the data. In this work, we propose a new software tool for Data Visualization that permits the analysis of the evolution of clusters in real time during the data streaming. The proposed visualization tool is add-on for SAMOA, a new variant of MOA (Massive Online Analysis for massive data streams mining and processing distribution.

  1. Cornell University remote sensing program. [application to waste disposal site selection, study of drainage patterns, and water quality management.

    Liang, T.; Mcnair, A. J.; Philipson, W. R.


    Aircraft and satellite remote sensing technology were applied in the following areas: (1) evaluation of proposed fly ash disposal sites; (2) development of priorities for drainage improvements; (3) state park analysis for rehabilitation and development; (4) watershed study for water quality planning; and (5) assistance project-landfill site selection. Results are briefly summarized. Other projects conducted include: (1) assessment of vineyard-related problems; (2) LANDSAT analysis for pheasant range management; (3) photo-historic evaluation of Revolutionary War sites; and (4) thermal analysis of building insulation. The objectives, expected benefits and actions, and status of these projects are described.

  2. The influence of stream channels on distributions of Larrea tridentata and Ambrosia dumosa in the Mojave Desert, CA, USA: Patterns, mechanisms and effects of stream redistribution

    Schwinning, S.; Sandquist, D.R.; Miller, D.M.; Bedford, D.R.; Phillips, S.L.; Belnap, J.


    Drainage channels are among the most conspicuous surficial features of deserts, but little quantitative analysis of their influence on plant distributions is available. We analysed the effects of desert stream channels ('washes') on Larrea tridentata and Ambrosia dumosa density and cover on an alluvial piedmont in the Mojave Desert, based on a spatial analysis of transect data encompassing a total length of 2775 m surveyed in 5 cm increments. Significant deviations from average transect properties were identified by bootstrapping. Predictably, shrub cover and density were much reduced inside washes, and elevated above average levels adjacent to washes. Average Larrea and Ambrosia cover and density peaked 1??2-1??6 m and 0??5-1??0 m from wash edges, respectively. We compared wash effects in runon-depleted (-R) sections, where washes had been cut off from runon and were presumably inactive, with those in runon-supplemented (+R) sections downslope from railroad culverts to help identify mechanisms responsible for the facilitative effect of washes on adjacent shrubs. Shrub cover and density near washes peaked in both + R and - R sections, suggesting that improved water infiltration and storage alone can cause a facilitative effect on adjacent shrubs. However, washes of < 2 m width in + R sections had larger than average effects on peak cover, suggesting that plants also benefit from occasional resource supplementation. The data suggest that channel networks significantly contribute to structuring plant communities in the Mojave Desert and their disruption has notable effects on geomorphic and ecological processes far beyond the original disturbance sites. ?? 2010 John Wiley & Sons, Ltd.

  3. Water-Quality Characteristics for Sites in the Tongue, Powder, Cheyenne, and Belle Fourche River Drainage Basins, Wyoming and Montana, Water Years 2001-05, with Temporal Patterns of Selected Long-Term Water-Quality Data

    Clark, Melanie L.; Mason, Jon P.


    Water-quality sampling was conducted regularly at stream sites within or near the Powder River structural basin in northeastern Wyoming and southeastern Montana during water years 2001-05 (October 1, 2000, to September 30, 2005) to characterize water quality in an area of coalbed natural gas development. The U.S. Geological Survey, in cooperation with the Wyoming Department of Environmental Quality, characterized the water quality at 22 sampling sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Data for general hydrology, field measurements, major-ion chemistry, and selected trace elements were summarized, and specific conductance and sodium-adsorption ratios were evaluated for relations with streamflow and seasonal variability. Trend analysis for water years 1991-2005 was conducted for selected sites and constituents to assess change through time. Average annual runoff was highly variable among the stream sites. Generally, streams that have headwaters in the Bighorn Mountains had more runoff as a result of higher average annual precipitation than streams that have headwaters in the plains. The Powder River at Moorhead, Mont., had the largest average annual runoff (319,000 acre-feet) of all the sites; however, streams in the Tongue River drainage basin had the highest runoff per unit area of the four major drainage basins. Annual runoff in all major drainage basins was less than average during 2001-05 because of drought conditions. Consequently, water-quality samples collected during the study period may not represent long-term water-quality con-ditions for all sites. Water-quality characteristics were highly variable generally because of streamflow variability, geologic controls, and potential land-use effects. The range of median specific-conductance values among sites was smallest in the Tongue River drainage basin. Median values in that basin ranged from 643 microsiemens per centimeter at 25 degrees Celsius (?S/cm at 25?C) on the

  4. Evidence for self-organization in determining spatial patterns of stream nutrients, despite primacy of the geomorphic template.

    Dong, Xiaoli; Ruhí, Albert; Grimm, Nancy B


    Nutrients in freshwater ecosystems are highly variable in space and time. Nevertheless, the variety of processes contributing to nutrient patchiness, and the wide range of spatial and temporal scales at which these processes operate, obfuscate how this spatial heterogeneity is generated. Here, we describe the spatial structure of stream nutrient concentration, quantify the relative importance of the physical template and biological processes, and detect and evaluate the role of self-organization in driving such patterns. We examined nutrient spatial patterns in Sycamore Creek, an intermittent desert stream in Arizona that experienced an ecosystem regime shift [from a gravel/algae-dominated to a vascular plant-dominated (hereafter, "wetland") system] in 2000 when cattle grazing ceased. We conducted high-resolution nutrient surveys in surface water along a 10-km stream reach over four visits spanning 18 y (1995-2013) that represent different successional stages and prewetland stage vs. postwetland state. As expected, groundwater upwelling had a major influence on nutrient spatial patterns. However, self-organization realized by the mechanism of spatial feedbacks also was significant and intensified over ecosystem succession, as a resource (nitrogen) became increasingly limiting. By late succession, the effects of internal spatial feedbacks and groundwater upwelling were approximately equal in magnitude. Wetland establishment influenced nutrient spatial patterns only indirectly, by modifying the extent of surface water/groundwater exchange. This study illustrates that multiple mechanisms interact in a dynamic way to create spatial heterogeneity in riverine ecosystems, and provides a means to detect spatial self-organization against physical template heterogeneity as a dominant driver of spatial patterns.

  5. An approach to quantify sources, seasonal change, and biogeochemical processes affecting metal loading in streams: Facilitating decisions for remediation of mine drainage

    Kimball, B.A.; Runkel, R.L.; Walton-Day, K.


    Historical mining has left complex problems in catchments throughout the world. Land managers are faced with making cost-effective plans to remediate mine influences. Remediation plans are facilitated by spatial mass-loading profiles that indicate the locations of metal mass-loading, seasonal changes, and the extent of biogeochemical processes. Field-scale experiments during both low- and high-flow conditions and time-series data over diel cycles illustrate how this can be accomplished. A low-flow experiment provided spatially detailed loading profiles to indicate where loading occurred. For example, SO42 - was principally derived from sources upstream from the study reach, but three principal locations also were important for SO42 - loading within the reach. During high-flow conditions, Lagrangian sampling provided data to interpret seasonal changes and indicated locations where snowmelt runoff flushed metals to the stream. Comparison of metal concentrations between the low- and high-flow experiments indicated substantial increases in metal loading at high flow, but little change in metal concentrations, showing that toxicity at the most downstream sampling site was not substantially greater during snowmelt runoff. During high-flow conditions, a detailed temporal sampling at fixed sites indicated that Zn concentration more than doubled during the diel cycle. Monitoring programs must account for diel variation to provide meaningful results. Mass-loading studies during different flow conditions and detailed time-series over diel cycles provide useful scientific support for stream management decisions.

  6. Hydrogeochemical and mineralogical characteristics related to heavy metal attenuation in a stream polluted by acid mine drainage:A case study in Dabaoshan Mine, China

    Huarong Zhao; Beicheng Xia; Jianqiao Qin; Jiaying Zhang


    Dabaoshan Mine,the largest mine in south China,has been developed since the 1970s.Acid mine drainage (AMD) discharged from the mine has caused severe environmental pollution and human health problems.In this article,chemical characteristics,mineralogy of ocher precipitations and heavy metal attenuation in the AMD are discussed based on physicochemical analysis,mineral analysis,sequential extraction experiments and hydrogeochemistry.The AMD chemical characteristics were determined from the initial water composition,water-rock interactions and dissolved sulfide minerals in the mine tailings.The waters,affected and unaffected by AMD,were Ca-SO4 and Ca-HCO3 types,respectively.The affected water had a low pH,high SO42- and high heavy metal content and oxidation as determined by the Fe2+/Fe3+ couple.Heavy metal and SO42- contents of Hengshi River water decreased,while pH increased,downstream.Schwertmannite was the major mineral at the waste dump,while goethite and quartz were dominant at the tailings dam and streambed.Schwertmannite was transformed into goethite at the tailings dam and streambed.The sulfate ions of the secondary minerals changed from bidentate- to monodentate-complexes downstream.Fe-Mn oxide phases of Zn,Cd and Pb in sediments increased downstream.However,organic matter complexes of Cu in sediments increased further away from the tailings.Fe3+ mineral precipitates and transformations controlled the AMD water chemistry.

  7. Formation of inverse Chladni patterns at microscale by acoustic streaming on a silicon membrane immersed in a liquid

    Poulain, Cedric; Vuillermet, Gael; Casset, Fabrice


    High frequency acoustics (in the MHz range) is known to be very efficient to handle micro particles or living cells in microfluidics by taking advantage of the acoustic radiation force. Here, we will show that low frequency (~ 50kHz) together with use ultra thin silicon plate can give rise to a micro streaming that enables to move particles at will. Indeed, by means of silicon membranes excited in the low ultrasound range, we show that it is possible to form inverse two-dimensional Chladni patterns of micro-beads in liquid. Unlike the well-known effect in a gaseous environment at macroscale, where gravity effects are generally dominant, leading particles towards the nodal regions of displacement, we will show that the micro scale streaming in the vicinity of the plate tends to gather particles in antinodal regions. Moreover, a symmetry breaking effect together with the streaming can trigger a whole rotation of the beads in the fluidic cavity. We demonstrate that it is possible to make the patterns rotate at a well defined angular velocity where beads actually jump from one acoustic trap to another.

  8. Exploring Agricultural Drainage's Influence on Wetland and ...

    Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie

  9. Generation-scale movement patterns of cutthroat trout (Oncorhynchus clarkii pleuriticus) in a stream network

    Michael K. Young


    Movements by stream fishes have long been the subject of study and controversy. Although much discussion has focused on what proportion of fish adopt mobility within particular life stages, a larger issue involves the lifetime movements of individuals. I evaluated movements of different sizes and ages of Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus...

  10. Use of continuous monitoring to assess stream nitrate flux and transformation patterns.

    Jones, Christopher; Kim, Sea-Won; Schilling, Keith


    Delivery of nitrogen from farmed fields to the stream network is an ongoing water quality issue in central North America and other parts of the world. Although fertilization and other farming practices have been refined to produce environmental improvements, stemming loss of nitrogen, especially in the soluble nitrate form, is a problem that has seemingly defied solution. The Iowa Nutrient Reduction Strategy is a policy initiative designed to implement conservation and other farm management practices to produce reductions in nitrate loading. The strategy does not focus on how the streams themselves may or may not be processing nitrogen and reducing downstream loading. We used continuous high-frequency nitrate and discharge monitoring over 3 years at two sites separated by 18 km in a low-order, agricultural stream in eastern Iowa to estimate how nitrogen is processed, and whether or not these processes are reducing downstream loading. We conclude that the upstream to downstream nitrate concentration decline between the two sites was not driven by denitrification. These data also show that nitrate concentrations are closely coupled to discharge during periods of adequate moisture, but decoupling of concentration from discharge occurs during dry periods. This decoupling is a possible indicator of in-stream nitrate processing. Finally, nitrate concentrations are likely diluted by water sourced from non-row crop land covers in the lower reaches of the watershed.

  11. Tracking Changes in Dissolved Organic Matter Patterns in Perennial Headwater Streams Throughout a Hydrologic Year Using In-situ Sensors and Optical Properties

    Armstrong, A.; Epting, S.; Hosen, J. D.; Palmer, M.


    Dissolved organic matter (DOM) plays a central role in freshwater streams but key questions remain unanswered about temporal patterns in its quantity and composition. DOM in perennial streams in the temperate zone is a complex mixture reflecting a variety of sources such as leached plant material, organic matter from surrounding soils, and microbial processes in the streams themselves. Headwater perennial streams in the Tuckahoe Creek watershed of the Atlantic coastal plain (Maryland, USA) drain a mosaic of land cover types including row crops, forests, and both forested and marshy small depressional wetlands. Wetland-stream surface hydrologic connections generally occur between mid-fall and late spring, coinciding with peak wetland hydrologic expression (i.e. highest groundwater levels and surface inundation extent). When inundated, these wetlands contain high DOM concentrations, and surface connections may serve as conduits for downstream export. We hypothesized that changes in wetland-stream surface hydrologic connectivity would affect patterns of DOM concentration and composition in these streams. We deployed 6 sondes equipped with fluorescent DOM sensors in 4 perennial streams, 1 forested wetland, and the larger downstream channel draining all study sites for the 2015 water year. The 4 headwater streams drain areas containing forested wetlands and have documented temporary channel connections. Combined with baseflow and stormflow sampling, the sondes provided 15 minute estimates of dissolved organic carbon (DOC) concentrations. This resolution provided insights into patterns of DOC concentration across temporal scales from daily rhythms to seasonal changes, during both baseflow and storm conditions. Discrete measurements of absorbance and fluorescence provided information about DOM composition throughout the study. Together these measurements give a detailed record of DOM dynamics in multiple perennial headwater streams for an entire year. This information

  12. Pattern of lymph node metastases of squamous cell esophageal cancer based on the anatomical lymphatic drainage system: efficacy of lymph node dissection according to tumor location


    Knowing the anatomical lymphatic drainage of the esophagus is crucial to understanding the dissemination pattern of esophageal tumor. During the embryonal growth, the middle and lower part of the esophagus stretches as the lymphatic networks develop in the submucosal layer. The abundant submucosal lymphatics drain in a longitudinal fashion directly to their proximal and distal ends. The lymphatic route from the proximal esophagus through recurrent nerve nodes to supraclavicular nodes are a component of the mesentery of the proximal esophagus. The lower esophagus mostly drains its lymph into paracardial nodes related to celiac nodes through the mesentery of the distal esophagus. Lymphatic routes to mid and lower paraesophageal nodes usually originate from the intermuscular area of the muscularis propria. The lymphatic communication between the submucosa and intermuscular area is limited. The anatomical concept was confirmed clinically by a large series of single institution and the nationwide registry in Japan. The clinical data for the incidence of involved nodes verified the anatomical observations that long longitudinal extension of lymphatic drainage in the submucosa connected to the upper mediastinum lymphatics and paracardial lymphatics. The extent of dissection should be not tailored according to the anatomical distance from the tumor but according to the incidences of metastasis of each area, those were differed by tumor location. The areas for node dissection should be modified according to the tumor location. Although in patients with tumor limited to within the submucosal layer, even with tumors located in the mid- and lower esophagus, lymphatic metastasis was frequent in the upper mediastinum and perigastric area via the abundant submucosal lymphatics in a longitudinal fashion. When tumor invades or penetrates the muscle layer, the incidence of paraesophageal lymph node metastasis in the middle and lower mediastinum increases. PMID:28815068

  13. Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

    Emma Göthe


    Full Text Available The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

  14. Implication of drainage basin parameters of a tropical river basin of South India

    Babu, K. J.; Sreekumar, S.; Aslam, Arish


    Drainage morphometry provides quantitative description of the drainage system which is an important aspect of the characterisation of watersheds. Chalakudi River is one of the important rivers of the South India which has attracted attention of many environmental scientists recently because of the proposed Athirapally Hydel Project across the river. SRTM (Shuttle Radar Topographic Mission) data were used for preparing DEM (Digital Elevation Model), Aspect Map and Slope Map. Geographical Information System (GIS) was used for the evaluation of linear, areal and relief aspects of morphometric parameters. The study reveals that the terrain exhibits dentritic and trellis pattern of drainage. The Chalakudi River Basin has a total area of 1,448.73 km2 and is designated as seventh-order basin. The drainage density of the basin is estimated as 2.54 and the lower-order streams mostly dominate the basin. The high basin relief indicates high runoff and sediment transport. The elongation ratio of the Chalakudi Basin is estimated as 0.48 and indicates that the shape of the basin is elongated. The development of stream segments in the basin area is more or less effected by rainfall. Relief ratio indicates that the discharge capability of watershed is very high and the groundwater potential is meagre. The low value of drainage density in spite of mountainous relief indicates that the area is covered by dense vegetation and resistant rocks permeated by fractures and joints. These studies are helpful in watershed development planning and wise utilization of natural resources.

  15. Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

    Shilei Liu


    Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.

  16. Patterns in stream fish assemblage structure and function associated with a PCB gradient.

    Simon, Thomas P; Morris, Charles C; Sparks, Daniel W


    Stream fish assemblage structure and function were examined for significant response along a polychlorinated biphenyl (PCB) gradient from two PCB-contaminated streams (Clear Creek and Richland Creek watershed) at three locations and a control stream (Little Indian Creek), Indiana, USA. Fish were sampled in the summer months of 1995 and from 1999 to 2002. 51 fish assemblage attributes-including structure (i.e., fish composition) and function (i.e., trophic, reproductive, condition guilds), biomass, and index of biotic integrity (IBI) metric scores-were evaluated for significance according to an increasing PCB gradient. Eight biomass attributes of fish assemblages decreased with increasing PCB concentration: number of species biomass, number of sunfish biomass, percent sunfish biomass, number of sucker biomass, percent sucker biomass, biomass of sensitive species, percent sensitive species biomass, and percent carnivore biomass. Three biomass attributes increased with PCB concentration: percent minnow biomass, percent pioneer species biomass, and percent tolerant species biomass. Seven species composition and relative abundance characters decreased with increasing PCB concentration: number of species; number of darter, madtom, and sculpin; number of darter; number of sunfish; number of sucker; number of sensitive species; and percent individuals as carnivores. Percent individuals as pioneer species increased with increasing PCB concentration. Two IBI metrics, percent individuals as headwater species and number of minnow species, increased as PCB concentrations increased, whereas number of sucker species and percent individuals as pioneer species decreased with increasing PCB concentration class. We observed a direct response between decreased relative abundance and biomass of carnivores and increased relative abundance minnows as the PCB gradient increased. Total IBI score did not detect subtle changes to the fish community that were observed along a PCB gradient

  17. Patterns of hybridization among cutthroat trout and rainbow trout in northern Rocky Mountain streams.

    McKelvey, Kevin S; Young, Michael K; Wilcox, Taylor M; Bingham, Daniel M; Pilgrim, Kristine L; Schwartz, Michael K


    Introgressive hybridization between native and introduced species is a growing conservation concern. For native cutthroat trout and introduced rainbow trout in western North America, this process is thought to lead to the formation of hybrid swarms and the loss of monophyletic evolutionary lineages. Previous studies of this phenomenon, however, indicated that hybrid swarms were rare except when native and introduced forms of cutthroat trout co-occurred. We used a panel of 86 diagnostic, single nucleotide polymorphisms to evaluate the genetic composition of 3865 fish captured in 188 locations on 129 streams distributed across western Montana and northern Idaho. Although introgression was common and only 37% of the sites were occupied solely by parental westslope cutthroat trout, levels of hybridization were generally low. Of the 188 sites sampled, 73% contained ≤5% rainbow trout alleles and 58% had ≤1% rainbow trout alleles. Overall, 72% of specimens were nonadmixed westslope cutthroat trout, and an additional 3.5% were nonadmixed rainbow trout. Samples from seven sites met our criteria for hybrid swarms, that is, an absence of nonadmixed individuals and a random distribution of alleles within the sample; most (6/7) were associated with introgression by Yellowstone cutthroat trout. In streams with multiple sites, upstream locations exhibited less introgression than downstream locations. We conclude that although the widespread introduction of nonnative trout within the historical range of westslope cutthroat trout has increased the incidence of introgression, sites containing nonadmixed populations of this taxon are common and broadly distributed.

  18. Social-ecological drivers of multiple ecosystem services: what variables explain patterns of ecosystem services across the Norrström drainage basin?

    Megan Meacham


    Full Text Available In human dominated landscapes many diverse, and often antagonistic, human activities are intentionally and inadvertently determining the supply of various ecosystem services. Understanding how different social and ecological factors shape the availability of ecosystem services is essential for fair and effective policy and management. In this paper, we evaluate how well alternative social-ecological models of human impact on ecosystems explain patterns of 16 ecosystem services (ES across the 62 municipalities of the Norrström drainage basin in Sweden. We test four models of human impact on ecosystems, land use, ecological modernization, ecological footprint, and location theory, and test their ability to predict both individual ES and bundles of ES. We find that different models do best to predict different types of individual ES. Land use is the best model for predicting provisioning services, standing water quality, biodiversity appreciation, and cross-country skiing, while other models work better for the remaining services. However, this range of models is not able to predict some of the cultural ES. ES bundles are predicted worse than individual ES by these models, but provide a clear picture of variation in multiple ecosystem services based on limited information. Based on our results, we offer suggestions on how social-ecological modeling and assessments of ecosystems can be further developed.

  19. A Stream Morphology Classification for Eco-hydraulic Purposes Based on Geospatial Data: a Solute Transport Application Case

    Jiménez Jaramillo, M. A.; Camacho Botero, L. A.; Vélez Upegui, J. I.


    Variation in stream morphology along a basin drainage network leads to different hydraulic patterns and sediment transport processes. Moreover, solute transport processes along streams, and stream habitats for fisheries and microorganisms, rely on stream corridor structure, including elements such as bed forms, channel patterns, riparian vegetation, and the floodplain. In this work solute transport processes simulation and stream habitat identification are carried out at the basin scale. A reach-scale morphological classification system based on channel slope and specific stream power was implemented by using digital elevation models and hydraulic geometry relationships. Although the morphological framework allows identification of cascade, step-pool, plane bed and pool-riffle morphologies along the drainage network, it still does not account for floodplain configuration and bed-forms identification of those channel types. Hence, as a first application case in order to obtain parsimonious three-dimensional characterizations of drainage channels, the morphological framework has been updated by including topographical floodplain delimitation through a Multi-resolution Valley Bottom Flatness Index assessing, and a stochastic bed form representation of the step-pool morphology. Model outcomes were tested in relation to in-stream water storage for different flow conditions and representative travel times according to the Aggregated Dead Zone -ADZ- model conceptualization of solute transport processes.

  20. Greenland Ice Sheet supraglacial stream morphology and dynamics

    Chu, V.; Smith, L. C.; Yang, K.; Legleiter, C. J.; Rennermalm, A. K.; Forster, R. R.; Gleason, C. J.; Pitcher, L. H.; Moustafa, S.


    Recently observed increases in temperature and melt extent over the Greenland Ice Sheet (GrIS) have prompted studies gauging the response of the ice sheet and outlet glaciers to increasing meltwater input. Satellite images show supraglacial streams abundantly covering the western ablation zone throughout the melt season that transport large volumes of meltwater into moulins and to the ice edge, yet these streams remain poorly studied. Here, we present a high-resolution study of five different supraglacial stream networks in the western GrIS ablation zone, manually digitized from panchromatic and multispectral WorldView-1/2 imagery. These high-resolution stream networks, with drainage areas ranging between 0.5 - 31 km2 in size and 500 - 1800 m in elevation, are compared with large rivers extracted from multispectral WorldView-2 imagery using an automated remote sensing method, and can help define scaling properties of larger rivers as well as constrain remotely sensed retrievals of discharge. Four of these stream networks contain field measurements of stream hydraulics from a field campaign during 20 July - 20 August 2012. This extensive field campaign provided 77 cross-sectional measurements of water flow velocity, stream depth, width, and water surface slope from traditional field surveys, and also provided longitudinal measurements of water surface velocity and elevation from river drifters. Additionally, two highly sampled sites at 500 m and 875 m elevation provide measurements of ablation rate, stream incision rate, and stream and air temperatures. These drainage networks are categorized by discharge, glacier slope, width-to-depth ratio, channel roughness, Froude number, meander wavelength, sinuosity, and channel pattern. Such measurements form a critical first assessment of GrIS supraglacial stream morphology and dynamics.

  1. The Geochemistry of Acid Mine Drainage

    Blowes, D. W.; Ptacek, C. J.; Jambor, J. L.; Weisener, C. G.


    Mine wastes are the largest volume of materials handled in the world (ICOLD, 1996). The generation of acidic drainage and the release of water containing high concentrations of dissolved metals from these wastes is an environmental problem of international scale. Acidic drainage is caused by the oxidation of sulfide minerals exposed to atmospheric oxygen. Although acid drainage is commonly associated with the extraction and processing of sulfide-bearing metalliferous ore deposits and sulfide-rich coal, acidic drainage can occur wherever sulfide minerals are excavated and exposed to atmospheric oxygen. Engineering projects, including road construction, airport development, and foundation excavation are examples of civil projects that have resulted in the generation of acidic drainage. On United States Forest Service Lands there are (2-5)×104 mines releasing acidic drainage (USDA, 1993). Kleinmann et al. (1991) estimated that more than 6,400 km of rivers and streams in the eastern United States have been adversely affected by mine-drainage water. About (0.8-1.6)×104 km of streams have been affected by metal mining in the western United States. The annual worldwide production of mine wastes exceeded 4.5 Gt in 1982 (ICOLD, 1996). Estimated costs for remediating mine wastes internationally total in the tens of billions of dollars ( Feasby et al.,1991).

  2. The role of species functional traits for distribuitional patterns in lowland stream vegetation

    Cavalli, Giulia; Baattrup-Pedersen, Annette; Riis, Tenna

    a gradient in size and water alkalinity. We applied a co-inertia analysis including functional traits (e.g. life form, vegetative propagation, pollen vector), bioindicator values and Grime CSR scores to investigate their significance for species distributional pattern. We found a clear correlation between...

  3. Movement patterns of Brook Trout in a restored coastal stream system in southern Massachusetts

    Snook, Erin L.; Letcher, Benjamin H.; Dubreuil, Todd L.; Zydlewski, Joseph; O'Donnell, Matthew J.; Whiteley, Andrew R.; Hurley, Stephen T.; Danylchuk, Andy J.


    Coastal Brook Trout (Salvelinus fontinalis) populations are found from northern Canada to New England. The extent of anadromy generally decreases with latitude, but the ecology and movements of more southern populations are poorly understood. We conducted a 33-month acoustic telemetry study of Brook Trout in Red Brook, MA, and adjacent Buttermilk Bay (marine system) using 16 fixed acoustic receivers and surgically implanting acoustic transmitters in 84 individuals. Tagged Brook Trout used the stream, estuary (50% of individuals) and bay (10% of individuals). Movements into full sea water were brief when occurring. GAMM models revealed that transitions between habitat areas occurred most often in spring and fall. Environmental data suggest that use of the saline environment is limited by summer temperatures in the bay. Movements may also be related to moon phase. Compared to more northern coastal populations of Brook Trout, the Red Brook population appears to be less anadromous overall, yet the estuarine segment of the system may have considerable ecological importance as a food resource.

  4. Coarse-scale movement patterns of a small-bodied fish inhabiting a desert stream

    Dzul, M.C.; Quist, M.C.; Dinsmore, S.J.; Gaines, D.B.; Bower, M.R.


    Located on the floor of Death Valley (CA, USA), Salt Creek harbors a single fish species, the Salt Creek pupfish, Cyprinodon salinus salinus, which has adapted to this extremely harsh environment. Salt Creek is fed by an underground spring and is comprised of numerous pools, runs, and marshes that exhibit substantial variability in temperature, salinity, and dissolved oxygen concentrations. In addition, the wetted area of Salt Creek is reduced throughout the summer months due to high rates of evaporation, with some reaches drying completely. Therefore, it seems logical that short- and long-term movement patterns may play an important role in Salt Creek pupfish population dynamics. The objective of this study was to describe coarse-scale movements of Salt Creek pupfish in Salt Creek during their breeding season from March to May. Sex ratios and length–frequency distributions varied spatially within Salt Creek, suggesting population segregation during the breeding season. Long-distance movements were generally rare, although two fish moved more than 1.2 km. Movement in upstream reaches was rare or absent, in contrast to the greater movement observed in downstream reaches (29% of recaptures). Temporal trends and demographic patterns in movement were not observed. Because the two most downstream habitats dry up in the summer, our results indicate that coarse-scale movements that re-populate downstream reaches likely occur during other times of year. Consequently, the importance of small- and large-scale movements is influenced by season. Further assessment of Salt Creek movement patterns conducted during other times of year may better illuminate long-distance movement patterns and source-sink dynamics.

  5. Drainage-Area Data for Wisconsin Streams


    Mich., 42 N 35 W SW1/4SE1/4 21 Iron 7 2.07 at mouth (Mich .) )4059903 Huff Creek near Tipler , at mouth 41 N 15 E NW1/4SE1/4 31 Florence 7 5 .52 )4059904...Chuks Creek near Tipler , at mouth 41 N 15 E NE1/4SE1/4 31 Florence 7 1 .98 )4059905 Duck Creek near Tipler , at mouth 41 N 15 E NW1/4SW1/4 32 Florence...7 3 .32 )4059906 Brule River near Tipler , State Highway 189 42 N 35 E NE1/4SW1/4 35 Iron 7 164 (Mich .) and State Highway 139 (Wis .) (Mich

  6. Complex Drainage Response To Migrating Tectonic Uplift: Example From The Northern California Coast Ranges

    Lock, J.; Furlong, K. P.

    Migration of the Mendocino triple junction in northern California produces rapid and dramatic changes in the processes and patterns of crustal deformation. In response to this tectonism, the river systems of the northern California Coast Ranges have devel- oped a complex drainage history and pattern. The tectonic response to this migrating triple junction is described by the Mendocino Crustal Conveyor model (MCC), which predicts a spatially and temporally varying pattern of crustal deformation and up- lift. We use a combination of geomorphic and geophysical observations, coupled with landscape evolution modeling to develop the links between the geomorphic observa- tions in the Coast Ranges and the uplift/subsidence pattern predicted by the MCC. In contrast to many previous landscape evolution studies that find that streams typically cut through or are diverted around growing structures, in the northern California Coast Ranges drainage reversal and stream capture appear to be the response to tectonism. Our landscape evolution modeling shows that the uplift predicted by the MCC pro- duces: (1) a topographic gradient that switches from trending northwest to southeast, causing streams that at first flow to the northwest to reverse and drain to the south- east, (2) drainage divides that migrate in concert with the triple junction, and (3) river evolution that will result in fish hooked drainage patterns, all characteristics similar to those observed in the Northern California Coast Ranges. The uplift/subsidence pat- tern in the northern Coast Ranges is further complicated by the interaction of a second tectonic driver - the Pioneer fragment. The Pioneer fragment migrates with the Pacific (south of the triple junction) and creates a mini-slab window, adjacent to the coast, to produce a superimposed secondary uplift/subsidence pattern. The effects of this Pioneer related uplift are recorded by the Eel River. Key to the complex evolution of river systems in northern

  7. Coastal uplift west of Algiers (Algeria): pre- and post-Messinian sequences of marine terraces and rasas and their associated drainage pattern

    Authemayou, Christine; Pedoja, Kevin; Heddar, Aicha; Molliex, Stéphane; Boudiaf, Azzedine; Ghaleb, Bassam; Van Vliet Lanoe, Brigitte; Delcaillau, Bernard; Djellit, Hamou; Yelles, Karim; Nexer, Maelle


    The North Africa passive margin is affected by the ongoing convergence between the African and Eurasian plates. This convergence is responsible for coastal uplift, folding, and reverse faulting on new and reactivated faults on the margin. The active deformation is diffuse and thus rather difficult to locate precisely. We aim to determine how a coastal landscape evolve in this geodynamic setting and gain insights into active tectonics. More particularly, we evidence and quantify coastal uplift pattern of the Chenoua, Sahel, and Algiers reliefs (Algeria), using sequences of marine terraces and rasas and computing several morphometric indices from the drainage pattern. Upper and Middle Pleistocene uplift rates are obtained by fossil shoreline mapping and preliminary U/Th dating of associated coastal deposits. Extrapolation of these rates combined to analyses of sea-level referential data and spatial relationships between marine terraces/rasas and other geological markers lead us to tentatively propose an age for the highest coastal indicators (purported the oldest). Values of morphometric indices showing correlations with uplift rate allow us to analyze uplift variation on area devoid of coastal sequence. Geological and geomorphological data suggest that coastal uplift probably occurred since the Middle Miocene. It resulted in the emergence of the Algiers massif, followed by the Sahel ridge massif. The Sahel ridge has asymmetrically grown by folding from west to east and was affected by temporal variation of uplift. Compared to previous study, the location of the Sahel fold axis has been shifted offshore, near the coast. The Chenoua fault vertical motion does not offset significantly the coastal sequence. Mean apparent uplift rates and corrected uplift rates since 120 ka are globally steady all along the coast with a mean value of 0.055 ± 0.015 mm/year (apparent) and of 0.005 ± 0.045 mm/year (corrected for eustasy). Mean apparent coastal uplift rates between 120 and

  8. A synthesis and comparative evaluation of drainage water management

    Viable large-scale crop production in the United States requires artificial drainage in humid and poorly drained agricultural regions. Excess water removal is generally achieved by installing tile drains that export water to open ditches that eventually flow into streams. Drainage water management...

  9. Late cenozoic evolution of Fortymile Ash: Major change in drainage pattern in the Yucca Mountain, Nevada region during late miocene volcanism

    Lundstrom, S.C. [Geological Survey, Las Vegas, NV (United States); Warren, R.G. [Los Alamos National Lab., NM (United States)


    Analysis of sedimentary provenance and altitude distribution of volcanic strata along Fortymile Wash, the primary desert wash east of Yucca Mountain, NV, indicates a major change in surface drainage basins related to late Miocene volcanic disruption. This event resulted in the establishment of the modern Fortymile Wash basin before 3 Ma, and probably by latest Miocene time. An understanding of this event is useful for evaluation of extensive alluviation east of Yucca Mountain and its relation to paleoclimate, hydrology and tectonics. To the northeast of Yucca Mountain, Fortymile Wash provides southward surface drainage from 60% of the area of the 11 Ma Timber Mountain caldera via Fortymile Canyon, a major breach in the caldera wall. In the southeast caldera moat, the distribution of volcanic units that predate and include the 9.4 Ma Thirsty Canyon Group and the characteristics of intercalated sediments indicate a northward paleoslope and sediment transport from a major drainage divide near Dome Mountain, a shield volcano now deeply incised by Fortymile Canyon. Eruption of the Thirsty Canyon Group from the Black Mountain area, 10 km northwest of the Timber Mountain caldera, is likely to have dammed a counterclockwise drainage system of the east moat. Following drainage disruption, the east moat filled with sediment up to the level of a new southward outlet at the saddle between Dome Mountain and the onlapping rhyolite of Shoshone Mountain. An older canyon south of this saddle received the overflow from the east moat and became the throughgoing Fortymile Canyon, integrating the east moat basin with a lower base level in Jackass Flats. Well-integrated southward drainage existed by the time the trachybasalt flows of Buckboard Mesa (2.8 Ma) were emplaced, because basal elevations of these flows slope southward about 100 m above modern Fortymile Wash.

  10. Distributed Parallel Algorithm of Mining Frequent Pattern on Data Stream%分布式并行化数据流频繁模式挖掘算法

    马可; 李玲娟; 孙杜靖


    为了提高数据流频繁模式挖掘的效率,文中基于经典的数据流频繁模式挖掘算法FP-Stream和分布式并行计算原理,设计了一种分布式并行化数据流频繁模式挖掘算法—DPFP-Stream ( Distributed Parallel Algorithm of Mining Frequent Pattern on Data Stream)。该算法将建立频繁模式树的任务分为local和global两部分,并设置了参数“当前时间”;将到达的流数据平均分配到多个不同的local节点,各local节点使用FP-Growth算法产生该单位时间内本节点的候选频繁项集,并按照单位时间将候选频繁项集及其支持度计数打包发送至global节点;global节点按“当前时间”合并各local节点的中间结果并更新模式树Pattern-Tree。在分布式数据流计算平台Storm上进行的算法实现和性能测试结果表明,DPFP-Stream算法的计算效率能够随着local节点或local bolt线程的增加而提高,适用于高效挖掘数据流中的频繁模式。%In order to improve the efficiency of mining frequent pattern on data stream,a Distributed Parallel Algorithm of Mining Fre-quent Pattern on Data Stream,named DPFP-Stream,is designed in this paper based on the ideas of classical FP-Stream and the distribu-ted parallel computing. It divides the task of building frequent pattern tree into two parts:local and global,and introduces a new parameter“current time”. The arrival data will be equally distributed into different local nodes. Then every local node uses FP-Growth algorithm to produce candidate frequent items,and packages them with relevant support count according to unit time,and sends them to the global node. The global node combines the results produced by local nodes according to the“current time” and updates the global Pattern-Tree. The results of implementing DPFP-Stream algorithm and testing its performance on Storm,a distribution data stream computing platform, show that the computing efficiency of DPFP-Stream can

  11. Drainage network over the migrating front of dynamic uplift in Patagonia

    Jeandet, Louise; Robert, Xavier; Audin, Laurence; Husson, Laurent; Guillaume, Benjamin


    Dynamic topography disturbs the regional morphology at long wavelength and with very low topographic gradients. Nevertheless, fluvial erosion and the drainage pattern should respond to the spatial and temporal topographic variations. In Patagonia, the mid-Miocene, opening and northward migration of an asthenospheric window beneath the South American plate triggered a northward propagating wave of dynamic topography. Based on a morphometric analysis, we explore the long-wavelength response of the drainage system to the recent dynamics of the continental lithosphere. Our analysis of Patagonian rivers (stream profile analysis) and basins (R/Sr analysis) shows a transient state of the drainage network responding to a likely recent signal that prevails at the latitudes of the Chile Triple Junction in Argentina. Moreover, the distribution of the perturbation signal among the drainage network shows a South-to-North gradient, with the low Strahler order tributaries more affected with increasing latitudes. We interpret this observation as the differential timing of response to a Northward propagating signal of dynamic topography. We further use the geometry of the drainage network combined to numerical model predictions to infer the characteristic response time of the surface processes. While the main tributaries respond within ~1-3 Ma, the lower order remain disturbed for longer times. This observation is further supported by the persistently high mean elevation where incision is high, which we take as indicative of the fact that erosion has not yet thoroughly achieved its resurfacing action.

  12. Mercury bioaccumulation in a stream network.

    Tsui, Martin Tsz Ki; Finlay, Jacques C; Nater, Edward A


    Mercury (Hg) contamination is common in stream and river ecosystems, but factors mediating Hg cycling in the flowing waters are much less understood than inthe lakes and wetlands. In this study, we examined the spatial patterns of methylmercury (MeHg) concentrations in the dominant groups of aquatic insect larvae across a network of streams (drainage area ranging from 0.5 to 150 km2) in northern California during summer baseflow conditions. We found that, with the exception of water striders, all invertebrate groups showed significant (p South Fork Eel River, had the highest aqueous MeHg concentration (unfiltered: 0.13-0.17 ng L(-1)) while most of the upstream tributaries had aqueous MeHg concentrations close to or below the established detection limits (0.02 ng L(-1)). A filamentous alga abundant in South Fork Eel River (Cladophora glomerata) had an exceptionally high fraction of total-Hg as MeHg (i.e., %MeHg from 50-100%). Since other potential hotspots of in-stream Hg methylation (e.g., surface sediment and deep pools) had %MeHg lower than or similar to surface water (approximately 14%), we hypothesize that Cladophora and possibly other autotrophs may serve as hotspots of in-stream MeHg production in this bedrock-dominated stream. Recent studies in other regions concluded that wetland abundance in the watershed is the predominant factor in governing Hg concentrations of stream biota. However, our results show that in the absence of wetlands, substantial spatial variation of Hg bioaccumulation can arise in stream networks due to the influence of in-stream processes.

  13. Ecoregions and stream morphology in eastern Oklahoma

    Splinter, D.K.; Dauwalter, D.C.; Marston, R.A.; Fisher, W.L.


    Broad-scale variables (i.e., geology, topography, climate, land use, vegetation, and soils) influence channel morphology. How and to what extent the longitudinal pattern of channel morphology is influenced by broad-scale variables is important to fluvial geomorphologists and stream ecologists. In the last couple of decades, there has been an increase in the amount of interdisciplinary research between fluvial geomorphologists and stream ecologists. In a historical context, fluvial geomorphologists are more apt to use physiographic regions to distinguish broad-scale variables, while stream ecologists are more apt to use the concept of an ecosystem to address the broad-scale variables that influence stream habitat. For this reason, we designed a study using ecoregions, which uses physical and biological variables to understand how landscapes influence channel processes. Ecoregions are delineated by similarities in geology, climate, soils, land use, and potential natural vegetation. In the fluvial system, stream form and function are dictated by processes observed throughout the fluvial hierarchy. Recognizing that stream form and function should differ by ecoregion, a study was designed to evaluate how the characteristics of stream channels differed longitudinally among three ecoregions in eastern Oklahoma, USA: Boston Mountains, Ozark Highlands, and Ouachita Mountains. Channel morphology of 149 stream reaches was surveyed in 1st- through 4th-order streams, and effects of drainage area and ecoregion on channel morphology was evaluated using multiple regressions. Differences existed (?????0.05) among ecoregions for particle size, bankfull width, and width/depth ratio. No differences existed among ecoregions for gradient or sinuosity. Particle size was smallest in the Ozark Highlands and largest in the Ouachita Mountains. Bankfull width was larger in the Ozark Highlands than in the Boston Mountains and Ouachita Mountains in larger streams. Width/depth ratios of the

  14. Accuracy enhancement for forecasting water levels of reservoirs and river streams using a multiple-input-pattern fuzzification approach.

    Valizadeh, Nariman; El-Shafie, Ahmed; Mirzaei, Majid; Galavi, Hadi; Mukhlisin, Muhammad; Jaafar, Othman


    Water level forecasting is an essential topic in water management affecting reservoir operations and decision making. Recently, modern methods utilizing artificial intelligence, fuzzy logic, and combinations of these techniques have been used in hydrological applications because of their considerable ability to map an input-output pattern without requiring prior knowledge of the criteria influencing the forecasting procedure. The artificial neurofuzzy interface system (ANFIS) is one of the most accurate models used in water resource management. Because the membership functions (MFs) possess the characteristics of smoothness and mathematical components, each set of input data is able to yield the best result using a certain type of MF in the ANFIS models. The objective of this study is to define the different ANFIS model by applying different types of MFs for each type of input to forecast the water level in two case studies, the Klang Gates Dam and Rantau Panjang station on the Johor river in Malaysia, to compare the traditional ANFIS model with the new introduced one in two different situations, reservoir and stream, showing the new approach outweigh rather than the traditional one in both case studies. This objective is accomplished by evaluating the model fitness and performance in daily forecasting.

  15. Divergent patterns of abundance and age-class structure of headwater stream tadpoles in burned and unburned watersheds

    Hossack, B.R.; Corn, P.S.; Fagre, D.B.


    Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestern Montana to determine the effects of wildfire on A. montanus. All streams were initially sampled in 2001, 2 years before four of them burned in a large wildfire, and were resampled during the 2 years following the fire. Counts of tadpoles were similar in the two groups of streams before the fire. After the fire, tadpoles were almost twice as abundant in unburned streams than in burned streams. The fire seemed to have the greatest negative effect on abundance of age-1 tadpoles, which was reflected in the greater variation in same-stream age-class structure compared with those in unburned streams. Despite the apparent effect on tadpoles, we do not expect the wildfire to be an extirpation threat to populations in the streams that we sampled. Studies spanning a chronosequence of fires, as well as in other areas, are needed to assess the effects of fires on streams with A. montanus and to determine the severity and persistence of these effects.

  16. [Little Dry Creek Drainage

    US Fish and Wildlife Service, Department of the Interior — Map of the drainage boundary, direction of flow, canals and ditches, and streets for the drainage study plan and profile for Little Dry Creek sub area in the North...

  17. Percutaneous Abscess Drainage

    ... Physician Resources Professions Site Index A-Z Percutaneous Abscess Drainage An abscess is an infected fluid collection ... are the benefits vs. risks? What is Percutaneous Abscess Drainage? An abscess is an infected fluid collection ...

  18. Transient drainage summary report



    This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage.

  19. Spatial and Temporal Patterns of Nutrient Limitation, Plant Biomass and Productivity, and Stream Metabolism Vary in Response to Short- and Long-Term Hydrological Regime Shifts

    Grimm, N. B.; Sabo, J. L.; Dong, X.; Ruhí, A.


    Climate and hydrology are strong drivers of ecosystem structure and function in arid landscapes. Arid regions are characterized by high interannual variation in precipitation, and these climate patterns drive the overall hydrologic disturbance regime (in terms of flooding and drying), which influences geomorphic structure, biotic distributions, and nutrient status of desert stream ecosystems. We analyzed the long-term pattern of discharge in a desert stream in Arizona to identify hydrologic regime shifts, i.e., abrupt transitions between sequences of floods and droughts at periods of months to decades. We used wavelet analysis to identify time intervals over a 50-year time series that were negatively correlated with one another, reflecting a shift from wet to dry phases. We also looked with finer resolution at the most recent 10-year period, when wetlands have come to dominate the ecosystem owing to a management change, and at individual flood and drought events within years. In space, there is high site fidelity of wetland plant cover, corresponding to reliable water sources. Comparing five-year patterns of plant distribution and stream metabolism between wet and dry years suggested the primacy of geomorphic controls in drought periods. Nutrient limitation of algal production varied from moderate to very strong N limitation, with only one year when there was a (weak) suggestion of secondary P limitation. Over the longer period of record, we identified times characterized by hydrological regime shifts and asked whether ecosystem variables would have changed over that time period. We hypothesized, in particular, that the changes in nutrient status of the stream ecosystem would result from these regime shifts. We used our most complete long-term dataset on stream nitrogen (N) and phosphorus (P) concentrations and N:P ratios as a proxy for nutrient limitation. However, N:P varied primarily at fine scales in response to individual flood events.

