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Sample records for river meander migration

  1. Meandering rivers: Interpreting dynamics from planform geometry and the secret lives of migrating meanders

    NASA Astrophysics Data System (ADS)

    Schwenk, Jonathan

    Meandering rivers are dynamic agents of geomorphic change that rework landscapes through migration while maintaining beautiful looping planforms. This work investigates the relationships between the alluring planform geometries of meandering rivers, the dynamics of individual meander bend migration, and the dynamic processes driving meander evolution. A simple yet physically-based model of long-time meander migration is employed to understand the dynamic trajectories of individual meander bends and establish relationships between historic dynamics and cutoff bend geometry. At the reach scale, concepts from nonlinear dynamic theory are applied to river centerlines to determine if the dynamic nonlinearities driving meander evolution are preserved in the reachwide planform structure. Understanding how rivers move across their floodplains requires snapshots of planforms over long time periods from aerial photography or historic maps and surveys which are often taken at irregular and long intervals. Migration occurring between snapshots has thus largely remained a mystery. More recently, worldwide satellite imagery collected at least every 18 days by the NASA Landsat family of satellites offers the potential to reveal the secret lives of migrating, meandering rivers. This research mines the vault of Landsat imagery to resolve over 30 years of planform migration along more than 1,300 km of one of the Earth's most active meandering rivers: the Ucayali River in Peru. Analysis of the resulting annual binary channel masks suggests that migration rates are controlled by processes acting across bend-to-reach scales. An exciting new geomorphic discovery emerges from the analysis revealing the role of cutoffs as drivers of nonlocal morphodynamic change.

  2. RVR MeanderMigration of meandering rivers in homogeneous and heterogeneous floodplains using physically-based bank erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The RVR Meander platform for computing long-term meandering-channel migration is presented, together with a method for planform migration based on the modeling of the streambank erosion processes of hydraulic erosion and mass failure. An application to a real-world river, with assumption of homogene...

  3. River meanders

    USGS Publications Warehouse

    Leopold, Luna Bergere; Langbein, Walter Basil

    1966-01-01

    The striking geometric regularity of a winding river is no accident. Meanders appear to be the form in which a river does the least work in turning; hence they are the most probable form a river can take

  4. Net local removal of floodplain sediment by river meander migration

    NASA Astrophysics Data System (ADS)

    Lauer, J. Wesley; Parker, Gary

    2008-04-01

    Erosion from the banks of meandering rivers causes a local influx of sediment to the river channel. Most of the eroded volume is usually replaced in nearby point bars. However, the typical geometry of river bends precludes the local replacement of all eroded material because (i) point bars tend to be built to a lower elevation than cutbanks and (ii) point bars tend to be shorter than the eroding portion of cutbanks because of channel curvature. In a floodplain that is in equilibrium (i.e., neither increasing nor decreasing in volume), sediment eroded from cut banks must be replaced elsewhere on the floodplain. The local imbalance caused by differences in bank height should be balanced primarily by overbank deposition, while the local imbalance caused by curvature should be balanced primarily by deposition in abandoned stream courses or oxbow lakes. Estimates of these local imbalances based on remotely sensed measurements of bank geometry and channel migration have been made on four systems in the United States: a 91-km reach of the Pearl River in Louisiana and Mississippi, a 62-km reach of the Bogue Chitto River in Louisiana, a 35-km reach of the Neuse River in North Carolina, and a 2.7-km reach of the Vermillion River in Minnesota. For these systems, the total local imbalance, integrated over many bends, ranged from 0.36 to 2.27 m 3/yr/m of valley length (0.15 to 1.32 m 3/yr/m of channel length), or 7 to 45% of gross cutbank erosion, with a typical value of about 17%. When compared with gauged suspended sediment data, the measurements provide estimates of the relative importance of floodplains for storing material transported by a river system. The data suggest that even if the studied systems are near long-term mass balance equilibrium (as opposed to undergoing net deposition or erosion), almost all of the sand and in some cases much of the silt and clay in transit through these systems is likely to have spent some time stored in an upstream floodplain.

  5. Migration and cutoff of meanders in the hyperarid environment of the middle Tarim River, northwestern China

    NASA Astrophysics Data System (ADS)

    Li, Zhiwei; Yu, Guo-An; Brierley, Gary John; Wang, Zhaoyin; Jia, Yanhong

    2017-01-01

    A meandering channel has developed in the middle Tarim River, the longest inland river flowing through a hyperarid environment in northwestern China. Although the drainage basin of the Tarim River extends over 1 million km2, flow in downstream reaches is largely restricted to summer months, and irrigation pressures have made the flood season increasingly short. The planform morphology, lateral migration rate, and cutoffs of 105 meanders were analysed using multiperiod remote sensing images and field survey analyses of channel bed and bank properties and of riparian vegetation cover. Results show that planform attributes of the meandering Tarim River are similar to those found in other environments. The ratio of the channel centreline length to the neck channel width of meanders ranges between 1.2 and 8.1, the bend curvature (ratio of bend radius to channel width) ranges between 0.30 and 2.8, and the average deflection angle of the bend apexes is 79.9°. Meander migration rates range from 1.4 to 96.7 m y- 1. From 2000 to 2013, 45 cutoffs occurred along the 400-km-long reach. As the riparian vegetation cover is sparse because of limited precipitation and because banks are comprised of dense roots, fine sand and silt materials, but lack clay, bank strength is limited and presents limited constraints upon bend movement.

  6. CLASSIFICATION AND BEHAVIOR OF MEANDER MIGRATION.

    USGS Publications Warehouse

    Martin, Edward H.; Shen, Hsieh W.; Glover, J. Ed

    1986-01-01

    Meander migrations on the Mississippi River between Cairo, Illinois and Baton Rouge, Louisiana for the time period between the years 1765 and 1930 were classified into six categories based on the nature of channel movements. During the time period between 1765 and 1900, man's disturbance on this river reach was relatively minor. This study was mainly based on measurements taken in the years 1765, 1825, 1887 and 1930. The six categories of meander migration were: downstream limb migration, downstream limb rotation, mainly upstream limb migration, upstream limb rotation, pure translation and pure expansion. It was determined that over 60% of future meander migrations could be predicted from the characteristics of each individual initial channel pattern.

  7. Minimizing the Error Associated With Measurements of Migration-Related Sediment Exchange on Meandering Rivers

    NASA Astrophysics Data System (ADS)

    Lauer, J. W.; Parker, G.

    2005-05-01

    The floodplains of meandering rivers represent reservoirs that both store and release sediment. Bed material is generally released from cut banks and replaced in nearby point bars wherever migration occurs. Measuring the associated bed material flux is important for tracing the movement of contaminants that may be mixed with the bed material. Approximations of this flux can be made using a representative channel depth and sequences of aerial photography to estimate average absolute migration rates (or reworked areas) between photographs. Error in the aerial photographs leads to a positive bias in computed release rates. A method for removing this bias is introduced that uses the apparent offset of fixed linear features such as roads (along smaller rivers) or abandoned channel courses (along larger rivers). Measuring the rate of release of fine sediment is important both for predicting the long term morphodynamic evolution of the channel/floodplain system and for tracing the movement of contaminants that may be adsorbed to the fine sediment. While fine sediment can be mixed throughout the depth of the floodplain, it is most concentrated in the upper portion of older parts of the floodplain where it has had time to accumulate through overbank deposition. Its release rate can be estimated using migration rates computed from aerial photography in combination with local measurements of bank topography, both of which are highly variable even within a given reach. Where detailed bank topography is available for an entire reach, estimating the release of fine sediment is relatively straightforward. However, detailed topography is often unavailable along the banks of large lowland rivers, forcing estimates of the fine material flux to be made using a relatively small number of physically surveyed cross-sections. It is not immediately clear how many cross sections are required for a good estimate. This study performs Monte Carlo simulations on a detailed topographic dataset

  8. Designing and Assessing Restored Meandering River Planform Using RVR Meander

    NASA Astrophysics Data System (ADS)

    Langendoen, E. J.; Abad, J. D.; Motta, D.; Frias, C. E.; Wong, M.; Barnes, B. J.; Anderson, C. D.; Garcia, M. H.; MacDonald, T. E.

    2013-12-01

    The ongoing modification and resulting reduction in water quality of U.S. rivers have led to a significant increase in river restoration projects over the last two decades. The increased interest in restoring degraded streams, however, has not necessarily led to improved stream function. Palmer and Allan (2005) found that many restoration projects fail to achieve their objectives due to the lack of policies to support restoration standards, to promote proven methods and to provide basic data needed for planning and implementation. Proven models of in-stream and riparian processes could be used not only to guide the design of restoration projects but also to assess both pre- and post-project indicators of ecological integrity. One of the most difficult types of river restoration projects concern reconstructing a new channel, often with an alignment and channel form different from those of the degraded pre-project channel. Recreating a meandering planform to provide longitudinal and lateral variability of flow and bed morphology to improve in-stream aquatic habitat is often desired. Channel meander planform is controlled by a multitude of variables, for example channel width to depth ratio, radius of curvature to channel width ratio, bankfull discharge, roughness, bed-material physical characteristics, bed material transport, resistance to erosion of the floodplain soils, riparian vegetation, etc. Therefore, current practices that use simple, empirically based relationships or reference reaches have led to failure in several instances, for example a washing out of meander bends or a highly unstable planform, because they fail to address the site-specific conditions. Recently, progress has been made to enhance a physically- and process-based model, RVR Meander, for rapid analysis of meandering river morphodynamics with reduced empiricism. For example, lateral migration is based on measurable physical properties of the floodplain soils and riparian vegetation versus

  9. Valley evolution by meandering rivers

    NASA Astrophysics Data System (ADS)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  10. Floodplain heterogeneity and meander migration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of horizontal heterogeneity of floodplain soils on rates and patterns of meander migration is analyzed with a Ikeda et al. (1981)-type model for hydrodynamics and bed morphodynamics, coupled with a physically-based bank erosion model according to the approach developed by Motta et al. (20...

  11. Quantifying Process-Based Mitigation Strategies in Historical Context: Separating Multiple Cumulative Effects on River Meander Migration

    PubMed Central

    Fremier, Alexander K.; Girvetz, Evan H.; Greco, Steven E.; Larsen, Eric W.

    2014-01-01

    Environmental legislation in the US (i.e. NEPA) requires defining baseline conditions on current rather than historical ecosystem conditions. For ecosystems with long histories of multiple environmental impacts, this baseline method can subsequently lead to a significantly altered environment; this has been termed a ‘sliding baseline’. In river systems, cumulative effects caused by flow regulation, channel revetment and riparian vegetation removal significantly impact floodplain ecosystems by altering channel dynamics and precluding subsequent ecosystem processes, such as primary succession. To quantify these impacts on floodplain development processes, we used a model of river channel meander migration to illustrate the degree to which flow regulation and riprap impact migration rates, independently and synergistically, on the Sacramento River in California, USA. From pre-dam conditions, the cumulative effect of flow regulation alone on channel migration is a reduction by 38%, and 42–44% with four proposed water diversion project scenarios. In terms of depositional area, the proposed water project would reduce channel migration 51–71 ha in 130 years without current riprap in place, and 17–25 ha with riprap. Our results illustrate the utility of a modeling approach for quantifying cumulative impacts. Model-based quantification of environmental impacts allow scientists to separate cumulative and synergistic effects to analytically define mitigation measures. Additionally, by selecting an ecosystem process that is affected by multiple impacts, it is possible to consider process-based mitigation scenarios, such as the removal of riprap, to allow meander migration and create new floodplains and allow for riparian vegetation recruitment. PMID:24964145

  12. Sediment driven meander migration in the Amazon Basin

    NASA Astrophysics Data System (ADS)

    Ahmed, J.; Constantine, J. A.; Dunne, T.

    2015-12-01

    Meander migration is the principal process controlling how river channels lengthen through time; despite this universal observation, little analysis has been dedicated to evaluating the mechanisms by which meanders accomplish this lengthening. Using an almost yearly archive of Landsat imagery, we show that meandering rivers in the Andes-Foreland Basin of the Amazon Basin lengthen linearly with centreline migration rate, in the absence of cutoff events. We characterised the dominant meander movement mechanism by defining an index we term the symmetry index. The index measures the ratio between downstream and upstream meander erosion about the apex and bounded by inflection points. Indices greater than one represent more translational meander deformation, that is, downstream migration, whereas indices close to one indicate more extensional migration (i.e., increasing meander amplitude). We expanded our dataset to 25 reaches from varying physiographic provinces across the basin. Our results suggest that rivers located in sediment-rich regions migrate more rapidly, and possess higher symmetry indices indicative of more translational bend development. Conversely, rivers with low sediment yields show more extensional bend development. Since alluvial material is responsible for the construction of point bars, rivers conveying larger sediment fluxes have the ability to build bars more quickly. Point bar growth increases channel curvature and deflects high-velocity fluid towards the outer bank encouraging bank erosion. An analysis of point bar locations along the banks of two meandering streams shows that bars positioned downstream of the apex correlate with bends that undergo translational development, whilst material deposited in the centre and upstream of the apex show more extensional and lobing evolution. These results suggest that point bar growth and its relationship to the sediment budget of rivers play an important role in meander migration.

  13. River meanders and vorticity theorem

    USGS Publications Warehouse

    Leopold, Luna Bergere

    1953-01-01

    The serpentine windings of rivers, which in certain reaches attain a remarkable symmetry and are then called meanders, must represent one aspect of the tendency for establishment of quasi-equilibrium in natural streams. With the increase in knowledge of the interaction of forces operating in rivers, this tendency toward equilibrium has assumed a greater significance.

  14. Numerical Simulations of Floodplain Heterogeneity Effects on Meanders Migration

    NASA Astrophysics Data System (ADS)

    Bogoni, M.; Lanzoni, S.; Putti, M.

    2014-12-01

    Floodplains and sinuous rivers have a close relationship with each other, mutually influencing their evolutions in time and space. The heterogeneity in erosional resistance has a crucial role on meander planform evolution. It depends on external factors, like land use and cover, but also on the composition of the floodplain, which is due to the ancient geological composition and to the processes associated to long-term river migration. In particular, banks erosion and deposition cause a variation of the superficial composition of the soil, therefore the river patterns are influenced by the previous trends. Based on some recent works, the aim of this contribution is to collect numerical information on the relations between meander migration and the heterogeneity of floodplains caused by oxbow lakes. Numerical simulations have been performed to analyze the temporal and spatial behavior of meanders with a range of values of the erosional resistance of the plain. These values are set as a function of some factors: the characteristic grain size of sediment transported by the flow, the deposition age of the sediments, the eventual presence of vegetation on the banks. The statistical analysis of characteristic geometrical quantities of meanders are able to show the dependence of the simulation results on the meander history. In particular we try to answer to the following questions: how do the rivers affect themselves during their spatial and temporal evolution, modifying the distribution of the floodplain erodibility? Do the migration history plays a main role on the meanders migration modeling?

  15. Don't Fence Me In: Free Meanders in a Confined River Valley

    NASA Astrophysics Data System (ADS)

    Eke, E. C.; Wilcock, P. R.

    2015-12-01

    The interaction between meandering river channels and inerodible valley walls provides a useful test of our ability to understand meander dynamics. In some cases, river meanders confined between valley walls display distinctive angular bends in a dynamic equilibrium such that their size and shape persist as the meander migrates. In other cases, meander geometry is more varied and changes as the meander migrates. The ratio of channel to valley width has been identified as a useful parameter for defining confined meanders, but is not sufficient to distinguish cases in which sharp angular bends are able to migrate with little change in geometry. Here, we examine the effect of water and sediment supply on the geometry of confined rivers in order to identify conditions under which meander geometry reaches a persistent dynamic equilibrium. Because channel width and meander geometry are closely related, we use a numerical meander model that allows for independent migration of both banks, thereby allowing channel width to vary in space and time. We hypothesize that confined meanders with persistent angular bends have smaller transport rates of bed material and that their migration is driven by erosion of the cutbank (bank-pull migration). When bed material supply is sufficiently large that point bar deposition drives meander migration (bar-push migration), confined meander bends have a larger radius of curvature and a geometry that varies as the meander migrates. We test this hypothesis using historical patterns of confined meander migration for rivers with different rates of sediment supply and bed material transport. Interpretation of the meander migration pattern is provided by the free-width meander migration model.

  16. River meanders - Theory of minimum variance

    USGS Publications Warehouse

    Langbein, Walter Basil; Leopold, Luna Bergere

    1966-01-01

    Meanders are the result of erosion-deposition processes tending toward the most stable form in which the variability of certain essential properties is minimized. This minimization involves the adjustment of the planimetric geometry and the hydraulic factors of depth, velocity, and local slope.The planimetric geometry of a meander is that of a random walk whose most frequent form minimizes the sum of the squares of the changes in direction in each successive unit length. The direction angles are then sine functions of channel distance. This yields a meander shape typically present in meandering rivers and has the characteristic that the ratio of meander length to average radius of curvature in the bend is 4.7.Depth, velocity, and slope are shown by field observations to be adjusted so as to decrease the variance of shear and the friction factor in a meander curve over that in an otherwise comparable straight reach of the same riverSince theory and observation indicate meanders achieve the minimum variance postulated, it follows that for channels in which alternating pools and riffles occur, meandering is the most probable form of channel geometry and thus is more stable geometry than a straight or nonmeandering alinement.

  17. Morphodynamic length scale and long term river meandering dynamics

    NASA Astrophysics Data System (ADS)

    Lanzoni, S.; Frascati, A.

    2009-12-01

    The fully nonlinear simulation of the lateral migration of meandering channels, combined with an analytical description of the linearized flow field, gives a powerful and yet computationally accessible tool to investigate short and long term evolution of alluvial rivers. In the present contribution we focus on the long term behavior of meandering rivers. This class of dynamical systems is driven by the coexistence of various intrinsically nonlinear mechanisms which determine the possible occurrence of two different morphodynamic regimes: the sub-resonant and the super-resonant regime. Investigating the full range of morphodynamic conditions, we end up with a new morphodynamic length scale associated with spatially oscillating disturbances, accounting for both curvature-forced variations in velocity and depth and alternate bars. Once normalized with this length scale, the relevant morphologic features of the simulated long term patterns (i.e. the probability density function of the local channel curvature and the geometric characteristics of the oxbow lakes) tend to collapse on two distinct behaviors, depending on the dominant morphologic regime. The long term river meandering dynamics is then investigated. The occurrence of cutoff events is a key mechanism in the dynamics of these systems. They introduce a strong source of nonlinearity in the evolution of river meandering, which strongly contributes to the formation of the complex planform patterns usually observed in nature. To detect the possible signatures of a chaotic behavior or a self-organized criticality state triggered in river meandering dynamics by the repeated occurrence of cutoffs, some robust nonlinear methodologies have been applied to both the spatial series of local curvatures and the time series of long term channel sinuosity. The temporal distribution of cutoff inter-arrivals is also investigated. The results are consistent and show that, at least from a modelling point of view, no evidence of

  18. Biomorphodynamic modelling of inner bank advance in migrating meander bends

    NASA Astrophysics Data System (ADS)

    Zen, Simone; Zolezzi, Guido; Toffolon, Marco; Gurnell, Angela M.

    2016-07-01

    We propose a bio-morphodynamic model at bend cross-sectional scale for the lateral migration of river meander bends, where the two banks can migrate separately as a result of the mutual interaction between river flow, sediments and riparian vegetation, particularly at the interface between the permanently wet channel and the advancing floodplain. The model combines a non-linear analytical model for the morphodynamic evolution of the channel bed, a quasi-1D model to account for flow unsteadiness, and an ecological model describing riparian vegetation dynamics. Simplified closures are included to estimate the feedbacks among vegetation, hydrodynamics and sediment transport, which affect the morphology of the river-floodplain system. Model tests reveal the fundamental role of riparian plants in generating bio-morphological patterns at the advancing floodplain margin. Importantly, they provide insight into the biophysical controls of the 'bar push' mechanism and into its role in the lateral migration of meander bends and in the temporal variations of the active channel width.

  19. River meanders and channel size

    USGS Publications Warehouse

    Williams, G.P.

    1986-01-01

    This study uses an enlarged data set to (1) compare measured meander geometry to that predicted by the Langbein and Leopold (1966) theory, (2) examine the frequency distribution of the ratio radius of curvature/channel width, and (3) derive 40 empirical equations (31 of which are original) involving meander and channel size features. The data set, part of which comes from publications by other authors, consists of 194 sites from a large variety of physiographic environments in various countries. The Langbein-Leopold sine-generated-curve theory for predicting radius of curvature agrees very well with the field data (78 sites). The ratio radius of curvature/channel width has a modal value in the range of 2 to 3, in accordance with earlier work; about one third of the 79 values is less than 2.0. The 40 empirical relations, most of which include only two variables, involve channel cross-section dimensions (bankfull area, width, and mean depth) and meander features (wavelength, bend length, radius of curvature, and belt width). These relations have very high correlation coefficients, most being in the range of 0.95-0.99. Although channel width traditionally has served as a scale indicator, bankfull cross-sectional area and mean depth also can be used for this purpose. ?? 1986.

  20. Analysis of Meander Migration Rates in Tidal Landscapes

    NASA Astrophysics Data System (ADS)

    Finotello, Alvise; D'Alpaos, Andrea; Ghinassi, Massimiliano; Lanzoni, Stefano; Marani, Marco; Rinaldo, Andrea

    2015-04-01

    Meandering patterns are universal features of tidal landscapes, which exert a great influence on the dynamics of tidal channel networks and on the stratigraphy of intertidal platforms. Despite their importance in landscape evolution and their ubiquity, tidal meanders have received less attention when compared to their fluvial counterparts. Quite a few studies, in fact, have focused on the morphodynamic evolution of tidal meanders, together with their planimetric shape and morphometric characteristics. To improve current understanding of tidal meander migration, a key step to address tidal meander evolution, we have analyzed a sequence of aerial photographs (from 1938 to present day) for about 400 meander bends, over 40 salt-marsh channels in the Northern part of the Venice Lagoon (Italy). Tidal meanders display similarities with fluvial meanders, although important differences emerge. Meanders cutting through the San Felice marsh follow the relationship between cartesian length and channel width, typical of meanders developed within different landscapes. However, meander migration rates, which were determined on the basis of three different methods, proved to be smaller than those characterizing fluvial meanders. Our analysis suggests mean migration rates of about 0.10 m/year, which is consistent with migration rates determined by previous studies on tidal meanders. The relationship between erosion (migration) rate and bend radius (R), both made dimensionless with channel width (W), displays a bell-shaped envelope pattern, in analogy with fluvial meanders although with smaller migration rates. In the tidal case, in fact, the largest migration rate is about 0.10 channel widths per year, which is smaller than the largest migration rate (0.20 channel widths per year) characterizing fluvial meanders that we found in the literature. Interestingly, in the case of tidal meanders the peak of the bell-shaped curve corresponds to a R/W ratio between 4 and 5, whereas the same

  1. Migration Rate Of Tidal Meanders: Inferences From The Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Finotello, A.; D'Alpaos, A.; Ghinassi, M.; Lanzoni, S.; Marani, M.; Rinaldo, A.

    2015-12-01

    Meandering channels are ubiquitous features of tidal landscapes. However, despite their fundamental role on the eco-morphodynamic evolution of these landscapes, tidal meanders have received less attention when compared to their fluvial counterparts. Improving current understanding of tidal meander migration, a largely-examined topic in fluvial landscapes, is a key step to highlight analogies and differences between tidal and fluvial cases. The migration of about 400 meander bends, belonging to 40 salt-marsh channels in the Northern Venice Lagoon (Italy), from 1968 to nowadays, has been investigated by means of both a classical method in fluvial frameworks and new procedure. Similarities with fluvial meanders occur, although important difference also emerge. Meanders cutting through the San Felice marsh follow the relationship between cartesian length and channel width, typical of meanders developed within different settings. However, meander migration rates proved to be smaller than those characterizing fluvial meanders. Indeed, the analysis of meander migration suggests a mean migration rate of about 0.10 m/year, consistent with the few data available in the literature. As for the fluvial case, the maximum-potential migration rate (i.e. the envelope curve of the relationship between migration rate and bend radius, both divided by channel width) reaches a maximum for radius-over-width ratio included between 2 and 3, regardless of the considered method. Nevertheless, the new-proposed method allows us to provide a more objective and continuous characterization. By using this new procedure, the channel curvature has finally been Fourier-analyzed, confirming the importance of even harmonics along the curvature spectrum. A correlation between migration rates and dominant harmonics seems to drive the evolution of tidal meanders and might represent a key-feature to distinguish them from their fluvial counterparts.

  2. River meander modeling and confronting uncertainty.

    SciTech Connect

    Posner, Ari J.

    2011-05-01

    This study examines the meandering phenomenon as it occurs in media throughout terrestrial, glacial, atmospheric, and aquatic environments. Analysis of the minimum energy principle, along with theories of Coriolis forces (and random walks to explain the meandering phenomenon) found that these theories apply at different temporal and spatial scales. Coriolis forces might induce topological changes resulting in meandering planforms. The minimum energy principle might explain how these forces combine to limit the sinuosity to depth and width ratios that are common throughout various media. The study then compares the first order analytical solutions for flow field by Ikeda, et al. (1981) and Johannesson and Parker (1989b). Ikeda's et al. linear bank erosion model was implemented to predict the rate of bank erosion in which the bank erosion coefficient is treated as a stochastic variable that varies with physical properties of the bank (e.g., cohesiveness, stratigraphy, or vegetation density). The developed model was used to predict the evolution of meandering planforms. Then, the modeling results were analyzed and compared to the observed data. Since the migration of a meandering channel consists of downstream translation, lateral expansion, and downstream or upstream rotations several measures are formulated in order to determine which of the resulting planforms is closest to the experimental measured one. Results from the deterministic model highly depend on the calibrated erosion coefficient. Since field measurements are always limited, the stochastic model yielded more realistic predictions of meandering planform evolutions. Due to the random nature of bank erosion coefficient, the meandering planform evolution is a stochastic process that can only be accurately predicted by a stochastic model.

  3. Experimental evidence for the conditions necessary to sustain meandering in coarse-bedded rivers.

    PubMed

    Braudrick, Christian A; Dietrich, William E; Leverich, Glen T; Sklar, Leonard S

    2009-10-06

    Meandering rivers are common on Earth and other planetary surfaces, yet the conditions necessary to maintain meandering channels are unclear. As a consequence, self-maintaining meandering channels with cutoffs have not been reproduced in the laboratory. Such experimental channels are needed to explore mechanisms controlling migration rate, sinuosity, floodplain formation, and planform morphodynamics and to test theories for wavelength and bend propagation. Here we report an experiment in which meandering with near-constant width was maintained during repeated cutoff and regeneration of meander bends. We found that elevated bank strength (provided by alfalfa sprouts) relative to the cohesionless bed material and the blocking of troughs (chutes) in the lee of point bars via suspended sediment deposition were the necessary ingredients to successful meandering. Varying flood discharge was not necessary. Scaling analysis shows that the experimental meander migration was fast compared to most natural channels. This high migration rate caused nearly all of the bedload sediment to exchange laterally, such that bar growth was primarily dependent on bank sediment supplied from upstream lateral migration. The high migration rate may have contributed to the relatively low sinuosity of 1.19, and this suggests that to obtain much higher sinuosity experiments at this scale may have to be conducted for several years. Although patience is required to evolve them, these experimental channels offer the opportunity to explore several fundamental issues about river morphodynamics. Our results also suggest that sand supply may be an essential control in restoring self-maintaining, actively shifting gravel-bedded meanders.

  4. RVR meander - a toolbox for river meander planform design and evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Restoring the meandering planform or spatial variability of historically meandering streams that have been channelized or highly disturbed is one of the most difficult aspects in river restoration. River planform and cross-sectional geometry are the result of complex interactions between flow, boun...

  5. Experimental investigation of Mars meandering rivers: Chemical precipitation process

    NASA Astrophysics Data System (ADS)

    Kim, W.; Lim, Y.; Cleveland, J.; Reid, E.; Jew, C.

    2014-12-01

    On Earth, meandering streams occur where the banks are resistant to erosion, which enhances narrow and deep channels. Often this is because the stream banks are held firm by vegetation. The ancient, highly sinuous channels with cutoffs found on Mars are enigmatic because vegetation played no role in providing bank cohesion and enhancing fine sediment deposition. Possible causes of the meandering therefore include ice under permafrost conditions and chemical processes. We conducted carbonate flume experiments to investigate possible mechanisms creating meandering channels other than vegetation. The experiment includes a tank that dissolves limestone by adding CO2 gas and produces artificial spring water, peristaltic pumps to drive water through the system, a heater to control the temperature of the spring water, and a flume where carbonate sediment deposits. Spring water containing dissolved calcium and carbonate ions moves through a heater to increase temperature, and then into the flume. The flume surface is open to the air to allow CO2 degassing, decrease temperature, and increase pH, which promotes carbonate precipitation. A preliminary experiment was done and successfully created a meander pattern that evolved over a 3-day experiment. The experiment showed lateral migration of the bend and avulsion of the stream, similar to a natural meander. The lateral variation in flow speed increased the local residence time of water, thus increasing the degassing of CO2 on the two sides of the flow and promoting more precipitation. This enhanced precipitation on the sides provided a mechanism to build levees along the channel and created a stream confined in a narrow path. This mechanism also potentially applies to Earthly single thread and/or meandering rivers developed and recorded before vegetation appeared on Earth's surface.

  6. Meandering down to the Sea: The Wandering Ways of Rivers.

    ERIC Educational Resources Information Center

    Aslamazov, Lev

    1992-01-01

    Discusses the hydrodynamic reasons why a riverbed meanders through a plain. Describes how water movement at a bend in a river causes erosion and changes in the riverbed. Provides a mathematical model to explain the periodic shape of meanders of a river in a plain. (MDH)

  7. Meander cutoffs nonlocally accelerate upstream and downstream migration and channel widening

    NASA Astrophysics Data System (ADS)

    Schwenk, Jon; Foufoula-Georgiou, Efi

    2016-12-01

    The hydrologic and sediment dynamics within and near cutoffs have long been studied, establishing them as effective agents of rapid local geomorphic change. However, the morphodynamic impact of individual cutoffs at the reachwide scale remains unknown, mainly due to insufficient observations of channel adjustments over large areal extents and at high temporal frequency. Here we show via annually resolved, Landsat-derived channel masks of the dynamic meandering Ucayali River in Peru that cutoffs act as perturbations that nonlocally accelerate river migration and drive channel widening both upstream and downstream of the cutoff locations. By tracking planform changes of individual meander bends near cutoffs, we find that the downstream distance of cutoff influence scales linearly with the length of the removed reach. The discovery of nonlocal cutoff influence supports the hypothesis of "avalanche"-type behavior in meander cutoff dynamics and presents new challenges in modeling and prediction of rivers' self-adjusting responses to perturbations.

  8. River channel patterns: Braided, meandering, and straight

    USGS Publications Warehouse

    Leopold, Luna Bergere; Wolman, M. Gordon

    1957-01-01

    Channel pattern is used to describe the plan view of a reach of river as seen from an airplane, and includes meandering, braiding, or relatively straight channels.Natural channels characteristically exhibit alternating pools or deep reaches and riffles or shallow reaches, regardless of the type of pattern. The length of the pool or distance between riffles in a straight channel equals the straight line distance between successive points of inflection in the wave pattern of a meandering river of the same width. The points of inflection are also shallow points and correspond to riffles in the straight channel. This distance, which is half the wavelength of the meander, varies approximately as a linear function of channel width. In the data we analysed the meander wavelength, or twice the distance between successive riffles, is from 7 to 12 times the channel width. It is concluded that the mechanics which may lead to meandering operate in straight channels.River braiding is characterized by channel division around alluvial islands. The growth of an island begins as the deposition of a central bar which results from sorting and deposition of the coarser fractions of the load which locally cannot be transported. The bar grows downstream and in height by continued deposition on its surface, forcing the water into the flanking channels, which, to carry the flow, deepen and cut laterally into the original banks. Such deepening locally lowers the water surface and the central bar emerges as an island which becomes stabilized by vegetation. Braiding was observed in a small river in a laboratory. Measurements of the adjustments of velocity, depth, width, and slope associated with island development lead to the conclusion that braiding is one of the many patterns which can maintain quasi-equilibrium among discharge, load, and transporting ability. Braiding does not necessarily indicate an excess of total load.Channel cross section and pattern are ultimately controlled by the

  9. Tidal Meander Migration: a Case Study from the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    D'Alpaos, A.; Ghinassi, M.; Bellucci, L. G.; Marani, M.

    2014-12-01

    Meandering patterns are universal features of tidal landscapes which exert a great influence on the dynamics of tidal channel networks and on the stratigraphy of intertidal platforms. Despite their importance in landscape evolution and their ubiquity, tidal meanders have received less attention when compared to their fluvial counterparts. Quite a few studies, in fact, have focused on the morphodynamic evolution of tidal meanders, together with their planimetric shape and morphometric characteristics. To improve current understanding of tidal meander migration and its possible stratigraphic implications, we have analyzed a sequence of aerial photographs (from 1938 to present day) for a 20 m in diameter, abandoned tidal meander in the Venice Lagoon, and have carried out high-resolution sedimentological and chronostratigraphical analyses of channel deposits. Aerial photographs before and after the cutoff event have been used to infer a minimum velocity of migration. Well-cores have also been collected along a transect crossing through the neck zone in order to evaluate changes in grain size, sedimentation rates across the cutoff event, and gain further insight into the velocity of migration of meander bends. Spatial distribution of sedimentary facies (pointbar sand, oxbowlake and saltmarsh mud), grain size analyses, and 210 Pb and 137Cs chronometers highlighted that meander cutoff occurred progressively around 60 years ago with a velocity of migration of about 0.5m/year. The effectiveness of the methods and the high spatial and temporal resolution of the data call for further investigations and analyses of the type proposed herein, furthermore highlighting the potentiality of the study area as modern analogue for ancient tidal deposits.

  10. Experimental evidence for the conditions necessary to sustain meandering in coarse-bedded rivers

    PubMed Central

    Braudrick, Christian A.; Dietrich, William E.; Leverich, Glen T.; Sklar, Leonard S.

    2009-01-01

    Meandering rivers are common on Earth and other planetary surfaces, yet the conditions necessary to maintain meandering channels are unclear. As a consequence, self-maintaining meandering channels with cutoffs have not been reproduced in the laboratory. Such experimental channels are needed to explore mechanisms controlling migration rate, sinuosity, floodplain formation, and planform morphodynamics and to test theories for wavelength and bend propagation. Here we report an experiment in which meandering with near-constant width was maintained during repeated cutoff and regeneration of meander bends. We found that elevated bank strength (provided by alfalfa sprouts) relative to the cohesionless bed material and the blocking of troughs (chutes) in the lee of point bars via suspended sediment deposition were the necessary ingredients to successful meandering. Varying flood discharge was not necessary. Scaling analysis shows that the experimental meander migration was fast compared to most natural channels. This high migration rate caused nearly all of the bedload sediment to exchange laterally, such that bar growth was primarily dependent on bank sediment supplied from upstream lateral migration. The high migration rate may have contributed to the relatively low sinuosity of 1.19, and this suggests that to obtain much higher sinuosity experiments at this scale may have to be conducted for several years. Although patience is required to evolve them, these experimental channels offer the opportunity to explore several fundamental issues about river morphodynamics. Our results also suggest that sand supply may be an essential control in restoring self-maintaining, actively shifting gravel-bedded meanders. PMID:19805077

  11. Evolution of cutoffs across meander necks in Powder River, Montana, USA

    USGS Publications Warehouse

    Gay, G.R.; Gay, H.H.; Gay, W.H.; Martinson, H.A.; Meade, R.H.; Moody, J.A.

    1998-01-01

    Over a period of several decades, gullies have been observed in various stages of forming, growing and completing the cutoff of meander necks in Powder River. During one episode of overbank flow, water flowing over the down-stream bank of the neck forms a headctu. The headcut migrates up-valley, forming a gully in its wake, until it has traversed the entire neck, cutting off the meander. The river then follows the course of the gully, which is subsequently enlarged as the river develops its new channel. The complete process usually requires several episodes of high water: in only one of the five cases described herein was a meander cutoff initiated and completed during a single large flood.

  12. An integrated approach to investigate the reach-averaged bend scale dynamics of large meandering rivers

    NASA Astrophysics Data System (ADS)

    Monegaglia, Federico; Henshaw, Alex; Zolezzi, Guido; Tubino, Marco

    2016-04-01

    Planform development of evolving meander bends is a beautiful and complex dynamic phenomenon, controlled by the interplay among hydrodynamics, sediments and floodplain characteristics. In the past decades, morphodynamic models of river meandering have provided a thorough understanding of the unit physical processes interacting at the reach scale during meander planform evolution. On the other hand, recent years have seen advances in satellite geosciences able to provide data with increasing resolution and earth coverage, which are becoming an important tool for studying and managing river systems. Analysis of the planform development of meandering rivers through Landsat satellite imagery have been provided in very recent works. Methodologies for the objective and automatic extraction of key river development metrics from multi-temporal satellite images have been proposed though often limited to the extraction of channel centerlines, and not always able to yield quantitative data on channel width, migration rates and bed morphology. Overcoming such gap would make a major step forward to integrate morphodynamic theories, models and real-world data for an increased understanding of meandering river dynamics. In order to fulfill such gaps, a novel automatic procedure for extracting and analyzing the topography and planform dynamics of meandering rivers through time from satellite images is implemented. A robust algorithm able to compute channel centerline in complex contexts such as the presence of channel bifurcations and anabranching structures is used. As a case study, the procedure is applied to the Landsat database for a reach of the well-known case of Rio Beni, a large, suspended load dominated, tropical meandering river flowing through the Bolivian Amazon Basin. The reach-averaged evolution of single bends along Rio Beni over a 30 years period is analyzed, in terms of bend amplification rates computed according to the local centerline migration rate. A

  13. Extreme sediment pulses generated by bend cutoffs along a large meandering river

    NASA Astrophysics Data System (ADS)

    Zinger, Jessica A.; Rhoads, Bruce L.; Best, James L.

    2011-10-01

    In meandering rivers, bend cutoffs have long been recognized as an important mechanism of change in the path of the channel. Meander bend cutoffs can develop by the progressive migration of an elongated bend onto itself, which forms a neck cutoff, or by the erosion of a new channel across the neck of the bend, which is known as a chute cutoff. River cutoffs affect channel navigation, and form meander scars and oxbow lakes in river floodplains, which are important habitats for riparian ecosystems. The importance of cutoff processes in meander dynamics is well established, but the effects of cutoffs on overall sediment flux are poorly characterized. Here we use aerial imagery, global positioning system mapping and measurements of channel bathymetry to estimate the amount of sediment released by two chute cutoffs on the Wabash River in the Midwestern USA. We find that each event triggered the rapid delivery of sediment into the river, at rates that are one to five orders of magnitude larger than those produced by lateral migration of individual bends. We find that much of this material was deposited immediately downstream, at the confluence of the Wabash and Ohio rivers, which led to significant changes in channel morphology. This sedimentation ultimately impeded barge traffic and necessitated extensive dredging.

  14. Rivers meandering in bedrock: Lithologic, climatic, and process controls on form and evolution

    NASA Astrophysics Data System (ADS)

    Zunka, J. P.; Lancaster, S. T.

    2014-12-01

    Whereas meander wavelengths of alluvial rivers characteristically scale with bankfull discharge, bedrock meander wavelengths are typically 5-10 times greater than the scaling relationship for alluvial rivers would suggest, a fact that has led some to conclude that bedrock meanders are "underfit." Others, however, have reasoned that larger dominant discharges should be expected for bedrock meanders to erode bank toes and mobilize sediment in bank-shielding scree piles, which often accompany steep, even vertical, outside banks capable of supplying coarse debris via landslide, debris flow, and rockfall. We attempt to test this hypothesis by finding dominant discharges for the Buffalo National River, Arkansas, by several methods. First, assuming that, as with alluvial meanders, bedrock meander wavelengths are 7-15 times hydraulic width at dominant discharge, we use cross-sections extracted from LiDAR-derived DEMs to find discharges corresponding to objectively-determined meander wavelengths. Second, assuming that dominant discharge must mobilize scree mantling outer-bank toe slopes, we use measured grain size distributions and cross sections to determine this discharge. For each of these calculated discharges, we use flow-duration curves to find corresponding recurrence intervals. Third, assuming that mean residence times of scree are similar to dominant discharge recurrence intervals, we use measured scree volumes and flux rates inferred from lateral migration rates to find those residence times. Preliminary results for the site with the longest gauge record yield a mean recurrence interval of 26 yrs corresponding to a meander wavelength-to-width scaling ratio of 11 (9-139 yrs for scaling ratios of 7-15). Recurrence intervals found by the other methods await field and cosmogenic isotope concentration measurements.

  15. River meandering on Earth and Mars: A comparative study of Aeolis Dorsa meanders, Mars and possible terrestrial analogs of the Usuktuk River, AK, and the Quinn River, NV

    NASA Astrophysics Data System (ADS)

    Matsubara, Yo; Howard, Alan D.; Burr, Devon M.; Williams, Rebecca M. E.; Dietrich, William E.; Moore, Jeffery M.

    2015-07-01

    The paleo-meanders in the Aeolis Dorsa (AD) region show that meandering channels can develop in the absence of vegetation. Three possible mechanisms other than vegetation could contribute to the bank cohesion required to promote meandering: permafrost, abundant mud, and chemical cementation. Banks at the meandering Quinn River show little vegetation cover. Almost all sediment samples collected from the Quinn River deposits contain at least 41% mud (silt/clay), which is much higher than for most meandering streams. Ion chromatography (IC) analysis and scanning electron microscope (SEM) images showed presence of salts in river waters and sediments which may induce fine sediment to flocculate and be deposited. We find that bank cohesion promoting meandering can be provided by silt/clay, the deposition of which may be induced by dissolved salts. The sinuous Usuktuk River in the continuous permafrost region near Barrow, Alaska exhibited no exposed permafrost on stream banks. Instead vegetation seemed to be the dominant control of bank erosion. We have not found evidence for ice control of bank cohesion in this or other terrestrial rivers of similar size and in meandering pattern to the Martian AD meanders. We conclude that bank cohesion in the AD meanders was probably provided by deposition of fine suspended sediment that was flocculated by dissolved salts.

  16. Detailed river stage mapping and head gradient analysis during meander cutoff in a laboratory river

    NASA Astrophysics Data System (ADS)

    Han, Bangshuai; Endreny, Theodore A.

    2014-02-01

    Analytical models of river evolution predict meander narrowing and elongation which creates sinuosity-driven hyporheic exchange across the meander neck, by decreasing flow distance and increasing head loss. We used a laboratory river table and close range photogrammetry to map and analyze sinuosity as a driver of head gradients and hyporheic exchange during cutoff. The river valley had relatively high slopes (1.8%) and moderately cohesive sediment (10% talc, 90% sand) to facilitate cutoff, and ratios of horizontal to vertical scaling were distorted to achieve dynamic similitude (Re = 3200). Incipient to cutoff, the head gradient across the neck increased due to a narrowing neck, upstream aggradation, and downstream degradation. Longitudinal and transverse river surface slopes around the meander bend increased as the meander approached cutoff. The steep head gradient across the moderately cohesive meander neck generated seepage erosion and scour that formed a low-sinuosity avulsion. Sediment-rich flow in the avulsed channel aggraded the downstream bed and separated the active channel and oxbow lake. The limitation in geometric and dynamic similitude in the river table limits extrapolation to natural rivers, yet river evolution may involve aggradation and degradation induced channel head loss and turnover hyporheic exchange as well as seepage-induced meander neck erosion. Our submillimeter maps of meander morphology and water stage provide data to parameterize river evolution and hyporheic exchange models, and may inform analysis and mapping of field sites.

  17. Rapid replacement of riparian rainforest habitat and the impacts on the meandering dynamics of the Kinabatangan River, Borneo

    NASA Astrophysics Data System (ADS)

    Horton, Alexander J.; Constantine, José A.

    2014-05-01

    Meandering rivers are defined by their nature to migrate, remobilising floodplain sediment and constructing new surfaces for riparian vegetation to colonise. The presence of riparian vegetation has long been known to limit the ability of rivers to erode riverbanks, but it has remained unclear the principal means by which vegetation provides this function. As a result, most models that predict meandering behaviour do not fully incorporate vegetation, thereby limiting their utility where forest is rapidly replaced. The problem is particularly acute along the Kinabatangan River of Sabah in Malaysian Borneo, where oil palm plantations are replacing one of the oldest riparian rainforests on the planet. The area of Sabah has seen rapid and extensive land use change in the last 40 years, as virgin rainforest has been systematically cleared for logging, and to make way for oil palm plantations. In the 18 years from 1990 to 2008, Sabah lost half of its intact rainforest, which equates to more than 1.85 million hectares. Using Landsat imagery dating back to 1973, we report here the impacts of this rapid land-use change on rates of meander migration on a 280-km reach of the Kinabatangan River. The river planform has been remarkably stable throughout the time period of study, but individual meanders show a rapid response to large discharge events, migrating over an order of magnitude faster than nearby reaches. Rapidly migrating meanders generally occur along portions of floodplain that have been artificially cleared of riparian vegetation, potentially resulting in significant increases in sediment load and within-channel bar development. A field campaign is planned to investigate the mechanisms by which riparian vegetation effect meander migration in these tropical regions.

  18. Revisiting nonlinearity in meandering river planform dynamics using Gradual Wavelet Reconstruc­­tion

    NASA Astrophysics Data System (ADS)

    Schwenk, J.; Foufoula-Georgiou, E.; Lanzoni, S.

    2014-12-01

    Characterizing the intrinsic nonlinearity in meandering river dynamics is important because it dictates river evolution response to perturbations such as bank armoring or channel straightening. Meandering river dynamics have been described in terms of chaos or self-organized criticality—characterizations predicated on the presence of nonlinearity—yet recent studies have found only limited evidence for its existence. Standard nonlinearity tests are performed by generating a number of linearized surrogate series from a signal of interest. Inherent nonlinearities in the original signal are destroyed in the surrogates via phase randomization in the Fourier domain. Nonlinearity is inferred if a significant difference exists between the original and the surrogates in an appropriately determined phase space. These tests detect the presence or absence of nonlinearity but cannot identify which scales and locations are contributing most to the signal's nonlinearity. A new surrogate generation method called Gradual Wavelet Reconstruction (GWR) has two key advantages over the standard methodology. First, GWR quantifies the degree of nonlinearity rather than simply detecting its presence or absence, providing a basis for comparisons between river planforms and models of meander migration. Second, because the GWR methodology relies on localized transformations, it can determine the scales and locations primarily contributing to the observed complexity. As a result of those advantages too, GWR has been shown to detect the presence of nonlinearity in signals where standard tests have failed. We apply GWR methodology to time series of channel sinuosity predicted by two established models of long-time meander migration: a HIPS-type model and that of Zolezzi and Seminara (2001). Although the former model has been shown to capture first-order meander dynamics, it fails to fully couple sediment and flow dynamics; nor does it account for the resonance phenomenon. Using GWR, we show

  19. Flow Structure and Channel Change in Chute Cutoffs On Meandering Rivers

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J. L.; Johnson, K. K.

    2011-12-01

    Freely meandering rivers typically exhibit complex, continuously evolving patterns of planform geometry involving elongation of the channel path through lateral migration and shorting of this path through bend cutoffs. Despite the importance of cutoffs in shaping the planform geometry of meandering rivers, the fluvial processes operative immediately after initiation of a cutoff are poorly understood. Two recent chute cutoff events on a single bend on the Wabash River, IL-IN, have provided an unprecedented opportunity to document the morphologic evolution and flow structure of chute cutoffs in a large, unregulated, meandering river. Here, we present results of ADCP measurements of three-dimensional flow velocity and bed topography at these cutoffs and describe a conceptual model for the morphodynamics of chute cutoffs prior to oxbow lake formation. Our results indicate that the flow structure at upstream and downstream ends of cutoff channels, prior to plugging of the entrance and exit of the abandoned bend with sediment, is analogous to flow through diffluence - confluence units. The interaction of this flow structure with an erodible bed and banks can cause rapid widening of the upstream end of the cutoff channel and bar development i) in the main channel where velocities are reduced, and ii) in the separation zone of the cutoff channel. Over time, these patterns of deposition and erosion will lead formation of an oxbow lake and complete capture of the flow by the cutoff channel.

  20. Captures, Cutoffs, and Autogenic Drainage Basin Reorganization from Bedrock River Meandering in the Oregon Coast Range

    NASA Astrophysics Data System (ADS)

    Johnson, K. N.; Finnegan, N. J.

    2015-12-01

    Meandering bedrock channels in the Oregon Coast Range (OCR), USA, have lateral migration rates far in excess of vertical incision rates. Consequently, the sweeping of trunk streams through this landscape can locally exert a much stronger influence on tributary channel long profiles than far-field tectonic forcing of base-level. Here, we use LiDAR-data to explore the influence of lateral channel mobility on the evolution of tributaries to the Smith River, in the OCR. We focus on two processes that dramatically and instantaneously change tributary long profiles: 1) Capture of tributaries by growing meander bends, and 2) Meander bend neck cutoffs on the main-stem that leave tributaries disconnected from base-level lowering. We focus on these two types of events because they provide clear examples of autogenic drivers of landscape disequilibrium at the sub-watershed scale in a landscape that is commonly argued to reflect steady tectonic forcing of base-level. We show that tributary streams are significantly more likely to flow into the leading edge of meander bends, testifying to the repeated capture of tributaries by growing bends. Examples of eminent captures by migrating bends, and examples with large knick points along recently captured tributaries suggest that the autogenic capture of tributaries by growing bends is a fundamental cause of transience in tributary channels in this landscape. To demonstrate the influence of the process of meander bend neck cutoff on tributary long profile evolution, we compare the long profiles of 34 tributaries that were hung above the main-stem of the Smith River following neck cutoff events. These stagnated tributary channels typically exhibit large convexities that record ongoing lowering of the trunk stream. Measured heights of these hanging tributaries implies that the timescale of adjustment for tributaries following cutoff events is ~ 105-106 years. The timescale of adjustment of tributary channels following meander cutoff

  1. A long term meander evolution simulation: A model evaluation using the field data from Quinn River, Nevada

    NASA Astrophysics Data System (ADS)

    Matsubara, Y.; Howard, A. D.; Burr, D. M.; Moore, J. M.; Williams, R. M.

    2011-12-01

    Despite the ubiquity of meandering streams, there have been few field-based studies of the temporal evolution of meander planforms, including modeling of channel migration and spatial patterns of floodplain. The Quinn River, located in the east branch of the Black Rock Desert, Nevada is a sinuous channel that flows through lacustrine sediments on the floor of paleolake Lahontan where vegetation cover is sparse. It is still active and aerial photographs taken over the past 50 years show that significant modifications including meander cutoffs have occurred in the past 40 years. This provides good basis for testing the ability of flow and bank erosion models (e.g., Johannesson and Parker [1989]) to predict meander evolution pattern. Meander model developed by Howard [1992, 1996], which has its base on the Johannesson and Parker [1989] linearized model of flow through bends, was used to simulate forward evolution of the Quinn River starting from the 1972 centerline. The Quinn River lacks bars and has a nearly canal-like cross-section with a flat bed, thus it is an ideal channel to test predictions of bend evolution. The model was calibrated by using various data such as meander wavelength, channel cross-sectional shape, measurements of flow resistance based upon the field work, and timing of meander cutoffs to find the model results that best match the 2010 centerline. We also formulated and calibrated the flood plain sediment deposition model using high resolution topography data from LiDAR. Our results show that the model well predicts the meander evolution pattern over historical time period. Also the short term simulations show a good correlation between the predicted inner and outer bend flow velocity ratio and the ratio of inner and outer channel bank slope ratio.

  2. Channel changes and floodplain management in the meandering middle Ebro River, Spain

    NASA Astrophysics Data System (ADS)

    Ollero, Alfredo

    2010-05-01

    The 346 km of the middle Ebro River between Logroño and La Zaida is a free meandering channel in a wide floodplain. This reach contains a discontinuous riparian corridor, including valuable riparian forests and oxbow lakes. The Ebro has witnessed substantial changes in channel morphology, gravel bars, riparian vegetation and floodplain uses over the last 80 years. The growth in sinuosity, migrations and meander cut-offs have been frequent before 1981. Afterwards, bank protections and dykes have stabilized the channel. There has been a progressive and significant decrease of both the area covered by water and the gravel bars without plant colonization. As a result the width of the riparian corridor has been dramatically reduced for human use. The deceleration and near elimination of the free meander dynamics of the Ebro channel represent an important loss of natural heritage. Dams, land-use changes throughout the basin, and construction of flood defences that restrict the main channel have changed the river system behaviour, which urgently needs a management plan combining both improvement and risk reduction. The solution proposed is the creation of a "Fluvial Territory".

  3. Influence of riparian vegetation on near-bank flow structure and erosion rates on a large meandering river

    NASA Astrophysics Data System (ADS)

    Konsoer, K. M.; Rhoads, B. L.; Langendoen, E. J.; Johnson, K.; Ursic, M.

    2012-12-01

    Rates of meander migration are dependent upon dynamic interactions between planform geometry, three-dimensional flow structure, sediment transport, and the erodibility and geotechnical properties of the channel banks and floodplains. Riparian vegetation can greatly reduce the rate of migration through root-reinforcement and increased flow resistance near the bank. In particular, forested riverbanks can also provide large woody debris (LWD) to the channel, and if located near the outer bank, can act to amour the bank by disrupting three-dimensional flow patterns and redirecting flow away from the bank-toe, the locus of erosion in meandering rivers. In this paper, three-dimensional flow patterns and migration rates are compared for two meander bends, one forested and one non-forested, on the Wabash River, near Grayville, Illinois. Flow data were obtained using acoustic Doppler current profilers (ADCP) for two large flow events in May and June 2011. LWD was mapped using a terrestrial LiDAR survey, and residence times for the LWD were estimated by comparing the survey data to time-series aerial photography. Rates of migration and planform evolution were determined through time-series analysis of aerial photography from 1938-2011. Results from this study show that near-bank LWD can have a significant influence on flow patterns through a meander bend and can disrupt helical flow near the outer bank, thereby reducing the effect of the high velocity core on the toe of the bank. Additionally, these effects influence migration rates and the planform evolution of meandering rivers.

  4. Morphodynamic regime and long-term evolution of meandering rivers

    NASA Astrophysics Data System (ADS)

    Frascati, Alessandro; Lanzoni, Stefano

    2009-06-01

    In the present contribution we focus our attention on the long-term behavior of meandering rivers, a very common pattern in nature. This class of dynamical systems is driven by the coexistence of various intrinsically nonlinear mechanisms which determine the possible occurrence of two different morphodynamic regimes: the subresonant and the superresonant regimes. Investigating the full range of morphodynamic conditions, we objectively compare the morphologic characteristics exhibited by synthetically generated and observed planimetric patterns. The analysis is carried out examining, through principal component analysis, a suitable set of morphological variables. We show that even in the presence of the strong filtering action exerted by cutoff processes, a closer, although not yet complete, similarity with natural meandering planforms can be achieved only by adopting a flow field model which accounts for the full range of morphodynamic regimes. We also introduce a new morphodynamic length scale, ?m, associated with spatially oscillating disturbances. Once normalized with this length scale, the relevant morphologic features of the simulated long-term patterns (e.g., the probability density function of local curvature and the geometric characteristics of oxbow lakes) tend to collapse on two distinct behaviors, depending on the dominant morphologic regime.

  5. Geomorphic and vegetation changes in a meandering dryland river regulated by a large dam, Sauce Grande River, Argentina

    NASA Astrophysics Data System (ADS)

    Casado, Ana; Peiry, Jean-Luc; Campo, Alicia M.

    2016-09-01

    This paper investigates post-dam geomorphic and vegetation changes in the Sauce Grande River, a meandering dryland river impounded by a large water-conservation dam. As the dam impounds a river section with scarce influence of tributaries, sources for fresh water and sediment downstream are limited. Changes were inspected based on (i) analysis of historical photographs/imagery spanning pre- (1961) and post-dam (1981, 2004) channel conditions for two river segments located above and below the dam, and (ii) field survey of present channel conditions for a set of eight reference reaches along the river segments. Whilst the unregulated river exhibited active lateral migration with consequent adjustments of the channel shape and size, the river section below the dam was characterized by (i) marked planform stability (93 to 97%), and by (ii) vegetation encroachment leading to alternating yet localized contraction of the channel width (up to 30%). The present river displays a moribund, stable channel where (i) redistribution of sediment along the river course no longer occurs and (ii) channel forms constitute a remnant of a fluvial environment created before closing the dam, under conditions of higher energy. In addition to providing new information on the complex geomorphic response of dryland rivers to impoundment, this paper represents the very first geomorphic assessment of the regulated Sauce Grande and therefore provides an important platform to underpin further research assessing the geomorphic state of this highly regulated dryland river.

  6. Measuring and modeling multidimensional dispersion in a meandering river

    NASA Astrophysics Data System (ADS)

    Logan, B. L.; Nelson, J. M.; Runkel, R. L.; McDonald, R. R.

    2009-04-01

    As part of a study to separate and characterize the active and passive components of sturgeon larval dispersal in a large river, we made detailed measurements of the dispersion of a large pulse of Rhodamine dye injected at a single upstream point. The study occurred on the Kootenai River, USA, a 200m-wide meandering river with an unusually low gradient, 2x10-5, and an average depth of 5 m at the moderate study flow of 271 m3/s. For the first 14 river kilometers downstream from the injection site, a detailed concentration data set describing the spatial and temporal evolution of the dye pulse was obtained using GPS receivers and high-accuracy fluorometers mounted on several boats. Beyond this initial reach, the dye was predominantly well-mixed in the cross-stream direction except near the leading and trailing edges of the pulse, and only longitudinal dispersion was measured. These measurements were made at a series of 11 fixed locations for an additional 45 river kilometers downstream, at which point peak dye concentrations were near the detection limit. Even for a relatively simple channel, the data indicate that local topography and bank irregularity exert a strong influence on the distribution of dye. While most of the dye pulse was apparently well mixed in the cross-stream and vertical directions, deep pools and lateral separation zones produced complex 3-dimensional structure in the concentration field, especially at the leading edge of the dye pulse. The dispersion data show that travel times in different reaches were more variable than predicted by a simple 1-dimensional model. Comparisons of the field data with results from multidimensional computational models indicate that uncommon channel features play a disproportionately important role in determining the storage and subsequent release of constituents that are passively advected and diffused.

  7. Changes in morphometric meander parameters identified on the Karoon River, Iran, using remote sensing data

    NASA Astrophysics Data System (ADS)

    Yousefi, Saleh; Pourghasemi, Hamid Reza; Hooke, Janet; Navratil, Oldrich; Kidová, Anna

    2016-10-01

    River meander dynamics and mobility are important indicators of environmental change related to climate changes and anthropogenic activities at local and river basin scales. The aim of the present study is to identify morphological changes of the Karoon River in Iran using high accuracy maps and Landsat satellite images by analyses during the time period 1989-2008. In this study, 20 meandering reaches were analyzed over a 128-km-long river reach located in the middle part of the Karoon River, Iran. Morphometric indicators such as: river width (W), meander neck length (L), axis length (A), radius of curvature (R), water flow length (S), and sinuosity of meander (C) were extracted for the identified meanders. The results of a paired t-test showed that river width (W) and meander neck length (L) have significantly changed during the study period (1989-2008), with an increase of + 3.5 m for W and a decrease of 274 m for L. Spearman correlation analysis has shown that meander parameter changes are highly correlated to each other. The parameters that do not have significant correlation together are C with W and L, W and L, and L with S and A. During the period of the study, the flow length and river sinuosity decreased for the whole river reach, by 4.77 km and 0.11, respectively. Analysis of land use/land cover categories (1989 and 2008) using the support vector machine (SVM) and kernel function method served as one of the tools for interpretation of the meander parameter changes. These changes can be attributed not only to LU/LC (riparian vegetation to agriculture area ratio) but also to dam construction in the upstream part of the river that leads to major hydrological regime and sediment transfer alteration. Sediment extraction may also be an important factor.

  8. HYDRODYNAMICS AND SEDIMENT TRANSPORT IN LOWER MISSISSIPPI RIVER MEANDER BENDS (LOUISIANA): IMPLICATIONS FOR LARGE SEDIMENT DIVERSIONS

    NASA Astrophysics Data System (ADS)

    Allison, M. A.; McCorquodale, A.; Meselhe, E. A.

    2009-12-01

    Field data collection and numerical modeling is being conducted in the lower Mississippi River in the region of a meander bend at Myrtle Grove, LA (river km 96 above Head of Passes) in support of a proposed large water and sediment diversion (1,130-2,830 cms) for coastal wetland restoration. Field studies in October 2008, April and May 2009, at discharges ranging from 11,000-21,000 cms, examined the role of bend dynamics on sediment transport through this reach relative to control sites further downriver and USGS monitoring stations upriver. Suspended loads and grain size character measured by ADCP (velocities and backscatter), isokinetic point sampler (P-63), and optical sensors (LISST, OBS, transmissometer) indicate that during the rising-to-high discharge phase, sand lifting off from the downstream edge of the lateral bar upriver of the bend augments that carried from further upriver, and is entrained in the upper 10-25m of the water column. This excess suspended sand is advected around the bend before concentrations are reduced to background levels over the lateral bar downstream of the bend. Bedload transport rates measured by repeat swath bathymetric mapping of migrating dunes are comparable upstream of the bend, downstream, and in the control sites. However, no bedforms are observed in the bend thalweg (up to 60 m deep) supporting the dominance of suspended sand transport in the bend. Both 1D (HEC-RAS and HEC6-T) and 3D (Flow3D) numerical hydrodynamic and sediment transport modeling is underway to simulate this process and the large-scale eddy present in the bend that generates upriver transport along the inside of the meander bend at all observed discharges. Our preliminary results suggest that the outside of meander bends might be an appropriate site for sediment diversions that draw near-surface water from this sediment-rich layer.

  9. Comparing the Planform Morphologies of a Freely Meandering Channel and the Bedrock- Controlled South River, VA.

    NASA Astrophysics Data System (ADS)

    Narinesingh, P.; Pizzuto, J.

    2008-12-01

    The planforms of the lithologically controlled South River, VA, and the freely meandering Teklanika River, AK were investigated using two statistical methods as well as fractal and spectral analyses. The lithologic controls along the South River include riverbanks consisting of pre-Holocene terraces and alluvial fans, and highly resistant bedrock that frequently crops out both in the bed and along the banks. A statistical analysis of bends composed of single arcs shows that the average radius of curvature is six times greater and the average bend length is 25 percent smaller for the South River relative to the meandering river, indicating that lithologically controlled bends are less curved and shorter than freely-formed meander bends. Fractal analysis reveals that the meandering river displays a smaller range in length scales than the South River, which exhibits a wider range in length scales that reflect a wider distribution of bend sizes. The method of Lancaster and Bras, (2002), which identifies bends of different complexity, indicates that the meandering river displays bends composed of single arcs, complex arcs and multiple complex arcs. Unlike the freely meandering Teklanika River, the lithologically controlled South River does not display bends composed of multiple complex arcs, though bends composed of single and complex arcs are common. Spectral analysis reveals that the meandering river's pattern is composed of a relatively narrow range of dominant wavelengths with the most prominent wavelength being the longest, while the lithologically controlled river displays dominant wavelengths over a relatively wide range and the most prominent wavelength is not the longest. This analysis demonstrates that lithological controls increase the range of bend lengths, increase radii of curvature, simplify bend shapes, and increase the distribution of wavelengths of sinuous rivers.

  10. The Influence of Variable Discharge on the Morphology of a Model Meandering River

    NASA Astrophysics Data System (ADS)

    Leverich, G. T.; Braudrick, C. A.; Sklar, L. S.; Dietrich, W.

    2006-12-01

    Large water storage dams have altered the morphology of many rivers by trapping sediment and decreasing the magnitude and duration of the seasonal peak flows that had been responsible for channel forming processes involving sediment transport. We hypothesized that a full range of flows, characteristic of pre-dam conditions, are critical for developing a dynamic, yet sustainable meandering floodplain river. We explored the role of variable flow as represented by a typical asymmetrically-shaped flood hydrograph in our physical model experiments of a scaled-down, gravel-bedded, meandering floodplain channel. Our model channel had erodible bed and banks and was allowed to evolve within a wide floodplain having a slope of one-half of a percent. Bank strength was provided using alfalfa sprouts and a thin layer of uniformly applied silica on the coarse floodplain sediments. We used a stepped hydrograph with a peak that resulted in overbank flooding, increased lateral migration rates, bar-connection with the floodplain, and stable channel width. The highest rates of bank erosion, bar growth, and lateral migration occurred during the overbank flows. We co-varied the bedload feed rate with the discharge while the sediment flux remained closely balanced over the course of each of the hydrograph runs, which was chiefly due to their shape. This occurred as the relatively longer durations of the final two hydrograph steps, where output rates exceeded input rates, compensated for the net increase of sediment storage within the channel during the rising limb steps. We additionally discovered that the ratio of deposition rates to erosion rates were not a function of discharge, but rather were dependent on the channel position relative to the apex of the migrating bend. Our research marks the first attempts at quantifying a channel's response to a systematic variation of flow in a three-dimensional physical model of a meandering floodplain river. This work applies directly to

  11. Steady-state unsteadiness: drainage network reorganization triggered by bedrock river meandering in the Oregon Coast Range

    NASA Astrophysics Data System (ADS)

    Johnson, K. N.; Finnegan, N. J.

    2013-12-01

    In most landscapes, vertical incision of bedrock stream networks transmits base-level signals into the landscape interior, and is thus the primary control on landscape evolution. Some bedrock channels, however, also have the capacity to move laterally within a landscape via active bedrock meandering. This is common in diverse lithologies including many sedimentary rocks (e.g. California and Oregon Coast Ranges, Colorado Plateau) and basalt (e.g. Columbia River Flood Basalt, Hawaiian Islands). If active meandering of the main stem channel occurs, rates of base-level lowering at the mouth of tributary watersheds will fluctuate over time, even if the base-level lowering rate at the mouth of the main stem channel is constant over time. This is because lateral migration of the main stem channel causes elongation or truncation of the lower reaches of tributaries, which in turn changes slopes and thus tributary incision rates. In addition, as meander bends along the main stem channel grow, they can capture tributaries from other main stem reaches, causing sudden drainage network reorganization and impulsive base-level lowering. Thus a landscape with steady tectonic and climatic forcing may nevertheless experience significant unsteadiness because of the process of meandering itself. Here we test our conceptual model that active meandering of a main stem channel exerts a fundamental control on the relative base-level lowering of tributary watersheds throughout the landscape. To this end, we analyze high resolution LiDAR elevation data from the Smith River, in the Oregon Coast Range, argued to be a classic example of a 'steady state' landscape. We find that tributary junctions are concentrated on the outside of active meander bends, consistent with the hypothesis that actively growing meander bends 'collect' tributaries as they propagate into the landscape. In addition, we find that longitudinal profiles of these tributaries are not consistent with a 'steady state' condition

  12. Morphodynamics of neck cutoffs on elongate meander loops, White River, Arkansas, USA

    NASA Astrophysics Data System (ADS)

    Konsoer, K. M.

    2015-12-01

    Meander cutoff and oxbow lake formation are essential components of alluvial architecture and riverine habitat of meandering river floodplains. Yet, despite their ubiquitous presence within active floodplains, the detailed processes involved in the initiation of cutoffs and oxbow lakes remain incompletely understood, primarily due to the intermittent nature of such events. Furthermore, conceptual models of meander cutoff and oxbow lake formation have been primarily developed for chute cutoffs and relatively simple planform configurations. Less attention has been given to neck cutoff dynamics occurring on highly sinuous meandering rivers with complex planform morphology. During the formation of a neck cutoff on a compound elongate loop, the upstream and downstream limbs can become oriented roughly subparallel with flow in opposite directions separated by a narrow meander neck. Immediately following cutoff of this thin neck, flow from the upstream limb is sharply redirected into the downstream limb over a short distance. These conditions of tight bend flow should become more pronounced as the ratio of radius of curvature to channel width become smaller, leading to complex patterns of three-dimensional velocities that have implications for the evolution of the cutoff channel and the transformation of the abandoned bend into an oxbow lake. This paper investigates the process dynamics of neck cutoff and oxbow lake formation using detailed field measurements of three-dimensional flow velocities, channel bed topography and geotechnical analysis of the banks and floodplains from three neck cutoffs along the White River, Arkansas (USA), each representing a different stage in the morphologic evolution from cutoff to oxbow lake. Results from this study suggests that the planform geometry of neck cutoff on an elongate meander loop can influence the spatial pattern of sediment deposition within the abandoned loop leading to increased hydrologic connectivity to the main channel

  13. Georectification of historical aerial photos to track meander change in Wood River, Klamath County, Oregon

    NASA Astrophysics Data System (ADS)

    Nash, C.; Hughes, M. L.

    2010-12-01

    The Wood River in Oregon’s Upper Klamath Basin is a meandering channel draining the southeastern slopes of Crater Lake National Park. Its valley floor is heavily grazed and highly altered by a series of irrigation channels that have substantially affected the river’s spring-fed flow regime and morphology. Despite efforts to restore the river’s hydrology, very little information is available about the river’s geomorphology. Using high-resolution LIDAR data from 2004 and georectified aerial photos from 1940-2009, we analyzed meander changes along the Wood River in the geomorphic context of its valley floor and meander belt. Aerial photos were scanned to produce digital images with sub-meter pixels, then georectified with a second-order polynomial transformation. Nine or fewer ground-control points were used for each photo to achieve an overall root-mean-square error value of 0.6 - 0.7 m. The scarcity of buildings and changes in the road and fence networks over the study period required the partial use of “natural pattern matching” during photo rectification. Semi-permanent patterns of fan erosion on the upper valley floor and hydrogeomorphic wetland patterns in lower valley provided the primary bases for natural pattern matching, further aided by the use of transparency during photo overlaying. Six prototypes of meander change were identified: extension, compression, translation, rotation, compound heading, and cutoff. Of these types, extension of meanders was the most frequently occurring. However, the effects of extension were counteracted by numerous meander cutoffs, which nominally affected sinuosity, but actually shortened the channel by about 1 km, or about 3%. Cutoffs were most frequent in the upper reaches of the river, where valley slope is higher, the meander belt is wider, and accommodation space was adequate to promote relatively high initial sinuosity. In these reaches, some cutoffs appear to have initiated downstream transfers of bedload

  14. The potential for dams to impact lowland meandering river floodplain geomorphology.

    PubMed

    Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

    2014-01-01

    The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.

  15. The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology

    PubMed Central

    Marren, Philip M.; Grove, James R.; Webb, J. Angus; Stewardson, Michael J.

    2014-01-01

    The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows. PMID:24587718

  16. Numerical simulations of inherited sinuosity and valley entrenchment in mixed alluvial- and bedrock-banked meandering rivers

    NASA Astrophysics Data System (ADS)

    Limaye, A.; Lamb, M. P.

    2013-12-01

    Highly sinuous rivers inset in bedrock canyons have long piqued the interest of geomorphologists because this sinuous morphology evokes comparisons to more actively migrating rivers with relatively weak sediment banks. An extensive literature debates the degree to which meandering rivers in bedrock valleys have inherited their sinuosity from previous alluvial states, or instead actively maintain sinuosity through bank migration at a rate sensitive to environmental characteristics (e.g., climate and lithology). This distinction is essential to evaluating whether bedrock channel sinuosity and valley morphology can be used to infer regional base-level and climate history, or instead reflect initial conditions. Previous work has considered sinuosity inheritance to occur by river vertical incision directly translating the form of a meandering channel from its alluvial state to a bedrock-bound state, yet the rate of vertical incision required to cause this state transition is uncertain. Here we explore the hypothesis that feedbacks between channel lateral migration and vertical incision, communicated through the composition of the channel banks, may influence channel planform geometry during an alluvial-to-bedrock transition. We use a numerical model to evaluate the transient morphologic and kinematic response of an alluvial river to different vertical incision histories and initial valley configurations. The model uses a vector-based framework for bank-material tracking to precisely model feedbacks between channel lateral migration and bank strength. Model results suggest that the tendency for a channel to remain highly laterally mobile depends on the vertical incision rate, but also on the width of the valley formed by lateral channel migration: bedrock valley floors are more easily bevelled by channel sweeping within narrow valleys than for wide valleys. For cases in which the channel cannot bevel across the initial valley width, lateral variations in bank strength

  17. Spatiotemporal variations in channel changes caused by cumulative factors in a meandering river: The lower Peixe River, Brazil

    NASA Astrophysics Data System (ADS)

    Morais, Eduardo S.; Rocha, Paulo C.; Hooke, Janet

    2016-11-01

    Channel changes in meandering rivers naturally exhibit complex behaviour, and understanding the river dynamics can be challenging in environments also subject to cumulative human impacts. Planform changes were analysed on four reaches of the lower course of the Peixe River, Brazil, at decadal scales over the period 1962-2008 from aerial photographs and satellite imagery, complemented by a historical map from 1907. Analysis of the spatial and temporal patterns of channel change mechanisms and morphometry of bends and of the sinuosity and morphodynamic variations of the reaches demonstrates major changes in planform characteristics. Sinuosity in all reaches decreased from 2.6 to 1.7, average wavelength of bends has increased from 200 to 500 m, and the planform has become much simpler. Changes have been progressive from downstream to upstream, with higher intensities of processes, particularly cutoffs first in downstream reaches then more recently in upstream reaches. It is suggested that channel changes represent a morphological adjustment to human interventions, such as reservoir construction and land use. However, evidence of the autogenic behaviour of meanders is highlighted in which the existence of compound meanders reveals control over the spatial variation in the reaches. The results suggest that geomorphic thresholds associated with the compound meander formation and the bend evolution should be considered, even in impacted meandering rivers, because they exert primary controls on the spatial-temporal adjustment of channels.

  18. On the analysis of the medium term planform dynamics of meandering rivers

    NASA Astrophysics Data System (ADS)

    Gutierrez, Ronald R.; Abad, Jorge D.

    2014-05-01

    The continuous wavelet transform is applied to the analysis of curvature signals from both synthetic meanders and 52 realizations from 16 natural meanders ranging from class B to class G (Brice classification), thus providing information on the spatial distribution of their arc-wavelength spectrum, and therefore, representing an objective characterization of meanders. Past research has studied the meander dynamics by using the centerline (short-term frame) and the valley centerline (long-term frame). The present study introduces a medium term frame, termed the mean center (MC), which is defined as the medium term coherent wave being present in the meander planimetry for a period that is strongly governed by the occurrence of cutoff events; although in the absence of them, it is present for ˜10 to ˜30 years. The MC is obtained by using a methodology that combines the capabilities of the principal component analysis and the discrete wavelet transforms. The application of wavelet cross correlation shows that peaks in the centerline curvature are strongly correlated with those of the MC suggesting that (1) a linear relationship between them may be associated to bank processes and, (2) in all other cases, a higher nonlinear relationship may be induced by autogenic hydrodynamic processes. In freely meandering rivers, compound bends, multiple loops, and cutoff events are associated to peaks in the MC local curvature. We define the planform amplitudes as the orthogonal distance of the centerline from mean center. Planform amplitudes (orthogonal distance of the centerline from mean center) are normally distributed and ranges from 2 to 20 river mean widths.

  19. Three-Dimensional Flow Fields and Bedform Migration in a Field-Scale Meandering Channel

    NASA Astrophysics Data System (ADS)

    Kozarek, J. L.; Palmsten, M. L.; Calantoni, J.; Khosronejad, A.; Sotiropoulos, F.

    2012-12-01

    The St. Anthony Falls Laboratory Outdoor StreamLab (OSL) at the University of Minnesota was constructed in 2008 as field-scale sand bed meandering stream channel within a vegetated floodplain. This state-of-the-art facility provides the unique opportunity to investigate physical, chemical, and biological stream and floodplain processes in a controlled outdoor environment with laboratory-quality measurement capabilities. The research presented here summarizes results from several experiments conducted in the OSL examining the effect of three-dimensional (3-D) flow fields on sediment transport and bedform development. Specifically, we examined bedform dimensions and flow fields in two scenarios 1) in the vicinity immobile rock structures, and 2) on the quasi-equilibrium bar that formed on the inner bank of a meander. A combination of methods were used for each study to determine the rate of scour hole formation, quasi-equilibrium bed elevation and variation in bed elevation, and bedform size and spacing. Bed topography data were collected at 1 cm resolution under live-bed conditions using a downward looking sonar probe attached to a mobile data acquisition (DAQ) cart. At each DAQ station, repeat scans were collected giving insight into the 3-dimensionality of bedforms in a meandering channel with and without rock structures. Supplementary data were collected at transects under two flow and sediment conditions (280 L/s and 6 kg/min and 199 L/s and 4 kg/min, for water and sediment, respectively) using an acoustic Doppler velocimeter (ADV) and a profiling ADV to measure 3-D flow fields and concurrent velocity and bed elevation data. These data were used in conjunction with data from optical remote sensing of bedform migration in the OSL to provide a validation dataset for a high-resolution 3-D hydro-morphodynamic model that is being used to simulate flow and sediment transport processes in meandering channels with embedded rock structures (Khosronejad et al. Adv. in

  20. The meandering-braided river threshold: A reappraisal

    NASA Astrophysics Data System (ADS)

    Carson, M. A.

    1984-08-01

    The concept of a threshold discharge-slope (Q-s) combination that separates braided from meandering streams is critically re-examined, partly by review of previous data, and partly by analysis of new data from South Island, New Zealand. It is argue d that discriminant functions that use mean annual discharge provide a poor physical basis for interpretations based on natural processes, while bankfull discharge is also deficient because it is not a fully independent variable. The common use of channel (rather than valley) slope adds a further misleading component because channel slope is partly dependent on channel pattern sinuosity. Most previous studies have inadequately treated the role of bed particle size in pattern discrimination, failing to recognize that active gravel streams must plot higher on a Q-s chart than sand-bed channels — irrespective of pattern — because of the greater power requirements for bed material movement. Within any one size class of bed material there is no evidence to indicate a clear discrimination between braiding and meandering, only a weak statistical association between pattern and slope-discharge values. While this association may be explicable in terms of the high shear stress and stream power (that accompany high Qs-values) promoting braiding, the real prerequisite for braiding appears to be high loads of bed-calibre material (producing wide shallow channels), a factor that is only partly controlled by stream power. Accordingly, the search for a pattern threshold based on discharge and slope seems to be a futile exercise. An interpretation of existing pattern discriminant functions from the perspective of the threshold shear stress for particle movement is made. It is concluded that, in effect, these functions merely state that gravel-bed streams are more likely to be braided than channels in finer sediment. Statistically this appears to be valid, and reasons for that difference are offered based on the balance between

  1. Asymmetrical Changes in Hydraulic Gradient Along Valley and River Transects During Meander Cutoff Evolution

    NASA Astrophysics Data System (ADS)

    Han, B.; Endreny, T.

    2009-05-01

    This work is motivated by the uncertainty about the presence and rate of steepening in river and valley hydraulic gradients bounding meander bends during meander cutoff, and how these gradients may affect river restoration designs. Our science question is whether the river and valley hydraulic gradients are equal and unchanging during meander cutoff. Laboratory investigations are underway prior to field experiments and model simulations. The laboratory physical model is a 2.1m x 0.9m EmRiver Process Simulator, running approximately 20 minutes per simulation, using particulate matter with a specific gravity of 1.6, a flow rate of 45ml/s, an initial river cross-section averaging 24cm2, and a range of radius of curvature from 15cm to 18cm. We calculated gradient using river water surface and valley watertable measurements, and their separation along a fixed orientation parallel to the valley slope, not along the thalweg. Measurements were taken with auto level, rod, and tape, and orthoimagery was captured to refine estimates of channel geometry. The ERDAS Leica Photogrammetry Suite processes digital images to generate digital elevation models (DEM) of the system. Initial results have confirmed a steepening of the river hydraulic gradient, from 4% to 5.5% for initial radius of curvature of 15cm, and from 7.7% to 10.9% for curvature of 18cm. The valley watertable gradient has a slight reduction or flattening of about 0.4%. Changes in channel geometry during cutoff include adjustments to cross-sectional area and increasing meander wavelength and sinuosity.

  2. Dynamic Modeling of Meandering Alluvial Channels

    NASA Astrophysics Data System (ADS)

    Lan, Yongqiang

    1990-01-01

    The migration of meandering alluvial channels is investigated theoretically, numerically, and experimentally. An equation for the rate of bank erosion is derived from a two-dimensional continuity equation for sediment transport linked with the depth-averaged dynamic flow equations. A simple one-dimensional theoretical analysis of meander migration leads to a relationship between the migration rate and the relative channel curvature and sediment properties. The simple model appropriately simulates the pattern and rate of meander expansion and migrations of the White River, Indiana and the East Nishnabotna River, Iowa. Application of the one-dimensional model to sine -generated alluvial channels indicates that meander migration reaches its maximum when the relative radius of curvature reaches about 4.8, or when the sinuosity of meander approaches 1.3. A two-dimensional numerical model, DYNAMIC, which predicts both lateral and longitudinal migration of alluvial channels is then developed, based on a system of quasi -steady depth-averaged flow dynamic equations, a sediment continuity equation, and a bank erosion equation. A linear analysis of the two-dimensional model leads to a convolutional relation between the rate of meander migration and flow and sediment properties. In the two-dimensional numerical analysis, a numerical algorithm called FLOWSOL is developed to solve the flow dynamic equations. The flow algorithm is then linked to the sediment continuity equation and bank erosion equation to simulate bed deformation and bank erosion. The developed two-dimensional model is applied to calculate the velocity profiles in Rozovskii's experiments and the bed deformation and shear stress in Hooke's experiments. Good agreement is obtained between the calculated and measured velocities, shear stresses and bed profiles in all experiments. Small scaled meandering rivers are developed successfully on a floodplain with or without cohesive materials (about 3%) in a wide

  3. Exposure of late Pleistocene Mississippi River meander-belt facies at Mt. Pleasant, Louisiana

    SciTech Connect

    Autin, W.J.; Davison, A.T.; Miller, B.J.; Day, W.J.; Schumacher, B.A.

    1988-09-01

    Exposure of a sedimentary sequence along a Mississippi River bluff at Mt. Pleasant, Louisiana, provides insight into the construction of the Prairie Terraces. This site serves as a type section for a late Pleistocene meander belt of the Mississippi River, and stratigraphic features have been traced beneath the Prairie Terraces in southeastern Louisiana. A 23.35-m measured section reveals upper units of Peoria loess and mixed loess. The described meander-belt facies are of a probable Wisconsin age and are here named the Mt. Pleasant Bluff alloformation. This age designation is based on position in the stratigraphic section, degree of preservation of sedimentary facies, character and degree of development of the upper paleosol, preservation of constructional topography beneath the loess, and correlation of this sequence to nearby sites with Wisconsin-age radiocarbon dates.

  4. Meandering stream reservoirs

    SciTech Connect

    Richardson, J.G.; Sangree, J.B.; Sneider, R.M.

    1987-12-01

    Braided stream deposits, described in a previous article in this series, and meandering stream deposits commonly are excellent reservoirs. Meandering high-sinuousity channels are found on flat alluvial plains with slopes less than 1 1/2/sup 0/ (0.026 rad). These rivers have wide ranges of discharges from low-water flow to flood stage. Two main processes are responsible for development of sand bodies. These are point-bar deposits left by channel migration, and oxbow-lake deposits left in loops of the river course abandoned when the stream cuts a new course during flooding. Extremely high floods spill over the banks and deposit sheets of very fine sand, silt, and clay onto the flood plain.

  5. Coevolution of floodplain and riparian forest dynamics on large, meandering rivers

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Riddle, J. D.; Battles, J. J.

    2012-12-01

    On large meandering rivers, riparian forests coevolve with the floodplains that support them. Floodplain characteristics such as local disturbance regime, deposition rates and sediment texture drive plant community dynamics, which in turn feed back to the abiotic processes. We investigated floodplain and riparian forest coevolution along the along the Sacramento River (California, USA), a large, mediterranean-climate river that has been extensively regulated for 70 years, but whose 160-km middle reach (Red Bluff to Colusa) retains some channel mobility and natural forest stands. Guided by maps of floodplain change over time and current vegetation cover, we conducted an extensive forest inventory and chronosequence analysis to quantify how abiotic conditions and forest structural characteristics such as tree density, basal area and biomass vary with floodplain age. We inventoried 285 fixed-area plots distributed across 19 large point bars within vegetation patches ranging in age from 4 to 107 years. Two successional trajectories were evident: (1) shifting species dominance over time within forested areas, from willow to cottonwood to walnut, boxelder and valley oak; and (2) patches of shrub willow (primarily Salix exigua) that maintained dominance throughout time. Sediment accretion was reduced in the persistent willow plots compared to the successional forest stands, suggesting an association between higher flood energy and arrested succession. Forested stands 40-60 years old were the most extensive across the chronosequence in terms of floodplain area, and supported the highest biomass, species diversity, and functional wildlife habitat. These stands were dominated by Fremont cottonwood (Populus fremontii) and reached their maxima in terms of tree size and biomass at age 50 years. The persistent willow stands reached their structural maxima earlier (32 years) and supported lower biomass. Basal area and abundance of large trees decreased in stands >90 years old

  6. Response of lateral channel dynamics of a lowland meandering river to engineering-derived adjustments - an example of the Morava River (Czech Republic)

    NASA Astrophysics Data System (ADS)

    Ondruch, Jakub; Mácka, Zdenek

    2015-11-01

    Freely meandering (quasi)natural reaches of lowland rivers represent a rare phenomenon in Central Europe. Increasing attention is currently being paid to the dynamics of quasi-natural (artificially influenced) meandering rivers as this attention represents the basic prerequisite for the development of appropriate restoration strategies on regulated rivers. This study focused on a 5.5 km long reach of the Morava River in the Strážnické Pomoraví region, Czech Republic that is characterised by quasi-natural evolution after substantial engineering adjustments were made in the first decades of the twentieth century. Based on Geographic Information Systems (GIS) analysis of aerial photographs, the spatio-temporal dynamics of bank erosion and accretion rates were quantitatively described and variables that control channel migration rates were identified. High rates of lateral shifts were localised in high sinuosity segments (sinuosity 1.17-2.37), whereas segments with very low rates were straight or formed into slightly curved bends (sinuosity 1.05-1.18). As a key factor, engineering works that influenced local river bed slope and induced a dramatic increase in bank erosion rates were identified. River engineering works induced a dramatic increase in bank erosion rate (2.19 m/year for 1938-53 and 1.47 m/year for 1953-63). An interval of approximately 25 years was needed before the erosion rates dropped back to values documented before river regulation (0.35-1.09 m/year for 1841-1938). Other important controlling variables included radius of curvature, frequency and magnitude of floods and, locally, river bank material properties and floodplain land cover.

  7. Meandering patterns in the wake of horizontal-axis wind and river turbines

    NASA Astrophysics Data System (ADS)

    Guala, Michele; Howard, Kevin; Singh, Arvind; Hill, Craig; Musa, Mirko; Feist, Christopher; Sotiropoulos, Fotis

    2014-11-01

    Energy harvesting devices with rotor axis oriented with the flow generate a wake which is unstable due to the complex interactions among turbulent structures from the incoming flow, root, hub and tip vortices (see Foti et al. APS/DFD 2014). Experiments in wind tunnel and open-channel flow with erodible surface show similar meandering patterns in the velocity field, which are responsible for the far wake expansion and the incoming turbulence experienced by down-wind/stream units. Wake meandering statistics were observed to depend on the operating turbine conditions (tip speed ratio), upstream device siting (turbine - turbine interaction) or specific turbine kinematics (floating turbine under waves). In addition, for wall boundary conditions defined by an erodible surface, where sand grains respond to local shear stress by moving (erosion) or settling (deposition), turbines were observed to induce dynamic topographic perturbations also exhibiting meandering patterns. This occurred in limited mobility conditions and under migrating bedforms, with large scale topographic features amplified under specific asymmetric turbine configurations. The work opens up the possibility to place turbines in complex flows optimizing their performance while maintaining, or reshaping, the surrounding topography by specific control or siting strategies. Resarch supported by NSF CAREER: CBET-1351303, IREE early career UMN, DOE Grant DE-EE0005482, NSF PFI Grant IIP-1318201.

  8. Sensitivity of Flow and Sediment Transport in Meandering Rivers to Scale Effects and Flow Rate

    SciTech Connect

    Shams, Mehrzad; Ahmadi, Goodarz; Smith, Duane H.

    2008-06-01

    Sensitivity of flow and sediment transport in a meandering river to variations in scaling and flow rate was studied. The FLUENT™ code was used for evaluating the river flow characteristics, including the mean velocity field and the Reynolds stress components, as well as for particle trajectory analysis. Particular attention was given to the sensitivity of the sedimentation patterns of different size particles in the river bend for various scales. Simulation studies were performed for both a model river and a physical river. The physical river was geometrically similar to the model river, with a scaling ratio of 1:100, but with identical Froude number. The flow and particle deposition patterns in the physical and model rivers were compared. It was shown that the mean flow quantities exhibit dynamic similarity, but the turbulence parameters and the particle sedimentation features in the physical river were different from the model. The secondary flows and particle transport patterns were also found to be sensitive to variation in the scale and flow rate.

  9. Lateral migration of the Middle Sacramento River, California

    USGS Publications Warehouse

    Brice, James Coble

    1977-01-01

    Rates and processes of lateral erosion were studied for the middle Sacramento River between Chico Landing and Colusa, Calif. , a river distance of about 50 miles which is bordered by valuable agricultural land. The study is based on comparison of maps made during 1867-1949 and on aerial photographs made during 1924-74. Meander loops migrate by downstream translation in a direction nearly perpendicular to the loop axis. Loops are cut off by straight or diagonal chutes across the meander neck. The sinuosity of the river has gradually decreased from a value of 1.56 in 1896 to 1.35 in 1974. The morphology and curvature of meander loops cut off before white settlers came to the area indicate that the river was more stable, as well as more sinuous , then than now; subsequent morphologic changes are attributed mainly to the clearing of riparian vegetation and the effects of levees in reducing the area of overflow. The bank-erosion is 1.82 acres per year per stream mile or about 15 feet per year per stream foot for the period 1896-1974. (Woodard-USGS)

  10. Impact of sedimentary heterogenities and sinuosity on river -aquifer exchanges in a meandering alluvial plain.

    NASA Astrophysics Data System (ADS)

    Rivière, A.; Maillot, M.; Weill, P.; Goblet, P.; Ors, F.

    2015-12-01

    A coupled sedimentary and hydrogeological model is used to quantify the impact of sedimentary heterogeneities and sinuosity on groundwater fluxes in an alluvial plain deposited by a meandering fluvial system. A 3D heterogeneous alluvial plain model is built with the stochastic/process-based model FLUMY, that simulates the evolution and the sedimentary processes of a meandering channel and its associated deposits. The resulting sedimentary blocks are translated in terms of hydrodynamic parameters (hydrofacies) and used in the 3D transient water transport model METIS. The simulated domain is 10 m-thick and at a pluri-kilometric horizontal scale, allowing considering several meanders. A head gradient between the upstream and downstream limits is imposed. The river is considered as a constant-head boundary that decreases linearly along the channel centerline. A zero-flux condition is prescribed on the other boundaries. Several cases are studied, including different degrees of sinuosity and different configurations of sediment heterogeneity: (i) a homogeneous sandy aquifer (ii) single mud-filled oxbow lake in a sandy porous media, (iii) several mud-filled oxbow lakes in a sandy porous media, and (iv) "fully" heterogeneous alluvial plain including fine-grained overbank deposits, sandy point bars, mudplugs and sandy crevasse plays. We quantify the exchange rates and directions between the river and the aquifer along the channel centerline, the piezometric evolution and the water residence time in the heterogeneous alluvial plain. This original method can improve our understanding of the functioning of alluvial corridors and evaluate the relevance of taking into account the structural heterogeneity of alluvial plains in larger regional hydrogeological models.

  11. Geophysical controls of aquifer-river exchange flow patterns in a UK lowland meandering river.

    NASA Astrophysics Data System (ADS)

    Dara, Rebwar; Krause, Stefan; Rivett, Michael

    2016-04-01

    The deposition of fine particles (clay and silt) and organic matters in alluvial sediments can substantially reduce the permeability of streambed sediments and extend towards the wider floodplain. The resulting hydraulic conductivity patterns within the streambed and floodplain have been shown to control both location as well as intensity of hyporheic exchange in many lowland rivers. The aim of the study is to investigate the variability in streambed permeability fields in an unprecedented spatial resolution and quantify the impacts on controlling hyporheic exchange fluxes in the River Tern, a UK lowland meandering stream. Geophysical surveys were conducted deploying Ground Penetrating Radar (GPR) in conjunction with geological information derived from core logs and bank exposures for mapping shallow subsurface structural heterogeneity. The GPR survey deployed a pulse EKKO pro equipped with a shielded 250 MHz antenna. For the floodplain survey, GPR profiles of 12 NE-SW and 6 NW- SE orientation profiles were taken creating a raster of approximately 10 m. The riparian terrestrial GPR surveys were accompanied by a longitudinal in channel GPR survey for which the antenna was deployed on a floating device. At locations identified to be representative for the range of streambed hydrofacies identified by GPR in investigated stream reach, multi-level mini-piezometer networks were installed in the streambed for monitoring groundwater-surface water exchange fluxes, and conducting dilution tracer tests for quantification of residence time distributions at the aquifer-river interface. Quasi-three-dimensional GPR profiles from closely spaced grids of 2D GPR data of floodplain deposits indicated a range of different radar facies and helped to delineate the type and extend of high and low conductive materials. The results of longitudinal GPR survey along a 240 m section of the river channel revealed that areas rich in low conductivity layers such as organic peat and clay lenses

  12. Tidal Meanders

    NASA Astrophysics Data System (ADS)

    Marani, M.; Lanzoni, S.; Zandolin, D.; Seminara, S.; Rinaldo, A.

    Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, to- pographic, vegetational and ecological features. New insight is provided on the ge- ometrical properties of tidal meanders, with possible dynamic implications on their evolution. In particular, it is shown that large spatial gradients of leading flow rates induce important spatial variabilities of meander wavelengths and widths, while their ratio remains remarkably constant in the range of scales of observation. This holds regardless of changes in width and wavelength up to two orders of magnitude. This suggests a locally adapted evolution, involving the morphological adjustment to the chief landforming events driven by local hydrodynamics. The spectral analysis of lo- cal curvatures reveals that Kinoshita's model curve does not fit tidal meanders due to the presence of even harmonics, in particular the second mode. Geometric parameters are constructed that are suitable to detect possible geomorphic signatures of the tran- sitions from ebb- to flood-dominated hydrodynamics, here related to the skewness of the tidal meander. Trends in skewness, however, prove elusive to measure and fail to show detectable patterns. We also study comparatively the spatial patterns of evolu- tion of the ratios of channel width to depth, and the ratio of width to local radius of curvature. Interestingly, the latter ratio exhibits consistency despite sharp differences in channel incision. Since the degree of incision, epitomized by the width-to-depth ratio, responds to the relevant erosion and migrations mechanisms and is much sen- sitive to vegetation and sediment properties, it is noticeable that we observe a great variety of landscape carving modes and yet recurrent planar features like constant width/curvature and wavelength/width ratios.

  13. Hydrological controls on the morphogenesis of low-energy meanders (Cher River, France)

    NASA Astrophysics Data System (ADS)

    Dépret, Thomas; Gautier, Emmanuèle; Hooke, Janet; Grancher, Delphine; Virmoux, Clément; Brunstein, Daniel

    2015-12-01

    River restoration is a key-issue for European hydrosystems that were modified over centuries by human activities. This is particularly true for numerous low energy rivers flowing in the plateaus of Western Europe. Because of this limited energy, their potential in terms of autogenic restoration a priori appears strongly restricted. This study examines the conditions under which the morphogenesis on one of these systems occurs in relation to various hydrologic conditions. Two complementary approaches are combined on three reaches of the meandering Cher River (France). Firstly, we examine at a pluri-decadal scale the control of duration, frequency and intensity of floods on the planimetric erosion (bank retreat mainly). Secondly, we estimate the range of effective discharge for bedload transport. The results show that the morphogenesis is controlled by low magnitude hydrological events. Two major controlling factors are suggested: low differential of energy between small and large floods, peculiar to low energy rivers of mid-latitude, and low critical discharges for lateral erosion and bedload mobilization. For these reasons, the ability of the alluvial Cher River to self-restore its fluvial dynamics seems to be relatively high.

  14. Channel dynamics and habitat complexity in a meandering, gravel-bed river

    NASA Astrophysics Data System (ADS)

    Harrison, L. R.; Legleiter, C. J.; Pecquerie, L.; Dunne, T.

    2009-12-01

    River channel dynamics play an important role in creating and maintaining diverse habitat conditions for multiple life stages of aquatic organisms. As a result, many river restoration projects seek to re-establish ecosystems in which an enhanced degree of habitat complexity is sustained through natural fluvial processes of flow, sediment transport, and channel change. Few field cases have effectively quantified the evolution of channel morphology and habitat complexity in restored rivers, however, and the outcomes of restoration actions remain difficult to predict. Our objective was to quantify the extent to which morphology, flow complexity and salmonid spawning and rearing habitat develop from the simplified initial conditions commonly observed in re-configured meandering channels. Using a time-series of topographic data, we measured rates of morphologic change in a recently restored gravel-bed reach of the Merced River, California, USA. We constructed two-dimensional (2D) hydrodynamic models to quantify how the evolving morphology influenced hydraulic conditions, flow complexity and suitability for Chinook salmon spawning and rearing. Following two large flood events, point bar development led to order-of-magnitude increases in modeled flow complexity, as quantified via the metrics of kinetic energy gradient, vorticity and hydraulic strain. On a bend-averaged scale, morphologic changes produced up to a two-fold increase in flow circulation, indicating a direct linkage between geomorphic processes and the development of habitat complexity at both the local (1.0 m2 grid cell) and meander wavelength scale. Habitat modeling indicated that the availability of Chinook salmon spawning habitat has increased over time, whereas the majority of the reach provides low-medium quality rearing habitat for juvenile salmonids, primarily due to a lack of low velocity refuge zones. These results demonstrate the ability of geomorphic processes to increase flow complexity and

  15. The performance of the Hydromorphological Index of Diversity (HMID) in a hydropower affected meandering river

    NASA Astrophysics Data System (ADS)

    Stähly, Severin; Bourqui, Pierre; Franca, Mario J.; Robinson, Christopher; Schleiss, Anton J.

    2016-04-01

    More than half of the Swiss electricity is produced by hydropower. Large price fluctuations cause severe hydropeaking flow regimes due to corresponding production fluctuations, which undisputedly have a negative impact on aquatic biota. Water diversion due to dams on the other hand imposes downstream residual flow regimes. The absence of flood events and regular sediment supply disrupts sediment dynamics and disconnects floodplains, which are habitats of high value, from its main channel. The residual-flow controlled reach at the Sarine river in western Switzerland is the subject of the present study. The Sarine meanders strongly and the river reach under analysis has a bed incision of locally more than 100 m. Its incision provokes the isolation of the river which is consequently minimally touched by human structures and shows a natural geomorphology. Since the construction of a dam upstream this reach in 1948, aiming at the water abstraction to hydropower, vegetation could establish and the active floodplain decreased its area, as airborne images show. Nevertheless, it is classified as a floodplain of national importance and it has been under protection since 1992. It is supposed to be a valuable habitat for a wide range of organisms. The Hydromorphological Index of Diversity (HMID) is a simple tool for quantifying the habitat richness in a river reach, taking into account the mean values and the variation of water depth and flow velocity. For channelized rivers, HMID values from up to 5 are expected, while morphological pristine sites with a high spatial variability of water depth and velocity show values of 9 or higher. For the residual flow of the Sarine River, flow depth and velocity were measured using ADCP and ADV. The results are compared with a nearby natural reference river and the outcome of a 2D numerical simulation. Finally, the behaviour and limitations of the HMID, in a hydropower affected river, are discussed. In the close future an artificial flood

  16. Estimating Net Bank Erosion Rates From the Floodplains of Meandering Rivers

    NASA Astrophysics Data System (ADS)

    Lauer, J. W.; Parker, G.

    2004-12-01

    Eroding streambanks are sometimes cited as net sources of sediment for rivers. If generally true, this presents an obvious mass balance problem: If rivers continually remove material from active floodplains without replacing all of it, then the floodplains should eventually disappear. For graded river/floodplain systems, then, deposition on the floodplain must, over the long term, balance what is eroded. However, there are at least two reasons why the net erosion due to bank migration, defined as the volume eroded from cut banks minus the volume deposited on point bars, should usually be positive. First, rivers generally migrate into natural levees that are somewhat higher in elevation than the rest of the floodplain. Since point bars are not built as high as natural levees, this represents a net loss of material from the floodplain. Second, river bends tend to migrate outwards, expanding over time. Since the eroding bank is invariably longer than the depositional bank, more material is eroded than deposited, even if the elevation at the top of both banks is constant. This leads to a steady increase in channel sinuosity over time until a cutoff occurs. For a floodplain that is in equilibrium, the erosion caused by natural levee recycling should be balanced primarily by overbank deposition, while the erosion caused by the systematic sinuosity increase should be balanced primarily by depositional processes in abandoned stream courses or oxbow lakes. Until now, it has not been clear which of the two processes is generally more important. This study presents a comparison of their relative importance, as well as system-wide net erosion rates, for portions of three U.S. rivers: a 91 km reach of the Pearl River in Louisiana, a 62 km reach of the Bogue Chitto River in Louisiana, and a 35 km reach of the Neuse River in North Carolina. The study is made possible by high resolution LIDAR datasets along these systems that represent the topography of the natural levees and

  17. Einstein's meanders

    NASA Astrophysics Data System (ADS)

    Lomnitz, C.

    2007-05-01

    What does Einstein have to do with subduction? Good question. Peaceful Lake Budi, lying at the heart of an Indian reservation in the Deep South of Chile, had subsided by two meters in the 1960 mega-thrust earthquake. This unique South American salt lake was hiding an awful secret: it was actually an oxbow, not a lake. But Einstein had realized in 1926 that meanders are natural freaks. Rivers will not flow uphill, yet - he claimed - they don't flow down the path of steepest descent either. This anomaly was put at the doorstep of a weak Coriolis Force. Thus Einstein problematized the dilemma of the earth sciences. How can a non-force produce margin-parallel compression in a convergent margin where extension is expected? In fact, where does the energy for meander formation come from? Good question . . . Even Wikipedia knows that Coriolis is not a “force” but an “effect”. So is the obliquity of plate convergence in subduction. Where did Einstein err, and where was he a pioneer? Coastal ablation plus alternating subsidence and emergence in giant earthquakes may yield an answer. Einstein, A. (1926). Die Ursache der Maeanderbildung der Flusslaeufe und das sogenannte Baersche Gesetz, Naturwissenschaften, 14, fascicle II.

  18. Geomorphic response of Lillooet River, British Columbia, to meander cutoffs and base level lowering

    NASA Astrophysics Data System (ADS)

    Weatherly, Hamish; Jakob, Matthias

    2014-07-01

    A detailed record of channel profiles, slopes, and stream discharge on Lillooet River provides an opportunity to study the effects of natural and artificial channel changes that have occurred over the past century. We analyze the long-term effects of channel alterations that may affect flood hazard. In the mid 1940s several meanders were artificially severed, side channels blocked off, and the level of downstream Lillooet Lake was lowered. These measures were thought to increase hydrologic efficiency and decrease flood risk in the largely agricultural valley. Between 1947 and 1994 average channel width in the upper reaches decreased by 50%, most of which occurred by the late 1950s. Between 1945 and 1969 Lillooet River degraded its bed elevation by 3-4 m (12.5 to 16.7 cm a- 1) in the upper reaches and up to 2 m (8.3 cm a- 1) in the lower reaches. This sudden and profound degradation compares to average bed elevation increases of 2.4 cm a- 1 prior to the engineering works. Between 1969 and 1985 the cross section area increased by 22% in the upper reaches and 13% in the lower reaches and decreased to 12% and 8%, respectively, for the time period 1985 to 2000. The increased sediment supply that was caused by channel straightening accelerated delta advance in Lillooet Lake from 7 m a- 1 (1858 to 1948) to 30 m a- 1 for the five-year period following the 1948 channel works. These rates have decreased over time, but with a current advance rate of 10.5 m a- 1 (1986-2009) are still above the long-term average prior to the channel changes. This study demonstrates the time scale, direction, and magnitude of channel changes following significant artificial river alterations. While the initial goal of decreasing flood risk had been achieved in the short term, the lower river apparently is slowly returning to an overall aggradational phase. Ongoing delta advance will ultimately increase channel elevations in the lower reaches and lead to significant flood hazards for populated

  19. Meander properties of Venusian channels

    NASA Technical Reports Server (NTRS)

    Komatsu, G.; Baker, V. R.