  20. Spatio-temporal patterns of stream methane and carbon dioxide emissions in a hemiboreal catchment in Southwest Sweden

    Natchimuthu, Sivakiruthika; Wallin, Marcus B.; Klemedtsson, Leif; Bastviken, David


    Global stream and river greenhouse gas emissions seem to be as large as the oceanic C uptake. However, stream and river emissions are uncertain until both spatial and temporal variability have been quantified. Here we investigated in detail the stream CH4 and CO2 emissions within a hemiboreal catchment in Southwest Sweden primarily covered by coniferous forest. Gas transfer velocities (k600), CH4 and CO2 concentrations were measured with multiple methods. Our data supported modelling approaches accounting for various stream slopes, water velocities and discharge. The results revealed large but partially predictable spatio-temporal variabilities in k600, dissolved gas concentrations, and emissions. The variability in CO2 emission was best explained by the variability in k, while dissolved CH4 concentrations explained most of the variability in CH4 emission, having implications for future measurements. There were disproportionately large emissions from high slope stream reaches including waterfalls, and from high discharge events. In the catchment, stream reaches with low slope and time periods of moderate discharge dominated (90% of area and 69% of time). Measurements in these stream areas and time periods only accounted for <36% of the total estimated emissions. Hence, not accounting for local or episodic high emissions can lead to substantially underestimated emissions.

  1. Beaded streams of Arctic permafrost landscapes

    C. D. Arp


    Full Text Available 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

  2. Summer stream water temperature models for Great Lakes streams: New York

    Murphy, Marilyn K.; McKenna, James E.; Butryn, Ryan S.; McDonald, Richard P.


    Temperature is one of the most important environmental influences on aquatic organisms. It is a primary driver of physiological rates and many abiotic processes. However, despite extensive research and measurements, synoptic estimates of water temperature are not available for most regions, limiting our ability to make systemwide and large-scale assessments of aquatic resources or estimates of aquatic species abundance and biodiversity. We used subwatershed averaging of point temperature measurements and associated multiscale landscape habitat conditions from over 3,300 lotic sites throughout New York State to develop and train artificial neural network models. Separate models predicting water temperature (in cold, cool, and warm temperature classes) within small catchment–stream order groups were developed for four modeling units, which together encompassed the entire state. Water temperature predictions were then made for each stream segment in the state. All models explained more than 90% of data variation. Elevation, riparian forest cover, landscape slope, and growing degree-days were among the most important model predictors of water temperature classes. Geological influences varied among regions. Predicted temperature distributions within stream networks displayed patterns of generally increasing temperature downstream but were patchy due to the averaging of water temperatures within stream size-classes of small drainages. Models predicted coldwater streams to be most numerous and warmwater streams to be generally associated with the largest rivers and relatively flat agricultural areas and urban areas. Model predictions provide a complete, georeferenced map of summer daytime mean stream temperature potential throughout New York State that can be used for planning and assessment at spatial scales from the stream segment class to the entire state.

  3. WATSTORE Stream Flow Basin Characteristics File

    U.S. Geological Survey, Department of the Interior — The Stream Flow Basin Characteristics file contains information about the drainage basins of selected USGS gaging stations. Data elements of this file were converted...

  4. Patterns of macroinvertebrate assemblages in a long-term watershed-scale study to address the effects of pulp and paper mill discharges in four US receiving streams.

    Flinders, Camille A; Minshall, G Wayne; Ragsdale, Renee L; Hall, Timothy J


    Changes in macroinvertebrate communities exposed to pulp and paper mill effluent (PPME) have been seen in mesocosm and short-term field studies. However, long-term patterns of macroinvertebrates in PPME receiving streams have not been examined. We conducted a study of 4 PPME receiving streams (Codorus Creek, PA; the Leaf River, MS; and the McKenzie and Willamette rivers, OR) over 9 y to assess temporal patterns in macroinvertebrate community structure and metrics related to PPME discharge. Study streams represented different ecoregions, warm-/cold-water systems, gradients of PPME concentration (mill process types. Bray-Curtis similarity and nonmetric multidimensional scaling showed significant community differences across sites in Codorus Creek, but differences were related to stream temperature patterns and not PPME. In the other study streams, seasonal community differences across years were greater than differences across sites. General linear models were used to examine spatial and temporal variation in macroinvertebrate metric response (% dominant taxa, density, richness, Hilsenhoff Biotic Index [HBI], Simpson's Index, and ash-free dry mass). Mean HBI scores indicated that the macroinvertebrate community reflected fair to very good water quality conditions, with water quality typically classified as "good" at most sites. Significant site differences in macroinvertebrate metric response were uncommon in the Leaf, McKenzie, and Willamette rivers but were seen in all metrics in Codorus Creek, where metric response was spatially variable. In the McKenzie River, there was an increase in mean HBI scores at sites downstream of the mill relative to 1 of the 2 upstream sites. However, significant differences were seen only between 1 upstream and downstream site, and HBI scores at all downstream sites consistently reflected "good" water quality. Significant annual differences in metric response were typical in all rivers. Water quality (pH, conductivity, total nitrogen

  5. CO2 and CH4 emissions from streams in a lake-rich landscape: Patterns, controls, and regional significance

    Crawford, John T.; Lottig, Noah R.; Stanley, Emily H.; Walker, John F.; Hanson, Paul C.; Finlay, Jacques C.; Striegl, Robert G.


    Aquatic ecosystems are important components of landscape carbon budgets. In lake-rich landscapes, both lakes and streams may be important sources of carbon gases (CO2 and CH4) to the atmosphere, but the processes that control gas concentrations and emissions in these interconnected landscapes have not been adequately addressed. We use multiple data sets that vary in their spatial and temporal extent during 2001-2012 to investigate the carbon gas source strength of streams in a lake-rich landscape and to determine the contribution of lakes, metabolism, and groundwater to stream CO2 and CH4. We show that streams emit roughly the same mass of CO2 (23.4 Gg C yr-1; 0.49 mol CO2 m-2 d-1) as lakes at a regional scale (27 Gg C yr-1) and that stream CH4 emissions (189 Mg C yr-1; 8.46 mmol CH4 m-2 d-1) are an important component of the regional greenhouse gas balance. Gas transfer velocity variability (range = 0.34 to 13.5 m d-1) contributed to the variability of gas flux in this landscape. Groundwater inputs and in-stream metabolism control stream gas supersaturation at the landscape scale, while carbon cycling in lakes and deep groundwaters does not control downstream gas emissions. Our results indicate the need to consider connectivity of all aquatic ecosystems (lakes, streams, wetlands, and groundwater) in lake-rich landscapes and their connections with the terrestrial environment in order to understand the full nature of the carbon cycle.

  6. River piracy and drainage basin reorganization led by climate-driven glacier retreat

    Shugar, Daniel H.; Clague, John J.; Best, James L.; Schoof, Christian; Willis, Michael J.; Copland, Luke; Roe, Gerard H.


    River piracy--the diversion of the headwaters of one stream into another one--can dramatically change the routing of water and sediment, with a profound effect on landscape evolution. Stream piracy has been investigated in glacial environments, but so far it has mainly been studied over Quaternary or longer timescales. Here we document how retreat of Kaskawulsh Glacier--one of Canada's largest glaciers--abruptly and radically altered the regional drainage pattern in spring 2016. We use a combination of hydrological measurements and drone-generated digital elevation models to show that in late May 2016, meltwater from the glacier was re-routed from discharge in a northward direction into the Bering Sea, to southward into the Pacific Ocean. Based on satellite image analysis and a signal-to-noise ratio as a metric of glacier retreat, we conclude that this instance of river piracy was due to post-industrial climate change. Rapid regional drainage reorganizations of this type can have profound downstream impacts on ecosystems, sediment and carbon budgets, and downstream communities that rely on a stable and sustained discharge. We suggest that the planforms of Slims and Kaskawulsh rivers will adjust in response to altered flows, and the future Kaskawulsh watershed will extend into the now-abandoned headwaters of Slims River and eventually capture the Kluane Lake drainage.

  7. Seasonal patterns in nutrients, carbon, and algal responses in wadeable streams within three geographically distinct areas of the United States, 2007-08

    Lee, Kathy E.; Lorenz, David L.; Petersen, James C.; Greene, John B.


    The U.S. Geological Survey determined seasonal variability in nutrients, carbon, and algal biomass in 22 wadeable streams over a 1-year period during 2007 or 2008 within three geographically distinct areas in the United States. The three areas are the Upper Mississippi River Basin (UMIS) in Minnesota, the Ozark Plateaus (ORZK) in southern Missouri and northern Arkansas, and the Upper Snake River Basin (USNK) in southern Idaho. Seasonal patterns in some constituent concentrations and algal responses were distinct. Nitrate concentrations were greatest during the winter in all study areas potentially because of a reduction in denitrification rates and algal uptake during the winter, along with reduced surface runoff. Decreases in nitrate concentrations during the spring and summer at most stream sites coincided with increased streamflow during the snowmelt runoff or spring storms indicating dilution. The continued decrease in nitrate concentrations during summer potentially is because of a reduction in nitrate inputs (from decreased surface runoff) or increases in biological uptake. In contrast to nitrate concentrations, ammonia concentrations varied among study areas. Ammonia concentration trends were similar at UMIS and USNK sampling sites with winter peak concentrations and rapid decreases in ammonia concentrations by spring or early summer. In contrast, ammonia concentrations at OZRK sampling sites were more variable with peak concentrations later in the year. Ammonia may accumulate in stream water in the winter under ice and snow cover at the UMIS and USNK sites because of limited algal metabolism and increased mineralization of decaying organic matter under reducing conditions within stream bottom sediments. Phosphorus concentration patterns and the type of phosphorus present changes with changing hydrologic conditions and seasons and varied among study areas. Orthophosphate concentrations tended to be greater in the summer at UMIS sites, whereas total

  8. Influences of the land use pattern on water quality in low-order streams of the Dongjiang River basin, China: A multi-scale analysis.

    Ding, Jiao; Jiang, Yuan; Liu, Qi; Hou, Zhaojiang; Liao, Jianyu; Fu, Lan; Peng, Qiuzhi


    Understanding the relationships between land use patterns and water quality in low-order streams is useful for effective landscape planning to protect downstream water quality. A clear understanding of these relationships remains elusive due to the heterogeneity of land use patterns and scale effects. To better assess land use influences, we developed empirical models relating land use patterns to the water quality of low-order streams at different geomorphic regions across multi-scales in the Dongjiang River basin using multivariate statistical analyses. The land use pattern was quantified in terms of the composition, configuration and hydrological distance of land use types at the reach buffer, riparian corridor and catchment scales. Water was sampled under summer base flow at 56 low-order catchments, which were classified into two homogenous geomorphic groups. The results indicated that the water quality of low-order streams was most strongly affected by the configuration metrics of land use. Poorer water quality was associated with higher patch densities of cropland, orchards and grassland in the mountain catchments, whereas it was associated with a higher value for the largest patch index of urban land use in the plain catchments. The overall water quality variation was explained better by catchment scale than by riparian- or reach-scale land use, whereas the spatial scale over which land use influenced water quality also varied across specific water parameters and the geomorphic basis. Our study suggests that watershed management should adopt better landscape planning and multi-scale measures to improve water quality.

  9. Mercury mine drainage and processes that control its environmental impact

    Rytuba, J.J.


    Mine drainage from mercury mines in the California Coast Range mercury mineral belt is an environmental concern because of its acidity and high sulfate, mercury, and methylmercury concentrations. Two types of mercury deposits are present in the mineral belt, silica-carbonate and hot-spring type. Mine drainage is associated with both deposit types but more commonly with the silica-carbonate type because of the extensive underground workings present at these mines. Mercury ores consisting primarily of cinnabar were processed in rotary furnaces and retorts and elemental mercury recovered from condensing systems. During the roasting process mercury phases more soluble than cinnabar are formed and concentrated in the mine tailings, commonly termed calcines. Differences in mineralogy and trace metal geochemistry between the two deposit types are reflected in mine drainage composition. Silica-carbonate type deposits have higher iron sulfide content than hot- spring type deposits and mine drainage from these deposits may have extreme acidity and very high concentrations of iron and sulfate. Mercury and methylmercury concentrations in mine drainage are relatively low at the point of discharge from mine workings. The concentration of both mercury species increases significantly in mine drainage that flows through and reacts with calcines. The soluble mercury phases in the calcines are dissolved and sulfate is added such that methylation of mercury by sulfate reducing bacteria is enhanced in calcines that are saturated with mine drainage. Where mercury mine drainage enters and first mixes with stream water, the addition of high concentrations of mercury and sulfate generates a favorable environment for methylation of mercury. Mixing of oxygenated stream water with mine drainage causes oxidation of dissolved iron(II) and precipitation of iron oxyhydroxide that accumulates in the streambed. Both mercury and methylmercury are strongly adsorbed onto iron oxyhydroxide over the p

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

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


    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.

  11. Nutrient sampling slam: high resolution surface-water sampling in streams reveals patterns in groundwater chemistry and flow paths

    The groundwater–surface water interface (GSWI), consisting of shallow groundwater adjacent to stream channels, is a hot spot for nitrogen removal processes, a storage zone for other solutes, and a target for restoration activities. Characterizing groundwater-surface water intera...

  12. Spatial patterns of Pisidium chilense (Mollusca Bivalvia and Hyalella patagonica (Crustacea, Amphipoda in an unpolluted stream in Navarino island (54° S, Cape Horn Biosphere Reserve

    Patricio De Los Ríos Escalante


    Full Text Available The southern South American inland waters have many endemic species and some of them are considered as endangered for IUCN, that inhabits in unpolluted ecosystems, one of these ecosystems are the sub-Antarctic perennial forests located in the Cape Horn Biosphere Reserve at 54° S. The aim of the present study is to analyze the spatial patterns of Pisidium chilense Ituarte, 1999 (Mollusca Bivalvia and Hyalella patagonica (Cunningham, 1871 (Crustacea, Amphipoda in an unpolluted stream. Both species had aggregated spatial distribution, both have a negative binomial distribution pattern, and both are associated. The present results would agree with similar patterns in Patagonian rivers where both species coexist.

  13. Efficient removal of meltwater runoff through supraglacial streams and rivers on the southwestern Greenland Ice Sheet

    Smith, L. C.; Yang, K.; Pitcher, L. H.; Overstreet, B. T.; Rennermalm, A. K.; Chu, V. W.; Ryan, J.; Hubbard, A.; Cooper, M. G.; Tedesco, M.; Mote, T. L.; Young, K.; Behar, A.


    Supraglacial streams and rivers flowing on the Greenland Ice Sheet have received little physical study. We present remotely sensed (UAV, WorldView) and in situ (Acoustic Doppler Current Profiler, Lagrangian drifters) measurements of supraglacial river drainage pattern, hydraulic properties, and discharge in the Kangerlussuaq region. This area of the ice sheet is characterized by large, well-organized supraglacial stream/river networks that efficiently drain the ice surface with minimal retention of surface water, with river moulins being the the dominant physical mechanism by which surface meltwater enters the ice sheet. An intensive 2015 field campaign acquired novel datasets of watershed extent, drainage pattern, ablation rate, albedo and discharge for a ~70 km2 mid-elevation ice catchment ("Rio Behar"), including a continuous 72-hour record of discharge and water temperature in a supraglacial river upstream of its terminal moulin. We conclude that this area of the ice sheet is efficiently drained by supraglacial stream/river networks, that ice-surface DEMs alone cannot fully describe supraglacial drainage and its connection to subglacial systems; and that in situ measurements of supraglacial river discharge offer a unique opportunity to test runoff predictions of regional climate models.

  14. Foam consolidation and drainage.

    Jun, S; Pelot, D D; Yarin, A L


    A theoretical model of foam as a consolidating continuum is proposed. The general model is applied to foam in a gravity settler. It is predicted that liquid drainage from foam in a gravity settler begins with a slow drainage stage. Next, a stage with faster drainage occurs where the drainage rate doubles compared to the initial stage. The experiments conducted within the framework of this work confirmed the theoretical predictions and allowed measurements of foam characteristics. Foams of three different concentrations of Pantene Pro-V Classic Care Solutions shampoo were studied, as well as the addition of polyethylene oxide (PEO) in one case. The shampoo's main foaming components are sodium lauryl sulfate and sodium laureth sulfate. It is shown to what extent foam drainage is slowed down by using higher shampoo concentrations and how it is further decreased by adding polymer (PEO).

  15. Modeling nutrient retention at the watershed scale: Does small stream research apply to the whole river network?

    Aguilera, Rosana; Marcé, Rafael; Sabater, Sergi


    are conveyed from terrestrial and upstream sources through drainage networks. Streams and rivers contribute to regulate the material exported downstream by means of transformation, storage, and removal of nutrients. It has been recently suggested that the efficiency of process rates relative to available nutrient concentration in streams eventually declines, following an efficiency loss (EL) dynamics. However, most of these predictions are based at the reach scale in pristine streams, failing to describe the role of entire river networks. Models provide the means to study nutrient cycling from the stream network perspective via upscaling to the watershed the key mechanisms occurring at the reach scale. We applied a hybrid process-based and statistical model (SPARROW, Spatially Referenced Regression on Watershed Attributes) as a heuristic approach to describe in-stream nutrient processes in a highly impaired, high stream order watershed (the Llobregat River Basin, NE Spain). The in-stream decay specifications of the model were modified to include a partial saturation effect in uptake efficiency (expressed as a power law) and better capture biological nutrient retention in river systems under high anthropogenic stress. The stream decay coefficients were statistically significant in both nitrate and phosphate models, indicating the potential role of in-stream processing in limiting nutrient export. However, the EL concept did not reliably describe the patterns of nutrient uptake efficiency for the concentration gradient and streamflow values found in the Llobregat River basin, posing in doubt its complete applicability to explain nutrient retention processes in stream networks comprising highly impaired rivers.

  16. Physical modeling of transverse drainage mechanisms

    Douglass, J. C.; Schmeeckle, M. W.


    Streams that incise across bedrock highlands such as anticlines, upwarps, cuestas, or horsts are termed transverse drainages. Their relevance today involves such diverse matters as highway and dam construction decisions, location of wildlife corridors, better-informed sediment budgets, and detailed studies into developmental histories of late Cenozoic landscapes. The transient conditions responsible for transverse drainage incision have been extensively studied on a case-by-case basis, and the dominate mechanisms proposed include: antecedence, superimposition, overflow, and piracy. Modeling efforts have been limited to antecedence, and such the specific erosional conditions required for transverse drainage incision, with respect to the individual mechanisms, remains poorly understood. In this study, fifteen experiments attempted to simulate the four mechanisms and constructed on a 9.15 m long, 2.1 m wide, and 0.45 m deep stream table. Experiments lasted between 50 and 220 minutes. The stream table was filled with seven tons of sediment consisting of a silt and clay (30%) and a fine to coarse sand (70%) mixture. The physical models highlighted the importance of downstream aggradation with regard to antecedent incision versus possible defeat and diversion. The overflow experiments indicate that retreating knickpoints across a basin outlet produce a high probability of downstream flooding when associated with a deep lake. Misters used in a couple of experiments illustrate a potential complication with regard to headward erosion driven piracy. Relatively level asymmetrically sloped ridges allow for the drainage divide across the ridge to retreat from headward erosion, but hindered when the ridge's apex undulates or when symmetrically sloped. Although these physical models cannot strictly simulate natural transverse drainages, the observed processes, their development over time, and resultant landforms roughly emulate their natural counterparts. Proposed originally from

  17. Nitrogen patterns in subsurface waters of the Yzeron stream: effect of combined sewer overflows and subsurface-surface water mixing.

    Aucour, A M; Bariac, T; Breil, P; Namour, P; Schmitt, L; Gnouma, R; Zuddas, P


    Urbanization subjects streams to increased nitrogen loads. Therefore studying nitrogen forms at the interface between urban stream and groundwater is important for water resource management. In this study we report results on water δ(18)O and nitrogen forms in subsurface waters of a stream (Yzeron, France). The sites studied were located upstream and downstream of combined sewer overflows (CSO) in a rural area and a periurban area, respectively. Water δ(18)O allowed us to follow the mixing of subsurface water with surface water. Dissolved organic nitrogen and organic carbon of fine sediment increased by 20-30% between rural and periurban subsurface waters in the cold season, under high flow. The highest nitrate levels were observed in rural subsurface waters in the cold season. The lowest nitrate levels were found in periurban subsurface waters in the warm season, under low flow. They corresponded to slow exchange of subsurface waters with channel water. Thus reduced exchange between surface and subsurface waters and organic-matter-rich input seemed to favor nitrate reduction in the downstream, periurban, subsurface waters impacted by CSO.

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

    CERN. Geneva


    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 ...

  19. Application of digital elevation model in delineating drainage networks

    SUN Yan-ling; XIE De-ti; LIU Hong-bin; WEI Chao-fu


    A practical method to extract drainage network from DEM (digital elevation model) is introduced. DEM pretreatment includes depression and flat areas treatment. The flow direction of each grid cell in DEM is calculated according to the 8-direction pour point model, and then the flow accumulation grid from the flow direction grid. With the flow accumulation grid, streams are defined according to the given threshold value of flow accumulation. Taking Gufo River watershed as an example, the extraction of drainage network was done from DEM. The results are basically consistent with the digitized drainage network from the relief maps.

  20. Topological Analysis of Urban Drainage Networks

    Yang, Soohyun; Paik, Kyungrock; McGrath, Gavan; Rao, Suresh


    Urban drainage networks are an essential component of infrastructure, and comprise the aggregation of underground pipe networks carrying storm water and domestic waste water for eventual discharge to natural stream networks. Growing urbanization has contributed to rapid expansion of sewer networks, vastly increasing their complexity and scale. Importance of sewer networks has been well studied from an engineering perspective, including resilient management, optimal design, and malfunctioning impact. Yet, analysis of the urban drainage networks using complex networks approach are lacking. Urban drainage networks consist of manholes and conduits, which correspond to nodes and edges, analogous to junctions and streams in river networks. Converging water flows in these two networks are driven by elevation gradient. In this sense, engineered urban drainage networks share several attributes of flows in river networks. These similarities between the two directed, converging flow networks serve the basis for us to hypothesize that the functional topology of sewer networks, like river networks, is scale-invariant. We analyzed the exceedance probability distribution of upstream area for practical sewer networks in South Korea. We found that the exceedance probability distributions of upstream area follow power-law, implying that the sewer networks exhibit topological self-similarity. The power-law exponents for the sewer networks were similar, and within the range reported from analysis of natural river networks. Thus, in line with our hypothesis, these results suggest that engineered urban drainage networks share functional topological attributes regardless of their structural dissimilarity or different underlying network evolution processes (natural vs. engineered). Implications of these findings for optimal design of sewer networks and for modeling sewer flows will be discussed.

  1. Hyporheic flow pattern based on the coupling of regional and stream scales: Case of Krycklan Catchment area

    Mojarrad, Morteza; Wörman, Anders; Riml, Joakim


    Water resources intense development within the past century has had an enormous impact on hydrological systems especially on rivers and groundwater resources. A river basin is a flow system involving the interaction between surface water and groundwater. This interaction occurs in terrestrial and coastal zone and even in arid and semi-arid areas, where surface water overlie on a permeable sediment. A key zone for the interaction between surface water and groundwater is the hyporheic zone, which forms by stream water that in- and exfiltrating in the permeable sediments surrounding the river corridor. Groundwater and hyporheic flows arise due to different range of topographical scales and their relative importance is investigated in this study. Krycklan is a well-monitored research catchment in which the data collection for more than 90 years has comprised hydrology, biochemistry, and aquatic ecology. The catchment is located in a boreal area of northern Sweden. The head-water streams begin in mountainous area and fall to the Baltic Sea near the city of Umea. In this paper, COMSOL Multi-physics simulation software has been used to model the subsurface flow of the whole Krycklan catchment in order to reach a comprehensive understanding of large-scale groundwater circulation and its impact of the stream hyporheic flows. The model statement is based on the 3D Laplace equation, which has been applied independently on two ranges of topographical scales to obtain a superimposed solution. Steady state simulation has been done based on the simplified assumption of constant boundary conditions of the groundwater surface and otherwise non-flow boundaries. The hydraulic head of the groundwater surface was taken as the topography, which apply as an approximation in wet climate with shallow soil layers. The results demonstrated how the ratio of the topographical amplitudes on different scales affect the size (depth) and fragmentation of the hyporheic zone. "Fragmentation" was

  2. Lymphoscintigraphy and SPECT/CT in multicentric and multifocal breast cancer: does each tumour have a separate drainage pattern? Results of a Dutch multicentre study (MULTISENT)

    Brouwer, O.R. [Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Netherlands Cancer Institute, Amsterdam (Netherlands); Antoni van Leeuwenhoekhospital, Amsterdam (Netherlands); Vermeeren, L.; Valdes Olmos, R.A. [Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Netherlands Cancer Institute, Amsterdam (Netherlands); Ploeg, I.M.C. van der; Rutgers, E.J.T.; Oldenburg, H.S.A. [Antoni van Leeuwenhoek Hospital, Department of Surgery, Netherlands Cancer Institute, Amsterdam (Netherlands); Loo, C.E. [Antoni van Leeuwenhoek Hospital, Department of Radiology, Netherlands Cancer Institute, Amsterdam (Netherlands); Pereira-Bouda, L.M.; Smit, F. [Rijnland Hospital, Department of Nuclear Medicine, Leiderdorp (Netherlands); Neijenhuis, P. [Rijnland Hospital, Department of Surgery, Leiderdorp (Netherlands); Vrouenraets, B.C. [Sint Lucas Andreas Hospital, Department of Surgery, Amsterdam (Netherlands); Sivro-Prndelj, F. [Sint Lucas Andreas Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands); Jap-a-Joe, S.M.; Borgstein, P.J. [Onze Lieve Vrouwe Gasthuis, Department of Nuclear Medicine, Amsterdam (Netherlands)


    To investigate whether lymphoscintigraphy and SPECT/CT after intralesional injection of radiopharmaceutical into each tumour separately in patients with multiple malignancies in one breast yields additional sentinel nodes compared to intralesional injection of the largest tumour only. Patients were included prospectively at four centres in The Netherlands. Lymphatic flow was studied using planar lymphoscintigraphy and SPECT/CT until 4 h after administration of {sup 99m}Tc-nanocolloid in the largest tumour. Subsequently, the smaller tumour(s) was injected intratumorally followed by the same imaging sequence. Sentinel nodes were intraoperatively localized using a gamma ray detection probe and vital blue dye. Included in the study were 50 patients. Additional lymphatic drainage was depicted after the second and/or third injection in 32 patients (64 %). Comparison of planar images and SPECT/CT images after consecutive injections enabled visualization of the number and location of additional sentinel nodes (32 axillary, 11 internal mammary chain, 2 intramammary, and 1 interpectoral. A sentinel node contained metastases in 17 patients (34 %)). In five patients with a tumour-positive node in the axilla that was visualized after the first injection, an additional involved axillary node was found after the second injection. In two patients, isolated tumour cells were found in sentinel nodes that were only visualized after the second injection, whilst the sentinel nodes identified after the first injection were tumour-negative. Lymphoscintigraphy and SPECT/CT after consecutive intratumoral injections of tracer enable lymphatic mapping of each tumour separately in patients with multiple malignancies within one breast. The high incidence of additional sentinel nodes draining from tumours other than the largest one suggests that separate tumour-related tracer injections may be a more accurate approach to mapping and sampling of sentinel nodes in patients with multicentric or

  3. Streams with Strahler Stream Order

    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...

  4. Agricultural Drainage Well Intakes

    Iowa State University GIS Support and Research Facility — Locations of surface intakes for registered agriculture drainage wells according to the database maintained by IDALS. Surface intakes were located from their...

  5. Surface Water & Surface Drainage

    Earth Data Analysis Center, University of New Mexico — This data set contains boundaries for all surface water and surface drainage for the state of New Mexico. It is in a vector digital data structure digitized from a...

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

    V. Wennrich


    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.

  7. Patterns of Batrachochytrium dendrobatidis transmission between tadpoles in a high-elevation rainforest stream in tropical Australia.

    Hagman, Mattias; Alford, Ross A


    The highly virulent fungal pathogen Batrachochytrium dendrobatidis (Bd) poses a global threat to amphibian biodiversity. Streams and other water bodies are central habitats in the ecology of the disease, particularly in rainforests where they may transport and transmit the pathogen and harbor infected tadpoles that serve as reservoir hosts. We conducted an experiment using larval green-eyed tree frogs Litoria serrata in semi-natural streamside channels to test the hypotheses that (1) the fungus can be transmitted downstream in stream habitats and (2) infection affects tadpole growth and mouthpart loss. Our results showed that transmission can occur downstream in flowing water with no contact between individuals, that newly infected tadpoles suffered increased mouthpart loss in comparison with controls that were never infected and that infected tadpoles grew at reduced rates. Although recently infected tadpoles showed substantial loss of mouthparts, individuals with longstanding infections did not, suggesting that mouthparts may re-grow following initial loss. Our study suggests that any management efforts that can reduce the prevalence of infections in tadpoles may be particularly effective if applied in headwater areas, as their effects are likely to be felt downstream.

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

    V. Wennrich


    Full Text Available High Arctic 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-precipitaion of these elements with Fe and Mn hydroxides and oxides. But the akin distribution of organic matter content might also point to a fixation to organic components. 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 in-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.


    章一超; 陈凯; 梁阿磊; 白英彩; 管海兵


    As a stream processor, GPU is widely used in general high-performance computation, and no longer limited to the image processing area only. NVDIA CUDA and AMD Stream SDK are popular stream programming environments for General-Purpose computation on GPU ( GPGPU). However both of them have shortcomings and limitations. The biggest problems are the shortage of binary compatibility which is confronting different GPUs and the large cost in rewriting existing source codes. By using binary analysis and dynamic binary translation technology the article implements an automatic execution framework,GxBit, which offers a method to extract stream patterns from x86 binary programs to be mapped into NVIDIA CUDA programming environment. Validated by multiple programs from CUDA SDK Sample and Parboil Benchmark Suite,the framework upgrades the performance to an average level of 10 times.%图形处理单元(GPU)作为一种流体系结构的处理器,现已被广泛地用于通用高性能计算,而不仅仅局限于图像处理领域了.NVIDIA的CUDA和AMD的Stream SDK都是现在比较流行的针对GPU通用计算(GPGPU)的流编程环境.然而,它们有自身的缺陷和限制,其中最主要的便是缺乏面对不同GPU的二进制兼容性问题和重写已有程序源代码代价大的问题.通过利用二进制分析和动态二进制翻译技术,实现一个自动化执行框架GxBit,它提供一种从x86二进制程序中提取流模式,并映射到NVIDIACUDA编程环境的方法.该框架经过CUDA SDK Sample和Parboil Benchmark Suite中若干程序的验证,平均取得10倍以上的性能提升.

  10. Airport Pavement Drainage


    drainage layer and trench drains can be found in Cedergren (10). 4.2 COMPONENTS OF SUBSURFACE DRAINAGE SYSTEM 4.2.1 Outflow Once the water has found...According to Cedergren (10) the open graded aggregate can replace the normally used dense graded materials on an inch-for-inch basis. A main problem in...the perforated pipe to prevent fines from entering, Figure 4.24 (11). Cedergren (10) suggests that collector pipes should be 42 laid with the

  11. [Characteristics and Transport Patterns of Ammonia, Nitrites, Nitrates and Inorganic Nitrogen Flux at Epikarst Springs and a Subterranean Stream in Nanshan, Chongqing].

    Zhang, Yuan-zhu; He, Qiu-fang; Jiang, Yong-jun; Li, Yong


    In a karst groundwater system, it develops complex multiple flows because of its special geological structure and unique physical patterns of aquifers. In order to investigate the characteristics and transport patterns of ammonia, nitrite and nitrate in epikarst water and subterranean stream, the water samples were collected monthly in a fast-urbanizing karst region. The results showed distinctive characteristics of three forms of inorganic nitrogen. The concentration of inorganic nitrogen was stable in the epikarst water while it was fluctuant in the subterranean stream. Epikarst water was less affected by rainfall and sewage compared with subterranean stream. In epikarst water, the nitrate concentration was much higher than the ammonia concentration. Dissolved inorganic nitrogen, mainly from non-point source pollution related to agricultural activities, passed in and out of the epikarst water based on a series of physical; chemical and biological processes in the epikarst zone, such as ammonification, adsorption and nitrification. On the contrary, subterranean stream showed a result of NH₄⁺-N > NO₃⁻-N in dry seasons and NO₃⁻-N > NH₄⁺-N in rainy seasons. This can be due to the fact that sanitary and industrial sewage flowed into subterranean river through sinkholes, fissures and grikes in dry season. Dissolved inorganic nitrogen in subterranean river was mainly from the non-point source pollution in wet season. Non-point source pollutants entered into subterranean water by two transport ways, one by penetration along with vadose flow through fissures and grikes, and the other by conduit flow through sinkholes from the surface runoff, soil water flow and epikarst flow. The export flux of DIN was 56.05 kg · (hm² · a)⁻¹, and NH₄⁺-N and NO₃⁻-N accounted for 46.03% and 52.51%, respectively. The contributions of point-source pollution and non point-source pollution to the export flux of DIN were 25.08% and 74.92%, respectively, based on run

  12. Relations among geology, physiography, land use, and stream habitat conditions in the Buffalo and Current River Systems, Missouri and Arkansas

    Panfil, Maria S.; Jacobson, Robert B.


    This study investigated links between drainage-basin characteristics and stream habitat conditions in the Buffalo National River, Arkansas and the Ozark National Scenic Riverways, Missouri. It was designed as an associative study - the two parks were divided into their principle tributary drainage basins and then basin-scale and stream-habitat data sets were gathered and compared between them. Analyses explored the relative influence of different drainage-basin characteristics on stream habitat conditions. They also investigated whether a relation between land use and stream characteristics could be detected after accounting for geologic and physiographic differences among drainage basins. Data were collected for three spatial scales: tributary drainage basins, tributary stream reaches, and main-stem river segments of the Current and Buffalo Rivers. Tributary drainage-basin characteristics were inventoried using a Geographic Information System (GIS) and included aspects of drainage-basin physiography, geology, and land use. Reach-scale habitat surveys measured channel longitudinal and cross-sectional geometry, substrate particle size and embeddedness, and indicators of channel stability. Segment-scale aerial-photo based inventories measured gravel-bar area, an indicator of coarse sediment load, along main-stem rivers. Relations within and among data sets from each spatial scale were investigated using correlation analysis and multiple linear regression. Study basins encompassed physiographically distinct regions of the Ozarks. The Buffalo River system drains parts of the sandstone-dominated Boston Mountains and of the carbonate-dominated Springfield and Salem Plateaus. The Current River system is within the Salem Plateau. Analyses of drainage-basin variables highlighted the importance of these physiographic differences and demonstrated links among geology, physiography, and land-use patterns. Buffalo River tributaries have greater relief, steeper slopes, and more

  13. Conservation implications of amphibian habitat relationships within channelized agricultural headwater streams in the midwestern United States

    The widespread use of stream channelization and subsurface tile drainage for removing water from agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States. Channelized agricultural headwater s...

  14. Influence of instream habitat and water chemistry on amphibians within channelized agricultural headwater streams

    The widespread use of stream channelization and subsurface tile drainage for draining agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States, Canada, and Europe. Channelized agricultural he...

  15. Effect of two Gulf Stream warm-core rings on distribution patterns of the diatom genus Nitzschia

    Kaczmarska, Irena; Fryxell, Greta A.; Watkins, T. Phillip


    Two Gulf Stream warm-core rings (WCR) of different ages, 81-D and 82-H, were studied in early autumn of sequential years for the composition and distribution of the pennate diatom genus Nitzschia. The results indicate that species of this genus were dynamic and abundant elements of the diatom flora of the two WCR's, ranging from 33 to 82% of all diatoms in net samples and from 22 to 49% of all diatoms in cell numbers integrated throughout the water column from discrete water bottle samples. A new species, N. lodicula Kaczmarska, was present in both rings and is described. There were 29 species of Nitzschia in the net samples, with a mean of 16 and range of 8-22 in any one net haul. Two different types of assemblages characterized the two rings of different maturity. The first type was dominated by N. bicapitata Cleve and the second by N. bifurcata Kaczmarska & Licea. Nitzschia bifurcata was more abundant in the just-forming WCR 82-H, similar to the Gulf Stream sample collected the previous month before ring formation. N bicapitata was more abundant in the 3-month-old WCR 81-D, which may indicate influence of the water masses by coastal flora. Diverse assemblages, including representatives of the section Pseudonitzschia were found in the Sargasso Sea and in the Slope Water, but they differed markedly from each other. The assemblages of Nitzschia indicate that the Gulf Stream was probably a primary source of these WCR water masses. The changes in abundance in relation to other phytoplankton indicate that the genus is not opportunistic in taking advantage of overturns in the water column. Rather it survives well in stressful situations such as the High Velocity Region or during periods of ring overwash by Slope Wate, when other cell numbers are low. This study supports the concept of WCR as a flattening bowl or disc-shaped body that responds within hours to internal overturns and incorporation of Slope Water streamers.

  16. Influence of mine drainage on water quality along River Nyaba in ...


    and coal refuse piles is the oldest industrial pollution in the Enugu coal area which ... heaps into soils, surface water and groundwater as well as into stream ...... natural attenuation of arsenic in drainage from an abandoned arsenic mine dump.

  17. Drainage Basins used for Development of the Watershed Regressions for Pesticides (WARP) Model

    U.S. Geological Survey, Department of the Interior — This data set consists of 204 drainage basin boundaries for U.S. Geological Survey's (USGS) stream sites sampled in the National Water Quality Assessment (NAWQA)...

  18. Drainage Basins used for Development of the Watershed Regressions for Pesticides (WARP) Model, 2012

    U.S. Geological Survey, Department of the Interior — This data set contains 204 drainage basin boundaries for U.S. Geological Survey (USGS) stream sites analyzed in the Watershed Regressions for Pesticides (WARP)...

  19. Modeling Antarctic subglacial lake filling and drainage cycles

    C. F. Dow


    Full Text Available The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to determine internal controls on the filling and drainage of subglacial lakes and their impact on ice stream dynamics. Our model outputs suggest that the highly constricted subglacial environment of the ice stream, combined with relatively high rates of water flow funneled from large catchments, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water through the ice stream drives lake growth. As the water body builds up, it too steepens the hydraulic gradient and allows greater flux out of the overdeepened lake basin. Eventually this flux is large enough to create channels that cause the lake to drain. Due to the presence of the channels, the drainage of the lake causes high water pressures around 50 km downstream of the lake rather than immediately in the vicinity of the overdeepening. Following lake drainage, channels again shut down. Lake drainage depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

  20. Use of Natural and Applied Tracers to Guide Targeted Remediation Efforts in an Acid Mine Drainage System, Colorado Rockies, USA

    Rory Cowie; Mark W. Williams; Mike Wireman; Robert L. Runkel


    Stream water quality in areas of the western United States continues to be degraded by acid mine drainage (AMD), a legacy of hard-rock mining. The Rico-Argentine Mine in southwestern Colorado consists of complex multiple-level mine workings connected to a drainage tunnel discharging AMD to passive treatment ponds that discharge to the Dolores River. The mine workings are excavated into the hillslope on either side of a tributary stream with workings passing directly under the stream channel. ...

  1. Montana StreamStats


    About this volumeMontana StreamStats is a Web-based geographic information system ( application that provides users with access to basin and streamflow characteristics for gaged and ungaged streams in Montana. Montana StreamStats was developed by the U.S. Geological Survey (USGS) in cooperation with the Montana Departments of Transportation, Environmental Quality, and Natural Resources and Conservation. The USGS Scientific Investigations Report consists of seven independent but complementary chapters dealing with various aspects of this effort.Chapter A describes the Montana StreamStats application, the basin and streamflow datasets, and provides a brief overview of the streamflow characteristics and regression equations used in the study. Chapters B through E document the datasets, methods, and results of analyses to determine streamflow characteristics, such as peak-flow frequencies, low-flow frequencies, and monthly and annual characteristics, for USGS streamflow-gaging stations in and near Montana. The StreamStats analytical toolsets that allow users to delineate drainage basins and solve regression equations to estimate streamflow characteristics at ungaged sites in Montana are described in Chapters F and G.

  2. Parameterizing sub-surface drainage with geology to improve modeling streamflow responses to climate in data limited environments

    C. L. Tague


    Full Text Available Hydrologic models are one of the core tools used to project how water resources may change under a warming climate. These models are typically applied over a range of scales, from headwater streams to higher order rivers, and for a variety of purposes, such as evaluating changes to aquatic habitat or reservoir operation. Most hydrologic models require streamflow data to calibrate subsurface drainage parameters. In many cases, long-term gage records may not be available for calibration, particularly when assessments are focused on low order stream reaches. Consequently, hydrologic modeling of climate change impacts is often performed in the absence of sufficient data to fully parameterize these hydrologic models. In this paper, we assess a geologic-based strategy for assigning drainage parameters. We examine the performance of this modeling strategy for the McKenzie River watershed in the US Oregon Cascades, a region where previous work has demonstrated sharp contrasts in hydrology based primarily on geological differences between the High and Western Cascades. Based on calibration and verification using existing streamflow data, we demonstrate that: (1 a set of streams ranging from 1st to 3rd order within the Western Cascade geologic region can share the same drainage parameter set, and (2 streams from the High Cascade geologic region, however, require a distinctive parameter set. Further, we show that a watershed comprised of a mixture of High and Western Cascade geology can be modeled without additional calibration by transferring parameters from these distinctive High and Western Cascade end-member parameter sets. Using this geologically-based parameter transfer scheme, our model predictions for all watersheds capture dominant historic streamflow patterns, and are sufficiently accurate to resolve geo-climatic differences in how these different watersheds are likely to respond to simple warming scenarios.

  3. Examining spatial patterns in polycyclic aromatic compounds measured in stream macroinvertebrates near a small subarctic oil and gas operation.

    Korosi, J B; Eickmeyer, D C; Chin, K S; Palmer, M J; Kimpe, L E; Blais, J M


    The Cameron River runs through a small, remote petrochemical development in the Cameron Hills (Northwest Territories, Canada). In order to evaluate the exposure of aquatic biota to contaminants from oil and gas activities, we measured polycyclic aromatic compounds (PACs) in macroinvertebrates collected from sites and tributaries along the Cameron River, including upstream and downstream of the development, and sites located near drilled wells (developed). Macroinvertebrate tissue PAC burdens ranged from 0.2-2.8 μg g(-1) lipid for unsubstituted compounds, and from 4.2-63.2 μg g(-1) lipid for alkylated compounds, relatively low compared to similar studies from more industrialized regions in North America. There was no significant difference in tissue PAC burdens between upstream, downstream, or developed sites (p = 0.12), although alkyl PACs in five out of seven developed sites were higher than the regional average. Petrogenic PACs were dominant in most samples, including alkyl fluorines, alkyl phenanthrene/anthracenes, and alkyl dibenzothiophenes. Minimal changes in PAC composition in macroinvertebrate tissues were detected along the Cameron River, with the exception of the two sites furthest downstream that had high concentrations of C3-C4 naphthalene. Overall, our results suggest that oil and gas development in the Cameron Hills has not resulted in substantial increases in PAC bioaccumulation in stream macroinvertebrates, although the potential that alkyl naphthalenes are being transported downstream from the development warrants further attention.

  4. Evidence that local land use practices influence regional climate, vegetation, and stream flow patterns in adjacent natural areas

    Stohlgren, T.J.; Chase, T.N.; Pielke, R.A.; Kittel, T.G.F.; Baron, J.S.


    We present evidence that land use practices in the plains of Colorado influence regional climate and vegetation in adjacent natural areas in the Rocky Mountains in predictable ways. Mesoscale climate model simulations using the Colorado State University Regional Atmospheric Modelling System (RAMS) projected that modifications to natural vegetation in the plains, primarily due to agriculture and urbanization, could produce lower summer temperatures in the mountains. We corroborate the RAMS simulations with three independent sets of data: (i) climate records from 16 weather stations, which showed significant trends of decreasing July temperatures in recent decades; (ii) the distribution of seedlings of five dominant conifer species in Rocky Mountain National Park, Colorado, which suggested that cooler, wetter conditions occurred over roughly the same time period; and (iii) increased stream flow, normalized for changes in precipitation, during the summer months in four river basins, which also indicates cooler summer temperatures and lower transpiration at landscape scales. Combined, the mesoscale atmospheric/land-surface model, short-term in regional temperatures, forest distribution changes, and hydrology data indicate that the effects of land use practices on regional climate may overshadow larger-scale temperature changes commonly associated with observed increases in CO2 and other greenhouse gases.