    1993-01-01

    Venusian lava channels have meander dimensions that relate to their mode of formation. Their meander properties generally follow terrestrial river trends of wavelength (L) to width (W) ratios, suggesting an equilibrium adjustment of channel form. Slightly higher L/W for many Venusian channels in comparison to terrestrial rivers may relate to nonaqueous flow processes. The unusually low L/W values for some Venusian and lunar sinuous rilles probably indicate modification of original meander patterns by lava-erosional channel widening.

  20. Earth meandering

    NASA Astrophysics Data System (ADS)

    Asadiyan, H.; Zamani, A.

    2009-04-01

    In this paper we try to put away current Global Tectonic Model to look the tectonic evolution of the earth from new point of view. Our new dynamic model is based on study of river meandering (RM) which infer new concept as Earth meandering(EM). In a universal gravitational field if we consider a clockwise spiral galaxy model rotate above Ninety East Ridge (geotectonic axis GA), this system with applying torsion field (likes geomagnetic field) in side direction from Rocky Mt. (west geotectonic pole WGP) to Tibetan plateau TP (east geotectonic pole EGP),it seems that pulled mass from WGP and pushed it in EGP due to it's rolling dynamics. According to this idea we see in topographic map that North America and Green land like a tongue pulled from Pacific mouth toward TP. Actually this system rolled or meander the earth over itself fractaly from small scale to big scale and what we see in the river meandering and Earth meandering are two faces of one coin. River transport water and sediments from high elevation to lower elevation and also in EM, mass transport from high altitude-Rocky Mt. to lower altitude Himalaya Mt. along 'S' shape geodetic line-optimum path which connect points from high altitude to lower altitude as kind of Euler Elastica(EE). These curves are responsible for mass spreading (source) and mass concentration (sink). In this regard, tiltness of earth spin axis plays an important role, 'S' are part of sigmoidal shape which formed due to intersection of Earth rolling with the Earth glob and actual feature of transform fault and river meandering. Longitudinal profile in mature rivers as a part of 'S' curve also is a kind of EE. 'S' which bound the whole earth is named S-1(S order 1) and cube corresponding to this which represent Earth fracturing in global scale named C-1(cube order 1 or side vergence cube SVC), C-1 is a biggest cycle of spiral polygon, so it is not completely closed and it has separation about diameter of C-7. Inside SVC we introduce cone

  1. A backwards-in-time Lagrangian framework for extraction of meander bend dynamics: use in meander classification, process diagnostics, and model comparison

    NASA Astrophysics Data System (ADS)

    Schwenk, J.; Lanzoni, S.; Foufoula-Georgiou, E.

    2013-12-01

    Physically based river meander migration models have grown in popularity and complexity since the pioneering work of Ikeda, Parker, and Saswe in 1981. Numerical meander models have proven valuable for understanding river meander dynamics by providing highly resolved temporal and spatial series of physiographic and morphodynamic properties that are difficult or impossible to observe from real meandering rivers. Analyses of such model outputs typically focus on either reachwide (e.g. sinuosity) or pointwise (e.g. local migration rates) measures. We propose here a framework that bridges the gap between holistic and reductionist approaches to river meandering. This research introduces a new method for identifying and tracking individual meanders ('atoms') from cutoff to inception. An atom is a river reach that evolves in time and eventually intersects itself to become an oxbow lake. Typically individual meander extractions use inflection points to demarcate meander end-points, but automated inflection detection is susceptible to spurious flexes along the centerline. We propose a different approach based on tracking cutoff nodes backwards in time thereby avoiding detection problems and making an atom's dynamics easily accessible. A classification scheme is developed that separates extracted atoms into three types of increasing complexity. Type I atoms are simple, single-loop meander bends; type II atoms contain complex, single-loop bends; and type III atoms consist of compound or multiple meanders. The distinct dynamic behavior of each atom type is explored through individual and ensemble dynamics, e.g. average growth rate, average migration rate, or statistics of local curvature series. Analyses reveal new insights that relate process and form and explore the effect of local versus non-local influences on meander growth. The utilized river migration model represents the most basic physical processes that drive river migration--i.e., channel cutoff and channel migration

  2. Fluvial Bank Erosion in the Meandering River Asker, UK: Insights from Computational Fluid Dynamics (CFD) Modelling

    NASA Astrophysics Data System (ADS)

    Darby, S. E.; Rinaldi, M.; Rossi Romanelli, L.; Spyropoulos, E.

    2003-12-01

    CFD simulations for a (200 m long) meander loop on the River Asker at Bridport in southern England. CFD models under specific steady (peak) flow conditions were developed using FLUENT, with peak flow discharge estimates obtained from an adjacent gauging station. The geometry of each model was specified using DEMs of the channel created from high-resolution tacheometric surveys of the study reach, with water surface elevation defined using a network of crest gauges spaced at 20 m intervals along the reach. Zero slip boundary conditions were defined at all sidewall nodes and initial flow velocity vectors at all nodes at the upstream inlet were estimated with reference to 3D flow velocity data acquired using Acoustic Doppler Velocimetry (ADV) at this location. Simulated flow fields for the extent of the study reach were then evaluated by comparing simulated and observed surface velocity vectors, the latter being derived from Particle Image Velocimetry (PIV), supplemented by ADV data in selected (accessible) locations. Finally, we use the near-bank boundary shear stress data obtained from the CFD models to develop insight into the nature and effectiveness of FE processes within the study reach.

  3. Applying a Model of Curvature-Driven Bend Migration Developed for Alluvial Rivers to a Gravel-Bedded River With Reaches of Exposed Bedrock

    NASA Astrophysics Data System (ADS)

    Narinesingh, P.; Pizzuto, J. E.

    2009-12-01

    The South River, Virginia, a sinuous, gravel-bedded river influenced by frequent bedrock exposures, appears at first glance to be meandering. However, when its planform statistics are compared to a freely meandering river (the Teklanika River, Alaska), systematic differences become apparent. Bends of the South River have shorter lengths, longer radii of curvatures, a distinctive meander wavelength spectrum, and a lower fractal dimension of D = 1.11 than those of the Teklanika River. Sixty five percent of the length of South River in the study area consists of sections with exposed bedrock (either on the bed or the banks) and islands. Alluvial floodplains of varying lengths are scattered between sections of bedrock and islands, accounting for the remaining 35% of the study reach. In these areas, the South River displays sinuosity values that may be as high as 2.5. Within the alluvial reaches, aerial photographs from 1937 and 2005 document significant channel migration. Driven by the need to quantify the flux of mercury-contaminated sediments entering the river through bank erosion, we applied the bend migration model of Johannesson and Parker (1989). The model, when schematized for hydraulics of the alluvial sections of the South River and calibrated to the total area of erosion mapped from aerial photographs, correctly predicts 45% of the observed locations of erosion as mapped from the aerial photographs and observed in the field. The total area of erosion computed using the predicted near-bank excess velocity is within 14% of that mapped. According to a non-parametric Kruskal-Wallis test, the predicted areas of erosion along the river are not significantly different from those defined by the historical aerial photographs (P >= 0.05, two tailed test). These results suggest that curvature dependent hydraulic models for alluvial rivers may provide useful predictions of total erosion of alluvium on mixed bedrock/alluvial rivers like the South River. However, improved

  4. Planform dynamics of meandering channels based on Wavelet analysis

    NASA Astrophysics Data System (ADS)

    Abad, J. D.

    2009-12-01

    Meandering rivers migrate along the floodplain describing upstream-, laterally, and downstream-valley bend orientations. The prediction of these features is still unresolved, therefore not allowing their direct integration into the river restoration framework. Abad and Garcia (2008a, b) investigated experimentally the implications of bend orientation (upstream- and downstream-valley) on hydrodynamics and bed morphodynamics of periodic asymmetric meandering channels. Downstream-valley bends produce a more coherent secondary flow and higher erosional power near the outer bank. Therefore, downstream oriented bends might migrate much faster than upstream oriented bends. Based on digital information of meandering planform dynamics, spectral analysis (Fast Fourier Transform, FFT) and wavelet analysis are carried out to describe the planform dynamics of meandering channels. Additional relevant parameters and observations based on these metrics (dominant modes along the planform configuration, location of oriented bends along the valley centerline, change of migration rate along the valley, among others) are also discussed in the present work. This work is relevant for river restoration such as the development of design criteria of in-stream structures taking into consideration not only hydraulic and morphologic parameters but also the impact of such structures on stream ecosystem.

  5. High precision terrestrial laser scanning : measuring the individual impact of floods and landslides on meandering bedrock river dynamics (Rangitikei river, New-Zealand)

    NASA Astrophysics Data System (ADS)

    Lague, D.; Bonnet, S.; Brodu, N.; Davies, T.; Leroux, J.

    2012-04-01

    Actively incising and meandering bedrock rivers are an ubiquitous feature of mountain belts, but the mechanisms leading to their formation and evolution are still poorly understood. Part of the problem lies in our limited ability to quantify in situ the mechanisms governing the dynamics of straight bedrock rivers (tool-cover effects, stochastic sediment supply and discharge effects, roughness effects,...). But the rapid and spatially variable rates of bank erosion in meanders also lead to potentially more complex hillslope-channel interactions than in straight river. Terrestrial laser scanner has the potential to shed new light on these interactions and to capture over large surfaces the impact of individual flood and landsliding events. Given the small changes of surface position that must be detected for even the largest rates of bedrock erosion (~ 5-10 mm/yr) and the 3D geometrical complexity of bedrock meanders, specific survey approaches and post-processing algorithms must be developed. To this end, we started to perform repeated Terrestrial Laser Scanner (TLS) surveys of actively incising meanders in the Rangitikei river (New-Zealand) in 2009. The Rangitikei river is incising weakly consolidated mudstone at an average rate of 5 mm/yr since 15 kyr and has developed a very sinuous meandering pattern with several cut-off bedrock meanders. Lateral undercutting of 100 m high cliffs generates failures of up to hundred of meters. Alluvial material consists of coarse resistant material (D50 ~20 cm) sourced from upstream, and large boulders locally derived from rockfalls. Exposed bedrock is rare on the bed but shows that abrasion, weathering by wetting-drying cycles and plucking are important incision mechanisms. Six TLS surveys were performed at bi-monthly to yearly intervals with a Leica Scanstation 2 in 5 reaches of variable planform curvature. Survey length varies from 300 m to 1200 m and point spacing from ~ 5 mm to 5 cm. Point clouds were co-registered between

  6. Meandering channels without vegetation: Examples from Nevada and Chile

    NASA Astrophysics Data System (ADS)

    Matsubara, Y.; Howard, A. D.; Burr, D. M.; Williams, R. M.; Moore, J. M.

    2012-12-01

    We report on a study motivated by the occurrence of highly sinuous, actively migrating paleochannels on Mars. Highly sinuous, unconfined meanders require small aspect ratios, which in turn require cohesive channel banks. This cohesion is obtained most commonly by vegetation cover coupled with high suspended sediment loading. The dominant role of vegetation in meandering is reflected in the difficulty in creating highly sinuous channels in flume experiment without introduction of vegetation. The occurrence of strongly meandering channels on Mars suggests meanders can develop in the absence of vegetation. The main objective of our study is to understand the processes of meander evolution in non-vegetated surfaces. We have studied two terrestrial sites in which meandering channels form where vegetation is sparse and has little influence on bank erodibility or point-bar deposition, indicating that there must be other mechanisms creating bank cohesion. One mechanism is stabilization of point-bar deposits by mud drapes. The Quinn River in Nevada is a sinuous channel that flows through fine lacustrine sediments on the floor of paleolake Lahontan resulting in the river having both bed and bank composed of sediment containing least 40% silt/clay. In addition to abundant mud, high salt content of the river water encourages flocculation and settling of fine sediment; thus both high clay/silt content and salt work together at the Quinn River to maintain a small aspect ratio. In contrast to the Quinn River, meandering channels on alluvial fans in the Atacama Desert in northern Chile are deposited by flows originating from the foothills of the Andes Mountains where sediments are coarser and more variable in size. Like Quinn River both fine sediments and salts contribute to meandering. The bank cohesion is provided by mudflows or hyperconcentrated flows creating bank drapes as well as extensive overbank levees which harden to adobe-like consistency. The Atacama Desert is rich in

  7. Geomorphic adjustment to hydrologic modifications along a meandering river: Implications for surface flooding on a floodplain

    NASA Astrophysics Data System (ADS)

    Edwards, Brandon L.; Keim, Richard F.; Johnson, Erin L.; Hupp, Cliff R.; Marre, Saraline; King, Sammy L.

    2016-09-01

    Responses of large regulated rivers to contemporary changes in base level are not well understood. We used field measurements and historical analysis of air photos and topographic maps to identify geomorphic trends of the lower White River, Arkansas, USA, in the 70 years following base-level lowering at its confluence with the Mississippi River and concurrent with flood control by dams. Incision was identified below a knickpoint area upstream of St. Charles, AR, and increases over the lowermost ~90 km of the study site to ~2 m near the confluence with the Mississippi River. Mean bankfull width increased by 30 m (21%) from 1930 to 2010. Bank widening appears to be the result of flow regulation above the incision knickpoint and concomitant with incision below the knickpoint. Hydraulic modeling indicated that geomorphic adjustments likely reduced flooding by 58% during frequent floods in the incised, lowermost floodplain affected by backwater flooding from the Mississippi River and by 22% above the knickpoint area. Dominance of backwater flooding in the incised reach indicates that incision is more important than flood control on the lower White River in altering flooding and also suggests that the Mississippi River may be the dominant control in shaping the lower floodplain. Overall, results highlight the complex geomorphic adjustment in large river-floodplain systems in response to anthropogenic modifications and their implications, including reduced river-floodplain connectivity.

  8. Floodplain architecture of an actively meandering river (the Ploučnice River, the Czech Republic) as revealed by the distribution of pollution and electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Matys Grygar, T.; Elznicová, J.; Tůmová, Š.; Faměra, M.; Balogh, M.; Kiss, T.

    2016-02-01

    The aim of this study was to describe the floodplain architecture of the Ploučnice River, a naturally meandering river in the Czech Republic, using manual drill coring, the element analysis of sediments, and electrical resistivity tomography (ERT). The Ploučnice River has received diffuse pollution since the early twentieth century (mainly Pb) followed by a prominent, temporally well-defined pollution pulse from uranium mining in the 1970s and 1980s (mainly U and 226Ra). The pollution created a chemostratigraphic (temporal) framework for overbank fines. We used geographical information systems (GIS) to describe the channel's dynamics and visualise fluvial landforms. We sampled and analysed the finest floodplain sediments in the top 1 to 2 m of the floodplain fill (silty and sandy deposits), and we used ERT to visualise bodies of coarser and deeper strata at depths down to ~ 3 m. Several limits of ERT imaging have been found by a comparison of the resistivity domains with lithological descriptions of the cores: several decimetre-thick strata were not revealed (they are below the spatial resolution of that method), and humidity affected the results that were obtained in the topmost strata. The space for deposition of fluvial sediments in the Ploučnice River is being created by (1) natural lateral shifts in the channel (up to 0.5 m/year); (2) meander loop development and cutoffs at the timescale of decades to centuries and spatial scale of up to ~ 1/4 of the floodplain width; and (3) more substantial reorganisation of the channel structure by avulsions, probably at the timescale of centuries. These processes continuously create space for the deposition of overbank fines on the top of former point bars and in swales and abandoned channels. As a consequence of the speed of the channel shifts, at least 80% of the fine-grained top of the floodplain fill (overbank fines) was reworked over approximately three centuries.

  9. From meander bend to oxbow lake: flow, channel morphology and sedimentology of an evolving chute cutoff on the Wabash River, IL-IN

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J. L.; Johnson, K.

    2012-12-01

    Chute channels develop on meandering rivers in a wide variety of environments, and in many cases result in bend cutoff and formation of an oxbow lake. During the transition from active meander bend to oxbow lake, the chute channel and original bend create a paired bifurcation-confluence unit. Here, we present field documentation of the evolving flow structure within a recent chute cutoff on the Wabash River, IL-IN, focusing on the bifurcation located on the upstream limb of the original bend. Previous studies indicate that this is the location of greatest sedimentation rates prior to complete plugging of the bend (e.g. Shields & Abt, 1989). We seek to isolate the fundamental processes causing rapid sedimentation in the upstream limb of the bend, using repeated hydroacoustic measurements of bed elevation and three-dimensional flow velocity at several key cross-sections. We also employ differential GPS surveys of channel banklines, analysis of aerial photographs and sampling of sediment on exposed bars at low flow, to aid interpretations of the cross-sectional data. This paper will detail the co-evolution of flow structure and channel morphology at this site and examine the coherent patterns of erosion and deposition responsible for oxbow lake formation. Reference: Shields, FD; Abt, SR (1989). Sediment deposition in cutoff meander bends and implications for effective management. Regulated Rivers: Research & Management 4, 381-396.

  10. Flow structure and channel morphodynamics of meander bend chute cutoffs: A case study of the Wabash River, USA

    NASA Astrophysics Data System (ADS)

    Zinger, Jessica A.; Rhoads, Bruce L.; Best, James L.; Johnson, Kevin K.

    2013-12-01

    paper documents the three-dimensional structure of flow and bed morphology of two developing chute cutoffs on a single meander bend on the lower Wabash River, USA, and relates the flow structure to patterns of morphologic change in the evolving cutoff channels. The upstream end of the cutoff channels is characterized by: (1) a zone of flow velocity reduction/stagnation and bar development in the main channel across from the cutoff entrance, (2) flow separation and bar development along the inner (left) bank of the cutoff channel immediately downstream from the cutoff entrance, and (3) helical motion and outward advection of flow momentum entering the cutoff channel, leading to erosion of the outer (right) bank of the cutoff channel. At the downstream end of the cutoff channels, the major hydrodynamic and morphologic features are: (1) flow stagnation along the bank of the main channel immediately upstream of the cutoff channel mouth, (2) convergence of flows from the cutoff and main channels, (3) helical motion of flow from the cutoff, (4) a zone of reduced velocity along the bank of the main channel immediately downstream from the cutoff channel mouth, and (5) development of a prominent bar complex that penetrates into the main channel and extends from the stagnation zone upstream to downstream of the cutoff mouth. These results provide the basis for a conceptual model of chute-cutoff dynamics in which the upstream and downstream ends of a cutoff channel are treated as a bifurcation and confluence, respectively.

  11. Spatial variability in bank resistance to erosion on a large meandering, mixed bedrock-alluvial river

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial heterogeneities of the erosion-resistance properties of the channel banks and floodplains, such as grain size characteristics and the presence of vegetation and bedrock, can have a substantial influence on river morphodynamics, resulting in complex planform geometries and highly variable rat...

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

    NASA Astrophysics Data System (ADS)

    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.

    2012-12-01

    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

  13. The life of a meander bend: Connecting shape and dynamics via analysis of a numerical model

    NASA Astrophysics Data System (ADS)

    Schwenk, Jon; Lanzoni, Stefano; Foufoula-Georgiou, Efi

    2015-04-01

    Analysis of bend-scale meandering river dynamics is a problem of theoretical and practical interest. This work introduces a method for extracting and analyzing the history of individual meander bends from inception until cutoff (called "atoms") by tracking backward through time the set of two cutoff nodes in numerical meander migration models. Application of this method to a simplified yet physically based model provides access to previously unavailable bend-scale meander dynamics over long times and at high temporal resolutions. We find that before cutoffs, the intrinsic model dynamics invariably simulate a prototypical cutoff atom shape we dub simple. Once perturbations from cutoffs occur, two other archetypal cutoff planform shapes emerge called long and round that are distinguished by a stretching along their long and perpendicular axes, respectively. Three measures of meander migration—growth rate, average migration rate, and centroid migration rate—are introduced to capture the dynamic lives of individual bends and reveal that similar cutoff atom geometries share similar dynamic histories. Specifically, through the lens of the three shape types, simples are seen to have the highest growth and average migration rates, followed by rounds, and finally longs. Using the maximum average migration rate as a metric describing an atom's dynamic past, we show a strong connection between it and two metrics of cutoff geometry. This result suggests both that early formative dynamics may be inferred from static cutoff planforms and that there exists a critical period early in a meander bend's life when its dynamic trajectory is most sensitive to cutoff perturbations. An example of how these results could be applied to Mississippi River oxbow lakes with unknown historic dynamics is shown. The results characterize the underlying model and provide a framework for comparisons against more complex models and observed dynamics.

  14. Computer simulations of channel meandering and the formation of point bars: Linking channel dynamics to the preserved stratigraphy

    NASA Astrophysics Data System (ADS)

    Sun, T.; Covault, J. A.; Pyrcz, M.; Sullivan, M.

    2012-12-01

    Meandering rivers are probably one of the most recognizable geomorphic features on earth. As they meander across alluvial and delta plains, channels migrate laterally and develop point bars, splays, levees and other geomorphic and sedimentary features that compose substantial portions of the fill within many sedimentary basins. These basins can include hydrocarbon producing fields. Therefore, a good understanding of the processes of meandering channels and their associated deposits is critical for exploiting these reservoirs in the subsurface. In the past couple of decades, significant progress has been made in our understanding of the morphodynamics of channel meandering. Basic fluid dynamics and sediment transport (Ikeda and Parker, 1981; Howard, 1992) has shown that many characteristic features of meandering rivers, such as the meandering wavelength, growth rate and downstream migration rate, can be predicted quantitatively. As a result, a number of variations and improvement of the theory have emerged (e.g., Blondeaux and Seminara, 1985; Parker and Andrews, 1985, 1986; and Sun et al., 2001a, b).The main improvements include the recognition of so called "bar-bend" interactions, where the development of bars on the channel bed and their interactions with the channel bend is recognized as a primary cause for meandering channels to develop greater complexity than the classic goose-neck meander bend shapes, such as compound bend. Recently, Sun and others have shown that the spatial patterns of width variations in meandering channels can be explained by an extrinsic periodic flow variations coupled with the intrinsic bend instability dynamics. In contrast to the significant improvement of our understanding of channel meandering, little work has been done to link the geomorphic features of meandering channels to the geometry and heterogeneity of the deposits they form and ultimately preserves. A computer simulation model based on the work of Sun and others (1996, 2001

  15. Neotectonic effects on sinuosity and channel migration, Belle Fourche River, Western South Dakota

    USGS Publications Warehouse

    Gomez, Basil; Marron, Donna C.

    1991-01-01

    Short-term instability in the behaviour of a small, meandering alluvial channel is identified from the relation between sinuosity and either floodplain slope or channel slope within 17 reaches along an 81-kilometre section of the Belle Fourche River in western South Dakota. In reaches 1 to 4 and 11 to 17 the channel is relatively stable and sinuosity varies inversely with channel slope. In reaches 5 to 10, sinuosity is positively related to floodplain slope. Sinuosity increases markedly in reaches 5, 6, and 7 (which are immediately downstream from a discontinuity in the long profile of the floodplain) in association with an increase in floodplain slope. Immediately upstream from the discontinuity, bankfull channel depth and sinuosity decrease and the area of the floodplain reworked by meander migration between 1939 and 1981 increases, in association with a decrease in floodplain slope. Channel behaviour in reaches 5 to 10 is best explained as a consequence of neotectonic activity, as indicated by changes in elevation recorded along geodetic survey lines that cross lineaments that may delimit the eastern boundary of the Black Hills uplift. Sinuosity acts as a barometer of the effects of neotectonic activity on alluvial channels. Initial indications of channel and floodplain instability due to neotectonic activity may be derived from evidence of anomalously active channel migration, as documented from photographic or topographic sources.

  16. Numerical modeling of erosional and depositional bank processes in migrating river bends with self-formed width: Morphodynamics of bar push and bank pull

    NASA Astrophysics Data System (ADS)

    Eke, Esther; Parker, Gary; Shimizu, Yasuyuki

    2014-07-01

    Meandering rivers display active communication between bank erosion and bar deposition processes. How does this occur? How does the river select its width? To answer these questions, we implement a model for meander migration where both bank processes (erosion and deposition) are considered independently. Bank erosion is modeled as erosion of purely noncohesive bank material damped by natural slump block armoring; channel deposition is modeled via flow-retarded vegetal encroachment. Both processes are tied to a slope-dependent channel forming Shields number; banks with near-bank Shields number below this value undergo deposition, and those above it undergo erosion. Channel-forming Shields number must increase with slope, as dictated by available data and model performance. Straight channel modeling shows that a channel arrives at an equilibrium width from any initial condition. For the channel bend, the river always approaches an asymptotic state where width reduces slowly in time and where bank erosion and deposition occur at nearly equal rates. Before this state is reached, however, the river follows a phase-plane trajectory with four possible regimes: (a) both banks erode, (b) both banks deposit, (c) both banks migrate outward, but with a faster depositing bank (bar push), and (d) both banks migrate outward, but with a faster eroding bank (bank pull). The trajectory of migration on the phase plane depends on initial conditions and input parameters controlling the rate of depositional and erosional migration. All input parameters have specific physical meaning, and the potential to be measured in the field.

  17. Analysing the meandering rivers responses to the slope-changes, depending on their bankfull discharge - Case study in the Pannonian Basin

    NASA Astrophysics Data System (ADS)

    Petrovszki, Judit; Timár, Gábor; Molnár, Gábor

    2014-05-01

    The multi-variable connection between the channel slope, bankfull discharge and sinuosity values were analysed to get a mathematical formula, which describes the responses of the rivers, and gives the probable sinuosity values for every slope and discharge values. Timár (2003) merged two planar diagrams into a quasi 3D graph. One of them displayed how the river pattern changes, according to the slope and bankfull discharge values (Leopold and Wolmann, 1957; Ackers and Charlton, 1971); the other based on flume experiments, and gives a connection between the slope and sinuosity (Schumm and Khan, 1972). The result graph suggests that the slope-sinuosity connection also works along the natural rivers, for every discharge values. The aim of this work was to prove this relation, and describe it numerically. The sinuosity values were calculated along the natural, meandering river beds, using historical maps (2nd Military Survey of the Habsburg Empire, from the 19th century). The available slope and discharge values were imported from a database measured after the main river control works, at the beginning of the 20th century (Viczián, 1905). Analysing the reports of the river control works, the natural slope could be computed for every river sections. The mean discharges were also converted to bankfull discharges. Neither long time series, nor cross sectional areas were obtainable, so other method was used to generate the bankfull discharge. After the above mentioned corrections a quadratic polynomial surface was fitted onto these points with least squares regression. The cross section of this surface follows the theoretical slope-sinuosity graph, verifying that the flume experiments and natural rivers behave similarly. The differences between the fitted surface and the original points were caused by other river parameters, which also affect the natural rivers (e.g. the sediment discharge). Furthermore, this graph confirms the connection between the slope and sinuosity

  18. Characterizing and modelling river channel migration rates at a regional scale: Case study of south-east France.

    PubMed

    Alber, Adrien; Piégay, Hervé

    2016-11-23

    An increased awareness by river managers of the importance of river channel migration to sediment dynamics, habitat complexity and other ecosystem functions has led to an advance in the science and practice of identifying, protecting or restoring specific erodible corridors across which rivers are free to migrate. One current challenge is the application of these watershed-specific goals at the regional planning scales (e.g., the European Water Framework Directive). This study provides a GIS-based spatial analysis of the channel migration rates at the regional-scale. As a case study, 99 reaches were sampled in the French part of the Rhône Basin and nearby tributaries of the Mediterranean Sea (111,300 km(2)). We explored the spatial correlation between the channel migration rate and a set of simple variables (e.g., watershed area, channel slope, stream power, active channel width). We found that the spatial variability of the channel migration rates was primary explained by the gross stream power (R(2) = 0.48) and more surprisingly by the active channel width scaled by the watershed area. The relationship between the absolute migration rate and the gross stream power is generally consistent with the published empirical models for freely meandering rivers, whereas it is less significant for the multi-thread reaches. The discussion focused on methodological constraints for a regional-scale modelling of the migration rates, and the interpretation of the empirical models. We hypothesize that the active channel width scaled by the watershed area is a surrogate for the sediment supply which may be a more critical factor than the bank resistance for explaining the regional-scale variability of the migration rates.

  19. 2D and 3D numerical simulations of morphodynamics structures in a large-amplitude meanders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the pioneering study of the Ishikari River, Japan, Kinoshita (Kinoshita 1957, 1961) described two types of meandering channels: (1) channel with two bars per meander wavelength (one bar per bend), and (2) channel with three or more bars per meander wavelength (multiple bars per bend). Based on th...

  20. Savannah River Site computing architecture migration guide

    SciTech Connect

    Not Available

    1991-07-30

    The SRS Computing Architecture is a vision statement for site computing which enumerates the strategies which will guide SRS computing efforts for the 1990s. Each strategy is supported by a number of feature statements which clarify the strategy by providing additional detail. Since it is a strategic planning document, the Architecture has sitewide applicability and endorsement but does not attempt to specify implementation details. It does, however, specify that a document will be developed to guide the migration from the current site environment to that envisioned by the new architecture. The goal of this document, the SRS Computing Architecture Migration Guide, is to identify specific strategic and tactical tasks which would have to be completed to fully implement the architectural vision for site computing as well as a recommended sequence and timeframe for addressing these tasks. It takes into account the expected availability of technology, the existing installed base, and interdependencies among architectural components and objectives.

  1. Spatiotemporal Dynamics of River Channel Migration on the Ganges-Brahmaputra Delta: 2000-2013

    NASA Astrophysics Data System (ADS)

    Small, C.; Chiu, S.; Sousa, D.; Mondal, D. R.; Steckler, M. S.; Akhter, S. H.; Mia, B.; Goodbred, S. L., Jr.; Wilson, C.; Seeber, L.

    2014-12-01

    downstream migration of the larger meanders on both rivers. We also observe a pronounced change in the morphology and evolution of the channels in the Brahmaputra braid plain upstream and downstream of the hinge zone with more rapid changes in channel geometry upstream and a more stable configuration of two anastamosing primary channels downstream.

  2. Optimum swimming pathways of fish spawning migrations in rivers

    USGS Publications Warehouse

    McElroy, Brandon; DeLonay, Aaron; Jacobson, Robert

    2012-01-01

    Fishes that swim upstream in rivers to spawn must navigate complex fluvial velocity fields to arrive at their ultimate locations. One hypothesis with substantial implications is that fish traverse pathways that minimize their energy expenditure during migration. Here we present the methodological and theoretical developments necessary to test this and similar hypotheses. First, a cost function is derived for upstream migration that relates work done by a fish to swimming drag. The energetic cost scales with the cube of a fish's relative velocity integrated along its path. By normalizing to the energy requirements of holding a position in the slowest waters at the path's origin, a cost function is derived that depends only on the physical environment and not on specifics of individual fish. Then, as an example, we demonstrate the analysis of a migration pathway of a telemetrically tracked pallid sturgeon (Scaphirhynchus albus) in the Missouri River (USA). The actual pathway cost is lower than 105 random paths through the surveyed reach and is consistent with the optimization hypothesis. The implication—subject to more extensive validation—is that reproductive success in managed rivers could be increased through manipulation of reservoir releases or channel morphology to increase abundance of lower-cost migration pathways.

  3. Optimum Pathways of Fish Spawning Migrations in Rivers

    NASA Astrophysics Data System (ADS)

    McElroy, B. J.; Jacobson, R. B.; Delonay, A.

    2010-12-01

    Many fish species migrate large distances upstream in rivers to spawn. These migrations require energetic expenditures that are inversely related to fecundity of spawners. Here we present the theory necessary to quantify relative energetic requirements of upstream migration pathways and then test the hypothesis that least-cost paths are taken by the federally endangered pallid sturgeon (Scaphyrhyncus Albus), a benthic rheophile, in the lower Missouri River, USA. Total work done by a fish through a migratory path is proportional to the size of the fish, the total drag on the fish, and the distance traversed. Normalizing by the work required to remain stationary at the beginning of a path, relative work expenditure at each point of the path is found to be the cube of the ratio of the velocity along the path to the velocity at the start of the path. This is the velocity of the fish relative to the river flow. A least-cost migratory pathway can be determined from the velocity field in a reach as the path that minimizes a fish's relative work expenditure. We combine location data from pallid sturgeon implanted with telemetric tags and pressure-sensitive data storage tags with depth and velocity data collected with an acoustic Doppler profiler. During spring 2010 individual sturgeon were closely followed as they migrated up the Missouri River to spawn. These show that, within a small margin, pallid sturgeon in the lower Missouri River select least-cost paths as they swim upstream (typical velocities near 1.0 - 1.2 m/s). Within the range of collected data, it is also seen that many alternative paths not selected for migration are two orders of magnitude more energetically expensive (typical velocities near 2.0 - 2.5 m/s). In general these sturgeon migrated along the inner banks of bends avoiding high velocities in the thalweg, crossing the channel where the thalweg crosses in the opposite direction in order to proceed up the inner bank of subsequent bends. Overall, these

  4. Meander applications at landslides in alluvium valleys

    NASA Astrophysics Data System (ADS)

    Yilmaz, L.

    2012-04-01

    For calculation of bed variation in alluvial channels important bed configurations include meso-scale bed configurations, such as alternating bars (pools and riffles) and braided bars. It is important in river management to be able to predict water surface elevation, scour, and fill in alluvial channels under given flow conditions. Mathematical and physical models can be used in designing or planning for improvement of river channels and hydraulic structures. Several studies have been made to evaluate flow and bed variation in meandering channels (Engelund, 1974; Odgaard, 1986; Ikeda et al., 1987; Falcon and Kennedy, 1983; Kishi et al., 1983, Struiksma, 1985, and Struiksma et al., 1985). The bed variation at meandering channels is calculated by the continuity equation for bed load transport. Typical bed configurations and flows with alternating bars and braided bars are produced in straight channels, and thus the formation and migration of bars are predicted quantitatively. The results of model applications were carried out for the same situations as the mathematical model at the Technical University of Berlin, Institute Wasserbau and Wasserwirtschaft (Yilmaz, 1990), started with flat bed, continued until dz/ dt=0. Then the beds were solidified, and precise measurements of the bed configuration and the velocity were performed. Plan geometries of runs consist of a sine-generated curve and an asymmetrical meander loop, respectively. The latter is derived by a Fourier series analysis on several typical bends. The meso-scale bed configuration in alluvial streams is highly dependent on the width-depth ratio of the channel. The velocity measurements were made with small mechanical current meters fixed to a 1m high frame that rested on the bottom while measuring the lower points on the profile. The frame was suspended at different levels above the bottom to collect the data represented by the higher points. Velocity profiles are plotted semi-logarithmically with the dots

  5. [Ethnic dimension to migration in the Senegal river valley].

    PubMed

    Traore, S

    1993-08-01

    Studies of the factors determining migratory patterns in the Senegal River Valley usually stress the importance of economic factors related to colonial domination. But when cultural factors and the social relations governing them are examined in a comparative study of ethnic groups, distinct population subgroups may be revealed to have differential migratory patterns. The Soninka and the Poular, two groups highly affected by migration, were chosen for an analysis of the impact of specific historical experiences on migratory behavior. A historical analysis of colonial archives and anthropological and historical monographs and the 1982-83 "Survey of Migration in the Valley of the Senegal River" provided data. The survey indicated that Soninka and Poular migratory patterns differed from each other, but that both differed from the migratory patterns of all other ethnic groups in the region. Soninka migration is international and oriented primarily toward Europe. It has recently become more intense than that of the poular. The determinants of migration in the two groups appear related more to the structure of households than to lack of educational and health facilities or even of food at the village level. Pastoral life and its associated beliefs and religious ideology appear to have been the principal determinants of precolonial movement among the Poular, while Soninka migration responded more to competition over control of manpower. Itinerant commercial activity was coupled with use of slave labor to ensure food production. But the suppression of slavery and crises of subsistence aggravated by colonial policy provoked ever more distant migration, which found a focus in the French demand for labor after World War II. Migration as an alternative does not appear to have been as significant for the Poular until more recently, when subsistence agriculture and the sale of animals were no longer sufficient to cover monetary needs. Male migration among the Soninka is a

  6. Meandering Brownian Donkeys

    NASA Astrophysics Data System (ADS)

    Eichhorn, R.; Reimann, P.

    2004-04-01

    We consider a Brownian particle whose motion is confined to a ``meandering'' pathway and which is driven away from thermal equilibrium by an alternating external force. This system exhibits absolute negative mobility, i.e. when an external static force is applied the particle moves in the direction opposite to that force. We reveal the physical mechanism behind this ``donkey-like'' behavior, and derive analytical approximations that are in excellent agreement with numerical results.

  7. Potamodromous migrations in the Magdalena River basin: bimodal reproductive patterns in neotropical rivers.

    PubMed

    López-Casas, S; Jiménez-Segura, L F; Agostinho, A A; Pérez, C M

    2016-07-01

    Magdalena River basin potamodromous fishes have two annual reproductive seasons: the subienda in the first half of the year and the mitaca in the second. Both upstream migrations are c. 30-45 days long; after that, with the onset of the rainy season, fishes spawn and remain in the river (resident individuals) or start a downstream movement (the bajanza) to return to the Magdalena floodplain lakes (nursery, shelter and feeding grounds). Due to their particular gonad development the bocachico Prochilodus magdalenae and probably the comelón Leporinus muyscorum are physiologically able to undertake two annual basin migrations. In the presence of dams or hydropower structures, fishes are able to find alternative migration routes. Some species should be re-classified in their migratory behaviour.

  8. Downstream-migrating fluvial point bars in the rock record

    NASA Astrophysics Data System (ADS)

    Ghinassi, Massimiliano; Ielpi, Alessandro; Aldinucci, Mauro; Fustic, Milovan

    2016-04-01

    Classical models developed for ancient fluvial point bars are based on the assumption that meander bends invariably increase their radius as meander-bend apices migrate in a direction transverse to the channel-belt axis (i.e., meander bend expansion). However, many modern meandering rivers are also characterized by down-valley migration of the bend apex, a mechanism that takes place without a significant change in meander radius and wavelength. Downstream-migrating fluvial point bars (DMFPB) are the dominant architectural element of these types of meander belts. Yet they are poorly known from ancient fluvial-channel belts, since their disambiguation from expansional point bars often requires fully-3D perspectives. This study aims to review DMFPB deposits spanning in age from Devonian to Holocene, and to discuss their main architectural and sedimentological features from published outcrop, borehole and 3D-seismic datasets. Fluvial successions hosting DMFPB mainly accumulated in low accommodation conditions, where channel belts were affected by different degrees of morphological (e.g., valleys) or tectonic (e.g., axial drainage of shortening basins) confinement. In confined settings, bends migrate downstream along the erosion-resistant valley flanks and little or no floodplain deposits are preserved. Progressive floor aggradation (e.g., valley filling) allow meander belts with DMFPB to decrease their degree of confinement. In less confined settings, meander bends migrate downstream mainly after impinging against older, erosion-resistant channel fill mud. By contrast, tectonic confinement is commonly associated with uplifted alluvial plains that prevented meander-bend expansion, in turn triggering downstream translation. At the scale of individual point bars, translational morphodynamics promote the preservation of downstream-bar deposits, whereas the coarser-grained upstream and central beds are less frequently preserved. However, enhanced preservation of upstream

  9. Seasonal migration of Gulf sturgeon in the Suwannee River, Florida

    USGS Publications Warehouse

    Foster, A.M.; Clugston, J.P.

    1997-01-01

    The movements of 67 Gulf sturgeon Acipenser oxyrinchus desotoi equipped with radio transmitters were monitored in the Suwannee River, Florida, from March 1989 through August 1992. The objectives of this study were (1) to determine the seasonal movement patterns and distribution of Gulf sturgeon while in freshwater, (2) to document relationships between water temperature and Gulf sturgeon movement, and (3) to determine whether springs were used as thermal refugia by these fish. Gulf sturgeon were detected entering the river from mid-February through April; they moved upstream at an average speed of 3.5 km/d to areas where they remained until October or November. Gulf sturgeon moved no more than 0,6 river km (on average) upstream or downstream from their established summer area. Gulf sturgeon began leaving the Suwannee River from mid-September through early November and moved downstream at an average speed of 6.2 km/d; all fish returned to the Gulf of Mexico by early December. Water temperatures associated with spring and fall migrations averaged 22.1 ??C (range, 16.0-28.0??C) and 21.3??C (range, 16.9-26.8??C), respectively. Gulf sturgeon were frequently close to springs throughout the warmest period, but none were located within a spring or the thermal plume emanating from a spring.

  10. Water surface and channel bed morphology change before and after a laboratory meander neck cutoff

    NASA Astrophysics Data System (ADS)

    Han, B.; Endreny, T. A.

    2012-12-01

    Meander evolution of narrowing point bars ultimately forms a straight reach and an associated oxbow lake after meand bend cutoff. Observing the water surface and bed topography change during the meander cutoff process allows scientists and engineers to better understand flow mechanisms in meandering rivers, predict river behavior following cutoff, and minimize damage to life and property. Theoretical river evolution model indicates that head loss between the upstream and downstream meander neck increases during meander evolution, and this leads to an increasing hydraulic gradient and intensification of the cutoff. Yet no detailed observations are available to support the theory. In this research, we establish a physical model of a meander cutoff in a 1.8 m * 3.7 m laboratory river table using 0.18 mm median diameter sand and river discharge of 100 mL/s. The initial meander is a highly curved meander with a sinuosity of 5.6. Erosion is initiated by stream flow and the meander goes through the cutoff process. Water surface elevation along the river, river bed topography, and groundwater head in the intra-meander zone are precisely measured with an accuracy of up to 0.4 mm using a close range photogrammetry technique and ultrasonic sensors. The measurements are taken every 5 hours before the cutoff, immediately after the cutoff, and 1 hour, 5 hours after the cutoff respectively. Our results show that hydraulic gradient gradually steepens crossing the meander neck before the cutoff. River bed elevation gradients crossing the meander neck are enlarged due to the continuous deposition at the upstream neck and erosion at the downstream neck. However, the river bed elevation differences is counter balanced by the water depth which is smaller at the upstream and larger at the downstream, and the head loss across the neck remains nearly the same during cutoff. Immediately after the meander cutoff, a cascade emerges, and then rapidly dissipates into the new channel during

  11. Were rivers flowing across the Sahara during the last interglacial? Implications for human migration through Africa.

    PubMed

    Coulthard, Tom J; Ramirez, Jorge A; Barton, Nick; Rogerson, Mike; Brücher, Tim

    2013-01-01

    Human migration north through Africa is contentious. This paper uses a novel palaeohydrological and hydraulic modelling approach to test the hypothesis that under wetter climates c.100,000 years ago major river systems ran north across the Sahara to the Mediterranean, creating viable migration routes. We confirm that three of these now buried palaeo river systems could have been active at the key time of human migration across the Sahara. Unexpectedly, it is the most western of these three rivers, the Irharhar river, that represents the most likely route for human migration. The Irharhar river flows directly south to north, uniquely linking the mountain areas experiencing monsoon climates at these times to temperate Mediterranean environments where food and resources would have been abundant. The findings have major implications for our understanding of how humans migrated north through Africa, for the first time providing a quantitative perspective on the probabilities that these routes were viable for human habitation at these times.

  12. Were Rivers Flowing across the Sahara During the Last Interglacial? Implications for Human Migration through Africa

    PubMed Central

    Coulthard, Tom J.; Ramirez, Jorge A.; Barton, Nick; Rogerson, Mike; Brücher, Tim

    2013-01-01

    Human migration north through Africa is contentious. This paper uses a novel palaeohydrological and hydraulic modelling approach to test the hypothesis that under wetter climates c.100,000 years ago major river systems ran north across the Sahara to the Mediterranean, creating viable migration routes. We confirm that three of these now buried palaeo river systems could have been active at the key time of human migration across the Sahara. Unexpectedly, it is the most western of these three rivers, the Irharhar river, that represents the most likely route for human migration. The Irharhar river flows directly south to north, uniquely linking the mountain areas experiencing monsoon climates at these times to temperate Mediterranean environments where food and resources would have been abundant. The findings have major implications for our understanding of how humans migrated north through Africa, for the first time providing a quantitative perspective on the probabilities that these routes were viable for human habitation at these times. PMID:24040347

  13. Sediment supply as a driver of river evolution in the Amazon Basin

    NASA Astrophysics Data System (ADS)

    Ahmed, Joshua; Constantine, José Antonio; Dunne, Thomas; Legleiter, Carl; Lazarus, Eli D.

    2015-04-01

    The Amazon represents the only large river basin in the world where there is a sufficient range of sediment supplies and a lack of engineering controls to assess how sediment supply drives the evolution of meandering rivers. Despite recent analytical advances (Asahi et al., 2013; Pittaluga and Seminara, 2011), modern theory does not yet identify or explain the effects of externally imposed sediment supplies, a fundamental river characteristic, on meandering river evolution. These sediment supplies would be radically reduced by the construction of large dams proposed for the Amazon Basin (Finer and Jenkins, 2012). Here, we demonstrate that the sediment loads imposed by their respective drainage basins determine planform changes in lowland rivers across the Amazon. Our analysis, based on Landsat image sequences, indicates that rivers with high sediment loads draining the Andes and associated foreland basin experience annual migration rates that are on average four times faster than rivers with lower sediment loads draining the Central Amazon Trough and shields. Incidents of meander cutoff also occur more frequently along the rivers of the Andes and foreland basin, where the number of oxbows in the floodplains is more than twice that observed in the floodplains of the Central Amazon Trough and shields. Our results, which cannot be explained by differences in channel slope or hydrology, highlight the importance of sediment supply in modulating the ability of meandering alluvial rivers to reshape the floodplain environment through river migration. Asahi, K., Shimizu, Y., Nelson, J., Parker, G., 2013. Numerical simulation of river meandering with self-evolving banks. Journal of Geophysical Research: Earth Surface, 118(4), 2013JF002752. Finer, M., Jenkins, C.N., 2012. Proliferation of hydroelectric dams in the Andean Amazon and implications for Andes-Amazon connectivity. PLOS One, 7(4), e35126. Pittaluga, M.B., Seminara, G., 2011. Nonlinearity and unsteadiness in river

  14. The effects of floodplain soil heterogeneity on meander planform shape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Meander migration rates and patterns are a function of the forces exerted by the flowing water on the streambanks and the resistance to erosion of the bank soils. Past analytical studies of planform development have mostly focused on the complexity of the governing equations, i.e. hydrodynamics, and...

  15. Meander in valley crossing a deep-ocean fan.

    PubMed

    Shepard, F P

    1966-10-21

    Seaward of most submarine canyons there are large sediment fans comparable to the fans at the base of mountain ranges. Many of the submarine fans are cut by valleys called fan-valleys which usually connect with the mouths of submarine canyons. Loop-like bends or meanders characterize the channels of rivers in their lower flood plains, but have never been found in the shallow channels that cross the alluvial fans at the base of mountain canyons. Therefore, it was surprising to find that the channel in a very deep submarine fan-valley off Monterey Bay, California, has a tight meander.

  16. Highly Sinuous Terrestrial Mud Meanders as Martian Analogs

    NASA Astrophysics Data System (ADS)

    Matsubara, Y.; Howard, A. D.; Burr, D. M.; Williams, R. M.; Moore, J. M.

    2010-12-01

    Despite years of study questions remain about the factors determining stream patterns (e.g., braided versus meandering) and spatial patterns of floodplain deposition. Highly sinuous, unconfined meanders require small channel width to average depth ratios, which in turn require cohesive channel banks. On Earth, this cohesion is obtained most commonly by clay-rich sediment and vegetation cover. Roots can physically hold sediments intact and also retain moisture in the root zone, allowing minerals to weather to clay. Dense plant cover also encourages suspended (i.e., clay-rich) sediment deposition. However, the recent discovery of highly sinuous Martian meandering channels raises the question of how meandering can occur in the absence of vegetation. Quinn River located in the east branch of the Black Rock Desert, Nevada is a sinuous channel that flows through lacustrine sediments on the floor of paleolake Lahontan where vegetation cover is sparse. Lake and channel sediment samples, cross-sectional profiles, and various measurements of material strength (e.g., shear vane strength) were collected to characterize the Quinn River channel banks and bed. Similar data were also collected from two heavily vegetated, more classic meandering channels (the Humboldt River, also near Winnemucca, Nevada, and a tidal creek in Virginia) for comparison. Preliminary assessments of the samples indicate that Quinn river banks are more cohesive than those of the Humboldt River. They consist of finer sediments (mostly clay/silt to very fine sand) relative to the Humboldt River (ranging up to gravel size sediments in the point bar deposits). And they have a higher Atterberg Plasticity Index overall. Samples collected from the Quinn River bed and banks also effervesce in dilute hydrochloric acid. The concentration of chemical cements in bank samples and their role in providing cohesion are being evaluated. Highly sinuous channels on Mars show that meandering channels can occur without

  17. Relationship Between Vortex Meander and Ambient Turbulence

    NASA Technical Reports Server (NTRS)

    Rossow, Vernon J.; Hardy, Gordon H.; Meyn, Larry A.

    2006-01-01

    Efforts are currently underway to increase the capacity of airports by use of closely-spaced parallel runways. If such an objective is to be achieved safely and efficiently during both visual and instrument flight conditions, it will be necessary to develop more precise methods for the prediction of the motion and spread of the hazard posed by the lift-generated vortex-wakes of aircraft, and their uncertainties. The purpose of the present study is to relate the motion induced in vortex filaments by turbulence in the ambient flow field to the measured turbulence in the flow field. The problem came about when observations made in the two largest NASA wind tunnels indicated that extended exposure of vortex wakes to the turbulence in the wind tunnel air stream causes the centers of the vortices to meander about with time at a given downstream station where wake measurements are being made. Although such a behavior was expected, the turbulence level based on the maximum amplitude of meander was much less than the root-mean-squared value measured in the free-stream of the wind tunnel by use of hot-film anemometers. An analysis of the time-dependent motion of segments of vortex filaments as they interact with an eddy, indicates that the inertia of the filaments retards their motion enough in the early part of their travel to account for a large part of the difference in the two determinations of turbulence level. Migration of vortex filaments from one turbulent eddy to another (probably with a different orientation), is believed to account for the remainder of the difference. Methods that may possibly be developed for use in the measurement of the magnitude of the more intense eddies in turbulent flow fields and how they should be adjusted to predict vortex meander are then discussed.

  18. Late Pleistocene river migrations in response to thrust belt advance and sediment-flux steering - The Kura River (southern Caucasus)

    NASA Astrophysics Data System (ADS)

    von Suchodoletz, Hans; Gärtner, Andreas; Hoth, Silvan; Umlauft, Josefine; Sukhishvili, Lasha; Faust, Dominik

    2016-08-01

    One reaction of rivers toward allogenic triggers is the large-scale river channel migration in the form of avulsions or progressive lateral migrations (combing) that are widespread phenomena around the world during the late Quaternary. Because they potentially cause significant human and economic losses and significantly change geomorphic processes in the affected regions, a deeper knowledge about causes and rates is essential and furthermore helps to identify the dominant drivers of regional landscape evolution during different periods. One possible cause for river channel migrations is sediment-flux steering, i.e. the shift of rivers in sedimentary basins against a tectonically driven trend caused by transverse sediment discharge. During the last 30 years, sediment-flux steering has been investigated by field and experimental studies in extensional half-grabens with generally small-sized transverse catchments and/or volcaniclastic sedimentation. This study presents geomorphologic, geochronologic, and heavy mineral analyses together with complementary tectonomorphometric and earthquake data to investigate late Quaternary channel migrations of the Kura River in the southern foreland basin of the Greater Caucasus, a region where the late Quaternary landscape evolution is rather fragmentarily understood so far. Special emphasis of this study is given to the interplay between axial river flow and transverse sediment supply leading to sediment-flux steering. Large-scale migrations of the course of the Kura River during the late Quaternary reflect the interplay between tectonic processes leading to the southwestward advance of the Kura Fold-and-Thrust-Belt and climatically-triggered sediment-flux steering caused by aggradation phases of transverse rivers with comparatively large catchment areas in the Lesser Caucasus. During generally warmer periods such as the Holocene with fluvial incision and low sediment supply from the transverse rivers, the main Kura River could

  19. The Wavelet ToolKat: A set of tools for the analysis of series through wavelet transforms. Application to the channel curvature and the slope control of three free meandering rivers in the Amazon basin.