  5. Evaluation of Catrosat 1PAN Stereo and Resourcesat Liss 4 MSS Merged Data for Morphometric Analysis, Delineation of Drainage Basins and Codification in Tamil Nadu, India and Australia

    Mohamed, G. S.; Srinivasan, S.; Pandian, R.; Gummidipoondi, R. J.; Venkatchalam, R. V.; Swaminathan. S, S.


    interpretation in conjunction with village cadastral maps has been studied. This research will be useful to consider creation of digital micro watershed atlas for management and protecting area affected by floods as well as for water and land resource management of the River basins in Queensland, New South Wales, South Australia and Victoria states of Australia. The research explains the need of using stream orders, delineation and codification micro watersheds based the principles of Dr.A.N.Khosla. This methodology was used in creation of web site of Districts soil water sheds atlas of Tamil Nadu state. With this principal of codification and delineation of watersheds based on stream order using stereo data of Cartosat 1 PAN 2.5 m data merged with Resourcesat LISS 4 data of 5.5m resolution and updating latest changes as on 2011 with non stereo Geo eye data of 0.5m resolution it is possible to create Australian micro water sheds GIS with deatils of streams with various stream orders, drainage pattern, slope, micro water sheds boundary in 1:5000 scale to manage the flood prone drainage basin in Australia. The High resolution data of satellites data apart from creation Micro watersheds GIS can be used for creation of Urban and Argicultural land parcel owenership details in Micro watershed GIS.


    G. S. Mohamed


    as well as visual interpretation in conjunction with village cadastral maps has been studied. This research will be useful to consider creation of digital micro watershed atlas for management and protecting area affected by floods as well as for water and land resource management of the River basins in Queensland, New South Wales, South Australia and Victoria states of Australia. The research explains the need of using stream orders, delineation and codification micro watersheds based the principles of Dr.A.N.Khosla. This methodology was used in creation of web site of Districts soil water sheds atlas of Tamil Nadu state. With this principal of codification and delineation of watersheds based on stream order using stereo data of Cartosat 1 PAN 2.5 m data merged with Resourcesat LISS 4 data of 5.5m resolution and updating latest changes as on 2011 with non stereo Geo eye data of 0.5m resolution it is possible to create Australian micro water sheds GIS with deatils of streams with various stream orders, drainage pattern, slope, micro water sheds boundary in 1:5000 scale to manage the flood prone drainage basin in Australia. The High resolution data of satellites data apart from creation Micro watersheds GIS can be used for creation of Urban and Argicultural land parcel owenership details in Micro watershed GIS.

  7. Drainage of the ice-dammed Lake Tinninilik, West Greenland; implication on bedrock uplift

    Kjeldsen, Kristian Kjellerup; Khan, Shfaqat Abbas; Bjørk, Anders Anker;

    Drainage of ice-dammed lakes is regularly observed along the margin of the Greenland Ice Sheet. However, the speed of the drainage events and implications can vary depending on the size of the lakes and the local settings. Here, we assess the drainage pattern of Lake Tinninilik, dammed...

  8. Estimating magnitude and frequency of floods for Wisconsin urban streams

    Conger, D.H.


    Equations for estimating magnitude and frequency of floods for Wisconsin streams with drainage basins containing various amounts of existing or projected urban development were developed by flood-frequency and multiple-regression analyses.

  9. Analyzing indicators of stream health for Minnesota streams

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


    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.

  10. Concentration-discharge relationships for variably sized streams in Florida: Patterns and drivers in long-term catchment studies

    Diamond, J.; Cohen, M.


    Catchment-scale analyses can provide important insight into the processes governing solute sources, transport and storage. Understanding solute dynamics is vital for water management both for accurate predictions of chemical fluxes as well as ecosystem responses to them. This project synthesized long-term (>15 years) hydrochemical data from 80 variably sized (101-105 m2) watersheds in Florida. Our goal was to evaluate scaling effects on flow-solute relationships, and determine the factors that control observed inter-catchment variation. We obtained long term records of a variety of chemical parameters include color, nutrients (N and P), and geogenic solutes (Ca, Si, Mg, Na, Cl) from stations where chemistry and flow data were matched. Catchment attributes (land use, terrain, surface geology) were obtained for each stream as potential covariates. Concentration-discharge relationships were modeled as power functions, the exponents (b) of which were categorized into three end-member scenarios: (1) b>0, or chemodynamic conditions, where increased discharge increases concentration, (2) b=0, or chemostatic conditions, where concentration is independent of discharge, and (3) b<0, or dilution conditions, where increased discharge decreases concentrations. Color was strongly chemodynamic, while geogenic solutes tended to be chemostatic;nutrient-flow relationships varied substantially (from dilution to chemodynamic) suggesting important ancillary controls. To assess between-site variability, power function exponents were compared against land use and catchment area. These results indicate that watersheds dominated by urban land use exhibit stronger dilution effects for most solutes while watersheds dominated by agricultural land use were generally chemostatic particularly for nutrients. This synthesis approach to understanding controls on observed concentration-discharge relationships is crucial to understanding the dynamics and early-warning indicators of anthropogenically

  11. Modeling Antarctic Subglacial Lake Filling and Drainage Cycles

    Dow, Christine F.; Werder, Mauro A.; Nowicki, Sophie; Walker, Ryan T.


    The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to examine internal controls on the filling and drainage of subglacial lakes. Our model outputs suggest that the highly constricted subglacial environment of our idealized ice stream, combined with relatively high rates of water flow funneled from a large catchment, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water beneath the ice stream drives lake growth. As the water body builds up, it steepens the hydraulic gradient out of the overdeepened lake basin and allows greater flux. Eventually this flux is large enough to melt channels that cause the lake to drain. Lake drainage also depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

  12. The suitability of using ASTER GDEM2 for terrain-based extraction of stream channel networks in a lowland Arctic permafrost catchment

    Anna Maria Trofaier


    Full Text Available Seasonally inundated areas and water-saturated soils are common features of lowland Arctic and sub-Arctic permafrost environments. With the onset of snow melt, and water percolation down through the snowpack, a principal factor controlling stream channel flow, aside from active layer depth, is topography. This paper investigates stream channel networks derived from the advanced spaceborne thermal emission and reflection radiometer (ASTER global digital elevation model (GDEM version 2 in a static terrain-based GIS-model. The suitability of using the ASTER GDEM2 for modelling the drainage network over a low-relief terrain is assessed. The aim is to use GDEM2 for the analysis of the stream channel network and to establish the network’s connectivity to previously observed spring flood patterns over the Yamal peninsula. As such, there are two parts to this study: 1 DEM validation and 2 stream channel network analysis. The results of the DEM validation study show that the root mean square error (RMSE of the GDEM2 and reference data is approx. 10 m when compared to both reference data sets (RMSE = 12.17 m, N = 86 and RMSE = 9.64, N = 506,877, implying that the GDEM2 is sufficiently accurate for terrain-based modelling. The low connectivity between the stream channel network and seasonal inundation suggests that topographic controls play a less important role compared to the possible overbanking of lakes and basin overflow. However, drainage densities for investigated drainage basins were significantly lower than those expected from typical Arctic basins. Both more sophisticated modelling techniques as well as higher spatial resolution DEMs are needed to extract the stream channel network more accurately and hence establish a more comprehensive link between the drainage network and seasonally inundated areas.

  13. Integrated urban drainage, status and perspectives

    Harremoës, Poul


    This paper summarises the status of urban storm drainage as an integrated professional discipline, including the management-policy interface, by which the goals of society are implemented. The paper assesses the development of the discipline since the INTERURBA conference in 1992 and includes...... with a significant conservatism in the business. However, significant integrated analyses have been reported. Most of them deal with the sewer system and the treatment plant, while few incorporate the receiving water as anything but the object of the loads to be minimised by engineering measures up-stream. Important...... measures are local infiltration, source control, storage basins, local treatment and real time control. New paradigms have been introduced: risk of pollution due to system failure, technology for water reuse, sustainability, new architecture and greener up-stream solutions as opposed to down...

  14. Vertical Analysis of Martian Drainage Basins

    Stepinski, T. F.; OHara, W. J.


    We have performed a vertical analysis of drainage basins on Mars that were computationally extracted from DEMs based on the MOLA data. Longitudinal profiles of main streams are calculated and the slope-area relation is established for 20 basins coming from assorted martian locations. An identical analysis is done for 19 terrestrial river basins. Our results show that, in comparison to terrestrial basins, martian basins have more linear longitudinal profiles, more frequent existence of knickpoints, predominance of asymmetric location of the main stream in the basin, and smaller values of concavity exponent. This suggests a limited role for surface runoff on the global scale. However, two basins extracted from the slopes of martian volcanoes show a strong similarity to terrestrial basins, indicating a possible local role for the process of surface runoff.

  15. Wound Drainage Culture (For Parents)

    ... to Be Smart About Social Media Wound Drainage Culture KidsHealth > For Parents > Wound Drainage Culture Print A A A What's in this article? ... Have Questions What It Is A wound drainage culture is a test to detect germs such as ...

  16. Human impacts to mountain streams

    Wohl, Ellen


    Mountain streams are here defined as channel networks within mountainous regions of the world. This definition encompasses tremendous diversity of physical and biological conditions, as well as history of land use. Human effects on mountain streams may result from activities undertaken within the stream channel that directly alter channel geometry, the dynamics of water and sediment movement, contaminants in the stream, or aquatic and riparian communities. Examples include channelization, construction of grade-control structures or check dams, removal of beavers, and placer mining. Human effects can also result from activities within the watershed that indirectly affect streams by altering the movement of water, sediment, and contaminants into the channel. Deforestation, cropping, grazing, land drainage, and urbanization are among the land uses that indirectly alter stream processes. An overview of the relative intensity of human impacts to mountain streams is provided by a table summarizing human effects on each of the major mountainous regions with respect to five categories: flow regulation, biotic integrity, water pollution, channel alteration, and land use. This table indicates that very few mountains have streams not at least moderately affected by land use. The least affected mountainous regions are those at very high or very low latitudes, although our scientific ignorance of conditions in low-latitude mountains in particular means that streams in these mountains might be more altered than is widely recognized. Four case studies from northern Sweden (arctic region), Colorado Front Range (semiarid temperate region), Swiss Alps (humid temperate region), and Papua New Guinea (humid tropics) are also used to explore in detail the history and effects on rivers of human activities in mountainous regions. The overview and case studies indicate that mountain streams must be managed with particular attention to upstream/downstream connections, hillslope

  17. Stream-profile analysis and stream-gradient index

    Hack, John T.


    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.

  18. Use of Pattern Classification Algorithms to Interpret Passive and Active Data Streams from a Walking-Speed Robotic Sensor Platform

    Dieckman, Eric Allen

    In order to perform useful tasks for us, robots must have the ability to notice, recognize, and respond to objects and events in their environment. This requires the acquisition and synthesis of information from a variety of sensors. Here we investigate the performance of a number of sensor modalities in an unstructured outdoor environment, including the Microsoft Kinect, thermal infrared camera, and coffee can radar. Special attention is given to acoustic echolocation measurements of approaching vehicles, where an acoustic parametric array propagates an audible signal to the oncoming target and the Kinect microphone array records the reflected backscattered signal. Although useful information about the target is hidden inside the noisy time domain measurements, the Dynamic Wavelet Fingerprint process (DWFP) is used to create a time-frequency representation of the data. A small-dimensional feature vector is created for each measurement using an intelligent feature selection process for use in statistical pattern classification routines. Using our experimentally measured data from real vehicles at 50 m, this process is able to correctly classify vehicles into one of five classes with 94% accuracy. Fully three-dimensional simulations allow us to study the nonlinear beam propagation and interaction with real-world targets to improve classification results.

  19. Predicting tile drainage discharge

    Iversen, Bo Vangsø; Kjærgaard, Charlotte; Petersen, Rasmus Jes;

    of the water load coming from the tile drainage system is therefore essential. This work aims at predicting tile drainage discharge using dynamic as well as a statistical predictive models. A large dataset of historical tile drain discharge data, daily discharge values as well as yearly average values were......More than 50 % of Danish agricultural areas are expected to be artificial tile drained. Transport of water and nutrients through the tile drain system to the aquatic environment is expected to be significant. For different mitigation strategies such as constructed wetlands an exact knowledge...... used in the analysis. For the dynamic modelling, a simple linear reservoir model was used where different outlets in the model represented tile drain as well as groundwater discharge outputs. This modelling was based on daily measured tile drain discharge values. The statistical predictive model...

  20. Acid mine drainage

    Bigham, Jerry M.; Cravotta, Charles A.


    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  1. Monitoring the impact of urbanisation on the Glinscica stream

    Brilly, Mitja; Rusjan, Simon; Vidmar, Andrej

    Stream flow regimes are determined by watershed characteristics: climate, geology, topography, soil, vegetation and human activities. In the process of urbanisation, natural land surfaces are replaced by man made artificial coverage, such as paved roads, parking lots and roofs, which usually also implies vegetation clearing and soil compaction. Gutters, drains and storm sewers are built to accelerate the conveyance of runoff to stream channels, thus affecting the drainage system. The impact of urbanisation is complex and affects different elements of the hydrological cycle. The commonly observed hydrological responses of the watershed to urbanization are increased volume and peak of floodwaters. Concerning the ecological status of stream water, the intensified rainfall runoff induces increased pollution risks and diminishes the value of the stream water body as a habitat, especially during dry periods. In order to improve the flood safety, the regulations of the stream channel have further devaluated the ecological role of the urban streams. The magnitude of the impact is usually enlarged with the decrease in the stream size. The present paper aims at presenting the results of a two-year study monitoring the impacts of the urban environment on the watershed of the Glinscica stream situated in the central part of Slovenia. The study area of 19.3 km 2 represents a great complexity in terms of the land use pattern. The watershed was equipped with three rainfall stations, a Doppler velocity meter and a water quality multiprobe. In a short period of time more than 10 thunderstorm events were recorded and analyzed. The hydrological response of the watershed was analyzed and, interestingly, it did not show the “typical” urban impact on the runoff processes. The main water quality parameters such as temperature, pH, TDS, ORP, conductivity, dissolved oxygen and especially the concentrations of nitrate and ammonium, were measured to obtain an insight into seasonal and

  2. Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability

    Simon, Troy N.; Bassar, Ronald D.; Binderup, Andrew J.; Flecker, Alex S.; Freeman, Mary C.; Gilliam, James F.; Marshall, Michael C.; Thomas, Steve A.; Travis, Joseph; Reznick, David N.; Pringle, Catherine M.


    While previous studies have shown that evolutionary divergence alters ecological processes in small-scale experiments, a major challenge is to assess whether such evolutionary effects are important in natural ecosystems at larger spatial scales. At the landscape scale, across eight streams in the Caroni drainage, we found that the presence of locally adapted populations of guppies (Poecilia reticulata) is associated with reduced algal biomass and increased invertebrate biomass, while the opposite trends were true in streams with experimentally introduced populations of non-locally adapted guppies. Exclusion experiments conducted in two separate reaches of a single stream showed that guppies with locally adapted phenotypes significantly reduced algae with no effect on invertebrates, while non-adapted guppies had no effect on algae but significantly reduced invertebrates. These divergent effects of phenotype on stream ecosystems are comparable in strength to the effects of abiotic factors (e.g., light) known to be important drivers of ecosystem condition. They also corroborate the results of previous experiments conducted in artificial streams. Our results demonstrate that local adaptation can produce phenotypes with significantly different effects in natural ecosystems at a landscape scale, within a tropical watershed, despite high variability in abiotic factors: five of the seven physical and chemical parameters measured across the eight study streams varied by more than one order of magnitude. Our findings suggest that ecosystem structure is, in part, an evolutionary product and not simply an ecological pattern.

  3. Broad-scale sampling of primary freshwater fish populations reveals the role of intrinsic traits, inter-basin connectivity, drainage area and latitude on shaping contemporary patterns of genetic diversity

    Carla Sousa-Santos


    Full Text Available Background. Worldwide predictions suggest that up to 75% of the freshwater fish species occurring in rivers with reduced discharge could be extinct by 2070 due to the combined effect of climate change and water abstraction. The Mediterranean region is considered to be a hotspot of freshwater fish diversity but also one of the regions where the effects of climate change will be more severe. Iberian cyprinids are currently highly endangered, with over 68% of the species raising some level of conservation concern. Methods. During the FISHATLAS project, the Portuguese hydrographical network was extensively covered (all the 34 river basins and 47 sub-basins in order to contribute with valuable data on the genetic diversity distribution patterns of native cyprinid species. A total of 188 populations belonging to 16 cyprinid species of Squalius, Luciobarbus, Achondrostoma, Iberochondrostoma, Anaecypris and Pseudochondrostoma were characterized, for a total of 3,678 cytochrome b gene sequences. Results. When the genetic diversity of these populations was mapped, it highlighted differences among populations from the same species and between species with identical distribution areas. Factors shaping the contemporary patterns of genetic diversity were explored and the results revealed the role of latitude, inter-basin connectivity, migratory behaviour, species maximum size, species range and other species intrinsic traits in determining the genetic diversity of sampled populations. Contrastingly, drainage area and hydrological regime (permanent vs. temporary seem to have no significant effect on genetic diversity. Species intrinsic traits, maximum size attained, inter-basin connectivity and latitude explained over 30% of the haplotype diversity variance and, generally, the levels of diversity were significantly higher for smaller sized species, from connected and southerly river basins. Discussion. Targeting multiple co-distributed species of primary

  4. Broad-scale sampling of primary freshwater fish populations reveals the role of intrinsic traits, inter-basin connectivity, drainage area and latitude on shaping contemporary patterns of genetic diversity.

    Sousa-Santos, Carla; Robalo, Joana I; Pereira, Ana M; Branco, Paulo; Santos, José Maria; Ferreira, Maria Teresa; Sousa, Mónica; Doadrio, Ignacio


    Background. Worldwide predictions suggest that up to 75% of the freshwater fish species occurring in rivers with reduced discharge could be extinct by 2070 due to the combined effect of climate change and water abstraction. The Mediterranean region is considered to be a hotspot of freshwater fish diversity but also one of the regions where the effects of climate change will be more severe. Iberian cyprinids are currently highly endangered, with over 68% of the species raising some level of conservation concern. Methods. During the FISHATLAS project, the Portuguese hydrographical network was extensively covered (all the 34 river basins and 47 sub-basins) in order to contribute with valuable data on the genetic diversity distribution patterns of native cyprinid species. A total of 188 populations belonging to 16 cyprinid species of Squalius, Luciobarbus, Achondrostoma, Iberochondrostoma, Anaecypris and Pseudochondrostoma were characterized, for a total of 3,678 cytochrome b gene sequences. Results. When the genetic diversity of these populations was mapped, it highlighted differences among populations from the same species and between species with identical distribution areas. Factors shaping the contemporary patterns of genetic diversity were explored and the results revealed the role of latitude, inter-basin connectivity, migratory behaviour, species maximum size, species range and other species intrinsic traits in determining the genetic diversity of sampled populations. Contrastingly, drainage area and hydrological regime (permanent vs. temporary) seem to have no significant effect on genetic diversity. Species intrinsic traits, maximum size attained, inter-basin connectivity and latitude explained over 30% of the haplotype diversity variance and, generally, the levels of diversity were significantly higher for smaller sized species, from connected and southerly river basins. Discussion. Targeting multiple co-distributed species of primary freshwater fish allowed

  5. Separation of drainage runoff during rainfall-runoff episodes using the stable isotope method and drainage water temperature

    Zajíček, Antonín; Kvítek, Tomáš; Pomije, Tomáš


    Stabile isotopes of 2H 18O and drainage water temperature were used as natural tracers for separation rainfall-runoff event hydrograph on several tile drained catchments located in Bohemian-Moravian Highland, Czech Republic. Small agricultural catchments with drainage systems built in slopes are typical for foothill areas in the Czech and Moravian highland. Often without permanent surface runoff, the drainage systems represent an important portion of runoff and nitrogen leaching out of the catchment. The knowledge of the drainage runoff formation and the origin of its components are prerequisites for formulation of measures leading to improvement of the drainage water quality and reduction of nutrient leaching from the drained catchments. The results have proved presence of event water in the drainage runoff during rainfall-runoff events. The proportion of event water observed in the drainage runoff varied between 15 - 60 % in the summer events and 0 - 50 % in winter events, while the sudden water temperature change was between 0,1 - 4,2 °C (2 - 35 %). The comparison of isotope separation of the drainage runoff and monitoring the drainage water temperature have demonstrated that in all cases of event water detected in the runoff, a rapid change in the drainage water temperature was observed as well. The portion of event water in the runoff grows with the growing change in water temperature. Using component mixing model, it was demonstrated that water temperature can be successfully used at least as a qualitative and with some degree of inaccuracy as a quantitative tracer as well. The drawback of the non-conservative character of this tracer is compensated by both its economic and technical accessibility. The separation results also resemble results of separations at small streams. Together with a similarly high speed of the discharge reaction to beginning of precipitation, it is obvious that the mechanism of surface runoff formation and drainage runoff formation

  6. Basin Geomorphology and Drainage Morphometry Parame-ters Used as Indicators for Groundwater Prospect:Insight from Geographical Information System (GIS) Technique

    Kumar Avinash; B Deepika; K S Jayappa


    Influence of structural and lithological controls of various drainage patterns and their stream orientations (for 2nd, 3rd and 4th order steams) were identified to evaluate the direction and controlling factors of drainage network. To investigate the prospect of groundwater, hydrogeomor-phological features of river basin viz. Mulki-Pavanje were identified and mapped. To evaluate the characteristics of the basin, different morphometric parameters (linear, areal and relief) were com-puted in sub-basin wise (SB-I to -VII). The linear parameters suggest drainage network is controlled by geomorphology. The form factor (Ff), elongation ratio (Re) and circularity ratio (Rc) suggest that the basin is in an elongated shape. The drainage density (Dd) indicates resistant/permeable strata un-der medium-dense vegetation with moderate relief. The areal parameters of the sub-basins (except SB-I and III) indicates moderate ground-slopes associated with moderately permeable rocks, which pro-mote moderate run-off and infiltration. Drainage texture (T) of the whole basin indicates coarse tex-ture while the SB-I, and III showing an intermediate texture. The relief parameters namely rugged-ness number (Rn) infers low basin relief and poor drainage density. To identify the most deficit/surplus zones of groundwater suitable weightages were assigned to the hydrogeomorphological units and morphometric parameters. The study reveal that the basin manifest that SB-III shall be most deficit zone of groundwater, whereas SB-VII, VI and V are found to show increase in groundwater potential-ity. Groundwater prospect area in this basin is estimated to be 7% area under poor, 44% area under moderate and 49% area under good to excellent. This paper demonstrated the potential application of geographical information system (GIS) techniques to evaluate the groundwater prospect in absence of traditional groundwater monitoring data.

  7. Morphometric analysis of the drainage system and its hydrological implications in the rain shadow regions, Kerala, India



    The rain shadow regions requisite a comprehensive watershed development and management plan for sustainable water resources management.The Pambar River Basin (PRB) lies on the rain shadow region of the southern Western Ghats,India,where climate showed marked intra-basin variation.A morphometric analysis was done to evaluate the drainage characteristics of PRB using topographical maps and digital elevation data.PRB was divided into eighteen 4th order basins (SB1-SB18),distributed along various climatic gradients.Lower order streams mostly dominate PRB and drainage pattern is a function of relief and structure.The terrain is highly dissected and prone to soil erosion during heavy storms and the elongated shape of PRB enables easier flood management.The influence of climate on drainage characteristics was evidently emphasized in basin morphometry.Four distinctively different classes were identified based on the morphometric similarities.The significance of morphometric analysis on the hydrological characterization is discussed and the relevance of the present study in water harvesting has been explicated.

  8. PMTree:一种高效的事件流模式匹配方法%PMTree: An Efficient Pattern Matching Method for Event Stream Processing

    程苏珺; 王永剑; 孟由; 程振东; 栾钟治; 钱德沛


    复杂事件处理技术从多个持续事件流中分析并提取满足特定模式的事件序列.高吞吐率场景下,如何快速准确地识别事件序列是复杂事件处理技术中一个非常重要的问题.现在事件流的模式匹配方法——NFA、Petri网、有向图等——存在语义描述能力不足、部分算子实现代价高等缺陷.针对这一现状,设计并实现了一种基于树的模式匹配方法——PMTree.PMTree定义了事件模型及相应事件算子,将事件序列映射为树节点,同时将时间窗口约束及谓词约束等放置在相应节点,这些树节点连接成一棵PMTree来支持实时的事件筛选与过滤.进一步研究了PMTree构建过程中的优化策略,并提出了开销模型以及优化构建算法,以尽可能减少模式匹配开销.实验结果表明,相同测试条件下基于PMTree实现的复杂事件处理引擎Cesar吞吐率是基于NFA实现的开源引擎Esper的3~6倍,并且在不同事件量或事件序列复杂度下性能表现稳定.%Complex event processing technique focuses on analyzing and extracting the event sequence of the specific pattern from the continuous event streams. Under the high-throughput situations, how to recognize the event sequence quickly and accurately has become an important problem. The state-of-the-art pattern matching methods, I. E. NFA, Petri and DAG, have shortcomings in the expressive ability and high cost to support some requirements. To deal with this situation, we propose a tree-based pattern matching method PMTree. PMTree defines event model and corresponding event relation operator, maps event pattern to the specific nodes in PMTree, applies time/predicate constraints on these nodes, and at last joins them to build a PMTree. We study the optimization strategies in the tree construction which can reduce the pattern matching cost and search the optimal combination of tree nodes, providing a cost model and an optimization algorithm. Experiments

  9. Catchment disturbance and stream metabolism: Patterns in ecosystem respiration and gross primary production along a gradient of upland soil and vegetation disturbance

    Houser, J.N.; Mulholland, P.J.; Maloney, K.O.


    Catchment characteristics determine the inputs of sediments and nutrients to streams. As a result, natural or anthropogenic disturbance of upland soil and vegetation can affect instream processes. The Fort Benning Military Installation (near Columbus, Georgia) exhibits a wide range of upland disturbance levels because of spatial variability in the intensity of military training. This gradient of disturbance was used to investigate the effect of upland soil and vegetation disturbance on rates of stream metabolism (ecosystem respiration rate [ER] and gross primary production rate [GPP]). Stream metabolism was measured using an open-system, single-station approach. All streams were net heterotrophic during all seasons. ER was highest in winter and spring and lowest in summer and autumn. ER was negatively correlated with catchment disturbance level in winter, spring, and summer, but not in autumn. ER was positively correlated with abundance of coarse woody debris, but not significantly related to % benthic organic matter. GPP was low in all streams and generally not significantly correlated with disturbance level. Our results suggest that the generally intact riparian zones of these streams were not sufficient to protect them from the effect of upland disturbance, and they emphasize the role of the entire catchment in determining stream structure and function. ?? 2005 by The North American Benthological Society.

  10. Non-indigenous bamboo along headwater streams of the Luquillo Mountains, Puerto Rico: Leaf fall, aquatic leaf decay and patterns of invasion

    O'Connor, P. J.; Covich, A.P.; Scatena, F.N.; Loope, L.L.


    The introduction of bamboo to montane rain forests of the Luquillo Mountains, Puerto Rico in the 1930s and 1940s has led to present-day bamboo monocultures in numerous riparian areas. When a non-native species invades a riparian ecosystem, in-stream detritivores can be affected. Bamboo dynamics expected to influence stream communities in the Luquillo Experimental Forest (LEF) were examined. Based on current distributions, bamboo has spread down-stream at a rate of 8 m y-1. Mean growth rate of bamboo culms was 15.3 cm d-1. Leaf fall from bamboo stands exceeded that of native mixed-species forest by c. 30% over a 10-mo study. Bamboo leaves (k = -0.021), and leaves from another abundant riparian exotic, Syzygium jambos (Myrtaceae) (k = -0.018), decayed at relatively slow rates when submerged in streams in fine-mesh bags which excluded macro-invertebrate leaf processors. In a second study, with leaf processors present, bamboo decay rates remained unchanged (k = -0.021), while decay rates of S. jambos increased (k = -0.037). Elemental losses from bamboo leaves in streams were rapid, further suggesting a change in riparian zone/stream dynamics following bamboo invasion. As non-indigenous bamboos spread along Puerto Rico streams, they are likely to alter aquatic communities dependent on leaf input.

  11. Shifts in the trophic base of intermittent stream food webs

    Dekar, Matthew P.; Magoulick, Daniel D.; Huxel, G.R.


    Understanding spatial and temporal variation in the trophic base of stream food webs is critical for predicting population and community stability, and ecosystem function. We used stable isotope ratios (13C/12C, and 15N/14N) to characterize the trophic base of two streams in the Ozark Mountains of northwest Arkansas, U.S.A. We predicted that autochthonous resources would be more important during the spring and summer and allochthonous resources would be more important in the winter due to increased detritus inputs from the riparian zone during autumn leaf drop. We predicted that stream communities would demonstrate increased reliance on autochthonous resources at sites with larger watersheds and greater canopy openness. The study was conducted at three low-order sites in the Mulberry River Drainage (watershed area range: 81-232 km2) seasonally in 2006 and 2007. We used circular statistics to examine community-wide shifts in isotope space among fish and invertebrate consumers in relation to basal resources, including detritus and periphyton. Mixing models were used to quantify the relative contribution of autochthonous and allochthonous energy sources to individual invertebrate consumers. Significant isotopic shifts occurred but results varied by season and site indicating substantial variation in the trophic base of stream food webs. In terms of temporal variation, consumers shifted toward periphyton in the summer during periods of low discharge, but results varied during the interval between summer and winter. Our results did not demonstrate increased reliance on periphyton with increasing watershed area or canopy openness, and detritus was important at all the sites. In our study, riffle-pool geomorphology likely disrupted the expected spatial pattern and stream drying likely impacted the availability and distribution of basal resources.

  12. Dietary change and fate of related waste streams

    Korpalska, Magdalena


    Food consumption patterns or dietary patterns are repeated arrangements observed in food consumption by a population group. Organic waste streams are by-products of the food production which are not suitable for human consumption. Nowadays, waste streams

  13. Dietary change and fate of related waste streams

    Korpalska, Magdalena


    Food consumption patterns or dietary patterns are repeated arrangements observed in food consumption by a population group. Organic waste streams are by-products of the food production which are not suitable for human consumption. Nowadays, waste streams

  14. Drainage Areas of Streams at Selected Locations in Kentucky


    near Somerset --Lat 37 ° 08 107", Long 84 ° 35 118", at bridge on State Highway 39 199 BOBTOWN 23 .8 38 .3 26 .3 68 .1 03412500 Pitman Creek near... Somerset --Lat 37 ° 07 1 01", Long 84 ° 35 1 31", 0 .1 mile downstream from Dry Branch 199 SOMERSET 22 .3 35 .9 31 .3 81 .1 Pitman Creek at mouth--Lat...34, Long 85 0 32󈧉" 171 VERNON 397.9 640 .2 6,215 16,097 (Area in Kentucky) 4,904 12,701 (Area outside Kentucky) 1,311 3,395 Meshack Creek at mouth--Lot

  15. Stream Evaluation

    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. Geospatial datasets for watershed delineation and characterization used in the Hawaii StreamStats web application

    Rea, Alan; Skinner, Kenneth D.


    The U.S. Geological Survey Hawaii StreamStats application uses an integrated suite of raster and vector geospatial datasets to delineate and characterize watersheds. The geospatial datasets used to delineate and characterize watersheds on the StreamStats website, and the methods used to develop the datasets are described in this report. The datasets for Hawaii were derived primarily from 10 meter resolution National Elevation Dataset (NED) elevation models, and the National Hydrography Dataset (NHD), using a set of procedures designed to enforce the drainage pattern from the NHD into the NED, resulting in an integrated suite of elevation-derived datasets. Additional sources of data used for computing basin characteristics include precipitation, land cover, soil permeability, and elevation-derivative datasets. The report also includes links for metadata and downloads of the geospatial datasets.

  17. Stream Lab

    Kummel, Miro; Bruder, Andrea; Powell, Jim; Kohler, Brynja; Lewis, Matt


    Dead leaves, ping-pong balls or plastic golf balls are floated down a small stream. The number of leaves/balls passing recording stations along the stream are tallied. Students are then challenged to develop a transport model for the resulting data. From this exercise students gain greater understanding of PDE modeling, conservation laws, parameter estimation as well as mass and momentum transport processes.

  18. Sustainable Drainage Systems

    Miklas Scholz


    Full Text Available Urban water management has somewhat changed since the publication of The Sustainable Drainage System (SuDS Manual in 2007 [1], transforming from building traditional sewers to implementing SuDS, which are part of the best management practice techniques used in the USA and seen as contributing to water-sensitive urban design in Australia. Most SuDS, such as infiltration trenches, swales, green roofs, ponds, and wetlands, address water quality and quantity challenges, and enhance the local biodiversity while also being acceptable aesthetically to the public. Barriers to the implementation of SuDS include adoption problems, flood and diffuse pollution control challenges, negative public perception, and a lack of decision support tools addressing, particularly, the retrofitting of these systems while enhancing ecosystem services. [...

  19. Right Gastric Venous Drainage: Angiographic Analysis in 100 Patients

    Seong, Nak Jong [Seoul National University Bundang Hospital, Sungnam (Korea, Republic of); Chung, Jin Wook; Kim, Hyo Cheol; Park, Jae Hyung; Jae, Hwan Jun [Seoul National University Hospital, Seoul (Korea, Republic of); An, Sang Bu [National Cancer Center, Ilsan (Korea, Republic of); Cho, Baik Hwan [Chonbuk National University Hospital, Chonju (Korea, Republic of)


    To evaluate the pattern of right gastric venous drainage by use of digital subtraction angiography. A series of 100 consecutive patients who underwent right gastric arteriography during transcatheter arterial chemoembolization for hepatocellular carcinoma were included in this study. Angiographic findings were retrospectively analyzed with respect to the presence or absence of the right and aberrant gastric veins, multiplicity of draining veins, aberrant right gastric venous drainage sites, and the termination pattern of aberrant right gastric veins (ARGVs). We also compared the relative size of the right and left gastric veins. A total of 49 patients collectively had 66 ARGVs. The common drainage sites for the ARGVs included the hepatic segment IV (n = 35) and segment I (n = 15). The termination pattern of ARGV could be classified into 4 different types. The most common type was termination as a superficial parenchymal blush formation in small areas without demonstrable portal branches. A statistically significant difference was found for the dominance of the right gastric vein in gastric venous drainage between the two groups with or without ARGV (p < 0.05, Fisher's exact test). In the group of patients without ARGV (n = 51), the right gastric vein was equal to (n = 9) or larger than (n = 17) the left gastric vein in 26 patients (26 of 51, 51%). The incidence of ARGV is higher than expected with four distinct types in its termination pattern. The right gastric vein may play a dominant role in gastric venous drainage.

  20. An investigation into the use of road drainage structures by wildlife in Maryland, USA

    Sparks, James L; Gates, J. Edward


    Culverts have been installed beneath roadways for drainage or to contain existing streams; however, most of them have not been installed to facilitate the passage of wildlife. Prior studies of existing drainage structures used by wildlife have been narrow in scope, targeting a restricted number of culverts, time periods, or locales. Use of culverts by wildlife has been postulated to promote connectivity of fragmented populations and their habitats and to reduce roadkills. We monitored 265 cul...

  1. OCPM:一种数据流上复合模式的在线匹配方法%OCPM:An Online Composite Pattern Matching Method over Data Streams

    巨程; 李红燕; 李菲菲; 曲强


    Sequential data segments in data streams are highly valuable in many areas, they support abundant semantics and have complicated forms. Matching these segments need real - time processing. This paper presents an online composite pattern matching method over data streams (OCPM). To support complex forms of target pattern, OCPM identify invariant segment as basic pattern. Pattern matching operators are defined over basic patterns. Based on basic patterns, target pattern is generated after the operation. To accomplish the pattern matching efficiently, pattern matching operator tree (PMOTree) is created based on target pattern. Data segments are then recognized as basic patterns and flow into leaf nodes. Later matching procedures are operated according to the types of nodes in PMOTree. From the perspective of recall ratio, precision ratio and processing efficiency, the experimental results on real datasets of medical streams show that OCPM is feasible and effective.%连续数据波段在数据流中具有很高的领域价值,它们能表达丰富的含义,因此形式非常复杂,其匹配识别过程也具有实时性的要求.针对这些特点及要求,这里提出了一种数据流上的复合模式在线匹配方法(OCPM).为了支持匹配目标的复杂形式,该方法用基模式刻画连续波段中的相对不变的基本波段,在基模式上定义操作符集,基模式通过操作符的复合运算生成目标模式.为了高效完成目标匹配,算法针对目标模式构建操作符树(PMOTree).操作符树的叶节点把数据流波段识别为基模式,然后根据树中不同类型节点对应的处理算法,自底向上完成目标模式的匹配.实验采用真实场景中的医疗数据流,通过对查全率、查准率和匹配效率的实验结果分析,证明了OCPM方法具有可行性与实用性.

  2. Integrated urban drainage, status and perspectives

    Harremoës, Poul


    with a significant conservatism in the business. However, significant integrated analyses have been reported. Most of them deal with the sewer system and the treatment plant, while few incorporate the receiving water as anything but the object of the loads to be minimised by engineering measures up-stream. Important...... aspects of the papers presented at the INTERURBA-II conference in 2001 and the discussions during the conference. Tools for integrated analysis have been developed, but there is less implementation than could be expected. That is due to lack of adequate knowledge about important mechanisms, coupled......This paper summarises the status of urban storm drainage as an integrated professional discipline, including the management-policy interface, by which the goals of society are implemented. The paper assesses the development of the discipline since the INTERURBA conference in 1992 and includes...

  3. Patterns of fish community structure in a long-term watershed-scale study to address the aquatic ecosystem effects of pulp and paper mill discharges in four US receiving streams.

    Flinders, Camille A; Ragsdale, Renee L; Hall, Timothy J


    Physiological changes have been seen in individual fish exposed to pulp and paper mill effluent (PPME), but it is unclear whether community-level changes are seen in fish in PPME receiving waters. We conducted a study of 4 PPME receiving streams (Codorus Creek, PA, USA), the Leaf River (Forrest and Perry Counties, MS, USA), and the McKenzie and Willamette rivers (Lane County, OR, USA) over 9 y to assess temporal patterns in the type and relative abundance of fish species and measures of community structure and function related to PPME discharge. We used boat and backpack electrofishing to sample large- and small-bodied fish from the McKenzie and Willamette rivers, boat electrofishing to sample large-bodied fish from the Leaf River, and backpack electrofishing to sample the entire fish community from Codorus Creek. Study streams represented different ecoregions, warm- and coldwater systems, gradients of PPME concentration (mill process types. Bray-Curtis similarity and nonmetric multidimensional scaling showed high variation in fish communities across sites, seasons, and years. Significant site differences in fish communities were seen in most streams and community types, but distinct separation of sites was seen only in Codorus Creek and unrelated to PPME discharge. No seasonal differences were seen in fish community structure in any stream, with only weak annual patterns in large-bodied fish in the Leaf River and small-bodied fish in the McKenzie River. General linear models were used to examine spatial and temporal variation in fish metric response (abundance, species richness, Simpson's diversity, % dominant species, standing crop, % DELT, % intolerant, % omnivore, % piscivore). Significant site differences in metric response were largely limited to Codorus Creek and unrelated to PPME. Significant reductions of % dominant taxa of small-bodied fish and % large-bodied piscivores were also observed downstream of the PPME discharge on the McKenzie River relative to

  4. Development of Ecogeomorphological (EGM Stream Design and Assessment Tools for the Piedmont of Alabama, USA

    Brian Helms


    Full Text Available Regional data needed for effective stream restoration include hydraulic geometry relationships (i.e., regional curves and reference channel morphology parameters. Increasingly ecological conditions are being considered when designing, implementing, and assessing restoration efforts. We provide morphology relationships and associated ecological endpoint curves for reference streams in the Alabama piedmont. Twenty-one reference stream reaches were identified in the Tallapoosa drainage of Alabama, ranging from 0.2 to 242 km2 drainage area. Geomorphic surveys were conducted in each stream to measure riffle cross-sections and longitudinal profiles and related to drainage area to develop regional curves. Fish, crayfish, and benthic macroinvertebrates were collected from each surveyed reach and related to drainage area and geomorphic data to provide associated biological community endpoints. Bankfull channel cross-section area, width, mean depth, and estimated discharge were strongly correlated to watershed drainage area, similar to efforts in other areas of the Piedmont ecoregion. Multiple measures of fish assemblages and crayfish size were strongly predicted by drainage area and geomorphic dimensions. Macroinvertebrates showed no taxonomic and limited functional relationships with drainage area and geomorphic dimension. These tools, which integrate geomorphological and ecological conditions, can result in improved stream evaluations and designs increasing the effectiveness of stream restoration projects.

  5. Strike slip faulting inferred from offsetting of drainages: Lower Narmada basin, western India

    Rachna Raj


    The detailed analysis of landforms,drainages and geology of the area between the rivers Amaravati and Karjan was carried out in order to understand the tectonic history of the lower Narmada basin. Movement along the various faults in the area was studied on the basis of the drainage offsetting. Horizontal offsetting of stream channels was found quite demonstrable along NNW –SSE trending transverse faults.Tectonic landforms including systematic de flection of stream channels and ridges, alignment of fault scarp and saddles and displacement in the basement rocks and alluvial deposits show that the area is undergoing active deformation driven by the NSF system.

  6. Drainage Analysis of the South American Landscape and its Tectonic Implications

    Rodríguez Tribaldos, Verónica; White, Nicholas J.; Roberts, Gareth G.


    The majority of studies aimed at investigating topographic growth and landscape evolution have limited spatial coverage. Frequently, spot measurements of uplift and denudation are only available, which hampers spatial resolution of the growth of regional topographic features. This limitation can be overcome by quantitatively analysing substantial, continent-wide, drainage networks. The shapes of long wavelength longitudinal river profiles appear to be mainly controlled by regional uplift and moderated by erosional processes, both of which can vary as a function of space and time. By parametrizing erosional histories, it is feasible to develop inverse models that permit spatial and temporal patterns of regional uplift to be reliably retrieved. Here, a drainage inventory for South America consisting of 1827 rivers has been inverted. River profiles were extracted from the SRTM topographic dataset and modelled using a simplified version of the stream-power law, in which erosional processes are described using a linear advective formulation. The inverse problem is then solved by seeking smooth uplift rate histories that minimize the misfit between observed and calculated river profiles using a linearized, damped, non-negative, least squares algorithm. Calibration of erosional processes is achieved by inverting the complete drainage inventory and seeking a calculated uplift history that best honours independent geological observations from the Borborema Province of northeast Brazil. This province experienced regional Cenozoic uplift. Calculated uplift rate histories for South America suggest that the bulk of its topography developed during Cenozoic times. The model suggests, for instance, that the Andean mountain chain mostly arose in late Eocene-Oligocene (i.e. 40-28 Ma) times with an increase in elevation during Miocene times (i.e. the last 20 Ma). Uplift of the Central Andean Altiplano from an elevation of ~ 1 km to its present-day height of ~ 4 km occurred within the

  7. stream-stream: Stellar and dark-matter streams interactions

    Bovy, Jo


    Stream-stream analyzes the interaction between a stellar stream and a disrupting dark-matter halo. It requires galpy (ascl:1411.008), NEMO (ascl:1010.051), and the usual common scientific Python packages.

  8. Hand Recognition in Live-Streaming Video

    Mikhail, Belov


    The article describes the algorithmic component of the pattern recognition method for extracting hand patterns from a video stream. Methods removing excess information from frames, localizing fragments with a hand and extracting hand contours to classify them are described.

  9. Reactive solute transport in an acidic stream: Experimental pH increase and simulation of controls on pH, aluminum, and iron

    Broshears, R.E.; Runkel, R.L.; Kimball, B.A.; McKnight, Diane M.; Bencala, K.E.


    Solute transport simulations quantitatively constrained hydrologic and geochemical hypotheses about field observations of a pH modification in an acid mine drainage stream. Carbonate chemistry, the formation of solid phases, and buffering interactions with the stream bed were important factors in explaining the behavior of pH, aluminum, and iron. The precipitation of microcrystalline gibbsite accounted for the behavior of aluminum; precipitation of Fe(OH)3 explained the general pattern of iron solubility. The dynamic experiment revealed limitations on assumptions that reactions were controlled only by equilibrium chemistry. Temporal variation in relative rates of photoreduction and oxidation influenced iron behavior. Kinetic limitations on ferrous iron oxidation and hydrous oxide precipitation and the effects of these limitations on field filtration were evident. Kinetic restraints also characterized interaction between the water column and the stream bed, including sorption and desorption of protons from iron oxides at the sediment-water interface and post-injection dissolution of the precipitated aluminum solid phase.

  10. Salamander occupancy in headwater stream networks

    Grant, E.H.C.; Green, L.E.; Lowe, W.H.


    1. Stream ecosystems exhibit a highly consistent dendritic geometry in which linear habitat units intersect to create a hierarchical network of connected branches. 2. Ecological and life history traits of species living in streams, such as the potential for overland movement, may interact with this architecture to shape patterns of occupancy and response to disturbance. Specifically, large-scale habitat alteration that fragments stream networks and reduces connectivity may reduce the probability a stream is occupied by sensitive species, such as stream salamanders. 3. We collected habitat occupancy data on four species of stream salamanders in first-order (i.e. headwater) streams in undeveloped and urbanised regions of the eastern U.S.A. We then used an information-theoretic approach to test alternative models of salamander occupancy based on a priori predictions of the effects of network configuration, region and salamander life history. 4. Across all four species, we found that streams connected to other first-order streams had higher occupancy than those flowing directly into larger streams and rivers. For three of the four species, occupancy was lower in the urbanised region than in the undeveloped region. 5. These results demonstrate that the spatial configuration of stream networks within protected areas affects the occurrences of stream salamander species. We strongly encourage preservation of network connections between first-order streams in conservation planning and management decisions that may affect stream species.

  11. Long-term Patterns of Microhabitat Use by Fish in a Southern Appalachian Stream from 1983 to 1992: Effects of Hydrologic Period, Season and Fish Length

    Gary D. Grossman; Robert E. Ratajczak


    We quantified microhabitat use by members of a southern Appalachian stream fish assemblage over a ten-year period that included both floods and droughts. Our study site (37 m in length) encompassed riffle, run and pool habitats. Previous research indicated that species belonged to either benthic or water-column microhabitat guilds. Most species exhibited non-random...