    NASA Astrophysics Data System (ADS)

    Vaudor, Lise; Piegay, Herve; Wawrzyniak, Vincent; Spitoni, Marie

    2016-04-01

    The form and functioning of a geomorphic system result from processes operating at various spatial and temporal scales. Longitudinal channel characteristics thus exhibit complex patterns which vary according to the scale of study, might be periodic or segmented, and are generally blurred by noise. Describing the intricate, multiscale structure of such signals, and identifying at which scales the patterns are dominant and over which sub-reach, could help determine at which scales they should be investigated, and provide insights into the main controlling factors. Wavelet transforms aim at describing data at multiple scales (either in time or space), and are now exploited in geophysics for the analysis of nonstationary series of data. They provide a consistent, non-arbitrary, and multiscale description of a signal's variations and help explore potential causalities. Nevertheless, their use in fluvial geomorphology, notably to study longitudinal patterns, is hindered by a lack of user-friendly tools to help understand, implement, and interpret them. We have developed a free application, The Wavelet ToolKat, designed to facilitate the use of wavelet transforms on temporal or spatial series. We illustrate its usefulness describing longitudinal channel curvature and slope of three freely meandering rivers in the Amazon basin (the Purus, Juruá and Madre de Dios rivers), using topographic data generated from NASA's Shuttle Radar Topography Mission (SRTM) in 2000. Three types of wavelet transforms are used, with different purposes. Continuous Wavelet Transforms are used to identify in a non-arbitrary way the dominant scales and locations at which channel curvature and slope vary. Cross-wavelet transforms, and wavelet coherence and phase are used to identify scales and locations exhibiting significant channel curvature and slope co-variations. Maximal Overlap Discrete Wavelet Transforms decompose data into their variations at a series of scales and are used to provide

  20. Survival of migrating salmon smolts in large rivers with and without dams.

    PubMed

    Welch, David W; Rechisky, Erin L; Melnychuk, Michael C; Porter, Aswea D; Walters, Carl J; Clements, Shaun; Clemens, Benjamin J; McKinley, R Scott; Schreck, Carl

    2008-10-28

    The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST) array. Survival measurements using acoustic tags were comparable to those obtained independently using the Passive Integrated Transponder (PIT) tag system, which is operational at Columbia and Snake River dams. Because the technology underlying the POST array works in both freshwater and the ocean, it is therefore possible to extend the measurement of survival to large rivers lacking dams, such as the Fraser, and to also extend the measurement of survival to the lower Columbia River and estuary, where there are no dams. Of particular note, survival during the downstream migration of at least some endangered Columbia and Snake River Chinook and steelhead stocks appears to be as high or higher than that of the same species migrating out of the Fraser River in Canada, which lacks dams. Equally surprising, smolt survival during migration through the hydrosystem, when scaled by either the time or distance migrated, is higher than in the lower Columbia River and estuary where dams are absent. Our results raise important questions regarding the factors that are preventing the recovery of salmon stocks in the Columbia and the future health of stocks in the Fraser River.

  1. Out of Africa: the importance of rivers as human migration corridors

    NASA Astrophysics Data System (ADS)

    Ramirez, J. A.; Coulthard, T. J.; Rogerson, M.; Barton, N.; Bruecher, T.

    2013-12-01

    The route and timing of Homo sapiens exiting Africa remains uncertain. Corridors leading out of Africa through the Sahara, the Nile Valley, and the Red Sea coast have been proposed as migration routes for anatomically modern humans 80,000-130,000 years ago. During this time climate conditions in the Sahara were wetter than present day, and monsoon rainfall fed rivers that flowed across the desert landscape. The location and timing of these rivers may have supported human migration northward from central Africa to the Mediterranean coast, and onwards to Europe or Asia. Here, we use palaeoclimate rainfall and a hydrological model to spatially simulate and quantitatively test the existence of three major rivers crossing the Sahara from south to north during the time of human migration. We provide evidence that, given realistic underlying climatology, the well-known Sahabi and Kufrah rivers very likely flowed across modern day Libya and reached the coast. More unexpectedly an additional river crossed the core of the Sahara through Algeria (Irharhar river) and flowed into the Chotts basin. The Irharhar river is unique, because it links locations in central Africa experiencing monsoon climates with temperate coastal Mediterranean environments where food and resources were likely abundant. From an ecological perspective, this little-known corridor may prove to be the most parsimonious migration route. Support for the Irharar as a viable migration corridor is provided by its geographic proximity to middle Stone Age archaeological artefacts found in North Africa. Our new, highly novel approach provides the first quantitative analysis of the likelihood that rivers occurred during the critical period of human migration out of Africa. Simulated probability of surface water in North Africa during the last interglacial and the location of tools and ornaments from the Middle Stone Age.

  2. Upstream migration of Pacific lampreys in the John Day River, Oregon: Behavior, timing, and habitat use

    USGS Publications Warehouse

    Robinson, T. Craig; Bayer, J.M.

    2005-01-01

    Adult Pacific lamprey migration and habitat preferences for over-winter holding and spawning, and larval rearing in tributaries to the Columbia River are not well understood. The John Day River is one such tributary where larval and adult stages of this species have been documented, and its free-flowing character provided the opportunity to study migration of Pacific lampreys unimpeded by passage constraints. Forty-two adult Pacific lampreys were captured in the John Day River near its mouth during their upstream migration. Pacific lampreys were surgically implanted with radio transmitters and released onsite, and tracked by fixed-site, aerial, and terrestrial telemetry methods for nearly one year. Adults moved upstream exclusively at night, with a mean rate of 11.1 ?? 6.3 km/day. They halted upstream migration by September, and held a single position for approximately six months in the lateral margins of riffles and glides, using boulders for cover. More than half of Pacific lampreys resumed migration in March before ending movement in early May. Pacific lampreys that resumed migration in spring completed a median of 87% of their upstream migration before over-winter holding. Upon completing migration. Pacific lampreys briefly held position before beginning downstream movement at the end of May. Though not directly observed, halting migration and movement downstream were likely the result of spawning and death. Gains in adult Pacific lamprey passage through the Columbia River hydrosystem and tributaries may be made by improvements that would expedite migration during spring and summer and increase the quantity and variety of cover and refuge opportunities. ?? 2005 by the Northwest Scientific Association. All rights reserved.

  3. Adult Pacific Lamprey Migration in the Lower Columbia River: 2007 Radiotelemetry and Half-duplex Pit Tag Studies

    DTIC Science & Technology

    2009-01-01

    ADULT PACIFIC LAMPREY MIGRATION IN THE LOWER COLUMBIA RIVER: 2007 RADIOTELEMETRY AND HALF-DUPLEX PIT TAG STUDIES A Report for Study Code ADS-P-00-8...TITLE AND SUBTITLE Adult Pacific Lamprey Migration in the Lower Columbia River: 2007 Radiotelemetry and Half-duplex Pit Tag Studies 5a. CONTRACT NUMBER...Monitoring Pacific lamprey (Lampetra tridentata) run size and migration behaviors in the Columbia River basin is difficult given their cryptic and photo

  4. Individual variation in migration speed of upriver-migrating sockeye salmon in the Fraser River in relation to their physiological and energetic status at marine approach.

    PubMed

    Hanson, Kyle C; Cooke, Steven J; Hinch, Scott G; Crossin, Glenn T; Patterson, David A; English, Karl K; Donaldson, Michael R; Shrimpton, J Mark; Van Der Kraak, Glen; Farrell, Anthony P

    2008-01-01

    Little research has examined individual variation in migration speeds of Pacific salmon (Oncorhynchus spp.) in natural river systems or attempted to link migratory behavior with physiological and energetic status on a large spatial scale in the wild. As a model, we used three stocks of summer-run sockeye salmon (Oncorhynchus nerka) from the Fraser River watershed, British Columbia, to test the hypothesis that individual variation in migration speed is determined by a combination of environmental factors (i.e., water temperature), intrinsic biological differences (sex and population), and physiological and energetic condition. Before the freshwater portion of the migration, sockeye salmon (Quesnel, Chilcotin, and Nechako stock complexes) were captured in Johnstone Strait ( approximately 215 km from river entry), gastrically implanted with radio transmitters, and sampled for blood, gill tissue, and energetic status before release. Analyses focused solely on individuals that successfully reached natal subwatersheds. Migration speeds were assessed by an extensive radiotelemetry array. Individuals from the stock complex that migrated the longest distance (Nechako) traveled at speeds slower than those of other stock complexes. Females traveled slower than males. An elevated energetic status of fish in the ocean was negatively correlated with migration speed in most river segments. During the transition from the ocean to the river, migration speed was negatively correlated with mean maximum water temperature; however, for the majority of river segments, it was positively correlated with migration speed. Physiological status measured in the ocean did not explain among-individual variability in river migration speeds. Collectively, these findings suggest that there could be extensive variation in migration behavior among individuals, sexes, and populations and that physiological condition in the ocean explained little of this variation relative to in-river environmental

  5. Self-Formed Meandering and Braided Channel Patterns in a Numerical Model

    NASA Astrophysics Data System (ADS)

    Schuurman, F.; Kleinhans, M. G.

    2010-12-01

    The initiation of bars in a river is caused by the interaction between flow and bed material as demonstrated by linear stability analyses, flume experiments and numerical modeling. Bar pattern determines where bank erosion takes place, which may lead to meandering in case of alternate bars combined with cohesive sediment or vegetation. Linear stability analyses provide a way to predict the initially dominant wavelength and bar mode. However, after initiation of bars, non-linear effects become dominant, rendering the analyses of limited use for real world prediction. Our objective is to understand the necessary and sufficient conditions for different river patterns. We combine flume experiments (Kleinhans et al., van Dijk et al., this conference) with field data (van den Berg et al., this conference) and linear stability analysis in comparison to numerical modeling. We used the quasi-3D-morphological model Delft3D to model the development of channel patterns, starting from a plane bed. The initial bed slope, bed particle size, upstream discharge, channel width and downstream water level were varied systematically across a large range of various river patterns from a large dataset of real rivers (van den Berg et al., this conference). Random noise was added to the initial bed (5 mm noise) and to the discharge (0.5% noise). The frequency of discharge-induced bar formation is several orders of magnitude smaller than the frequency of the discharge perturbation. The modeling shows that initially, relative small sized bars with a high mode develop in the entire reach. In case of an alternating bar pattern, the discharge-induced bars are relative low (order 0.2% of the waterdepth) and grow in downstream direction towards a height of 1.4%. The alternating bars continuously migrate in downstream direction (free bars), without the decrease in celerity predicted by linear stability analyses. In case of a braiding bar pattern (mode 7-8), the discharge-induced bars initially are

  6. Environmental correlates of upstream migration of yellow-phase American eels in the Potomac River drainage

    USGS Publications Warehouse

    Welsh, Stuart; Heather L. Liller,

    2013-01-01

    Assessing the relationships between upstream migration and environmental variables is important to understanding the ecology of yellow-phase American Eels Anguilla rostrata. During an American Eel migration study within the lower Shenandoah River (Potomac River drainage), we counted and measured American Eels at the Millville Dam eel ladder for three periods: 14 May–23 July 2004, 7–30 September 2004, and 1 June–31 July 2005. Using generalized estimating equations, we modeled each time series of daily American Eel counts by fitting time-varying environmental covariates of lunar illumination (LI), river discharge (RD), and water temperature (WT), including 1-d and 2-d lags of each covariate. Information-theoretic approaches were used for model selection and inference. A total of 4,847 American Eels (19–74 cm total length) used the ladder during the three periods, including 2,622 individuals during a 2-d span following a hurricane-induced peak in river discharge. Additive-effects models of RD + WT, a 2-d lag of LI + RD, and LI + RD were supported for the three periods, respectively. Parameter estimates were positive for river discharge for each time period, negative for lunar illumination for two periods and positive for water temperature during one period. Additive-effects models supported synergistic influences of environmental variables on the upstream migration of yellow-phase American Eels, although river discharge was consistently supported as an influential correlate of upstream migration.

  7. Three-dimensional flow structure and patterns of bed shear stress in an evolving compound meander bend

    USGS Publications Warehouse

    Engel, Frank; Rhoads, Bruce L.

    2016-01-01

    Compound meander bends with multiple lobes of maximum curvature are common in actively evolving lowland rivers. Interaction among spatial patterns of mean flow, turbulence, bed morphology, bank failures and channel migration in compound bends is poorly understood. In this paper, acoustic Doppler current profiler (ADCP) measurements of the three-dimensional (3D) flow velocities in a compound bend are examined to evaluate the influence of channel curvature and hydrologic variability on the structure of flow within the bend. Flow structure at various flow stages is related to changes in bed morphology over the study timeframe. Increases in local curvature within the upstream lobe of the bend reduce outer bank velocities at morphologically significant flows, creating a region that protects the bank from high momentum flow and high bed shear stresses. The dimensionless radius of curvature in the upstream lobe is one-third less than that of the downstream lobe, with average bank erosion rates less than half of the erosion rates for the downstream lobe. Higher bank erosion rates within the downstream lobe correspond to the shift in a core of high velocity and bed shear stresses toward the outer bank as flow moves through the two lobes. These erosion patterns provide a mechanism for continued migration of the downstream lobe in the near future. Bed material size distributions within the bend correspond to spatial patterns of bed shear stress magnitudes, indicating that bed material sorting within the bend is governed by bed shear stress. Results suggest that patterns of flow, sediment entrainment, and planform evolution in compound meander bends are more complex than in simple meander bends. Moreover, interactions among local influences on the flow, such as woody debris, local topographic steering, and locally high curvature, tend to cause compound bends to evolve toward increasing planform complexity over time rather than stable configurations.

  8. Quantifying Knick Point Migration Rates Related to the Messinian Crisis. The Case of the Nile River

    NASA Astrophysics Data System (ADS)

    Stüwe, Kurt; Pucher, Christoph; Robl, Jörg; Hergarten, Stefan

    2016-04-01

    The Messinian crisis is a temporally well-constrained period between 5.3 my and 5.9 my, when the strait of Gibraltar was tectonically closed and the Mediterranean Sea had consequently desiccated. This dramatic base level drop by about 1500 vertical meters had a profound influence on the geomorphic evolution of the major drainages surrounding the Mediterranean basin. In particular, it caused substantial knickpoints in the major rivers including the Rhone, the Ebro, the Po and the Nile. While the knickpoints of the Rhone and Ebro have been studied previously and the knickpoints created by the Po may lie today underneath the Po plains, the knickpoint and its migration along the Nile has not been studied and would have migrated along its current river channel. In this contribution we focus on numerical modelling of the knickpoint migration in the Nile and use our modelling results in comparison with the present day morphological analyses of the river to constrain absolute migration rates. We suspect that the first Nile cataract near Assuan, some 1000 km upstream of today's river mouth may be the relict of the Messinian salinity crisis making it to one of the fastest migrating knickpoints in the world.

  9. Seasonal migration and homing of channel catfish in the lower Wisconsin River, Wisconsin

    USGS Publications Warehouse

    Pellett, Thomas D.; Van Dyck, Gene J.; Adams, Jean V.

    1998-01-01

    A multiyear tag and recapture study was conducted to determine whether channel catfishIctalurus punctatus were migratory and if they had strong homing tendencies. Over 10,000 channel catfish were tagged from the lower Wisconsin River and adjacent waters of the upper Mississippi River during the 3-year sampling period. Data on movements were obtained from study recaptures and through tag returns and harvest information provided by sport anglers and commercial fishers. Channel catfish occupied relatively small home ranges during summer, migrated downstream to the upper Mississippi River in autumn, then migrated back up the Wisconsin River in spring to spawn and to occupy the same summer home sites they had used in previous summers. Fish size was a factor in the degree of fidelity to summer home sites, with larger fish showing greater fidelity.

  10. St. Louis River fish migrations: Gains and losses of ecosystem ...

    EPA Pesticide Factsheets

    The Twin Ports fishery has undergone change from a migratory fish-based fishery to a Lake Superior-based fishery, and is now returning to a diverse fishery that includes fish of both life histories. These changes reflect past disturbances to the Great Lakes ecosystem as well as recent water quality improvement and efforts to restore habitat in the St. Louis River. Migratory fishes are an important ecosystem service for the St. Louis River, and improvements to the ecosystem quality within the St. Louis River Area of Concern has benefited migratory fishes. The coastal wetlands within the lower river provide direct support to a variety of high-value, recreationally-important fish species, including walleye, northern pike, and bass. Moreover, these wetlands serve as nursery habitat for a broader suite of high-value, commercially-important species. Restoration has likely improved the value of these coastal wetlands because low-value rough species tend to be more prevalent in degraded coastal wetlands, whereas high-value commercial and game fishes are more prevalent in high-quality coastal wetlands. There have been losses in ecosystem services, as well. Owing to legacy contamination of mercury and PCBs, migratory fishes in the St. Louis River have sufficiently high contaminant burdens to warrant consumption advisories, and recent movement research demonstrates that there is a positive relationship between increased use of St. Louis River habitat (versus Lake Superior)

  11. Adult Pacific Lamprey Migration in the Lower Columbia River: 2011 Half-Duplex Pit Tag Studies

    DTIC Science & Technology

    2012-01-01

    Kasey Welch, Miro Zyndol, Robert Cordie , Brad Eby, and Mark Plummer. iv Table of Contents Executive Summary...reaches upstream from Bonneville Dam included one reservoir and one dam. Median migration rates ranged from 5-18 km●d-1 in reservoir- plus -dam reaches...River radiotelemetry studies, tributary 26 detection has occurred primarily at the Deschutes, Klickitat, and John Day rivers plus Fifteenmile

  12. Optical remote sensing of bedforms in a field-scale meandering channel

    NASA Astrophysics Data System (ADS)

    Palmsten, M. L.; Kozarek, J. L.; Calantoni, J.

    2012-12-01

    The morphology and migration rate of bedforms in a sandy meander vary as a result of differences in boundary shear stress around the meander bend. The objective of this work is to quantify bedform size and migration rate using synoptic observations of remotely sensed water depth around a meander bend. We conducted an experiment from 9-20 July 2012 at the Saint Anthony Falls Laboratory Outdoor StreamLab (OSL), University of Minnesota. The OSL consists of a bedload dominated, sandy (D50 = 0.7 mm) meandering channel approximately 40 m in length, 2.7 m in width, and 0.3 m in depth. Riffles were installed upstream and downstream of the meander bend. Discharge was fixed at 199 L/s throughout the experiment and sediment feed rate was 4.1 kg/min. Four color video cameras were mounted on a tower 5 m above the floodplain on the inner bank of the meander looking down into the stream. Two additional cameras, including one near infra-red camera were mounted on the outer bank of the meander. Video data were supplemented by 1 mm resolution measurements of velocity and sonar observations of bed elevation. The sonar and video data were used to create a transfer function between pixel intensity and water depth and pixel location was corrected for refraction, resulting ~0.01 m resolution depth measurements along the entire meander bend. Initially, the stream bed was flat. A pool formed immediately downstream of the riffle. A point bar and ripples developed during the first hour of the experiment. The morphology of bedforms changed with position around the meander bend from convex upstream to convex downstream. The sinuosity of bedforms also increased around the meander bend, reaching maximum near the bend apex. Bedform wavelength increased around the meander bend from 0.5 m upstream of the bend apex to > 1.5 m downstream of the bed apex. Bedform spacing increased as alternating bedforms increased in amplitude while neighboring bedforms decreased in amplitude until they disappeared

  13. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 2000 Annual Report.

    SciTech Connect

    Achord, Stephen

    2001-08-01

    This report details the 2000 results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends in the cumulative data collected for this project from Oregon and Idaho streams since 1989.

  14. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1999 Annual Report.

    SciTech Connect

    Achord, Stephen

    2001-06-01

    This report details the 1999 results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends in the cumulative data collected for this project from Oregon and Idaho streams since 1989.

  15. Monitoring the Migrations of Wild Snake River Spring and Summer Chinook Salmon Smolts, 1992 Annual Report.

    SciTech Connect

    Achord, Stephen; Marsh, Douglas M.; Kamikawa, Daniel J.

    1994-09-01

    We PIT tagged wild spring and summer chinook salmon parr in the Snake River Basin in 1991, and subsequently monitored these fish during their smolt migration through Lower Granite, Little Goose, and McNary Dams during spring and summer 1992. This report details our findings.

  16. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1996 Annual Report.

    SciTech Connect

    Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

    1997-07-01

    We PIT tagged wild spring/summer chinook salmon parr in the Snake River Basin in 1995 and subsequently monitored these fish during their smolt migration through Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams during spring and summer 1996.

  17. Meander cutoff and the controls on the production of oxbow lakes

    NASA Astrophysics Data System (ADS)

    Constantine, José Antonio; Dunne, Thomas

    2008-01-01

    Using satellite images archived by Google EarthTM, we measuredchannel and oxbow-lake characteristics of 30 large meanderingrivers to identify the controls on the production of oxbow lakesby meander cutoff. Cutoff produced lognormal distributions oflake lengths within the studied reaches, and the geometric meanlake length of each population correlated positively and exponentiallywith sinuosity, due to more highly sinuous reaches being comprisedof longer meanders and to cutoff removing longer segments ofmore sinuous channels. We successfully predicted the size-frequencydistributions of lakes stored within the flood-plains of fivefreely meandering reaches using only channel sinuosity and anassumption of the variance about the geometric mean lake length,a variable that did not significantly vary between the studiedreaches. While the river's sinuosity remains steady, the temporalrate of cutoff can be estimated using channel sinuosity, thefraction by which cutoff reduces channel length, and the rateat which the reach lengthens by meander growth.

  18. Interactions between hyporheic flow produced by stream meanders, bars, and dunes

    USGS Publications Warehouse

    Stonedahl, Susa H.; Harvey, Judson W.; Packman, Aaron I.

    2013-01-01

    Stream channel morphology from grain-scale roughness to large meanders drives hyporheic exchange flow. In practice, it is difficult to model hyporheic flow over the wide spectrum of topographic features typically found in rivers. As a result, many studies only characterize isolated exchange processes at a single spatial scale. In this work, we simulated hyporheic flows induced by a range of geomorphic features including meanders, bars and dunes in sand bed streams. Twenty cases were examined with 5 degrees of river meandering. Each meandering river model was run initially without any small topographic features. Models were run again after superimposing only bars and then only dunes, and then run a final time after including all scales of topographic features. This allowed us to investigate the relative importance and interactions between flows induced by different scales of topography. We found that dunes typically contributed more to hyporheic exchange than bars and meanders. Furthermore, our simulations show that the volume of water exchanged and the distributions of hyporheic residence times resulting from various scales of topographic features are close to, but not linearly additive. These findings can potentially be used to develop scaling laws for hyporheic flow that can be widely applied in streams and rivers.

  19. Migration of precocious male hatchery chinook salmon in the Umatilla River, Oregon

    USGS Publications Warehouse

    Zimmerman, C.E.; Stonecypher, R.W.; Hayes, M.C.

    2003-01-01

    Between 1993 and 2000, precocious yearling males of hatchery-produced fall and spring chinook salmon Oncorhynchus tshawytscha composed 3.6-82.1% of chinook salmon runs to the Umatilla River, Oregon. These yearling males are smaller than typical jack salmon, which spend a full winter in the ocean, and are commonly referred to as "mini jacks." Minijack fall chinook salmon are characterized by enlarged testes and an increased gonadosomatic index. Our goal was to determine if minijacks migrated to saltwater between the time they are released from the hatchery and the time they return to the Umatilla River, a period of 4-6 months. During 1999-2000, we collected otoliths from an adult male fall chinook salmon, 12 spring chinook salmon minijacks, and 10 fall chinook salmon minijacks. We measured strontium:calcium (Sr:Ca) ratios from the age-1 annulus to the edge of the otolith to determine whether these fish had migrated to the ocean. The Sr:Ca ratios increased from low values near the age-1 annulus, similar to ratios expected from freshwaters, to higher values near the edge of the otolith. The Sr:Ca ratios increased to levels similar to ratios expected in saltwater, indicating that these fish had migrated to saltwater before returning to the Umatilla River. Analysis of published water chemistry data from the Columbia and Snake rivers and rearing experiments in the main-stem Columbia River confirmed that high Sr:Ca ratios measured in otoliths were not the result of high strontium levels encountered in the freshwater environment. Previously assumed to remain within freshwater and near the point of release, our results suggest these minijack salmon migrated at least 800 km and past three hydroelectric dams to reach saltwater and return to the Umatilla River.

  20. Spawning migration of telemetered striped bass in the Roanoke River, North Carolina

    USGS Publications Warehouse

    Carmichael, J.T.; Haeseker, S.L.; Hightower, J.E.

    1998-01-01

    The spring spawning migration is a key period for effective management of anadromous populations of striped bass Morone saxatilis. Information on migratory behavior is needed in order to develop appropriate harvest regulations and to conduct effective surveys while fish are on the spawning grounds. We used ultrasonic telemetry to estimate the timing and duration of the upriver spawning migration for the Roanoke River, North Carolina, population and to evaluate whether a short-term fluctuation in temperature or flow would alter the distribution of telemetered fish on the spawning grounds. Seventy-eight fish implanted with transmitters were released during 1993 and 1994. Twenty-nine telemetered fish migrated upriver in 1994, and 14 telemetered fish entered the river in 1995. Migration of telemetered fish began in mid- to late April when water temperatures in the lower river reached 17-18??C. Males began their spawning migration significantly earlier than females in 1994; the difference was not significant in 1995. The 165-km upriver migration took about a week, as did the downriver migration after the spawning season. In 1994 and 1995 respectively, males remained on the spawning grounds for averages of 22 and 21 d, females for 8 and 11 d. Because of shorter residency times only about half the telemetered females were on the spawning grounds at any one time during the peak of the spawning season. Striped bass remained on the spawning grounds during a short-term temperature decrease of about 4??C (over 5 d) and an increase in flow from about 190 to 390 m3/s (over 1 d).

  1. Spawning migration movements of Lost River and shortnose suckers in the Williamson and Sprague Rivers, Oregon, following the removal of Chiloquin Dam-2009 Annual Report

    USGS Publications Warehouse

    Ellsworth, Craig M.; VanderKooi, Scott P.

    2011-01-01

    The Chiloquin Dam was located at river kilometer (rkm) 1.3 on the Sprague River near the town of Chiloquin, Oregon. The dam was identified as a barrier that potentially inhibited or prevented the upstream spawning migrations and other movements of endangered Lost River suckers (Deltistes luxatus), shortnose suckers (Chasmistes brevirostris), and other fish in the Sprague River. Our research objectives in 2009 were to evaluate adult catostomid spawning migration patterns using radio telemetry to identify and describe shifts in spawning area distribution and migration behavior following the removal of Chiloquin Dam in 2008. We attached external radio transmitters to 58 Lost River suckers and 59 shortnose suckers captured at the Williamson River fish weir. A total of 17 radio-tagged Lost River suckers and one radio-tagged shortnose sucker were detected approaching the site of the former Chiloquin Dam but only two radio-tagged fish (one male Lost River sucker and one female Lost River sucker) were detected crossing upstream of the dam site. A lower proportion of radio-tagged shortnose suckers were detected migrating into the Sprague River when compared with previous years. Detections on remote passive integrated transponder (PIT) tag arrays located in the Sprague River show that although the proportion of fish coming into the Sprague River is small when compared to the number of fish crossing the Williamson River fish weir, the number of fish migrating upstream of the Chiloquin Dam site increased exponentially in the first year since its removal. These data will be used in conjunction with larval production and adult spawning distribution data to evaluate the effectiveness of dam removal in order to provide increased access to underutilized spawning habitat located further upstream in the Sprague River and to reduce the crowding of spawning fish below the dam site.

  2. Evaluating spawning migration patterns and predicting spawning success of shovelnose sturgeon in the Lower Missouri River

    USGS Publications Warehouse

    Wildhaber, M.L.; Holan, S.H.; Davis, G.M.; Gladish, D.W.; DeLonay, A.J.; Papoulias, D.M.; Sommerhauser, D.K.

    2011-01-01

    Approaches using telemetry, precise reproductive assessments, and surgically implanted data storage tags (DSTs) were used in combination with novel applications of analytical techniques for fish movement studies to describe patterns in migratory behavior and predict spawning success of gravid shovelnose sturgeon. From 2004 to 2007, over 300 gravid female shovelnose sturgeon (Scaphirhynchus platorynchus) from the Lower Missouri River, that were expected to spawn in the year they were collected, were surgically implanted with transmitters and archival DSTs. Functional cluster modeling of telemetry data from the spawning season suggested two common migration patterns of gravid female shovelnose sturgeon. Fish implanted from 958 to 1181 river kilometer (rkm) from the mouth of the Missouri River (or northern portion of the Lower Missouri River within 354 rkm of the lowest Missouri River dam at rkm 1305) had one migration pattern. Of fish implanted from 209 to 402 rkm from the mouth of the Missouri River (or southern portion of the Lower Missouri River), half demonstrated a movement pattern similar to the northern fish while the other half demonstrated a migration pattern that covered more of the river. There was no apparent difference in migration patterns between successful and unsuccessful spawners. Multiple hypotheses exist to explain differences in migratory patterns among fish from different river reaches. Additional work is required to determine if observed differences are due to multiple adapted strategies, environmental alteration, and/or initial tagging date. Hierarchical Bayesian modeling of DST data indicated that variation in depth usage patterns was consistently different between successful and unsuccessful spawners, as indicated by differences in likelihood of switching between high and low variability states. Analyses of DST data, and data collected at capture, were sufficient to predict 8 of 10 non-spawners/incomplete spawners and all 30 spawners in the

  3. Evaluating spawning migration patterns and predicting spawning success of shovelnose sturgeon in the Lower Missouri River

    USGS Publications Warehouse

    Wildhaber, M.L.; Holan, S.H.; Davis, G.M.; Gladish, D.W.; DeLonay, A.J.; Papoulias, D.M.; Sommerhauser, D.K.

    2011-01-01

    Approaches using telemetry, precise reproductive assessments, and surgically implanted data storage tags (DSTs) were used in combination with novel applications of analytical techniques for fish movement studies to describe patterns in migratory behavior and predict spawning success of gravid shovelnose sturgeon. From 2004 to 2007, over 300 gravid female shovelnose sturgeon (Scaphirhynchus platorynchus) from the Lower Missouri River, that were expected to spawn in the year they were collected, were surgically implanted with transmitters and archival DSTs. Functional cluster modeling of telemetry data from the spawning season suggested two common migration patterns of gravid female shovelnose sturgeon. Fish implanted from 958 to 1181 river kilometer (rkm) from the mouth of the Missouri River (or northern portion of the Lower Missouri River within 354rkm of the lowest Missouri River dam at rkm 1305) had one migration pattern. Of fish implanted from 209 to 402rkm from the mouth of the Missouri River (or southern portion of the Lower Missouri River), half demonstrated a movement pattern similar to the northern fish while the other half demonstrated a migration pattern that covered more of the river. There was no apparent difference in migration patterns between successful and unsuccessful spawners. Multiple hypotheses exist to explain differences in migratory patterns among fish from different river reaches. Additional work is required to determine if observed differences are due to multiple adapted strategies, environmental alteration, and/or initial tagging date. Hierarchical Bayesian modeling of DST data indicated that variation in depth usage patterns was consistently different between successful and unsuccessful spawners, as indicated by differences in likelihood of switching between high and low variability states. Analyses of DST data, and data collected at capture, were sufficient to predict 8 of 10 non-spawners/incomplete spawners and all 30 spawners in the

  4. Mississippi River and sea surface height effects on oil slick migration.

    PubMed

    Falcini, Frederico; Jerolmack, Douglas J; Nardelli, Bruno Buongiorno

    2012-01-01

    Millions of barrels of oil escaped into the Gulf of Mexico (GoM) after the 20 April, 2010 explosion of Deepwater Horizon (DH). Ocean circulation models were used to forecast oil slick migration in the GoM, however such models do not explicitly treat the effects of secondary eddy-slopes or Mississippi River (MR) hydrodynamics. Here we report oil front migration that appears to be driven by sea surface level (SSL) slopes, and identify a previously unreported effect of the MR plume: under conditions of relatively high river discharge and weak winds, a freshwater mound can form around the MR Delta. We performed temporal oil slick position and altimeter analysis, employing both interpolated altimetry data and along-track measurements for coastal applications. The observed freshwater mound appears to have pushed the DH oil slick seaward from the Delta coastline. We provide a physical mechanism for this novel effect of the MR, using a two-layer pressure-driven flow model. Results show how SSL variations can drive a cross-slope migration of surface oil slicks that may reach velocities of order km/day, and confirm a lag time of order 5-10 days between mound formation and slick migration, as observed form the satellite analysis. Incorporating these effects into more complex ocean models will improve forecasts of slick migration for future spills. More generally, large SSL variations at the MR mouth may also affect the dispersal of freshwater, nutrients and sediment associated with the MR plume.

  5. Mississippi River and Sea Surface Height Effects on Oil Slick Migration

    PubMed Central

    Falcini, Frederico; Jerolmack, Douglas J.; Buongiorno Nardelli, Bruno

    2012-01-01

    Millions of barrels of oil escaped into the Gulf of Mexico (GoM) after the 20 April, 2010 explosion of Deepwater Horizon (DH). Ocean circulation models were used to forecast oil slick migration in the GoM, however such models do not explicitly treat the effects of secondary eddy-slopes or Mississippi River (MR) hydrodynamics. Here we report oil front migration that appears to be driven by sea surface level (SSL) slopes, and identify a previously unreported effect of the MR plume: under conditions of relatively high river discharge and weak winds, a freshwater mound can form around the MR Delta. We performed temporal oil slick position and altimeter analysis, employing both interpolated altimetry data and along-track measurements for coastal applications. The observed freshwater mound appears to have pushed the DH oil slick seaward from the Delta coastline. We provide a physical mechanism for this novel effect of the MR, using a two-layer pressure-driven flow model. Results show how SSL variations can drive a cross-slope migration of surface oil slicks that may reach velocities of order km/day, and confirm a lag time of order 5–10 days between mound formation and slick migration, as observed form the satellite analysis. Incorporating these effects into more complex ocean models will improve forecasts of slick migration for future spills. More generally, large SSL variations at the MR mouth may also affect the dispersal of freshwater, nutrients and sediment associated with the MR plume. PMID:22558317

  6. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1994-1995 Progress (Annual) Report.

    SciTech Connect

    Achord, Stephen

    1996-09-01

    We PIT tagged wild spring/summer chinook-salmon parr in the Snake River Basin in 1994 and subsequently monitored these fish during their smolt migration through Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Darns during spring, summer, and fall 1995. This report details our findings. The goals of this study are to (1) characterize the migration timing of different wild stocks of Snake River spring/summer chinook salmon smolts at dams on the Snake and Columbia Rivers, (2) determine if consistent patterns are apparent, and (3) determine what environmental factors influence migration timing.

  7. Testing the role of meander cutoff in promoting gene flow across a riverine barrier in ground skinks (Scincella lateralis).

    PubMed

    Jackson, Nathan D; Austin, Christopher C

    2013-01-01

    Despite considerable attention, the long-term impact of rivers on species diversification remains uncertain. Meander loop cutoff (MLC) is one river phenomenon that may compromise a river's diversifying effects by passively transferring organisms from one side of the river to the other. However, the ability of MLC to promote gene flow across rivers has not been demonstrated empirically. Here, we test several predictions of MLC-mediated gene flow in populations of North American ground skinks (Scincella lateralis) separated by a well-established riverine barrier, the Mississippi River: 1) individuals collected from within meander cutoffs should be more closely related to individuals across the river than on the same side, 2) individuals within meander cutoffs should contain more immigrants than individuals away from meander cutoffs, 3) immigration rates estimated across the river should be highest in the direction of the cutoff event, and 4) the distribution of alleles native to one side of the river should be better predicted by the historical rather than current path of the river. To test these predictions we sampled 13 microsatellite loci and mitochondrial DNA from ground skinks collected near three ancient meander loops. These predictions were generally supported by genetic data, although support was stronger for mtDNA than for microsatellite data. Partial support for genetic divergence of samples within ancient meander loops also provides evidence for the MLC hypothesis. Although a role for MLC-mediated gene flow was supported here for ground skinks, the transient nature of river channels and morphologies may limit the long-term importance of MLC in stemming population divergence across major rivers.

  8. Gulf sturgeon spawning migration and habitat in the Choctawhatchee River system, Alabama-Florida

    USGS Publications Warehouse

    Fox, D.A.; Hightower, J.E.; Parauka, F.M.

    2000-01-01

    Information about spawning migration and spawning habitat is essential to maintain and ultimately restore populations of endangered and threatened species of anadromous fish. We used ultrasonic and radiotelemetry to monitor the movements of 35 adult Gulf sturgeon Acipenser oxyrinchus desotoi (a subspecies of the Atlantic sturgeon A. oxyrinchus) as they moved between Choctawhatchee Bay and the Choctawhatchee River system during the spring of 1996 and 1997. Histological analysis of gonadal biopsies was used to determine the sex and reproductive status of individuals. Telemetry results and egg sampling were used to identify Gulf sturgeon spawning sites and to examine the roles that sex and reproductive status play in migratory behavior. Fertilized Gulf sturgeon eggs were collected in six locations in both the upper Choctawhatchee and Pea rivers. Hard bottom substrate, steep banks, and relatively high flows characterized collection sites. Ripe Gulf sturgeon occupied these spawning areas from late March through early May, which included the interval when Gulf sturgeon eggs were collected. For both sexes, ripe fish entered the Choctawhatchee River significantly earlier and at a lower water temperature and migrated further upstream than did nonripe fish. Males entered the Choctawhatchee River at a lower water temperature than females. Results from histology and telemetry support the hypothesis that male Gulf sturgeon may spawn annually, whereas females require more than 1 year between spawning events. Upper river hard bottom areas appear important for the successful spawning of Gulf sturgeon, and care should be taken to protect against habitat loss or degradation of known spawning habitat.

  9. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1994 Annual Report.

    SciTech Connect

    Achord, Stephen; Matthews, Gene M.; Kamikawa, Daniel J.

    1995-09-01

    The goals of this study are to (1) characterize the outmigration timing of different wild stocks of spring/summer chinook salmon smolts at dams on the Snake and Columbia Rivers, (2) determine if consistent patterns are apparent, and (3) determine what environmental factors influence outmigration timing. The authors PIT tagged wild spring/summer chinook salmon parr in the Snake River Basin in 1993, and subsequently monitored these fish during their smolt migration through Lower Granite, Little Goose, Lower Monumental, and McNary Dams during spring, summer, and fall 1994. This report details their findings.

  10. Depositional processes of a meandering channel on Mississippi fan

    SciTech Connect

    Kastens, K.A.; Shor, A.N.

    1985-02-01

    A continuous, meandering, leveed channel traverses the Mississippi fan from the continental slope to the abyssal plain. Using water-gun seismic reflection profiling, 3.5- and 4.5-kHz profiling, and SeaMARC I side-scan sonar, the authors surveyed a 30-km (16-nmi) long channel segment midway between the slope break and channel terminus, where the channel bends through a tight meander with a 2.8-km (1.5-nmi) radius of curvature. At the entrance to each meander bend, the outer levee is unusually low, similar to the crevasses observed in rivers. The levees are constructed of an acoustically opaque unit and draped with an acoustically laminated unit; these are interpreted as coarser and finer grained overbank deposits, respectively. A series of high-amplitude seismic reflectors underlying the channel axis are interpreted as coarse sediments deposited from the base of turbidity currents. When last active, the channel was more than 100 m (300 ft) deep, but it has been filled to the brim by acoustically transparent units, leaving a levee crest/thalweg relief of as little as 5 m (16 ft). These channel-filling units are interpreted as debris flows. The upper surface of the debris flows is sculpted by flowline-parallel, side-scan lineations where the flow was unimpeded and by arcuate ridges transverse to the flow where bathymetric obstacles constrained the flow. 10 figures.

  11. The application of environmental numerical simulation in pollutants migration into river basin

    NASA Astrophysics Data System (ADS)

    Liang, Z. R.; Qin, Y. J.; Zhou, J. G.; Nan, H. Y.

    2017-01-01

    For the sustainable development of the social economy, it is very important that the water environment quality is analyzed, evaluated and predicted rationally, so that it could be planned, harnessed and managed effectively. To analyze and predict the water environment, the hydrodynamics behaviors and water pollution situations of the water body must be analyzed first based on hydrodynamics and water quality models. The objective of this work is to introduce how to establish river water dynamics and water quality model through the environment in the basin pollutant migration transformation rule, to simulate the rules and dynamics of river water pollution situation, to introduce the water quality model with geographic information system (GIS), and to apply the combination of environment numerical simulation to basin pollutant migration problem.

  12. Testing the Role of Meander Cutoff in Promoting Gene Flow across a Riverine Barrier in Ground Skinks (Scincella lateralis)

    PubMed Central

    Jackson, Nathan D.; Austin, Christopher C.

    2013-01-01

    Despite considerable attention, the long-term impact of rivers on species diversification remains uncertain. Meander loop cutoff (MLC) is one river phenomenon that may compromise a river’s diversifying effects by passively transferring organisms from one side of the river to the other. However, the ability of MLC to promote gene flow across rivers has not been demonstrated empirically. Here, we test several predictions of MLC-mediated gene flow in populations of North American ground skinks (Scincella lateralis) separated by a well-established riverine barrier, the Mississippi River: 1) individuals collected from within meander cutoffs should be more closely related to individuals across the river than on the same side, 2) individuals within meander cutoffs should contain more immigrants than individuals away from meander cutoffs, 3) immigration rates estimated across the river should be highest in the direction of the cutoff event, and 4) the distribution of alleles native to one side of the river should be better predicted by the historical rather than current path of the river. To test these predictions we sampled 13 microsatellite loci and mitochondrial DNA from ground skinks collected near three ancient meander loops. These predictions were generally supported by genetic data, although support was stronger for mtDNA than for microsatellite data. Partial support for genetic divergence of samples within ancient meander loops also provides evidence for the MLC hypothesis. Although a role for MLC-mediated gene flow was supported here for ground skinks, the transient nature of river channels and morphologies may limit the long-term importance of MLC in stemming population divergence across major rivers. PMID:23658778

  13. Ionoregulatory changes in different populations of maturing sockeye salmon Oncorhynchus nerka during ocean and river migration.

    PubMed

    Shrimpton, J M; Patterson, D A; Richards, J G; Cooke, S J; Schulte, P M; Hinch, S G; Farrell, A P

    2005-11-01

    We present the first data on changes in ionoregulatory physiology of maturing, migratory adult sockeye salmon Oncorhynchus nerka. Fraser River sockeye were intercepted in the ocean as far away as the Queen Charlotte Islands (approximately 850 km from the Fraser River) and during freshwater migration to the spawning grounds; for some populations this was a distance of over 700 km. Sockeye migrating in seawater toward the mouth of the Fraser River and upriver to spawning grounds showed a decline in gill Na+,K+-ATPase activity. As a result, gill Na+,K+-ATPase activity of fish arriving at the spawning grounds was significantly lower than values obtained from fish captured before entry into freshwater. Plasma osmolality and chloride levels also showed significant decreases from seawater values during the freshwater migration to spawning areas. Movement from seawater to freshwater increased mRNA expression of a freshwater-specific Na+,K+-ATPase isoform (alpha1a) while having no effect on the seawater-specific isoform (alpha1b). In addition, gill Na+,K+-ATPase activity generally increased in active spawners compared with unspawned fish on the spawning grounds and this was associated with a marked increase in Na+,K+-ATPase alpha1b mRNA. Increases in gill Na+,K+-ATPase activities observed in spawners suggests that the fish may be attempting to compensate for the osmotic perturbation associated with the decline in plasma chloride concentration and osmolality.

  14. Measurements of American rivers clarify influences on sinuosity

    NASA Astrophysics Data System (ADS)

    Kiel, B.

    2013-12-01

    We used the National Hydrography Dataset (NHD) to measure river widths and sinuosities nationally. Sinuosities were measured over reaches scaled by river width; sinuosity values typically increase with increasing reach length. By using short reaches of ~1 meander arc length, we aim to isolate sinuosity of channels meandering within floodplains. Spatial averaging of sinuosity over the eastern half of the U.S.--where measurements are dense--produces an intuitive map that we deem more useful than individual measurements. Sinuosity exhibits the following correlations: drainage density r = -0.34; soil sand content r = 0.54; land slope r = -0.37. We submit that lateral erosion of bend outer banks in sinuous rivers is driven by a self-reinforcing mass balance cycle wherein sand eroded from outer banks sustains point bar lateral accretion, which in turn sustains outer bend lateral erosion and forces passive lateral flow migration away from the advancing point bar.

  15. [Downstream migration, behavior, and distribution of fish fry in the lower reaches of the Ozernaya River (southwestern Kamchatka)].

    PubMed

    Pavlov, D S; Kirillova, E A; Kirillov, P I; Nezdoliĭ, V K

    2015-01-01

    Fry of five species of salmonids are found in the lower reaches of the Ozernaya River. The most abundant are chum salmon and pink salmon which compose the bulk of fry which migrate downstream from the river to the sea. The dates and duration of migration of particular species differed according to the specific traits of their biology. Pink salmon is characterized by a simple migration strategy: it migrated downstream in a short time after emergence from theground. Chum salmon has two strategies of downstream migration: some fry start migration soon after emergence, and others remained in the river for several weeks. Downstream migration of pink salmon occurred mainly at night in contrast to that of chum salmon, over 24 h, the part of daytime increased with growth, of the fish. Migration of pink salmon was passive. Passive migration of chum salmon changed into active-passive with growth of the fish. The ratio of fish in the inshore zone and in the current was different in the course of 24 h. The number of fish in the inshore zone decreased in the period of intensive downstream migration.

  16. Numerical modeling of dune progression in a high amplitude meandering channel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory experiments carried out by Abad and Garcia (2009) in a high-amplitude Kinoshita meandering channel show bed morphodynamics to comprise steady (local scour and deposition) and unsteady (migrating bedforms) components. The experiments are replicated with a numerical model. The sediment tran...

  17. Migration and habitats of diadromous Danube River sturgeons in Romania: 1998-2000

    USGS Publications Warehouse

    Kynard, B.; Suciu, R.; Horgan, M.

    2002-01-01

    Upstream migrant adults of stellate sturgeon, Acipenser stellatus (10 in 1998, 43 in 1999) and Russian sturgeon, A. gueldenstaedtii (three in 1999) were captured at river km (rkm) 58-137, mostly in the spring, and tagged with acoustic tags offering a reward for return. The overharvest was revealed by tag returns (38% in 1998, 28% in 1999) and by harvest within 26 days (and before reaching spawning grounds) of the six stellate sturgeon tracked upstream. A drop-back of > 50% of the tagged sturgeon, some to the Black Sea, shows a high sensitivity to interruption of migration and capture/handling/holding. Harvesting and dropback prevented tracking of sturgeon to spawning sites. Gillnetting and tracking of stellate sturgeon showed that the autumn migration ended in early October (river temperature 16??C) and identified a likely wintering area at river km (rkm) 75-76 (St George Branch). Thus, fishery harvesting after early October captures wintering fish, not migrants. Rare shoreline cliffs in the lower river likely create the only rocky habitat for sturgeon spawning. A survey for potential spawning habitats found five sites with rocky substrate and moderate water velocity, all ???rkm 258. Drift netting caught early life-stages of 17 fish species and one sturgeon, a beluga, Huso huso, larva likely spawned at ???rkm 258. All diadromous Danube sturgeons likely spawn at ???rkm 258.

  18. Synthesis of juvenile lamprey migration and passage research and monitoring at Columbia and Snake River Dams

    USGS Publications Warehouse

    Mesa, Matthew G.; Weiland, Lisa K.; Christiansen, Helena E.

    2016-01-01

    We compiled and summarized previous sources of data and research results related to the presence, numbers, and migration timing characteristics of juvenile (eyed macropthalmia) and larval (ammocoetes) Pacific lamprey Entosphenus tridentatus, in the Columbia River basin (CRB). Included were data from various screw trap collections, data from historic fyke net studies, catch records of lampreys at JBS facilities, turbine cooling water strainer collections, and information on the occurrence of lampreys in the diets of avian and piscine predators. We identified key data gaps and uncertainties that should be addressed in a juvenile lamprey passage research program. The goal of this work was to summarize information from disparate sources so that managers can use it to prioritize and guide future research and monitoring efforts related to the downstream migration of juvenile Pacific lamprey within the CRB. A common finding in all datasets was the high level of variation observed for CRB lamprey in numbers present, timing and spatial distribution. This will make developing monitoring programs to accurately characterize lamprey migrations and passage more challenging. Primary data gaps centered around our uncertainty on the numbers of juvenile and larval present in the system which affects the ability to assign risk to passage conditions and prioritize management actions. Recommendations include developing standardized monitoring methods, such as at juvenile bypass systems (JBS’s), to better document numbers and timing of lamprey migrations at dams, and use biotelemetry tracking techniques to estimate survival potentials for different migration histories.

  19. Streambed and water profile response to in-channel restoration structures in a laboratory meandering stream

    NASA Astrophysics Data System (ADS)

    Han, Bangshuai; Chu, Hong-Hanh; Endreny, Theodore A.

    2015-11-01

    In-channel structures are often installed in alluvial rivers during restoration to steer currents, but they also modify the streambed morphology and water surface profile, and alter hydraulic gradients driving ecologically important hyporheic exchange. Although river features before and after restoration need to be compared, few studies have collected detailed observations to facilitate this comparison. We created a laboratory mobile-bed alluvial meandering river and collected detailed measurements in the highly sinuous meander before and after installation of in-channel structures, which included one cross vane and six J-hooks situated along 1 bar unit. Measurements of streambed and water surface elevation with submillimeter vertical accuracy and horizontal resolution were obtained using close-range photogrammetry. Compared to the smooth gradually varied water surface profile for control runs without structures, the structures created rapidly varied flow with subcritical to supercritical flow transitions, as well as backwater and forced-morphology pools, which increased volumetric storage by 74% in the entire stream reach. The J-hooks, located along the outer bank of the meander bend and downstream of the cross vane, created stepwise patterns in the streambed and water surface longitudinal profiles. The pooling of water behind the cross vane increased the hydraulic gradient across the meander neck by 1% and increased local groundwater gradients by 4%, with smaller increases across other transects through the intrameander zone. Scour pools developed downstream of the cross vane and around the J-hooks situated near the meander apex. In-channel structures significantly changed meander bend hydraulic gradients, and the detailed streambed and water surface 3-D maps provide valuable data for computational modeling of changes to hyporheic exchange.

  20. Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration

    SciTech Connect

    Cook, Chris B.; Dibrani, Berhon; Richmond, Marshall C.; Bleich, Matthew D.; Titzler, P. Scott; Fu, Tao

    2006-01-30

    This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10°C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir’s epilimnion at the Clearwater/Snake River confluence is of key biological importance to juvenile fall Chinook salmon. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four lower Snake reservoirs are also heavily influenced by wind forcing at the water’s surface, and during periods of low river discharge, often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The depth of this upper warm layer and its direction of travel may also be of key

  1. Electronic tags and genetics explore variation in migrating steelhead kelts (oncorhynchus mykiss), Ninilchik river, Alaska

    USGS Publications Warehouse

    Nielsen, J.L.; Turner, S.M.; Zimmerman, C.E.

    2011-01-01

    Acoustic and archival tags examined freshwater and marine migrations of postspawn steelhead kelts (Oncorhynchus mykiss) in the Ninilchik River, Alaska, USA. Postspawn steelhead were captured at a weir in 2002-2005. Scale analysis indicated multiple migratory life histories and spawning behaviors. Acoustic tags were implanted in 99 kelts (2002-2003), and an array of acoustic receivers calculated the average speed of outmigration, timing of saltwater entry, and duration of residency in the vicinity of the river mouth. Ocean migration data were recovered from two archival tags implanted in kelts in 2004 (one male and one female). Archival tags documented seasonal differences in maximum depth and behavior with both fish spending 97% of time at sea <6 m depth (day and night). All study fish were double tagged with passive integrated transponder (PIT) tags implanted in the body cavity. Less than 4% of PIT tags were retained in postspawn steelhead. Molecular genetics demonstrated no significant differences in genetic population structure across years or among spawning life history types, suggesting a genetically panmictic population with highly diverse life history characteristics in the Ninilchik River.

  2. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1998 Annual Report.

    SciTech Connect

    Achord, Stephen; Hockersmith, Eric E.; Axel, Gordon A.

    2000-12-01

    This reports details the 1998 study results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends observed in the cumulative data resulting from this project; data has been collected from Oregon and Idaho streams since 1989. The project was initiated after 3 years of detection data from PIT-tags (passive-integrated-transponder tags) had shown distinct differences in migration patterns between wild and hatchery fish. Data showing these patterns had originated from tagging and interrogation operations begun in 1988 to evaluate a smolt transportation program conducted by the National Marine Fisheries Service (NMFS) for the US Army Corps of Engineers. In 1991, the Bonneville Power Administration began a cooperative effort with NMFS to expand tagging and interrogation of wild fish for this project. Project goals were to characterize the outmigration timing of these fish, to determine whether consistent migration patterns would emerge, and to investigate the influence of environmental factors on the timing and distribution of these migrations. In 1992, the Oregon Department of Fish and Wildlife (ODFW) began an independent program of PIT tagging wild chinook salmon parr in the Grande Ronde and Imnaha River Basins in northeast Oregon. Since then, ODFW has reported all tagging, detection, and timing information on fish from these streams. However, with ODFW concurrence, NMFS will continue to report arrival timing of these fish at Lower Granite Dam. We continued to tag fish from Idaho in all years subsequent to 1992. Principal results from our tagging and interrogation efforts during 1997-1998 are given.

  3. Migration and spawning of radio-tagged zulega Prochilodus argenteus in a dammed Brazilian river

    USGS Publications Warehouse

    Godinho, Alexandre L.; Kynard, B.

    2006-01-01

    It is difficult for agencies to evaluate the impacts of the many planned dams on Sa??o Francisco River, Brazil, migratory fishes because fish migrations are poorly known. We conducted a study on zulega Prochilodus argenteus, an important commercial and recreational fish in the Sa??o Francisco River, to identify migrations and spawning areas and to determine linear home range. During two spawning seasons (2001-2003), we radio-tagged fish in three main-stem reaches downstream of Tre??s Marias Dam (TMD), located at river kilometer (rkm) 2,109. We tagged 10 fish at Tre??s Marias (TM), which is 5 km downstream of TMD; 12 fish at Pontal, which is 28 km downstream of TMD and which includes the mouth of the Abaete?? River, and 10 fish at Cilga, which is 45 km downstream of TMD. Late-stage (ripe) adults tagged in each area during the spawning season remained at or near the tagging site, except for four Cilga fish that went to Pontal and probably spawned. The Pontal area at the Abaete?? River mouth was the most important spawning site we found. Prespawning fish moved back and forth between main-stem staging areas upstream of the Abaete?? River mouth and Pontal for short visits. These multiple visits were probably needed as ripe fish waited for spawning cues from a flooding Abaete?? River. Some fish homed to prespaw ning staging areas, spawning areas, and nonspawning areas. The migratory style of zulega was dualistic, with resident and migratory fish. Total linear home range was also dualistic, with small (<26-km) and large (53-127-km) ranges. The locations of spawning areas and home ranges suggest that the Pontal group (which includes Cilga fish) is one population that occupies about 110 km. The Pontal population overlaps a short distance with a population located downstream of Cilga. Movements of late-stage TM adults suggest that the TM group is a separate population, possibly with connections to populations upstream of TMD. ?? Copyright by the American Fisheries Society

  4. Channel migration of the White River in the eastern Uinta Basin, Utah and Colorado

    USGS Publications Warehouse

    Jurado, Antonio; Fields, Fred K.

    1978-01-01

    The White River is the largest stream in the southeastern part of the Uinta Basin in Utah and Colorado. This map shows the changes that have occurred in the location of the main channel of the river from 1936 to 1974. The map indicated that certain reaches of the river are subject to different rates of channel migration. Also shown is the boundary of the flood plain, which is mapped at the point of abrupt break in slope. This map documents the position of the river channel prior to any withdrawals of water or alteration of the flow characteristics of the white river that may occur in order to meet water requirements principally associated with the proposed oil-shale industry or other development in the area.The channel locations were determined from aerial photographs taken at four different time periods for the following Federal agencies: In 1936, U.S. Soil Conservation Services; 1953, U.S. Corps of Engineers; 1965, U.S. Geological Survey; and in 1974, U.S. Bureau of Land Management. The 1936 delineation, which is actually based upon photographs that were taken in 1936 and 1937, was made by projection of the original photographs on a base map that was prepared from 1:24,000 scale topographic maps. The 1953, 1965, and 1974 delineations were produced from stereographic models. The 1965 delineation was compiled from photographs that were taken during 1962-65. The delineation is labeled as 1965 for simplicity, however, because the photographs for 1965 cover about 60 percent of the study read of the river, and because no changed were discernable in those areas of repetitive photographic coverage.

  5. The dynamics of an experimental gravel bed meander with constant discharge and sediment supply

    NASA Astrophysics Data System (ADS)

    Braudrick, C. A.; Dietrich, W.; Sklar, L. S.

    2012-12-01

    As rivers meander, channel migration and cutoffs introduce continuous and episodic changes, respectively, in local boundary shear stress and bedload flux. These changes must affect the local and reach scale channel dynamics, but assessing their influence is limited by complications associated with varying discharge as well as challenging spatial and time scales. Here we explore the dynamics of a scaled-down gravel bed meandering river with constant discharge and sediment supply in a 6.1 m by 17 m long experimental flume at UC Berkeley's Richmond Field Station. The experiments are similar to Braudrick et al. (2009), but with constant rather than varying sediment supply. The flume was filled with a sorted sand with D50 of 0.85 mm, and had an initial 40 cm wide channel with a sinuosity of 1.1. Alfalfa sprouts provided bank and floodplain strength. The alfalfa was seeded by hand throughout the floodplain while a low flow provided irrigation during the 7-day alfalfa growth period. Sand (model gravel) and a lightweight plastic sediment (model sand) were fed independently from the upstream end of the flume at constant rates of 1.8 and 5 kg/hr, respectively. Despite the steady input conditions the experimental channel was quite dynamic as channel migration and bend morphology varied spatially and temporally. The sinuosity in the downstream 10 m of the flume (away from the inlet condition) increased from 1.1 to about 1.6 over the first 75 hours of the experiment, when 3 cutoffs in 29 hours decreased the sinuosity back to just over the initial value. Bank erosion was fastest when curvature was low at the beginning of the experiment and following cutoffs, and slowed once sinuosity increased. Once curvature increased the bends became asymmetric as bank erosion occurred almost exclusively at the bend apex. As the channel migrated, the local sinuosity increased, which decreasing the water surface slope and hence shear stress. The lower shear stress caused subsequent channel

  6. Meandering instability of air flow in a granular bed: self-similarity and fluid-solid duality

    PubMed Central

    Yoshimura, Yuki; Yagisawa, Yui; Okumura, Ko

    2016-01-01

    Meandering instability is familiar to everyone through river meandering or small rivulets of rain flowing down a windshield. However, its physical understanding is still premature, although it could inspire researchers in various fields, such as nonlinear science, fluid mechanics and geophysics, to resolve their long-standing problems. Here, we perform a small-scale experiment in which air flow is created in a thin granular bed to successfully find a meandering regime, together with other remarkable fluidized regimes, such as a turbulent regime. We discover that phase diagrams of the flow regimes for different types of grains can be universally presented as functions of the flow rate and the granular-bed thickness when the two quantities are properly renormalized. We further reveal that the meandering shapes are self-similar as was shown for meandering rivers. The experimental findings are explained by theory, with elucidating the physics. The theory is based on force balance, a minimum-dissipation principle, and a linear-instability analysis of a continuum equation that takes into account the fluid-solid duality, i.e., the existence of fluidized and solidified regions of grains along the meandering path. The present results provide fruitful links to related issues in various fields, including fluidized bed reactors in industry. PMID:27941823

  7. Meandering instability of air flow in a granular bed: self-similarity and fluid-solid duality.

    PubMed

    Yoshimura, Yuki; Yagisawa, Yui; Okumura, Ko

    2016-12-12

    Meandering instability is familiar to everyone through river meandering or small rivulets of rain flowing down a windshield. However, its physical understanding is still premature, although it could inspire researchers in various fields, such as nonlinear science, fluid mechanics and geophysics, to resolve their long-standing problems. Here, we perform a small-scale experiment in which air flow is created in a thin granular bed to successfully find a meandering regime, together with other remarkable fluidized regimes, such as a turbulent regime. We discover that phase diagrams of the flow regimes for different types of grains can be universally presented as functions of the flow rate and the granular-bed thickness when the two quantities are properly renormalized. We further reveal that the meandering shapes are self-similar as was shown for meandering rivers. The experimental findings are explained by theory, with elucidating the physics. The theory is based on force balance, a minimum-dissipation principle, and a linear-instability analysis of a continuum equation that takes into account the fluid-solid duality, i.e., the existence of fluidized and solidified regions of grains along the meandering path. The present results provide fruitful links to related issues in various fields, including fluidized bed reactors in industry.

  8. Meandering instability of air flow in a granular bed: self-similarity and fluid-solid duality

    NASA Astrophysics Data System (ADS)

    Yoshimura, Yuki; Yagisawa, Yui; Okumura, Ko

    2016-12-01

    Meandering instability is familiar to everyone through river meandering or small rivulets of rain flowing down a windshield. However, its physical understanding is still premature, although it could inspire researchers in various fields, such as nonlinear science, fluid mechanics and geophysics, to resolve their long-standing problems. Here, we perform a small-scale experiment in which air flow is created in a thin granular bed to successfully find a meandering regime, together with other remarkable fluidized regimes, such as a turbulent regime. We discover that phase diagrams of the flow regimes for different types of grains can be universally presented as functions of the flow rate and the granular-bed thickness when the two quantities are properly renormalized. We further reveal that the meandering shapes are self-similar as was shown for meandering rivers. The experimental findings are explained by theory, with elucidating the physics. The theory is based on force balance, a minimum-dissipation principle, and a linear-instability analysis of a continuum equation that takes into account the fluid-solid duality, i.e., the existence of fluidized and solidified regions of grains along the meandering path. The present results provide fruitful links to related issues in various fields, including fluidized bed reactors in industry.

  9. Influences of body size and environmental factors on autumn downstream migration of bull trout in the Boise River, Idaho

    USGS Publications Warehouse

    Monnot, L.; Dunham, J.B.; Hoem, T.; Koetsier, P.

    2008-01-01

    Many fishes migrate extensively through stream networks, yet patterns are commonly described only in terms of the origin and destination of migration (e.g., between natal and feeding habitats). To better understand patterns of migration in bull trout,Salvelinus confluentus we studied the influences of body size (total length [TL]) and environmental factors (stream temperature and discharge) on migrations in the Boise River basin, Idaho. During the autumns of 2001-2003, we tracked the downstream migrations of 174 radio-tagged bull trout ranging in size from 21 to 73 cm TL. The results indicated that large bull trout (>30 cm) were more likely than small fish to migrate rapidly downstream after spawning in headwater streams in early autumn. Large bull trout also had a higher probability of arriving at the current terminus of migration in the system, Arrowrock Reservoir. The rate of migration by small bull trout was more variable and individuals were less likely to move into Arrowrock Reservoir. The rate of downstream migration by all fish was slower when stream discharge was greater. Temperature was not associated with the rate of migration. These findings indicate that fish size and environmentally related changes in behavior have important influences on patterns of migration. In a broader context, these results and other recent work suggest, at least in some cases, that commonly used classifications of migratory behavior may not accurately reflect the full range of behaviors and variability among individuals (or life stages) and environmental conditions. ?? Copyright by the American Fisheries Society 2008.

  10. Migrations and swimming capabilities of endangered pallid sturgeon (Scaphirhynchus albus) to guide passage designs in the fragmented Yellowstone River

    USGS Publications Warehouse

    Braaten, P. J.; Elliott, Caroline M.; Rhoten, Jason C.; Fuller, D. B.; McElroy, Brandon J.

    2015-01-01

    Fragmentation of the Yellowstone River is hypothesized to preclude recruitment of endangered Scaphirhynchus albus (pallid sturgeon) by impeding upstream spawning migrations and access to upstream spawning areas, thereby limiting the length of free-flowing river required for survival of early life stages. Building on this hypothesis, the reach of the Yellowstone River affected by Intake Diversion Dam (IDD) is targeted for modification. Structures including a rock ramp and by-pass channel have been proposed as restoration alternatives to facilitate passage. Limited information on migrations and swimming capabilities of pallid sturgeon is available to guide engineering design specifications for the proposed structures. Migration behavior, pathways (channel routes used during migrations), and swimming capabilities of free-ranging wild adult pallid sturgeon were examined using radiotelemetry, and complemented with hydraulic data obtained along the migration pathways. Migrations of 12–26% of the telemetered pallid sturgeon population persisted to IDD, but upstream passage over the dam was not detected. Observed migration pathways occurred primarily through main channel habitats; however, migrations through side channels up to 3.9 km in length were documented. The majority of pallid sturgeon used depths of 2.2–3.4 m and mean water velocities of 0.89–1.83 m/s while migrating. Results provide inferences on depths, velocities, and habitat heterogeneity of reaches successfully negotiated by pallid sturgeon that may be used to guide designs for structures facilitating passage at IDD. Passage will provide connectivity to potential upstream spawning areas on the Yellowstone River, thereby increasing the likelihood of recruitment for this endangered species.

  11. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 1997 Annual Report.

    SciTech Connect

    Achord, Stephen; Eppard, M. Brad; Hockersmith, Eric E.

    1998-05-01

    In August 1996, we PIT tagged and released 1,360 wild chinook salmon parr in the South Fork of the Salmon River and two of its tributaries in Idaho. During spring and summer 1997, the overall adjusted percentage of PIT-tagged fish from Idaho detected at six downstream dams averaged 18.3% (range 16.0 to 27.3% depending on stream of origin). Peak detections of all wild spring/summer chinook salmon smolts (from Idaho and Oregon) at Lower Granite Dam occurred during variable but increasing river flows in April. High river flows from mid-April to mid-May moved most of these fish through Lower Granite Dam, with 50 and 90% passage occurring on 24 April and 21 May, respectively. From 1989 to 1996, peak detections of wild spring/summer chinook salmon smolts were highly variable and generally independent of river flows before about 9 May at this dam; however, during these years (including 1997), peak detections of wild fish coincided with periods of peak flow at the dam from 9 May to the end of May. In both 1995 and 1996, in excess of 90% of the wild fish had migrated past Lower Granite Dam by the time peak flows occurred in June. In 1989, we observed a period of peak detections of wild fish that coincided with peak flows at the dam in June. After examining chinook salmon smolt passage timing at the dams over the last 9 years, it has become clear that flow is only one of several factors that influence passage timing. Other factors, such as annual climatic conditions, water temperature, turbidity, physiological development, variability in stock behavior, fish size, and other yet unknown conditions may equally affect wild smolt passage timing at dams. As additional environmental monitors and traps are installed in study streams, we will be able to more accurately monitor parr and smolt movements out of rearing areas and examine the relationships of these movements to environmental parameters within the streams. Mapped over time, this information will provide the basis for

  12. Survival of migrating Atlantic salmon smolts through the Penobscot River, Maine: A pre-restoration assessment

    USGS Publications Warehouse

    Zydlewski, Joseph; Kinnison, Michael T.; Holbrook, Christopher M.

    2011-01-01

    Survival, distribution, and behavior of hatchery (n = 493) and naturally reared (n = 133) smolts of Atlantic salmon Salmo salar migrating through the Penobscot River and estuary in Maine were evaluated with acoustic telemetry in 2005 and 2006. Survival and use of a secondary migration path (the Stillwater Branch) were estimated with a multistate mark–recapture model. Higher rates of mortality per kilometer (range = 0.01–0.22) were observed near release sites and within reaches that contained three particular dams: Howland, West Enfield, and Milford dams. Estimated total survival of tagged hatchery smolts through entire individual reaches containing those dams ranged from 0.52 ( 0.18) to 0.94 ( 0.09), whereas survival through most of the reaches without dams exceeded 0.95. Of those smolts that survived to the Penobscot River–Stillwater Branch split at Marsh Island, most (≥74%) remained in the main stem around Marsh Island, where they experienced lower survival than fish that used the Stillwater Branch. Movement rates of hatchery-reared smolts were significantly lower through reaches containing dams than through reaches that lacked dams. Smolts arriving at dams during the day experienced longer delays than smolts arriving at night. Planned removal of two dams in this system is expected to enhance the passage of smolts through the main-stem corridor. However, the dams currently scheduled for removal (Great Works and Veazie dams) had less influence on smolt survival than some of the dams that will remain. This case study shows that by examining prerestoration migration dynamics throughout entire river systems rather than just in the vicinity of particular dams, tracking studies can help prioritize restoration efforts or predict the costs and benefits of future hydrosystem changes.

  13. Recruitment of Anguilla spp. glass eels in the Waikato River, New Zealand. Evidence of declining migrations?

    PubMed

    Jellyman, D J; Booker, D J; Watene, E

    2009-06-01

    The timing of Anguilla spp. glass eel recruitment into the Waikato River, North Island, New Zealand, was studied over a 2 year period (2004-2005). While glass eels of both the shortfin eel Anguilla australis and the endemic longfin eel Anguilla dieffenbachii were caught, the former comprised >97% of the species composition. There was a positive correlation of glass eel migrations with spring tides, with peak migration periods typically occurring within a few hours of the peak of high tide, and between 2 and 4 days after the day of spring tide. Both water temperature and discharge had significant inverse relationships with glass eel catches, with temperature explaining >30% of the variance in catch periodicity. Comparison of catch data 30 years apart showed that main migration periods appear to occur several weeks earlier today than previously. Reduced catch per unit effort and duration of runs from recent years' sampling (compared with the 1970s) indicate that a reduction in recruitment may also have occurred during this period, something recorded in other temperate species of Anguilla.

  14. Characterization of Wind Meandering in Low-Wind-Speed Conditions

    NASA Astrophysics Data System (ADS)

    Mortarini, Luca; Stefanello, Michel; Degrazia, Gervasio; Roberti, Debora; Trini Castelli, Silvia; Anfossi, Domenico

    2016-10-01

    Investigation of low-wind cases observed during the Urban Turbulent Project campaign (Torino, Italy) and at the Santa Maria meteorological station (Santa Maria, Brazil) provides insight into the wind-meandering phenomenon, i.e. large, non-turbulent oscillations of horizontal wind speed and temperature. Meandering and non-meandering cases are identified through analysis of the Eulerian autocorrelation functions of the horizontal wind-velocity components and temperature. When all three autocorrelation functions oscillate, meandering is present. As with weak turbulence, meandering shows no dependence on stability but is influenced by presence of buildings and depends on wind speed. We show that, while the standard deviation of the horizontal velocity is always large in low-wind conditions, the standard deviation of the vertical velocity shows very different behaviour in meandering and non-meandering conditions. In particular, the value of the ratio of the standard deviations of the vertical and horizontal velocities typifies the meandering condition.

  15. Sex biased survival and differences in migration of wild steelhead (Oncorhynchus mykiss) smolts from two coastal Oregon rivers

    USGS Publications Warehouse

    Thompson, Neil F.; Leblanc, Camille A.; Romer, Jeremy D.; Schreck, Carl B.; Blouin, Michael S.; Noakes, David L. G.

    2016-01-01

    In salmonids with partial migration, females are more likely than males to undergo smoltification and migrate to the ocean (vs. maturing in freshwater). However, it is not known whether sex affects survivorship during smolt migration (from fresh water to entry into the ocean). We captured wild steelhead (Oncorhynchus mykiss) smolts in two coastal Oregon rivers (USA) and collected fin tissue samples for genetic sex determination (2009; N = 70 in the Alsea and N = 69 in the Nehalem, 2010; N = 25 in the Alsea). We implanted acoustic tags and monitored downstream migration and survival until entry in to the Pacific Ocean. Survival was defined as detection at an estuary/ocean transition array. We found no effect of sex on smolt survivorship in the Nehalem River in 2009, or in the Alsea River in 2010. However, males exhibited significantly lower survival than females in the Alsea River during 2009. Residency did not influence this result as an equal proportion of males and females did not reach the estuary entrance (11% of males, 9% of females). The sexes did not differ in timing or duration of migration, so those variables seem unlikely to explain sex-biased survivorship. Larger males had higher odds of survival than smaller males in 2009, but the body size of females did not affect survivorship. The difference in survivorship between years in the Alsea River could be due to flow conditions, which were higher in 2010 than in 2009. Our findings suggest that sex may affect steelhead smolt survival during migration, but that the difference in survivorship may be weak and not a strong factor influencing adult sex ratios.

  16. Fluvial responses to late Quaternary climate change in the Shiyang River drainage system, western China

    NASA Astrophysics Data System (ADS)

    Gao, Hongshan; Li, Zongmeng; Pan, Baotian; Liu, Fenliang; Liu, Xiaopeng

    2016-04-01

    As a drainage system located in arid western China, the Shiyang River, combined with considerable fluvial strata and landform information, provides an environmental context within which to investigate fluvial responses to late Quaternary climate change. Sedimentological analysis and optically stimulated luminescence (OSL) dating enabled us to reconstruct the processes and fluvial styles of three sedimentary sequences of the Shagou and Hongshui rivers in the Shiyang drainage system. Our results present a variety of river behaviors during the late Quaternary in these areas. In the upstream Shiyang River, Zhangjiadazhuang (ZJDZ) profile of the Shagou was dominated by aggradation and a meandering channel pattern at 10.6-4.2 ka, while a noticeable channel incision occurred at ~ 4.2 ka followed by lateral channel migration. In the downstream Shiyang River, Datugou (DTG) profile of the Hongshui was an aggrading meandering river from 39.7 to 7.2 ka while channel incision occurred at 7.2 ka. Another downstream profile, Wudunwan (WDW) of the Hongshui was also characterized by aggradation from 22.4 to 4.8 ka; however, its channel pattern shifted from braided to meandering at ~ 13 ka. A discernable downcutting event occurred at ~ 4.8 ka, followed by three channel aggradation and incision episodes prior to 1.8 ka. The last 1.8 ka has been characterized by modern channel and floodplain development. The fluvial processes and styles investigated have a close correlation with late Quaternary climate change in the Shiyang River drainage. During cold phases, the WDW reach was dominated by aggradation with a braided channel pattern. During warm phases, the rivers that we investigated were also characterized by aggradation but with meandering channel patterns. Channel incision events and changes of fluvial style occurred mainly during climate transitions.

  17. Summary of Migration and Survival Data from Radio-Tagged Juvenile Coho Salmon in the Trinity River, Northern California, 2008

    USGS Publications Warehouse

    Beeman, John W.; Hansel, Hal; Juhnke, Steve; Stutzer, Greg

    2009-01-01

    The survival of hatchery-origin juvenile coho salmon from the Trinity River Hatchery was estimated as they migrated seaward through the Trinity and Klamath Rivers. The purpose of the study was to collect data for comparison to a similar study in the Klamath River and provide data to the Trinity River Restoration Program. A total of 200 fish fitted with radio transmitters were released into the Trinity River near the hatchery (river kilometer 252 from the mouth of the Klamath River) biweekly from March 19 to May 28, 2008. Fish from the earliest release groups took longer to pass the first detection site 10 kilometers downstream of the hatchery than fish from the later release groups, but travel times between subsequent sites were often similar among the release groups. The travel times of individuals through the 239 kilometer study area ranged from 15.5 to 84.6 days with a median of 43.3 days. The data and models did not support differences in survival among release groups, but did support differences among river reaches. The probability of survival in the first 53 kilometers was lower than in the reaches farther downstream, which is similar to trends in juvenile coho salmon in the Klamath River. The lowest estimated survival in this study was in the first 10 kilometers from release in the Trinity River (0.676 SE 0.036) and the highest estimated survival was in the final 20 kilometer reach in the Klamath River (0.987 SE 0.013). Estimated survivals of radio-tagged juvenile coho salmon from release to Klamath River kilometer 33 were 0.639 per 100 kilometers for Trinity River fish and 0.721 per 100 kilometers for Klamath River fish.

  18. Prevalence of Renibacterium salmoninarum among downstream-migrating salmonids in the Columbia River

    USGS Publications Warehouse

    Sanders, J.E.; Long, J.J; Arakawa, C.K.; Bartholomew, J.L.; Rohovec, J.S.

    1992-01-01

    Bacterial kidney disease (BKD) is an important contributor to mortality of salmonids in hatcheries in the Columbia River basin. However, the impact of BKD on the survival of downstream migrants is difficult to determine because there is little information on the disease-related mortality among these fish. In this study, the impact of BKD on juvenile salmonids was examined by determining the percentage of downriver migrants infected with Renibacterium salmoninarum (the causative agent of BKD) and evaluating the effects of salt water on the progress of the disease. During the 2 years of this study, approximately 20% of the three species of migrating hatchery and wild salmonids (Oncorhynchus spp.) collected were infected with R. salmoninarum. Mortality caused by BKD increased when fish were held in salt water.

  19. EMG telemetry studies on upstream migration of chum salmon in the Toyohira River, Hokkaido, Japan.

    PubMed

    Makiguchi, Yuya; Konno, Yoshifumi; Konishi, Koji; Miyoshi, Koji; Sakashita, Taku; Nii, Hisaya; Nakao, Katsuya; Ueda, Hiroshi

    2011-06-01

    The movements of 28 adult chum salmon, Oncorhynchus keta (Walbaum) tagged with electromyogram (EMG) transmitters were tracked along the Toyohira river, Hokkaido, Japan, in October of 2007 and 2008 to investigate and evaluate the upstream migratory behavior through the protection bed and fishway of ground sills. The approach time of fish that ascended successfully through the protection bed and fishway was shorter than that of unsuccessful fish. The unsuccessful fish were observed to swim in currents with high water velocity and shallow water depth at swimming speeds that exceeded their critical swimming speed (U (crit)) during the approach to these structures. In consequence, unsuccessful fish frequently alternated between burst and maximum sustained speeds without ever ascending the fishway, and eventually became exhausted. It is important that fishway are constructed to enable chum salmon to find a passage way easily, so that they can migrate upstream rapidly without wasting excessive energy.

  20. Sediment transport and morphodynamic changes in Ziarat Estuary and Mond River Delta, the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Razavi Arab, Azadeh; Haghshenas, S. Abbas; Samsami, Farzin

    2014-05-01

    The Mond River, which is considered as one of the Major Iranian rivers discharging in to the Persian Gulf, is bounded within the region from 51°10' to 54°28' E and 27°20' to 29°51' N, flowing in two provinces of Fars and Boushehr. The latest part of the river is completely meandered and the river mouth has been migrating twice during the past 50 years. Total sediment discharge of the river is estimated as 12 million cubic meter per year. Analysis of meandering river phenomenon and river mouth migration as well as evolution of the down-stream sand spits has long been one of the challenges in hydrodynamic discussions. This natural process usually takes place in rivers to provide energy equilibrium and its integration with human desires has posed as a management issue. The sediment discharging to the Persian Gulf plays an essential role in formation of Mond River Delta as well as a set of sand spits formed in downstream of the river mouth. The morpho-dynamic of entire environment of the Mond River - Mond Delta highly affects marine environment in the surrounding area. The present study offers the results of a numerical and field investigation of various features of river-delta interaction on Ziarat Estuary and the Mond Delta area. A numerical model has been utilized to investigate cases of flow and sediment transport behaviour in the coastal Mond area and future migration patterns of the River Mouth is estimated. Sediment sources and relevant contributions in morphodynamic changes of the sand spits are widely investigated through sediment constituent analysis. The results of the numerical model are compared with field observations and comprehensive GIS based analysis of historic shoreline changes from aerial photos and satellite imagery. It is concluded that the model achievements are capable to predict the observed phenomena. Management guidelines and suggestions are deducted and drawn from the calibration and verification of the results with field observations

  1. Chlorinated river and lake water extract caused oxidative damage, DNA migration and cytotoxicity in human cells.

    PubMed

    Yuan, Jing; Wu, Xin-Jiang; Lu, Wen-Qing; Cheng, Xiao-Li; Chen, Dan; Li, Xiao-Yan; Liu, Ai-Lin; Wu, Jian-Jun; Xie, Hong; Stahl, Thorsten; Mersch-Sundermann, Volker

    2005-01-01

    Consumption of chlorinated drinking water is suspected to be associated with adverse health effects, including mutations and cancer. In the present study, the genotoxic potential of water from Donghu lake, Yangtze river and Hanjiang river in Wuhan, an 8-million metropolis in China, was investigated using HepG2 cells and the alkaline version of the comet assay. It could be shown that all water extracts caused dose-dependent DNA migration in concentrations corresponding to dried extracts of 0.167-167 ml chlorinated drinking water per ml medium. To explore whether the intracellular redox status is regulated by chlorinated drinking water, we determined lipid peroxidation (LPO) and depletion of reduced glutathione (GSH). The malondialdehyde (thiobarbituric acid (TBA)-reactive aldehydes) concentration increased after chlorinated drinking water treatment of HepG2 cells in a dose-dependent manner, the GSH content decreased. The activity of lactate dehydrogenase (LDH) increased in chlorinated drinking water treated HepG2 cells indicating cytotoxicity. In accordance with former studies which dealt with in vivo and in vitro micronucleus induction the present study shows that chlorinated drinking water from polluted raw water may entail genetic risks.

  2. Effect of Migration Pathway on Travel Time and Survival of Acoustic-Tagged Juvenile Salmonids in the Columbia River Estuary

    SciTech Connect

    Harnish, Ryan A.; Johnson, Gary E.; McMichael, Geoffrey A.; Hughes, Michael S.; Ebberts, Blaine D.

    2012-02-01

    Off-channel areas (side channels, tidal flats, sand bars, and shallow-water bays) may serve as important migration corridors through estuarine environments for salmon and steelhead smolts. Relatively large percentages (21-33%) of acoustic-tagged yearling and subyearling Chinook salmon and steelhead smolts were detected migrating through off-channel areas of the Columbia River estuary in 2008. The probability of survival for off-channel migrants (0.78-0.94) was similar to or greater than the survival probability of main channel migrants (0.67-0.93). Median travel times were similar for all species or run types and migration pathways we examined, ranging from 1-2 d. The route used by smolts to migrate through the estuary may affect their vulnerability to predation. Acoustic-tagged steelhead that migrated nearest to avian predator nesting colonies experienced higher predation rates (24%) than those that migrated farthest from the colonies (10%). The use of multiple migration pathways may be advantageous to out-migrating smolts because it helps to buffer against high rates of mortality, which may occur in localized areas, and helps to minimize inter- and intraspecific competition.

  3. Simulation of Helical Flow Hydrodynamics in Meanders and Advection-Turbulent Diffusion Using Smoothed Particle Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Gusti, T. P.; Hertanti, D. R.; Bahsan, E.; Soeryantono, H.

    2013-12-01

    Particle-based numerical methods, such as Smoothed Particle Hydrodynamics (SPH), may be able to simulate some hydrodynamic and morphodynamic behaviors better than grid-based numerical methods. This study simulates hydrodynamics in meanders and advection and turbulent diffusion in straight river channels using Microsoft Excel and Visual Basic. The simulators generate three-dimensional data for hydrodynamics and one-dimensional data for advection-turbulent diffusion. Fluid at rest, sloshing, and helical flow are simulated in the river meanders. Spill loading and step loading are done to simulate concentration patterns associated with advection-turbulent diffusion. Results indicate that helical flow is formed due to disturbance in morphology and particle velocity in the stream and the number of particles does not have a significant effect on the pattern of advection-turbulent diffusion concentration.

  4. Ontogenetic behavior and migration of Volga River Russian sturgeon, Acipenser gueldenstaedtii, with a note on adaptive significance of body color

    USGS Publications Warehouse

    Kynard, B.; Zhuang, P.; Zhang, L.; Zhang, T.; Zhang, Z.

    2002-01-01

    We conducted laboratory experiments with Volga River Russian sturgeon, Acipenser gueldenstaedtii, to develop a conceptual model of early behavior. We daily observed fish from day-0 (embryos, first life interval after hatching) to day-29 feeding larvae for preference of bright habitat and cover, swimming distance above the bottom, up- and downstream movement, and diel activity. Hatchling embryos initiated a downstream migration, which suggests that predation risk of embryos at spawning sites is high. Migration peaked on days 0-5 and ceased on day 7 (8-day migration). Migrants preferred bright, open habitat and early migrants swam-up far above the bottom (maximum daily median, 140 cm) in a vertical swim tube. Post-migrant embryos did not prefer bright illumination but continued to prefer white substrate, increased use of cover habitat, and swam on the bottom. Larvae initiated feeding on day 10 after 170.6 cumulative temperature degree-days. Larvae did not migrate, weakly preferred bright illumination, preferred white substrate and open habitat, and swam near the bottom (daily median 5-78 cm). The lack of a strong preference by larvae for bright illumination suggests foraging relies more on olfaction than vision for locating prey. A short migration by embryos would disperse wild sturgeon from a spawning area, but larvae did not migrate, so a second later migration by juveniles disperses young sturgeon to the sea (2-step migration). Embryo and larva body color was light tan and tail color was black. The migration, behavior, and light body color of Russian sturgeon embryos was similar to species of Acipenser and Scaphirhynchus in North America and to Acipenser in Asia that migrate after hatching as embryos. The similarity in migration style and body color among species with diverse phylogenies likely reflects convergence for common adaptations across biogeographic regions. ?? 2002 Kluwer Academic Publishers.

  5. [Modeling of Processes of Migration and Accumulation of Radionuclides in Freshwater Ecosystems by the Example of the Samson, Lev, Vandras Rivers Related to the Ob-Irtysh River Basin].

    PubMed

    Trapeznikov, A V; Korzhavin, A V; Trapeznikova, V N; Nikolkin, V N

    2016-01-01

    Mathematical models of horizontal distribution and migration of radionuclides are presented in water and floodplain soils of the Samson-Lev-Vandras river system related to the Ob-Irtysh river basin. Integral inventory of radionuclides in the main components of the river ecosystems is calculated. The estimated annual discharge of radionuclides from the Vandras river to the Great Salym river is given. The effect of the removal of man-made radionuclides in the Samson, Lev, Vandras rivers on radioactive contamination of the Ob-Irtysh river system is shown in comparison with the Techa river, that also belongs to the Ob-Irtysh river basin. Despite the presence of an additional radioactive contamination of the Samson floodplain, the transfer of radioactive substances in the Samson, Lev, Vandras rivers has a much smaller impact on the contamination of the Ob-Irtysh river system, compared to the Techa river, prone to a large-scale radioactive contamination.

  6. Patterns of migration and residency in coastal cutthroat trout Oncorhynchus clarkii clarkii from two tributaries of the lower Columbia River.

    PubMed

    Zydlewski, G B; Zydlewski, J; Johnson, J

    2009-07-01

    Coastal cutthroat trout Onchorhynchus clarkii clarkii life-history variants, migration and freshwater residency were monitored using stationary passive integrated transponder (PIT) tag arrays in two tributaries of the Columbia River from 2001 to 2005 (Abernathy Creek, river kilometre, rkm 76) and from 2002 to 2005 (Chinook River, rkm 6). In 2001-2003 and 2002-2003 (Abernathy and Chinook, respectively), 300-500 coastal O. c. clarkii were captured in each tributary by electrofishing and implanted with 23 mm PIT tags. PIT arrays monitored movements from the initiation of tagging through the spring of 2005. Rotary screw traps were also operated on both tributaries. In Abernathy Creek, 28% of tagged individuals were observed through either active capture or passive interrogation. Of these, 32% were identified as migrants and 68% were identified as residents. In the Chinook River, 48% of tagged fish were observed subsequent to tagging; 92% of these fish were migrants and only 8% were resident. In both tributaries, a greater proportion of resident fish were in the upper reaches. The majority of migrants (78-93%) moved the spring following tagging. Migrants leaving at age 2+ years tended to grow faster than those that migrated at age 3+ years or residents. Patterns of growth or growth opportunities may influence both patterns of life-history expression and the timing of migration.

  7. Patterns of migration and residency in coastal cutthroat trout Oncorhynchus clarkii clarkii from two tributaries of the lower Columbia River

    USGS Publications Warehouse

    Zydlewski, G.B.; Zydlewski, J.; Johnson, J.

    2009-01-01

    Coastal cutthroat trout Onchorhynchus clarkii clarkii life-history variants, migration and freshwater residency were monitored using stationary passive integrated transponder (PIT) tag arrays in two tributaries of the Columbia River from 2001 to 2005 (Abernathy Creek, river kilometre, rkm 76) and from 2002 to 2005 (Chinook River, rkm 6). In 2001-2003 and 2002-2003 (Abernathy and Chinook, respectively), 300-500 coastal O. c. clarkii were captured in each tributary by electrofishing and implanted with 23 mm PIT tags. PIT arrays monitored movements from the initiation of tagging through the spring of 2005. Rotary screw traps were also operated on both tributaries. In Abernathy Creek, 28% of tagged individuals were observed through either active capture or passive interrogation. Of these, 32% were identified as migrants and 68% were identified as residents. In the Chinook River, 48% of tagged fish were observed subsequent to tagging; 92% of these fish were migrants and only 8% were resident. In both tributaries, a greater proportion of resident fish were in the upper reaches. The majority of migrants (78-93%) moved the spring following tagging. Migrants leaving at age 2+ years tended to grow faster than those that migrated at age 3+ years or residents. Patterns of growth or growth opportunities may influence both patterns of life-history expression and the timing of migration. ?? 2009 The Fisheries Society of the British Isles.

  8. Migration and spawning of female surubim (Pseudoplatystoma corruscans, Pimelodidae) in the São Francisco river, Brazil

    USGS Publications Warehouse

    Godinho, Alexandre L.; Kynard, Boyd; Godinho, Hugo P.

    2007-01-01

    Surubim, Pseudoplatystoma corruscans, is the most valuable commercial and recreational fish in the São Francisco River, but little is known about adult migration and spawning. Movements of 24 females (9.5–29.0 kg), which were radio-tagged just downstream of Três Marias Dam (TMD) at river kilometer 2,109 and at Pirapora Rapids (PR) 129 km downstream of TMD, suggest the following conceptual model of adult female migration and spawning. The tagged surubims used only 274 km of the main stem downstream of TMD and two tributaries, the Velhas and Abaeté rivers. Migration style was dualistic with non-migratory (resident) and migratory fish. Pre-spawning females swam at ground speeds of up to 31 km day-1 in late September–December to pre-spawning staging sites located 0–11 km from the spawning ground. In the spawning season (November–March), pre-spawning females migrated back and forth from nearby pre-spawning staging sites to PR for short visits to spawn, mostly during floods. Multiple visits to the spawning site suggest surubim is a multiple spawner. Most post-spawning surubims left the spawning ground to forage elsewhere, but some stayed at the spawning site until the next spawning season. Post-spawning migrants swam up or downstream at ground speeds up to 29 km day-1 during January–March. Construction of proposed dams in the main stem and tributaries downstream of TMD will greatly reduce surubim abundance by blocking migrations and changing the river into reservoirs that eliminate riverine spawning and non-spawning habitats, and possibly, cause extirpation of populations.

  9. Mathematical analysis and validation of an exactly solvable model for upstream migration of fish schools in one-dimensional rivers.

    PubMed

    Yoshioka, Hidekazu

    2016-11-01

    Upstream migration of fish schools in 1-D rivers as an optimal control problem is formulated where their swimming velocity and the horizontal oblateness are taken as control variables. The objective function to be maximized through a migration process consists of the biological and ecological profit to be gained at the upstream-end of a river, energetic cost of swimming against the flow, and conceptual cost of forming a school. Under simplified conditions where the flow is uniform in both space and time and the profit to be gained at the goal of migration is sufficiently large, the optimal control variables are determined from a system of algebraic equations that can be solved in a cascading manner. Mathematical analysis of the system reveals that the optimal controls are uniquely found and the model is exactly solvable under certain conditions on the functions and parameters, which turn out to be realistic and actually satisfied in experimental fish migration. Identification results of the functional shapes of the functions and the parameters with experimentally observed data of swimming schools of Plecoglossus altivelis (Ayu) validate the present mathematical model from both qualitative and quantitative viewpoints. The present model thus turns out to be consistent with the reality, showing its potential applicability to assessing fish migration in applications.

  10. Songbird use of floodplain and upland forests along the Upper Mississippi River corridor during spring migration

    USGS Publications Warehouse

    Kirsch, Eileen M.; Heglund, Patricia J.; Gray, Brian R.; Mckann, Patrick

    2013-01-01

    The Upper Mississippi River is thought to provide important stopover habitat for migrating landbirds because of its north-south orientation and floodplain forests. The river flows through the Driftless Area of southwestern Wisconsin and southeastern Minnesota where forests are plentiful, yet forests of the floodplain and Driftless Area uplands differ greatly in landscape setting, tree species composition, and topography. We compared landbird assemblages in these upland and floodplain forests over three springs, 2005–2007, using line-transect surveys at randomly selected areas in and within 16 km of the floodplain. We found more species of both transient and locally breeding migrants per survey in floodplain than in upland forest. Detections of transient neotropical migrants did not differ statistically by habitat. Detections of locally breeding neotropical and temperate-zone migrants and transient temperate-zone migrants were greater in floodplain than in upland forest. Between floodplain and upland forest, assemblages of locally breeding species, including neotropical and temperate-zone migrants (of which some individuals were in transit), differed substantially, but assemblages of transients (including both neotropical and temperate-zone migrants) did not differ as much. Only two species of transient migrants had clear affinities for floodplain forest, and none had an affinity for upland forest, whereas most locally breeding migrants had an affinity for either upland or floodplain forest. Within each spring, however, detections of transient neotropical migrants shifted from being greater in floodplain to greater in upland forests. This intraseasonal shift may be related to the phenology of certain tree species.

  11. Synchronous cycling of Ichthyophoniasis with Chinook salmon density revealed during the annual Yukon River spawning migration

    USGS Publications Warehouse

    Zuray, Stanley; Kocan, Richard; Hershberger, Paul

    2012-01-01

    Populations of Chinook salmon Oncorhynchus tshawytscha in the Yukon River declined by more than 57% between 2003 and 2010, probably the result of a combination of anthropogenic and environmental factors. One possible contributor to this decline is Ichthyophonus, a mesomycetozoan parasite that has previously been implicated in significant losses of fish, including Chinook salmon. A multiyear epidemiological study of ichthyophoniasis in the Yukon River revealed that disease prevalence and Chinook salmon population abundance increased and decreased simultaneously (i.e., were concordant) from 1999 to 2010. The two values rose and fell synchronously 91% of the time for female Chinook salmon and 82% of the time for males; however, there was no significant correlation between Ichthyophonus prevalence and population abundance. This synchronicity might be explained by a single factor, such as a prey item that is critical to Chinook salmon survival as well as a source of Ichthyophonus infection. The host–parasite relationship between Ichthyophonus and migrating Chinook salmon from 2004 to 2010 was similar to that reported for the previous 5 years. During 2004–2010, overall disease prevalence was significantly higher among females (21%) than among males (8%), increased linearly with fish length for both males and females, and increased in both sexes as the fish progressed upriver. These regularly occurring features of host–parasite dynamics confirm a stable base of transmission for Ichthyophonus. However, from 2003 to 2010, disease prevalence decreased from 30% to just 8% in males and from 45% to 9% in females, paralleling a similar decline in Chinook salmon abundance during the same period. These findings may help clarify questions regarding the complex host–parasite dynamics that occur in marine species such as herrings Clupea spp., which have less well-defined population structures.

  12. Migration and degradation of swine farm tetracyclines at the river catchment scale: Can the multi-pond system mitigate pollution risk to receiving rivers?

    PubMed

    Chen, Qiuwen; Guo, Xiao; Hua, Guofen; Li, Guoliang; Feng, Ranran; Liu, Xiaoli

    2017-01-01

    The study investigated the degradation behaviors of swine farm tetracyclines (TCs) at a catchment scale and explored whether multi-pond systems could be beneficial to the interception of TCs so as to reduce the pollution risk to receiving rivers. The occurrence and migration of 12 kinds of tetracycline antibiotics, including their degradation products, were studied in four swine farms of the Meijiang River basin in China. The migration paths of the TCs were examined through sampling and analyzing the soil and/or sediment at different points along the swine wastewater outlet, which included sewer, sewage pond, mixed-canal (stream and sewage), farmland (paddy and upland soil) and finally the river. TC concentrations of all collected samples were obtained by solid phase extraction followed by measurement with high-performance liquid chromatography tandem mass spectrometry. The results showed that sediment TC concentrations varied greatly in different swine farms, from mg·kg(-1) to μg·kg(-1) levels. TCs had different decay patterns along different migration paths, such that TCs decayed exponentially in paddy soil, while linearly in sewer and mixed canal. The concentrations of TCs and their degradation products decreased in the order: sewer sediment > sewage pond sediment > mixed-canal sediment > paddy soil > upland soil, indicating that TCs tend to be more easily intercepted and accumulated in water-sediment systems such as ponds. Therefore, the multi-pond system could be an effective way to prevent TCs from migrating into rivers. These results provided essential information for contamination control of antibiotics in aquatic environments.

  13. Numerically Simulating the Hydrodynamic and Water Quality Environment for Migrating Salmon in the Lower Snake River

    SciTech Connect

    Cook, Chris B.; Richmond, Marshall C.; Coleman, Andre M.; Rakowski, Cynthia L.; Titzler, P. Scott; Bleich, Matthew D.

    2003-06-10

    Summer temperatures in the Lower Snake River can be altered by releasing cold waters that originate from deep depths within Dworshak Reservoir. These cold releases are used to lower temperatures in the Clearwater and Lower Snake Rivers, and improve hydrodynamic and water quality conditions for migrating aquatic species. This project monitored the complex three-dimensional hydrodynamic and thermal conditions at the confluence of the Clearwater and Snake Rivers and the processes that led to stratification of Lower Granite Reservoir (LGR) during the late spring, summer, and fall of 2002. Hydrodynamic, water quality, and meteorological conditions around the reservoir were monitored at frequent intervals, and this effort is currently continuing in 2003. Monitoring of the reservoir is a multi-year endeavor, and this report spans only the first year of data collection. In addition to monitoring the LGR environment, a three-dimensional hydrodynamic and water quality model has also been applied. This model uses collected field data as boundary conditions and has been applied to the entire 2002 field season. Numerous data collection sites were within the model domain and serve as both calibration and validation locations for the numerical model. Errors between observed and simulated data vary in magnitude from location to location and from one time to another. Generally, errors are small and within expected ranges, although model parameters may be improved in the future to minimize differences between observed and simulated values as additional 2003 field data become available. A two-dimensional laterally-averaged hydrodynamic and water quality model was applied to the three reservoirs downstream of LGR (the pools behind Little Goose, Lower Monumental, and Ice Harbor Dams). A two-dimensional model is appropriate for these reservoirs because observed lateral thermal variations during summer and fall 2002 were almost negligible, however vertical thermal variations were quite

  14. The persistence and characteristics of Chinook salmon migrations to the Upper Klamath River prior to exclusion by dams

    USGS Publications Warehouse

    Hamilton, John B; Rondorf, Dennis W.; Tinniswood, William; Leary, Ryan J; Mayer, Tim; Gavette, Charleen; Casal, Lynne A.

    2016-01-01

    In this research article, John Hamilton and his co-authors present extensive new research and information gathered since a 2005 publication on the historical evidence of anadromomous fish distribution in the Upper Klamath River watershed. Using historical accounts from early explorers and ethnographers to early-twentieth-century photographs, newspaper accounts, and government reports, the authors provide a more complete record of past salmon migrations. The updated record “substantiate[s] the historical persistence of salmon, their migration characteristics, and the broad population baseline that will be key to future commercial, recreational, and Tribal fisheries in the Klamath River and beyond.” During a time when salmon restoration plans are being considered in the region, the historical record can serve as guidance to once again establish diverse and thriving populations.

  15. Emergence of river dynamics through changing vegetation patterns

    NASA Astrophysics Data System (ADS)

    van Oorschot, Mijke; Kleinhans, Maarten; Middelkoop, Hans; Geerling, Gertjan

    2016-04-01

    Riparian vegetation interacts with morphodynamic processes in rivers to create distinct habitat mosaics supporting a large biodiversity. The aim of our work is to quantitatively investigate the emergent patterns in vegetation and river morphology at the river reach scale by dynamically modelling the processes and their interactions. Here, we coupled an advanced morphodynamic model to a novel dynamic riparian vegetation model to study the interaction between vegetation and morphodynamics. Vegetation colonizes bare substrate within the seed dispersal window, passes several growth stages with different properties and can die through flooding, desiccation, uprooting, scour or burial. We have compared river morphology and vegetation patterns of scenarios without vegetation, with static vegetation that does not grow or die and several dynamic vegetation scenarios with a range of vegetation strategies and eco-engineering properties. Results show that dynamic vegetation has a decreased lateral migration of meander bends and maintains its active meandering behavior as opposed to the scenarios without vegetation and with static vegetation. Also the patterns in vegetation and fluvial morphology and the vegetation age distribution mostly resemble the natural situation when compared to aerial photos of the study area. We find that river dynamics, specifically sinuosity and sediment transport, are very sensitive to vegetation properties that determine vegetation density, settlement location and survival. Future work will include the effects of invasive species, addition of silt and the effect of various river management strategies.

  16. Simulation Comparisons of Three Different Meander Line Dipoles

    DTIC Science & Technology

    2015-01-01

    Meandering is a method by which a resonant antenna can be reduced in size to fit a smaller application.1 Because resonant antennas are directly...However, continued meandering of the antenna trace introduces some detrimental effects. The biggest negative impact is the reduced reflection coefficient...that occurs when an antenna line is meandered. Each turn introduces a mutual capacitance that not only influences the resonant frequency but also

  17. Regional hydrocarbon generation, migration, and accumulation pattern of Cretaceous strata, Powder River Basin

    SciTech Connect

    Meissner, F.F.

    1985-05-01

    A cell of abnormally high fluid pressure in the deep part of the Powder River basin is centered in an area where oil-generation-prone source rocks in the Skull Creek (oldest), Mowry, and Niobrara (youngest) formations are presently at their maximum hydrocarbon-volume generation rate. The overpressures are believed to be caused by the high conversion rate of solid kerogen in the source rocks to an increased volume of potentially expellable fluid hydrocarbons. In this area, hydrocarbons appear to be the principal mobile fluid species present in reservoirs within or proximal to the actively generating source rocks. Maximum generation pressures within the source rocks have caused vertical expulsion through a pressure-induced microfracture system and have charged the first available underlying and/or overlying sandstone carrier-reservoir bed. Hydrocarbons generated in the Skull Creek have been expelled downward into the Dakota Sandstone and upward into the Muddy Sandstone. Hydrocarbons generated in the Mowry have been expelled downward into the Muddy or upward into lower Frontier sandstones. Hydrocarbons generated in the Niobrara have been expelled downward into upper Frontier sandstones or upward into the first available overlying sandstone in the Upper Cretaceous. The first chargeable sandstone overlying the Niobrara, in ascending order, may be the (1) Shannon, (2) Sussex, (3) Parkman, (4) Teapot, or (5) Tekla, depending on the east limit of each sandstone with respect to vertical fracture migration through the Cody Shale from the underlying area of mature overpressured Niobrara source rocks.

  18. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2003-2004 Annual Report.

    SciTech Connect

    Achord, Stephen; Hodge, Jacob M.; Sandford, Benjamin P.

    2005-06-01

    This report provides information on PIT-tagging of wild Chinook salmon parr in Idaho in 2003 and the subsequent monitoring of these fish and similarly tagged fish from Oregon. We report estimated parr-to-smolt survival and arrival timing of these fish at Lower Granite Dam, as well as interrogation data collected at several other sites throughout the Snake and Columbia River system. This research continues studies that began under Bonneville Power Administration (BPA) funding in 1991. Results from previous study years were reported by Achord et al. (1994; 1995a,b; 1996a; 1997; 1998; 2000; 2001a,b; 2002, 2003, 2004). Goals of this ongoing study are: (1) Characterize the migration timing and estimate parr-to-smolt survival of different stocks of wild Snake River spring/summer Chinook salmon smolts at Lower Granite Dam. (2) Determine whether consistent migration patterns are apparent. (3) Determine what environmental factors influence migration patterns. (4) Characterize the migration behavior and estimate survival of different wild juvenile fish stocks as they emigrate from their natal rearing areas. This study provides critical information for recovery planning, and ultimately recovery for these ESA-listed wild fish stocks. In 2003-2004, we also continued to measure water temperature, dissolved oxygen, specific conductance, turbidity, water depth, and pH at five monitoring stations in the Salmon River Basin, Idaho for the Baseline Environmental Monitoring Program. These data, along with parr/smolt migration, survival, and timing data, will help to discern patterns or characteristic relationships between fish movement/survival and environmental factors.

  19. Hydraulic Characteristics of the Lower Snake River during Periods of Juvenile Fall Chinook Salmon Migration, 2002-2006 Final Report.

    SciTech Connect

    Cook, C.; Dibrani, B.; Richmond, M.; Bleich, M.; Titzler, P..; Fu, T.