  12. Filter Fabrics for Airport Drainage.


    Systems for *r- field Pavements," Harry R. Cedergren . d. "Development of Guidelines for the Design of Subsurfac( Drainage Systems for Highway Pavement...Structural 4Sectic s," H. R. Cedergren , J. A. Arman, and K. H. O’Brien. e. Drainage of Highway and Airfield Pavements, Harry R. Cedergren .> Cedergren (974).5 Additionally, several references were used, particularly those describing experimental anu construction prolects using filter

  13. Hyporheic Exchange Flows and Biogeochemical Patterns near a Meandering Stream: East Fork of the Jemez River, Valles Caldera National Preserve, New Mexico

    Christensen, H.; Wooten, J. P.; Swanson, E.; Senison, J. J.; Myers, K. D.; Befus, K. M.; Warden, J.; Zamora, P. B.; Gomez, J. D.; Wilson, J. L.; Groffman, A.; Rearick, M. S.; Cardenas, M. B.


    A study by the 2012 Hydrogeology Field Methods class of the University of Texas at Austin implemented multiple approaches to evaluate and characterize local hyporheic zone flow and biogeochemical trends in a highly meandering reach of the of the East Fork of the Jemez River, a fourth order stream in northwestern New Mexico. This section of the Jemez River is strongly meandering and exhibits distinct riffle-pool morphology. The high stream sinuosity creates inter-meander hyporheic flow that is also largely influenced by local groundwater gradients. In this study, dozens of piezometers were used to map the water table and flow vectors were then calculated. Surface water and ground water samples were collected and preserved for later geochemical analysis by ICPMS and HPLC, and unstable parameters and alkalinity were measured on-site. Additionally, information was collected from thermal monitoring of the streambed, stream gauging, and from a series of electrical resistivity surveys forming a network across the site. Hyporheic flow paths are suggested by alternating gaining and losing sections of the stream as determined by stream gauging at multiple locations along the reach. Water table maps and calculated fluxes across the sediment-water interface also indicate hyporheic flow paths. We find variability in the distribution of biogeochemical constituents (oxidation-reduction potential, nitrate, ammonium, and phosphate) along interpreted flow paths which is partly consistent with hyporheic exchange. The variability and heterogeneity of reducing and oxidizing conditions is interpreted to be a result of groundwater-surface water interaction. Two-dimensional mapping of biogeochemical parameters show redox transitions along interpreted flow paths. Further analysis of various measured unstable chemical parameters results in observable trends strongly delineated along these preferential flow paths that are consistent with the direction of groundwater flow and the assumed

  14. Acid Rain Effects on Adirondack Streams - Results from the 2003-05 Western Adirondack Stream Survey (the WASS Project)

    Lawrence, Gregory B.; Roy, Karen M.; Baldigo, Barry P.; Simonin, Howard A.; Passy, Sophia I.; Bode, Robert W.; Capone, Susan B.


    Traditionally lakes have been the focus of acid rain assessments in the Adirondack region of New York. However, there is a growing recognition of the importance of streams as environmental indicators. Streams, like lakes, also provide important aquatic habitat, but streams more closely reflect acid rain effects on soils and forests and are more prone to acidification than lakes. Therefore, a large-scale assessment of streams was undertaken in the drainage basins of the Oswegatchie and Black Rivers; an area of 4,585 km2 in the western Adirondack region where acid rain levels tend to be highest in New York State.

  15. Quantifying the effects of stream channels on storm water quality in a semi-arid urban environment

    Gallo, Erika L.; Lohse, Kathleen A.; Brooks, Paul D.; McIntosh, Jennifer C.; Meixner, Thomas; McLain, Jean E. T.


    SummaryStormwater drainage systems can have a large effect on urban runoff quality, but it is unclear how ephemeral urban streams alter runoff hydrochemistry. This problem is particularly relevant in semi-arid regions, where urban storm runoff is considered a renewable water resource. Here we address the question: how do stream channels alter urban runoff hydrochemistry? We collected synoptic stormwater samples during three rainfall-runoff events from nine ephemeral streams reaches (three concrete or metal, three grass, three gravel) in Tucson, Arizona. We identified patterns of temporal and spatial (longitudinal) variability in concentrations of conservative (chloride and isotopes of water) and reactive solutes (inorganic-N, soluble reactive phosphorous, sulfate-S, dissolved organic carbon (DOC) and nitrogen, and fecal indicator bacteria). Water isotopes and chloride (Cl) concentrations indicate that solute flushing and evapoconcentration alter temporal patterns in runoff hydrochemistry, but not spatial hydrochemical responses. Solute concentrations and stream channel solute sourcing and retention during runoff were significantly more variable at the grass reaches (CV = 2.3 - 144%) than at the concrete or metal (CV = 1.6 - 107%) or gravel reaches (CV = 1.9 - 60%), which functioned like flow-through systems. Stream channel soil Cl and DOC decreased following a runoff event (Cl: 12.1-7.3 μg g-1 soil; DOC: 87.7-30.1 μg g-1 soil), while soil fecal indicator bacteria counts increased (55-215 CFU g-1 soil). Finding from this study suggest that the characteristics of the ephemeral stream channel substrate control biogeochemical reactions between runoff events, which alter stream channel soil solute stores and the hydrochemistry of subsequent runoff events.

  16. Long-term patterns of chironomid assemblages in a high elevation stream/lake network (Switzerland – Implications to global change

    Brigitte Lods-Crozet


    Full Text Available A long-term monitoring program was initiated in 2002 on running and standing waters in a high elevation cirque landscape (Macun in the Swiss National Park. The region comprises contrasting basins with different water sources, a glacier-fed basin and two precipitation-fed basins. Sampling of 26 permanent and temporary ponds (or small lakes and of interconnecting streams (10 sites was conducted from 2002 to 2010. Pond macroinvertebrate assemblages were dominated by chironomids with 42 taxa. The Orthocladiinae were the dominant subfamily in richness and abundance with 22 taxa. The greatest diversity was found in ponds located in the south and outlet basins. The inter-year variability for the same pond is high, but no clear temporal trend was noticed in ponds frequently monitored ponds. The Orthocladiinae subfamily was also the richest in the stream sites where 33 taxa were collected. The north and south basins were separated on the basis of chironomid assemblages. The chironomid assemblages in the stream network shows a temporal trend from 2002 but it cannot be linked to any clear change at the community structure level. The higher richness and abundance in stream sites and ponds of the south basin could be related to a greater heterogeneity in water physico-chemistry and substrata, and by the presence of Bryophyta. The understanding of the environmental factors that influence faunal assemblages is crucial for the protection of this sensitive alpine pond network where a relatively high overall regional diversity (49 taxa is detected. From the literature, temperature is recognized as the driving force on changes in chironomid assemblages in alpine systems. Our results support the use of chironomids as flagship indicators in the assessment of climatic change in alpine landscapes.doi: 10.5324/fn.v31i0.1361.Published online: 17 October 2012.

  17. Migratory patterns of hatchery and stream-reared Atlantic salmon Salmo salar smolts in the Connecticut River, U.S.A.

    McCormick, Stephen D.; Haro, Alexander; Lerner, Darren T.; O'Dea, Michael F.; Regish, Amy M.


    The timing of downstream migration and detection rates of hatchery-reared Atlantic salmon Salmo salar smolts and stream-reared smolts (stocked 2 years earlier as fry) were examined in the Connecticut River (U.S.A.) using passive integrated transponder (PIT) tags implanted into fish and then detected at a downstream fish bypass collection facility at Turners Falls, MA (river length 192 km). In two successive years, hatchery-reared smolts were released in mid-April and early May at two sites: the West River (river length 241 km) or the Passumpsic (river length 450 km). Hatchery-reared smolts released higher in the catchment arrived 7 to 14 days later and had significantly lower detection rates than smolts stocked lower in the catchment. Hatchery-reared smolts released 3 weeks apart at the same location were detected downstream at similar times, indicating that early-release smolts had a lower average speed after release and longer residence time. The size and gill Na+/K+-ATPase (NKA) activity of smolts at the time of release were significantly greater for detected fish (those that survived and migrated) than for those that were not detected. Stream-reared pre-smolts (>11·5 cm) from four tributaries (length 261–551 km) were tagged in autumn and detected during smolt migration the following spring. Stream-reared smolts higher in the catchment arrived later and had significantly lower detection rates. The results indicate that both hatchery and stream-reared smolts from the upper catchment will arrive at the mouth of the river later and experience higher overall mortality than fish from lower reaches, and that both size and gill NKA activity are related to survival during downstream migration.

  18. Morphology and channel evolution of small streams in the southern Blue Ridge mountains of western North Carolina

    David Leigh


    Small streams are understudied in the Southern Blue Ridge Mountains, yet they constitute a huge portion of the drainage network and are relevant with respect to human impact on the landscape and stream restoration efforts. Morphologies of 44 streams (0.01 to 20 km2 watersheds) from western North Carolina are characterized and couched in the context of historical...

  19. Assessment of zinc loading in an acid rock drainage alpine catchment using a tracer-injection and synoptic-sampling study

    Crouch, C. M.; McKnight, D. M.; Todd, A.


    Seasonal low flow conditions in acid rock drainage (ARD) streams result in increased acidity and metal ion concentrations - changes that have been shown to become more pronounced with longer dry periods. These resulting increases in acidity and metals concentrations may pose an increasing danger to aquatic ecosystems and drinking water supplies. For example, in many ARD-impacted mountain streams, fish populations are not self-sustaining. The study site in the Upper Snake River watershed in Colorado is an alpine catchment impacted by acid rock drainage thought to originate from the natural weathering of pyrite whereas the main stem of the Snake River and its other tributaries are impacted by accelerated ARD resulting from historic mining activities. Because concentrations toxic to aquatic life persist well downstream of the ARD inputs, dissolved zinc is the primary metal of concern in this study. A compilation of historic data from the Snake River Watershed during the low flow months of September and October indicates that zinc concentrations have increased four-fold over the past 30 years. We hypothesize that this increase is due to changes in groundwater flow patterns caused by climate change and associated earlier peak snowmelt (by 2-3 weeks), resulting in lower stream flows and drier soils in late summer. The observed increase in background metals concentrations has implications for mitigation of former mining sites. A synoptic study to identify discrete surface water sources of zinc loading indicated a significant input from a tributary on the north side of the catchment. Zinc concentrations here measured an order of magnitude higher than in the main stem of the stream, and were correlated with increases in sulfate, hardness, and total metals, supporting our contention that increasing zinc concentrations are driven by the acceleration of ARD in the watershed. The current research further investigates sources of metal-rich inflows to the tributary using a tracer

  20. Tectonic and lithological controls on fluvial landscape development in central-eastern Portugal: Insights from long profile tributary stream analyses

    Martins, António A.; Cabral, João; Cunha, Pedro P.; Stokes, Martin; Borges, José; Caldeira, Bento; Martins, A. Cardoso


    This study examines the long profiles of tributaries of the Tagus and Zêzere rivers in Portugal (West Iberia) in order to provide new insights into patterns, timing, and controls on drainage development during the Quaternary incision stage. The studied streams are incised into a relict culminant fluvial surface, abandoned at the beginning of the incision stage. The streams flow through a landscape with bedrock variations in lithology (mainly granites and metasediments) and faulted blocks with distinct uplift rates. The long profiles of the analyzed streams record an older transitory knickpoint/knickzone separating (1) an upstream relict graded profile, with lower steepness and higher concavity, that reflects a long period of quasi-equilibrium conditions reached after the beginning of the incision stage, and (2) a downstream rejuvenated long profile, with steeper gradient and lower concavity, particularly for the final reach, which is often convex. The rejuvenated reaches testify to the upstream propagation of several incision waves, interpreted as the response of each stream to increasing crustal uplift and prolonged periods of base-level lowering by the trunk drainages, coeval with low sea level conditions. The morphological configurations of the long profiles enabled spatial and relative temporal patterns of incisions to be quantified. The incision values of streams flowing on the Portuguese Central Range (PCR; ca. 380-150 m) are variable but generally higher than the incision values of streams flowing on the adjacent South Portugal Planation Surface (SPPS; ca. 220-110 m), corroborating differential uplift of the PCR relative to the SPPS. Owing to the fact that the relict graded profiles can be correlated with the Tagus River T1 terrace (1.1-0.9 My) present in the study area, incision rates can be estimated (1) for the streams located in the PCR, 0.38-0.15 m/ky and (2) for the streams flowing on the SPPS, 0.22-0.12 m/ky. The differential uplift inferred in the

  1. Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads

    Schilling, K. E.; Arenas Amado, A.; Jones, C. S.; Weber, L. J.


    Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.




    Full Text Available Providing adequate drainage to a pavement system has been considered as an important design consideration to prevent premature failures due to water related problems such as pumping action, loss of support, and rutting, among others. Most water in pavements is due to rainfall infiltration into unsaturated pavement layers, throughjoints, cracks, shoulder edges, and various other defects, especially in older deteriorated pavements. Water also seep upward from a high groundwater table due to capillary suction or vapour movements, or it may flow laterally from the pavement edges and side ditches. Providing adequate drainage to a pavement system has been considered as an important design consideration to ensure satisfactory performance of the pavement, particularly from the perspective of life cycle cost and serviceability. To minimize premature pavement distresses and to enhance the pavement performance, it is imperative to provide adequate drainage to allow infiltrated water to drain out from the base and sub-base, thus avoiding saturation of base and subgrade soils. This paper deals with the analysis of the impact of subsurface drainage on pavement system performance. The requirement ofeffective subsurface drainage for pavement performance is also discussed.

  3. Effect Of Imposed Anaerobic Conditions On Metals Release From Acid-Mine Drainage Contaminated Streambed Sediments

    Remediation of streams influenced by mine-drainage may require removal and burial of metal-containing bed sediments. Burial of aerobic sediments into an anaerobic environment may release metals, such as through reductive dissolution of metal oxyhydroxides. Mining-impacted aerob...

  4. Influence of Physical Habitat and Agricultural Contaminants on Fishes within Agricultural Drainage Ditches

    Agricultural drainage ditches are used within agricultural watersheds for the removal of excess water from agricultural fields. These headwater streams have been constructed or modified so they possess an enlarged trapezoidal cross-section, straightened channels, and riparian zones lacking woody veg...

  5. Distribution and biophysical processes of beaded streams in Arctic permafrost landscapes

    Arp, Christopher D.; Whitman, Matthew S.; Jones, Benjamin M.; Grosse, Guido; Gaglioti, Benjamin V.; Heim, Kurt C.


    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 survey 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- ground 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 a relatively stable landform 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 riparian zones effectively insulates channel 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 thermally stratify, 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, yet channel runs still move water rapidly

  6. StreamMap: Smooth Dynamic Visualization of High-Density Streaming Points.

    Li, Chenhui; Baciu, George; Yu, Han


    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.

  7. Hydraulic Characteristics of the San Gregorio Creek Drainage Basin, California: a Preliminary Study.

    Davis, J. R.; Snow, M. K.; Pestrong, R.; Sklar, L. S.; Vavro, M.; Sawachi, A.; Talapian, E.; Bailey, E.


    Population pressures within the greater San Francisco Bay Area are forcing development into nearby rural communities, and are impacting local environments. This study of the San Gregorio Creek Watershed is designed as a baseline for evaluating the effect increasing development within the drainage basin has on its river system. We hope to provide evidence for that impact through laboratory and field studies that provide a snap-shot of this drainage basin's current characteristics. The San Gregorio Creek watershed, in the Coast Ranges, is located in the southwestern portion of San Mateo County, California. It drains the western slopes of the Santa Cruz Mountains, in the Coast Ranges into the Pacific Ocean at the town of San Gregorio. Most of its fingertip tributaries flow into the trunk from the north and west, with elevations as high as 2050 feet. The watershed includes an area of approximately 51.6 square miles and San Gregorio Creek, the trunk stream, is roughly 12 miles long. San Gregorio Creek is a fourth order perennial stream. It is fed by a number of major tributaries, the largest of which are Alpine, Mindego, and La Honda creeks. The U.S. Geological Survey maintains a stream gauging station for San Gregorio Creek at the town of San Gregorio, where it has been monitoring stream flows for more than 30 years through its Water Resources Department. The resulting data indicate a mean discharge of 36.4 cfs. Map studies of hydraulic geometry for the drainage basin reveal geometric characteristics for San Gregorio Creek that coincide with similar streams in comparable climatic and environmental settings. Stream table studies are used to further investigate fundamental stream processes. Field studies at selected reaches throughout the drainage basin will document hydraulic characteristics. The results of this study will contribute to more comprehensive studies demonstrateing channel response to changing environmental conditions.

  8. Denitrification in agriculturally impacted streams: seasonal changes in structure and function of the bacterial community.

    Erin Manis

    Full Text Available Denitrifiers remove fixed nitrogen from aquatic environments and hydrologic conditions are one potential driver of denitrification rate and denitrifier community composition. In this study, two agriculturally impacted streams in the Sugar Creek watershed in Indiana, USA with different hydrologic regimes were examined; one stream is seasonally ephemeral because of its source (tile drainage, whereas the other stream has permanent flow. Additionally, a simulated flooding experiment was performed on the riparian benches of the ephemeral stream during a dry period. Denitrification activity was assayed using the chloramphenicol amended acetylene block method and bacterial communities were examined based on quantitative PCR and terminal restriction length polymorphisms of the nitrous oxide reductase (nosZ and 16S rRNA genes. In the stream channel, hydrology had a substantial impact on denitrification rates, likely by significantly lowering water potential in sediments. Clear patterns in denitrification rates were observed among pre-drying, dry, and post-drying dates; however, a less clear scenario was apparent when analyzing bacterial community structure suggesting that denitrifier community structure and denitrification rate were not strongly coupled. This implies that the nature of the response to short-term hydrologic changes was physiological rather than increases in abundance of denitrifiers or changes in composition of the denitrifier community. Flooding of riparian bench soils had a short-term, transient effect on denitrification rate. Our results imply that brief flooding of riparian zones is unlikely to contribute substantially to removal of nitrate (NO3- and that seasonal drying of stream channels has a negative impact on NO3- removal, particularly because of the time lag required for denitrification to rebound. This time lag is presumably attributable to the time required for the denitrifiers to respond physiologically rather than a change

  9. Drainage pits in cohesionless materials: implications for surface of Phobos.

    Horstman, K C; Melosh, H J


    Viking orbiter images show grooves and chains of pits crossing the surface of Phobos, many of which converge toward the large crater Stickney or its antipode. Although it has been proposed that the pits and grooves are chains of secondary craters, their morphology and geometric relations suggest that they are the surface traces of fractures in the underlying solid body of Phobos. Several models have been proposed to explain the pits, of which the most plausible are gas venting and drainage of regolith into open fractures. the latter mechanism is best supported by the image data and is the mechanism studied in this investigation. Drainage pits and fissures are modeled experimentally by using two rigid substrate plates placed edge to edge and covered by uniform thicknesses of dry fragmental debris (simulated regolith). Fracture extension is simulated by drawing the plates apart, allowing drainage of regolith into the newly created void. A typical drainage experiment begins with a shallow depression on the surface of the regolith, above the open fissure. Increased drainage causes local drainage pits to form; continued drainage causes the pits to coalesce, forming a cuspate groove. The resulting experimental patterns of pits and grooves have pronounced similarities to those observed on Phobos. Characteristics such as lack of raised rims, linearity of grooves and chains of pits, uniform spacing of pits, and progression from discrete pits to cuspate grooves are the same in the experiments and on Phobos. In contrast, gas-venting pits occur in irregular chains and have raised rims. These experiments thus indicate that the Phobos grooves and pits formed as drainage structures. The pit spacing in an experiment is measured at the time that the maximum number of pits forms, prior to groove development. The average pit spacing is compared to the regolith thickness for each material. Regression line fits indicate that the average spacing of drainage pits in unconsolidated

  10. Drainage - Structure Correlation in tectonically active Regions: Case studies in the Bolivian and Colombian Andes

    Zeilinger, Gerold; Parra, Mauricio; Kober, Florian


    It is widely accepted, that drainage patterns are often controlled by tectonics/climate and geology/rheology. Classical drainage patterns can be found 1) in fault-and-thrust belt, where rives follow the valleys parallel or cut perpendicular to strike trough the ridges, forming a trellis pattern, 2) at dome structures where the drainage form a radial pattern or 3) rectangular patterns in strongly fractured regions. In this study, we focus on fault-and-thrust belts, that undergone different phases of tectonic activity. According to classical models, the deformation is propagating into the foreland, hence being youngest at the frontal part and getting successively older towards the axis of the orogen. Drainage patterns in the more interior parts of the orogenic wedge should be then less influenced by the direction of structures, as landscape evolution is changing to a tectonic passive stage. This relationship might represent the transience and maturity of drainage pattern evolution. Here we study drainage patterns of the Bolivian and the eastern Colombian Andes by comparing the relative orientation of the drainage network with the orogen structural grain. The drainage is extracted from Digital Elevation Models (SRTM 30 m) and indexed by their Strahler Order. Order 1 channels have an upstream area of 1 km2. The direction of all segments is analyzed by linear directional mean function that results in the mean orientation of input channels with approx. 500 m average length. The orientation of structures for different structural domains is calculated using the same function on digitized faults and fold-axis. Rose diagrams show the length-weighted directional distribution of structures, of higher (>= 4) and of lower order (tectonic activity. The only weakly preferred orientation of drainages in the interior parts (EC and IR) suggests a balance between structural control and drainage occupation, and higher maturity of the landscape. In contrast, the distinct pattern of

  11. Technical note on drainage systems

    Bentzen, Thomas Ruby

    This technical note will present simple but widely used methods for the design of drainage systems. The note will primarily deal with surface water (rainwater) which on a satisfactorily way should be transport into the drainage system. Traditional two types of sewer systems exist: A combined system......’s not major different than described below - just remember to include this contribution for combined systems where the surface water (rain) and sewage are carried in the same pipes in the system and change some of the parameters for failure allowance (this will be elaborated further later on). The technical...

  12. Nitrogen budget in the Changjiang River drainage area

    JIANG Tao; YU Zhiming; SONG Xiuxian; CAO Xihua


    We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area.Nitrogen inputs in the budget included N from synthetic fertilizer,biological fixation by leguminous and other crops,wet/dry atmospheric deposition,excreta from humans and animals,and crop residues.The total N input was estimated to be 17.6 Tg,of which 20% or 3.5 Tg N was transported into waterbodies.Of the total N transported into waterbodies,the largest proportion was N from animal waste (26%),followed by N from atmospheric wet/dry deposition (25%),synthetic fertilizer N (17%),N in sewage wastes (17%),N in human waste from rural areas (6%) and industrial wastewater N (9%).We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins,from upstream to downstream:the Tongtian River drainage area (TTD,the headwater drainage area,138 000 km2,less disturbed by human activities); the Jinsha River drainage area (JSD,347 000 km2,less disturbed by human activities,approx.3 500 km upstream of the Changjiang estuary); the Pingshan-Yichang drainage area (PYD,520 500 km2,large-scale human disturbance,about 2 000 km upstream of the Changjiang estuary);and the Yichang-Datong drainage area (YDD,699 900 km2,large-scale human disturbance,approx.620 km upstream of the Changjiang estuary).The average N input into waterbodies was 2.3,7.3,24.1,and 28.2 kg N/ha in the TTD,JSD,PYD,and YDD sub-basins,respectively,suggesting an increase of N-components of more than 10 times from upstream to downstream areas.

  13. Flood-frequency characteristics of Wisconsin streams

    Walker, John F.; Peppler, Marie C.; Danz, Mari E.; Hubbard, Laura E.


    Flood-frequency characteristics for 360 gaged sites on unregulated rural streams in Wisconsin are presented for percent annual exceedance probabilities ranging from 0.2 to 50 using a statewide skewness map developed for this report. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of the equations presented in this report. The State was divided into eight areas of similar physiographic characteristics. The most significant basin characteristics are drainage area, soil saturated hydraulic conductivity, main-channel slope, and several land-use variables. The standard error of prediction for the equation for the 1-percent annual exceedance probability flood ranges from 56 to 70 percent for Wisconsin Streams; these values are larger than results presented in previous reports. The increase in the standard error of prediction is likely due to increased variability of the annual-peak discharges, resulting in increased variability in the magnitude of flood peaks at higher frequencies. For each of the unregulated rural streamflow-gaging stations, a weighted estimate based on the at-site log Pearson type III analysis and the multiple regression results was determined. The weighted estimate generally has a lower uncertainty than either the Log Pearson type III or multiple regression estimates. For regulated streams, a graphical method for estimating flood-frequency characteristics was developed from the relations of discharge and drainage area for selected annual exceedance probabilities. Graphs for the major regulated streams in Wisconsin are presented in the report.

  14. Hydrologic assessment of three drainage basins in the Pinelands of southern New Jersey, 2004-06

    Walker, Richard L.; Nicholson, Robert S.; Storck, Donald A.


    The New Jersey Pinelands is an ecologically diverse area in the southern New Jersey Coastal Plain, most of which overlies the Kirkwood-Cohansey aquifer system. The demand for groundwater from this aquifer system is increasing as local development increases. Because any increase in groundwater withdrawals has the potential to affect streamflows and wetland water levels, and ultimately threaten the ecological health and diversity of the Pinelands ecosystem, the U.S. Geological Survey, in cooperation with the New Jersey Pinelands Commission, began a multi-phase hydrologic investigation in 2004 to characterize the hydrologic system supporting the aquatic and wetland communities of the New Jersey Pinelands area (Pinelands). The current investigation of the hydrology of three representative drainage basins in the Pinelands (Albertson Brook, McDonalds Branch, and Morses Mill Stream basins) included a compilation of existing data; collection of water-level and streamflow data; mapping of the water-table altitude and depth to the water table; and analyses of water-level and streamflow variability, subsurface gradients and flow patterns, and water budgets. During 2004-06, a hydrologic database of existing and new data from wells and stream sites was compiled. Methods of data collection and analysis were defined, and data networks consisting of 471 wells and 106 surface-water sites were established. Hydrographs from 26 water-level-monitoring wells and four streamflow-gaging stations were analyzed to show the response of water levels and streamflow to precipitation and recharge with respect to the locations of these wells and streams within each basin. Water-level hydrographs show varying hydraulic gradients and flow potentials, and indicate that responses to recharge events vary with well depth and proximity to recharge and discharge areas. Results of the investigation provide a detailed characterization of hydrologic conditions, processes, and relations among the components

  15. Cellular Subcompartments through Cytoplasmic Streaming.

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


    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.

  16. Percutaneous drainage of abdominal abcess

    Men, Sueleyman E-mail:; Akhan, Okan; Koeroglu, Mert


    The mortality in undrained abdominal abscesses is high with a mortality rate ranging between 45 and 100%. The outcome in abdominal abscesses, however, has improved due to advances in image guided percutaneous interventional techniques. The main indications for the catheter drainage include treatment or palliation of sepsis associated with an infected fluid collection, and alleviation of the symptoms that may be caused by fluid collections by virtue of their size, like pancreatic pseudocele or lymphocele. The single liver abscesses may be drained with ultrasound guidance only, whereas the multiple abscesses usually require computed tomography (CT) guidance and placement of multiple catheters. The pancreatic abscesses are generally drained routinely and urgently. Non-infected pancreatic pseudocysts may be simply observed unless they are symptomatic or cause problems such as pain or obstruction of the biliary or the gastrointestinal tract. Percutaneous routes that have been described to drain pelvic abscesses include transrectal or transvaginal approach with sonographic guidance, a transgluteal, paracoccygeal-infragluteal, or perineal approach through the greater sciatic foramen with CT guidance. Both the renal and the perirenal abscesses are amenable to percutaneous drainage. Percutaneous drainage provides an effective and safe alternative to more invasive surgical drainage in most patients with psoas abscesses as well.

  17. How sulfate-rich mine drainage affected aquatic ecosystem degradation in northeastern China, and potential ecological risk.

    Zhao, Qian; Guo, Fen; Zhang, Yuan; Ma, Shuqin; Jia, Xiaobo; Meng, Wei


    Mining activity is an increasingly important stressor for freshwater ecosystems. However, the mechanism on how sulfate-rich mine drainage affects freshwater ecosystems is largely unknown, and its potential ecological risk has not been assessed so far. During 2009-2016, water and macroinvertebrate samples from 405 sample sites were collected along the mine drainage gradient from circum-neutral to alkaline waters in Hun-Tai River, Northeastern China. Results of linear regressions showed that sulfate-rich mine drainage was significantly positively correlated with the constituents typically derived from rock weathering (Ca(2+), Mg(2+) and HCO3(-)+CO3(2-)); the diversity of intolerant stream macroinvertebrates exhibited a steep decline along the gradient of sulfate-rich mine drainage. Meanwhile, stressor-response relationships between sulfate-rich mine drainage and macroinvertebrate communities were explored by two complementary statistical approaches in tandem (Threshold Indicator Taxa Analysis and the field-based method developed by USEPA). Results revealed that once stream sulfate concentrations in mine drainage exceeded 35mg/L, significant decline in the abundance of intolerant macroinvertebrate taxa occurred. An assessment of ecological risk posed by sulfate-rich mine drainage was conducted based on a tiered approach consisting of simple deterministic method (Hazard Quotient, HQ) to probabilistic method (Joint Probability Curve, JPC). Results indicated that sulfate-rich mine drainage posed a potential risk, and 64.62-84.88% of surface waters in Hun-Tai River exist serious risk while 5% threshold (HC05) and 1% threshold (HC01) were set up to protect macroinvertebrates, respectively. This study provided us a better understanding on the impacts of sulfate-rich mine drainage on freshwater ecosystems, and it would be helpful for future catchment management to protect streams from mining activity. Copyright © 2017. Published by Elsevier B.V.

  18. Streamflow, a GIS-based Environmental Assessment Tool for Lowland Streams

    Pieterse, N.M.; Olde Venterink, H.; Schot, P.P.; Verkroost, A.W.M.


    Human activities, such as stream management, drainage, urbanization and agriculture, heavily influence the aquatic ecosystems in small lowland streams. For the assessment of the impact of human activities of aquatic ecosystems, a modeling tool is created. This modeling tool is part of the EU-life Do

  19. Definition of the drainage filter problem

    Zaslavsky, D.


    It is common to consider the following: I. Retention of soil particles that may enter the drainage pipe and cause its clogging. For some sensitive structures it is important to prevent settlements due to soil transportation by drainage water.

  20. Acoustic streaming enhanced electrodeposition of nickel

    Jensen, Jens Dahl; Møller, Per


    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....

  1. Percutaneous catheter drainage of intrapulmonary fluid collection

    Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H. [Gyeongsang National University Hospital, Chinju (Korea, Republic of)


    With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment.

  2. Evaluation of the sustainability of road drainage systems

    García-Diez, Iván; Palencia, Covadonga; Fernández Raga, María


    Water is the most erosive agent that exists on the linear structures, because they are constantly subjected to outdoor condition like irregular infiltration, frosts and different rain intensities. Another variables that highly influence in the entire lifetime of a natural drainage system are the spatial and temporal variability of the rainfall, the soil, the vegetation cover and the design. All this factors are affecting the vulnerability of the clearings and embankments, by wearing away the weakest materials which surround the roads or train rails, producing erosion and very bumpy surfaces. The result is that the original pattern, developped to disminished the lost of soil, is not properly working and it cannot eliminate water, with the consequence destruction of the linear structure after several rainfall periods, and the accumulation of material down slope. The propose of this research focuses on analysing the drainage systems used in spanish roads and railways lines. For this purpose, a revision of the literature has been done, and the main drainage solutions have been recovered, carrying out an evaluation of them from an environmental point of view. This procedure has been requested by several authors in the past (Nwa, E.U. & Twocock, J.G., 1969; Goulter, I.C., 1992), together with the need of designing a more sustainable drainage system. The final objective of this complete revision is to compare objetively the designs to valuate them in order to develop a new drainage patter which minimize the erosion, increasing the durability and effectiveness of the drainage system. For this purpose, it is neccesary to assure that all the systems will be compare under similar parameters of flow rate, vegetation, substrate, lenght, slope and total section. Only the channels pattern and water distribution will change. The analysis has been done following Liu, H. & Zhu, X.B., (2012), who pointed out that the main parameters to take into account to select a road drainage

  3. Anatomy of a meltwater drainage system beneath the ancestral East Antarctic ice sheet

    Simkins, Lauren M.; Anderson, John B.; Greenwood, Sarah L.; Gonnermann, Helge M.; Prothro, Lindsay O.; Halberstadt, Anna Ruth W.; Stearns, Leigh A.; Pollard, David; Deconto, Robert M.


    Subglacial hydrology is critical to understand the behaviour of ice sheets, yet active meltwater drainage beneath contemporary ice sheets is rarely accessible to direct observation. Using geophysical and sedimentological data from the deglaciated western Ross Sea, we identify a palaeo-subglacial hydrological system active beneath an area formerly covered by the East Antarctic ice sheet. A long channel network repeatedly delivered meltwater to an ice stream grounding line and was a persistent pathway for episodic meltwater drainage events. Embayments within grounding-line landforms coincide with the location of subglacial channels, marking reduced sedimentation and restricted landform growth. Consequently, channelized drainage at the grounding line influenced the degree to which these landforms could provide stability feedbacks to the ice stream. The channel network was connected to upstream subglacial lakes in an area of geologically recent rifting and volcanism, where elevated heat flux would have produced sufficient basal melting to fill the lakes over decades to several centuries; this timescale is consistent with our estimates of the frequency of drainage events at the retreating grounding line. Based on these data, we hypothesize that ice stream dynamics in this region were sensitive to the underlying hydrological system.

  4. Stream piracy in the Black Hills: A geomorphology lab exercise

    Zaprowski, B.J.; Evenson, E.B.; Epstein, J.B.


    The Black Hills of South Dakota exhibits many fine examples of stream piracy that are very suitable for teaching geomorphology lab exercises. This lab goes beyond standard topographic map interpretation by using geologic maps, well logs, gravel provenance and other types of data to teach students about stream piracy. Using a step-by-step method in which the lab exercises ramp up in difficulty, students hone their skills in deductive reasoning and data assimilation. The first exercises deal with the identification of stream piracy at a variety of spatial scales and the lab culminates with an exercise on landscape evolution and drainage rearrangement.

  5. Sources and transformations of nitrate from streams draining varying land uses: Evidence from dual isotope analysis

    Burns, Douglas A.; Boyer, E.W.; Elliott, E.M.; Kendall, C.


    Knowledge of key sources and biogeochemical processes that affect the transport of nitrate (NO3-) in streams can inform watershed management strategies for controlling downstream eutrophication. We applied dual isotope analysis of NO3- to determine the dominant sources and processes that affect NO3- concentrations in six stream/river watersheds of different land uses. Samples were collected monthly at a range of flow conditions for 15 mo during 2004-05 and analyzed for NO3- concentrations, ?? 15NNO3, and ??18ONO3. Samples from two forested watersheds indicated that NO3- derived from nitrification was dominant at baseflow. A watershed dominated by suburban land use had three ??18ONO3 values greater than +25???, indicating a large direct contribution of atmospheric NO 3- transported to the stream during some high flows. Two watersheds with large proportions of agricultural land use had many ??15NNO3 values greater than +9???, suggesting an animal waste source consistent with regional dairy farming practices. These data showed a linear seasonal pattern with a ??18O NO3:??15NNO3 of 1:2, consistent with seasonally varying denitrification that peaked in late summer to early fall with the warmest temperatures and lowest annual streamflow. The large range of ?? 15NNO3 values (10???) indicates that NO 3- supply was likely not limiting the rate of denitrification, consistent with ground water and/or in-stream denitrification. Mixing of two or more distinct sources may have affected the seasonal isotope patterns observed in these two agricultural streams. In a mixed land use watershed of large drainage area, none of the source and process patterns observed in the small streams were evident. These results emphasize that observations at watersheds of a few to a few hundred km2 may be necessary to adequately quantify the relative roles of various NO 3- transport and process patterns that contribute to streamflow in large basins. Copyright ?? 2009 by the American Society of

  6. Nocturnal drainage wind characteristics in two converging air sheds

    Gedayloo, T.; Clements, W.E.; Barr, S.; Archuleta, J.A.


    During the short experimental period in the Grants Basin of Northeastern New Mexico a survey was conducted on the complex meteorology of this area. Emphasis was placed on the nocturnal drainage flow because of the potential hazards to the populated areas of Milan and Grants from the effluents of the uranium mining and milling operation in this area. This investigation has shown that the nocturnal drainage flow patterns agree with the winds predicted on the basis of the complex terrain of the area. Because of the surface cooling at night (over 25/sup 0/C during summer and about 20/sup 0/C during winter), air from elevated surrounding areas flows to the low lying regions consequently setting up a nocturnal drainage flow. This regime exists over 60% of the time during summer months and over 65% of the time during winter months with a depth generally less than 200 m. In the San Mateo air shed the drainage flow is east northeast, and in the Ambrosia Lake air shed it is from northwest. The confluence of these two air flows contributes mainly to the drainage flow through the channel formed by La Ja Mesa and Mesa Montanosa. The analysis of data collected by the recording Flats Station confirms the prediction that although the area south of the channel region broadens considerably causing a reduction in flow speed, contributions from the southside of La Jara Mesa and Mesa Montanosa partly compensate for this reduction. The position of this recording station is 15 to 20 km from the populated towns of Milan and Grants. A drainage flow speed of approximately 2.2 m s/sup -1/ and the duration of over 11 hours as recorded by this station indicates that air from the San Mateo and Ambrosia Lake regions may be transported southwards to these population centers during a nocturnal period. In order to test this prediction, a series of multi-atmospheric tracer experiments were conducted in the Grants Basin.

  7. Introduction to stream: An Extensible Framework for Data Stream Clustering Research with R

    Michael Hahsler


    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.

  8. EUS-Guided Biliary Drainage

    Marc Giovannini


    Full Text Available The echoendoscopic biliary drainage is an option to treat obstructive jaundices when ERCP drainage fails. These procedures compose alternative methods to the side of surgery and percutaneous transhepatic biliary drainage, and it was only possible by the continuous development and improvement of echoendoscopes and accessories. The development of linear setorial array echoendoscopes in early 1990 brought a new approach to diagnostic and therapeutic dimenion on echoendoscopy capabilities, opening the possibility to perform punction over direct ultrasonographic view. Despite of the high success rate and low morbidity of biliary drainage obtained by ERCP, difficulty could be found at the presence of stent tumor ingrown, tumor gut compression, periampulary diverticula, and anatomic variation. The echoendoscopic technique starts performing punction and contrast of the left biliary tree. When performed from gastric wall, the access is made through hepatic segment III. From duodenum, direct common bile duct punction. Dilatation is required before stent introduction, and a plastic or metallic stent is introduced. This phrase should be replaced by: diathermic dilatation of the puncturing tract is required using a 6F cystostome. The technical success of hepaticogastrostomy is near 98%, and complications are present in 36%: pneumoperitoneum, choleperitoneum, infection, and stent disfunction. To prevent bile leakage, we have used the 2 stent techniques, the first stent introduced was a long uncovered metallic stent (8 or 10 cm, and inside this first stent a second fully covered stent of 6 cm was delivered to bridge the bile duct and the stomach. Choledochoduodenostomy overall success rate is 92% and described complications include, in frequency order, pneumoperitoneum and focal bile peritonitis, present in 19%. By the last 10 years, the technique was especially performed in reference centers, by ERCP experienced groups, and this seems to be a general

  9. Antifungal Susceptibility Patterns, In Vitro Production of Virulence Factors, and Evaluation of Diagnostic Modalities for the Speciation of Pathogenic Candida from Blood Stream Infections and Vulvovaginal Candidiasis

    Chaitanya Tellapragada


    Full Text Available Candida spp. have emerged as successful pathogens in both invasive and mucosal infections. Varied virulence factors and growing resistance to antifungal agents have contributed to their pathogenicity. We studied diagnostic accuracy of HiCrome Candida Differential Agar and Vitek 2 Compact system for identification of Candida spp. in comparison with species-specific PCR on 110 clinical isolates of Candida from blood stream infections (54, 49% and vulvovaginal candidiasis (56, 51%. C. albicans (61% was the leading pathogen in VVC, while C. tropicalis (46% was prominent among BSIs. HiCrome Agar and Vitek 2 Compact had good measures of agreement (κ 0.826 and 0.895, respectively, in comparison with PCR. We also tested these isolates for in vitro production of proteinase, esterase, phospholipases, and biofilms. Proteinase production was more among invasive isolates (P=0.017, while phospholipase production was more among noninvasive isolates (P=0.001. There was an overall increase in the production of virulence factors among non-albicans Candida. Identification of clinical isolates of Candida up to species level either by chromogenic agar or by Vitek 2 Compact system should be routinely done to choose appropriate therapy.

  10. Nutrient enrichment effect on macroinvertebrates in a lowland stream of Argentina

    Agustina Cortelezzi


    Full Text Available ABSTRACT One of the most important effects derived from the intensive land use is the increase of nutrient concentration in the aquatic systems due to superficial drainage. Besides, the increment of precipitations in South America connected to the global climate change could intensify these anthropic impacts due to the changes in the runoff pattern and a greater discharge of water in the streams and rivers. The pampean streams are singular environments with high natural nutrient concentrations which could be increased even more if the predictions of global climate change for the area are met. In this context, the effect of experimental nutrient addition on macroinvertebrates in a lowland stream is studied. Samplings were carried out from March 2007 to February 2009 in two reaches (fertilized and unfertilized, upstream and downstream from the input of nutrients. The addition of nutrients caused an increase in the phosphorus concentration in the fertilized reach which was not observed for nitrogen concentration. From all macroinvertebrates studied only two taxa had significant differences in their abundance after fertilization: Corbicula fluminea and Ostracoda. Our results reveal that the disturbance caused by the increase of nutrients on the benthic community depends on basal nutrients concentration. The weak response of macroinvertebrates to fertilization in the pampean streams could be due to their tolerance to high concentrations of nutrients in relation to their evolutionary history in streams naturally enriched with nutrients. Further research concerning the thresholds of nutrients affecting macroinvertebrates and about the adaptive advantages of taxa in naturally eutrophic environments is still needed. This information will allow for a better understanding of the processes of nutrient cycling and for the construction of restoration measures in natural eutrophic ecosystems.

  11. Continuous Passive Sampling of Solutes from Agricultural Subsurface Drainage Tubes

    Lindblad Vendelboe, Anders; de Jonge, Hubert; Rozemeijer, Joachim; Wollesen de Jonge, Lis


    Agricultural subsurface tube drain systems play an important role in water and solute transport. One study, focusing on lowland agricultural catchments, showed that subsurface tube drainage contributed up to 80% of the annual discharge and 90% of the annual NO3 load from agricultural fields to the receiving water bodies. Knowledge of e.g. nutrient loads and drainage volumes, based on measurements and modelling, are important for adequate water quality management. Despite the importance of tube drain transport of solutes, monitoring data are scarce. This scarcity is a result of the existing monitoring techniques for flow and contaminant load from tube drains being expensive and labor-extensive. The study presented here aimed at developing a cheap, simple, and robust method to monitor solute loads from tube drains. The method is based on the newly developed Flowcap, which can be attached to existing tube drain outlets and can measure total flow, contaminant load and flow-averaged concentrations of solutes in the drainage. The Flowcap builds on the existing Sorbicell principle, a passive sampling system that measures average concentrations over longer periods of time (days to months) for various compounds. The Sorbicell consists of two compartments permeable to water. One compartment contains an adsorbent and one contains a tracer. When water passes through the Sorbicell the compound of interest is absorbed while a tracer is released. Using the tracer loss to calculate the volume of water that has passed the Sorbicell it is possible to calculate the average concentration of the compound. When mounting Sorbicells in the Flowcap, a flow-proportional part of the drainage is sampled from the main stream. To accommodate the wide range of drainage flow rates two Flowcaps with different capacities were tested in the laboratory: one with a capacity of 25 L min-1 (Q25) and one with a capacity of 256 L min-1 (Q256). In addition, Sorbicells with two different hydraulic

  12. Network Characteristics of Video Streaming Traffic

    Rao, Ashwin; Barakat, Chadi; Legout, Arnaud; Towsley, Don; Dabbous, Walid


    Video streaming represents a large fraction of Internet traffic. Surprisingly, little is known about the network characteristics of this traffic. In this paper, we study the network characteristics of the two most popular video streaming services, Netflix and YouTube. We show that the streaming strategies vary with the type of the application (Web browser or native mobile application), and the type of container (Silverlight, Flash, or HTML5) used for video streaming. In particular, we identify three different streaming strategies that produce traffic patterns from non-ack clocked ON-OFF cycles to bulk TCP transfer. We then present an analytical model to study the potential impact of these streaming strategies on the aggregate traffic and make recommendations accordingly.

  13. Reconstruction of North American drainage basins and river discharge since the Last Glacial Maximum

    Wickert, Andrew D.


    Over the last glacial cycle, ice sheets and the resultant glacial isostatic adjustment (GIA) rearranged river systems. As these riverine threads that tied the ice sheets to the sea were stretched, severed, and restructured, they also shrank and swelled with the pulse of meltwater inputs and time-varying drainage basin areas, and sometimes delivered enough meltwater to the oceans in the right places to influence global climate. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges, by combining models of past ice sheets, glacial isostatic adjustment, and climate. The result is a time series of synthetic paleohydrographs and drainage basin maps from the Last Glacial Maximum to present for nine major drainage basins - the Mississippi, Rio Grande, Colorado, Columbia, Mackenzie, Hudson Bay, Saint Lawrence, Hudson, and Susquehanna/Chesapeake Bay. These are based on five published reconstructions of the North American ice sheets. I compare these maps with drainage reconstructions and discharge histories based on a review of observational evidence, including river deposits and terraces, isotopic records, mineral provenance markers, glacial moraine histories, and evidence of ice stream and tunnel valley flow directions. The sharp boundaries of the reconstructed past drainage basins complement the flexurally smoothed GIA signal that is more often used to validate ice-sheet reconstructions, and provide a complementary framework to reduce nonuniqueness in model reconstructions of the North American ice-sheet complex.