    2006-01-01

    This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10 C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir's epilimnion at the Clearwater/Snake River confluence is of key biological importance. Data collected during this project indicates the three reservoirs downstream of Lower Granite also stratify as direct result of flow augmentation from Dworshak Reservoir. These four reservoirs are also heavily influenced by wind forcing at the water's surface and during periods of low river discharge often behave like a two-layer lake. During these periods of stratification, lower river discharge, and wind forcing, the water in the upper layer of the reservoir is held in place or moves slightly upstream. This upper layer is also exposed to surface heating and may warm up to temperatures close to equilibrium temperature. The thickness (depth) of this upper warm layer and its direction of travel may be of key biological importance to juvenile fall Chinook

  20. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 2001-2002 Annual Report.

    SciTech Connect

    Achond, Stephen; Hockersmith, Eric E.; Sandford, Benjamin P.

    2003-07-01

    This report details the 2002 results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends in the cumulative data collected for this project from Oregon and Idaho streams since 1989. The project was initiated after detection data from passive-integrated-transponder tags (PIT tags) had shown distinct differences in migration patterns between wild and hatchery fish for three consecutive years. National Marine Fisheries Service (NMFS) investigators first observed these differences in 1989. The data originated from tagging and interrogation operations begun in 1988 to evaluate smolt transportation for the U.S. Army Corps of Engineers. In 1991, the Bonneville Power Administration began a cooperative effort with NMFS to expand tagging and interrogation of wild fish. Project goals were to characterize the outmigration timing of these fish, to determine whether consistent migration patterns would emerge, and to investigate the influence of environmental factors on the timing and distribution of these migrations. In 1992, the Oregon Department of Fish and Wildlife (ODFW) began an independent program of PIT tagging wild chinook salmon parr in the Grande Ronde and Imnaha River Basins in northeast Oregon. Since then, ODFW has reported all tagging, detection, and timing information on fish from these streams. However, with ODFW concurrence, NMFS will continue to report arrival timing of these fish at Lower Granite Dam.

  1. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2008.

    SciTech Connect

    Faulkner, James R.; Smith, Steven G.; Muir, William D.

    2009-06-23

    In 2008, the National Marine Fisheries Service completed the sixteenth year of a study to estimate survival and travel time of juvenile salmonids Oncorhynchus spp. passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder (PIT) tags. We PIT tagged and released a total of 18,565 hatchery steelhead O. mykiss, 15,991 wild steelhead, and 9,714 wild yearling Chinook salmon O. tshawytscha at Lower Granite Dam in the Snake River. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and at sites within the hydropower system in both the Snake and Columbia Rivers. These included 122,061 yearling Chinook salmon tagged at Lower Granite Dam for evaluation of latent mortality related to passage through Snake River dams. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the single-release model). Primary research objectives in 2008 were to: (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon and steelhead, (2) evaluate relationships between survival estimates and migration conditions, and (3) evaluate the survival estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2008 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Additional details on the methodology and statistical models used are provided in previous reports cited here. Survival

  2. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008

    SciTech Connect

    Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

    2009-07-09

    This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008 are: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival to Lower Granite Dam was 15.5% for the late summer/fall group, 48.0% for the winter group, and 58.5% for the spring group. Based on detections at downstream dams, the overall efficiency of VC1 (upper) or VC2 (lower) Valley Creek monitors for detecting these fish was 21.1%. Using this VC1 or VC2 efficiency, an estimated 40.8% of all summer-tagged parr survived to move out of Valley Creek, and their estimated survival from that point to Lower Granite Dam was 26.5%. Overall estimated parr-to-smolt survival for all summer-tagged parr from this stream at the dam was 12.1%. Development and improvement of instream PIT-tag monitoring systems continued throughout 2007 and 2008. (4) Testing of PIT-tag antennas in lower Big Creek during 2007

  3. Origins and impacts of mesoscale meanders in the Agulhas Current

    NASA Astrophysics Data System (ADS)

    Elipot, S.; Beal, L. M.

    2014-12-01

    The Agulhas Current (AC) is the western boundary current of the South Indian subtropical gyre and is also the pathway for the inter-basin exchange of water, heat and salt between the Indian Ocean and the Atlantic Ocean, and thus a crucial part of the global overturning circulation of the world ocean. The AC, which otherwise flows stably along the coast of South Africa, undergoes dramatic offshore excursions from its mean path, forming large mesoscale solitary meanders propagating downstream and potentially linked to the leakage of Indian Ocean waters to the South Atlantic. These irregular meander events have been referred to as Natal Pulses.Here we present new observations and analyses of Agulhas meanders using full-depth velocity mooring observations from the Agulhas Current Time series experiment (ACT). Detailed analyses of the in-situ velocity reveal important differences between the behavior of the flow during solitary meander events and during meander events of smaller amplitude. During solitary meanders, an onshore cyclonic circulation and an offshore anticyclonic circulation act in concert to displace the jet offshore, leading to sudden and strong positive conversion of kinetic energy of the mean flow to the meander. In contrast, smaller amplitude meanderings are principally represented by a single cyclonic circulation spanning the entire jet that acts to displace the jet without significantly extracting kinetic energy from the mean flow. Solitary meander events can be traced upstream using satellite altimetry and linked to either Mozambique Channel eddies or Madagascar dipoles, the latter possibly part of a basin-wide pattern of propagating sea level anomalies consistent with Rossby wave dynamics. However, only a small number of these anomalies lead to solitary meanders. Altimetric observations suggest 1.5 meanders per year and show that the two-year period during ACT when no events were observed is unprecedented in the 20-year satellite record.

  4. Foraging Ecology of Fall-Migrating Shorebirds in the Illinois River Valley

    PubMed Central

    Smith, Randolph V.; Stafford, Joshua D.; Yetter, Aaron P.; Horath, Michelle M.; Hine, Christopher S.; Hoover, Jeffery P.

    2012-01-01

    Populations of many shorebird species appear to be declining in North America, and food resources at stopover habitats may limit migratory bird populations. We investigated body condition of, and foraging habitat and diet selection by 4 species of shorebirds in the central Illinois River valley during fall migrations 2007 and 2008 (Killdeer [Charadrius vociferus], Least Sandpiper [Calidris minutilla], Pectoral Sandpiper [Calidris melanotos], and Lesser Yellowlegs [Tringa flavipes]). All species except Killdeer were in good to excellent condition, based on size-corrected body mass and fat scores. Shorebird diets were dominated by invertebrate taxa from Orders Diptera and Coleoptera. Additionally, Isopoda, Hemiptera, Hirudinea, Nematoda, and Cyprinodontiformes contribution to diets varied by shorebird species and year. We evaluated diet and foraging habitat selection by comparing aggregate percent dry mass of food items in shorebird diets and core samples from foraging substrates. Invertebrate abundances at shorebird collection sites and random sites were generally similar, indicating that birds did not select foraging patches within wetlands based on invertebrate abundance. Conversely, we found considerable evidence for selection of some diet items within particular foraging sites, and consistent avoidance of Oligochaeta. We suspect the diet selectivity we observed was a function of overall invertebrate biomass (51.2±4.4 [SE] kg/ha; dry mass) at our study sites, which was greater than estimates reported in most other food selection studies. Diet selectivity in shorebirds may follow tenants of optimal foraging theory; that is, at low food abundances shorebirds forage opportunistically, with the likelihood of selectivity increasing as food availability increases. Nonetheless, relationships between the abundance, availability, and consumption of Oligochaetes for and by waterbirds should be the focus of future research, because estimates of foraging carrying capacity

  5. The Sredne-Amursky basin: A migrating cretaceous depocenter for the Amur river, eastern Siberia

    SciTech Connect

    Light, M.; Maslanyj, M.; Davidson, K. )

    1993-09-01

    Recently acquired seismic, well, and regional geological data imply favorable conditions for the accumulation of oil and gas in the 20,000 km[sup 2] Sredne-Amursky basin. Major graben and northeast-trending sinistral wrench-fault systems are recognized in the basin. Lower and Upper Cretaceous sediments are up to 9000 and 3000 m thick, respectively. Paleogeographic reconstructions imply that during the Late Triassic-Early Cretaceous the Sredne-Amursky basin was part of a narrow marine embayment (back-arc basin), which was open to the north. During the Cretaceous, the region was part of a foreland basin complicated by strike-slip, which produced subsidence related to transtension during oblique collision of the Sikhote-Alin arc with Eurasian margin. Contemporaneous uplift also related to this collision migrated from south to north and may have sourced northward-directed deltas and alluvial fans, which fed northward into the closing back-arc basin between 130 and 85 Ma. The progradational clastic succession of the Berriasian-Albian and the Late Cretaceous fluvial, brackish water and paralic sediments within the basin may be analogous to the highly productive late Tertiary clastics of the Amur River delta in the northeast Sakhalin basin. Cretaceous-Tertiary lacustrine-deltaic sapropelic shales provide significant source and seal potential and potential reservoirs occur in the Cretaceous and Tertiary. Structural plays were developed during Cretaceous rifting and subsequent strike-slip deformation. If the full hydrocarbon potential of the Sredne-Amursky basin is to be realized, the regional appraisal suggests that exploration should be focused toward the identification of plays related to prograding Cretaceous deltaic depositional systems.

  6. River mobility in a permafrost dominated floodplain

    NASA Astrophysics Data System (ADS)

    Rowland, J.; Wilson, C.; Brumby, S.; Pope, P.

    2009-04-01

    Along arctic coastlines, recent studies have attributed dramatic increases in the rates of shoreline erosion to global climate change and permafrost degradation. While across much of the arctic, changes in the size and number of lakes have been interpreted as the result of permafrost degradation altering surface water dynamics. The potential influence of climate change and permafrost thawing on the mobility and form of arctic rivers, however, has been relatively unexplored to date. In rivers located within permafrost, some to potentially most, of the cohesive bank strength may be derived from frozen materials. It is likely that, as permafrost thaws, river bank erosion may increase, in turn influencing both migration rates and channel planform. Using automated feature extraction software (GeniePro), we quantified the of the mobility of a 200 km reach of the Yukon River through the Yukon Flats region located just north of Fairbanks, Alaska, USA. The Yukon Flats is an area of comprised of both continuous and discontinuous permafrost. Based on both changes in lake distributions and wintertime river base flows, it has been suggested that permafrost in this area has been experiencing recent thawing. In this reach, the Yukon River transitions from a 2 km wide braided channel to a multi-thread meandering channel where individual threads are approximately 1 km wide and the floodplain preserves prior meander cutoffs and oxbow lakes. Preliminary results from thirty years of LANDSAT imagery shows a surprising stability of channel location (at the image resolution of 30m/pixel) given the channel form. Within the braid-belt there is localized relocation of channel threads and mid-channel islands, though along much of the reach, the change in the location of channels banks is close to the resolution of the imagery. At the most active bends, bank migration rates range from 0.007 to 0.02 channel widths per year. These rates are comparable to system wide average rates observed on

  7. Including independent estimates and uncertainty to quantify total abundance of fish migrating in a large river system: walleye (Sander vitreus) in the Maumee River, Ohio

    USGS Publications Warehouse

    Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Kocovsky, Patrick M.; Tyson, Jeffrey T.; Weimer, Eric J.; Vandergoot, Christopher S.

    2013-01-01

    Walleye (Sander vitreus) in Lake Erie is a valuable and migratory species that spawns in tributaries. We used hydroacoustic sampling, gill net sampling, and Bayesian state-space modeling to estimate the spawning stock abundance, characterize size and sex structure, and explore environmental factors cuing migration of walleye in the Maumee River for 2011 and 2012. We estimated the spawning stock abundance to be between 431,000 and 1,446,000 individuals in 2011 and between 386,400 and 857,200 individuals in 2012 (95% Bayesian credible intervals). A back-calculation from a concurrent larval fish study produced an estimate of 78,000 to 237,000 spawners for 2011. The sex ratio was skewed towards males early in the spawning season but approached 1:1 later, and larger individuals entered the river earlier in the season than smaller individuals. Walleye migration was greater during low river discharge and intermediate temperatures. Our approach to estimating absolute abundance and uncertainty as well as characterization of the spawning stock could improve assessment and management of this species, and our methodology is applicable to other diadromous populations.

  8. Lateral Turbulence Intensity and Plume Meandering During Stable Conditions.

    NASA Astrophysics Data System (ADS)

    Hanna, Steven R.

    1983-08-01

    There is much evidence in the literature for the presence of mesoscale lateral meanders in the stable nighttime boundary layer. These meanders result in relatively high lateral turbulence intensities and diffusion rates when averaged over an hour. Anemometer data from 17 overnight experiments at Cinder Cone Butte in Idaho are analyzed to show that the dominant period of the mesoscale meanders is about two hours. Lidar cross-sections of tracer plumes from these same experiments show that the hourly average y is often dominated by meandering. Since meandering is not always observed for given meteorological conditions, it is suggested that nighttime diffusion cannot be accurately predicted without using onsite observations of wind fluctuations. In case no turbulence data are available, an empirical formula is suggested that predicts the hourly average lateral turbulence intensity as a function of wind speed and hour-to-hour variation in wind direction.

  9. Streamwise vortex meander in a plane mixing layer

    NASA Technical Reports Server (NTRS)

    Leboeuf, Richard L.; Mehta, Rabindra D.

    1993-01-01

    The present experimental study was conducted in order to determine the existence of streamwise vortex meander in a mixing layer, and if present, its significance on the measured properties. The dependence of the velocity cross-correlation on the fixed probe location was shown to be a good indicator of the stationarity of the streamwise vortex location. The cross-correlation measurements obtained here indicate that spanwise meander is negligible, although transverse apparent meander (normal to the plane of the mixing layer) was indicated. The transverse meander, exemplified by the elliptical shape of the mean streamwise vorticity contours, was expected, since the streamwise vorticity in the braid region is essentially inclined, with respect to the streamwise direction. These conclusions were supported by results of estimated spanwise profiles of the transverse velocity component. The balance of evidence suggests that the measured mean streamwise vorticity decay is representative of the decay of the vorticity rather than an artifact of meander.

  10. Hydrodynamics and sediment transport in a meandering channel with a model axial-flow hydrokinetic turbine

    NASA Astrophysics Data System (ADS)

    Hill, Craig; Kozarek, Jessica; Sotiropoulos, Fotis; Guala, Michele

    2016-02-01

    An investigation into the interactions between a model axial-flow hydrokinetic turbine (rotor diameter, dT = 0.15 m) and the complex hydrodynamics and sediment transport processes within a meandering channel was carried out in the Outdoor StreamLab research facility at the University of Minnesota St. Anthony Falls Laboratory. This field-scale meandering stream with bulk flow and sediment discharge control provided a location for high spatiotemporally resolved measurements of bed and water surface elevations around the model turbine. The device was installed within an asymmetric, erodible channel cross section under migrating bed form and fixed outer bank conditions. A comparative analysis between velocity and topographic measurements, with and without the turbine installed, highlights the local and nonlocal features of the turbine-induced scour and deposition patterns. In particular, it shows how the cross-section geometry changes, how the bed form characteristics are altered, and how the mean flow field is distorted both upstream and downstream of the turbine. We further compare and discuss how current energy conversion deployments in meander regions would result in different interactions between the turbine operation and the local and nonlocal bathymetry compared to straight channels.

  11. Genetics, recruitment, and migration patterns of Arctic Cisco (Coregonus autumnalis) in the Colville River, Alaska and Mackenzie River, Canada

    USGS Publications Warehouse

    Zimmerman, Christian E.; Ramey, Andy M.; Turner, S.; Mueter, Franz J.; Murphy, S.; Nielsen, Jennifer L.

    2013-01-01

    Arctic cisco Coregonus autumnalis have a complex anadromous life history, many aspects of which remain poorly understood. Some life history traits of Arctic cisco from the Colville River, Alaska, and Mackenzie River basin, Canada, were investigated using molecular genetics, harvest data, and otolith microchemistry. The Mackenzie hypothesis, which suggests that Arctic cisco found in Alaskan waters originate from the Mackenzie River system, was tested using 11 microsatellite loci and a single mitochondrial DNA gene. No genetic differentiation was found among sample collections from the Colville River and the Mackenzie River system using molecular markers (P > 0.19 in all comparisons). Model-based clustering methods also supported genetic admixture between sample collections from the Colville River and Mackenzie River basin. A reanalysis of recruitment patterns to Alaska, which included data from recent warm periods and suspected changes in atmospheric circulation patterns, still finds that recruitment is correlated to wind conditions. Otolith microchemistry (Sr/Ca ratios) confirmed repeated, annual movements of Arctic cisco between low-salinity habitats in winter and marine waters in summer.

  12. The effects of river impoundment and hatchery rearing on the migration behavior of juvenile steelhead in the Lower Snake River, Washington

    USGS Publications Warehouse

    Plumb, J.M.; Perry, R.W.; Adams, N.S.; Rondorf, D.W.

    2006-01-01

    We used radiotelemetry to monitor the migration behavior of juvenile hatchery and wild steelhead Oncorhynchus mykiss as they migrated through Lower Granite Reservoir and Dam on the lower Snake River, Washington. From 1996 to 2001, we surgically implanted radio transmitters in 1,540 hatchery steelhead and 1,346 wild steelhead. For analysis, we used the inverse Gaussian distribution to describe travel time distributions for cohorts (>50 fish) of juvenile steelhead as they migrated downriver. Mean travel rates were significantly related to reach- and discharge-specific water velocities. Also, mean travel rates near the dam were slower for a given range of water velocities than were mean travel rates through the reservoir, indicating that the presence of the dam caused delay to juvenile steelhead over and above the effect of water velocity. Hatchery steelhead took about twice as long as wild steelhead to pass the dam as a result of the higher proportions of hatchery steelhead traveling upriver from the dam. Because upriver travel and the resulting migration delay might decrease survival, it is possible that hatchery steelhead survive at lower rates than wild steelhead. Our analysis identified a discharge threshold (???2,400 m3/s) below which travel time and the percentage of fish traveling upriver from the dam increased rapidly, providing support for the use of minimum flow targets to mitigate for fish delay and possibly enhance juvenile steelhead survival.

  13. Comparative ontogenetic behavior and migration of kaluga, Huso dauricus, and Amur sturgeon, Acipenser schrenckii, from the Amur River

    USGS Publications Warehouse

    Zhuang, P.; Kynard, B.; Zhang, L.; Zhang, T.; Cao, W.

    2003-01-01

    We conducted laboratory experiments with kaluga, Huso dauricus, and Amur sturgeon, Acipenser schrenckii, to develop a conceptual model of early behavior. We daily observed embryos (first life phase after hatching) and larvae (period initiating exogenous feeding) to day-30 (late larvae) for preference of bright habitat and cover, swimming distance above the bottom, up- and downstream movement, and diel activity. Day-0 embryos of both species strongly preferred bright, open habitat and initiated a strong, downstream migration that lasted 4 days (3 day peak) for kaluga and 3 days (2 day peak) for Amur sturgeon. Kaluga migrants swam far above the bottom (150 cm) on only 1 day and moved day and night; Amur sturgeon migrants swam far above the bottom (median 130 cm) during 3 days and were more nocturnal than kaluga. Post-migrant embryos of both species moved day and night, but Amur sturgeon used dark, cover habitat and swam closer to the bottom than kaluga. The larva period of both species began on day 7 (cumulative temperature degree-days, 192.0 for kaluga and 171.5 for Amur sturgeon). Larvae of both species preferred open habitat. Kaluga larvae strongly preferred bright habitat, initially swam far above the bottom (median 50-105 cm), and migrated downstream at night during days 10-16 (7-day migration). Amur sturgeon larvae strongly avoided illumination, had a mixed response to white substrate, swam 20-30 cm above the bottom during most days, and during days 12-34 (most of the larva period) moved downstream mostly at night (23-day migration). The embryo-larva migration style of the two species likely shows convergence of non-related species for a common style in response to environmental selection in the Amur River. The embryo-larva migration style of Amur sturgeon is unique among Acipenser yet studied.

  14. Meandering worms: mechanics of undulatory burrowing in muds

    PubMed Central

    Dorgan, Kelly M.; Law, Chris J.; Rouse, Greg W.

    2013-01-01

    Recent work has shown that muddy sediments are elastic solids through which animals extend burrows by fracture, whereas non-cohesive granular sands fluidize around some burrowers. These different mechanical responses are reflected in the morphologies and behaviours of their respective inhabitants. However, Armandia brevis, a mud-burrowing opheliid polychaete, lacks an expansible anterior consistent with fracturing mud, and instead uses undulatory movements similar to those of sandfish lizards that fluidize desert sands. Here, we show that A. brevis neither fractures nor fluidizes sediments, but instead uses a third mechanism, plastically rearranging sediment grains to create a burrow. The curvature of the undulating body fits meander geometry used to describe rivers, and changes in curvature driven by muscle contraction are similar for swimming and burrowing worms, indicating that the same gait is used in both sediments and water. Large calculated friction forces for undulatory burrowers suggest that sediment mechanics affect undulatory and peristaltic burrowers differently; undulatory burrowing may be more effective for small worms that live in sediments not compacted or cohesive enough to extend burrows by fracture. PMID:23446526

  15. The Owens River as a tiltmeter for Long Valley caldera, California

    SciTech Connect

    Reid, J.B. Jr )

    1992-05-01

    In the lower 11 km of its course around the resurgent dome of Long Valley caldera, the Owens River displays two parallel meander belts, comparable in meander wavelength and amplitude but unequal in age, elevation, and discharge. It appears the two belts take turns carrying the river's flow depending on whether the dome is inflating or subsiding. The inboard belt, some 200-300 m closer to the dome and now 30-60 cm higher in elevation, contains an underfit stream and is now being abandoned. The outboard channel formed in a series of avulsions apparently induced by recent uplift of the dome. In the upper 4 km of the two-channel reach, avulsion occurred between 1856 and 1878 as inferred from the original US Coast and Geodetic Survey mapping the caldera. Avulsion had already occurred by 1856 in the lower 4 km of the river, suggesting a possible migration of the center of uplift through time. More ancient meander scars at the inboard and outboard limits of the floodplain imply additional earlier episodes of inflation and subsidence. Projection of surveyed topographic profiles across the river's floodplain to the center of the dome suggests that cumulative recent uplift is on the order of 15-35 m, or about 30-70 times greater than that measured for the caldera since 1979 (Castle et al. 1984). The duration of the era of subsidence can be estimated by comparing oxbow densities in the old and new meander belts in the upper two-channel reach; the data suggest that the dome may have been in subsidence for a period of at least 500 to 1,000 yr ending about 150 yr ago. No eruptions of the Long Valley volcanic system have accompanied these inflations and subsidings.

  16. Water velocity, turbulence, and migration rate of subyearling fall Chinook salmon in the free-flowing and impounded Snake River

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Kock, Tobias J.; Haskell, Craig A.; Connor, William P.; Steinhorst, R. Kirk

    2009-01-01

    We studied the migratory behavior of subyearling fall Chinook salmon Oncorhynchus tshawytscha in free-flowing and impounded reaches of the Snake River to evaluate the hypothesis that velocity and turbulence are the primary causal mechanisms of downstream migration. The hypothesis states that impoundment reduces velocity and turbulence and alters the migratory behavior of juvenile Chinook salmon as a result of their reduced perception of these cues. At a constant flow (m3 /s), both velocity (km/d) and turbulence (the SD of velocity) decreased from riverine to impounded habitat as cross-sectional areas increased. We found evidence for the hypothesis that subyearling Chinook salmon perceive velocity and turbulence cues and respond to these cues by varying their behavior. The percentage of the subyearlings that moved faster than the average current speed decreased as fish made the transition from riverine reaches with high velocities and turbulence to upper reservoir reaches with low velocities and turbulence but increased to riverine levels again as the fish moved further down in the reservoir, where velocity and turbulence remained low. The migration rate (km/d) decreased in accordance with longitudinal reductions in velocity and turbulence, as predicted by the hypothesis. The variation in migration rate was better explained by a repeatedmeasures regression model containing velocity (Akaike’s information criterion ¼ 1,769.0) than a model containing flow (2,232.6). We conclude that subyearling fall Chinook salmon respond to changes in water velocity and turbulence, which work together to affect the migration rate.

  17. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 2000-2001 Annual Report.

    SciTech Connect

    Achord, Stephen; Axel, Gordon A.; Hockersmith, Eric E.

    2002-07-01

    This report details the 2001 results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends in the cumulative data collected for this project from Oregon and Idaho streams since 1989. The project was initiated after detection data from passive-integrated-transponder tags (PIT tags) had shown distinct differences in migration patterns between wild and hatchery fish for three consecutive years. National Marine Fisheries Service (NMFS) investigators first observed these data in 1989. The data originated from tagging and interrogation operations begun in 1988 to evaluate smolt transportation for the U.S. Army Corps of Engineers.

  18. Migration depths of adult steelhead Oncorhynchus mykiss in relation to dissolved gas supersaturation in a regulated river system

    SciTech Connect

    Johnson, Eric L.; Clabough, Tami S.; Caudill, Christopher C.; keefer, matthew L.; Peery, Christopher A.; Richmond, Marshall C.

    2010-04-01

    Adult steelhead tagged with archival transmitters primarily migrated through a large river corridor at depths > 2 m, interspersed with frequent but short (< 5 min) periods closer to the surface. The recorded swimming depths and behaviours probably provided adequate hydrostatic compensation for the encountered supersaturated dissolved gas conditions and probably limited development of gas bubble disease (GBD). Results parallel those from a concurrent adult Chinook salmon study, except steelhead experienced greater seasonal variability and were more likely to have depth-uncompensated supersaturation exposure in some dam tailraces, perhaps explaining the higher incidence of GBD in this species.

  19. Migration depths of juvenile Chinook salmon and steelhead relative to total dissolved gas supersaturation in a Columbia River reservoir

    USGS Publications Warehouse

    Beeman, J.W.; Maule, A.G.

    2006-01-01

    The in situ depths of juvenile salmonids Oncorhynchus spp. were studied to determine whether hydrostatic compensation was sufficient to protect them from gas bubble disease (GBD) during exposure to total dissolved gas (TDG) supersaturation from a regional program of spill at dams meant to improve salmonid passage survival. Yearling Chinook salmon O. tshawytscha and juvenile steelhead O. mykiss implanted with pressure-sensing radio transmitters were monitored from boats while they were migrating between the tailrace of Ice Harbor Dam on the Snake River and the forebay of McNary Dam on the Columbia River during 1997-1999. The TDG generally decreased with distance from the tailrace of the dam and was within levels known to cause GBD signs and mortality in laboratory bioassays. Results of repeated-measures analysis of variance indicated that the mean depths of juvenile steelhead were similar throughout the study area, ranging from 2.0 m in the Snake River to 2.3 m near the McNary Dam forebay. The mean depths of yearling Chinook salmon generally increased with distance from Ice Harbor Dam, ranging from 1.5 m in the Snake River to 3.2 m near the forebay. Juvenile steelhead were deeper at night than during the day, and yearling Chinook salmon were deeper during the day than at night. The TDG level was a significant covariate in models of the migration depth and rates of each species, but no effect of fish size was detected. Hydrostatic compensation, along with short exposure times in the area of greatest TDG, reduced the effects of TDG exposure below those generally shown to elicit GBD signs or mortality. Based on these factors, our results indicate that the TDG limits of the regional spill program were safe for these juvenile salmonids.

  20. Movements of adult chinook salmon during spawning migration in a metals-contaminated system, Coeur d'Alene River, Idaho

    USGS Publications Warehouse

    Goldstein, J.N.; Woodward, D.F.; Farag, A.M.

    1999-01-01

    Spawning migration of adult male chinook salmon Oncorhynchus tshawytscha was monitored by radio telemetry to determine their response to the presence of metals contamination in the South Fork of the Coeur d'Alene River, Idaho. The North Fork of the Coeur d'Alene River is relatively free of metals contamination and was used as a control. In all, 45 Chinook salmon were transported from their natal stream. Wolf Lodge Creek, tagged with radio transmitters, and released in the Coeur d'Alene River 2 km downstream of the confluence of the South Fork and the North Fork of the Coeur d'Alene River. Fixed telemetry receivers were used to monitor the upstream movement of the tagged chinook salmon through the confluence area for 3 weeks after release. During this period, general water quality and metals concentrations were monitored in the study area. Of the 23 chinook salmon observed to move upstream from the release site and through the confluence area, the majority (16 fish, 70%) moved up the North Fork, and only 7 fish (30%) moved up the South Fork, where greater metals concentrations were observed. Our results agree with laboratory findings and suggest that natural fish populations will avoid tributaries with high metals contamination.

  1. The Fate of Oxbow Lakes Determined by Mechanisms of Meander Cutoff

    NASA Astrophysics Data System (ADS)

    Constantine, José; Dieras, Pauline; Hales, Tristram; Piégay, Hervé

    2016-04-01

    Oxbow lakes are some of the most widespread and distinctive landforms along meandering rivers, but their persistence as aquatic habitat may depend on the mechanisms of their formation. Based on an archive of historical aerial photographs and maps of seven meandering rivers, we use changes in water-surface area as a proxy for alluviation to demonstrate that oxbows and abandoned channels created by neck cutoff can persist in the floodplain for centuries, whereas the oxbows and abandoned channels created by chute cutoff appear to undergo rapid alluviation following their formation. Differences in the persistence of the thirty-seven oxbows and abandoned channels under study are due to differences in the planform characteristics that are associated with each cutoff mechanism. Using theoretical and empirical relations that describe the conditions required for the conveyance of riverbed sediment, we show that neck cutoff results in the successful transition of persistent oxbows because they lack the planform characteristics required for sustaining the flows needed to prevent plug formation. The angle by which flow is diverted and the magnitude by which the river is locally steepened is significantly greater for channels created by neck cutoff than for those created by chute cutoff.

  2. Remote sensing-based analysis of the planform changes in the Upper Amazon River over the period 1986-2006

    NASA Astrophysics Data System (ADS)

    Rozo, Max G.; Nogueira, Afonso C. R.; Castro, Carlomagno Soto

    2014-04-01

    An analysis of the planform changes of the Colombian reach of the Amazon River was carried out over a period of 19.9 years. Remote sensing image processing techniques were applied to Landsat images acquired in 1986, 1994, 2001 and, 2006. These images were selected based on minimal daily water level variations, while providing the widest temporal span. Plan view river changes and geomorphologic characteristics were examined to identify which channel pattern classification best represents this large tropical river system. Discharge was also analyzed to determine whether changes in the river's plan view are a direct response to variations in discharge. The system had a depositional tendency between 1986 and 2006, with a period where erosion was more intense than deposition between 1994 and 2001. Percent change in the plan view area of the system (1.4% yr-1) and the maximum migration rates (125 m yr-1) suggest that this reach of the Amazon is less active than reaches upstream and the downstream reach between the confluences of the Jutaí and Japurá Rivers. Variations in discharge appear to be responsible for deposition and erosion dynamics observed after this remote sensing analysis in the Colombian reach of the Amazon River. Characteristics including multiple channels with vegetated islands developed from within-channel deposition, meandering planform, lateral activity of channel margins, and the absence of islands with saucer-like morphology suggest a multichannel, meandering pattern for this reach of the Amazon, that corresponds to a laterally active anabranching river.

  3. Freedom Space for Rivers: A Sustainable Management Approach to Enhance River Resilience

    NASA Astrophysics Data System (ADS)

    Biron, Pascale M.; Buffin-Bélanger, Thomas; Larocque, Marie; Choné, Guénolé; Cloutier, Claude-André; Ouellet, Marie-Audray; Demers, Sylvio; Olsen, Taylor; Desjarlais, Claude; Eyquem, Joanna

    2014-11-01

    River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contrasted rivers in Quebec (Canada). Mobility and flooding spaces are determined for the three rivers, and three levels of "freedom space" are subsequently defined based on the combination of the two spaces. The first level of freedom space includes very frequently flooded and highly mobile zones over the next 50 years, as well as riparian wetlands. It provides the minimum space for both fluvial and ecological functionality of the river system. On average for the three studied sites, this minimum space was approximately 1.7 times the channel width, but this minimum space corresponds to a highly variable width which must be determined from a thorough hydrogeomorphic assessment and cannot be predicted using a representative average. The second level includes space for floods of larger magnitude and provides for meanders to migrate freely over a longer time period. The last level of freedom space represents exceptional flood zones. We propose the freedom space concept to be implemented in current river management legislation because it promotes a sustainable way to manage river systems, and it increases their resilience to climate and land use changes in comparison with traditional river management approaches which are based on frequent and spatially restricted interventions.

  4. Freedom space for rivers: a sustainable management approach to enhance river resilience.

    PubMed

    Biron, Pascale M; Buffin-Bélanger, Thomas; Larocque, Marie; Choné, Guénolé; Cloutier, Claude-André; Ouellet, Marie-Audray; Demers, Sylvio; Olsen, Taylor; Desjarlais, Claude; Eyquem, Joanna

    2014-11-01

    River systems are increasingly under stress and pressure from agriculture and urbanization in riparian zones, resulting in frequent engineering interventions such as bank stabilization or flood protection. This study provides guidelines for a more sustainable approach to river management based on hydrogeomorphology concepts applied to three contrasted rivers in Quebec (Canada). Mobility and flooding spaces are determined for the three rivers, and three levels of "freedom space" are subsequently defined based on the combination of the two spaces. The first level of freedom space includes very frequently flooded and highly mobile zones over the next 50 years, as well as riparian wetlands. It provides the minimum space for both fluvial and ecological functionality of the river system. On average for the three studied sites, this minimum space was approximately 1.7 times the channel width, but this minimum space corresponds to a highly variable width which must be determined from a thorough hydrogeomorphic assessment and cannot be predicted using a representative average. The second level includes space for floods of larger magnitude and provides for meanders to migrate freely over a longer time period. The last level of freedom space represents exceptional flood zones. We propose the freedom space concept to be implemented in current river management legislation because it promotes a sustainable way to manage river systems, and it increases their resilience to climate and land use changes in comparison with traditional river management approaches which are based on frequent and spatially restricted interventions.

  5. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 2002-2003 Annual Report.

    SciTech Connect

    Achord, Stephen; McNatt, Regan A.; Hockersmith, Eric E.

    2004-04-01

    Prior to 1992, decisions on dam operations and use of stored water relied on recoveries of branded hatchery fish, index counts at traps and dams, and flow patterns at the dams. The advent of PIT-tag technology provided the opportunity to precisely track the smolt migrations of many wild stocks as they pass through the hydroelectric complex and other monitoring sites on their way to the ocean. With the availability of the PIT tag, a more complete approach to these decisions was undertaken starting in 1992 with the addition of PIT-tag detections of several wild spring and summer chinook salmon stocks at Lower Granite Dam. Using data from these detections, we initiated development of a database on wild fish, addressing several goals of the Columbia River Basin Fish and Wildlife Program of the Pacific Northwest Electric Power Planning Council and Conservation Act (NPPC 1980). Section 304(d) of the program states, ''The monitoring program will provide information on the migrational characteristics of the various stocks of salmon and steelhead within the Columbia Basin.'' Further, Section 201(b) urges conservation of genetic diversity, which will be possible only if wild stocks are preserved. Section 5.9A.1 of the 1994 Fish and Wildlife Program states that field monitoring of smolt movement will be used to determine the best timing for water storage releases and Section 5.8A.8 states that continued research is needed on survival of juvenile wild fish before they reach the first dam with special attention to water quantity, quality, and several other factors. The goals of this ongoing study are as follows (1) Characterize the migration timing and estimate parr-to-smolt survival of different stocks of wild Snake River spring/summer chinook salmon smolts at Lower Granite Dam. (2) Determine whether consistent migration patterns are apparent. (3) Determine what environmental factors influence these patterns. (4) Characterize the migrational behavior and estimate survival of

  6. Observations of Sand Dune Migration on the Colorado River in Grand Canyon using High-Resolution Multibeam Bathymetry

    NASA Astrophysics Data System (ADS)

    Kaplinski, M. A.; Buscmobe, D.; Ashley, T.; Tusso, R.; Grams, P. E.; McElroy, B. J.; Mueller, E. R.; Hamill, D.

    2015-12-01

    Repeat, high-resolution multibeam bathymetric surveys were conducted in March and July 2015 along a reach of the Colorado River in Grand Canyon near the Diamond Creek gage (362 km downstream of Lees Ferry, AZ) to characterize the migration of sand dunes. The surveys were collected as part of a study designed to quantify the relative importance of bedload and suspended sediment transport and develop a predictive relationship for bedload transport. Concurrent measurements of suspended-sediment concentrations, bed-sediment grain size, and water velocity were also collected. The study site is approximately 350 m long and 50 m wide; water depths are 7 to 10 m during normal flows; and a field of sand dunes form along its entire length with negligible coarse material at the bed surface. Full swath coverage of the site required about 6 to 10 minutes to complete with two passes of the survey vessel. Mapping occurred continuously during several survey periods. For each survey period, time-series of bathymetric maps were constructed from each pair of survey lines. In March, surveys were collected over durations of 2, 3, 9, and 11 hours, at discharges of 339 to 382 m3/s. In July, surveys were collected over durations of 4, 4, and 13 hours, at discharges ranging from 481 to 595 ft3/s. These surveys capture the migration of sand dunes over a wide range of discharge with an unprecedented temporal resolution. The dunes in March were between 30 and 50 cm in height, 5 m in length, and migrating downstream at about 1 m per hour. In July, dunes were between 75 and 130 cm in height and 10-15 m in length, and were migrating downstream at rates of 5 to 2 m per hour. The surveys also reveal that the dune migration is spatially and temporally variable, with fast-migrating small dunes variably superimposed on slower-moving larger dunes. The dunes also refract around shoreline talus piles and other flow constrictions collectively causing a large degree of dune deformation as they migrate.

  7. Abundance, Timing of Migration, and Egg-to-Smolt Survival of Juvenile Chum Salmon, Kwethluk River, Alaska, 2007 and 2008

    USGS Publications Warehouse

    Burril, Sean E.; Zimmerman, Christian E.; Finn, James E.; ,; Gillikin, Daniel; ,

    2010-01-01

    To better understand and partition mortality among life stages of chum salmon (Oncorhynchus keta), we used inclined-plane traps to monitor the migration of juveniles in the Kwethluk River, Alaska in 2007 and 2008. The migration of juvenile chum salmon peaked in mid-May and catch rates were greatest when water levels were rising. Movement of chum salmon was diurnal with highest catch rates occurring during the hours of low light (that is, 22:00 to 10:00). Trap efficiency ranged from 0.37 to 4.04 percent (overall efficiency = 1.94 percent). Total abundance of juvenile chum salmon was estimated to be 2.0 million fish in 2007 and 2.9 million fish in 2008. On the basis of the estimate of chum salmon females passing the Kwethluk River weir and age-specific fecundity, we estimated the potential egg deposition (PED) upstream of the weir and trapping site. Egg-to-smolt survival, calculated by dividing the estimate of juvenile chum salmon emigrating past the weir site by the estimate of PED, was 4.6 percent in 2007 and 5.2 percent in 2008. In addition to chum salmon, Chinook salmon O. tshawytscha), coho salmon (O. kisutch), sockeye salmon (O. nerka), and pink salmon (O. gorbuscha), as well as ten other fish species, were captured in the traps. As with chum salmon, catch of these species increased during periods of increasing discharge and peaked during hours of low light. This study successfully determined the characteristics of juvenile salmon migrations and estimated egg-to-smolt survival for chum salmon. This is the first estimate of survival for any juvenile salmon in the Arctic-Yukon-Kuskokwim region of Alaska and demonstrates an approach that can help to partition mortality between freshwater and marine life stages, information critical to understanding the dynamics of salmon in this region.

  8. Simulating the Effects of Sea Level Rise on the Resilience and Migration of Tidal Wetlands along the Hudson River.

    PubMed

    Tabak, Nava M; Laba, Magdeline; Spector, Sacha

    2016-01-01

    Sea Level Rise (SLR) caused by climate change is impacting coastal wetlands around the globe. Due to their distinctive biophysical characteristics and unique plant communities, freshwater tidal wetlands are expected to exhibit a different response to SLR as compared with the better studied salt marshes. In this study we employed the Sea Level Affecting Marshes Model (SLAMM), which simulates regional- or local-scale changes in tidal wetland habitats in response to SLR, and adapted it for application in a freshwater-dominated tidal river system, the Hudson River Estuary. Using regionally-specific estimated ranges of SLR and accretion rates, we produced simulations for a spectrum of possible future wetland distributions and quantified the projected wetland resilience, migration or loss in the HRE through the end of the 21st century. Projections of total wetland extent and migration were more strongly determined by the rate of SLR than the rate of accretion. Surprisingly, an increase in net tidal wetland area was projected under all scenarios, with newly-formed tidal wetlands expected to comprise at least 33% of the HRE's wetland area by year 2100. Model simulations with high rates of SLR and/or low rates of accretion resulted in broad shifts in wetland composition with widespread conversion of high marsh habitat to low marsh, tidal flat or permanent inundation. Wetland expansion and resilience were not equally distributed through the estuary, with just three of 48 primary wetland areas encompassing >50% of projected new wetland by the year 2100. Our results open an avenue for improving predictive models of the response of freshwater tidal wetlands to sea level rise, and broadly inform the planning of conservation measures of this critical resource in the Hudson River Estuary.

  9. Simulating the Effects of Sea Level Rise on the Resilience and Migration of Tidal Wetlands along the Hudson River

    PubMed Central

    Tabak, Nava M.; Laba, Magdeline; Spector, Sacha

    2016-01-01

    Sea Level Rise (SLR) caused by climate change is impacting coastal wetlands around the globe. Due to their distinctive biophysical characteristics and unique plant communities, freshwater tidal wetlands are expected to exhibit a different response to SLR as compared with the better studied salt marshes. In this study we employed the Sea Level Affecting Marshes Model (SLAMM), which simulates regional- or local-scale changes in tidal wetland habitats in response to SLR, and adapted it for application in a freshwater-dominated tidal river system, the Hudson River Estuary. Using regionally-specific estimated ranges of SLR and accretion rates, we produced simulations for a spectrum of possible future wetland distributions and quantified the projected wetland resilience, migration or loss in the HRE through the end of the 21st century. Projections of total wetland extent and migration were more strongly determined by the rate of SLR than the rate of accretion. Surprisingly, an increase in net tidal wetland area was projected under all scenarios, with newly-formed tidal wetlands expected to comprise at least 33% of the HRE’s wetland area by year 2100. Model simulations with high rates of SLR and/or low rates of accretion resulted in broad shifts in wetland composition with widespread conversion of high marsh habitat to low marsh, tidal flat or permanent inundation. Wetland expansion and resilience were not equally distributed through the estuary, with just three of 48 primary wetland areas encompassing >50% of projected new wetland by the year 2100. Our results open an avenue for improving predictive models of the response of freshwater tidal wetlands to sea level rise, and broadly inform the planning of conservation measures of this critical resource in the Hudson River Estuary. PMID:27043136

  10. Richness and diversity of helminth communities in the Japanese grenadier anchovy, Coilia nasus, during its anadromous migration in the Yangtze River, China.

    PubMed

    Li, Wen X; Zou, Hong; Wu, Shan G; Song, Rui; Wang, Gui T

    2012-06-01

    To determine the relationship between the species richness, diversity of helminth communities, and migration distance during upward migration from coast to freshwater, helminth communities in the anadromous fish Coilia nasus were investigated along the coast of the East China Sea, the Yangtze Estuary, and 3 localities on the Yangtze River. Six helminth species were found in 224 C. nasus . Changes in salinity usually reduced the survival time of parasites, and thus the number of helminth species and their abundance. Except for the 2 dominant helminths, the acanthocephalan Acanthosentis cheni and the nematode Contracaecum sp., mean abundance of other 4 species of helminths was rather low (<1.0) during the upward migration in the Yangtze River. Mean abundance of the 2 dominant helminths peaked in the Yangtze Estuary and showed no obvious decrease among the 3 localities on the Yangtze River. Mean species richness, Brillouin's index, and Shannon index were also highest in the estuary (1.93 ± 0.88, 0.28 ± 0.25, and 0.37 ± 0.34, respectively) and did not exhibit marked decline at the 3 localities on the Yangtze River. A significant negative correlation was not seen between the similarity and the geographical distance (R  =  -0.5104, P  =  0.1317). The strong salinity tolerance of intestinal helminths, relatively brief stay in the Yangtze River, and large amount of feeding on small fish and shrimp when commencing spawning migration perhaps were responsible for the results.

  11. Migration of the Pee Dee River system inferred from ancestral paleochannels underlying the South Carolina Grand Strand and Long Bay inner shelf

    USGS Publications Warehouse

    Baldwin, W.E.; Morton, R.A.; Putney, T.R.; Katuna, M.P.; Harris, M.S.; Gayes, P.T.; Driscoll, N.W.; Denny, J.F.; Schwab, W.C.

    2006-01-01

    Several generations of the ancestral Pee Dee River system have been mapped beneath the South Carolina Grand Strand coastline and adjacent Long Bay inner shelf. Deep boreholes onshore and high-resolution seismic-reflection data offshore allow for reconstruction of these paleochannels, which formed during glacial lowstands, when the Pee Dee River system incised subaerially exposed coastal-plain and continental-shelf strata. Paleochannel groups, representing different generations of the system, decrease in age to the southwest, where the modern Pee Dee River merges with several coastal-plain tributaries at Winyah Bay, the southern terminus of Long Bay. Positions of the successive generational groups record a regional, southwestward migration of the river system that may have initiated during the late Pliocene. The migration was primarily driven by barrier-island deposition, resulting from the interaction of fluvial and shoreline processes during eustatic highstands. Structurally driven, subsurface paleotopography associated with the Mid-Carolina Platform High has also indirectly assisted in forcing this migration. These results provide a better understanding of the evolution of the region and help explain the lack of mobile sediment on the Long Bay inner shelf. Migration of the river system caused a profound change in sediment supply during the late Pleistocene. The abundant fluvial source that once fed sand-rich barrier islands was cut off and replaced with a limited source, supplied by erosion and reworking of former coastal deposits exposed at the shore and on the inner shelf.

  12. Flow structure in submarine meandering channels, a continuous discussion on secondary flow

    NASA Astrophysics Data System (ADS)

    Abad, J. D.; Parker, G.; Sequeiros, O.; Spinewine, B.; Garcia, M. H.; Pirmez, C.

    2011-12-01

    The understanding of the flow structure in deep-sea turbidity currents is important for the formation of submarine meandering channels. Similarly to the case of subaerial channels, several types of secondary flows include turbulence-, curvature- and bed morphodynamic-driven flow structures that modulate sediment transport and channel bed morphodynamics. This study focuses on [1] a review of long-time research effort (Abad et al., 2011) that tackles the description of the secondary flow associated with a subaqueous bottom current (saline) in a high-curvature meandering channel and [2] ongoing numerical simulations of similar settings as the experiments to describe the entire flow structure. In the case of subaerial channels, the classical Rozovskiian paradigm is often invoked which indicates that the near-bottom secondary flow in a bend is directed inward. It has recently been suggested based on experimental and theoretical considerations, however, that this pattern is reversed (near-bottom secondary flow is directed outward) in the case of submarine meandering channels. Experimental results presented here, on the other hand, indicate near-bottom secondary flows that have the same direction as observed in a river (normal secondary flow). The implication is an apparent contradiction between experimental results. This study combines theory, experiments, reconstructions of field flows and ongoing simulations to resolve this apparent contradiction based on the flow densimetric Froude number. Three ranges of densimetric Froude number are found, such that a) in an upper regime, secondary flow is reversed, b) in a middle regime, it is normal and c) in a lower regime, it is reversed. These results are applied to field scale channel-forming turbidity currents in the Amazon submarine canyon-fan system (Amazon Channel) and the Monterey canyon and a saline underflow in the Black Sea flowing from the Bosphorus. Our analysis indicates that secondary flow should be normal

  13. Investigating historical changes in morphodynamic processes associated with channelization of a large Alpine river: the Etsch/Adige River, NE Italy

    NASA Astrophysics Data System (ADS)

    Zen, Simone; Scorpio, Vittoria; Mastronunzio, Marco; Proto, Matteo; Zolezzi, Guido; Bertoldi, Walter; Comiti, Francesco; Surian, Nicola; Prà, Elena Dai

    2016-04-01

    River channel management within the last centuries has largely modified fluvial processes and morphodynamic evolution of most large European rivers. Several river systems experienced extensive channelization early in the 19th century, thus strongly challenging our present ability to detect their morphodynamic functioning with contemporary photogrammetry or cartographical sources. This consequently leaves open questions about their potential future response, especially to management strategies that "give more room" to the river, aiming at partially rehabilitating their natural functioning. The Adige River (Etsch in German), the second longest Italian river, is an exemplary case where channelization occurred more than 150 years ago, and is the focus of the present work. This work aims (i) to explore changes in fundamental morphodynamic processes associated with massive channelization of the Adige River and (ii) to quantify the alteration in river bars characteristics, by using morphodynamic models of bars and meandering. To fulfil our aims we combine the analysis of historical data with morphodynamic mathematical modelling. Historical sources (recovered in a number of European archives), such as hydrotopographical maps, airborne photogrammetry and hydrological datasets were collected to investigate channel morphology before and after the channelization. Information extracted from this analysis was combined with morphodynamic linear models of free migrating and forced steady bars, to investigate river bars and bend stability properties under different hydromorphological scenarios. Moreover, a morphodynamic model for meandering channel was applied to investigate the influence of river channel planform on the evolution of the fluvial bars. Results from the application of morphodynamic models allowed to predict the type, position and geometry of bars characterizing the channelized configuration of the river, and to explain the presently observed relative paucity of bars

  14. Survival and migration route probabilities of juvenile Chinook salmon in the Sacramento-San Joaquin River Delta during the winter of 2009-10

    USGS Publications Warehouse

    Perry, Russell W.; Romine, Jason G.; Brewer, Scott J.; LaCivita, Peter E.; Brostoff, William N.; Chapman, Eric D.

    2012-01-01

    Juvenile Chinook salmon (Oncorhynchus tshawytscha) emigrating from natal tributaries of the Sacramento River may use a number of migration routes to negotiate the Sacramento-San Joaquin River Delta (hereafter, "the Delta"), each of which may influence their probability of surviving. We applied a mark-recapture model to data from acoustically tagged juvenile late-fall Chinook salmon that migrated through the Delta during the winter of 2009-10 (hereafter, 2010). This report presents findings from our fourth year of research. We estimated route-specific survival for four release groups: two release groups that migrated through the Delta in December 2009 and January 2010, and two release groups that migrated during February 2010. Population-level survival through the Delta (SDelta) ranged from 0.374 (SE = 0.040) to 0.524 (SE = 0.034) among releases. Although river flows for the February release groups were substantially higher (20,000-40,000 ft3/s at Freeport) than for the December release groups (about 10,000 ft3/s), SDelta did not differ considerably between release groups. Among migration routes, fish migrating through the Sacramento River exhibited the highest survival, and fish entering the interior Delta exhibited the lowest survival. Fish entering Sutter and Steamboat Sloughs had lower survival than fish entering the Sacramento River during December, but similar survival during February. These patterns were consistent among release groups, and strikingly similar to patterns observed in previous years. Migration routing varied among release groups partly because of differences in river discharge between releases. For the two December release groups, 26.5 and 28.9 percent of fish entered the interior Delta; for the two February release groups, 10.4 and 17.9 percent of fish entered the interior Delta. Differences in routing probabilities between December and February are partly related to the inverse relationship between flow and the fraction of discharge entering

  15. Smolt Migration Characteristics and Mainstem Snake and Columbia River Detection Rates of PIT-Tagged Grande Ronde and Imnaha River Naturally Produced Spring Chinook Salmon, Annual Reports 1993, 1994, 1995 : Fish Research Project, Oregon.

    SciTech Connect

    Walters, Timothy R.; Carmichael, Richard W.; Keefe, MaryLouise

    1996-04-01

    This reports on the second, third, and fourth years of a multi-year study to assess smolt migration characteristics and cumulative detection rates of naturally produced spring chinook salmon (Oncorhynchus tshawytscha) from Northeast Oregon streams. The goal of this project is to develop an understanding of interpopulational and interannual variation in several early life history parameters of naturally produced spring and summer chinook salmon in the Grande Ronde and Imnaha River subbasins. This project will provide information to assist chinook salmon population recovery efforts. Specific populations included in the study are: (1) Catherine Creek; (2) Upper Grande Ronde River; (3) Lostine River; (4) Imnaha River; (5) Wenaha River; and (6) Minam River. In this document, the authors present findings and activities from research completed in 1993, 1994, and 1995.

  16. Determination of Swimming Speeds and Energetic Demands of Upriver Migrating Fall Chinook Salmon (Oncorhynchus Tshawytscha) in the Klickitat River, Washington.