  14. Influence of land-use on structural and functional macroinvertebrate composition communities associated on detritus in Subtropical Atlantic Forest streams

    Luiz Ubiratan Hepp

    Full Text Available Abstract Aim Our aim in this study was to evaluate the effects of land use in drainage basins of the streams on the taxonomic and functional composition of aquatic invertebrate communities associated in leaf litter. Methods We evaluated the colonisation of invertebrates in the incubated plant debris in streams with presence and absence of riparian vegetation and different land-uses in the drainage area. We used the litter bags approach. Results The taxonomic and functional composition invertebrate associated with leaf litter ranged between streams. In addition, streams with presence of vegetation showed less variation taxonomic and functional composition communities. Still, the density of shredders invertebrates were lower in streams without vegetation. Conclusions The riparian vegetation is an important environmental factor in the composition of invertebrates. However, the land-use throughout the drainage basin should be considered as relevant factor in structuring aquatic biota.

  15. Vertical drainage capacity of new electrical drainage board on improvement of super soft clayey ground

    沈扬; 励彦德; 黄文君; 徐海东; 胡品飞


    As an advanced polymer composites electro-kinetic geosynthetics, the electro-osmotic vertical drainage (EVD) board could drain water quickly and accelerate consolidation process. However, the drainage rate was mainly impacted by the vertical drainage capability. Therefore, vertical drainage capability at the top of EVD board was theoretically analyzed. Basic requirements for drainage at the top of the board were summed up, as well as the formula of anode pore pressure when losing the vertical drainage capability. Meanwhile, a contrast test on the top and bottom drainage capacities was conducted. In use of the advanced EVD board, the voltage potential and pore pressure of anode were measured. Moreover, the derived formulas were verified. The result shows that the decrease of electric force gradient had an observable impact on the drainage capability. There was nearly no difference between the energy consumption for the two drainage methods. Although a little less water was discharged, the top drainage method had more advantages, such as high initial drainage velocity, few soil cracks, low anode water content and high soil strength. All of these show that the super soft soil ground could be consolidated quickly in use of the advanced EVD board through the top drainage. The top drainage method could efficiently improve the drainage effect, decrease the energy consumption and speed up the project proceeding.

  16. The ecology of chalk-stream invertebrates studied in a recirculating stream


    To study and qualify the factors influencing interactions between various trophic levels in natural hard-water streams, a recirculating artificial stream channel was constructed. This structure has enabled patterns of population change of stream fauna to be observed under partially controlled physical and chemical conditions. Initial colonization of the substratum by invertebrates and subsequent succession was studied along with depth distribution and growth and production studies of inverteb...

  17. Riparian and in-stream controls on nutrient concentrations along a headwater forested stream

    S. Bernal


    Full Text Available Headwater streams have a strong capacity to transform and retain nutrients, and thus, a longitudinal decrease in stream nutrient concentrations would be expected from in-stream nutrient removal alone. Yet, a number of other factors within the catchment, including biogeochemical processing within the riparian zone and export to streams, can contribute to stream nutrient concentration, which may overcome the effect of in-stream biogeochemical processing. To explore this idea, we analyzed the longitudinal patterns of stream and riparian groundwater concentrations for chloride (Cl−, nitrate (NO3−, ammonium (NH4+, and phosphate (PO43− along a 3.7 km reach at an annual scale. The reach showed a gradual increase in stream and riparian width, riparian tree basal area, and abundance of riparian N2-fixing tree species. Concentrations of Cl− indicated a~strong hydrological connection at the riparian-stream edge. However, stream and riparian groundwater nutrient concentrations showed a moderate to null correlation, suggesting high biogeochemical processing at the riparian-stream edge and within the stream. A mass balance approach along the reach indicated that, on average, in-stream net nutrient uptake prevailed over release for NH4+ and PO43−, but not for NO3−. On an annual basis, in-stream processes contributed to change stream input fluxes by 11%, 26%, and 29% for NO3−, NH4+, and PO43−, respectively. Yet, longitudinal trends in concentration were not consistent with the prevailing in-stream biogeochem ical processes. During the riparian dormant period, stream concentration decreased along the reach for NO3−, but increased for NH4+ and PO43−. During the riparian vegetative period, NO3− and PO43− increased along the reach while NH4+ showed no clear pattern. These longitudinal trends were partially related to riparian forest features and groundwater inputs, especially for NO3− and PO43−. Our study

  18. Measurements of coarse particulate organic matter transport in steep mountain streams and estimates of decadal CPOM exports

    Bunte, Kristin; Swingle, Kurt W.; Turowski, Jens M.; Abt, Steven R.; Cenderelli, Daniel A.


    Coarse particulate organic matter (CPOM) provides a food source for benthic organisms, and the fluvial transport of CPOM is one of the forms in which carbon is exported from a forested basin. However, little is known about transport dynamics of CPOM, its relation to discharge, and its annual exports from mountain streams. Much of this knowledge gap is due to sampling difficulties. In this study, CPOM was sampled over one-month snowmelt high flow seasons in two high-elevation, subalpine, streams in the Rocky Mountains. Bedload traps developed for sampling gravel bedload were found to be suitable samplers for CPOM transport. CPOM transport rates were well related to flow in consecutive samples but showed pronounced hysteresis over the diurnal fluctuations of flow, between consecutive days, and over the rising and falling limbs of the high-flow season. In order to compute annual CPOM load, hysteresis effects require intensive sampling and establishing separate rating curves for all rising and falling limbs. Hysteresis patterns of CPOM transport relations identified in the well-sampled study streams may aid with estimates of CPOM transport and export in less well-sampled Rocky Mountain streams. Transport relations for CPOM were similar among three high elevation mountain stream with mainly coniferous watersheds. Differences among streams can be qualitatively attributed to differences in CPOM contributions from litter fall, from the presence of large woody debris, its grinding into CPOM sized particles by gravel-cobble bedload transport, hillslope connectivity, drainage density, and biological consumption. CPOM loads were 3.6 and 3.2 t/yr for the two Rocky Mountain streams. Adjusted to reflect decadal averages, values increased to 11.3 and 10.2 t/yr. CPOM yields related to the entire watershed were 2.7 and 4 kg/ha/yr for the years studied, but both streams exported similar amounts of 6.5 and 6.6 kg/ha/yr when taking the forested portion of the watershed into account. To

  19. Simulation of flood hydrographs for Georgia streams

    Inman, Ernest J.


    Flood hydrographs are needed for the design of many highway drainage structures and embankments. A method for simulating these flood hydrographs at ungaged sites in Georgia is presented in this report. The O'Donnell method was used to compute unit hydrographs and lagtimes for 355 floods at 80 gaging stations. An average unit hydrograph and an average lagtime were computed for each station. These average unit hydrographs were transformed to unit hydrographs having durations of one-fourth, one-third, one-half, and three-fourths lagtime, then reduced to dimensionless terms by dividing the time by lagtime and the discharge by peak discharge. Hydrographs were simulated for these 355 floods and their widths were compared with the widths of the observed hydrographs at 50 and 75 percent of peak flow. The dimensionless hydrograph based on one-half lagtime duration provided the best fit of the observed data. Multiple regression analysis was then used to define relations between lagtime and certain physical basin characteristics; of these characteristics, drainage area and slope were found to be significant for the rural-stream equations and drainage area, slope, and impervious area were found to be significant for the Atlanta urban-stream equation. A hydrograph can be simulated from the dimensionless hydrograph, the peak discharge of a specific recurrence interval, and the lagtime obtained from regression equations for any site in Georgia having a drainage area of less than 500 square miles. For simulating hydrographs at sites having basins larger than 500 square miles, the U.S. Geological Survey computer model CONROUT can be used. This model routes streamflow from an upstream channel location to a user-defined location downstream. The product of CONROUT is a simulated discharge hydrograph for the downstream site that has a peak discharge of a specific recurrence interval.

  20. Mine Drainage Generation and Control Options.

    Wei, Xinchao; Rodak, Carolyn M; Zhang, Shicheng; Han, Yuexin; Wolfe, F Andrew


    This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention, and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization, and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment, and a new subsection on beneficial uses for mine drainage and treatment wastes.

  1. [Simple cholecystectomy without drainage. A dilemma?].

    Macellari, G; Baraldi, U; Giustina, A; David, P; Parigi, M; De Angelis, E


    A retrospective study was carried out to show the uselessness of the routine employment of the drainage after simple cholecystectomy. 1425 patients underwent cholecystectomy because for cholelithiasis; of these 164 (13%) were drained because of adhesions, concomitant pancreatitis, inadvertent damage, empiema, gangrena and perforation of the gallbladder. In no case of the 1261 patients without drainage it has been possible to demonstrate the presence of one of those complications for which the use of a drainage after simple cholecystectomy is commonly advised.

  2. Experimental investigation of acoustic streaming in a cylindrical wave guide up to high streaming Reynolds numbers.

    Reyt, Ida; Bailliet, Hélène; Valière, Jean-Christophe


    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.

  3. Fish communities of fixed sites in the Western Lake Michigan Drainages, Wisconsin and Michigan, 1993-95

    Sullivan, D.J.


    Fish communities were surveyed at 20 wadable stream sites during 1993-95 as part of the U.S. Geological Survey's (USGS) National Water- Quality Assessment (NAWQA) Program's assessment of the Western Lake Michigan Drainages. Part of the NAWQA design is to incorporate ecological data into an overall environmental assessment. Collection of fish-community data was part of this ecological assessment.

  4. Value of ultrasound in the determination of drainage methods in patients with tuberculous pleural effusion

    Kang, Eun Young; Suh, Bo Kyoung; Shim, Jae Jeong [Korea Univ. College of Medicine, Seoul (Korea, Republic of)


    To evaluate the utility of ultrasonography (US) as a guide in deciding drainage methods and as a prognostic factor in the prediction of pleural fibrosis, and to compare the effects of drainage methods in patients with tuberculous pleural effusions. In 51 patients with tuberculous pleural effusion, US patterns of pleural effusion were classified according to degree of septa into three groups, as follows : anechoic (n=5), linear septa (n=15), and honeycomb septa (n=31). US-guided drainage methods, including thoracentesis (n=17), percutaneous catheter insertion (n=12), catheter insertion with urokinase instillation (n=22) were employed. Therapeutic effects were evaluated with follow-up chest radiographs after 3 and 6 months. Three months after the procedure, 43 of 51 effusions had drained effectively. US guided drainage failed in eight patients including two of six with linear septated effusion treated with thoracentesis, four of seven with honeycomb septated effusion treated with thoracentesis, and two of six with honeycomb septated effusion treated with catheter drainage. There was no drainage failure in patients with anechoic effusions and in patients with urokinase instillation. Late effects were assessed in 39 patients after 6 months. Follow-up radiographs available in 39 patients demonstrated pleural fibrosis with intercostal space narrowing in 7 patients with honeycomb septated effusion, 3 patients with linear septated effusion, and none of the patients with anechoic effusions. The pattern of septa seen on US could be a useful factor for determining drainage methods and predicting late results in tuberculous pleural effusion. Percutaneous catheter drainage with urokinase instillation was a good drainage modality for patients with septated pleural effusions. Pleural fibrosis is more frequently induced by septated pleural effusion than by anechoic pleural effusion.

  5. Drainage basin delineations for selected USGS streamflow-gaging stations in Virginia (Drainage_Basin)

    U.S. Geological Survey, Department of the Interior — The Drainage_Basin polygon feature class was created as a digital representation of drainage basins for more than 1,650 continuous-record streamflow-gaging stations,...

  6. Effects of land-use patterns on in-stream nitrogen in a highly-polluted river basin in Northeast China.

    Bu, Hongmei; Zhang, Yuan; Meng, Wei; Song, Xianfang


    This study investigated the effects of land-use patterns on nitrogen pollution in the Haicheng River basin in Northeast China during 2010 by conducting statistical and spatial analyses and by analyzing the isotopic composition of nitrate. Correlation and stepwise regressions indicated that land-use types and landscape metrics were correlated well with most river nitrogen variables and significantly predicted them during different sampling seasons. Built-up land use and shape metrics dominated in predicting nitrogen variables over seasons. According to the isotopic compositions of river nitrate in different zones, the nitrogen sources of the river principally originated from synthetic fertilizer, domestic sewage/manure, soil organic matter, and atmospheric deposition. Isotope mixing models indicated that source contributions of river nitrogen significantly varied from forested headwaters to densely populated towns of the river basin. Domestic sewage/manure was a major contributor to river nitrogen with the proportions of 76.4 ± 6.0% and 62.8 ± 2.1% in residence and farmland-residence zones, respectively. This research suggested that regulating built-up land uses and reducing discharges of domestic sewage and industrial wastewater would be effective methods for river nitrogen control. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. GIS Analysis of Size Relationships between Drainage Basins and Alluvial Fans

    Wright, S. N.; Scuderi, L. A.; Weissmann, G. S.; Hartley, A. J.


    Imagery from the global database of modern sedimentary basins compiled by Weissman et al. (2010) allows us to test whether a size relationship between drainage basin area and distributive fluvial system (DFS) area exists. We are testing this hypothesis using a combination of SRTM-based digital elevation models and Landsat satellite imagery in ArcGIS. Sedimentary basins are delineated by preforming a Gaussian smoothing on the DEM, followed by optimal edge detection through application of a modified Canny edge detector. The pour points defining the link between contributing hydrologic basins and these sedimentary basins are then located by generating a stream network in ArcGIS and intersecting the stream network arcs with the sedimentary basin polygons. From these pour points we delineate the adjacent contributing drainage basin using the watershed tool in ArcGIS. We manually digitize the boundary and geometry of the DFS identified for each drainage basin, using the higher resolution imagery found on Google Earth for visual confirmation if the scale or resolution of the Landsat imagery requires it. We then extract drainage basins and DFS polygon parameters and calculate areal extents in order to evaluate whether such a size relationship exists within basins, regionally across several basins, or across different basin types (e.g., endorheic vs exhoreic). A limitation of this approach is that we cannot evaluate sediment volumes, only aerial coverage. Results from this study may provide a better understanding of extrabasinal processes that control DFS shape and size.

  8. Nutrient mass balance for the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia, 1990

    McMahon, G.; Woodside, M.D.


    A 1990 nitrogen and phosphorus mass balance calculated for eight National Stream Quality Accounting Network (NASQAN) basins in the Albemarle-Pamlico Drainage Basin indicated the importance of agricultural nonpoint sources of nitrogen and phosphorus and watershed nitrogen retention and processing capabilities. Basin total nitrogen and phosphorus input estimates were calculated for atmospheric deposition (which averaged 27 percent of total nitrogen inputs and 22 percent of total phosphorus inputs); crop fertilizer (27 and 25 percent); animal-waste (22 and 50 percent, respectively); point sources (3 percent each of total nitrogen and total phosphorus inputs); and biological nitrogen fixation (21 percent of total nitrogen inputs). Highest in-stream nitrogen and phosphorus loads were measured in predominantly agricultural drainage areas. Intermediate loads were observed in mixed agricultural/urban drainage areas; the lowest loads were measured in mixed agricultural/forested drainage areas. The difference between the sum of the nutrient input categories and the sum of the instream nutrient loads and crop-harvest nutrient removal was assigned to a residual category for the basin. The residual category averaged 51 percent of total nitrogen inputs and 54 percent of total phosphorus inputs.

  9. Subsurface drainage volume reduction with drainage water management: Case studies in Ohio, USA

    One of the main contributors to poor water quality in the Mississippi River and aeral increase in the hypoxic zone in the Gulf of Mexico is intensive drainage of the cropland within the watershed. Controlled drainage has been demonstrated as an approach to curb totla drainage outflow and nutrient di...

  10. Method and apparatus of prefetching streams of varying prefetch depth

    Gara, Alan [Mount Kisco, NY; Ohmacht, Martin [Yorktown Heights, NY; Salapura, Valentina [Chappaqua, NY; Sugavanam, Krishnan [Mahopac, NY; Hoenicke, Dirk [Seebruck-Seeon, DE


    Method and apparatus of prefetching streams of varying prefetch depth dynamically changes the depth of prefetching so that the number of multiple streams as well as the hit rate of a single stream are optimized. The method and apparatus in one aspect monitor a plurality of load requests from a processing unit for data in a prefetch buffer, determine an access pattern associated with the plurality of load requests and adjust a prefetch depth according to the access pattern.

  11. Geomorphology, denudation rates, and stream channel profiles reveal patterns of mountain building adjacent to the San Andreas fault in northern California, USA

    DeLong, Stephen B.; Hilley, George E.; Prentice, Carol S.; Crosby, Christopher J.; Yokelson, Intan N.


    Relative horizontal motion along strike-slip faults can build mountains when motion is oblique to the trend of the strike-slip boundary. The resulting contraction and uplift pose off-fault seismic hazards, which are often difficult to detect because of the poor vertical resolution of satellite geodesy and difficulty of locating offset datable landforms in active mountain ranges. Sparse geomorphic markers, topographic analyses, and measurement of denudation allow us to map spatiotemporal patterns of uplift along the northern San Andreas fault. Between Jenner and Mendocino, California, emergent marine terraces found southwest of the San Andreas fault record late Pleistocene uplift rates between 0.20 and 0.45 mm yr–1 along much of the coast. However, on the northeast side of the San Andreas fault, a zone of rapid uplift (0.6–1.0 mm yr–1) exists adjacent to the San Andreas fault, but rates decay northeastward as the coast becomes more distant from the San Andreas fault. A newly dated 4.5 Ma shallow-marine deposit located at ∼500 m above sea level (masl) adjacent to the San Andreas fault is warped down to just 150 masl 15 km northeast of the San Andreas fault, and it is exposed at just 60–110 masl to the west of the fault. Landscape denudation rates calculated from abundance of cosmogenic radionuclides in fluvial sediment northeast of, and adjacent to, the San Andreas fault are 0.16–0.29 mm yr–1, but they are only 0.03–0.07 mm yr–1 west of the fault. Basin-average channel steepness and the denudation rates can be used to infer the erosive properties of the underlying bedrock. Calibrated erosion rates can then be estimated across the entire landscape using the spatial distribution of channel steepness with these erosive properties. The lower-elevation areas of this landscape that show high channel steepness (and hence calibrated erosion rate) are distinct from higher-elevation areas with systematically lower channel steepness and denudation rates

  12. Effects of land-use patterns on in-stream nitrogen in a highly-polluted river basin in Northeast China

    Bu, Hongmei, E-mail: [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China); Zhang, Yuan; Meng, Wei [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Song, Xianfang [Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101 (China)


    This study investigated the effects of land-use patterns on nitrogen pollution in the Haicheng River basin in Northeast China during 2010 by conducting statistical and spatial analyses and by analyzing the isotopic composition of nitrate. Correlation and stepwise regressions indicated that land-use types and landscape metrics were correlated well with most river nitrogen variables and significantly predicted them during different sampling seasons. Built-up land use and shape metrics dominated in predicting nitrogen variables over seasons. According to the isotopic compositions of river nitrate in different zones, the nitrogen sources of the river principally originated from synthetic fertilizer, domestic sewage/manure, soil organic matter, and atmospheric deposition. Isotope mixing models indicated that source contributions of river nitrogen significantly varied from forested headwaters to densely populated towns of the river basin. Domestic sewage/manure was a major contributor to river nitrogen with the proportions of 76.4 ± 6.0% and 62.8 ± 2.1% in residence and farmland-residence zones, respectively. This research suggested that regulating built-up land uses and reducing discharges of domestic sewage and industrial wastewater would be effective methods for river nitrogen control. - Highlights: • Land-use types were correlated well with most nitrogen variables over seasons. • Built-up land dominated in predicting nitrogen variables during different seasons. • Shape metrics predicted most nitrogen variables in different seasons. • Nitrogen sources and their contributions were estimated using nitrate isotopes. • Domestic sewage mainly contributed to river nitrogen pollution in residence zone.

  13. The effect of climate change on urban drainage

    Grum, M.; Jørgensen, A.T.; Johansen, R.M.


    and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps......: Firstly, hourly rainfall intensities from 16 point rain gauges are averaged to create a rain gauge equivalent intensity for a 25 X 25 km square corresponding to one grid cell in the climate model. Secondly, the differences between present and future in the climate model is used to project the hourly......That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent...

  14. Drainage Structure Datasets and Effects on LiDAR-Derived Surface Flow Modeling

    Ruopu Li


    Full Text Available With extraordinary resolution and accuracy, Light Detection and Ranging (LiDAR-derived digital elevation models (DEMs have been increasingly used for watershed analyses and modeling by hydrologists, planners and engineers. Such high-accuracy DEMs have demonstrated their effectiveness in delineating watershed and drainage patterns at fine scales in low-relief terrains. However, these high-resolution datasets are usually only available as topographic DEMs rather than hydrologic DEMs, presenting greater land roughness that can affect natural flow accumulation. Specifically, locations of drainage structures such as road culverts and bridges were simulated as barriers to the passage of drainage. This paper proposed a geospatial method for producing LiDAR-derived hydrologic DEMs, which incorporates data collection of drainage structures (i.e., culverts and bridges, data preprocessing and burning of the drainage structures into DEMs. A case study of GIS-based watershed modeling in South Central Nebraska showed improved simulated surface water derivatives after the drainage structures were burned into the LiDAR-derived topographic DEMs. The paper culminates in a proposal and discussion of establishing a national or statewide drainage structure dataset.

  15. Dynamics of a gravel bed stream in transition: Fishtrap Creek, British Columbia

    Phillips, J. C.; Eaton, B. C.; Giles, T.


    In August 2003, a forest fire burnt the entire floodplain and most of the contributing drainage basin of Fishtrap Creek, British Columbia. The riparian vegetation, which consisted primarily of mature cottonwoods and redcedar trees, suffered nearly 100% mortality due to the fire: none of the dead trees have since been removed, following the fire. The post-fire riparian vegetation comprises various herbaceous species, as well as some small shrubs and trees. The UBC regime model predicts that such a change in bank vegetation will result in an eventual transition from a narrow, stable, single thread stream channel to an unstable, multiple- thread channel about twice as wide as the original. During the snowmelt freshet of 2006, the first signs of significant channel change were documented in the field. We use three years of repeated cross sectional surveys and low level aerial photography from before and after the freshet to characterize the changes in channel geometry. We also documented the patterns of sediment transfer during the freshet using data from magnetic tracers. The tracers were deployed at four locations throughout the 300 m-long study reach: the distribution of transport distances for each tracer stone population were strongly conditioned by the sequence of morphologic changes occurring along the stream channel. Our results suggest that typical step lengths in gravel bed streams can be much larger than the bar-to-bar spacing and furthermore that they are quite variable, even over short distances. These results are the first stages of a long-term study of stream channel response to, and recovery from, a catastrophic disturbance. The project will eventually allow us to test and calibrate the UBC regime model and to identify the characteristic timescales associated with these sorts of channel adjustments.

  16. Overview of streaming-data algorithms

    Madhulatha, T Soni


    Due to recent advances in data collection techniques, massive amounts of data are being collected at an extremely fast pace. Also, these data are potentially unbounded. Boundless streams of data collected from sensors, equipments, and other data sources are referred to as data streams. Various data mining tasks can be performed on data streams in search of interesting patterns. This paper studies a particular data mining task, clustering, which can be used as the first step in many knowledge discovery processes. By grouping data streams into homogeneous clusters, data miners can learn about data characteristics which can then be developed into classification models for new data or predictive models for unknown events. Recent research addresses the problem of data-stream mining to deal with applications that require processing huge amounts of data such as sensor data analysis and financial applications. For such analysis, single-pass algorithms that consume a small amount of memory are critical.

  17. Overview Of Streaming-Data Algorithms

    T. Soni Madhulatha


    Full Text Available Due to recent advances in data collection techniques, massive amounts of data are being collected at anextremely fast pace. Also, these data are potentially unbounded. Boundless streams of data collected fromsensors, equipments, and other data sources are referred to as data streams. Various data mining taskscan be performed on data streams in search of interesting patterns. This paper studies a particular datamining task, clustering, which can be used as the first step in many knowledge discovery processes. Bygrouping data streams into homogeneous clusters, data miners can learn about data characteristicswhich can then be developed into classification models for new data or predictive models for unknownevents. Recent research addresses the problem of data-stream mining to deal with applications thatrequire processing huge amounts of data such as sensor data analysis and financial applications. Forsuch analysis, single-pass algorithms that consume a small amount of memory are critical.

  18. 24 CFR 3285.604 - Drainage system.


    ... § 3285.604 Drainage system. (a) Crossovers. Multi-section homes with plumbing in more than one section require drainage system crossover connections to join all sections of the home. The crossover design requirements are located in, and must be designed in accordance with, § 3280.610 of this chapter. (b)...

  19. Agricultural drainage: Towards an integrated approach

    Abdeldayem, S.; Hoevenaars, J.; Mollinga, P.P.; Scheuman, W.; Slootweg, R.; Steenbergen, van F.


    Drainage needs to reclaim its rightful position as an indispensable element in the integrated management of land and water. An integrated approach to drainage can be developed by means of systematic mapping of the functions of natural resources systems (goods and services) and the values attributed

  20. Inferring tectonic activity using drainage network and RT model: an example from the western Himalayas, India

    Sahoo, Ramendra; Jain, Vikrant


    Morphology of the landscape and derived features are regarded to be an important tool for inferring about tectonic activity in an area, since surface exposures of these subsurface processes may not be available or may get eroded away over time. This has led to an extensive research in application of the non-planar morphological attributes like river long profile and hypsometry for tectonic studies, whereas drainage network as a proxy for tectonic activity has not been explored greatly. Though, significant work has been done on drainage network pattern which started in a qualitative manner and over the years, has evolved to incorporate more quantitative aspects, like studying the evolution of a network under the influence of external and internal controls. Random Topology (RT) model is one of these concepts, which elucidates the connection between evolution of a drainage network pattern and the entropy of the drainage system and it states that in absence of any geological controls, a natural population of channel networks will be topologically random. We have used the entropy maximization principle to provide a theoretical structure for the RT model. Furthermore, analysis was carried out on the drainage network structures around Jwalamukhi thrust in the Kangra reentrant in western Himalayas, India, to investigate the tectonic activity in the region. Around one thousand networks were extracted from the foot-wall (fw) and hanging-wall (hw) region of the thrust sheet and later categorized based on their magnitudes. We have adopted the goodness of fit test for comparing the network patterns in fw and hw drainage with those derived using the RT model. The null hypothesis for the test was, the drainage networks in the fw are statistically more similar than those on the hw, to the network patterns derived using the RT model for any given magnitude. The test results are favorable to our null hypothesis for networks with smaller magnitudes (< 9), whereas for larger

  1. Prioritized Contact Transport Stream

    Hunt, Walter Lee, Jr. (Inventor)


    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. StreamCat

    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...

  3. Phylogeographic structure of Terminalia franchetii (combretaceae) in southwest China and its implications for drainage geological history.

    Zhang, Ticao; Sun, Hang


    Following the rapid uplift of the Qinghai-Tibetan Plateau, the reorganization of the major river drainages in southwest China was primarily caused by river capture events. However, the impact of these past changes in drainage patterns on the current distribution and genetic structure of the endemic flora of this region remains largely unknown. Here we report a survey of amplified fragment length polymorphism (AFLP) in Terminalia franchetii, an endemic shrub or small tree of the deep and dry-hot river valleys of this region. We surveyed AFLP variation within and among 21 populations (251 individuals) of T. franchetii, distributed disjunctively between northern and southern drainage systems. Using STRUCTURE, principal coordinates analysis, and genetic distance methods, we identified two main population genetic groups (I and II) and four subgroups within the species, as follows: (I) the Upper Jinshajiang Valley (subgroup I((north))) and the Honghe drainage area (subgroup I((south))); (II) the Middle and Lower Jinshajiang and Yalongjiang Valleys (subgroup II((north))) and the Nanpanjiang drainage area (subgroup II((south))). Genetic diversity was lower in group I than in group II. According to the genetic diversity and genetic structure results, we suggest that the modern disjunctive distribution and associated patterns of genetic structure of T. franchetii result from vicariance caused by several historical drainage capture events, involving the separation of the Upper Jinshajiang, Yalongjiang and Daduhe from the Honghe or Nanpanjiang in southwest China.

  4. Enhanced drainage and thinning of liquid films between bubbles and solids that support surface waves

    Horesh, Amihai; Morozov, Matvey; Manor, Ofer


    We study the thinning and drainage of the intermediate liquid film between a bubble and a solid surface at close proximity in the presence of a surface acoustic wave (SAW) in the solid. Specifically, we employ the diffraction of light to observe a long air bubble confined in a solid rectangular channel filled with silicone oil. This setup, constituting a two-dimensional physical model of thin film drainage, allows us to analyze the influence of a SAW on the rate of thinning of the micron-thick liquid film separating the bubble and the solid substrate. The viscous penetration of the SAW into the liquid imposes a convective drift of mass, redistributing the fluid in the film against capillary resistance and producing a net drift of liquid out of the film. The rate of drainage of liquid from the film increases by one to several orders of magnitude in comparison to the rate of drainage due to the Laplace pressure of the bubble alone. The experimental findings agree well with a newly developed theory describing the SAW-enhanced drainage as a competition between the capillary flow and SAW-induced streaming.

  5. Querying JSON Streams

    Bo, Yang


    A data stream management system (DSMS) is similar to a database management system (DBMS) but can search data directly in on-line streams. Using its mediator-wrapper approach, the extensible database system, Amos II, allows different kinds of distributed data resource to be queried. It has been extended with a stream datatype to query possibly infinite streams, which provides DSMS functionality. Nowadays, more and more web applications start to offer their services in JSON format which is a te...

  6. Stream hydraulics and temperature determine the metabolism of geothermal Icelandic streams

    Demars B. O.L.


    Full Text Available Stream ecosystem metabolism plays a critical role in planetary biogeochemical cycling. Stream benthic habitat complexity and the available surface area for microbes relative to the free-flowing water volume are thought to be important determinants of ecosystem metabolism. Unfortunately, the engineered deepening and straightening of streams for drainage purposes could compromise stream natural services. Stream channel complexity may be quantitatively expressed with hydraulic parameters such as water transient storage, storage residence time, and water spiralling length. The temperature dependence of whole stream ecosystem respiration (ER, gross primary productivity (GPP and net ecosystem production (NEP = GPP − ER has recently been evaluated with a “natural experiment” in Icelandic geothermal streams along a 5–25 °C temperature gradient. There remained, however, a substantial amount of unexplained variability in the statistical models, which may be explained by hydraulic parameters found to be unrelated to temperature. We also specifically tested the additional and predicted synergistic effects of water transient storage and temperature on ER, using novel, more accurate, methods. Both ER and GPP were highly related to water transient storage (or water spiralling length but not to the storage residence time. While there was an additional effect of water transient storage and temperature on ER (r2 = 0.57; P = 0.015, GPP was more related to water transient storage than temperature. The predicted synergistic effect could not be confirmed, most likely due to data limitation. Our interpretation, based on causal statistical modelling, is that the metabolic balance of streams (NEP was primarily determined by the temperature dependence of respiration. Further field and experimental work is required to test the predicted synergistic effect on ER. Meanwhile, since higher metabolic activities allow for higher pollutant degradation or uptake

  7. Rye cover crop and gamagrass strip effects on NO3 concentration and load in tile drainage.

    Kaspar, T C; Jaynes, D B; Parkin, T B; Moorman, T B


    A significant portion of the NO3 from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or "tiles." Previous research has shown that N fertilizer management alone is not sufficient for reducing NO3 concentrations in subsurface drainage to acceptable levels; therefore, additional approaches need to be devised. We compared two cropping system modifications for NO3 concentration and load in subsurface drainage water for a no-till corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) management system. In one treatment, eastern gamagrass (Tripsacum dactyloides L.) was grown in permanent 3.05-m-wide strips above the tiles. For the second treatment, a rye (Secale cereale L.) winter cover crop was seeded over the entire plot area each year near harvest and chemically killed before planting the following spring. Twelve 30.5x42.7-m subsurface-drained field plots were established in 1999 with an automated system for measuring tile flow and collecting flow-weighted samples. Both treatments and a control were initiated in 2000 and replicated four times. Full establishment of both treatments did not occur until fall 2001 because of dry conditions. Treatment comparisons were conducted from 2002 through 2005. The rye cover crop treatment significantly reduced subsurface drainage water flow-weighted NO3 concentrations and NO3 loads in all 4 yr. The rye cover crop treatment did not significantly reduce cumulative annual drainage. Averaged over 4 yr, the rye cover crop reduced flow-weighted NO3 concentrations by 59% and loads by 61%. The gamagrass strips did not significantly reduce cumulative drainage, the average annual flow-weighted NO3 concentrations, or cumulative NO3 loads averaged over the 4 yr. Rye winter cover crops grown after corn and soybean have the potential to reduce the NO3 concentrations and loads delivered to surface waters by subsurface drainage systems.

  8. Estimation of agricultural pesticide use in drainage basins using land cover maps and county pesticide data

    Nakagaki, Naomi; Wolock, David M.


    A geographic information system (GIS) was used to estimate agricultural pesticide use in the drainage basins of streams that are studied as part of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. Drainage basin pesticide use estimates were computed by intersecting digital maps of drainage basin boundaries with an enhanced version of the National Land Cover Data 1992 combined with estimates of 1992 agricultural pesticide use in each United States county. This report presents the methods used to quantify agricultural pesticide use in drainage basins using a GIS and includes the estimates of atrazine use applied to row crops, small-grain crops, and fallow lands in 150 watersheds in the conterminous United States. Basin atrazine use estimates are presented to compare and analyze the results that were derived from 30-meter and 1-kilometer resolution land cover and county pesticide use data, and drainage basin boundaries at various grid cell resolutions. Comparisons of the basin atrazine use estimates derived from watershed boundaries, county pesticide use, and land cover data sets at different resolutions, indicated that overall differences were minor. The largest potential for differences in basin pesticide use estimates between those derived from the 30-meter and 1-kilometer resolution enhanced National Land Cover Data 1992 exists wherever there are abrupt agricultural land cover changes along the basin divide. Despite the limitations of the drainage basin pesticide use data described in this report, the basin estimates provide consistent and comparable indicators of agricultural pesticide application in surface-water drainage basins studied in the NAWQA Program.

  9. Productivity of Stream Definitions

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


    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

  10. Productivity of stream definitions

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


    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 prod

  11. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts

    Saftoiu, Adrian; Vilmann, Andreas; Vilmann, Peter


    Pancreatic pseudocysts are fluid collections in the peripancreatic tissues associated with acute or chronic pancreatitis. Endoscopic ultrasound (EUS)-guided drainage has become an established indication, having better results as compared to percutaneous drainage, nonguided endoscopic drainage...

  12. Drainage basin and topographic analysis of a tropical landscape: Insights into surface and tectonic processes in northern Borneo

    Mathew, Manoj Joseph; Menier, David; Siddiqui, Numair; Ramkumar, Mu.; Santosh, M.; Kumar, Shashi; Hassaan, Muhammad


    We investigated the recent landscape development of Borneo through geomorphic analysis of two large drainage basins (Rajang and Baram basins). The extraction of morphometric parameters utilizing digital terrain data in a GIS environment, focusing on hydrography (stream length-gradient index, ratio of valley floor width to valley height, and transverse topographic symmetry factor) and topography (local relief and relief anomaly), was carried out in order to elucidate processes governing drainage and landscape evolution. Anomalously high and low values of stream length-gradient indices of main tributary streams associated with faults and multiple knick-points along the channel profiles are linked to deformation events. The development of deeply incised V-shaped valleys show enhanced incision capability of streams in response to steepening of hillslope gradients following tectonic inputs. Deflection of streams and probable dynamic reorganization of the drainage system through stream capture processes as feedbacks to tectonic uplift and orographic effect are observed. Local relief and relief anomaly maps highlight the presence of preserved elevation-accordant relict portions of landscapes characterized by low amplitude relief, nested between ridgelines in regions of complex folding. Our results reveal dynamic geomorphic adjustment of the landscape due to perturbations in tectonic and climatic boundary conditions. The implication is that the landscape of north Borneo experienced a tectonic phase of rapid uplift after 5 Ma and undergoes active folding of the Rajang Group thrust belts in the present-day. Active shortening combined with high rates of denudation in Sarawak, demonstrates transience emphasized by the drainage system attempting to adjust to tectonic and climatic forcing.

  13. Effects of Riverbed Conductance on Stream Depletion

    Lackey, G.; Neupauer, R. M.; Pitlick, J.


    In the western United States and other regions of the world where growing population and changing climates are threatening water supplies, accurate modeling of potential human impacts on water resources is becoming more important. Stream depletion, the reduction of surface water flow due to the extraction of groundwater from a hydraulically connected aquifer, is one of the more direct ways that development can alter water availability, degrade water quality and endanger aquatic habitats. These factors have made the accurate modeling of stream depletion an important step in the process of installing groundwater wells in regions that are susceptible to this phenomenon. Proper estimation of stream depletion requires appropriate parameterization of aquifer and streambed hydraulic properties. Although many studies have conducted numerical investigations to determine stream depletion at specific sites, they typically do not measure streambed hydraulic conductivity (Kr), but rather assume a representative value. In this work, we establish a hypothetical model aquifer that is 2000 m by 1600 m and has a meandering stream running through its center. The Kr of the model stream is varied from 1.0x10-9 m s-1 to 1.0x10-2 m s-1 in order to determine the sensitivity of the stream depletion calculations to this parameter. It was found that when Kr is in the lower part of this range, slight changes in K¬r lead to significant impacts on the calculated stream depletion values. We vary Kr along the stream channel according to naturally occurring patterns and demonstrate that alterations of the parameter over a few orders of magnitude can affect the estimated stream depletion caused by a well at a specified location. The numerical simulations show that the mean value of Kr and its spatial variability along the channel should be realistic to develop an accurate model of stream depletion.

  14. Iron photoreduction and oxidation in an acidic mountain stream.

    McKnight, D M; Kimball, B A; Bencala, K E


    In a small mountain stream in Colorado that receives acidic mine drainage, photoreduction of ferric iron results in a well-defined increase in dissolved ferrous iron during the day. To quantify this process, an instream injection of a conservative tracer was used to measure discharge at the time that each sample was collected. Daytime production of ferrous iron by photoreduction was almost four times as great as nighttime oxidation of ferrous iron. The photoreduction process probably involves dissolved or colloidal ferric iron species and limited interaction with organic species because concentrations of organic carbon are low in this stream.

  15. The role of antecedent drainage networks and isolated normal fault propagation on basin stratigraphy

    Finch, E.; Brocklehurst, S. H.; Gawthorpe, R.


    The stratigraphy of an extensional basin reflects a history of fault activity, erosion, drainage network evolution, and sediment transport and deposition. Here a three-dimensional numerical model of erosion and clastic sedimentation is applied to investigate the effect of displacement on a normal fault to the distribution of deposition in an extensional basin. Material is eroded from the hinterland through a stream-power incision law and deposited in the basin using a modified diffusion algorithm. Experiments are implemented for 3Ma, in which the initial 1Ma are used to permit a drainage network to evolve to a topographic steady state. This system is then perturbed by the introduction of a propagating isolated normal fault at varying displacement rates (1.0m/kyr - 2.0m/kyr) to demonstrate the influence of fault propagation on drainage capture, network re-organisation, sediment routing and deposition. Faster displacement rates and smaller antecedent drainage networks cause footwall-derived deltas to be cut-off more rapidly from the hinterland source area. Drainage networks are re-organised such that sediment is then transported around the fault tips into axially sourced deltas. Sediments may continue to be deposited in the hanging wall at the fault centre, but this material has not been sourced directly from the adjacent footwall, even though the stratigraphic architecture might suggest that this is the case. Drainage networks are modified by drainage reversals in the antecedent channels, and the development of areas of abandoned/trapped drainage. These changes in sediment supply due to network re-organisation are also reflected in the basin stratigraphy, with rapid back-stepping of deltas when the source is removed in the adjacent footwall. Later incision and headward erosion of the footwall channels may cause re-capture of earlier channels, while network re-organisation may also cause depositional in-filling of earlier channels. The drainage divide shifts

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

    Rasmussen, Jes

    was calculated for 1 km2 catchments (produced from topographical maps) on Funen, Denmark. The physical condition (substrate, meandering etc.) of 1st and 2nd order streams (based on existing data from the National Monitoring Programme and personal exploring) draining these catchments was, additionally, assessed...... 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...

  17. Persistent Temporal Streams

    Hilley, David; Ramachandran, Umakishore

    Distributed continuous live stream analysis applications are increasingly common. Video-based surveillance, emergency response, disaster recovery, and critical infrastructure protection are all examples of such applications. They are characterized by a variety of high- and low-bandwidth streams as well as a need for analyzing both live and archived streams. We present a system called Persistent Temporal Streams (PTS) that supports a higher-level, domain-targeted programming abstraction for such applications. PTS provides a simple but expressive stream abstraction encompassing transport, manipulation and storage of streaming data. In this paper, we present a system architecture for implementing PTS. We provide an experimental evaluation which shows the system-level primitives can be implemented in a lightweight and high-performance manner, and an application-based evaluation designed to show that a representative high-bandwidth stream analysis application can be implemented relatively simply and with good performance.

  18. Eucalypt plantations reduce the diversity of macroinvertebrates in small forested streams

    Cordero–Rivera, A.


    Full Text Available Land use patterns of a river basin have a significant effect on the structure and function of river ecosystems. Changes in the composition of riparian plant communities modify the quantity, quality and seasonality of leaf–litter inputs, determining changes in macroinvertebrate colonization and activity. The main goal of this study was to test the effect of land–use modifications, and particularly the impact of eucalypt plantations, on the macroinvertebrate communities of sixteen headwater streams. Macroinvertebrates were counted and identified to family level. Land uses were classified in five categories using aerial photography: native forest, eucalypt plantations, agricultural land, shrubland, and urban areas. We found that macroinvertebrate diversity increased with basin size and with the proportion of basin covered by native forest. This variable correlated negatively with the land occupied by eucalypt plantations. Macroinvertebrate richness diminished with the increase of land surface covered by eucalypt plantations, and a similar tendency was observed with diversity. Furthermore, streams whose drainage basin was mainly covered by Eucalyptus were more likely to dry up in summer. This observation adds to evidence from previous studies that concluded that fast–growing tree plantations affect hydric resources, an important ecosystem service in the context of global warming. To minimize the impact of industrial sylviculture, we suggest that maintaining and/or restoring riparian forests could mitigate the effects of intensive eucalypt monocultures.

  19. Gravity Drainage Kinetics of Papermaking Fibrous Suspensions

    Przybysz Piotr


    Full Text Available The study analyses application possibilities of filtration and thickening models in evaluation of papermaking suspension drainage rate. The authors proposed their own method to estimate the drainage rate on the basis of an existing Ergun capillary model of liquid flow through a granular material. The proposed model was less sensitive to porosity changes than the Ergun model. An empirical verification proved robustness of the proposed approach. Taking into account discrepancies in the published data concerning how the drainage velocity of papermaking suspension is defined, this study examines which of the commonly applied models matches experimental results the best.

  20. The many streams of the Magellanic Stream

    Stanimirovic, Snezana; Heiles, Carl; Douglas, Kevin A; Putman, Mary; Peek, Joshua E G


    We present results from neutral hydrogen (HI) observations of the tip of the Magellanic Stream (MS), obtained with the Arecibo telescope as a part of the on-going survey by the Consortium for Galactic studies with the Arecibo L-band Feed Array. We find four large-scale, coherent HI streams, extending continously over a length of 20 degrees, each stream possessing different morphology and velocity gradients. The newly discovered streams provide strong support for the tidal model of the MS formation by Connors et al. (2006), which suggested a spatial and kinematic bifurcation of the MS. The observed morphology and kinematics suggest that three of these streams could be interpreted as a 3-way splitting of the main MS filament, while the fourth stream appears much younger and may have originated from the Magellanic Bridge. We find an extensive population of HI clouds at the tip of the MS. Two thirds of clouds have an angular size in the range 3.5'--10'. We interpret this as being due to thermal instability, which...

  1. A subglacial hydrological analysis of Recovery Ice Stream using GlaDS

    Dow, Christine; Werder, Mauro; Nowicki, Sophie; Walker, Ryan; Babonis, Greg; Csatho, Bea; Morlighem, Mathieu


    We use GlaDS, a 2D subglacial hydrology model, to assess subglacial drainage development in Recovery Ice Stream. Our primary aims are to a) examine the characteristics of subglacial lake growth and drainage, and b) investigate the impact of the drainage events on the dynamics of the ice stream. We first apply GlaDS to a synthetic system with one overdeepened region. The model outputs suggest that the highly constricted environment of the ice stream combined with funneling of relatively high rates of subglacial water flow from the large catchment, combine to create slow-moving high-pressure waves. The waves cause temporally varying water flow rates through the hydrological system that drives lake growth. As water builds up in the overdeepening, the hydraulic potential gradient steepens and allows greater flux out of the lake basin. Over time, this flux causes channel growth that triggers lake drainage after several years. Following lake drainage, channels again shut down. Due to the channels, high water pressures associated with lake drainage are apparent 50 km downstream of the lake rather than immediately in the vicinity of the overdeepening. We investigate the system further by applying the hydrology model using the basal and surface topography of Recovery Ice Stream extrapolated from BEDMAP2 and mass conservation techniques. Preliminary results suggest that the subglacial water volumes and depths accumulated in the lakes are similar to those estimated through satellite-altimetry based techniques. We discuss primary water flow routes and compare the modelled lake drainage timing with ICESat surface altimetry records.