    SciTech Connect

    Brown, Richard S.; Geist, David R.; Confederated Tribes and Bands of the Yakama Nation, Washington

    2002-08-30

    This report describes a study conducted by Pacific Northwest National Laboratory for the Bonneville Power Administration's Columbia Basin Fish and Wildlife Program during the fall of 2001. The objective was to study the migration and energy use of adult fall chinook salmon (Oncorhynchus tshawytscha) traveling up the Klickitat River to spawn. The salmon were tagged with either surgically implanted electromyogram (EMG) transmitters or gastrically implanted coded transmitters and were monitored with mobile and stationary receivers. Swim speed and aerobic and anaerobic energy use were determined for the fish as they attempted passage of three waterfalls on the lower Klickitat River and as they traversed free-flowing stretches between, below, and above the falls. Of the 35 EMG-tagged fish released near the mouth of the Klickitat River, 40% passed the first falls, 24% passed the second falls, and 20% made it to Lyle Falls. None of the EMG-tagged fish were able to pass Lyle Falls, either over the falls or via a fishway at Lyle Falls. Mean swimming speeds ranged from as low as 52.6 centimeters per second (cm s{sup -1}) between falls to as high as 189 (cm s{sup -1}) at falls passage. Fish swam above critical swimming speeds while passing the falls more often than while swimming between the falls (58.9% versus 1.7% of the transmitter signals). However, fish expended more energy swimming the stretches between the falls than during actual falls passage (100.7 to 128.2 kilocalories [kcals] to traverse areas between or below falls versus 0.3 to 1.0 kcals to pass falls). Relationships between sex, length, and time of day on the success of falls passage were also examined. Average swimming speeds were highest during the day in all areas except at some waterfalls. There was no apparent relationship between either fish condition or length and successful passage of waterfalls in the lower Klickitat River. Female fall chinook salmon, however, had a much lower likelihood of passing

  17. [Migration of main odorous compounds in a water supply system with Huangpu River as raw water in Shanghai].

    PubMed

    Bai, Xiao-Hui; Zhang, Ming-De; Jia, Cheng-Shen

    2011-01-01

    Migration and variation of odorous compounds as geosmin, 2-methylisoborneol (MIB) and residual chlorine in drinking water taken from Huangpu River were studied by using headspace solid phase microextraction procedure (HSPME) and gas chromatograph with mass spectrometry. The results showed that, raw water, processed water, pipe water (taken from pump station) and secondary-supply water all contained MIB and geosmin ranging from 2 ng/L to 18 ng/L and 2.68 ng/L to 5.06 ng/L respectively and decreased dramatically during the water processing and distribution system. MIB is proved to be a kind of the odorous compounds in drinking water of Shanghai by comparing the concentrations of MIB and GSM with their odor threshold. The concentration of residual chlorine declined greatly in the distribution system, but because of the high value at the outlet of waterworks, it still may exceeded the influence of MIB and cause the odour problems.

  18. Molecular detection of Campylobacter spp. and fecal indicator bacteria during the northern migration of Sandhill Cranes (Grus canadensis) at the Central Platte River

    EPA Science Inventory

    The annual Sandhill crane (Grus canadensis) migration through Nebraska is thought to be a major source of fecal pollution to the Platte River, but of unknown human health risk. To better understand potential risks, the presence of Campylobacter species and fecal bacteria were exa...

  19. Modelling the Future Hydroclimatology of the Lower Fraser River and its Impacts on the Spawning Migration Survival of Sockeye Salmon

    NASA Technical Reports Server (NTRS)

    Hague, M. J.; Ferrari, M. R.; Miller, J. R.; Patterson, D. A.; Russell, G. L.; Farrell, A.P.; Hinch, S. G.

    2010-01-01

    Short episodic high temperature events can be lethal for migrating adult Pacific salmon (Oncorhynchus spp.). We downscaled temperatures for the Fraser River, British Columbia to evaluate the impact of climate warming on the frequency of exceeding thermal thresholds associated with salmon migratory success. Alarmingly, a modest 1.0 C increase in average summer water temperature over 100 years (1981-2000 to 2081-2100) tripled the number of days per year exceeding critical salmonid thermal thresholds (i.e. 19.0 C). Refined thresholds for two populations (Gates Creek and Weaver Creek) of sockeye salmon (Oncorhynchus nerka) were defined using physiological constraint models based on aerobic scope. While extreme temperatures leading to complete aerobic collapse remained unlikely under our warming scenario, both populations were increasingly forced to migrate upriver at reduced levels of aerobic performance (e.g. in 80% of future simulations, => 90% of salmon encountered temperatures exceeding population specific thermal optima for maximum aerobic scope; T(sub opt)) = 16.3 C for Gates Creek and T(sub sopt)=14.5 C for Weaver Creek). Assuming recent changes to river entry timing persist, we also predicted dramatic increases in the probability of freshwater mortality for Weaver Creek salmon due to reductions in aerobic, and general physiological, performance (e.g. in 42% of future simulations =>50% of Weaver Creek fish exceeded temperature thresholds associated with 0 - 60% of maximum aerobic scope). Potential for adaptation via directional selection on run-timing was more evident for the Weaver Creek population. Early entry Weaver Creek fish experienced 25% (range: 15 - 31%) more suboptimal temperatures than late entrants, compared with an 8% difference (range: 0 - 17%) between early and late Gates Creek fish. Our results emphasize the need to consider daily temperature variability in association with population-specific differences in behaviour and physiological

  20. Parameterization of meandering phenomenon in a stable atmospheric boundary layer

    NASA Astrophysics Data System (ADS)

    Carvalho, Jonas da Costa; Degrazia, Gervásio Annes; de Vilhena, Marco Túlio; Magalhães, Sergio Garcia; Goulart, Antonio G.; Anfossi, Domenico; Acevedo, Otávio Costa; Moraes, Osvaldo L. L.

    2006-08-01

    Accounting for the current knowledge of the stable atmospheric boundary layer (ABL) turbulence structure and characteristics, a new formulation for the meandering parameters to be used in a Lagrangian stochastic particle turbulent diffusion model has been derived. That is, expressions for the parameters controlling the meandering oscillation frequency in low wind speed stable conditions are proposed. The classical expression for the meandering autocorrelation function, the turbulent statistical diffusion theory and ABL similarity theory are employed to estimate these parameters. In addition, this new parameterization was introduced into a particular Lagrangian stochastic particle model, which is called Iterative Langevin solution for low wind, validated with the data of Idaho National Laboratory experiments, and compared with others diffusion models. The results of this new approach are shown to agree with the measurements of Idaho experiments and also with those of the other atmospheric diffusion models. The major advance shown in this study is the formulation of the meandering parameters expressed in terms of the characteristic scales (velocity and length scales) describing the physical structure of a turbulent stable boundary layer. These similarity formulas can be used to simulate meandering enhanced diffusion of passive scalars in a low wind speed stable ABL.

  1. Use of electromyogram telemetry to assess swimming activity of adult spring Chinook salmon migrating past a Columbia River dam

    USGS Publications Warehouse

    Brown, R.S.; Geist, D.R.; Mesa, M.G.

    2006-01-01

    Electromyogram (EMG) radiotelemetry was used to estimate the swim speeds of spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam, and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were then released below Bonneville Dam and radio-tracked as they migrated through the tailraces, fishways, and forebays of the dam. On average, swim speed was significantly higher when tagged salmon were moving through tailraces than when they were moving through other parts of the dam. Specifically, swim speeds for fish in tailraces (106.4 cm/s) were 23% higher than those of fish in fishways (84.9 cm/s) and 32% higher than those of fish in forebays (80.2 cm/s). Swim speeds were higher in fishways during the day than during the night, but there were no diel differences in swim speeds in tailraces and forebays. During dam passage, Chinook salmon spent the most time in tailraces, followed by fishways and forebays. ?? Copyright by the American Fisheries Society 2006.

  2. Use of Electromyogram Telemetry to Assess Swimmng Activity of Adult Spring Chinook Salmon Migrating Past a Columbia River Dam

    SciTech Connect

    Brown, Richard S.; Geist, David R.; Mesa, Matthew G.

    2006-02-28

    Electromyogram (EMG) radiotelemetry was used to examine the amount of energy expended by spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were then released below Bonneville Dam and radio-tracked as they migrated through the tailraces, fishways, and forebays of the dam. On average, the rate of aerobic energy used by spring Chinook salmon was significantly higher when they were moving through tailraces (1.27 kcal•kg-1•h-1) than when they were moving through other parts of the dam. Specifically, the rate of aerobic energy use for fish in tailraces was 14% higher than that used by fish in fishways (1.11 kcal•kg-1•h-1) and 27% higher than the rate used by fish in forebays (1.00 kcal•kg-1•h-1). Most (80%) of the aerobic energy used by fish to pass this dam was expended in the tailrace (25.5 kcal/kg), while only 18% (5.6 kcal/kg) and 2% (0.6 kcal/kg) were used in the fishways and forebays.

  3. Upstream Migration of Pacific Lampreys in the John Day River : Behavior, Timing, and Habitat Use : Annual Report 2000.

    SciTech Connect

    Bayer, Jennifer M.; Seelye, James G.; Robinson, T. Craig

    2001-04-12

    Historic accounts and recent observations of Pacific lampreys (Lampetra tridentata) at mainstem Columbia River dams indicate the number of Pacific lampreys migrating upriver has decreased dramatically over the last 60 years. Consequently, state, federal, and tribal governments have recently expressed concern for this species. Little is known about the biological and ecological characteristics of habitats suitable for upstream migrating Pacific lampreys. If rehabilitation efforts are to be done effectively and efficiently, we must gain knowledge of factors limiting survival and reproduction of Pacific lampreys. From data gathered in the first year of this project, we can for the first time, describe the timing, extent, and patterns of movements for Pacific lampreys. We have tested methods and gained information that will allow us to refine our objectives and approach in future work. Knowledge of behavior, timing, and the resulting quantification of habitat use will provide a means to assess the suitability of overwintering and spawning habitats and allow the establishment of goals for recovery projects. Further research is necessary, including multiple years of data collection, tracking of movement patterns through the spawning season, and more rigorously examining habitat use.

  4. Radiocesium distribution along the slope in the Iput river basin as a tracer of the contaminant secondary migration

    NASA Astrophysics Data System (ADS)

    Korobova, Elena; Romanov, Sergey; Beriozkin, Victor; Dogadkin, Nikolay

    2016-04-01

    The main goal of the study performed in 2014-2015 at the test site located in the abandoned zone of the Iput river basin was to study detailed patterns of Cs-137 redistribution along the terrace slope and the adjacent floodplain depression almost 30 years after the Chernobyl accident. Cs-137 surface activity was measured with the help of modified field gamma-spectrometer Violinist III (USA) in a grid 2 m x 2 m within the test plot sized 10 m x 24 m. Gamma-spectrometry was accompanied by topographical survey. Cs-137 depth distribution was studied by soil core sampling in increments of 2 cm and 5 cm down to 40 cm depth. Cs-137 activity in soil samples was measured in laboratory conditions by Nokia gamma-spectrometer. The results showed distinct natural dissimilarity of Cs-137 surface activity within the undisturbed soil of slope. Cs-137 depth migration in successive soil cores marked different patterns correlated with the position in relief. In particular cores Cs-137 depth variation correlated with water regime that shows that the processes of secondary distribution of Cs-137 along the slope obviously depend upon water migration. The finding is important for understanding of regularities in patterns of radiocesium spatial distribution.

  5. Diurnal characteristics of migration and transformation of mercury and effects of nitrate in Jialing River, Chongqing, China.

    PubMed

    Sun, Rongguo; Wang, Dingyong; Mao, Wen; Ma, Ming; Zhang, Cheng; Jiang, Tao

    2015-01-01

    Laboratory incubation experiments were performed to identify diurnal characteristics of migration and transformation of mercury (Hg) and effects of nitrate (NO3(-), a hydroxyl radical donor by photolysis) in Jialing River, Chongqing, China. It is found that there are strong diurnal signals of [monomethylmercury (MMHg)] and [reactive Hg (RHg)] in sediment, pore water and overlying water, which suggest that solar radiation may be an important variable that involved in aquatic Hg cycling. Photo-degradation (PD) of MMHg plays a key role in Hg cycling in water systems, and the rates are measured to be 38.22% in March, 2012. The presence of NO3(-) has a marked effect on MMHg PD under solar radiation, and affects inorganic species reducting to Hg(0), resulting in more Hg species available for methylation. So NO3(-) is an important factor for Hg cycling in water systems. Diffusive flux of MMHg, RHg and dissolved Hg (DHg) are 1.92-2.34, 3.43-3.64 and 3.04-5.71 ng m(-2) d(-1) at daytime, and 6.04-6.92, 3.22-3.25 and 7.79-8.37 ng m(-2) d(-1) at nighttime, respectively, implying that sediment is a major Hg source for shallow-water area in Jialing River at springtime. These results show great importance for understanding Hg biogeochemical processes in clear, oligotrophic, shallow, sluggish, and agriculturally-impacted waters.

  6. A barrier to upstream migration in the fish passage of Itaipu Dam (Canal da Piracema), Paraná River basin

    USGS Publications Warehouse

    ,; Fontes Júnior, Hélio Martins; Makrakis, Sergio; Gomes, Luiz Carlos; Latini, João Dirço

    2012-01-01

    The majority of the fish passages built in the Neotropical region are characterised by low efficiency and high selectivity; in many cases, the benefits to fish populations are uncertain. Studies conducted in the Canal da Piracema at Itaipu dam on the Parana River indicate that the system component designated as the Discharge channel in the Bela Vista River (herein named Canal de deságue no rio Bela Vista or CABV), a 200 m long technical section, was the main barrier to the upstream migration. The aim of this study was to evaluate the degree of restriction imposed by the CABV on upstream movements of Prochilodus lineatus and Leporinus elongatus, Characiformes. Fish were tagged with passive integrated transponders (PIT tags) and released both downstream and upstream of this critical section. Individuals of both species released downstream of the CABV took much more time to reach the upper end of the system (43.6 days vs. 15.9 days), and passed in much lower proportions (18% vs. 60.8%) than those tagged upstream of this component. Although more work is needed to differentiate between fishway effects and natural variation in migratory motivation, the results clearly demonstrate passage problems at the CABV.

  7. Smolt Migration Characteristics and Mainstem Snake and Columbia River Detection Rates of PIT-Tagged Grande Ronde and Imnaha River Naturally-Produced Spring Chinook Salmon, 1996 Annual Report : Fish Research Project, Oregon.

    SciTech Connect

    Sankovich, Paul; Keefe, MaryLouise; Carmichael, Richard W.

    1997-01-01

    This is the fifth year of a multi-year study to assess smolt migration characteristics and cumulative detection rates of naturally-produced chinook salmon (Oncorhynchus tshawytscha), from northeast Oregon streams. The goal of this project is to develop an understanding of interpopulation and interannual variation in several early life history characteristics of naturally-produced chinook salmon from the Grande Ronde and Imnaha River subbasins. This project provides information useful in the recovery of listed Snake River spring/summer chinook salmon. Specific populations included in the study are (1) Catherine Creek, (2) upper Grande Ronde River, (3) Lostine River, (4) Imnaha River, (5) Wenaha River, and (6) Minam River. In this document, we present findings from research completed in 1996. Naturally-produced chinook salmon populations in the Grande Ronde and Imnaha River subbasins have declined drastically in recent years due in part to habitat alterations and hydropower development. Declines have continued despite extensive mitigation efforts, including fish passage improvements, artificial production, supplementation, and habitat modification (BPA Division of Fish and Wildlife 1990). Snake River spring/summer chinook salmon (hereafter referred to as chinook salmon), which include naturally-produced chinook salmon in the Grande Ronde and Imnaha River subbasins, have been listed under the Endangered Species Act of 1973 as threatened or endangered since 1992.

  8. The Importance of Paleohydrologic Analysis to Guide River Restoration After Dam Removal, Ottawa River, NW Ohio

    NASA Astrophysics Data System (ADS)

    Evans, J. E.; Harris, N.; Webb, L. D.

    2010-12-01

    The Secor Dam was a low-head weir on an urbanized river that was constructed in 1928 and removed in 2007 for a variety of reasons: (1) it was obsolete and a potential liability to the owner, (2) removal would enhance aquatic ecosystems and fisheries, and (3) removal would improve downstream water quality and help restore downstream sediment budgets. In sum, it was a “river restoration” effort in an urbanized river corridor, with extensive public involvement. Detailed pre- and post-dam removal studies included field sedimentological methods such as trenching and sediment coring. Historical documents assisted in locating the pre-1928 channel and documented that urbanization of this region post-1928 resulted in channel armoring. Detailed channel surveys showed that the result of the dam removal was initial incision and channel widening in the former reservoir, as expected. However, nickzone migration upstream stalled on an exhumed woody peat layer. Studies subsequently showed that this was a hydromorphic paleosol that developed during pre-land clearance times that was buried beneath 2.5-m of anthropogenic or legacy sediments, much of that deposited since about 1950. Today, the river flows through an incised channel between fill-terraces comprised of legacy sediments. Additional coring and survey work documented that the channel lateral migration rates averaged 0.32 m/yr over the past approximately 80 years, and that the meander wavelength appears to be changing in response to dam removal. Public hearings about “river restoration” made it clear that the public has a vision of a restored river that in fact never existed. Significant channel bank erosion and lateral channel migration should be expected until such time as the river system reworks and removes accumulated legacy sediments currently in intrabasinal storage. This finding has important implications in an urbanized setting, where bank erosion is perceived to be a threat to infrastructure and property

  9. Migration of global radioactive fallout to the Arctic Ocean (on the example of the Ob's river drainage basin).

    PubMed

    Miroshnikov, A; Semenkov, I

    2012-11-01

    This article provides an assessment of the impact of global fallout on (137)Cs contamination in the bottom sediments of Kara Sea. The erosiveness of 10th-level river basins was estimated by landscape-geochemical and geomorphological characteristics. All 10th-level basins (n=154) were separated into three groups: mountain, mountain-lowland and plain. Four different types of basins were identified depending on the geochemical conditions of the migration of radiocaesium in the plain and mountain-lowland. Classifications of types were carried out using the geographic information systems-based approach. The Ob River's macroarena covers 3.5 million km(2). Internal drainage basins cover 23 % of the macroarena and accumulate whole radiocaesium from the global fallout. The remaining territory is transitional for the (137)Cs. The field research works performed in the three plain first-level basins allow one to estimate the radiocaesium run-off. The calculations show that 7 % of (137)Cs was removed from the first-level basin in arable land. Accumulation of radiocaesium in the first-level basin under undisturbed forest is 99.8 %. The research shows that (137)Cs transfer from the humid basins is in the range of 6.9-25.5 TBq and for semi-humid basins 5.6-285.5 TBq. The areas of these basins cover 40 and 8 % of the Ob River's macroarena, respectively. Drainage lakes and reservoir drainage basins make up 22 % of the macroarena. Mountainous and semi-arid drainage basins cover 7 % of the macroarena.

  10. Design and implementation of an emergency environmental responsesystem to protect migrating salmon in the lower San Joaquin River,California

    SciTech Connect

    Quinn, Nigel W.T.; Jacobs, Karl C.

    2006-01-30

    In the past decade tens of millions of dollars have beenspent by water resource agencies in California to restore the nativesalmon fishery in the San Joaquin River and its major tributaries. Anexcavated deep water ship channel (DWSC), through which the river runs onits way to the Bay/Delta and Pacific Ocean, experiences episodes of lowdissolved oxygen which acts as a barrier to anadromous fish migration anda threat to the long-term survival of the salmon run. An emergencyresponse management system is under development to forecast theseepisodes of low dissolved oxygen and to deploy measures that will raisedissolved oxygen concentrations to prevent damage to the fisheryresource. The emergency response management system has been designed tointeract with a real-time water quality monitoring network and is servedby a comprehensive data management and forecasting model toolbox. TheBay/Delta and Tributaries (BDAT) Cooperative Data Management System is adistributed, web accessible database that contains terabytes ofinformation on all aspects of the ecology of the Bay/Delta and upperwatersheds. The complexity of the problem dictates data integration froma variety of monitoring programs. A unique data templating system hasbeen constructed to serve the needs of cooperating scientists who wish toshare their data and to simplify and streamline data uploading into themaster database. In this paper we demonstrate the utility of such asystem in providing decision support for management of the San JoaquinRiver fishery. We discuss how the system might be expanded to havefurther utility in coping with other emergencies and threats to watersupply system serving California's costal communities.

  11. Flow and sediment processes in a cutoff meander of the Danube Delta during 100-year recurrent flood

    NASA Astrophysics Data System (ADS)

    Jugaru Tiron, L.; Le Coz, J.; Provansal, M.; Dutu, F.

    2009-04-01

    River training operations, such as meander cutoff, initiated for navigational purposes often lead to dramatic changes in the streamwise profiles (Hooke, 1986, Kesel, 2003; Kiss et al., 2007). Meander correction affects both the hydraulic and morphodynamical behavior of the modified branches that sedimentation occurs in time, while newly built canals usually experience degradation (Jugaru et. al, 2006). This study reports and analyzes new data on the hydrological and sedimentary processes at work during a morphogenic flood in a large modified meander (the Mahmudia meander) of the St. George branch, the southern branch of the Danube Delta. The 100-year recurrent flood that occurred in 2006 offered an exceptional opportunity for scanning different cross sections of the Mahmudia meander system by means of the emerging Doppler profiler (aDcp) technology in order to analyze the impact on sedimentation and dynamic processes in the study area. The Mahmudia study site corresponds to a vast natural meander which was cut off in 1984-1988 by an artificial canal opened to shipping. The meander correction accelerated fluxes through the artificial canal and dramatically enhanced deposition in the former meander. After his formation, the cutoff meander acted as sediment storage locations, essentially removing channel and point bar sediments from the active sediment budget of the main channel (Popa, 1997). During the one-hundred-year recurrent flood in April 2006, bathymetry, flow velocity and discharge data were acquired across several sections of both natural and artificial channels with an acoustic Doppler current profiler (aDcp Workhorse Sentinel 600 kHz, Teledyne RDI) in order to investigate the distribution of the flow and sediment and his impact on sedimentation in a channelized reach and its adjacent cutoff. The contrasting hydro-sedimentary processes at work in both channels and bifurcation/confluence nodal points are analyzed from the measured flux distribution

  12. Radionuclide migration at the Koongarra uranium deposit, Northern Australia Lessons from the Alligator Rivers analogue project

    NASA Astrophysics Data System (ADS)

    Payne, Timothy E.; Airey, Peter L.

    The Koongarra uranium deposit in Northern Australia provides a ‘natural analogue’ for processes that are of relevance for assessing the safety of radioactive waste disposal. In an international project extending over two decades, the Koongarra ore body was studied to increase the understanding of radionuclide migration and retention mechanisms that might occur in the vicinity of a geological repository. The research effort included extensive characterisation of the geological, hydrological and geochemical conditions at the site. Patterns of the distribution of radionuclides (predominantly members of the 238U decay chain, but also the rare isotopes 239Pu, 99Tc and 129I) were studied in both solid and groundwater phases. The project included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to long-term uranium immobilisation. Numerous models for uranium migration were developed during the project. This paper provides a comprehensive review of the research at Koongarra, and assesses the value of the site for integrating the results of a complex series of laboratory, modelling and field studies. The insights gained from this review of the Koongarra project may assist in maximising the potential scientific benefit of future natural analogue studies.

  13. Employing the Hilbert-Huang Transform to analyze observed natural complex signals: Calm wind meandering cases

    NASA Astrophysics Data System (ADS)

    Martins, Luis Gustavo Nogueira; Stefanello, Michel Baptistella; Degrazia, Gervásio Annes; Acevedo, Otávio Costa; Puhales, Franciano Scremin; Demarco, Giuliano; Mortarini, Luca; Anfossi, Domenico; Roberti, Débora Regina; Denardin, Felipe Costa; Maldaner, Silvana

    2016-11-01

    In this study we analyze natural complex signals employing the Hilbert-Huang spectral analysis. Specifically, low wind meandering meteorological data are decomposed into turbulent and non turbulent components. These non turbulent movements, responsible for the absence of a preferential direction of the horizontal wind, provoke negative lobes in the meandering autocorrelation functions. The meandering characteristic time scales (meandering periods) are determined from the spectral peak provided by the Hilbert-Huang marginal spectrum. The magnitudes of the temperature and horizontal wind meandering period obtained agree with the results found from the best fit of the heuristic meandering autocorrelation functions. Therefore, the new method represents a new procedure to evaluate meandering periods that does not employ mathematical expressions to represent observed meandering autocorrelation functions.

  14. Plasma insulin-like growth factor-I concentrations in yearling chinook salmon (Oncorhynchus tshawytscha) migrating from the Snake River Basin, USA

    USGS Publications Warehouse

    Congleton, J.L.; Biga, P.R.; Peterson, B.C.

    2003-01-01

    During the parr-to-smolt transformation (smoltification) of juvenile salmonids, preadaptive changes in osmoregulatory and ionoregulatory ability are regulated in part by the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis. If food intake is sufficient, plasma IGF-I increases during smoltification. On the other hand, plasma IGF-I typically decreases in fasting fish and other vertebrate animals. Because food availability is limited for juvenile salmonids undertaking an extended 6- to 12-week spring migration to and through the Snake-Columbia River hydropower system (northwestern USA), IGF-I concentrations might be expected to decrease, potentially compromising seawater tolerance. To address this possibility, yearling chinook salmon Oncorhynchus tshawytscha reared in three Snake River Basin hatcheries were sampled before release and at two downstream dams. Dry masses of migrating fish either did not increase during the migration (in 2000, an average-flow year), or decreased significantly (in 2001, a low-flow year). In both years, plasma IGF-I levels were significantly higher (1.6-fold in 2000, 3.7-fold in 2001) for fish sampled at the last dam on the lower Columbia River than for fish sampled prior to release. Plasma IGF-I concentrations in migrating fish may, nonetheless, have been nutritionally down-regulated to some degree, because plasma IGF-I concentrations in juvenile chinook salmon captured at a Snake River dam and transported to the laboratory increased in fed groups, but decreased in unfed groups. The ability of migrating smolts to maintain relatively elevated IGF-I levels despite restricted food intake and loss of body mass is likely related to smoltification-associated changes in hormonal balance. ?? 2004 Kluwer Academic Publishers.

  15. Accumulation of polychlorinated biphenyls in american shad during their migration in the Hudson River, spring 1977.

    PubMed

    Pastel, M; Bush, B; Kim, J S

    1980-06-01

    Fifty-two female American shad (Alosa sapidissima) were collected during the spring of 1977 at two sites on the lower Hudson River, 27 miles and 75 miles from the river mouth. The fish were extracted with hexane, and the extracts were analyzed by electron-capture gas chromatography (EC-GC) and by GC/mass spectrometry (MS), PCBs were quantitated by EC-GC, and the concentrations were compared by fish length and by site. Fish collected from the downstream site contained a mean PCB concentration of 2.0 +/- 1.0 microgram/g, wet weight; fish from the upstream site contained a mean PCB concentration of 6.1 +/- 2.6 microgram/g, wet weight. Aliquots of the hexane extracts were fractionated before analysis by GC/MS. The presence of PCBs was confirmed, and DDE and the alkane series from C22 through C26 were detected. American shad are saltwater fish that only enter fresh water to spawn. Because they do not feed in fresh water before spawning, they may be used as an indicator of water contamination.

  16. Movements and Distribution of Northern Squawfish Downstream of Lower Snake River Dams Relative to the Migration of Juvenile Salmonids, 1992-1993 Completion Report.

    SciTech Connect

    Isaak, D.J.; Bjornn, T.C.

    1996-03-01

    Northern squawfish Ptychocheilus oregonensis movements were monitored downstream of two lower Snake River dams during the juvenile salmonid migrations of 1992 and 1993. During a high flow year in 1993, the abundance of squawfish in the tailrace of Lower Granite Dam peaked in July, after the majority of juveniles had moved past Lower Granite Dam, and peak abundance was inversely related to river discharge. Few squawfish moved into the tailrace of Ice Harbor Dam in 1993 because of the extended period of spill. Distributions of squawfish in the tailrace of Lower Granite Dam varied between and within years and shifted in response to changing prey densities, flow patterns, water temperature, and diel cycles, but fish consistently used low velocity habitats. Data from Ice Harbor Dam is less extensive, but squawfish distributions there appeared to be affected by changing flow patterns and fish used low velocity habitats. The changes in distribution and abundance of squawfish in tailrace areas are evidence that predation on seaward migrating salmonids depends on the timing of migration and size and timing of runoff. Juvenile salmonids migrating in the spring and early summer will probably be less affected by squawfish predation in tailrace areas than salmon that migrate later in the summer.

  17. Determination of Swimming Speeds and Energetic Demands of Upriver Migrating Fall Chinook Salmon (Oncorhynchus tshawytscha) in the Klickitat River, Washington

    SciTech Connect

    Brown, Richard S.; Geist, David R.

    2002-07-01

    This report describes a field study by PNNL for Bonneville Power Administration in fall 2001 to study the migration and energy use of adult fall chinook salmon traveling up the Klickitat River to spawn. The salmon were tagged with surgically implanted electromyogram transmitters or gastrically implanted coded transmitters. Swim speed and aerobic and anaerobic energy use were determined for the fish as they attempted to pass three waterfalls on the lower Klickitat and as they traversed free-flowing stretches between and below the falls. Of the 35 EMG-tagged fish released near the mouth of the Klickitat, 40% passed the first falls, 36% passed the second falls, and 20% reached Lyle Falls but were unable to leap over. Mean swimming speeds ranged from as low as 52.6 cm/sec between falls to as high as 158.1 cm/sec at falls passage. Fish exhibited a higher percentage of occurrences of burst swimming while passing the falls than while between falls (58.9% versus 1.7%). However, fish expended more energy swimming the stretches between the falls than during actual falls passage (52.3-236.2 kcals versus 0.3-1.1 kcals). Male-female and day-night differences in falls passage success were noted. PNNL also examined energy costs and swimming speeds for fish released above Lyle Falls as they migrated to upstream spawning areas. This journey averaged 15.93 days at a mean rate of 2.36 km/day to travel a mean maximum of 37.6 km upstream at a total energy cost of approx 4,492 kcals (32% anaerobic/68% aerobic). When the salmon have expended the estimated 968 kcals needed to get through Bonneville Dam and the three falls on the Lower Klickitat, plus this 4,492 kcals to reach the spawning grounds, they are left with approximately 8 to 12% (480 to 742 kcals) of their energy reserves for spawning. A delay of 4 to 7 days along the lower Klickitat River could deplete their remaining energy reserves (at a rate of about 103 kcals/day), resulting in death before spawning would occur.

  18. Optimization of meander line antennas for RFID applications by using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Bucuci, Stefania C.; Anchidin, Liliana; Dumitrascu, Ana; Danisor, Alin; Berescu, Serban; Tamas, Razvan D.

    2015-02-01

    In this paper, we propose an approach of optimization of meander line antennas by using genetic algorithm. Such antennas are used in RFID applications. As opposed to other approaches for meander antennas, we propose the use of only two optimization objectives, i.e. gain and size. As an example, we have optimized a single meander dipole antenna, resonating at 869 MHz.

  19. Changes in meandering of the Northern Hemisphere circulation

    NASA Astrophysics Data System (ADS)

    Di Capua, Giorgia; Coumou, Dim

    2016-09-01

    Strong waves in the mid-latitude circulation have been linked to extreme surface weather and thus changes in waviness could have serious consequences for society. Several theories have been proposed which could alter waviness, including tropical sea surface temperature anomalies or rapid climate change in the Arctic. However, so far it remains unclear whether any changes in waviness have actually occurred. Here we propose a novel meandering index which captures the maximum waviness in geopotential height contours at any given day, using all information of the full spatial position of each contour. Data are analysed on different time scale (from daily to 11 day running means) and both on hemispheric and regional scales. Using quantile regressions, we analyse how seasonal distributions of this index have changed over 1979-2015. The most robust changes are detected for autumn which has seen a pronounced increase in strongly meandering patterns at the hemispheric level as well as over the Eurasian sector. In summer for both the hemisphere and the Eurasian sector, significant downward trends in meandering are detected on daily timescales which is consistent with the recently reported decrease in summer storm track activity. The American sector shows the strongest increase in meandering in the warm season: in particular for 11 day running mean data, indicating enhanced amplitudes of quasi-stationary waves. Our findings have implications for both the occurrence of recent cold spells and persistent heat waves in the mid-latitudes.

  20. Comparative evaluation of molecular diagnostic tests for Nucleospora salmonis and prevalence in migrating juvenile salmonids from the Snake River, USA

    USGS Publications Warehouse

    Badil, Samantha; Elliott, Diane G.; Kurobe, Tomofumi; Hedrick, Ronald P.; Clemens, Kathy; Blair, Marilyn; Purcell, Maureen K.

    2011-01-01

    Nucleospora salmonis is an intranuclear microsporidian that primarily infects lymphoblast cells and contributes to chronic lymphoblastosis and a leukemia-like condition in a range of salmonid species. The primary goal of this study was to evaluate the prevalence of N. salmonis in out-migrating juvenile hatchery and wild Chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss from the Snake River in the U.S. Pacific Northwest. To achieve this goal, we first addressed the following concerns about current molecular diagnostic tests for N. salmonis: (1) nonspecific amplification patterns by the published nested polymerase chain reaction (nPCR) test, (2) incomplete validation of the published quantitative PCR (qPCR) test, and (3) whether N. salmonis can be detected reliably from nonlethal samples. Here, we present an optimized nPCR protocol that eliminates nonspecific amplification. During validation of the published qPCR test, our laboratory developed a second qPCR test that targeted a different gene sequence and used different probe chemistry for comparison purposes. We simultaneously evaluated the two different qPCR tests for N. salmonis and found that both assays were highly specific, sensitive, and repeatable. The nPCR and qPCR tests had good overall concordance when DNA samples derived from both apparently healthy and clinically diseased hatchery rainbow trout were tested. Finally, we demonstrated that gill snips were a suitable tissue for nonlethal detection of N. salmonis DNA in juvenile salmonids. Monitoring of juvenile salmonid fish in the Snake River over a 3-year period revealed low prevalence of N. salmonis in hatchery and wild Chinook salmon and wild steelhead but significantly higher prevalence in hatchery-derived steelhead. Routine monitoring of N. salmonis is not performed for all hatchery steelhead populations. At present, the possible contribution of this pathogen to delayed mortality of steelhead has not been determined.

  1. Instream Flows Needed for Successful Migration Spawning and Rearing of Rainbow and Westslope Cutthroat Trout in Selected Tributaries of the Kootenai River: Final Report 1986.

    SciTech Connect

    Marotz, Brian

    1986-12-01

    This study was conducted by Montana Department of Fish, Wildlife and Parks in contractual agreement with Bonneville Power Administration and addresses measure 804(a)(9) of the Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program. Objectives were to determine instream flow needs in Kootenai River tributaries to maintain successful fish migration, spawning and rearing habitat of game fish, evaluate existing resident and rearing fish populations, and compile hydrologic and fishery information required to secure legal reservation of water for the fishery resource.

  2. Influence of Riparian Tree Phenology on Lower Colorado River Spring-Migrating Birds: Implications of Flower Cueing

    USGS Publications Warehouse

    McGrath, Laura J.; van Riper, Charles

    2005-01-01

    Executive Summary Neotropical migrant birds make choices about which habitats are most likely to provide successful foraging locations during migration, but little is known about how these birds recognize and process environmental clues that indicate the presence of prey species. Aspects of tree phenology, notably flowering of trees along the lower Colorado River corridor, coincide with the migratory stopovers of leaf-gleaning insectivorous songbirds and may be an important indicator of arthropod prey species availability. Shifting tree flowering and leaf flush during the spring migration period presents avian insectivores with an assortment of foraging opportunities. During two field seasons at Cibola National Wildlife Refuge in southwestern Arizona, we examined riparian tree species to test whether leaf-gleaning insectivorous birds are attracted to the flowering condition of trees in choosing foraging sites. We predicted that flowering trees would host more insect prey resources, would thus show increased visit rates, length of stays and attack ratios of migrant avian insectivores, and that those arthropods would be found in the stomach contents of the birds. Paired trees of honey mesquite (Prosopis glandulosa), displaying heavy and light degrees of flowering were observed to test these predictions. To test whether birds are tracking arthropods directly or are using flowers as a proximate cue, we removed flowers from selected trees and paired these treated trees with neighboring high flowering trees, which served as controls. Avian foraging behavior, avian diets, arthropods, and phenology data were collected at the same time to control for temporal differences in insect availability, plant phenology, and differences in stopover arrivals of birds. We documented five patterns from this study: 1) Higher abundance and richness of arthropods were found on honey mesquite trees with greater numbers of flowers. 2) Arthropod abundance and richness increased as flowering

  3. The feasibility of population migration from arid mountainous areas of Central Gansu to the oasis west of the Yellow River in the province.

    PubMed

    Chen, B; Zhang, Z; Yuan, H

    1991-01-01

    This article on population migration from Central Gansu, China, which is made up of 18 impoverished counties in Dingxi Region, to Hexi in the Yellow River Valley focuses on the basic mechanisms and characteristics of population migration, the effects of migration on adaptability, the return rate, and the socioeconomic and ecological benefits of migration. Analysis is based on logical deduction and empirical evidence. The reasons for migration are poverty and unchecked population growth. Population in Central Gansu doubled (110.1%) between 1952-83, while the population in the province increased 86.67% and in the country 83.52%. Per capita grain allocations in Dingxi and the marginal utility of agricultural production declined. Population pressure led to short supplies of food and fuel and excessive land reclamation, which produced soil erosion, and a downward spiral. Migrants were attracted to Hexi because of favorable farming conditions and a developed economy. Subsidies were used to encourage people to migrate voluntarily. 31,485 people migrated to the Hexi Corridor in 1988. 4450 came from Huining County and 3743 from Dingxi. Most went to Jiuquan (17,490 people), and 7,357 migrated to Zhongye, both areas with good irrigation facilities. 78.33% of the migrants were individually placed and 21.67% were placed as groups in "hanging" villages of 320/village. The inter-regional migration rate was 85.27% between 1983-86 in Jiuquan region, or 14,000 people. Migrants found their living conditions to be greatly improved. Per capita income increased 12.8 times from 497.5 yuan in 1983, while the income of nonmigrants underwent only a 4.45-fold increase. There were also differences in grain allocation. Jiuquan had a low return migration rate of 14.73% between 1983-86. Variations occur from region to region due to excessive economic disparity, incomplete basic facilities, and forced group migration. The annual yield of investment in migration was 19.87%, which makes the

  4. Critical role for macrophage migration inhibitory factor (MIF) in Ross River virus-induced arthritis and myositis.

    PubMed

    Herrero, Lara J; Nelson, Michelle; Srikiatkhachorn, Anon; Gu, Ran; Anantapreecha, Surapee; Fingerle-Rowson, Günter; Bucala, Richard; Morand, Eric; Santos, Leilani L; Mahalingam, Suresh

    2011-07-19

    Arthrogenic alphaviruses, such as Ross River virus (RRV), chikungunya, Sindbis, mayaro and o'nyong-nyong viruses circulate endemically worldwide, frequently causing outbreaks of polyarthritis. The exact mechanisms of how alphaviruses induce polyarthritis remain ill defined, although macrophages are known to play a key role. Macrophage migration inhibitory factor (MIF) is an important cytokine involved in rheumatoid arthritis pathogenesis. Here, we characterize the role of MIF in alphavirus-induced arthritides using a mouse model of RRV-induced arthritis, which has many characteristics of RRV disease in humans. RRV-infected WT mice developed severe disease associated with up-regulated MIF expression in serum and tissues, which corresponded to severe inflammation and tissue damage. MIF-deficient (MIF(-/-)) mice developed mild disease accompanied by a reduction in inflammatory infiltrates and muscle destruction in the tissues, despite having viral titers similar to WT mice. In addition, reconstitution of MIF into MIF(-/-) mice exacerbated RRV disease and treatment of mice with MIF antagonist ameliorated disease in WT mice. Collectively, these findings suggest that MIF plays a critical role in determining the clinical severity of alphavirus-induced musculoskeletal disease and may provide a target for the development of antiviral pharmaceuticals. The prospect being that early treatment with MIF-blocking pharmaceuticals may curtail the debilitating arthritis associated with alphaviral infections.

  5. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2003-2004 Annual Report.

    SciTech Connect

    Smith, Steven G.; Muir, William D.; Zabel, Richard W.

    2004-01-01

    For juvenile chinook salmon Oncorhynchus tshawytscha, sockeye salmon O. nerka, and steelhead O. mykiss that migrate through reservoirs, hydroelectric projects, and free-flowing sections of the Snake and Columbia Rivers, survival estimates are essential to develop effective strategies for recovering depressed stocks. Many management strategies were based on estimates of system survival (Raymond 1979; Sims and Ossiander 1981) derived in a river system considerably different from today's (Williams and Matthews 1995; Williams et al. 2001). Knowledge of the magnitude, locations, and causes of smolt mortality under present passage conditions, and under conditions projected for the future, are necessary to develop strategies that will optimize smolt survival during migration. From 1993 through 2002, the National Marine Fisheries Service (NMFS) and the University of Washington (UW) demonstrated the feasibility of using three statistical models to estimate survival of PIT-tagged (Prentice et al. 1990a) juvenile salmonids passing through Snake River dams and reservoirs (Iwamoto et al. 1994; Muir et al. 1995, 1996, 2001a, 2003; Smith et al. 1998, 2000a,b; Hockersmith et al. 1999; Zabel et al. 2001, 2002). Evaluation of assumptions for these models indicated that all were generally satisfied, and accurate and precise survival estimates were obtained. In 2003, NMFS and UW completed the eleventh year of the study. Flow levels during the early portion of the 2003 spring migration were similar to 2002, and only slightly higher than in the drought conditions during 2001. However, flow levels were much greater during the later part of the migration in 2003. Spill levels were similar to 2002, much higher than in 2001. Research objectives were to: (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate

  6. Potential Effects of Hydroelectric Dam Development in the Mekong River Basin on the Migration of Siamese Mud Carp (Henicorhynchus siamensis and H. lobatus) Elucidated by Otolith Microchemistry

    PubMed Central

    Fukushima, Michio; Jutagate, Tuantong; Grudpan, Chaiwut; Phomikong, Pisit; Nohara, Seiichi

    2014-01-01

    The migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus), two of the most economically important fish species in the Mekong River, was studied using an otolith microchemistry technique. Fish and river water samples were collected in seven regions throughout the whole basin in Thailand, Laos and Cambodia over a 4 year study period. There was coherence between the elements in the ambient water and on the surface of the otoliths, with strontium (Sr) and barium (Ba) showing the strongest correlation. The partition coefficients were 0.409–0.496 for Sr and 0.055 for Ba. Otolith Sr-Ba profiles indicated extensive synchronized migrations with similar natal origins among individuals within the same region. H. siamensis movement has been severely suppressed in a tributary system where a series of irrigation dams has blocked their migration. H. lobatus collected both below and above the Khone Falls in the mainstream Mekong exhibited statistically different otolith surface elemental signatures but similar core elemental signatures. This result suggests a population originating from a single natal origin but bypassing the waterfalls through a passable side channel where a major hydroelectric dam is planned. The potential effects of damming in the Mekong River are discussed. PMID:25099147

  7. Potential effects of hydroelectric dam development in the Mekong River basin on the migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus) elucidated by otolith microchemistry.

    PubMed

    Fukushima, Michio; Jutagate, Tuantong; Grudpan, Chaiwut; Phomikong, Pisit; Nohara, Seiichi

    2014-01-01

    The migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus), two of the most economically important fish species in the Mekong River, was studied using an otolith microchemistry technique. Fish and river water samples were collected in seven regions throughout the whole basin in Thailand, Laos and Cambodia over a 4 year study period. There was coherence between the elements in the ambient water and on the surface of the otoliths, with strontium (Sr) and barium (Ba) showing the strongest correlation. The partition coefficients were 0.409-0.496 for Sr and 0.055 for Ba. Otolith Sr-Ba profiles indicated extensive synchronized migrations with similar natal origins among individuals within the same region. H. siamensis movement has been severely suppressed in a tributary system where a series of irrigation dams has blocked their migration. H. lobatus collected both below and above the Khone Falls in the mainstream Mekong exhibited statistically different otolith surface elemental signatures but similar core elemental signatures. This result suggests a population originating from a single natal origin but bypassing the waterfalls through a passable side channel where a major hydroelectric dam is planned. The potential effects of damming in the Mekong River are discussed.

  8. Distribution and Joint Fish-Tag Survival of Juvenile Chinook Salmon Migrating through the Sacramento-San Joaquin River Delta, California, 2008

    USGS Publications Warehouse

    Holbrook, Christopher M.; Perry, Russell W.; Adams, Noah S.

    2009-01-01

    Acoustic telemetry was used to obtain the movement histories of 915 juvenile fall-run Chinook salmon (Oncorhynchus tshawytscha) through the lower San Joaquin River and Sacramento-San Joaquin Delta, California, in 2008. Data were analyzed within a release-recapture framework to estimate survival, route distribution, and detection probabilities among three migration pathways through the Delta. The pathways included the primary route through the San Joaquin River and two less direct routes (Old River and Turner Cut). Strong inferences about survival were limited by premature tag failure, but estimates of fish distribution among migration routes should be unaffected by tag failure. Based on tag failure tests (N = 66 tags), we estimated that only 55-78 percent of the tags used in this study were still functioning when the last fish was detected exiting the study area 15 days after release. Due to premature tag failure, our 'survival' estimates represent the joint probability that both the tag and fish survived, not just survival of fish. Low estimates of fish-tag survival could have been caused by fish mortality or fish travel times that exceeded the life of the tag, but we were unable to differentiate between the two. Fish-tag survival through the Delta (from Durham Ferry to Chipps Island by all routes) ranged from 0.05 +or- 0.01 (SE) to 0.06 +or- 0.01 between the two weekly release groups. Among the three migration routes, fish that remained in the San Joaquin River exhibited the highest joint fish-tag survival (0.09 +or- 0.02) in both weeks, but only 22-33 percent of tagged fish used this route, depending on the week of release. Only 4-10 percent (depending on week) of tagged fish traveled through Turner Cut, but no tagged fish that used this route were detected exiting the Delta. Most fish (63-68 percent, depending on week of release) migrated through Old River, but fish-tag survival through this route (0.05 +or- 0.01) was only about one-half that of fish that

  9. Use of aquaculture ponds and other habitats by autumn migrating shorebirds along the lower Mississippi river.

    PubMed

    Lehnen, Sarah E; Krementz, David G

    2013-08-01

    Populations of many shorebird species are declining; habitat loss and degradation are among the leading causes for these declines. Shorebirds use a variety of habitats along interior migratory routes including managed moist soil units, natural wetlands, sandbars, and agricultural lands such as harvested rice fields. Less well known is shorebird use of freshwater aquaculture facilities, such as commercial cat- and crayfish ponds. We compared shorebird habitat use at drained aquaculture ponds, moist soil units, agricultural areas, sandbars and other natural habitat, and a sewage treatment facility in the in the lower Mississippi River Alluvial Valley (LMAV) during autumn 2009. Six species: Least Sandpiper (Calidris minutilla), Killdeer (Charadrius vociferous), Semipalmated Sandpiper (Calidris pusilla), Pectoral Sandpiper (C. melanotos), Black-necked Stilt (Himantopus himantopus), and Lesser Yellowlegs (Tringa flavipes), accounted for 92 % of the 31,165 individuals observed. Sewage settling lagoons (83.4, 95 % confidence interval [CI] 25.3-141.5 birds/ha), drained aquaculture ponds (33.5, 95 % CI 22.4-44.6 birds/ha), and managed moist soil units on public lands (15.7, CI 11.2-20.3 birds/ha) had the highest estimated densities of shorebirds. The estimated 1,100 ha of drained aquaculture ponds available during autumn 2009 provided over half of the estimated requirement of 2,000 ha by the LMAV Joint Venture working group. However, because of the decline in the aquaculture industry, autumn shorebird habitats in the LMAV may be limited in the near future. Recognition of the current aquaculture habitat trends will be important to the future management activities of federal and state agencies. Should these aquaculture habitat trends continue, there may be a need for wildlife biologists to investigate other habitats that can be managed to offset the current and expected loss of aquaculture acreages. This study illustrates the potential for freshwater aquaculture to

  10. Use of Aquaculture Ponds and Other Habitats by Autumn Migrating Shorebirds Along the Lower Mississippi River

    NASA Astrophysics Data System (ADS)

    Lehnen, Sarah E.; Krementz, David G.

    2013-08-01

    Populations of many shorebird species are declining; habitat loss and degradation are among the leading causes for these declines. Shorebirds use a variety of habitats along interior migratory routes including managed moist soil units, natural wetlands, sandbars, and agricultural lands such as harvested rice fields. Less well known is shorebird use of freshwater aquaculture facilities, such as commercial cat- and crayfish ponds. We compared shorebird habitat use at drained aquaculture ponds, moist soil units, agricultural areas, sandbars and other natural habitat, and a sewage treatment facility in the in the lower Mississippi River Alluvial Valley (LMAV) during autumn 2009. Six species: Least Sandpiper ( Calidris minutilla), Killdeer ( Charadrius vociferous), Semipalmated Sandpiper ( Calidris pusilla), Pectoral Sandpiper ( C. melanotos), Black-necked Stilt ( Himantopus himantopus), and Lesser Yellowlegs ( Tringa flavipes), accounted for 92 % of the 31,165 individuals observed. Sewage settling lagoons (83.4, 95 % confidence interval [CI] 25.3-141.5 birds/ha), drained aquaculture ponds (33.5, 95 % CI 22.4-44.6 birds/ha), and managed moist soil units on public lands (15.7, CI 11.2-20.3 birds/ha) had the highest estimated densities of shorebirds. The estimated 1,100 ha of drained aquaculture ponds available during autumn 2009 provided over half of the estimated requirement of 2,000 ha by the LMAV Joint Venture working group. However, because of the decline in the aquaculture industry, autumn shorebird habitats in the LMAV may be limited in the near future. Recognition of the current aquaculture habitat trends will be important to the future management activities of federal and state agencies. Should these aquaculture habitat trends continue, there may be a need for wildlife biologists to investigate other habitats that can be managed to offset the current and expected loss of aquaculture acreages. This study illustrates the potential for freshwater aquaculture to

  11. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2000 Annual Report.

    SciTech Connect

    Zabel, Richard; Smith, Steven G.; Muir, William D.

    2001-02-01

    In 2000, the National Marine Fisheries Service and the University of Washington completed the eight year of a study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. A total of 20,313 hatchery steelhead were tagged with passive integrated transpoder (PIT) tags and released at Lower Granite Dam for reach survival estimation. They did not PIT tag any yearlying chinook salmon (O. tshawytscha) for reach survival estimates in 2000 because sufficient numbers for these estimates were available from other studies. Primary research objectives in 2000 were (1) to estimate reach and project survival in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations, and (2) to evaluate the survival-estimation models under prevailing conditions. In addition, they estimated survival from point of release to Lower Granite Dam and below for chinook salmon, steelhead, and sockeye salmon (O.nerka) PIT tagged and released at Snake River basin hatcheries and chinook salmon and steelhead PIT tagged and released at Snake River basin hatcheries and chinook salmon and steelhead PIT tagged and released at Snake River basin smolt traps. This report provides reach survival and travel time estimates for 2000 for PIT-tagged yearling chinook salmon and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures. Further details on methodology and statistical models used are provided in previous reports cited in the text.

  12. Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Juveniles, 2007-2008 Report of Research.

    SciTech Connect

    Achord, Stephen; Sandford, Benjamin P.; Hockersmith, Eric E.