  2. Drainage filter technologies to mitigate site-specific phosphorus losses in agricultural drainage discharge

    Kjærgaard, Charlotte; Heckrath, Goswin Johann; Canga, Eriona;

    Losses of phosphorus (P) in drainage waters contribute an estimated 33% to the total agricultural P load in Denmark. Mitigating agricultural P losses is challenging, as critical P losses comprise only a very small fraction of actual soil P contents and are not directly related to fertilizer P input...... in drainage. The Danish “SUPREME-TECH” project (2010-2016) ( aims at providing the scientific basis for developing cost-effective filter technologies for P in agricultural drainage waters. The project studies different approaches of implementing filter technologies including drainage well...... the occurrence of surface-induced precipitation processes. The P-retention efficiency of granular drainage filters and constructed wetlands was compared for treating drainage water, and a subcatchment analysis illustrated the potential of implementing such measures....

  3. Impacts of Woody Debris on Fluvial Processes and Channel Morphology in Stable and Unstable Streams


    and requires approximately 98 mb of memory to install. 0 The GIS is composed of four layers: the drainage network; road network; landcover ; and...Froehlich H. A. (1988), "Woody debris and its contribution to pool formation in a coastal stream 50 years after logging", Canadian Journal of Aquatic...and temporal evolution of small coastal gravel-bed streams: The influence of forest management on channel morphology and fish habitats", paper prepared

  4. Directional sensing and streaming in Dictyostelium aggregation.

    Almeida, Sofia; Dilão, Rui


    We merge the Kessler-Levine simple discrete model for Dictyostelium cyclic adenosine monophosphate (cAMP) production and diffusion with the Dilão-Hauser directional sensing aggregation mechanism. The resulting compound model describes all the known transient patterns that emerge during Dictyostelium aggregation, which include the spontaneous formation of cAMP self-sustained target and spiral waves and streaming. We show that the streaming patterns depend on the speed of the amoebae, on the relaxation time for the production of cAMP, on the cAMP degradation rate, and on directional sensing. Moreover, we show that different signaling centers emerge during Dictyostelium aggregation.

  5. Fractal Analysis of Drainage Basins on Mars

    Stepinski, T. F.; Marinova, M. M.; McGovern, P. J.; Clifford, S. M.


    We used statistical properties of drainage networks on Mars as a measure of martian landscape morphology and an indicator of landscape evolution processes. We utilize the Mars Orbiter Laser Altimeter (MOLA) data to construct digital elevation maps (DEMs) of several, mostly ancient, martian terrains. Drainage basins and channel networks are computationally extracted from DEMs and their structures are analyzed and compared to drainage networks extracted from terrestrial and lunar DEMs. We show that martian networks are self-affine statistical fractals with planar properties similar to terrestrial networks, but vertical properties similar to lunar networks. The uniformity of martian drainage density is between those for terrestrial and lunar landscapes. Our results are consistent with the roughening of ancient martian terrains by combination of rainfall-fed erosion and impacts, although roughening by other fluvial processes cannot be excluded. The notion of sustained rainfall in recent Mars history is inconsistent with our findings.

  6. Results of percutaneous transhepatic cholangiography drainages (PTCD)

    Schoenemann, J.; Willems, M.; Wolf, G.; Fromme, M.


    From September 1980 to December 1986, 72 percutaneous transhepatic cholangiography drainages (PTCD) were performed in 64 patients (58 palliative in malignant obstructions, 14 temporary). The median duration of drainage was 26.8 days (2-183 days). The median survival time in 37 patients with palliative tumour drainage was 55.3 days (7-473 days). 9/37 patients survived longer than 3 months (max. 15.5 months). Complications occurred in 29.5% (10.3% severe). 3/64 patients (4.7%) died. Patients with palliative transpapillary drainages (23), especially with endoprostheses (14), survived longer, and the complication rate was lower. Therefore, we prefer the endoscopic transpapillary approach. PTCD patients must be selected carefully.

  7. Fractal Analysis of Drainage Basins on Mars

    Stepinski, T. F.; Marinova, M. M.; McGovern, P. J.; Clifford, S. M.


    We used statistical properties of drainage networks on Mars as a measure of martian landscape morphology and an indicator of landscape evolution processes. We utilize the Mars Orbiter Laser Altimeter (MOLA) data to construct digital elevation maps (DEMs) of several, mostly ancient, martian terrains. Drainage basins and channel networks are computationally extracted from DEMs and their structures are analyzed and compared to drainage networks extracted from terrestrial and lunar DEMs. We show that martian networks are self-affine statistical fractals with planar properties similar to terrestrial networks, but vertical properties similar to lunar networks. The uniformity of martian drainage density is between those for terrestrial and lunar landscapes. Our results are consistent with the roughening of ancient martian terrains by combination of rainfall-fed erosion and impacts, although roughening by other fluvial processes cannot be excluded. The notion of sustained rainfall in recent Mars history is inconsistent with our findings.

  8. The Puzzling Ophiuchus Stream

    Kohler, Susanna


    Dwarf galaxies or globular clusters orbiting the Milky Way can be pulled apart by tidal forces, leaving behind a trail of stars known as a stellar stream. One such trail, the Ophiuchus stream, has posed a serious dynamical puzzle since its discovery. But a recent study has identified four stars that might help resolve this streams mystery.Conflicting TimescalesThe stellar stream Ophiuchus was discovered around our galaxy in 2014. Based on its length, which appears to be 1.6 kpc, we can calculate the time that has passed since its progenitor was disrupted and the stream was created: ~250 Myr. But the stars within it are ~12 Gyr old, and the stream orbits the galaxy with a period of ~350 Myr.Given these numbers, we can assume that Ophiuchuss progenitor completed many orbits of the Milky Way in its lifetime. So why would it only have been disrupted 250 million years ago?Fanning StreamLed by Branimir Sesar (Max Planck Institute for Astronomy), a team of scientists has proposed an idea that might help solve this puzzle. If the Ophiuchus stellar stream is on a chaotic orbit common in triaxial potentials, which the Milky Ways may be then the stream ends can fan out, with stars spreading in position and velocity.The fanned part of the stream, however, would be difficult to detect because of its low surface brightness. As a result, the Ophiuchus stellar stream could actually be longer than originally measured, implying that it was disrupted longer ago than was believed.Search for Fan StarsTo test this idea, Sesar and collaborators performed a search around the ends of the stream, looking for stars thatare of the right type to match the stream,are at the predicted distance of the stream,are located near the stream ends, andhave velocities that match the stream and dont match the background halo stars.Histogram of the heliocentric velocities of the 43 target stars. Six stars have velocities matching the stream velocity. Two of these are located in the main stream; the other

  9. Guidelines for Surveying Bankfull Channel Geometry and Developing Regional Hydraulic-Geometry Relations for Streams of New York State

    Powell, Rocky O.; Miller, Sarah J.; Westergard, Britt E.; Mulvihill, Christiane I.; Baldigo, Barry P.; Gallagher, Anne S.; Starr, Richard R.


    Many disturbed streams within New York State are being restored in an effort to provide bank and bed stability and thereby decrease sedimentation and erosion. Efforts to identify and provide accurate indicators for stable-channel characteristics for ungaged streams have been hampered by the lack of regional equations or relations that relate drainage area to bankfull discharge and to channel depth, width, and cross-sectional area (bankfull hydraulic-geometry relations). Regional equations are needed to confirm bankfull hydraulic-geometry, assess stream stability, evaluate restoration needs, and verify restoration design for ungaged streams that lack stage-to-discharge ratings or historic peak-flow records. This report presents guidelines for surveying bankfull channel geometry at USGS stream gages and developing regional hydraulic-geometry relations (equations) for wadeable streams in New York. It summarizes methods to (1) compile and assess existing hydrologic, geometric, photographic, and topographic data, (2) conduct stream-reconnaissance inspections, (3) identify channel-bankfull characteristics, (4) conduct longitudinal and cross-section surveys, (5) measure stream discharge, (6) develop and refine bankfull hydraulic-geometry equations, and (7) analyze and assure data completeness and quality. The techniques primarily address wadeable streams with either active or discontinued surface-water and crest-stage gages. The relations can be applied to ungaged or actively gaged streams that are wadeable, and may be extended to non-wadeable streams (with some limitations) if they have drainage areas comparable to those used to develop the relations.

  10. A stream-gaging network analysis for the 7-Day, 10-year annual low flow in New Hampshire streams

    Flynn, Robert H.


    The 7-day, 10-year (7Q10) low-flow-frequency statistic is a widely used measure of surface-water availability in New Hampshire. Regression equations and basin-characteristic digital data sets were developed to help water-resource managers determine surface-water resources during periods of low flow in New Hampshire streams. These regression equations and data sets were developed to estimate streamflow statistics for the annual and seasonal low-flow-frequency, and period-of-record and seasonal period-of-record flow durations. generalized-least-squares (GLS) regression methods were used to develop the annual 7Q10 low-flow-frequency regression equation from 60 continuous-record stream-gaging stations in New Hampshire and in neighboring States. In the regression equation, the dependent variables were the annual 7Q10 flows at the 60 stream-gaging stations. The independent (or predictor) variables were objectively selected characteristics of the drainage basins that contribute flow to those stations. In contrast to ordinary-least-squares (OLS) regression analysis, GLS-developed estimating equations account for differences in length of record and spatial correlations among the flow-frequency statistics at the various stations. A total of 93 measurable drainage-basin characteristics were candidate independent variables. On the basis of several statistical parameters that were used to evaluate which combination of basin characteristics contribute the most to the predictive power of the equations, three drainage-basin characteristics were determined to be statistically significant predictors of the annual 7Q10: (1) total drainage area, (2) mean summer stream-gaging station precipitation from 1961 to 90, and (3) average mean annual basinwide temperature from 1961 to 1990. To evaluate the effectiveness of the stream-gaging network in providing regional streamflow data for the annual 7Q10, the computer program GLSNET (generalized-least-squares NETwork) was used to analyze the

  11. Decoding the role of tectonics, incision and lithology on drainage divide migration in the Mt. Alpi region, southern Apennines, Italy

    Buscher, J. T.; Ascione, A.; Valente, E.


    The proclivity of river networks to progressively carve mountain surfaces and preserve markers of landscape adjustments has made analyses of fluvial systems fundamental for understanding the topographic development of orogens. However, the transient nature of uplift and erosion has posed a challenge for inferring the roles that tectonics and/or climate have played on generating topographic relief. The Mt. Alpi region in the southern Apennines has a heterogeneous distribution of elevated topography, erosionally-resistant lithology and uplift, making the area optimal for conducting topographic and river analyses to better understand the landscape development of a transient orogen. Stream length-gradient, normalized channel steepness, stream convexity and first-order channel gradient indices from 10 m digital elevation data from the region exhibit stream profile inconsistencies along the current drainage divide and a dominance of high values subparallel but inboard of the primary chain axis irrespective of known transient landscape factors, suggesting that the current river network may be in a state of transition. The location of these stream profile anomalies both near the modern drainage divide and subparallel to an isolated swath of high topography away from catchment boundaries is thought to be the topographic expression of an imminent drainage divide migration driven primarily by the northeast-vergent extension of the western chain axis.

  12. Groundwater Discharge along a Channelized Coastal Plain Stream

    LaSage, Danita M [Ky Dept for natural resources, Div of Mine Permits; Sexton, Joshua L [JL Sexton and Son; Mukherjee, Abhijit [Univ of Tx, Jackson School of Geosciences, Bur of Econ. Geology; Fryar, Alan E [Univ of KY, Dept of Earth and Geoligical Sciences; Greb, Stephen F [Univ of KY, KY Geological Survey


    In the Coastal Plain of the southeastern USA, streams have commonly been artificially channelized for flood control and agricultural drainage. However, groundwater discharge along such streams has received relatively little attention. Using a combination of stream- and spring-flow measurements, spring temperature measurements, temperature profiling along the stream-bed, and geologic mapping, we delineated zones of diffuse and focused discharge along Little Bayou Creek, a channelized, first-order perennial stream in western Kentucky. Seasonal variability in groundwater discharge mimics hydraulic-head fluctuations in a nearby monitoring well and spring-discharge fluctuations elsewhere in the region, and is likely to reflect seasonal variability in recharge. Diffuse discharge occurs where the stream is incised into the semi-confined regional gravel aquifer, which is comprised of the Mounds Gravel. Focused discharge occurs upstream where the channel appears to have intersected preferential pathways within the confining unit. Seasonal fluctuations in discharge from individual springs are repressed where piping results in bank collapse. Thereby, focused discharge can contribute to the morphological evolution of the stream channel.

  13. Drainage, sediment transport, and denudation rates on the Nanga Parbat Himalaya, Pakistan

    Cornwell, Kevin; Norsby, Doug; Marston, Richard


    The Nanga Parbat Himalaya presents some of the greatest relief on Earth, yet sediment production and denudation rates have only been sporadically addressed. We utilized field measurements and computer models to estimate bank full discharge, sediment transport, and denudation rates for the Raikot and Buldar drainage basins (north slope of Nanga Parbat) and the upper reach of the Rupal drainage basin (south slope). The overall tasks of determining stream flow conditions in such a dynamic geomorphic setting is challenging. No gage data exist for these drainage basins, and the overall character of the drainage basins (high relief, steep flow gradients, and turbulent flow conditions) does not lend itself to either ready access or complete profiling. Cross-sectional profiles were surveyed through selected reaches of these drainage basins. These data were then incorporated into software (WinXSPRO) that aids in the characterization (stage, discharge, velocity, and shear stress) of high altitude, steep mountain stream conditions. Complete field measurements of channel depths were rarely possible (except at several bridges where the middle of the channel could actually be straddled and probed) and, when coupled with velocity measurements, provided discrete points of field-measured discharge calculations. These points were then used to calibrate WinXSPRO results for the same reach and provided a confidence level for computer-generated results. Flow calculations suggest that under near bank full conditions, the upper Raikot drainage basin produces discharges of ˜61 cm and moves about 11,000 tons day -1 (9980 tons day -1) of sediment through its channel. Bank full conditions on the upper portion of the Rupal drainage basin generate discharges of ˜84 cm and moves only about 3800 tons day -1 (3450 tons day -1) of sediment. Although the upper Rupal drainage basin moves more water, the lower slope of the drainage basin (0.03) generates a much smaller shear stress (461 Pa) than


    GRAY, NICHOLAS FREDERICK; Sullivan, Monica


    This review examine the action of acid mine drainage (AMD), which is a multifactor pollutant, on surface waters. It affects aquatic ecosystems via a number of direct and indirect pathways. Major impact areas are coastal waters, rivers, lakes and estuaries, with AMD affecting ecosystems in different ways. Ground waters can also be severely impacted. Due to its complexity, the impact of AMD is particularly difficult to quantify and predict in lotic systems. Acid mine drainage pollut...

  15. Percutaneous drainage of pelvic fluid collection

    Lee, Eun Young; Sohn, Cheol Ho [School of Medicine Keimyung University, Daegu (Korea, Republic of)


    To evaluate safe access route and success rate of percutaneous drainage of pelvic fluid collection. The 35 percutaneous drainages of pelvic fluid collection under the CT and fluorosocpic guidance were done in 32 patients. The anterior transabdominal approach was done in 20 patients, while the nine patients used the transgluteal approach through greater sciatic foramen. Three patients, who had septated or noncommunicating abscesses, underwent drainage using both approaches. The catheter was removed when the patient's symptom and laboratory data were improved or the amount of drainage and the size of fluid collection were markedly reduced. Success, partial success and failure were classified. The causes of fluid collection were complication of intraabdominal operation in 27 patient. The diagnosis after drainage included abscess (21), loculated ascites (6), and hematoma (4). The 27 cases (30 procedure) were treated successfully and the mean duration of catheter insertion was 10 days. The partial successes were two cases (2 procedures), which had palliative purpose. Three cases (3 procedures) were failed, which were multiple loculated ascites of pancreatic origin (2) and recurrent abscess (1). The significant complication during the procedure or drainage was not noted.

  16. The formation of viscous limited saturation zones behind rapid drainage fronts in porous media

    Hoogland, Frouke; Lehmann, Peter; Or, Dani


    Drainage characteristics of porous media are shaped by an interplay between gravitational, capillary and viscous forces that result in complex phase invasion patterns and dynamics. We propose a mechanistic model for viscous separation of temporary phase detention behind rapidly moving drainage fronts. The viscous-limited region forming behind the front tip (tip of furthest penetrated air finger) drains at a slower rate with a characteristic time scale τ dictated by hydraulic decoupling expressed by the hydraulic properties of the medium. The region where saturation becomes viscously detained (temporarily entrapped) is determined by a critical water content θcrit that defines a viscous length LV behind the front tip. Theory developed to predict the critical water content θcrit and the characteristic secondary timescale τ was in good agreement with measured drainage characteristics using neutron radiography and direct imaging. The observed critical water content θcrit increased with higher drainage rates as predicted by theory with consideration of a percolation threshold. The observed slow drainage timescale τ as a function of mean drainage rate depended on the critical water content θcrit and the resulting counteracting effects of increased detained liquid volume and increased conductivity of the viscous limited region. The concept of drainage zonation illustrates how increasing flow rates enhances the extent of viscous limitations behind the main drainage front. The new insights could be useful for management of immiscible fluid displacement, quantification of averaging effects in experimental measurements (dynamic effects on pc-S relationship), and explain some of the underpinnings of the field capacity phenomenon.

  17. 46 CFR 171.155 - Drainage of an open boat.


    ... PERTAINING TO VESSELS CARRYING PASSENGERS Drainage of Weather Decks § 171.155 Drainage of an open boat. The deck within the hull of an open boat must drain to the bilge. Overboard drainage of the deck is not... 46 Shipping 7 2010-10-01 2010-10-01 false Drainage of an open boat. 171.155 Section 171.155...

  18. A dynamically reconfigurable data stream processing system

    Nogiec, J.M.; Trombly-Freytag, K.; /Fermilab


    This paper describes a component-based framework for data stream processing that allows for configuration, tailoring, and runtime system reconfiguration. The system's architecture is based on a pipes and filters pattern, where data is passed through routes between components. A network of pipes and filters can be dynamically reconfigured in response to a preplanned sequence of processing steps, operator intervention, or a change in one or more data streams. This framework provides several mechanisms supporting dynamic reconfiguration and can be used to build static data stream processing applications such as monitoring or data acquisition systems, as well as self-adjusting systems that can adapt their processing algorithm, presentation layer, or data persistency layer in response to changes in input data streams.

  19. The Andromeda Stream

    Lewis, G F; Ferguson, A M N; Ibata, R A; Irwin, M J; McConnachie, A W; Tanvir, N


    The existence of a stream of tidally stripped stars from the Sagittarius Dwarf galaxy demonstrates that the Milky Way is still in the process of accreting mass. More recently, an extensive stream of stars has been uncovered in the halo of the Andromeda galaxy (M31), revealing that it too is cannibalizing a small companion. This paper reports the recent observations of this stream, determining it spatial and kinematic properties, and tracing its three-dimensional structure, as well as describing future observations and what we may learn about the Andromeda galaxy from this giant tidal stream.

  20. Hydrography - Streams and Shorelines

    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...

  1. The case against streaming

    Natalia Mironova


    .... 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...

  2. Inventory of miscellaneous streams

    Lueck, K.J.


    On December 23, 1991, the US Department of Energy, Richland Operations Office (RL) and the Washington State Department of Ecology (Ecology) agreed to adhere to the provisions of the Department of Ecology Consent Order. The Consent Order lists the regulatory milestones for liquid effluent streams at the Hanford Site to comply with the permitting requirements of Washington Administrative Code. The RL provided the US Congress a Plan and Schedule to discontinue disposal of contaminated liquid effluent into the soil column on the Hanford Site. The plan and schedule document contained a strategy for the implementation of alternative treatment and disposal systems. This strategy included prioritizing the streams into two phases. The Phase 1 streams were considered to be higher priority than the Phase 2 streams. The actions recommended for the Phase 1 and 2 streams in the two reports were incorporated in the Hanford Federal Facility Agreement and Consent Order. Miscellaneous Streams are those liquid effluents streams identified within the Consent Order that are discharged to the ground but are not categorized as Phase 1 or Phase 2 Streams. This document consists of an inventory of the liquid effluent streams being discharged into the Hanford soil column.

  3. [The value of wound drainage with or without suction].

    Schmidt, J; Hasselbach, A; Schnorr, W; Baranek, T; Letsch, R


    Even though the discussion for desisting from wound drainage has arisen, this is not reflected in the reality of surgical treatment. In more than 90% of all procedures wound drainage is used. It remains to be proven whether suction drainage actually is superior to gravity drainage in everyday use. In a random study with 200 patients it was proven that suction drainage shows no significant advantage in liquid quantum, haematoma and the frequency of complications. We conclude that the economically favourable gravity drainage can replace the more expensive suction drainage in most cases.

  4. Reach Scale Studies of Trace Metal Transport in Mountain Streams: Do Wetlands Act as a Sink or a Source?

    McKnight, D. M.; August, E.; Duren, S.; Wong, J.


    In the Rocky Mountains, there are many watersheds containing streams impacted by acid rock and acid mine drainage. These streams typically have high concentrations of dissolved metals and copious amounts of iron and aluminum oxides deposited on the streambed. Remediation of these contaminated streams is challenging because of the remote locations of the abandoned mines and the large amounts of metal oxides potentially generated in treatment of the drainage. Wetlands have the potential to attenuate trace metal transport. We examined retention of metals in an iron-oxide rich wetland near Leadville, CO, which had been receiving mine drainage for almost a century. We found that in the summer, the wetland did have a net retentive effect for most metals studied, limiting input into the adjacent stream, whereas, the wetland was a net source of metals during the winter. Furthermore, during spring snowmelt, the wetland did not retain the large pulse of zinc and iron leached by melting snow on the surrounding tailings piles. In another stream system receiving acid rock drainage, we found that riparian wetlands become sources of metals to the stream under drought conditions, which further exacerbated the metal enrichment associated with lesser snowmelt dilution.

  5. Failures and complications of thoracic drainage

    Đorđević Ivana


    Full Text Available Background/Aim. Thoracic drainage is a surgical procedure for introducing a drain into the pleural space to drain its contents. Using this method, the pleura is discharged and set to the physiological state which enables the reexpansion of the lungs. The aim of the study was to prove that the use of modern principles and protocols of thoracic drainage significantly reduces the occurrence of failures and complications, rendering the treatment more efficient. Methods. The study included 967 patients treated by thoracic drainage within the period from January 1, 1989 to June 1, 2000. The studied patients were divided into 2 groups: group A of 463 patients treated in the period from January 1, 1989 to December 31, 1994 in whom 386 pleural drainage (83.36% were performed, and group B of 602 patients treated form January 1, 1995 to June 1, 2000 in whom 581 pleural drainage (96.51% were performed. The patients of the group A were drained using the classical standards of thoracic drainage by the general surgeons. The patients of the group B, however, were drained using the modern standards of thoracic drainage by the thoracic surgeons, and the general surgeons trained for this kind of the surgery. Results. The study showed that better results were achieved in the treatment of the patients from the group B. The total incidence of the failures and complications of thoracic drainage decreased from 36.52% (group A to 12.73% (group B. The mean length of hospitalization of the patients without complications in the group A was 19.5 days versus 10 days in the group B. The mean length of the treatment of the patients with failures and complications of the drainage in the group A was 33.5 days versus 17.5 days in the group B. Conclusion. The shorter length of hospitalization and the lower morbidity of the studied patients were considered to be the result of the correct treatment using modern principles of thoracic drainage, a suitable surgical technique, and a

  6. Developmental venous anomalies of the posterior fossa with transpontine drainage: report of 3 cases

    Kueker, W. [Department of Neuroradiology, Technical University, Pauwelsstrasse 30, D-52 057 Aachen (Germany); Mull, M. [Department of Neuroradiology, Technical University, Pauwelsstrasse 30, D-52 057 Aachen (Germany); Thron, A. [Department of Neuroradiology, Technical University, Pauwelsstrasse 30, D-52 057 Aachen (Germany)


    Developmental venous anomalies (DVA) are considered as variant patterns of cerebral venous drainage. Although generally not rare in the cerebellum, DVA of the brain stem or of the cerebellum with drainage through the brain stem are exceptional findings. Because it is not clear whether DVA may sometimes be of clinical significance, we try to correlate the clinical findings of the patients with the course of the variant vessels. We reviewed the literature and report three additional cases. All patients were examined by MRI and digital subtraction angiography. In particular, we discuss the drainage route as compared with the established patterns of posterior fossa blood drainage, which is directed to the dural sinuses, the petrosal vein or the vein of Galen. In one of our patients suffering from trigeminal neuralgia, the close topical relation of the DVA and the trigeminal nucleus and trigeminal nerve entry zone suggests a causal relationship. In a second case the brain stem symptoms were due to haemorrhage of a concomitant cavernoma. It remains unclear if the occurrence of dysarthria and dysaesthesia in the third patient with brain stem DVA was purely coincidental. The only clinical symptom directly attributable to a DVA with transpontine drainage in our series was trigeminal neuralgia. (orig.). With 3 figs., 1 tab.

  7. Ecological assessment of streams in the Powder River Structural Basin, Wyoming and Montana, 2005-06

    Peterson, D.A.; Wright, P.R.; Edwards, G.P.; Hargett, E.G.; Feldman, D.L.; Zumberge, J.R.; Dey, Paul


    Energy and mineral development, particularly coalbed natural gas development, is proceeding at a rapid pace in the Powder River Structural Basin (PRB) in northeastern Wyoming. Concerns about the potential effects of development led to formation of an interagency working group of primarily Federal and State agencies to address these issues in the PRB in Wyoming and in Montana where similar types of resources exist but are largely undeveloped. Under the direction of the interagency working group, an ecological assessment of streams in the PRB was initiated to determine the current status (2005–06) and to establish a baseline for future monitoring.The ecological assessment components include assessment of stream habitat and riparian zones as well as assessments of macroinvertebrate, algal, and fish communities. All of the components were sampled at 47 sites in the PRB during 2005. A reduced set of components, consisting primarily of macroinvertebrate and fish community assessments, was sampled in 2006. Related ecological data, such as habitat and fish community data collected from selected sites in 2004, also are included in this report.The stream habitat assessment included measurement of channel features, substrate size and embeddedness, riparian vegetation, and reachwide characteristics. The width-to-depth ratio (bankfull width/bankfull depth) tended to be higher at sites on the main-stem Powder River than at sites on the main-stem Tongue River and at sites on tributary streams. The streambed substrate particle size was largest at sites on the main-stem Tongue River and smallest at sites on small tributary streams such as Squirrel Creek and Otter Creek. Total vegetative cover at the ground level, understory, and canopy layers ranged from less than 40 percent at a few sites to more than 90 percent at many of the sites. A bank-stability index indicated that sites in the Tongue River drainage were less at risk of bank failure than sites on the main-stem Powder River

  8. Global 30m Height Above the Nearest Drainage

    Donchyts, Gennadii; Winsemius, Hessel; Schellekens, Jaap; Erickson, Tyler; Gao, Hongkai; Savenije, Hubert; van de Giesen, Nick


    Variability of the Earth surface is the primary characteristics affecting the flow of surface and subsurface water. Digital elevation models, usually represented as height maps above some well-defined vertical datum, are used a lot to compute hydrologic parameters such as local flow directions, drainage area, drainage network pattern, and many others. Usually, it requires a significant effort to derive these parameters at a global scale. One hydrological characteristic introduced in the last decade is Height Above the Nearest Drainage (HAND): a digital elevation model normalized using nearest drainage. This parameter has been shown to be useful for many hydrological and more general purpose applications, such as landscape hazard mapping, landform classification, remote sensing and rainfall-runoff modeling. One of the essential characteristics of HAND is its ability to capture heterogeneities in local environments, difficult to measure or model otherwise. While many applications of HAND were published in the academic literature, no studies analyze its variability on a global scale, especially, using higher resolution DEMs, such as the new, one arc-second (approximately 30m) resolution version of SRTM. In this work, we will present the first global version of HAND computed using a mosaic of two DEMS: 30m SRTM and Viewfinderpanorama DEM (90m). The lower resolution DEM was used to cover latitudes above 60 degrees north and below 56 degrees south where SRTM is not available. We compute HAND using the unmodified version of the input DEMs to ensure consistency with the original elevation model. We have parallelized processing by generating a homogenized, equal-area version of HydroBASINS catchments. The resulting catchment boundaries were used to perform processing using 30m resolution DEM. To compute HAND, a new version of D8 local drainage directions as well as flow accumulation were calculated. The latter was used to estimate river head by incorporating fixed and

  9. Microbiological and chemical characteristics of an acidic stream draining a disused copper mine.

    Walton, K C; Johnson, D B


    Water samples draining a disused copper mine (Parys Mountain) in Anglesey, North Wales, were analysed for distribution of acidophilic bacteria (iron oxidising and heterotrophic) and for changes in physicochemical composition along the length of the drainage stream. Ten samples were taken at regular distance intervals along a 1 km stretch from the source of the acid mine drainage. The stream remained highly acidic (pH iron was in the ferrous form in the upper reaches of the stream, but ferric iron became increasingly dominant downstream as a result of microbial oxidation. Although concentrations of nutrients such as nitrogen and phosphorus were low in the acid mine drainage, they were not limiting rates of bacterial iron oxidation, which appeared to be limited more by temperature. The iron oxidising bacteria Thiobacillus ferrooxidans and Leptospirillum ferrooxidans were both isolated from all sampling sites, although their relative abundances varied; L. ferrooxidans accounted for 57% of all iron oxidising isolates. Numbers of iron oxidising bacteria decreased with distance from drainage source, in contrast to those of acidophilic heterotrophic bacteria which increased. The diversity of heterotrophic isolates also increased with distance. The relationship between the chemistry and microbiology of the stream is discussed.

  10. Detection of hepatitis E virus and other livestock-related pathogens in Iowa streams

    Manure application is a major source of pathogens to the environment. Through overland runoff and tile drainage, these pathogens contaminate surface water and stream bed sediment. Some of these pathogens are zoonotic that can potentially affect both animal and human health. This study examined the p...

  11. Influence of instream habitat and water quality on aggressive behavior in crayfish of channelized headwater streams

    Many agricultural drainage ditches that border farm fields of the Midwestern United States are degraded headwater streams that possess communities of crayfish. We hypothesized that crayfish communities at sites with low instream habitat diversity and poor water quality would show greater evidence of...

  12. The Effect of Restored and Native Oxbows on Hydraulic Loads of Nutrients and Stream Water Quality

    The use of oxbow wetlands has been identified as a potential strategy to reduce nutrient transport from agricultural drainage tiles to streams in Iowa. In 2013 and 2014, a study was conducted in north central Iowa in a native oxbow in the Lyons Creek watershed and two reconstruc...

  13. Data Stream Clustering With Affinity Propagation

    Zhang, Xiangliang


    Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.

  14. Biology of the caddisfly oligostomis ocelligera (Trichoptera: Phryganeidae) inhabiting acidic mine drainage in Pennsylvania

    Redell, L.A.; Gall, W.K.; Ross, R.M.; Dropkin, D.S.


    Oligostomis ocelligera (a phryganeid caddisfly) is reported for the first time from a degraded lotic systema first-order stream in north-central Pennsylvania that was severely impacted by acid mine drainage. Although uncommonly collected and poorly known, O. ocelligera maintained a substantial population in the mine discharge, free of competition from Plecoptera, Ephemeroptera, and other species of Trichoptera. It thrived under conditions of very low pH (2.583.13), high concentrations of sulfate (542 mg/L) and heavy metals (Fe 12 mg/L, Mn 14 mg/L, Al 16 mg/L), and a nearly uniform springbrook-like temperature regime. More than 350 larvae were collected from deposits of leaves and woody detritus in a pool 0.32 km downstream from the mine entrance over a two-year period. Measurement of head-capsule widths yielded a multimodal distribution with five peaks, corresponding to five instars, in conformity with Dyar's Law. Eighty-three egg masses were observed along the stream channel from 3 June to 12 November at a mean distance of 6.1 cm above the water surface in moist, protected locations such as under moss mats or in crevices of logs. Eggs began hatching by mid-summer, first-instar larvae were present in samples from AugustOctober, all five instars were represented in October, instars IIV were still present in December, but only instars IV and V were represented in samples collected from March to July. The extended periods of oviposition and larval recruitment, together with a remarkably protracted flight period of six months (29 April30 October), led to the conclusion that the population of O. ocelligera at the mine site exhibited an asynchronous univoltine life cycle. Measurement of the width of the anterior border of the frontoclypeal apotome confirmed Wiggins' proposal that this metric is useful for distinguishing final instar larvae of O. ocelligera from its only Nearctic congener, O. pardalis. Occupied pupal cases were found embedded in sodden logs from 8 April

  15. Location of Agricultural Drainage Pipes and Assessment of Agricultural Drainage Pipe Conditions Using Ground Penetrating Radar

    Methods are needed to not only locate buried agricultural drainage pipe, but to also determine if the pipes are functioning properly with respect to water delivery. The primary focus of this research project was to confirm the ability of ground penetrating radar (GPR) to locate buried drainage pipe ...

  16. Effects of coal strip mining on stream water quality and biology, southwestern Washington

    Fuste, L.A.; Meyer, D.F.


    Strip mining for coal in southwestern Washington may be affecting the water quality of streams. To investigate these possible effects, five streams were selected for study of water quality in each of the two coal bearing areas: the Centralia-Chehalis coal district, and Kelso-Castle Rock coal area. In the Centralia-Chehalis coal district, three of the streams have drainage basins in which mines are active. Water in streams that drain unmined basins is typical of western Washington streams and is characterized as a mixed water because calcium, magnesium, sodium, and bicarbonate ions predominate. A change in anionic composition from bicarbonate to sulfate in streams draining mined areas was not sufficient to change the general water composition and thus make the streams acidic. The largest downstream changes in water quality in both mined and unmined drainage basins were observed during summer low-flow conditions, when minimal dilution, increased water temperatures, and low dissolved oxygen concentrations occurred. High dissolved solids were found in the mined drainage basins during this period. High concentrations of iron, manganese, and zinc were present in the bottom sediments of the mined basins. Moderate concentrations of chromium, cobalt, copper, and zinc were also found in the bottom sediments of a few unmined basins. Streams with substrates of gravel-cobble or gravel-coarse sand had the most diverse benthic fauna and a higher number of ubiquitous taxa than streams with sand-silt substrates, which had the most dissimilar fauna. Mayflies, stoneflies, and caddisflies were rare at the site most affected by mining. The erosion potential of a basin appears to be related to the average basin slope and the amount of forested areas. Strip mining for coal in steep basins may lead to massive movements of unconsolidated spoils after vegetal cover is removed if the land disturbed is graded to pre-mining slopes. (Lantz-PTT)

  17. Longitudinal profile and sediment mobility as geomorphic tools to interpret the history of a fluviokarst stream system

    John Woodside


    Full Text Available The complex drainage systems within karst settings can result in atypical longitudinal profiles. Features, such as cave entrances, can be expressed as anomalous ‘bumps’ in the longitudinal profile of a stream if downcutting has continued upstream of the area in which the water is pirated to the subsurface. Horn Hollow, a fluviokarst valley located in Carter Caves State Park Resort in northeastern Kentucky, was examined for these types of features. The objectives of this study were to determine if sediment mobility can be used as a proxy for anomalous areas along the profile of the valley and if detailed cross-sections can reveal and/or differentiate areas of cave collapse from natural down-cutting of the system. To accomplish these objectives, the longitudinal profile of Horn Hollow and numerous cross-sections through the valley were surveyed. Armor point counts were performed at cross-sections unless the section was predominantly bedrock. Although Horn Hollow’s waters have been predominantly pirated to the subsurface, the longitudinal profile of the system is graded to that of a stream near equilibrium, but anomalous areas are present. The progression of sediment size along the length of the profile does not follow a typical fining-downstream pattern. Some of the largest sediments can be found within the lower segment of the profile. Taken together, the anomalous bumps and the sediment size suggest that the shape of the longitudinal stream profile is strongly influenced by karst processes such as stream piracy and cave collapse.

  18. Urban Drainage Modeling and Flood Risk Management

    Schmitt, Theo G.; Thomas, Martin

    The European research project in the EUREKA framework, RisUrSim (Σ!2255) has been worked out by a project consortium including industrial mathematics and water engineering research institutes, municipal drainage works as well as an insurance company. The overall objective has been the development of a simulation to allow flood risk analysis and cost-effective management for urban drainage systems. In view of the regulatory background of European Standard EN 752, the phenomenon of urban flooding caused by surcharged sewer systems in urban drainage systems is analyzed, leading to the necessity of dual drainage modeling. A detailed dual drainage simulation model is described based upon hydraulic flow routing procedures for surface flow and pipe flow. Special consideration is given to the interaction between surface and sewer flow in order to most accurately compute water levels above ground as a basis for further assessment of possible damage costs. The model application is presented for small case study in terms of data needs, model verification, and first simulation results.

  19. Modeling and clustering users with evolving profiles in usage streams

    Zhang, Chongsheng


    Today, there is an increasing need of data stream mining technology to discover important patterns on the fly. Existing data stream models and algorithms commonly assume that users\\' records or profiles in data streams will not be updated or revised once they arrive. Nevertheless, in various applications such asWeb usage, the records/profiles of the users can evolve along time. This kind of streaming data evolves in two forms, the streaming of tuples or transactions as in the case of traditional data streams, and more importantly, the evolving of user records/profiles inside the streams. Such data streams bring difficulties on modeling and clustering for exploring users\\' behaviors. In this paper, we propose three models to summarize this kind of data streams, which are the batch model, the Evolving Objects (EO) model and the Dynamic Data Stream (DDS) model. Through creating, updating and deleting user profiles, these models summarize the behaviors of each user as a profile object. Based upon these models, clustering algorithms are employed to discover interesting user groups from the profile objects. We have evaluated all the proposed models on a large real-world data set, showing that the DDS model summarizes the data streams with evolving tuples more efficiently and effectively, and provides better basis for clustering users than the other two models. © 2012 IEEE.


    Walter Collischonn


    Full Text Available The development and improvement of Geographic Information Systems and geoprocessing algorithms,together with the increase in computational capacity and data availability from remote sensing, becamepossible to prepare information for hydrologic studies of large areas with relative low cost and incrediblespeed. This paper describes the use of SRTM data to derive drainage network and related products, suchas accumulated drainage areas and river lengths, with application to the Uruguay river basin. Six distinctDigital Elevation Models (DEMs were used, varying the spatial resolution and applying the stream burningpre-processing technique. The main limitations of the DEM-derived drainage network refer to the incapacityof representing river meanders that are smaller than the pixel size and the problem of artificial sinuosity thatoccurs when the width of the river is larger than pixel side.

  1. Processes of Salt Transport in Disturbed Streams

    Chitrakar, S.; Miller, S. N.; Caffrey, P. A.; Stern, J.


    The extraction of coal bed methane natural gas involves removal of large amount of ground/Coal Bed Methane (CBM) water which is commonly discharged to surface-water drainages or constructed reservoirs. The extraction of large volume of water and its disposal on soil surface not only lowers the water table but also potentially accelerate soil erosions, contaminate surface water resources, and alter the natural flows. Due to the difference in quality and quantity between the surface discharge and disposed CBM water, this management strategy potentially poses threats to quality of surface water and soil. CBM discharge water typically contains high concentrations of sodium and low concentrations of calcium and magnesium, resulting in high sodium adsorption ratio (SAR). Similarly, it also contains high concentration of other ions which could results in increasing salt concentrations. Our study area is in the Atlantic Rim development area of the Muddy Creek, SE of Wyoming, a tributary to Colorado River, where significant development of CBM wells is ongoing. Since Muddy Creek is part of the Upper Colorado River, the greatest concern is its potential to contribute to surface water quality (primarily salinity) impairment downstream. However, very few studies have made efforts to assess the water quality in this particular region. The alteration of stream water quality in this region is still not fully understood if it due to CBM water discharge or via soil/water interactions, erosion, and sediment transport. Efforts are being made to identify crucial water quality parameters such as SAR and EC along with the quantification of solute/salt loadings at both CBM discharge fed streams and natural streams at different seasons to distinguish effect of CBM discharge on water quality. We have been continuously monitoring water quality on monthly basis and discharge measurement on daily basis at sampling sites that are placed to discriminate CBM fed streams and natural streams. The

  2. Chemical quality of surface waters, and sedimentation in the Grand River drainage basin, North and South Dakota

    Hembree, Charles Herbert; Krieger, Robert A.; Jordan, Paul Robert


    An investigation of the chemical quality of surface waters and of the sedimentation in the Grand River drainage basin by the U.S. Geological Survey began in 1946. The chemical quality of the water was studied to obtain information on the nature and amounts of dissolved solids in the streams and on the suitability of the water for domestic, industrial, and irrigation uses. Sedimentation was studied to determine the quantity of sediment that is transported by the streams, the particle sizes of the sediment, and the probable specific weight of the sediment when deposited in a reservoir.

  3. Percent Agriculture Adjacent to Streams

    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...

  4. Percent Forest Adjacent to Streams

    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...

  5. Occurrence of azoxystrobin, propiconazole, and selected other fungicides in US streams, 2005-2006

    Battaglin, William A.; Sandstrom, Mark W.; Kuivila, Kathryn M.; Kolpin, Dana W.; Meyer, Michael T.


    Fungicides are used to prevent foliar diseases on a wide range of vegetable, field, fruit, and ornamental crops. They are generally more effective as protective rather than curative treatments, and hence tend to be applied before infections take place. Less than 1% of US soybeans were treated with a fungicide in 2002 but by 2006, 4% were treated. Like other pesticides, fungicides can move-off of fields after application and subsequently contaminate surface water, groundwater, and associated sediments. Due to the constant pressure from fungal diseases such as the recent Asian soybean rust outbreak, and the always-present desire to increase crop yields, there is the potential for a significant increase in the amount of fungicides used on US farms. Increased fungicide use could lead to increased environmental concentrations of these compounds. This study documents the occurrence of fungicides in select US streams soon after the first documentation of soybean rust in the US and prior to the corresponding increase in fungicide use to treat this problem. Water samples were collected from 29 streams in 13 states in 2005 and/or 2006, and analyzed for 12 target fungicides. Nine of the 12 fungicides were detected in at least one stream sample and at least one fungicide was detected in 20 of 29 streams. At least one fungicide was detected in 56% of the 103 samples, as many as five fungicides were detected in an individual sample, and mixtures of fungicides were common. Azoxystrobin was detected most frequently (45% of 103 samples) followed by metalaxyl (27%), propiconazole (17%), myclobutanil (9%), and tebuconazole (6%). Fungicide detections ranged from 0.002 to 1.15 μ/L. There was indication of a seasonal pattern to fungicide occurrence, with detections more common and concentrations higher in late summer and early fall than in spring. At a few sites, fungicides were detected in all samples collected suggesting the potential for season-long occurrence in some streams

  6. Historical evolution of the drainage network at the basin scale using aerial orthophotography in Southern Spain

    Castillo, Carlos; Mora, Jose; Gómez, Jose Alfonso


    Soil management has major implications on the drainage systems in agricultural catchments. Management practices, such as ploughing the gully perimeter and gully filling, remove the vegetation and natural features associated with natural streams contributing to the landscape simplification and accelerating erosion processes. This study evaluated the temporal evolution of several key parameters of the drainage network at the Arroyo Galapagares basin over a period of six decades, from a set of existing orthophotographies, since the first available (1956) to the present (2011). The area of the catchment is 80 km2, being representative of the Campiña, a rolling landscape covered by field crops on mostly Vertisol soils, in Southern Spain. The complete drainage network of the basin was digitized, defining the thalweg and the perimeter of the channels. Since the distinction between the actual channel surface and surrounding weed-covered surface is not reliable by means of merely orthophotography inspection, the limits between the field crops and the drainage network surface provided a measure of the magnitude of non-cultivated areas. Using the digitization results, the temporal variation of three parameters were assessed: network length, channel sinuosity and non-cultivated surface. The results of this analysis showed that a significant reduction of sinuosity occurred during the study period, as well as temporary decreases in the network length as a consequence of land levelling and gully filling. Moreover, a sustained growth of non-cultivated areas was observed at the upstream gullies (low-level order streams) due to the intensification of gully erosion, especially during the last decade.

  7. Autogenic Drainage in Children With Cystic Fibrosis.

    Corten, Lieselotte; Morrow, Brenda M


    Airway clearance is an essential part of the management of cystic fibrosis (CF) as it facilitates clearance of viscous pulmonary secretions. This review aimed to determine the effect of autogenic drainage (AD) and assisted autogenic drainage (AAD) compared with no, sham, or other types of airway clearance in children with CF. Two pediatric randomized cross-over trials were identified on the use of AD in children with CF; no studies were available on the use of AAD. In one study AD had a positive influence on the Huang score, and is preferred over postural drainage in this population. We could not determine the efficacy of AD and AAD in children with CF. We recommend the implementation of pediatric-specific randomized controlled trials with adequate sample sizes, appropriate clinical outcome measures, and analysis of adverse effects.

  8. [Methods of internal drainage of pancreatic pseudocysts].

    Starkov, Yu G; Solodinina, E N; Zamolodchikov, R D


    To present own experience of internal drainage and characteristics of its different variants which are applied in various countries. Endosonography-assisted internal drainage of pancreatic pseudocysts was performed in 25 patients. Plastic stents were implanted in one stage without change of instruments while metal stents - with change of instruments during manipulation. Intervention was successful in 24 patients. In 1 case bleeding developed during cystostomy that required open surgery. Plastic and metal stents were used in 11 and 12 patients respectively. 1 patient had two pancreatic pseudocysts. Therefore 2 stents of both types were used in this case. Clinical success was achieved in 91% of cases. Different variants of method resolve problem of surgical approach, stomy and choice of stent. However every technique is targeted to resolve separate problem while single method is not accepted. Further large comparative studies are necessary to define optimal technique of internal drainage.

  9. Percutaneous epidural drainage through a burr hole

    Priscila M Falsarella


    Full Text Available Intracranial extradural collection may cause an increase in intracranial pressure, requiring rapid emergency treatment to reduce morbidity and mortality. We described an alternative CT-guided percutaneous access for extradural collection drainage. We report a case of a patient with previous craniectomy for meningioma ressection who presented to the Emergency Department with symptoms of intracranial hypertension. Brains CT showed a extradural collection with subfalcine herniation. After multidisciplinary discussion a CT-guided percutaneous drainage through previous burr hole was performed. The patient was discharged after 36 hours of admission, without further symptoms. We describe a safe and effective alternative percutaneous access for extradural collection drainage in patients with previous burr hole.

  10. Gill lesions and death of bluegill in an acid mine drainage mixing zone

    Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Brumbaugh, W.G.; Wildhaber, M.L. [Auburn University, Auburn, AL (United States). Alabama Cooperative of Fish & Wildlife Research Unit


    The toxicity of an acid mine drainage (AMD) mixing zone was investigated by placing bluegill (Lepomis macrochirus) at the confluence of a stream contaminated by AMD and a stream having neutral pH. A mixing channel receiving water from both streams was assembled in the field, during July and October 1996, to determine the toxicity of freshly mixed and aged water (2.9-7.5 min). The AMD stream had elevated concentrations of Al and Fe, which precipitated upon mixing, and of Mn, which did not precipitate in the mixing zone. Fish exposed to freshly mixed water had higher mortality than fish exposed to water after aging. Precipitating Al, but not Fe, accumulated on the gills of bluegill, and accumulation was more rapid early during the mixing process than after aging. Fish exposed for 3.5 h to freshly mixed water had hypertrophy and hyperplasia of gill filament and lamellar epithelial cells. Similar lesions were observed after 6.0 h in fish exposed to water aged after mixing. Results demonstrated that Al was the predominant metal accumulating on the gills of fish in this AMD mixing zone, and that mixing zones can be more toxic than AMD streams in equilibrium.

  11. Water quality, fate of metals and predictive model validation of a constructed wetland treating acid mine drainage

    Mitsch, W.J.; Wise, K.M. [Ohio State University, Columbus, OH (United States). School of Natural Resources


    The paper describes how 0.39 ha constructed wetland designed with 9 cells, including two anaerobic cells that were to stimulate dissimilatory sulfate reduction, was evaluated for its effect on water quality of a low-order acid mine drainage (AMD) stream in southeastern Ohio, USA. Emphasis was on the uptake and fate of selected metals and the accuracy of a simulation model that predicted this specific wetland`s behavior before it was built.

  12. Analytic Strategies of Streaming Data for eHealth.

    Yoon, Sunmoo


    New analytic strategies for streaming big data from wearable devices and social media are emerging in ehealth. We face challenges to find meaningful patterns from big data because researchers face difficulties to process big volume of streaming data using traditional processing applications.1 This introductory 180 minutes tutorial offers hand-on instruction on analytics2 (e.g., topic modeling, social network analysis) of streaming data. This tutorial aims to provide practical strategies of information on reducing dimensionality using examples of big data. This tutorial will highlight strategies of incorporating domain experts and a comprehensive approach to streaming social media data.

  13. Geomorphic characteristics and classification of Duluth-area streams, Minnesota

    Fitzpatrick, Faith A.; Peppler, Marie C.; DePhilip, Michele M.; Lee, Kathy E.


    In 2003 and 2004, a geomorphic assessment of streams in 20 watersheds in the Duluth, Minn., area was conducted to identify and summarize geomorphic characteristics, processes, disturbance mechanisms, and potential responses to disturbance. Methods used to assess the streams included watershed characterization, descriptions of segment slopes and valley types, historical aerial photograph interpretation, and rapid field assessments and intensive field surveys of stream reaches. Geomorphic conditions were summarized into a segment-scale classification with 15 categories mainly based on drainage-network position and slope, and, secondarily, based on geologic setting, valley type, and dominant geomorphic processes. Main causes of geomorphic disturbance included historical logging and agriculture, and ongoing urban development, human-caused channel alterations, road and storm sewer drainage, ditching, hiking trails, and gravel pits or quarries. Geomorphic responses to these disturbances are dependent on a combination of drainage-network position, slope, and geologic setting. Geologic setting is related to drainage-network position because the geologic deposits parallel the Lake Superior shoreline. Headwater streams in large watersheds flow over glacial deposits above altitudes of about 1,200 feet (ft). Headwater tributaries and upper main stems have ditch-like channels with gentle slopes and no valleys. Urban development and road drainage cause increased runoff and flood peaks in these segments resulting in channel widening. Below about 1,200 ft, main-stem segments generally are affected by bedrock type and structure and have steep slopes and confined or entrenched valleys. Increases in flood peaks do not cause incision or widening in the bedrock-controlled valleys; instead, the flow and scour areas are expanded. Feeder tributaries to these main stems have steep, confined valleys and may be sources for sediment from urban areas, road runoff, or storm sewer outfalls. Main

  14. Water quality of streams draining abandoned and reclaimed mined lands in the Kantishna Hills area, Denali National Park and Preserve, Alaska, 2008–11

    Brabets, Timothy P.; Ourso, Robert T.


    The Kantishna Hills are an area of low elevation mountains in the northwest part of Denali National Park and Preserve, Alaska. Streams draining the Kantishna Hills are clearwater streams that support several species of fish and are derived from rain, snowmelt, and subsurface aquifers. However, the water quality of many of these streams has been degraded by mining. Past mining practices generated acid mine drainage and excessive sediment loads that affected water quality and aquatic habitat. Because recovery through natural processes is limited owing to a short growing season, several reclamation projects have been implemented on several streams in the Kantishna Hills region. To assess the current water quality of streams in the Kantishna Hills area and to determine if reclamation efforts have improved water quality, a cooperative study between the U.S. Geological Survey and the National Park Service was undertaken during 2008-11. High levels of turbidity, an indicator of high concentrations of suspended sediment, were documented in water-quality data collected in the mid-1980s when mining was active. Mining ceased in 1985 and water-quality data collected during this study indicate that levels of turbidity have declined significantly. Turbidity levels generally were less than 2 Formazin Nephelometric Units and suspended sediment concentrations generally were less than 1 milligram per liter during the current study. Daily turbidity data at Rock Creek, an unmined stream, and at Caribou Creek, a mined stream, documented nearly identical patterns of turbidity in 2009, indicating that reclamation as well as natural revegetation in mined streams has improved water quality. Specific conductance and concentrations of dissolved solids and major ions were highest from streams that had been mined. Most of these streams flow into Moose Creek, which functions as an integrator stream, and dilutes the specific conductance and ion concentrations. Calcium and magnesium are the

  15. Greenland subglacial drainage evolution regulated by weakly connected regions of the bed

    Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen A.; Catania, Ginny A.; Neumann, Thomas A.; Lüthi, Martin P.; Gulley, Jason; Ryser, Claudia; Hawley, Robert L.; Morriss, Blaine


    Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

  16. Greenland Subglacial Drainage Evolution Regulated by Weakly Connected Regions of the Bed

    Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen F.; Catania, Ginny A.; Neumann, Thomas A.; Luthi, Martin P.; Gulley, Jason; Ryser, Claudia; Hawley, Robert L.; Morriss, Blaine


    Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

  17. Academic streaming in Europe

    Falaschi, Alessandro; Mønster, Dan; Doležal, Ivan;


    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....

  18. Gas drainage technology of high gas and thick coal seam

    HE Tian-cai; LI Hai-gui; ZHANG Hai-jun


    Gas drainage in Jincheng Mining Group Co., Ltd. was introduced briefly and the importance of gas drainage in gas control was analyzed. Combined with coal-bed gas oc-currence and gas emission, the double system of gas drainage was optimized and a pro-gressive gas drainage model was experimented on. For guaranteed drainage, excavation and mining and realization of safety production and reasonable exploitation of gas in coal seams, many drainage methods were adopted to solve the gas problem of the working face.

  19. Use of Natural and Applied Tracers to Guide Targeted Remediation Efforts in an Acid Mine Drainage System, Colorado Rockies, USA

    Rory Cowie


    Full Text Available Stream water quality in areas of the western United States continues to be degraded by acid mine drainage (AMD, a legacy of hard-rock mining. The Rico-Argentine Mine in southwestern Colorado consists of complex multiple-level mine workings connected to a drainage tunnel discharging AMD to passive treatment ponds that discharge to the Dolores River. The mine workings are excavated into the hillslope on either side of a tributary stream with workings passing directly under the stream channel. There is a need to define hydrologic connections between surface water, groundwater, and mine workings to understand the source of both water and contaminants in the drainage tunnel discharge. Source identification will allow targeted remediation strategies to be developed. To identify hydrologic connections we employed a combination of natural and applied tracers including isotopes, ionic tracers, and fluorescent dyes. Stable water isotopes (δ18O/δD show a well-mixed hydrological system, while tritium levels in mine waters indicate a fast flow-through system with mean residence times of years not decades or longer. Addition of multiple independent tracers indicated that water is traveling through mine workings with minimal obstructions. The results from a simultaneous salt and dye tracer application demonstrated that both tracer types can be successfully used in acidic mine water conditions.

  20. Persistence of Metal-rich Particles Downstream Zones of Acid Drainage Mixing in Andean Rivers

    Pasten, P.; Montecinos, M.; Guerra, P. A.; Bonilla, C. A.; Escauriaza, C. R.; Dabrin, A.; Coquery, M.


    The Andes mountain range provides the setting for watersheds with high natural background of metals and for mining operations that enhance contaminant mobilization, notably in Northern and Central Chile. Dissolved and solid metal species are actively transported by streams to the Pacific Ocean from area and point sources, like acid drainage. We examine the response of metal rich particle suspensions downstream zones of mixing where shifts in the chemical environment occur. We propose a conceptual model which is used to analyze the fate of copper in the upper Mapocho watershed. The main source of copper is the Yerba Loca river, a naturally impacted stream with pH ranging from 3 to 7 and high concentrations of Cu (0.8 - 6.3 mg/L), Al (1.3 - 7.6 mg/L) and Fe (0.4 - 4.2 mg/L). Steep chemical shifts occur after the confluences with the San Francisco and the Molina rivers. We characterized stream chemistry, hydrological variables and suspended particles, including particle size distribution (PSD), turbidity, and total suspended solids. A marked seasonal behavior was observed, with a higher total Cu flux during smelting periods and a shift towards the dissolved phase during summer. When acid drainage is discharged into a receiving stream, incomplete mixing occurs thereby promoting the formation of a range of metal-rich solids with a characteristic PSD. Similarly, areas of chemical heterogeneity control the partition of metals associated to suspended geomaterials coming from bank and slope erosion. A highly dynamic process ensues where metastable phases shift to new equilibria as fully mixed conditions are reached. Depending on the reaction kinetics, some particles persist despite being exposed to thermodynamically unfavorable chemical environments. The persistence of metal-rich particles downstream zones of acid drainage mixing is important because it ultimately controls the flux of metals being delivered to the ocean by watersheds impacted by acid drainage. Funding from

  1. Impact of subsurface drainage on streamflows in the Red River of the North basin

    Rahman, Mohammed M.; Lin, Zhulu; Jia, Xinhua; Steele, Dean D.; DeSutter, Thomas M.


    The debate about subsurface drainage effects on streamflows has been reignited in the Red River of the North basin in North America, after a decades-long abnormally wet weather pattern in the region. Our study evaluated the applicability of the Soil and Water Assessment Tool (SWAT) in modeling subsurface drainage in a cold environment; we then employed streamflow response analyses to assess the potential impacts of the extensive subsurface drainage development in the Red River Valley (RRV) on streamflows in the Red River. The results showed that extensive subsurface drainage in the RRV would likely increase the magnitude of smaller peak flows while decreasing the magnitude of larger peak flows. Discharge reduction of large peak flows was mainly caused by reducing the flow volumes rather than increasing the time-to-peak of the hydrograph. Our analysis also suggested that extensive subsurface drainage could move more water from the watershed to the rivers in the fall season, creating more storage capacity in the soils. However, such increase in storage capacity in soils would have a negligible effect in reducing the monthly flow volumes in the following spring. The proposed method of coupling a watershed model with streamflow response analysis can be readily adopted by other researchers to evaluate the streamflow impact of land-use and climate changes around the world.

  2. Phospholipid Analyses for Microbial Community Composition in Alpine Acid Rock Drainage

    Webster, C. E.; Tapp, J. B.; Pfiffner, S. M.


    This project is examining factors of non-anthropogenic acid rock drainage that influence microbial community composition in the Peekaboo Gulch drainage basin (Sawatch Range, Colorado). At this site, natural acid rock drainage outflows from acidic springs (pH=2.6) on Red Mountain. The acid drainage converges with South Fork Lake Creek (pH ~ 7.0, prior to convergence) two miles down gradient. Sediment samples were collected across confluences with gradient of pH, temperature, conductivity and metal concentration. In-situ parameter measurements ranged from 2.3 to 7.9 of pH, 3.8 to 16.6 degree Celsius for temperature, and 34.9 to 1820 for conductivity. Biomass as measured by phospholipids ranged from 280 to 95,900 pmol/g sediment. The only relationship between the in situ parameters and the phospholipid profiles is a weak positive correlation between pH and branched monounsaturated fatty acid methyl esters in that at a pH greater than 5.0 these fatty acid methyl esters were detected. The phospholipid profiles were diverse across the samples. These profiles changed with respect to the spatial relationship within the drainage pattern. The highest alpine samples contained greater relative abundances of monounsaturated fatty acid methyl esters compared to the lower alpine samples. Microbial community profiles shifted at each confluence depending on water source chemistry. Continuing research is needed to determine other biogeochemical factors that may influence these community shifts.

  3. Local and synoptic controls on rapid supraglacial lake drainage in West Greenland

    Williamson, Andrew; Banwell, Alison; Arnold, Neil; Willis, Ian


    Many supraglacial lakes within the ablation zone of the Greenland Ice Sheet (GrIS) are known to drain rapidly (in scale factors, such as ice thickness, driving stresses, ice velocities and strain rates. A combination of the local water-volume threshold and one or more synoptic-scale factors may explain the overall patterns of rapid lake drainage, but this requires verification using targeted field- and remotely-based studies that cover large areas of the GrIS and span long timescales. Here, we investigate a range of potential controls on rapid supraglacial lake drainage in the land-terminating Paakitsoq region of the ice sheet, northeast of Jakobshavn Isbræ, for the 2014 melt season. We have analysed daily 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) imagery in order to calculate lake areas, depths and volumes, and have developed an automatic lake-tracking algorithm to determine the dates on which all rapid lake drainage events occur. For each rapidly draining lake, the water volumes immediately prior to drainage are compared with other local factors, notably lake-filling rate and ice thickness, and with a variety of synoptic-scale features, such as slope angles, driving stresses, surface velocities, surface strain rates and the incidence of nearby lake-drainage events. We present the outcomes of our statistical analysis to elicit the statistically significant controls on hydrofracture beneath supraglacial lakes.

  4. Tropospheric ozone in the Nisqually River Drainage, Mount Rainier National Park

    Peterson, D.L.; Bowers, Darci


    We quantified the summertime distribution of tropospheric ozone in the topographically complex Nisqually River drainage of Mount Rainier National Park from 1994 to 1997. Passive ozone samplers were used along an elevational transect to measure weekly average ozone concentrations ranging from 570 m to 2040 m elevation. Weekly average ozone concentrations were positively correlated with elevation, with the highest concentrations consistently measured at the highest sampling site (Panorama Point). Weekly average ozone concentrations at Mount Rainier National Park are considerably higher than those in the Seattle-Tacoma metropolitan area to the west. The anthropogenic contribution to ozone within the Nisqually drainage was evaluated by comparing measurements at this location with measurements from a 'reference' site in the western Olympic Mountains. The comparison suggests there is a significant anthropogenic source of ozone reaching the Cascade Range via atmospheric transport from urban areas to the west. In addition. temporal (week to week) variation in ozone distribution is synchronous within the Nisqually drainage, which indicates that subregional patterns are detectable with weekly averages. The Nisqually drainage is likely the 'hot spot' for air pollution in Mount Rainier National Park. By using passive ozone samplers in this drainage in conjunction with a limited number of continuous analyzers, the park will have a robust monitoring approach for measuring tropospheric ozone over time and protecting vegetative and human health.

  5. Drainage integration and sediment dispersal in the actively extending central Italian Apennines

    Geurts, Anneleen H.; Cowie, Patience A.; Huismans, Ritske S.; Gawthorpe, Robert L.; Wedmore, Luke; Duclaux, Guillaume


    Evidence for re-organisation of river networks during crustal extension is observed in many (active and ancient) rifts around the world. In the actively extending central Italian Apennines, drainage integration is evidenced by the cessation of lake sedimentation in hangingwall basins and the development of drainage systems that extend from the interior of the mountain belt to the coast. We combine field data from this area on normal fault development and regional surface uplift within a landscape evolution model to investigate the process of drainage integration and its impact on regional sediment dispersal under a range of erosional conditions. We use the numerical model CASCADE (developed by Braun and Sambridge) for calculating fluvial erosion/deposition and lake filling in response to normal faulting. The fault-related topography is simulated by means of a linear elastic dislocation model, using a published map of active faults in the area. Regional surface uplift is constrained from published field observations of paleoshorelines and basin stratigraphy. Using this modeling approach we demonstrate the phenomenon of drainage integration, showing how it leads to the gradual disappearance of lakes and the transition to an inter-connected fluvial transport system. While headward erosion is often considered as the main underlying mechanism, our model results suggest a key role for basin over-filling and lake over-spilling and we discuss its implications for regional drainage network evolution. We also demonstrate how drainage integration leads to a sudden change in sediment dispersal patterns and the progressive removal of sediment from the rift interior. Overall, we use our numerical models to discuss the relative importance of tectonics and surface processes for long-term landscape evolution in the central Italian Apennines and put published field observations (e.g. local depositional patterns in rift basins) in a regional and long-term tectonic perspective.

  6. Water-quality characteristics and trend analyses for the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins, Wyoming and Montana, for selected periods, water years 1991 through 2010

    Clark, Melanie L.


    , and major ion concentrations of the main-stem streams. Sites in the Tongue River drainage basin typically had the smallest range of specific conductance and SAR values. The water chemistry of sites in the Powder River drainage basin generally was the most variable as a result of diverse characteristics of that basin. Plains tributaries in the Powder River drainage basin had the largest range of specific conductance and SAR values, in part due to the many tributaries that receive CBNG-produced waters. Trends were analyzed using the seasonal Kendall test with flow-adjusted concentrations to determine changes to water quality through time at sites in the Tongue, Powder, Cheyenne, and Belle Fourche River drainage basins. Trends were evaluated for water years 2001–10 for 17 sites, which generally were on the main-stem streams and primary tributaries. Trends were evaluated for water years 2005–10 for 26 sites to increase the spatial coverage of sites. Trends were evaluated for water years 1991–2010 for eight sites to include water-quality data collected prior to widespread CBNG development and expand the temporal context of trends. Consistent patterns were not observed in trend results for water years 2001–10 for flow-adjusted specific conductance and SAR values in the Tongue, Powder, and Belle Fourche River drainage basins. Significant (p-values less than 0.05) upward trends in flow-adjusted specific conductance values were determined for 3 sites, a downward trend was determined for 1 site, and no significant (p-value greater than 0.05) trends were determined for 13 sites. One of the sites with a significant upward trend was the Tongue River at the Wyoming-Montana State line. No trend in flow-adjusted specific conductance values was determined for the Powder River at Moorhead, Mont. Significant upward trends in flow-adjusted SAR values were determined for 2 sites and no significant trends were determined for 15 sites. No trends in flow-adjusted SAR values were

  7. Trout Stream Special Regulations

    Minnesota Department of Natural Resources — This layer shows Minnesota trout streams that have a special regulation as described in the 2006 Minnesota Fishing Regulations. Road crossings were determined using...

  8. Channelized Streams in Iowa

    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...

  9. Streaming tearing mode

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


    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.

  10. Streaming media bible

    Mack, Steve


    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...

  11. Roads Near Streams

    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...

  12. Future Roads Near Streams

    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...

  13. DNR 24K Streams

    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,...

  14. Streaming tearing mode

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


    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.

  15. Streaming Virtual Reality Content

    El-Ganainy, Tarek; Hefeeda, Mohamed


    The recent rise of interest in Virtual Reality (VR) came with the availability of commodity commercial VR prod- ucts, such as the Head Mounted Displays (HMD) created by Oculus and other vendors. To accelerate the user adoption of VR headsets, content providers should focus on producing high quality immersive content for these devices. Similarly, multimedia streaming service providers should enable the means to stream 360 VR content on their platforms. In this study, we try to cover different ...

  16. Reincarnation of Streaming Applications


    AFRL-RY-WP-TR-2009-1033 REINCARNATION OF STREAMING APPLICATIONS Saman Amarsinghe, Robert Miller, and Michael Ernst Massachusetts...2007 – 31 December 2008 4. TITLE AND SUBTITLE REINCARNATION OF STREAMING APPLICATIONS 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8650-07-C-7737 5c...Program Reincarnation , using a simple prototype. A Program Reincarnation tool will assist the programmer in replacing the program’s code (the body

  17. Hybridization of two megacephalic map turtles (testudines: emydidae: Graptemys) in the Choctawhatchee River drainage of Alabama and Florida

    Godwin, James; Lovich, Jeffrey E.; Ennen, Joshua R.; Kreiser, Brian R.; Folt, Brian; Lechowicz, Chris


    Map turtles of the genus Graptemys are highly aquatic and rarely undergo terrestrial movements, and limited dispersal among drainages has been hypothesized to drive drainage-specific endemism and high species richness of this group in the southeastern United States. Until recently, two members of the megacephalic “pulchra clade,” Graptemys barbouri andGraptemys ernsti, were presumed to be allopatric with a gap in both species' ranges in the Choctawhatchee River drainage. In this paper, we analyzed variation in morphology (head and shell patterns) and genetics (mitochondrial DNA and microsatellite loci) from G. barbouri, G. ernsti, and Graptemys sp. collected from the Choctawhatchee River drainage, and we document the syntopic occurrence of those species and back-crossed individuals of mixed ancestry in the Choctawhatchee River drainage. Our results provide a first counter-example to the pattern of drainage-specific endemism in megacephalic Graptemys. Geologic events associated with Pliocene and Pleistocene sea level fluctuations and the existence of paleo-river systems appear to have allowed the invasion of the Choctawhatchee system by these species, and the subsequent introgression likely predates any potential human-mediated introduction.

  18. Urban drainage models - making uncertainty analysis simple

    Vezzaro, Luca; Mikkelsen, Peter Steen; Deletic, Ana


    There is increasing awareness about uncertainties in modelling of urban drainage systems and, as such, many new methods for uncertainty analyses have been developed. Despite this, all available methods have limitations which restrict their widespread application among practitioners. Here, a modif...

  19. 24 CFR 3280.610 - Drainage systems.


    ... designs the system for site assembly and also provides all materials and components, including piping... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Drainage systems. 3280.610 Section 3280.610 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued...

  20. Reality named endoscopic ultrasound biliary drainage

    Hugo; Gon?alo; Guedes; Roberto; Iglesias; Lopes; Joel; Fernandez; de; Oliveira; Everson; Luiz; de; Almeida; Artifon


    Endoscopic ultrasound(EUS) is used for diagnosis and evaluation of many diseases of the gastrointestinal (GI) tract. In the past, it was used to guide a cholangio-graphy, but nowadays it emerges as a powerful thera-peutic tool in biliary drainage. The aims of this review are: outline the rationale for endoscopic ultrasound-guided biliary drainage(EGBD); detail the procedural technique; evaluate the clinical outcomes and limitations of the method; and provide recommendations for the practicing clinician. In cases of failed endoscopic retro-grade cholangiopancreatography(ERCP), patients are usually referred for either percutaneous transhepatic biliary drainage(PTBD) or surgical bypass. Both these procedures have high rates of undesirable complications. EGBD is an attractive alternative to PTBD or surgery when ERCP fails. EGBD can be performed at two locations: transhepatic or extrahepatic, and the stent can be inserted in an antegrade or retrograde fashion. The drainage route can be transluminal, duodenal or trans-papillary, which, again, can be antegrade or retrograde [rendezvous(EUS-RV)]. Complications of all techniques combined include pneumoperitoneum, bleeding, bile leak/peritonitis and cholangitis. We recommend EGBD when bile duct access is not possible because of failed cannulation, altered upper GI tract anatomy, gastric outlet obstruction, a distorted ampulla or a periampullary diverticulum, as a minimally invasive alternative to surgery or radiology.

  1. [Artificial drainage devices--history, indications].

    Barac, Ileana Ramona; Pop, Monica


    Glaucoma is a degenerative optic neuropathy progressive, multifactorial, which can lead to blindness. Blindness in patients with glaucoma is defined as visual field reduction below 10 degrees. Artificial drainage systems are a solution for refractory to medication, laser treatment or conventional surgery. Used by over 100 years, improved with good surgical technique and careful patient follow-up surgery, postoperative results are satisfactory.

  2. Optimizing the closed suction surgical drainage system.

    Carruthers, Katherine H; Eisemann, Bradley S; Lamp, Susan; Kocak, Ergun


    Closed suction drains are indicated in a wide array of postoperative settings, with many distinct drainage systems available to the surgeon. The purpose of this study was to compare the suction gradients achieved using 2 different sizes of suction reservoirs and 2 different techniques for generating negative pressure. Drainage reservoirs of 100 and 400 ml were chosen to evaluate their ability to achieve suction. Suction was established in both sizes of drains by pressing the sides of the reservoir together or by pushing the bottom of the reservoir toward the top. Negative pressures were recorded with the reservoir empty, and after every 10-ml addition of saline. Averages were graphed to illustrate the applied suction over a range of drain volumes. The 100-ml drainage system reached a peak suction of -117.6 mmHg, while the 400-ml drainage system reached only a peak suction of -71.4 mmHg. Both of the maximum suction readings were achieved using the full-squeeze technique. The bottom-pushed-in technique did not result in any sustained measurable levels of suction using either of the reservoir volumes. Smaller drain reservoirs are more successful in generating a high initial suction than larger reservoirs, especially when the volume of fluid in the drain is relatively low. In all sizes of drains, compressing the sides of the reservoir is a far better technique for establishing negative pressure than pressing the bottom of the drain up toward the top.

  3. Selecting the drainage method for agricultural land

    Bos, M.G.


    To facilitate crop growth excess water should be drained from the rooting zone to allow root development of the crop and from the soil surface to facilitate access to the field. Basically, there are three drainage methods from which the designer can select being; surface drains, pumped tube wells an

  4. Drainage hydraulics of permeable friction courses

    Charbeneau, Randall J.; Barrett, Michael E.


    This paper describes solutions to the hydraulic equations that govern flow in permeable friction courses (PFC). PFC is a layer of porous asphalt approximately 50 mm thick that is placed as an overlay on top of an existing conventional concrete or asphalt road surface to help control splash and hydroplaning, reduce noise, and enhance quality of storm water runoff. The primary objective of this manuscript is to present an analytical system of equations that can be used in design and analysis of PFC systems. The primary assumptions used in this analysis are that the flow can be modeled as one-dimensional, steady state Darcy-type flow and that slopes are sufficiently small so that the Dupuit-Forchheimer assumptions apply. Solutions are derived for cases where storm water drainage is confined to the PFC bed and for conditions where the PFC drainage capacity is exceeded and ponded sheet flow occurs across the pavement surface. The mathematical solutions provide the drainage characteristics (depth and residence time) as a function of rainfall intensity, PFC hydraulic conductivity, pavement slope, and maximum drainage path length.

  5. Interventional radiology in the lacrimal drainage system

    Ilgit, Erhan T. [Department of Radiology, School of Medicine, Gazi University, Besevler 06510, Ankara (Turkey)]. E-mail:; Oenal, Baran [Department of Radiology, School of Medicine, Gazi University, Besevler 06510, Ankara (Turkey); Coskun, Bilgen [Department of Radiology, School of Medicine, Gazi University, Besevler 06510, Ankara (Turkey)


    This article presents a review of the interventional radiological procedures in the lacrimal drainage system. Balloon dacryocystoplasty and nasolacrimal polyurethane stent placement are the main fluoroscopically guided interventions for the treatment of epiphora by recanalizing the obstructed LDS. These procedures can also be used for dacryolith removal and lacrimal sac abscess treatment.

  6. A generic hydrological model for a green roof drainage layer.

    Vesuviano, Gianni; Stovin, Virginia


    A rainfall simulator of length 5 m and width 1 m was used to supply constant intensity and largely spatially uniform water inflow events to 100 different configurations of commercially available green roof drainage layer and protection mat. The runoff from each inflow event was collected and sampled at one-second intervals. Time-series runoff responses were subsequently produced for each of the tested configurations, using the average response of three repeat tests. Runoff models, based on storage routing (dS/dt = I-Q) and a power-law relationship between storage and runoff (Q = kS(n)), and incorporating a delay parameter, were created. The parameters k, n and delay were optimized to best fit each of the runoff responses individually. The range and pattern of optimized parameter values was analysed with respect to roof and event configuration. An analysis was performed to determine the sensitivity of the shape of the runoff profile to changes in parameter values. There appears to be potential to consolidate values of n by roof slope and drainage component material.

  7. A comparative analysis on the effects of river discharge on trophic interactions in two tropical streams

    Weliange, W.S.; Amarasinghe, Upali; Vijverberg, J.; Leichtfried, M.; Füreder, L.


    Discharge-mediated seasonal patterns of food web interactions were investigated in two streams in Sri Lanka; Eswathu Oya (a perennial wet-zone stream) and Yan Oya (a seasonal dry-zone stream). Based on volumetric proportions of diet composition, relative abundance of fish species and their daily foo

  8. An evaluation of underwater epoxies to permanently install temperature sensors in mountain streams

    Daniel J. Isaak; Dona L. Horan


    Stream temperature regimes are of fundamental importance in understanding the patterns and processes in aquatic ecosystems, and inexpensive digital sensors provide accurate and repeated measurements of temperature. Most temperature measurements in mountain streams are made only during summer months because of logistical constraints associated with stream access and...

  9. Improved stream temperature simulations within SWAT using NSGA-II for automatic, multi-site calibration

    Stream temperature is one of the most influential parameters impacting the survival, growth rates, distribution, and migration patterns of many aquatic organisms. Distributed stream temperature models are crucial for providing insights into variations of stream temperature for regions and time perio...

  10. Gulf stream separation dynamics

    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.

  11. Variation in summer nitrogen and phosphorus uptake among Siberian headwater streams

    John D. Schade


    Full Text Available Arctic streams are likely to receive increased inputs of dissolved nutrients and organic matter from thawing permafrost as climate warms. Documenting how Arctic streams process inorganic nutrients is necessary to understand mechanisms that regulate watershed fluxes of permafrost-derived materials to downstream ecosystems. We report on summer nitrogen (N and phosphorus (P uptake in streams draining upland soils from the Pleistocene, and lowland floodplain soils from the Holocene, in Siberia's Kolyma River watershed. Uptake of N and P differed between upland and floodplain streams, suggesting topographic variation in nutrient limitation. In floodplain streams, P uptake rate and uptake velocity were higher than N, while upland streams had similar values for all N and P uptake metrics. Phosphorus uptake velocity and size of the transient hydrologic storage zone were negatively related across all study streams, indicating strong influence of hydrologic processes on nutrient fluxes. Physical sorption of P was higher in floodplain stream sediments relative to upland stream sediments, suggesting more physically driven uptake in floodplain streams and higher biological activity in upland streams. Overall, these results demonstrate that high-latitude headwater streams actively retain N and P during summer base flows; however, floodplain and upland streams varied substantially in N and P uptake and may respond differently to inorganic nutrient and organic matter inputs. Our results highlight the need for a comprehensive assessment of N and P uptake and retention in Arctic streams in order to fully understand the impact of permafrost-derived materials on ecosystem processes, and their fate in continental drainage networks.

  12. Exit and Paradise Creek Drainage Area Boundaries, Alaska, 2012

    U.S. Geological Survey, Department of the Interior — This dataset contains drainage area boundaries for Exit Creek and Paradise Creek in Kenai Fjords National Park, Alaska. A drainage area boundary identifies the land...

  13. Clinical outcome of routine drainage in simple laparoscopic cholecystectomy

    LIANG Zongchao


    Full Text Available ObjectiveTo retrospectively review outcomes of elective laparoscopic cholecystectomy (LC to evaluate the benefit of routine drainage in uncomplicated surgeries. MethodsTwo-hundred-and-ninety-five patients with cholecystolithiasis or gallbladder polyps who underwent LC with drainage (n=145 and or without drainage (n=150 between 2009 and 2011 were enrolled in the study. The decision for drainage was randomized. ResultsThe LC without drainage group had significantly shorter time to first flatus and shorter length of postoperative hospital stay than the LC with drainage group. One patient in the drainage group developed an intra-abdominal abscess, but there was no significant difference between the two LC groups with respect to overall postoperative complication rate. ConclusionApplication of a peritoneal drainage tube after simple elective, uncomplicated LC did not provide any clinical benefit to the patients, and should be considered according to the operating physician′s judgment on a case-by-case basis.

  14. A Theoretical Study of Subsurface Drainage Model Simulation of ...

    A Theoretical Study of Subsurface Drainage Model Simulation of Drainage Flow and ... of subsurface drain spacing, evapotranspiration and irrigation water quality on ... The study was carried out on a conceptual uniform homogenous irrigated ...

  15. Streams and their future inhabitants

    Sand-Jensen, K.; Friberg, N.


    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?...

  16. The significance of avulsion phenomena in the alluvial filling configuration of a mountain stream: Venero Claro (Central Spain)

    Ruiz-Villanueva, V.; Díez-Herrero, A.; Bodoque, J. M.; Fernández-García, P.; Ballesteros, J. A.


    In the dynamics and evolution of large river floodplains, alluvial fans and debris cones, avulsion phenomena have been considered very important. However, traditionally, in mountain streams, avulsion phenomena have been underestimated because they are not very frequent, and usually they are restricted to little chute cut-off. Nevertheless, there are mountainous areas where the valley bottom gets wider, and the alluvial filling works like an elongated debris cone. The Cabrera Stream in the Venero Claro reach (Spanish Central System) is one of these special areas. In this case, avulsion phenomena took place triggered by flash floods, and they were usually associated with hyperconcentrated flows, which exceeded the upper level of levees and banks, redefining the sedimentary architecture of the alluvial filling. In this study, an analysis of geomorphologic and sedymentological evolution of the alluvial filling in Venero Claro have been carried out. On this way, cartography made from the 19th Century until ninety ages were compared, and a stereoscopic analysis of aerial photographs and digital ortoimages were applied. Furthermore, the sedimentary filling was studied applying classic sedimentological techniques, such as a description and interpretation of sedimentary structures and facies analysis at field. As a result of the geomorphologic evolution analysis, a straightforward evolution model is proposed. This model enhances the relevant importance of the avulsion phenomena in the geomorphologic configuration of the Cabrera Stream in the Venero Claro reach. From the river pattern point of view, the avulsion phenomena originate capture processes in the main stream and its tributaries. As a result of these processes, the drainage network pattern changes successively from dendritic to sub-parallel. On other hand, from the sedimentologic point of view, the stratigraphy is composed of channel facies (debris flow facies and fluvial-torrential gravelbars) and back

  17. Mining Building Metadata by Data Stream Comparison

    Holmegaard, Emil; Kjærgaard, Mikkel Baun


    to handle data streams with only slightly similar patterns. We have evaluated Metafier with points and data from one building located in Denmark. We have evaluated Metafier with 903 points, and the overall accuracy, with only 3 known examples, was 94.71%. Furthermore we found that using DTW for mining...... ways to annotate sensor and actuation points. This makes it difficult to create intuitive queries for retrieving data streams from points. Another problem is the amount of insufficient or missing metadata. We introduce Metafier, a tool for extracting metadata from comparing data streams. Metafier...... enables a semi-automatic labeling of metadata to building instrumentation. Metafier annotates points with metadata by comparing the data from a set of validated points with unvalidated points. Metafier has three different algorithms to compare points with based on their data. The three algorithms...

  18. Mining Building Metadata by Data Stream Comparison

    Holmegaard, Emil; Kjærgaard, Mikkel Baun


    to handle data streams with only slightly similar patterns. We have evaluated Metafier with points and data from one building located in Denmark. We have evaluated Metafier with 903 points, and the overall accuracy, with only 3 known examples, was 94.71%. Furthermore we found that using DTW for mining...... ways to annotate sensor and actuation points. This makes it difficult to create intuitive queries for retrieving data streams from points. Another problem is the amount of insufficient or missing metadata. We introduce Metafier, a tool for extracting metadata from comparing data streams. Metafier...... enables a semi-automatic labeling of metadata to building instrumentation. Metafier annotates points with metadata by comparing the data from a set of validated points with unvalidated points. Metafier has three different algorithms to compare points with based on their data. The three algorithms...

  19. Online Visual Analytics of Text Streams.

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


    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.

  20. Equations for estimating bankfull channel geometry and discharge for streams in Massachusetts

    Bent, Gardner C.; Waite, Andrew M.


    Regression equations were developed for estimating bankfull geometry—width, mean depth, cross-sectional area—and discharge for streams in Massachusetts. The equations provide water-resource and conservation managers with methods for estimating bankfull characteristics at specific stream sites in Massachusetts. This information can be used for the adminstration of the Commonwealth of Massachusetts Rivers Protection Act of 1996, which establishes a protected riverfront area extending from the mean annual high-water line corresponding to the elevation of bankfull discharge along each side of a perennial stream. Additionally, information on bankfull channel geometry and discharge are important to Federal, State, and local government agencies and private organizations involved in stream assessment and restoration projects. Regression equations are based on data from stream surveys at 33 sites (32 streamgages and 1 crest-stage gage operated by the U.S. Geological Survey) in and near Massachusetts. Drainage areas of the 33 sites ranged from 0.60 to 329 square miles (mi2). At 27 of the 33 sites, field data were collected and analyses were done to determine bankfull channel geometry and discharge as part of the present study. For 6 of the 33 sites, data on bankfull channel geometry and discharge were compiled from other studies done by the U.S. Geological Survey, Natural Resources Conservation Service of the U.S. Department of Agriculture, and the Vermont Department of Environmental Conservation. Similar techniques were used for field data collection and analysis for bankfull channel geometry and discharge at all 33 sites. Recurrence intervals of the bankfull discharge, which represent the frequency with which a stream fills its channel, averaged 1.53 years (median value 1.34 years) at the 33 sites. Simple regression equations were developed for bankfull width, mean depth, cross-sectional area, and discharge using drainage area, which is the most significant explanatory

  1. 46 CFR 178.420 - Drainage of cockpit vessels.


    ... 46 Shipping 7 2010-10-01 2010-10-01 false Drainage of cockpit vessels. 178.420 Section 178.420... TONS) INTACT STABILITY AND SEAWORTHINESS Drainage of Weather Decks § 178.420 Drainage of cockpit vessels. (a) Except as follows, the cockpit on a cockpit vessel may be watertight: (1) A cockpit may...

  2. Influence of catchment land cover on stoichiometry and stable isotope compositions of basal resources and macroinvertebrate consumers in headwater streams

    Anthropogenic land use affects aquatic landscapes. For example, landscape-level conversion to urban or agricultural land can heavily influence nutrient cycles in headwater streams via increased nutrient loading and altered hydrologic patterns. Recent studies in headwater streams ...

  3. Influence of catchment land cover on stoichiometry and stable isotope compositions of basal resources and macroinvertebrate consumers in headwater streams

    Anthropogenic land use affects aquatic landscapes. For example, landscape-level conversion to urban or agricultural land can heavily influence nutrient cycles in headwater streams via increased nutrient loading and altered hydrologic patterns. Recent studies in headwater streams ...


    Kiran, V.; Dr. Bhimasen .S; E. Mastanaiah; A. Thiruppathi


    Background: Patients with COPD will have more amount of secretions. To clear the secretions by using of different bronchial hygiene techniques like postural drainage and autogenic drainage technique, manual hyperventilation technique ,active cycle breathing technique .Hence in this study to compare the short-term effects of postural drainage with clapping (PD) and autogenic drainage (AD) on level of oxygen saturation in blood, and amount of sputum recovery. Methodology: The study was done ...

  5. Study of water quality using benthic biological indicators in rural and urban streams

    Sandro Morais Pimenta


    Full Text Available Methods other than physical-chemical and geochemical analyses can be used to assess water quality in surface drainage. This study used intolerant, tolerant and resistant benthic species as bioindicators of changes in water quality of two streams, taking in account particle size of sediments and volatile solids. Eight points were sampled in the stream Bandeirinha and four points in the stream Josefa Gomes in January and September 2013 in the municipality of Formosa-GO. The two streams were chosen in order to study two different environments. The study used the diversity indexes of Shannon (H, Equitability (E and Bray-Curtis Similarity and the grouping analysis method UPGMA (Unweighted Pair Group Method with Arithmetic Mean. The results of particle size and volatile solids study of Bandeirinha stream located in rural areas showed bioindicator species intolerant of changes in water quality. The stream Josefa Gomes, completely inserted in an urban environment, showed alteration identified by tolerant and resistant species. The results demonstrate differences in water quality in the rural and urban environments and the relationship of bioindicators with sediments. The study aids the interpretation of changes in the water quality of the two drainages areas. Analysis of water quality based upon benthic biological indicators associated with physical-chemical and geochemical analyses of water and sediments provide a better interpretation of the results.

  6. The results of the electrochemical clearning of drainage waters

    Kabannik, Vasilina; Saeva, Olga


    There is a problem of industrial drains clearing in various branches, but especially sharply in a metal manufacture that is caused by great volumes of the wastewater containing high residual concentration of heavy metals. It is necessary to pay attention to solids in wastes. In a long-term interaction with oxygen of air and natural deposits the acid drainage is often formed and takes out a number of elements with different classes of toxicity to superficial and underground waters. Therefore search of an extraction possibilities for toxic components for a eliminate of their further migration is the big deal. Belov Zink Plant located in the Kemerovo region. During sixty years the factory stably made up to 10 000 tons of zinc annually and in passing up to 30 000 tons H2SO4 processing a blende concentrate. Now the factory has stopped the activity, however, in territory have remained uncontrolledly stored about one million tons of the wastes, presented by slags and ashes. Visually clinker represent coarse-grained sands of the typical slag containing 0.7-15% Zn, 0.3-8.5% Cu, 0.03-0.7% Pb and 2-400 g/t Cd. Besides in tailings the sub-standard sulfuric acid [Bortnikova, etc., 2006] are merged. Acid (рН=3.5) and highsaline waters of a drainage stream with significant concentration sulfate-ion (up to 20 g/l), copper (up to 6 g/l) and zinc (up to 4 g/l), that allows to consider as macrocomponents. A wide number of microcells in drains exceeds maximum concentration limit (MPC) of chemical substances in objects of drinking and community use. The basic chemical forms of present metals (Al, Mn, Zn, Fe, Co, Ni, Pb, Cu) are aquo-ions and sulphatic complexes. Earlier in our laboratory searching of a way of a toxic components concentration downturn in drains of Belov plant - sorptive clearing by natural clays [Gaskova, Kabannik, 2009] and sedimentation of toxic elements on carbonate barrier [Yurkevich, etc., 2008] were done, however the desirable result by virtue of that this

  7. Chronic and episodic acidification of Adirondack streams from acid rain in 2003-2005

    Lawrence, G.B.; Roy, K.M.; Baldigo, Barry P.; Simonin, H.A.; Capone, S.B.; Sutherland, J.W.; Nierzwicki-Bauer, S. A.; Boylen, C.W.


    Limited information is available on streams in the Adirondack region of New York, although streams are more prone to acidification than the more studied Adirondack lakes. A stream assessment was therefore undertaken in the Oswegatchie and Black River drainages; an area of 4585 km2 in the western part of the Adirondack region. Acidification was evaluated with the newly developed base-cation surplus (BCS) and the conventional acid-neutralizing capacity by Gran titration (ANCG). During the survey when stream water was most acidic (March 2004), 105 of 188 streams (56%) were acidified based on the criterion of BCS acidic (August 2003), 15 of 129 streams (12%) were acidified based on the criterion of BCS acidic deposition to stream acidification was greater than that of strongly acidic organic acids in each of the surveys by factors ranging from approximately 2 to 5, but was greatest during spring snowmelt and least during elevated base flow in August. During snowmelt, the percentage attributable to acidic deposition was 81%, whereas during the October 2003 survey, when dissolved organic carbon (DOC) concentrations were highest, this percentage was 66%. The total length of stream reaches estimated to be prone to acidification was 718 km out of a total of 1237 km of stream reaches that were assessed. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  8. Biological and Physical Inventory of the Streams within the Nez Perce Reservation; Synopsis, 1982-1984 Final Report.

    Fuller, Ross K.; Kucera, P.A.; Johnson, D.B. (Nez Perce Tribe, Lapwai, ID)


    This report provides a synopsis for three years of inventory work on the streams in the Lower Clearwater Basin, Idaho. The main emphasis of the study was to document which streams presently support anadromous salmonids, the extent of production in those streams and the identification of those streams which may best respond to enhancement restoration activities. Rainbow-steelhead trout (Salmo gairdneri) were the most abundant anadromous salmonid found. Chinook salmon (Oncorhynchus tshawytscha) were found rarely except in the Lolo Creek Drainage. The main environmental problem affecting these streams was the extreme flow variations which commonly occur. This is due primarily to poor land management practices. Enhancement recommendations are suggested for these streams which include passage around barriers, barrier removal, riparian enhancement, instream habitat improvement, and better land use practices.

  9. Montana StreamStats—A method for retrieving basin and streamflow characteristics in Montana: Chapter A in Montana StreamStats

    McCarthy, Peter M.; Dutton, DeAnn M.; Sando, Steven K.; Sando, Roy


    The U.S. Geological Survey (USGS) provides streamflow characteristics and other related information needed by water-resource managers to protect people and property from floods, plan and manage water-resource activities, and protect water quality. Streamflow characteristics provided by the USGS, such as peak-flow and low-flow frequencies for streamflow-gaging stations, are frequently used by engineers, flood forecasters, land managers, biologists, and others to guide their everyday decisions. In addition to providing streamflow characteristics at streamflow-gaging stations, the USGS also develops regional regression equations and drainage area-adjustment methods for estimating streamflow characteristics at locations on ungaged streams. Regional regression equations can be complex and often require users to determine several basin characteristics, which are physical and climatic characteristics of the stream and its drainage basin. Obtaining these basin characteristics for streamflow-gaging stations and ungaged sites traditionally has been time consuming and subjective, and led to inconsistent results.StreamStats is a Web-based geographic information system application that was created by the USGS to provide users with access to an assortment of analytical tools that are useful for water-resource planning and management. StreamStats allows users to easily obtain streamflow and basin characteristics for USGS streamflow-gaging stations and user-selected locations on ungaged streams. The USGS, in cooperation with Montana Department of Transportation, Montana Department of Environmental Quality, and Montana Department of Natural Resources and Conservation, completed a study to develop a StreamStats application for Montana, compute streamflow characteristics at streamflow-gaging stations, and develop regional regression equations to estimate streamflow characteristics at ungaged sites. Chapter A of this Scientific Investigations Report describes the Montana Stream

  10. Introduction to Tidal Streams

    Newberg, Heidi Jo

    Dwarf galaxies that come too close to larger galaxies suffer tidal disruption; the differential gravitational force between one side of the galaxy and the other serves to rip the stars from the dwarf galaxy so that they instead orbit the larger galaxy. This process produces "tidal streams" of stars, which can be found in the stellar halo of the Milky Way, as well as in halos of other galaxies. This chapter provides a general introduction to tidal streams, including the mechanism through which the streams are created, the history of how they were discovered, and the observational techniques by which they can be detected. In addition, their use in unraveling galaxy formation histories and the distribution of dark matter in galaxies is discussed, as is the interaction between these dwarf galaxy satellites and the disk of the larger galaxy.

  11. Numerical simulation of transient flow in horizontal drainage systems

    Ze-yu MAO; Han XIAO; Ying LIU; Ying-jun HU


    A numerical simulation model based on the characteristic-based finite-difference method with a time-line interpolation scheme was developed for predicting transient free surface flow in horizontal drainage systems. The fundamental accuracy of the numerical model was first clarified by comparison with the experimental results for a single drainage pipe. Boundary conditions for junctions and bends, which are often encountered in drainage systems, were studied both experimentally and numerically. The numerical model was applied to an actual drainage system. Comparison with a full-scale model experiment indicates that the model can be used to accurately predict flow characteristics in actual drainage networks.

  12. Thermokarst lakes, drainage, and drained basins

    Grosse, G.; Jones, B.; Arp, C.; Shroder, John F.


    Thermokarst lakes and drained lake basins are widespread in Arctic and sub-Arctic permafrost lowlands with ice-rich sediments. Thermokarst lake formation is a dominant mode of permafrost degradation and is linked to surface disturbance, subsequent melting of ground ice, surface subsidence, water impoundment, and positive feedbacks between lake growth and permafrost thaw, whereas lake drainage generally results in local permafrost aggradation. Thermokarst lakes characteristically have unique limnological, morphological, and biogeochemical characteristics that are closely tied to cold-climate conditions and permafrost properties. Thermokarst lakes also have a tendency toward complete or partial drainage through permafrost degradation and erosion. Thermokarst lake dynamics strongly affect the development of landscape geomorphology, hydrology, and the habitat characteristic of permafrost lowlands.

  13. Autogenic drainage: efficacy of a simplified method.

    Lindemann, H; Boldt, A; Kieselmann, R


    A simplified and modified technique of the original autogenic drainage (AD) is described which is supplemented by breathing against an external flow resistance. The new method allows a better teaching and learning. It's efficacy is proven by means of a comparative trial of AD and PEP physiotherapy (i.e. expiration against a defined stenosis). The autogenic drainage (AD) was introduced by a Belgian working group (2). The basic idea was to support the elimination of mucus by deep breathing and by repressing the cough as long as possible. However, a rather sophisticated method impeded teaching and learning of AD (1). Thus, till now, there are only preliminary results which suggest the efficacy of AD (e.g. 3). Therefore, a simplified technique was developed and examined with regard to its sputum eliminating effect.

  14. Range of drainage effect of surface mines

    Sozanski, J.


    This paper discusses methods of calculating the range of effects of water drainage from surface coal mines and other surface mines. It is suggested that methods based on test pumping (water drainage) are time consuming, and the results can be distorted by atmospheric factors such as rain fall or dry period. So-called empirical formulae produce results which are often incorrect. The size of a cone shaped depression calculated on the basis of empirical formulae can be ten times smaller than the size of the real depression. It is suggested that using a formula based on the Dupuit formula is superior to other methods of depression calculation. According to the derived formulae the radius of the depresion cone is a function of parameters of the water bearing horizons, size of surface mine working and of water depression. The proposed formula also takes into account the influence of atmospheric factors (water influx caused by precipitation, etc.). (1 ref.) (In Polish)

  15. Activity of microorganisms in acid mine water. I. Influence of acid water on aerobic heterotrophs of a normal stream.

    Tuttle, J H; Randles, C I; Dugan, P R


    Comparison of microbial content of acid-contaminated and nonacid-contaminated streams from the same geographical area indicated that nonacid streams contained relatively low numbers of acid-tolerant heterotrophic microorganisms. The acid-tolerant aerobes survived when acid entered the stream and actually increased in number to about 2 x 10(3) per ml until the pH approached 3.0. The organisms then represented the heterotrophic aerobic microflora of the streams comprised of a mixture of mine drainage and nonacid water. A stream which was entirely acid drainage did not have a similar microflora. Most gram-positive aerobic and anaerobic bacteria died out very rapidly in acidic water, and they comprised a very small percentage of the microbial population of the streams examined. Iron- and sulfur-oxidizing autotrophic bacteria were present wherever mine water entered a stream system. The sulfur-oxidizing bacteria predominated over iron oxidizers. Ecological data from the field were verified by laboratory experiments designed to simulate stream conditions.

  16. Urban drainage models - making uncertainty analysis simple

    Vezzaro, Luca; Mikkelsen, Peter Steen; Deletic, Ana;


    There is increasing awareness about uncertainties in modelling of urban drainage systems and, as such, many new methods for uncertainty analyses have been developed. Despite this, all available methods have limitations which restrict their widespread application among practitioners. Here, a modif...... probability distributions (often used for sensitivity analyses) and prediction intervals. To demonstrate the new method, it is applied to a conceptual rainfall-runoff model using a dataset collected from Melbourne, Australia....

  17. Factors influencing pleural drainage in parapneumonic effusions.

    Porcel, J M; Valencia, H; Bielsa, S


    The identification of parapneumonic effusions (PPE) requiring pleural drainage is challenging. We aimed to determine the diagnostic accuracy of radiological and pleural fluid findings in discriminating between PPE that need drainage (complicated PPE (CPPE)) and those that could be resolved with antibiotics only (uncomplicated PPE (UPPE)). A retrospective review of 641 consecutive PPE, of which 393 were categorized as CPPE and 248 as UPPE. Demographics, radiological (size and laterality on a chest radiograph) and pleural fluid parameters (pus, bacterial cultures, biochemistries) were compared among groups. Logistic regression was performed to determine variables useful for predicting chest drainage, and receiver-operating characteristic curves assisted in the selection of the best cutoff values. According to the likelihood ratios (LR), findings increasing the probability of chest tube usage the most were: effusions occupying ≥1/2 of the hemithorax (LR 13.5), pleural fluid pH ≤7.15 (LR 6.2), pleural fluid glucose ≤40mg/dL (LR 5.6), pus (LR 4.8), positive pleural fluid cultures (LR 3.6), and pleural fluid lactate dehydrogenase >2000U/L (LR 3.4). In the logistic regression analysis only the first two were selected as significant predictors of CPPE. In non-purulent effusions, the effusion's size and pleural fluid pH retained their discriminatory properties, in addition to a pleural fluid C-reactive protein (CRP) level >100mg/L. Large radiological effusions and a pleural fluid pH ≤7.15 were the best predictors for chest drainage in patients with PPE. In the subgroup of patients with non-purulent effusions, pleural fluid CRP also contributed to CPPE identification. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  18. Fire history of southeastern Glacier National Park: Missouri River Drainage

    Barrett, Stephen W.


    In 1982, Glacier National Park (GNP) initiated long-term studies to document the fire history of all forested lands in the 410,000 ha. park. To date, studies have been conducted for GNP west of the Continental Divide (Barrett et al. 1991), roughly half of the total park area. These and other fire history studies in the Northern Rockies (Arno 1976, Sneck 1977, Arno 1980, Romme 1982, Romme and Despain 1989, Barrett and Arno 1991, Barrett 1993a, Barrett 1993b) have shown that fire history data can be an integral element of fire management planning, particularly wen natiral fire plans are being developed for parks and wilderness. The value of site specific fire history data is apparent when considering study results for lodgepole pin (Pinus contorta var. latifolia) forests. Lodgepole pine is a major subalpine type in the Northern Rockies and such stands experiences a wide range of presettlement fire patterns. On relatively warm-dry sites at lower elevations, such as in GNP's North Fork drainage (Barrett et al. 1991), short to moderately long interval (25-150 yr) fires occurred in a mixed severity pattern ranging from non-lethal underburns to total stand replacement (Arno 1976, Sneck 1977, Barrett and Arno 1991). Markedly different fire history occurred at high elevation lodgepole pine stands on highly unproductive sites, such as on Yellowstone National Park's (YNP) subalpine plateau. Romme (1982) found that, on some sites, stand replacing fires recurred after very long intervals (300-400 yr), and that non-lethal surface fires were rare. For somewhat more productive sites in the Absaroka Mountains in YNP, Barrett (1993a) estimated a 200 year mean replacement interval, in a pattern similar to that found in steep mountain terrain elsewhere, such as in the Middle Fork Flathead River drainage (Barrett et al. 1991, Sneck 1977). Aside from post-1900 written records (ayres 1900; fire atlas data on file, GNP Archives Div. and GNP Resources Mgt. Div.), little fire history

  19. Drainage and Stratification Kinetics of Foam Films

    Zhang, Yiran; Sharma, Vivek


    Baking bread, brewing cappuccino, pouring beer, washing dishes, shaving, shampooing, whipping eggs and blowing bubbles all involve creation of aqueous foam films. Foam lifetime, drainage kinetics and stability are strongly influenced by surfactant type (ionic vs non-ionic), and added proteins, particles or polymers modify typical responses. The rate at which fluid drains out from a foam film, i.e. drainage kinetics, is determined in the last stages primarily by molecular interactions and capillarity. Interestingly, for certain low molecular weight surfactants, colloids and polyelectrolyte-surfactant mixtures, a layered ordering of molecules, micelles or particles inside the foam films leads to a stepwise thinning phenomena called stratification. Though stratification is observed in many confined systems including foam films containing particles or polyelectrolytes, films containing globular proteins seem not to show this behavior. Using a Scheludko-type cell, we experimentally study the drainage and stratification kinetics of horizontal foam films formed by protein-surfactant mixtures, and carefully determine how the presence of proteins influences the hydrodynamics and thermodynamics of foam films.

  20. Drawdown behavior of gravity drainage wells

    Aasen, J.A.; Ramey, H.J. Jr.


    An analytical solution for drawdown in gravity drainage wells is developed. The free-surface flow is viewed as incompressible, and anisotropy effects are included. The well is a line source well, and the reservoir is infinitely large. The model is valid for small drawdowns. The uniform wellbore potential inner boundary condition is modelled using the proper Green`s function. The discontinuity at the wellbore is solved by introducing a finite skin radius, and the formulation produces a seepage face. The calculated wellbore flux distribution and wellbore pressures are in fair agreement with results obtained using a numerical gravity drainage simulator. Three distinct flow periods are observed. The wellbore storage period is caused by the moving liquid level, and the duration is short. During the long intermediate flow period, the wellbore pressure is nearly constant. In this period the free surface moves downwards, and the liquid is produced mainly by vertical drainage. At long times the semilog straight line appears. The confined liquid solutions by Theis (1935) and van Everdingen and Hurst (1949) may be used during the pseudoradial flow period if the flowrate is low. New type curves are presented that yield both vertical and horizontal permeabilities.

  1. The water quality of streams draining a plantation forest on gley soils: the Nant Tanllwyth, Plynlimon mid-Wales

    C. Neal


    Full Text Available The water quality of the Nant Tanllwyth stream in the Plynlimon region of mid-Wales is related to the key hydrobiogeological controls and the effects of conifer harvesting based on an analysis of rain, cloud, stream and groundwater measurements. The results show the normal patterns of stream water quality response to hydrology. Thus, there is a high damping of atmospheric inputs due to storage in a highly heterogeneous soil and groundwater system. Correspondingly, there is a highly dynamic response for components such as calcium, bicarbonate and aluminium. This response links to the relative inputs of acidic and aluminium-bearing soil waters under high flow conditions and base enriched bicarbonate bearing waters from the groundwater areas under baseflow conditions. The introduction of a deep borehole near the main stem of the river opened up a groundwater flow route to the stream and other parts of the catchment. There were two aspects to this. Firstly, it caused a change to the stream water quality, particularly under baseflow conditions, by increasing the concentrations of calcium and magnesium and by reducing the acidity. The monitoring shows that this change has persisted for over eight years and that there is no sign of reversion to pre-borehole times. Secondly, it caused a change in the groundwater level and chemistry at a borehole on the other side of the river. This feature shows that the fracture system is of hydrogeochemical and hydrogeological complexity. The effects of conifer harvesting are remarkable. At the local scale, felling leads to the expected short term increase in nitrate, ammonium and phosphate from the disturbance of the soil and the reduction in uptake into the vegetation. Correspondingly, there is a reduction in sodium and chloride linked to reduced scavenging of atmospheric inputs from cloud water by the vegetation and also due to increased dilution potential due to reductions in transpiration by the trees. However

  2. Treatment of severe acute pancreatitis through retroperitoneal laparoscopic drainage

    Chun Tang; Baolin Wang; Bing Xie; Hongming Liu; Ping Chen


    A treatment method based on drainage via retroperitoneal laparoscopy was adopted for 15 severe acute pancreatitis (SAP) patients to investigate the feasibility of the method.Ten patients received only drainage via retroperitoneai laparoscopy,four patients received drainage via both retroperitoneal and preperitoneal laparoscopy,and one patient received drainage via conversion to laparotomy.Thirteen patients exhibited a good drainage effect and were successfully cured without any other surgical treatment.Two patients had encapsulated effusions or pancreatic pseudocysts after surgery,but were successfully cured after lavage and B ultrasound-guided percutaneous catheter drainage.SAP treatment via retroperitoneal laparoscopic drainage is an effective surgical method,resulting in minor injury.

  3. Comparison of animated jet stream visualizations

    Nocke, Thomas; Hoffmann, Peter


    The visualization of 3D atmospheric phenomena in space and time is still a challenging problem. In particular, multiple solutions of animated jet stream visualizations have been produced in recent years, which were designed to visually analyze and communicate the jet and related impacts on weather circulation patterns and extreme weather events. This PICO integrates popular and new jet animation solutions and inter-compares them. The applied techniques (e.g. stream lines or line integral convolution) and parametrizations (color mapping, line lengths) are discussed with respect to visualization quality criteria and their suitability for certain visualization tasks (e.g. jet patterns and jet anomaly analysis, communicating its relevance for climate change).

  4. Preoperative biliary drainage for periampullary tumors causing obstructive jaundice; DRainage vs. (direct OPeration (DROP-trial

    Sosef Meindert N


    Full Text Available Abstract Background Surgery in patients with obstructive jaundice caused by a periampullary (pancreas, papilla, distal bile duct tumor is associated with a higher risk of postoperative complications than in non-jaundiced patients. Preoperative biliary drainage was introduced in an attempt to improve the general condition and thus reduce postoperative morbidity and mortality. Early studies showed a reduction in morbidity. However, more recently the focus has shifted towards the negative effects of drainage, such as an increase of infectious complications. Whether biliary drainage should always be performed in jaundiced patients remains controversial. The randomized controlled multicenter DROP-trial (DRainage vs. Operation was conceived to compare the outcome of a 'preoperative biliary drainage strategy' (standard strategy with that of an 'early-surgery' strategy, with respect to the incidence of severe complications (primary-outcome measure, hospital stay, number of invasive diagnostic tests, costs, and quality of life. Methods/design Patients with obstructive jaundice due to a periampullary tumor, eligible for exploration after staging with CT scan, and scheduled to undergo a "curative" resection, will be randomized to either "early surgical treatment" (within one week or "preoperative biliary drainage" (for 4 weeks and subsequent surgical treatment (standard treatment. Primary outcome measure is the percentage of severe complications up to 90 days after surgery. The sample size calculation is based on the equivalence design for the primary outcome measure. If equivalence is found, the comparison of the secondary outcomes will be essential in selecting the preferred strategy. Based on a 40% complication rate for early surgical treatment and 48% for preoperative drainage, equivalence is taken to be demonstrated if the percentage of severe complications with early surgical treatment is not more than 10% higher compared to standard treatment

  5. Closed suction drainage versus closed simple drainage in the management of modified radical mastectomy wounds.

    Ezeome, E R; Adebamowo, C A


    To compare the outcomes of modified radical mastectomy wounds managed by closed wound drainage with suction and without suction. A prospective randomised trial was conducted at the University College Hospital in Ibadan, and the University of Nigeria Teaching Hospital in Enugu. Fifty women who required modified radical mastectomy for breast cancer were randomised to have closed wound drainage with suction (26 patients) and closed wound drainage without suction (24 patients). There was no significant difference in the intraoperative and postoperative variables. Suction drainage drained less volume of fluid and stayed for a shorter time in the wound, but the differences were not significant. There was no difference in the length of hospital stay, time to stitch removal, and number of dressing changes. More haematomas and wound infections occurred in the simple drain group while more seromas occurred in the suction drain group, but these were not significant. The suction drain was more difficult to manage and the cost was 15 times higher than the simple drainage system. Closed simple drains are not inferior to suction drains in mastectomy wounds and, considering the cost saving and simplicity of postoperative care, they are preferable to suction drains.

  6. Regional and local scale modeling of stream temperatures and spatio-temporal variation in thermal sensitivities.

    Hilderbrand, Robert H; Kashiwagi, Michael T; Prochaska, Anthony P


    Understanding variation in stream thermal regimes becomes increasingly important as the climate changes and aquatic biota approach their thermal limits. We used data from paired air and water temperature loggers to develop region-scale and stream-specific models of average daily water temperature and to explore thermal sensitivities, the slopes of air-water temperature regressions, of mostly forested streams across Maryland, USA. The region-scale stream temperature model explained nearly 90 % of the variation (root mean square error = 0.957 °C), with the mostly flat coastal plain streams having significantly higher thermal sensitivities than the steeper highlands streams with piedmont streams intermediate. Model R (2) for stream-specific models was positively related to a stream's thermal sensitivity. Both the regional and the stream-specific air-water temperature regression models benefited from including mean daily discharge from regional gaging stations, but the degree of improvement declined as a stream's thermal sensitivity increased. Although catchment size had no relationship to thermal sensitivity, steeper streams or those with greater amounts of forest in their upstream watershed were less thermally sensitive. The subset of streams with three or more summers of temperature data exhibited a wide range of annual variation in thermal sensitivity at a site, with the variation not attributable to discharge, precipitation patterns, or physical attributes of streams or their watersheds. Our findings are a useful starting point to better understand patterns in stream thermal regimes. However, a more spatially and temporally comprehensive monitoring network should increase understanding of stream temperature variation and its controls as climatic patterns change.

  7. Parameterizing sub-surface drainage with geology to improve modeling streamflow responses to climate in data limited environments

    C. L. Tague


    Full Text Available Hydrologic models are one of the core tools used to project how water resources may change under a warming climate. These models are typically applied over a range of scales, from headwater streams to higher order rivers, and for a variety of purposes, such as evaluating changes to aquatic habitat or reservoir operation. Most hydrologic models require streamflow data to calibrate subsurface drainage parameters. In many cases, long-term gage records may not be available for calibration, particularly when assessments are focused on low-order stream reaches. Consequently, hydrologic modeling of climate change impacts is often performed in the absence of sufficient data to fully parameterize these hydrologic models. In this paper, we assess a geologic-based strategy for assigning drainage parameters. We examine the performance of this modeling strategy for the McKenzie River watershed in the US Oregon Cascades, a region where previous work has demonstrated sharp contrasts in hydrology based primarily on geological differences between the High and Western Cascades. Based on calibration and verification using existing streamflow data, we demonstrate that: (1 a set of streams ranging from 1st to 3rd order within the Western Cascade geologic region can share the same drainage parameter set, while (2 streams from the High Cascade geologic region require a different parameter set. Further, we show that a watershed comprised of a mixture of High and Western Cascade geologies can be modeled without additional calibration by transferring parameters from these distinctive High and Western Cascade end-member parameter sets. More generally, we show that by defining a set of end-member parameters that reflect different geologic classes, we can more efficiently apply a hydrologic model over a geologically complex landscape and resolve geo-climatic differences in how different watersheds are likely to respond to simple warming scenarios.

  8. A Survey of latest Algorithms for Frequent Itemset Mining in Data Stream



    Full Text Available Association rule mining and finding frequent patterns in data base has been a very old topic. With the advent of Big Data, the need for stream mining has increased. Hence the paper surveys various latest frequent pattern mining algorithms on data streams to understand various problems to be solved, their short comings and advantages over others.

  9. VAST Challenge 2016: Streaming Visual Analytics


    CO2 component and introduced our own fictitious gas called Hazium, which had unspecified hazardous effects on people. To create the occupancy...Check the data streams periodically as needed to ensure your software is working as expected and you are able to identify patterns of interest. Capture ...effective use of external data about normal CO2 levels, and provided a common-sense analysis that earned them an honorable mention in Effective

  10. River Mileages and Drainage Areas for Illinois Streams. Volume 1. Illinois Except Illinois River Basin.



  11. River Mileages and Drainage Areas for Illinois Streams. Volume 2. Illinois River Basin.



  12. An ecotoxicological screening tool to prioritise acid mine drainage impacted streams for future restoration

    Oberholster, Paul J


    Full Text Available of young for a test, adult females bearing embryos in their brood pouches were 235 removed from the stock cultures 24 hours prior to the initiation of the test, and placed in 236 beakers containing moderately hard water (Oberholster et al., 2005) and food.... magna cultured water (total volume 150 ml-1). A total of 30 240 organisms per sample were used in the test (1 set of 3 beakers each for 100 % sample 241 concentration, and 1 set of 3 control beakers). 242 243 In the case of the D. magna 48 hour...

  13. Ohio-drainage stream centerline coverage for use with Water Resources Investigations Report 03-4164

    U.S. Geological Survey, Department of the Interior — This vector coverage of hydrography centerlines was derived from the National Hydrography Dataset (NHD), and encompasses all of Ohio and portions of Indiana,...

  14. Drainage areas for selected stream-sampling stations, Missouri River Basin

    U.S. Geological Survey, Department of the Interior — As part of the U.S. Geological Survey's (USGS) National Water-Quality Assessment Program (NAWQA), an investigation of the Missouri River Basin is being conducted to...

  15. Factors of Stream Instability in Urban Centres of Southern Nigeria: Case Study of Port Harcourt City River Systems.

    Amangabara, G. T.


    There are two main drainage rivers in the Port Harcourt Metropolis - The Ntamogba and the Woji creek (Abam, 2004). There are a few other drainage rivers that are equally important e.g. the Nwaja River that drains Rumukalagbor, Elekahia, New GRA Phases IV and V, Presidential Housing Estate and Sun Ray publications Area of Aba Road. These river systems drain the entire Port Harcourt City dividing the City into three major drainage zones. Since the discovery of oil in Nigeria in the 1950s, the country has been suffering the negative environmental consequences of oil development. The growth of the country's oil industry, combined with population explosion and a lack of environmental regulations, led to substantial damage to Nigeria's environment, especially in the Niger Delta region, the center of the country's oil industry. Uncontrolled population movement as well as spontaneous housing development on marginal lands such as stream corridors, has led to the degradation of all major stream channels in the Nation's oil capital - Port Harcourt City. The longitudinal profiles and cross sections of reaches of three major streams (Ntamogba, Nwaja, and Oginigba streams) were investigated. Land use maps of 1979 1999 and 2004 were used. Our result showed that 1). Almost all of the stream corridors have been built up without adequate plan 2). The natural grades have been distorted by channelisation for the purpose of flood evacuation without geomorphic consideration .3). Our research also shows that the interface of saline water and fresh water has extended upstream affecting urban infrastructure. 4) localized damming and sedimentation behind hydraulic structures were common occurrences) our overall result indicate that two episodes of channel incision on Oginigba stream had increased slope reduced sinuosity increased entrenchment and reduce width-depth ratio . Conclusively the factors of the instability of theses urban streams are manly the processes of urbanization which

  16. Numerical Modelling of Streams

    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...

  17. Academic streaming in Europe

    Falaschi, Alessandro; Mønster, Dan; Doležal, Ivan


    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...

  18. Music Streaming in 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...

  19. The Rabbit Stream Cipher

    Boesgaard, Martin; Vesterager, Mette; Zenner, Erik


    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....

  20. Stream Automata Are Coalgebras

    Ciancia, V.; Venema, Y.


    Stream automata (also called ω-automata) and ω-regular languages are of paramount importance in Computer Science and Logic. A coalgebraic treatment of these structures has not been given yet. We study a simple two-sorted setting where deterministic Muller automata can be cast as coalgebras, so that

  1. Stream Water Quality Model

    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).

  2. Clustering Text Data Streams

    Yu-Bao Liu; Jia-Rong Cai; Jian Yin; Ada Wai-Chee Fu


    Clustering text data streams is an important issue in data mining community and has a number of applications such as news group filtering, text crawling, document organization and topic detection and tracing etc. However, most methods are similarity-based approaches and only use the TF*IDF scheme to represent the semantics of text data and often lead to poor clustering quality. Recently, researchers argue that semantic smoothing model is more efficient than the existing TF.IDF scheme for improving text clustering quality. However, the existing semantic smoothing model is not suitable for dynamic text data context. In this paper, we extend the semantic smoothing model into text data streams context firstly. Based on the extended model, we then present two online clustering algorithms OCTS and OCTSM for the clustering of massive text data streams. In both algorithms, we also present a new cluster statistics structure named cluster profile which can capture the semantics of text data streams dynamically and at the same time speed up the clustering process. Some efficient implementations for our algorithms are also given. Finally, we present a series of experimental results illustrating the effectiveness of our technique.

  3. Streaming-video produktion

    Grønkjær, Poul


     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....

  4. On Meteoroid Streams Identification

    Klacka, J


    Criterion for the membership of individual meteors to meteoroid streams presented by Valsecchi {\\it et. al.} (1999) and Jopek {\\it et. al.} (1999) is discussed. The authors characterize and use their criterion as a distance function. However, it is not a distance function. Some practical aspects are also discussed. Correct criterion is presented.

  5. Assessment of waterlogging in agricultural megaprojects in the closed drainage basins of the Western Desert of Egypt

    M. El Bastawesy


    Full Text Available This paper investigates the development of waterlogging in the cultivated and arable areas within typical dryland closed drainage basins (e.g. the Farafra and Baharia Oases, which are located in the Western Desert of Egypt. Multi-temporal remote sensing data of the Landsat Thematic Mapper (TM and Enhanced Thematic Mapper (ETM+ were collected and processed to detect the land cover changes; cultivations, and the extent of water ponds and seepage channels. The Shuttle Radar Topography Mission (SRTM digital elevation model (DEM has been processed to delineate the catchment morphometrical parameters (i.e. drainage networks, catchment divides and surface areas of different basins and to examine the spatial distribution of cultivated fields and their relation to the extracted drainage networks. The soil of these closed drainage basins is mainly shallow and lithic with high calcium carbonate content; therefore, the downward percolation of excess irrigation water is limited by the development of subsurface hardpan, which also saturates the upper layer of soil with water. The subsurface seepage from the newly cultivated areas in the Farafra Oasis has revealed the pattern of buried alluvial channels, which are waterlogged and outlined by the growth of diagnostic saline shrubs. Furthermore, the courses of these waterlogged channels are coinciding with their counterparts of the SRTM DEM, and the recent satellite images show that the surface playas in the downstream of these channels are partially occupied by water ponds. On the other hand, a large water pond has occupied the main playa and submerged the surrounding fields, as a large area has been cultivated within a relatively small closed drainage basin in the Baharia Oasis. The geomorphology of closed drainage basins has to be considered when planning for a new cultivation in dryland catchments to better control waterlogging hazards. The "dry-drainage" concept can be implemented as the drainage and

  6. Acid-stress effects on stream biology

    Herrmann, J. (Kalmar Univ. (Sweden). Dept. of Natural Sciences); Degerman, E. (Inst. of Freshwater Research, Drottningholm (Sweden)); Gerhardt, A. (Lund Univ. (Sweden). Dept. of Ecology); Johansson, Catarina (Statistics Sweden, Stockholm (Sweden)); Lingdell, P.E. (Gunilbo, Skinnskatteberg (Sweden)); Muniz, I. (Norvegian Inst. for Nature Research (NINA), Oslo (Norway))


    This paper reports and discusses the results of Swedish freshwater acidification research, for the period 1988.1993 and earlier. Changed biotic patterns are exemplified by increased occurrence of those green algae that indicate an increase in nutrients, reduced species richness of invertebrates, a general shift in proportion from invertebrate grazers towards shredders, decreasing populations of fish. Impact on birds appears less validated. The mechanisms for the changes in individual, population and community levels include elevated hydrogen, aluminium and cadmium concentrations that affect ion balance and respiration in fish and invertebrates, but also various behavior patterns, and development stages. Al can ameliorate low pH temporarily but does not biomagnify along food chains, and neither predatory insects nor flycatchers seem to accumulate Al. Iron precipitation can affect feeding ability and respiration of mayfly nymphs. That humic substances may mitigate metals still seems uncertain for fish and invertebrates. Generally, most changes in the biotic patterns of streams seem to be related to abiotic impact routes. Relevant and sufficient knowledge seems to be lacking in three research fields of acidification impact on streams; viz. increasing occurrence of green algae in acidified streams; role of invertebrates in decomposition of leaves in acid waters; and recovery processes of fish and invertebrates after liming. (94 refs., 4 figs.)

  7. Diatoms as an indicator for tile drainage flow in a German lowland catchment

    Wu, Naicheng; Faber, Claas; Ulrich, Uta; Schmalz, Britta; Fohrer, Nicola


    The separation of flow components within a model simulation is of great importance for a successful implementation of management measures. Tracers are commonly used to identify and assess runoff-generating processes and to detect sources of stream flow components within a target catchment. Diatoms could be an ideal tracer due to their diverse preferences to different aquatic habitats (van Dam et al. 1994, Pfister et al. 2009). As a part of a DFG (Deutsche Forschungsgemeinschaft) project, we collected diatom samples of 9 sites (4 tile drainage, and 5 river sites) weekly or biweekly from March to July 2013 in a German lowland catchment (the Kielstau catchment). First results showed that diatom species Achnanthes lanceolata, Fragilaria biceps and Navicula ingapirca dominated in tile drainage flow with relative abundances of 22.2%, 21.5% and 10.9%, respectively. For river sites, the most abundant species was Navicula cryptocephala (20.5%), followed by Fragilaria biceps (12.9%), Cyclotella meneghiniana (9.5%) and Achnanthes lanceolata (9.3%). Compared with river sites, tile drainage flow had lower diatom density, biomass, species richness and percentage of Aquatic/Riparian diatoms (AqRi%). However, the proportion of Riparian diatoms (RiZo%) increased at tile drainage flow. Indicator value method (IndVal) revealed that the two water types were characterized by different indicator species. Fifteen taxa (e.g. Cocconeis placentula, Cyclotella meneghiniana, Navicula cryptocephala and Fragilaria biceps) were significant indicators for river sites. Achnanthes lanceolata, Achnanthes minutissima and Navicula ingapirca were significant indicators for tile drainage flow. These results highlight the suitability of diatoms as an indicator for tile drainage flow. Spatial and temporal variations of diatom community should be considered in future surveys. Keywords: Diatoms, Flow components, Indicator value method, Tracer References: Pfister, L., J. J. McDonnell, S. Wrede, D. Hl

  8. Fluoroscopy guided percutaneous catheter drainage of pneumothorax in good mid-term patency with tube drainage

    Park, Ga Young; Oh, Joo Hyung; Yoon, Yup; Sung, Dong Wook [Kyung Hee University Hospital, Seoul (Korea, Republic of)


    To evaluate efficacy and the safety of percutaneous catheter drainage in patients with pneumothorax that is difficult to treat with closed thoracotomy. We retrospectively reviewed effectiveness of percutaneous catheter drainage (PCD) in 10 patients with pneumothorax. The catheter was inserted under fluoroscopic guidance. Seven patients had spontaneous pneumothorax caused by tuberculosis (n =4), reptured bullae (n = 2), and histiocytosis-X (n = 1). Three patients had iatrogenic pneumothorax caused by trauma (n = 1) and surgery (n = 2). All procedures were performed by modified Seldinger's method by using 8F-20F catheter. All catheter were inserted successfully. In 9 of 10 patients, the procedure was curative without further therapy. Duration of catheter insertion ranged from 1 day to 26 days. In the remaining 1 patient in whom multiple pneumothorax occurred after operation, catheter insertion was performed twice. Percutaneous catheter drainage under fluoroscopic guidance is effective and safe procedure for treatment of pneumothorax in patients with failed closed thoracotomy.

  9. Terrestrial ice streams-a view from the lobe

    Jennings, C.E.


    The glacial landforms of Minnesota are interpreted as the products of the lobate extensions of ice streams that issued from various ice sheds within the Laurentide Ice Sheet. Low-relief till plains, trough-shaped lowlands, boulder pavements, and streamlined forms make up the subglacial landsystem in Minnesota that is interpreted as having been formed by streaming ice. Extremely uniform tills are created subglacially in a way that remains somewhat mysterious. At the ice margins, thrust moraines and hummocky stagnation topography are more common than single-crested, simple moraines if the ice lobes had repeated advances. Subglacial drainage features are obscure up-ice but are present down-ice in the form of tunnel valleys, eskers, Spooner hills, and associated ice-marginal fans. Ice streaming may occur when basal shear stress is lowered as a result of high subglacial water pressure. Subglacial conditions that allow the retention of water will allow an ice lobe to extend far beyond the ice sheet as long as the ice shed also supports the advance by supplying adequate ice. Even with adequate ice flux, however, the advance of an ice lobe may be terminated, at least temporarily, if the subglacial water is drained, through tunnel valleys or perhaps a permeable substrate. Thrust moraines, and ice stagnation topography will result from sudden drainage. Although climate change is ultimately responsible for the accumulation of ice in the Laurentide Ice Sheet, the asynchronous advances and retreats of the ice lobes in the mid-continent are strongly overprinted by the internal dynamics of individual ice streams as well as the interaction of ice sheds, which obscure the climate signal. ?? 2005 Elsevier B.V. All rights reserved.

  10. Climate Drivers of Alaska Summer Stream Temperature

    Bieniek, P.; Bhatt, U. S.; Plumb, E. W.; Thoman, R.; Trammell, E. J.


    The temperature of the water in lakes, rivers and streams has wide ranging impacts from local water quality and fish habitats to global climate change. Salmon fisheries in Alaska, a critical source of food in many subsistence communities, are sensitive to large-scale climate variability and river and stream temperatures have also been linked with salmon production in Alaska. Given current and projected climate change, understanding the mechanisms that link the large-scale climate and river and stream temperatures is essential to better understand the changes that may occur with aquatic life in Alaska's waterways on which subsistence users depend. An analysis of Alaska stream temperatures in the context of reanalysis, downscaled, station and other climate data is undertaken in this study to fill that need. Preliminary analysis identified eight stream observation sites with sufficiently long (>15 years) data available for climate-scale analysis in Alaska with one station, Terror Creek in Kodiak, having a 30-year record. Cross-correlation of summer (June-August) water temperatures between the stations are generally high even though they are spread over a large geographic region. Correlation analysis of the Terror Creek summer observations with seasonal sea surface temperatures (SSTs) in the North Pacific broadly resembles the SST anomaly fields typically associated with the Pacific Decadal Oscillation (PDO). A similar result was found for the remaining stations and in both cases PDO-like correlation patterns also occurred in the preceding spring. These preliminary results demonstrate that there is potential to diagnose the mechanisms that link the large-scale climate system and Alaska stream temperatures.

  11. The contribution of Distributed Temperature Sensing (DTS) in streams to assess spatial runoff processes in a moraine dominated agricultural catchment

    Boegh, Eva; Blemmer, Morten; Holmes, Esbern

    using a high spatial resolution (10-30 m) land use map which includes agricultural crops, forest, wetlands and inhabited areas, and spatial variations in soil types, geology and tile drainage were represented. The DTS system measured diurnal variations in water temperature each meter along a stream...... accumulation of water from individual grids within the catchment to the stream was calculated using a Lidar based (1.6 m resolution) digital elevation model. Many locations with observed (DTS-based) discrete lateral inflows were in good agreement with stream locations receiving extra large inflows from...

  12. Associations among land-use, habitat characteristics, and invertebrate community structure in nine streams on the island of Oahu, Hawaii

    Brasher, Anne M.D.; Wolff, Reuben H.; Luton, Corene D.


    The island of Oahu is one of 51 study units established as part of the U.S. Geological Surveys National Water-Quality Assessment (NAWQA) program to assess the status and trends of the Nations surface and ground-water resources, and to link status and trends with an understanding of the natural and human factors that affect water quality. As part of the NAWQA program, benthic invertebrate communities were surveyed at ten sites in nine streams representing the three main types of land use on Oahu: urban, agriculture, and forested. At each sampling site, habitat characteristics were determined at a range of spatial scales including drainage basin, segment, reach, transect, and point. Associations among land use, habitat characteristics, and benthic invertebrate community structure were examined. The rapid population growth and increasing urbanization on Oahu has resulted in substantial stream habitat alteration. Instream habitat characteristics at the urban and mixed (urban and agriculture) land-use sites were markedly different from those at the forested sites. Urban and mixed land-use sites, most of which were channelized, tended to have less riparian vegetation, higher water temperatures, smaller substrate, and higher levels of embeddedness and siltation than sites in forested watersheds. The majority of invertebrate taxa identified during this study were non-native. Invertebrate abundance was lower at urban and mixed land-use sites than at forested sites, while species richness (the number of different species) showed the opposite pattern. Multivariate analyses indicated that invertebrate species composition was similar at sites with similar land use. Aquatic insects of the orders Diptera and Trichoptera were the most common insects in all samples. The ratio of Diptera to Trichoptera abundance varied with urbanization. Forested sites were dominated by Trichoptera, and urban and mixed land-use sites were dominated by Diptera. Molluscs typically occurred in

  13. Lightweight query authentication on streams


    We consider a stream outsourcing setting, where a data owner delegates the management of a set of disjoint data streams to an untrusted server. The owner authenticates his streams via signatures. The server processes continuous queries on the union of the streams for clients trusted by the owner. Along with the results, the server sends proofs of result correctness derived from the owner's signatures, which are easily verifiable by the clients. We design novel constructions for a collection o...

  14. Pathways and transit time of meltwater in the englacial drainage system of Rabots Glacier, Kebnekaise, Sweden

    Coch, Caroline; Clason, Caroline; Rosqvist, Gunhild; Jarsjö, Jerker; Brugger, Keith


    Following the crash of a Norwegian Hercules plane in the Kebnekaise mountain range in March 2012, a field campaign was initiated in order to assess the fate of the hydrocarbon pollution in the glacial system. Monitoring of pollution was conducted in the snow pack of Rabots glacier, as well as in the proglacial stream, and the preferential pathways for transport of pollutants were assessed. Since it is likely that soluble components of the aircraft fuel are transported within the glacial meltwater, our study focuses on constraining the likely transit time and dispersion of these components. The hydrologic configuration of Rabots glacier was thus studied during the 2013 ablation season by means of dye tracing experiments and discharge monitoring in the proglacial stream. The analyses of the dye return curves and stream monitoring suggest different hydrological configurations on the north and south side of the glacier, perhaps influenced by shading and the ice thermal structure. The system on the north side seems to be distributed, with extensive interaction of meltwater with the bed, as typified in the turbid proglacial outlet. The distinct peaks of the return curves on the south side indicate efficient transport, perhaps largely through englacial channels, given the relatively clear nature of the proglacial outlet. The evaluation of transit speed along a longitudinal profile contributed to the understanding of drainage efficiency with distance upglacier. The higher up the injection location on the glacier, the more distributed and less efficient the system. The seasonal evolution of efficiency was also assessed, showing an increase inefficiency with time. Furthermore, we hypothesize a disconnect in the glacial hydrological systems on the north and south side of the glacier. Pollution that is transported with the meltwater down from the crash site on the southern side most likely does not reach the drainage system on the northern side. Besides revealing potential

  15. Subglacial water flow inferred from stream measurements at South Cascade Glacier, Washington, USA

    Fountain, A.G.


    Comparisons of water discharge and cation load in each of the two main streams indicate that subglacial hydraulic processes differ between drainage basins. One stream drains from a conduit that is isolated in its lower reach from the surrounding subglacial region and receives water routed englacially from the surface. The upper reach of the conduit also receives water rounted englacially from the surface as well as from a distributed subglacial flow system. The other main stream drains from a conduit coupled to a debris layer beneath the glacier. Observations of the layer in natural ice tunnels indicate that the water may flow within a thin layer of debris. A one-dimensional model of flow through the debris layer can explain both the base-flow and diurnal variations of the second main stream. -from Author

  16. Antimicrobial susceptibility pattern and epidemiology of blood stream infections in China, 2012%2012年度全国血标本来源细菌分布及耐药状况

    田磊; 朱旭慧; 孙自镛


    ,应根据药敏结果合理选用抗菌药物。%Objective To investigate the distribution and changing pa-ttern of susceptibility in bloodstream infection.Methods The blood cul-ture isolates from 557 tertiary hospitals and 232 second class hospitals were routinely isolated and identified.Antimicrobial susceptibility of these isolates were tested routinely.Results A total of 76483 strains were isolated from blood specimens in the tertiary hospitals during 2012.Gram-positive cocci and gram-negative bacilli accounted for 44.35%and 55.65%, respectively.A total of 6261 strains were isolated from blood specimens in the second-class hospitals during 2012.Gram-po-sitive cocci and gram -negative bacilli accounted for 48.89% and 51.11%, respectively.The most frequent gram-negative bacteria from the tertiary hospitals and the second -class hospitals were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii and Enterobacter cloacae, the most fre-quent gram-positive bacteria were Coagulase-negative Staphylococus, Staphylococus aureus, Enterococcus faecium and Enterococcus faecalis.700 strains of Streptococcus pneumoniae ( 0.8%) , 28 strains of Hemophilus influenza (80.0%).The sensitivity rates of Enterococcus faecalis to Pencillin and Ampicillin were high (>80.0%).Escherichia coli was sensitive to not only Ampicillin/Sulbactam and Piperacillin/tazobactam (>90.0%) , but also Amikacin and Cefoxitin ( about 80.0%).Pseudomonas aeruginosa was sensitive to all of the common antibiotics almost.But it was just the opposite to Acinetobacter baumannii.Polymyxin B and Cefoperazone/Sulbactam were sensitive to Acinetobacter baumannii in the tertiary hospitals and the second-class hospitals, respec-tively(97.6%and 76.7%).Conclusion The datas of 2012 indicated that gram-negative bacilli, especially Esche-richia coli, played an important role in blood stream infections.A large number of Coagulase-negative Staphylococus, Staphylococus aureus were isolated

  17. A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

    Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel


    Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (EMREE=0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Data Stream Classification Based on the Gamma Classifier

    Abril Valeria Uriarte-Arcia


    Full Text Available The ever increasing data generation confronts us with the problem of handling online massive amounts of information. One of the biggest challenges is how to extract valuable information from these massive continuous data streams during single scanning. In a data stream context, data arrive continuously at high speed; therefore the algorithms developed to address this context must be efficient regarding memory and time management and capable of detecting changes over time in the underlying distribution that generated the data. This work describes a novel method for the task of pattern classification over a continuous data stream based on an associative model. The proposed method is based on the Gamma classifier, which is inspired by the Alpha-Beta associative memories, which are both supervised pattern recognition models. The proposed method is capable of handling the space and time constrain inherent to data stream scenarios. The Data Streaming Gamma classifier (DS-Gamma classifier implements a sliding window approach to provide concept drift detection and a forgetting mechanism. In order to test the classifier, several experiments were performed using different data stream scenarios with real and synthetic data streams. The experimental results show that the method exhibits competitive performance when compared to other state-of-the-art algorithms.

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

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


    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.

  20. Biological and physical conditions of macroinvertebrates in reference lowland streams

    de Brouwer, Jan; Eekhout, Joris; Verdonschot, Piet


    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. Currently, stream restoration measures are being implemented in these degraded lowland streams</