    2009-05-26

    This report provides results from an ongoing project to monitor the migration behavior and survival of wild juvenile spring/summer Chinook salmon in the Snake River Basin. Data reported is from detections of PIT tagged fish during late summer 2007 through mid-2008. Fish were tagged in summer 2007 by the National Marine Fisheries Service (NMFS) in Idaho and by the Oregon Department of Fish and Wildlife (ODFW) in Oregon. Our analyses include migration behavior and estimated survival of fish at instream PIT-tag monitors and arrival timing and estimated survival to Lower Granite Dam. Principal results from tagging and interrogation during 2007-2008 are listed below: (1) In July and August 2007, we PIT tagged and released 7,390 wild Chinook salmon parr in 12 Idaho streams or sample areas. (2) Overall observed mortality from collection, handling, tagging, and after a 24-hour holding period was 1.4%. (3) Of the 2,524 Chinook salmon parr PIT tagged and released in Valley Creek in summer 2007, 218 (8.6%) were detected at two instream PIT-tag monitoring systems in lower Valley Creek from late summer 2007 to the following spring 2008. Of these, 71.6% were detected in late summer/fall, 11.9% in winter, and 16.5% in spring. Estimated parr-to-smolt survival to Lower Granite Dam was 15.5% for the late summer/fall group, 48.0% for the winter group, and 58.5% for the spring group. Based on detections at downstream dams, the overall efficiency of VC1 (upper) or VC2 (lower) Valley Creek monitors for detecting these fish was 21.1%. Using this VC1 or VC2 efficiency, an estimated 40.8% of all summer-tagged parr survived to move out of Valley Creek, and their estimated survival from that point to Lower Granite Dam was 26.5%. Overall estimated parr-to-smolt survival for all summer-tagged parr from this stream at the dam was 12.1%. Development and improvement of instream PIT-tag monitoring systems continued throughout 2007 and 2008. (4) Testing of PIT-tag antennas in lower Big Creek during

  13. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2005-2006 Annual Report.

    SciTech Connect

    Smith, Steven G.; Muir, William D.; Marsh, Douglas M.

    2006-05-01

    In 2005, the National Marine Fisheries Service and the University of Washington completed the thirteenth year of a study to estimate survival and travel time of juvenile salmonids Oncorhynchus spp. passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder tags (PIT tags). We PIT tagged and released a total of 18,439 hatchery steelhead, 5,315 wild steelhead, and 6,964 wild yearling Chinook salmon at Lower Granite Dam in the Snake River. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and at sites within the hydropower system in both the Snake and Columbia Rivers. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, Ice Harbor, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the ''single-release model''). Primary research objectives in 2005 were: (1) Estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon O. tshawytscha and steelhead O. mykiss. (2) Evaluate relationships between survival estimates and migration conditions. (3) Evaluate the survival estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2005 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Additional details on the methodology and statistical models used are provided in previous reports cited here.

  14. An Integrated Sediment Budget for the Le Sueur River in Southern Minnesota

    NASA Astrophysics Data System (ADS)

    Day, S. S.; Belmont, P.; Perg, L.; Johnson, A.; Gran, K.; Jennings, C.; Wilcock, P.

    2007-12-01

    The Le Sueur River is the primary sediment contributor to the Minnesota River, which is impaired by sediment under the Clean Water Act. The necessary first step toward developing a watershed management plan is identifying sediment sources and sinks throughout the basin. The focus of this study is to quantify the contribution of sediment from different sources in order to understand the broader problems affecting the larger Minnesota Basin. The lower Le Sueur River is actively incising in response to late Pleistocene baselevel fall on the Minnesota River, a result of the catastrophic draining of glacial Lake Agassiz. Potential sediment sources along the Le Sueur include high bluffs composed of highly consolidated Pre-Illinoisian, Illinoisian and Wisconsinin till and alluvial sediment, growing ravines and gullies, sediment exchange between the active channel and floodplains, as well as upland agricultural fields, which account for over 90% of the land surface. We applied side-scanning LiDAR to quantify the amount of sediment being eroded from the high bluffs and banks. To understand meander migration rates as well as ravine and gully retreat rates, and to supplement the understanding of bluff retreat rates, we have used aerial LiDAR along with comparative analysis of historic aerial orthophotos. The aerial LiDAR will also be used to calculate the volume of sediment being stored in the floodplains and terraces along the river, which will be used to create a floodplain exchange model. Preliminary results indicate that bluff retreat rates could be as high as 0.4 meters per year and meander bend migration rates up to 3 meters per year in isolated reaches of the watershed. Data collected from each potential source will be combined to create an overall sediment routing model for the watershed.

  15. Meandered-line antenna with integrated high-impedance surface.

    SciTech Connect

    Forman, Michael A.

    2010-09-01

    A reduced-volume antenna composed of a meandered-line dipole antenna over a finite-width, high-impedance surface is presented. The structure is novel in that the high-impedance surface is implemented with four Sievenpiper via-mushroom unit cells, whose area is optimized to match the meandered-line dipole antenna. The result is an antenna similar in performance to patch antenna but one fourth the area that can be deployed directly on the surface of a conductor. Simulations demonstrate a 3.5 cm ({lambda}/4) square antenna with a bandwidth of 4% and a gain of 4.8 dBi at 2.5 GHz.

  16. Comparison of migration rate and survival between radio-tagged and PIT-tagged migrant yearling chinook salmon in the Snake and Columbia rivers

    USGS Publications Warehouse

    Hockersmith, E.E.; Muir, W.D.; Smith, S.G.; Sandford, B.P.; Perry, R.W.; Adams, N.S.; Rondorf, D.W.

    2003-01-01

    A study was conducted to compare the travel times, detection probabilities, and survival of migrant hatchery-reared yearling chinook salmon Oncorhynchus tshawytscha tagged with either gastrically or surgically implanted sham radio tags (with an imbedded passive integrated transponder [PIT] tag) with those of their cohorts tagged only with PIT tags in the Snake and Columbia rivers. Juvenile chinook salmon with gastrically implanted radio tags migrated significantly faster than either surgically radio-tagged or PIT-tagged fish, while migration rates were similar among surgically radio-tagged and PIT-tagged fish. The probabilities of PIT tag detection at downstream dams varied by less than 5% and were not significantly different among the three groups. Survival was similar among treatments for median travel times of less than approximately 6 d (migration distance of 106 km). However, for both gastrically and surgically radio-tagged fish, survival was significantly less than for PIT-tagged fish, for which median travel times exceeded approximately 10 d (migration distance of 225 km). The results of this study support the use of radio tags to estimate the survival of juvenile chinook salmon having a median fork length of approximately 150 mm (range, 127-285 mm) and a median travel time of migration of less than approximately 6 d.

  17. Molecular Detection of Campylobacter spp. and Fecal Indicator Bacteria during the Northern Migration of Sandhill Cranes (Grus canadensis) at the Central Platte River

    PubMed Central

    Ryu, Hodon; Vogel, Jason; Santo Domingo, Jorge; Ashbolt, Nicholas J.

    2013-01-01

    The risk to human health of the annual sandhill crane (Grus canadensis) migration through Nebraska, which is thought to be a major source of fecal pollution of the central Platte River, is unknown. To better understand potential risks, the presence of Campylobacter species and three fecal indicator bacterial groups (Enterococcus spp., Escherichia coli, and Bacteroidetes) was assayed by PCR from crane excreta and water samples collected during their stopover at the Platte River, Nebraska, in 2010. Genus-specific PCR assays and sequence analyses identified Campylobacter jejuni as the predominant Campylobacter species in sandhill crane excreta. Campylobacter spp. were detected in 48% of crane excreta, 24% of water samples, and 11% of sediment samples. The estimated densities of Enterococcus spp. were highest in excreta samples (mean, 4.6 × 108 cell equivalents [CE]/g), while water samples contained higher levels of Bacteroidetes (mean, 5.1 × 105 CE/100 ml). Enterococcus spp., E. coli, and Campylobacter spp. were significantly increased in river water and sediments during the crane migration period, with Enterococcus sp. densities (∼3.3 × 105 CE/g) 2 to 4 orders of magnitude higher than those of Bacteroidetes (4.9 × 103 CE/g), E. coli (2.2 × 103 CE/g), and Campylobacter spp. (37 CE/g). Sequencing data for the 16S rRNA gene and Campylobacter species-specific PCR assays indicated that C. jejuni was the major Campylobacter species present in water, sediments, and crane excreta. Overall, migration appeared to result in a significant, but temporary, change in water quality in spring, when there may be a C. jejuni health hazard associated with water and crops visited by the migrating birds. PMID:23584775

  18. Wind turbine wake meandering at the laboratory and field scales

    NASA Astrophysics Data System (ADS)

    Heisel, Michael; Musa, Mirko; Hong, Jiarong; Guala, Michele

    2016-11-01

    Flow measurements were collected in the wake of the utility-scale (2.5MW) Eolos wind turbine using a ground-based light detection and ranging (LiDAR) wind profiler to identify the characteristics of wake meandering at the field scale. The investigation seeks to establish the influence of scale and atmospheric turbulence on wake meandering, which has been observed to leave a strong spectral signature on laboratory measurements in wind tunnel and channel flows. The experimental data include multiple test periods at various downstream distances within the turbine wake. Inflow conditions were assessed using a meteorological tower equipped with sonic anemometers. Additionally, an experiment was conducted in the Saint Anthony Falls Laboratory atmospheric boundary layer wind tunnel to provide a direct comparison for the utility-scale results and to reaffirm the findings of previous laboratory-scale investigations. Estimates of the wake and inflow one-dimensional velocity spectra were compared to determine whether wake meandering characteristics are present at both scales. An empirical correction to the velocity spectra of the LiDAR and a few options to extract a more local velocity signal are discussed to compensate for the inherent limitations of LiDAR in capturing turbulent fluctuations.

  19. Survival Estimates for the Passage of Spring-Migrating Juvenile Salmonids through Snake and Columbia River Dams and Reservoirs, 2001-2002 Annual Report.

    SciTech Connect

    Zabel, Richard; Williams, John G.; Smith, Steven G.

    2002-06-01

    In 2001, the National Marine Fisheries Service and the University of Washington completed the ninth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from passive integrated transponder (PIT)-tagged fish. We PIT tagged and released at Lower Granite Dam a total of 17,028 hatchery and 3,550 wild steelhead. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream of the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using the Single-Release Model. Primary research objectives in 2001 were to: (1) estimate reach and project survival and travel time in the Snake and Columbia Rivers throughout the yearling chinook salmon and steelhead migrations; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2001 for PIT-tagged yearling chinook salmon and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures with a minimum of text. More details on methodology and statistical models used are provided in previous reports cited in the text. Results for summer-migrating chinook salmon will be reported separately.

  20. Pair-Trawl Detection of PIT-Tagged Juvenile Salmonids Migrating in the Columbia River Estuary, 2008 Report of Research.

    SciTech Connect

    Magie, Robert J.; Morris, Matthew S.; Ledgerwood, Richard D.

    2009-06-03

    In 2008, we sampled migrating juvenile Pacific salmonids Oncorhynchus spp. tagged with passive integrated transponder (PIT) tags using a surface pair trawl in the upper Columbia River estuary (rkm 61-83). The cod-end of the trawl was replaced with a cylindrical PIT-tag detection antenna with an 86-cm-diameter fish-passage opening and two detection coils connected in series. The pair trawl was 105 m long with a 91.5-m opening between the wings and a sample depth of 4.9 m. Also during 2008, we finalized the development of a prototype 'matrix' antenna, which was larger than previous antennas by a considerable magnitude. The matrix antenna consisted of 6 coils: a 3-coil front component and a 3-coil rear component, which were separated by 1.5-m of net mesh. The fish-passage opening was 2.5 m wide by 3.0 m tall and was attached to a standard-size pair trawl net. Intermittent sampling with a single crew began on 7 March and targeted yearling Chinook salmon O. tshawytscha and steelhead O. mykiss. Daily sampling using two crews began on 30 April and continued through 14 June; during this period we detected 2.7% of all juvenile salmonids previously detected at Bonneville Dam--a measure of sample efficiency. Sampling with a single crew continued through 20 August and targeted subyearling Chinook salmon. We detected 7,397 yearling Chinook salmon, 2,735 subyearling Chinook salmon, 291 coho salmon O. kisutch, 5,950 steelhead, and 122 sockeye salmon O. nerka in the upper estuary. We deployed the matrix antenna system and the older, cylindrical antenna system (86-cm-diameter fish-passage opening) simultaneously in mid-May 2008 to test matrix detection efficiency. The cylindrical antenna system had been used successfully in 2007 and early 2008. Because distribution of migrating salmonids in the estuary changes rapidly, we felt that a tandem sampling effort between the two systems was the only way to truly evaluate comparative detection efficiency. We deployed both systems within 1

  1. Evaluation of energy expenditure in adult spring Chinook salmon migrating upstream in the Columbia River Basin: an assessment based on sequential proximate analysis

    USGS Publications Warehouse

    Mesa, M.G.; Magie, C.D.

    2006-01-01

    The upstream migration of adult anadromous salmonids in the Columbia River Basin (CRB) has been dramatically altered and fish may be experiencing energetically costly delays at dams. To explore this notion, we estimated the energetic costs of migration and reproduction of Yakima River-bound spring Chinook salmon Oncorhynchus tshawytscha using a sequential analysis of their proximate composition (i.e., percent water, fat, protein, and ash). Tissues (muscle, viscera, and gonad) were sampled from fish near the start of their migration (Bonneville Dam), at a mid point (Roza Dam, 510 km upstream from Bonneville Dam) and from fresh carcasses on the spawning grounds (about 100 km above Roza Dam). At Bonneville Dam, the energy reserves of these fish were remarkably high, primarily due to the high percentage of fat in the muscle (18-20%; energy content over 11 kJ g-1). The median travel time for fish from Bonneville to Roza Dam was 27 d and ranged from 18 to 42 d. Fish lost from 6 to 17% of their energy density in muscle, depending on travel time. On average, fish taking a relatively long time for migration between dams used from 5 to 8% more energy from the muscle than faster fish. From the time they passed Bonneville Dam to death, these fish, depending on gender, used 95-99% of their muscle and 73-86% of their viscera lipid stores. Also, both sexes used about 32% of their muscular and very little of their visceral protein stores. However, we were unable to relate energy use and reproductive success to migration history. Our results suggest a possible influence of the CRB hydroelectric system on adult salmonid energetics.

  2. Assessing geomorphic sensitivity in relation to river capacity for adjustment

    NASA Astrophysics Data System (ADS)

    Reid, H. E.; Brierley, G. J.

    2015-12-01

    River sensitivity describes the nature and rate of channel adjustments. An approach to analysis of geomorphic river sensitivity outlined in this paper relates potential sensitivity based on the expected capacity of adjustment for a river type to the recent history of channel adjustment. This approach was trialled to assess low, moderate and high geomorphic sensitivity for four different types of river (10 reaches in total) along the Lower Tongariro River, North Island, New Zealand. Building upon the River Styles framework, river types were differentiated based upon valley setting (width and confinement), channel planform, geomorphic unit assemblages and bed material size. From this, the behavioural regime and potential for adjustment (type and extent) were determined. Historical maps and aerial photographs were geo-rectified and the channel planform digitised to assess channel adjustments for each reach from 1928 to 2007. Floodplain width controlled by terraces, exerted a strong influence upon reach scale sensitivity for the partly-confined, wandering, cobble-bed river. Although forced boundaries occur infrequently, the width of the active channel zone is constrained. An unconfined braided river reach directly downstream of the terrace-confined section was the most geomorphically sensitive reach. The channel in this reach adjusted recurrently to sediment inputs that were flushed through more confined, better connected upstream reaches. A meandering, sand-bed river in downstream reaches has exhibited negligible rates of channel migration. However, channel narrowing in this reach and the associated delta indicate that the system is approaching a threshold condition, beyond which channel avulsion is likely to occur. As this would trigger more rapid migration, this reach is considered to be more geomorphically sensitive than analysis of its low migration rate alone would indicate. This demonstrates how sensitivity is fashioned both by the behavioural regime of a reach

  3. Two-Dimensional Depth-Averaged Hydrodynamic Model for Meandering Channels

    NASA Astrophysics Data System (ADS)

    Yu, C.; Duan, J. G.

    2013-12-01

    This research is to simulate meandering channel processes using a two-dimensional depth-averaged hydrodynamic model. The complex interactions among unsteady flow, turbulence, secondary flow, sediment transport and bank erosion are simulated in the model. The governing equations are the two-dimensional depth-averaged Reynolds-averaged Navier-Stokes (2D-RANS) equations and the Exner equation for bed elevation changes. The k-ɛ turbulence model is coupled into the governing equations to calculate the Reynolds stresses in terms of the eddy viscosity concept. The effect of secondary flow, which represents the discrepancy between depth-averaged velocity and actual velocity, is expressed as the dispersion terms in momentum equations. Non-equilibrium sediment transport algorithm is adapted which accounts for the spatial lag between the instantaneous flow properties and the rate of sediment transport. During the process of adaptation, the sediment transport rate gradually develops into the transport capacity of a given flow condition. The model adopts the nonequilibrium total load sediment transport equation that uses the adaptation length to calculate the actual rate of sediment transport. The evolution of channel bed and bank is modeled by the general Exner equation which accounts for both vertical deformation of bed elevation as well as lateral migration of bank. The system of governing equations is solved by the Godunov-type finite volume method on a rectangular grid. The Harten-Lax-van Leer-Contact (HLLC) approximate Riemann solver is adapted to this system of seven equations and the advective fluxes across each cell interface are simultaneously calculated by the extended HLLC solver. At each time step, the diffusion terms in the governing equations are solved by the implicit Euler scheme which is more stable than explicit scheme for the diffusion terms. The source terms are discretized in a well-balanced way to retain the C-property of the proposed hydrodynamic model

  4. A field reciprocal transplant experiment reveals asymmetric costs of migration between lake and river ecotypes of three-spined sticklebacks (Gasterosteus aculeatus).

    PubMed

    Kaufmann, Joshka; Lenz, Tobias L; Kalbe, Martin; Milinski, Manfred; Eizaguirre, Christophe

    2017-02-17

    Theory of local adaptation predicts that non-adapted migrants will suffer increased costs compared to local residents. Ultimately this process can result in the reduction of gene flow and culminate in speciation. Here, we experimentally investigated the relative fitness of migrants in foreign habitats, focusing on diverging lake and river ecotypes of three-spined sticklebacks. A reciprocal transplant experiment performed in the field revealed asymmetric costs of migration: while mortality of river fish was increased under lake conditions, lake migrants suffered from reduced growth relative to river residents. Selection against migrants thus involved different traits in each habitat but generally contributed to bidirectional reduction in gene flow. Focusing particularly on the parasitic environments, migrant fish differed from resident fish in the parasite community they harboured. This pattern correlated with both cellular phenotypes of innate immunity as well as with allelic variation at the genes of the major histocompatibility complex. In addition to showing the costs of migration in three-spined sticklebacks, this study highlights the role of asymmetric selection particularly from parasitism in genotype sorting and in the emergence of local adaptation. This article is protected by copyright. All rights reserved.

  5. Migrational Characteristics, Biological Observations, and Relative Survival of Juvenile Salmonids Entering the Columbia River Estuary, 1966-1983, 1985 Final Report of Research.

    SciTech Connect

    Dawley, Earl M.

    1986-04-01

    Natural runs of salmonids in the Columbia River basin have decreased as a result of hydroelectric-dam development, poor land- and forest-management, and over-fishing. This has necessitated increased salmon culture to assure adequate numbers of returning adults. Hatchery procedures and facilities are continually being modified to improve both the efficiency of production and the quality of juveniles produced. Initial efforts to evaluate changes in hatchery procedures were dependent upon adult contributions to the fishery and returns to the hatchery. Procedures were developed for sampling juvenile salmon and steelhead entering the Columbia River estuary and ocean plume. The sampling of hatchery fish at the terminus of their freshwater migration assisted in evaluating hatchery production techniques and identifying migrational or behavioral characteristics that influence survival to and through the estuary. The sampling program attempted to estimate survival of different stocks and define various aspects of migratory behavior in a large river, with flows during the spring freshet from 4 to 17 thousand cubic meters per second (m/sup 3//second).

  6. Hydrological and sedimentological variability of the peri-fluvial wetlands of the middle Loire river (France)

    NASA Astrophysics Data System (ADS)

    Gautier, E.; Kunesch, S.; Negrel, P.; Petelet-Giraud, E.

    2003-04-01

    With a catchment basin of 112,120 km^2 and a length of 1012 km, the Loire River is one of the most important fluvial hydrosystems in France. Notwithstanding numerous modifications (dikes, dams, nuclear power plants, gravel extractions), the Loire River hydrology has been saved from a total regularisation. Therefore, the spatial diversity of fluvial landforms creates a patchwork of wetlands: ox-bow lakes, dewatered channels... As one aim of this work was to determine the hydrological and sedimentological processes in the various wetlands, in a context of spatial variability of the fluvial landforms, we used a pluridisciplinarity approach: geomorphology, hydrology, geochemistry. The present study has targeted the functioning between the various hydro-geomorphologic units of the floodplain (main and secondary active channels, abandoned branches and the riverbank [alluvial] and perched aquifers), with regard to the spatial heterogeneity of the different fluxes and the temporal variations of bottom water level, full-bank stage and overflow discharge. In the upper part of the study area, mobile meanders prevail. The meanders migration results in oxbow lakes and the connection between the lakes and the other water reservoirs (e.g. river- and groundwaters) induce a strong lateral variability and a time delayed water input by the river as evidenced by the different geochemical and isotopic signatures. Downstream, the Loire River develops a multiple-channels pattern, of which numerous are abandoned. They are often dewatered along the year, only reconnected to the main channel during the periods of overflow discharges and the influence of the Loire riverwater is progressively substituted by the input of groundwaters (alluvial and perched aquifers). It appears that the submersion duration and the type of connection between the wetlands and the various reservoirs (inlet or outlet connection with the river, connection with the aquifers.) strongly influence the sedimentation rate

  7. Stream water bypass through a meander neck, laterally extending the hyporheic zone

    NASA Astrophysics Data System (ADS)

    Peterson, Eric W.; Sickbert, Timothy B.

    2006-12-01

    A meander lobe neck diverts stream water into a hyporheic flow path adjacent to a low gradient stream, Little Kickapoo Creek, Illinois, USA. Hyporheic processes have been well-documented in surface water-groundwater mixing zones underlying and directly adjacent to streams. Alluvial aquifers underlying meander necks provide a further extension of the hyporheic zone. Hydraulic head and temperature data, collected from a set of wells across a meander neck, show stream water moves through the meander neck. The hydraulic gradient across the meander neck (0.006) is greater than the stream gradient (0.003) between the same points, driving the bypass. Rapid subsurface response to elevated stream stage shows a hydraulic connection between the stream and the alluvial aquifer. Temperature data and a Peclet number (Pe) of 43.1 indicate that thermal transport is dominated by advection from the upstream side to the downstream side of the meander neck. The temperature observed within the alluvial aquifer correlates with seasonal temperature variation. Together, the pressure and temperature data indicate that water moves across the meander neck. The inflow of stream water through the meander neck suggests that the meander system may host biogeochemical hyporheic zone processes.

  8. Ecogeomorphic feedbacks and flood loss of riparian tree seedlings in meandering channel experiments

    NASA Astrophysics Data System (ADS)

    Kui, Li; Stella, John C.; Lightbody, Anne; Wilcox, Andrew C.

    2014-12-01

    During floods, fluvial forces interact with riparian plants to influence evolution of river morphology and floodplain plant community development. Understanding of these interactions, however, is constrained by insufficient precision and control of drivers in field settings, and insufficient realism in laboratory studies. We completed a novel set of flume experiments using woody seedlings planted on a sandbar within an outdoor meandering stream channel. We quantified effects on local sedimentation and seedling loss to scour and burial across realistic ranges of woody plant morphologies (Populus versus Tamarix species), densities (240 plants m-2 versus 24 m-2), and sediment supply (equilibrium versus deficit). Sedimentation was higher within Tamarix patches than Populus patches, reflecting Tamarix's greater crown frontal area and lower maximum crown density. Plant dislodgement occurred rarely (1% of plants) and was induced in plants with shorter roots. Complete burial was most frequent for small Tamarix that occurred at high densities. Burial risk decreased 3% for Populus and 13% for Tamarix for every centimeter increment in stem height, and was very low for plants >50 cm tall. These results suggest that Tamarix are proportionally more vulnerable than Populus when small (<20 cm tall), but that larger plants of both species are resistant to both burial and scour. Thus, plant morphological traits and development windows must be considered in addition to physical drivers when designing process-based restoration efforts on regulated rivers such as flow releases to benefit native tree species.

  9. Seasonal movements among river reaches, migration strategies, and population structure of the divided Connecticut River shortnose sturgeon population: the effects of Holyoke Dam

    USGS Publications Warehouse

    Kynard, Boyd; Kieffer, Micah; Vinogradov, Phil; Kynard, B.; Bronzi, P.; Rosenthal, H.

    2012-01-01

    Even after 155 years, each population segment seasonally migrates toward the other attempting to maintain the natural connection. Migration timing and style of pre-spawning and post-spawning males and females is discussed, as is homing. The impact of Holyoke Dam on population size and growth is characterized and turbine mortality of adult sturgeon passing through a Kaplan turbine at the dam is estimated. The chapter also identifies a behavioral dysfunction that results when migrations are blocked by a dam and are not completed at the correct stage of life. Many unknown effects of damming on other long-lived riverine fishes are likely captured in this 16-year study.

  10. Instream Flows Needed for Successful Migration and Rearing of Rainbow and Westslope Cutthroat Trout in Selected Tributaries of the Kootenai River: Final Report FY 1988.

    SciTech Connect

    Marotz, Brian

    1988-06-01

    This is the second phase of a two-part study that was conducted by Montana Department of Fish, Wildlife and Parks in contractual agreement with Bonneville Power Administration to address measures of the Northwest Power Planning Council's River Basin Fish and Wildlife Program. Objectives were to determine instream flow needs in Kootenai River tributaries to maintain successful fish migration, spawning and rearing habitat of game fish, evaluate existing resident and rearing fish populations, and compile hydrologic and fishery information required to secure legal reservation of water for the fishery source. The Kootenai River fishery is threatened by microhydro and other water use development which reduce tributary habitat critical for maintaining a healthy spawning and rearing environment. The wetted perimeter method was used to estimate flows required to maintain existing resident and migratory fish populations in 28 tributaries to the Kootenai River. Migrant passage flows were determined using the discharge-average depth relationship at four (usually five) riffle transects. This information will provide the basis to reserve water through application to the Montana Department of Natural Resources and Conservation. 45 figs., 56 tabs.

  11. Ocean-Atmosphere Interaction Over Agulhas Extension Meanders

    NASA Technical Reports Server (NTRS)

    Liu, W. Timothy; Xie, Xiaosu; Niiler, Pearn P.

    2007-01-01

    Many years of high-resolution measurements by a number of space-based sensors and from Lagrangian drifters became available recently and are used to examine the persistent atmospheric imprints of the semi-permanent meanders of the Agulhas Extension Current (AEC), where strong surface current and temperature gradients are found. The sea surface temperature (SST) measured by the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and the chlorophyll concentration measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) support the identification of the meanders and related ocean circulation by the drifters. The collocation of high and low magnitudes of equivalent neutral wind (ENW) measured by Quick Scatterometer (QuikSCAT), which is uniquely related to surface stress by definition, illustrates not only the stability dependence of turbulent mixing but also the unique stress measuring capability of the scatterometer. The observed rotation of ENW in opposition to the rotation of the surface current clearly demonstrates that the scatterometer measures stress rather than winds. The clear differences between the distributions of wind and stress and the possible inadequacy of turbulent parameterization affirm the need of surface stress vector measurements, which were not available before the scatterometers. The opposite sign of the stress vorticity to current vorticity implies that the atmosphere spins down the current rotation through momentum transport. Coincident high SST and ENW over the southern extension of the meander enhance evaporation and latent heat flux, which cools the ocean. The atmosphere is found to provide negative feedback to ocean current and temperature gradients. Distribution of ENW convergence implies ascending motion on the downwind side of local SST maxima and descending air on the upwind side and acceleration of surface wind stress over warm water (deceleration over cool water); the convection may escalate the contrast of

  12. Flow, Morphology and Sedimentology of an Evolving Chute Cutoff on the Wabash River, IL-in.

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Best, J.; Rhoads, B. L.; Larson, T. H.

    2014-12-01

    The development of chute cutoffs and the resulting abandonment of meander bends have a substantial influence on the sedimentary dynamics of floodplains. The incision of a chute cutoff channel can rapidly mobilize a large volume of floodplain sediment. On the other hand, bar formation during bend abandonment and the subsequent deposition of sediment within the oxbow lake are key processes in the production of a heterogeneous floodplain sedimentary architecture. This paper describes the evolution of two recent chute cutoffs on the Wabash River, IL-IN. We follow these cutoffs from their initial incision in 2008-2009 through the early stages of bend abandonment. The volume of floodplain sediment mobilized by erosion of the two cutoff channels is estimated using channel bankline positions determined from RTK-GPS surveys and aerial orthophotographs; this flux is then assessed within the context of the sediment mobilized by lateral migration of bends. Repeat bathymetric surveys and aerial photography capture the evolution of bar forms associated with the chute cutoff, and data from ground-penetrating radar reveal the subsurface structure of the complex assemblage of bars that developed as the chute cutoff system shifted from a predominantly erosional to a mixed depositional-erosional phase. These results are combined with knowledge of chute cutoff hydrodynamics to develop an understanding of the dynamics of sediment exchange between river channels and floodplains at evolving meander bend cutoffs.

  13. Effects of Iron Gate Dam discharge and other factors on the survival and migration of juvenile coho salmon in the lower Klamath River, northern California, 2006-09

    USGS Publications Warehouse

    Beeman, John; Juhnke, Steven; Stutzer, Greg; Wright, Katrina

    2012-01-01

    Current management of the Klamath River includes prescribed minimum discharges intended partly to increase survival of juvenile coho salmon during their seaward migration in the spring. To determine if fish survival was related to river discharge, we estimated apparent survival and migration rates of yearling coho salmon in the Klamath River downstream of Iron Gate Dam. The primary goals were to determine if discharge at Iron Gate Dam affected coho salmon survival and if results from hatchery fish could be used as a surrogate for the limited supply of wild fish. Fish from hatchery and wild origins that had been surgically implanted with radio transmitters were released into the Klamath River slightly downstream of Iron Gate Dam at river kilometer 309. Tagged fish were used to estimate apparent survival between, and passage rates at, a series of detection sites as far downstream as river kilometer 33. Conclusions were based primarily on data from hatchery fish, because wild fish were only available in 2 of the 4 years of study. Based on an information-theoretic approach, apparent survival of hatchery and wild fish was similar, despite differences in passage rates and timing, and was lowest in the 54 kilometer (km) reach between release and the Scott River. Models representing the hypothesis that a short-term tagging- or handling-related mortality occurred following release were moderately supported by data from wild fish and weakly supported by data from hatchery fish. Estimates of apparent survival of hatchery fish through the 276 km study area ranged from 0.412 (standard error [SE] 0.048) to 0.648 (SE 0.070), depending on the year, and represented an average of 0.790 per 100 km traveled. Estimates of apparent survival of wild fish through the study area were 0.645 (SE 0.058) in 2006 and 0.630 (SE 0.059) in 2009 and were nearly identical to the results from hatchery fish released on the same dates. The data and models examined supported positive effects of water

  14. Upstream migration of two pre-spawning shortnose sturgeon passed upstream of Pinopolis Dam, Cooper River, South Carolina

    USGS Publications Warehouse

    Finney, S.T.; Isely, J.J.; Cooke, D.W.

    2006-01-01

    Two shortnose sturgeon were artificially passed above the Pinopolis Lock and Dam into the Santee-Cooper Lakes in order to simulate the use of a fish-passage mechanism. Movement patterns and spawning behavior were studied to determine the potential success of future shortnose sturgeon migrations if and when a fish-migration bypass structure is installed. In addition to movement patterns, water temperature was monitored in areas that shortnose sturgeons utilized. Shortnose sturgeon migrated through a large static system to a known shortnose sturgeon spawning area more than 160 km upstream where water temperatures were consistent with known shortnose sturgeon spawning temperatures. No specific movement patterns in the reservoir system were recorded during downstream migrations.

  15. Developmental analysis of the external granular layer in the meander tail mutant mouse: do cerebellar microneurons have independent progenitors?

    PubMed

    Napieralski, J A; Eisenman, L M

    1993-08-01

    The cerebellum of the meander tail mutant mouse (mea/mea) is characterized by an apparently normal cytoarchitecture posteriorly with an abrupt transition to an abnormal anterior region. Anteriorly, there is abnormal foliation, a drastic reduction in the granule cells (GC) population, disorganization of the Purkinje cells (PC), and a virtual absence of Bergmann glial processes. In this paper we analyze the prenatal and postnatal development of the cerebellum in the mea/mea and attempt to determine the phenotypic onset of the mutation in the anterior region. Hematoxylin and eosin stained sections reveal a morphological difference in the cerebellum of the mea/mea as early as embryonic day 16 characterized by a reduction in the external granule cell layer (EGL). The reduction in the EGL becomes increasingly apparent as development proceeds. This deficit in the EGL most probably results in the absence of GC, but it is unclear at this point whether reduced migration, proliferation, and/or increased cell death is the major factor. Interestingly, immunohistochemical staining with a monoclonal antibody against parvalbumin reveals that the basket and stellate cells, which are also thought to arise from the EGL, are present in the anterior region of the mea/mea cerebellum. These results suggest that the lack of GC in the meander tail is due to an early expressed abnormality of the EGL. However, the presence of the basket and/or stellate cells raises some interesting questions concerning the lineage of the cerebellar microneurons.

  16. Interaction of Hydraulic and Geotechnical Processes, and Sediment Transport in Controlling Channel Morphology in an Active Meander Bend

    NASA Astrophysics Data System (ADS)

    Simon, A.; Kuhnle, R.

    2004-12-01

    Evolution of meanders in incised alluvial channels is controlled by interactions between hydraulic forces acting on the bed and bank toe, and gravitational forces acting on in situ bank material. Vertical and lateral accretion of point bars lead to re-direction of flows in a downvalley direction that impinge on bank-toe surfaces causing undercutting, steepening and ultimate failure of the bank mass by gravity. The processes and forms inherent in incised meanders have been studied at an actively evolving meander bend on Goodwin Creek, Mississippi since 1996. Periodic surveys dating from 1977 to 1996 coupled with the dating of woody vegetation growing on the channel banks and bars were used to determine a migration rate of about 0.5 m/y since the mid-1960s. Up to 28 repetitive surveys were conducted at each of 10 monumented cross sections between 1996 and 2003 over an 82 m-long reach. Over the seven years of monitoring, 894 m3 of bank materials have been eroded from the reach while 436 m3 of sediment have been deposited on the bed and bar. Mean annual sediment concentrations have been essentially stable since the percent of cultivated land in the basin stabilized in the early 1990s. Migration of the outside bend by mass-wasting and toe removal of failed material has been matched by commensurate lateral accretion of point bars. Existing point bars grow vertically at a rate of about 5 cm/yr and now support establishing woody vegetation. Aggradation on the channel bed and lateral channel migration by bar accretion and opposite-bank retreat results in net erosion of all sediment but a net deposition of hydraulically-controlled sands and gravels. The erosion represents series of bank-failure episodes with subsequent removal of failed material by stormflow. A direct correlation between volumes of bar accretion and opposite-side bank erosion was developed, thus establishing a link between hydraulic and geotechnical processes. Peak-flow water-surface slopes increase with

  17. Survival of Seaward-Migrating PIT and Acoustic-Tagged Juvenile Chinook Salmon in the Snake and Columbia Rivers: An Evaluation of Length-Specific Tagging Effects

    SciTech Connect

    Brown, Richard S.; Oldenburg, Eric W.; Seaburg, Adam; Cook, Katrina V.; Skalski, John R.; Eppard, M. B.; Deters, Katherine A.

    2013-06-12

    Studies examining the survival of juvenile salmon as they emigrate to the ocean provide important information regarding the management of regulated river systems. Acoustic telemetry is a widely used tool for evaluating the behavior and survival of juvenile salmonids in the Columbia River basin. Thus, it is important to understand how the surgical tagging process and the presence of a transmitter affect survival so any biases can be accounted for or eliminated. This study evaluated the effects of fish length and tag type on the survival of yearling and subyearling Chinook salmon during their seaward migrations through the Snake and Columbia rivers during 2006, 2007, and 2008. Fish were collected at Lower Granite Dam on the Snake River (river kilometer 695) and implanted with either only a passive integrated transponder (PIT) tag (PIT fish) or both a PIT tag and an acoustic transmitter (AT fish). Survival was estimated from release at Lower Granite Dam to multiple downstream locations (dams) using the Cormack–Jolly–Seber single release model, and analysis of variance was used to test for differences among length-classes and between tag types. No length-specific tag effect was detected between PIT and AT fish (i.e., length affected the survival of PIT fish in a manner similar to which it affected the survival of AT fish). Survival among the smallest length class (i.e., 80–89 mm) of both PIT and AT subyearling Chinook salmon was markedly low (i.e., 4%). Fish length was positively correlated with the survival of both PIT and AT fish. Significant differences in survival were detected between tag types; the survival of PIT fish was generally greater than that of AT fish. However, confounding variables warrant caution in making strong inferences regarding this factor. Further, results suggest that tag effects may be due to the process of surgically implanting the transmitter rather than the presence of the transmitter.

  18. Interpretation of Measured Tracer Concentration Fluctuations Using a Sinusoidal Meandering Plume Model.

    NASA Astrophysics Data System (ADS)

    Peterson, Holly; Lamb, Brian; Stock, David

    1990-12-01

    Simultaneous instantaneous concentration and wind velocity fluctuations were measured 100 to 752 m downwind of a point source release of SF6 tracer during two field studies conducted amid rolling wheat fields and at a flat desert site in eastern Washington. Data from stable, neutron, and unstable conditions are interpreted using a meandering plume model where the meander is defined to be sinusoidal and the instantaneous plume profile is Gaussian. A sensitivity analysis of the model shows that the characteristic concentration time scale is a direct function of the meander time scale and the receptor position relative to the meander centerline. For narrow instantaneous plumes relative to the meander amplitude, the predicted mean crosswind profiles of concentration, intermittency factor, concentration fluctuation intensity, and peak-to-mean ratios exhibit bimodal distributions. Conditional (nonzero) concentration fluctuation intensifies calculated from the model are scattered about 1.0;, the scatter is the result of receptor location, meander amplitude, period, and instantaneous plume width. The magnitude of the scatter from model runs covering different receptor locations is essentially equal to the magnitude of the matter from the tracer observations. The simple meandering plume model thus provides a straightforward explanation of very complex patterns observed in the tracer concentration fluctuation data in terms of wind meander, receptor location, and instantaneous plume width.

  19. Numerical simulation of bar and bank erosion in a vegetated floodplain: A case study in the Otofuke River

    NASA Astrophysics Data System (ADS)

    Iwasaki, Toshiki; Shimizu, Yasuyuki; Kimura, Ichiro

    2016-07-01

    Recent studies suggest that braided river could be single-thread channel by colonization of riparian vegetation; however, this kind of mutual interactions between physical and ecological processes in rivers are still poorly understood. Here we investigate the development of meandering channel in a river, which was originally braided and currently vegetated, the Otofuke River in Japan. The significant morphological processes of this river during a destructive flood event was studied using a two-dimensional morphodynamic model. Using well-calibrated parameters, this model qualitatively reproduced observed morphological changes such as the co-development of sand bars, bar-induced meandering and a chute cutoff. We find that for vegetated channels, meandering could maintain moderate sinuosity; in contrast, in the absence of riparian vegetation, bar-induced meandering channels could become braided. This suggests that distinct meandering channels could be a fundamental channel morphology in the originally braided, but currently vegetated river; however, the simultaneous occurrence of the chute cutoff and meandering indicates that this channel could not be a fully-developed high amplitude meandering channel.

  20. Effect of low-head lock and dam structures on migration and spawning of American shad and striped bass in the Cape Fear River, North Carolina

    USGS Publications Warehouse

    Smith, Joseph A.; Hightower, Joseph E.

    2012-01-01

    Anadromous fish populations within the Cape Fear River, North Carolina, have declined substantially since the late 1800s. Three low-head lock-and-dam (LD) structures on the river (LD-1–3) contributed to this decline by limiting access to upstream spawning habitat. We used egg sampling and sonic telemetry to examine the effects of the LD structures on migration and spawning activity of American shad Alosa sapidissima and striped bassMorone saxatilis. Egg distribution and stage of development suggested that most of the American shad spawning took place downstream from the lowermost structure, LD-1. The predicted mean density of stage-1 American shad eggs at a water temperature of 21°C was 895 eggs/1,000 m3 (95% credible interval [CI] = 800–994) below LD-1; 147 eggs/1,000 m3 (95% CI = 103–197) below LD-2; and 32 eggs/1,000 m3 (95% CI = 17–49) below the uppermost structure, LD-3. The probability of capturing a stage-1 American shad egg was strongly dependent on water temperature and hour of egg collection. Transmitter detections for 20 sonic-tagged American shad and 20 striped bass in 2008 showed that for both species, the majority of fish moved upstream of LD-1; 35% of American shad and 25% of striped bass migrated upstream of LD-3. Based on passage rates at the three LD structures, American shad would be expected to be most abundant downstream of LD-1 and upstream of LD-3. For striped bass, the river section between LD-2 and LD-3 had the highest egg collections and highest predicted proportion of the run. In combination, these results demonstrate that the locking program provides some access to historical spawning habitat, although further improvements in fish passage could benefit both species.

  1. Movement Patterns of American Shad Transported Upstream of Dams on The Roanoke River, North Carolina and Virginia

    USGS Publications Warehouse

    Harris, Julianne E.; Hightower, J.E.

    2011-01-01

    American shad Alosa sapidissima are in decline throughout much of their native range as a result of overfishing, pollution, and habitat alteration in coastal rivers where they spawn. One approach to restoration in regulated rivers is to provide access to historical spawning habitat above dams through a trap-and-transport program. We examined the initial survival, movement patterns, spawning, and downstream passage of sonic-tagged adult American shad transported to reservoir and riverine habitats upstream of hydroelectric dams on the Roanoke River, North Carolina and Virginia, during 2007–2009. Average survival to release in 2007–2008 was 85%, but survival decreased with increasing water temperature. Some tagged fish released in reservoirs migrated upstream to rivers; however, most meandered back and forth within the reservoir. A higher percentage of fish migrated through a smaller (8,215-ha) than a larger (20,234-ha) reservoir, suggesting that the population-level effects of transport may depend on upper basin characteristics. Transported American shad spent little time in upper basin rivers but were there when temperatures were appropriate for spawning. No American shad eggs were collected during weekly plankton sampling in upper basin rivers. The estimated initial survival of sonic-tagged American shad after downstream passage through each dam was 71–100%; however, only 1% of the detected fish migrated downstream through all three dams and many were relocated just upstream of a dam late in the season. Although adult American shad were successfully transported to upstream habitats in the Roanoke River basin, under present conditions transported individuals may have reduced effective fecundity and postspawning survival compared with nontransported fish that spawn in the lower Roanoke River.

  2. Movement and spawning of American shad transported above dams on the Roanoke River, North Carolina and Virginia

    USGS Publications Warehouse

    Harris, Julianne E.; Hightower, Joseph E.

    2011-01-01

    American shad Alosa sapidissima are in decline throughout much of their native range as a result of overfishing, pollution, and habitat alteration in coastal rivers where they spawn. One approach to restoration in regulated rivers is to provide access to historical spawning habitat above dams through a trap-and-transport program. We examined the initial survival, movement patterns, spawning, and downstream passage of sonic-tagged adult American shad transported to reservoir and riverine habitats upstream of hydroelectric dams on the Roanoke River, North Carolina and Virginia, during 2007–2009. Average survival to release in 2007–2008 was 85%, but survival decreased with increasing water temperature. Some tagged fish released in reservoirs migrated upstream to rivers; however, most meandered back and forth within the reservoir. A higher percentage of fish migrated through a smaller (8,215-ha) than a larger (20,234-ha) reservoir, suggesting that the population-level effects of transport may depend on upper basin characteristics. Transported American shad spent little time in upper basin rivers but were there when temperatures were appropriate for spawning. No American shad eggs were collected during weekly plankton sampling in upper basin rivers. The estimated initial survival of sonic-tagged American shad after downstream passage through each dam was 71–100%; however, only 1% of the detected fish migrated downstream through all three dams and many were relocated just upstream of a dam late in the season. Although adult American shad were successfully transported to upstream habitats in the Roanoke River basin, under present conditions transported individuals may have reduced effective fecundity and postspawning survival compared with nontransported fish that spawn in the lower Roanoke River.

  3. Channel change on the Santa Cruz River, Pima County, Arizona, 1936-86

    USGS Publications Warehouse

    Parker, J.T.

    1993-01-01

    The Santa Cruz River, an ephemeral river that drains 8,581 square miles in southeastern Arizona, has a long history of channel instability. Since the late 19th century, lateral channel erosion has caused extensive property damage, particularly in Pima County. During the flood of 1983, about $100 million damage was caused in the Tucson area alone; most damage resulted from bank erosion on the Santa Cruz River and its tributaries. The nature, magni- tude, location, and frequency of channel change on the Santa Cruz River were highly variable in time and space from 1936 through 1986 along a 70-mile reach in Pima County, Arizona. Four mechanisms of lateral channel change--channel migration, avulsion and meander cutoff, channel widening, and arroyo widening--were identified on the Santa Cruz River. The dominant mechanism in a reach depends on channel morphology and flood magnitude. The dominant vertical change has been degradation. The timing and magnitude of channel change at a particular location are controlled primarily by hydroclimatic factors such as magnitude, duration, intensity, and frequency of precipitation and floods. The location of channel change and its magnitude in response to a given discharge are controlled largely by topographic, geologic, hydraulic, and artificial factors. Although much of the present morphology of the Santa Cruz River is the result of recent large floods, a direct link between hydroclimatic con- ditions and channel change is not always evident because resistance of the channel to erosion varies with time. (USGS)

  4. Effect of dietary salt on migration and survival of yearling steelhead produced at Iron Gate Hatchery, Klamath River, 2009

    USGS Publications Warehouse

    Juhnke, S.; Hansel, H.; Wright,; Hetrick,

    2011-01-01

    We surgically implanted radio transmitters into 30 hatchery yearling steelhead (Oncorhynchus mykiss) released from Iron Gate Hatchery during the spring of 2009 to improve our understanding of the effect of dietary salt on their out-migration and survival. Steelhead yearlings were divided into two feed treatments to test the efficacy of a salt-enriched feed in promoting out-migration. Fish were fed either their regular diet (control treatment) or a salt-enriched diet (test treatment) for 38 d prior to their release. We implanted 15 fish of each treatment with radio transmitters for a total of 30 tagged individuals. Nine of the radio-tagged steelhead (four of the control treatment; five of the test treatment) completed their downstream migration to the estuary within the 60-d operational period of the tags. Tagged fish migrated from the hatchery release site to the estuary in an average of 45 d. Neither migration nor survival differed between diet treatments, but small sample size and the relatively short duration of this study limit the conclusiveness of our findings.

  5. Ontogenetic behavior and migration of Dabry's sturgeon, Acipenser dabryanus, from the Yangtze River, with notes on body color and development rate

    USGS Publications Warehouse

    Kynard, B.; Zhuang, P.; Zhang, T.; Zhang, L.

    2003-01-01

    We conducted laboratory experiments with Dabry's sturgeon, Acipenser dabryanus, from the upper Yangtze River to develop a conceptual model of early behavior. We daily observed fish from day-0 (embryo, first life interval after hatching) to day-30 feeding larva for preference of bright habitat and cover, swimming distance above the bottom, up- and down-stream movement, and diel activity. Hatchling to day-12 embryos and days 13-24 larvae were similar for ontogenetic behavior, i.e., neither initiated a dispersal migration, both swam within 15 cm of the bottom, both preferred bright habitat, and neither strongly preferred cover or open habitat. Embryos and larvae were weakly active day and night. Days 72-76 juveniles had a weak nocturnal downstream migration, indicating wild juveniles disperse from a spawning site. In other sturgeon species yet studied representing three genera on three continents, Dabry's sturgeon is the first that does not disperse as an embryo or larva. Development of Dabry's sturgeon is slow, requiring more cumulative temperature degree days per millimeter of larvae TL than is required for other sturgeons to develop into larvae. Thus, a dispersal migration that diverts energy from development may not be adaptive. The available information suggests the initial dispersal of early life intervals is likely done by females, which spawn in a dispersed spawning style, not the usual aggregated spawning style. Juvenile migrants had a black body and tail with a light line along the lateral scutes. The color of juvenile migrants shows that a dark body and tail is characteristic of Acipenser that migrate downstream as larvae or juveniles.

  6. Fluvial Landforms and Landscape Transformations on a Large River Floodplain: Willamette River, Oregon, USA

    NASA Astrophysics Data System (ADS)

    Wallick, R.

    2015-12-01

    Recent detailed mapping of the Willamette River floodplain in northwestern Oregon reveals insights into the floodplain landforms, their formative processes, and historical landscape transformations. Hierarchical mapping classification based mainly upon lidar topography, supplemented by aerial photographs, historical channel and soil maps, and targeted coring of floodplain soils, was carried out for 200 km of the mainstem Willamette River floodplain above Willamette Falls where floodplain landforms mainly reflect fluvial and anthropogenic influences. Stark differences in the character and distribution of floodplain landforms and their underlying stratigraphy give rise to three distinct process regimes along the fluvial portion of the Willamette River. Floodplain surfaces along 60 km of the Upper Willamette River floodplain generally rise 1-2 m above the low-flow water surface and are bisected by complex assemblage of overflow channels and large-amplitude abandoned bends formed by avulsions along this historically multi-thread anastomosing reach. Downstream, the 90 km-long Middle Willamette River between Corvallis and Newburg Pool becomes increasingly entrenched within its floodplain, with floodplains gradually rising up to 8 m above the low flow water surface. These floodplain surfaces are dominated by ridge and swale topography with occasional floodbasins reflecting gradual meander migration and floodplain aggradation. The 50 km-long Newberg Pool is entrenched and confined by Pleistocene Missoula flood deposits and bedrock valley walls. This low-gradient reach extends to the lip of the15-m high Willamette Falls. Historical declines in flood magnitude, bed-material supply, large wood, and bank erodibility result in a more stable modern-day floodplain with narrower active-channel corridor flanked by relict landforms formed by historical flow and sediment regime. Landscape transformations vary across the three process regimes but are greatest along Upper Willamette

  7. Rivers

    USGS Publications Warehouse

    Leopold, Luna Bergere

    1962-01-01

    Rivers are both the means and the routes by which the products of continental weathering are carried to the oceans of the world. Except in the most arid areas more water falls as precipitation than is lost by evaporation and transpiration from the land surface to the atmosphere. Thus there is an excess of water, which must flow to the ocean. Rivers, then, are the routes by which this excess water flows to the ultimate base level. The excess of precipitation over evaporation and transpiration provides the flow of rivers and springs, recharges ground-water storage, and is the supply from which man draws water for his needs.

  8. Tsunami intrusion in wide meandering channels: a Lagrangian numerical experiment

    NASA Astrophysics Data System (ADS)

    Couston, L. A.; Alam, M. R.

    2015-12-01

    Among the many difficulties of tsunami forecast, wave runup on sloped beaches remains a major obstacle in numerical simulations. Traditional Eulerian models must adjust the fluid flow domain continuously due to the moving shorelines, which can significantly affect the computational cost and results accuracy. An efficient though uncommon alternative for accurate runup predictions still exists, consisting in using a Lagrangian model as recently shown by e.g. Couston et al. (2015) who studied the runup of landslide tsunamis in lakes with a non-dispersive Lagrangian model. Here we introduce a fully-nonlinear Boussinesq-type model derived in the Lagrangian framework to investigate various cases of long-wave runup on curved beaches and meandering channels. The governing equations are expressed in terms of curvilinear Lagrangian coordinates, making the model suitable for accurate runup computations at shorelines of arbitrary geometry while retaining the inherent simplicity of a physical model discretized on a fixed and structured grid. We implement an elliptic grid generation algorithm to map the physical space to the computational space, and a high-order finite-difference scheme for time integration. The numerical model has a linear complexity in the number of unknowns when neglecting dispersive effects. We show that the formation of edge waves due to the sloped banks of a wide channel has a significant influence on the capability of a meander or constriction in reflecting the intruding tsunami, and we investigate the effect of dispersion. Reference: Couston, L.-A., Mei, C. C., & Alam, M.-R. (2015). Landslide tsunamis in lakes. Journal of Fluid Mechanics, 772, 784-804.

  9. Developmental analysis of GFAP immunoreactivity in the cerebellum of the meander tail mutant mouse.

    PubMed

    Grishkat, H L; Schwartz, E; Jain, G; Eisenman, L M

    1996-08-01

    It is thought that Bergmann glial fibers assist in the inward migration of granule cells. Model systems in which there is a perturbation of either the migrating cells or the glial cell population have been useful in understanding the migratory process. In the meander tail mutant mouse, the anterior cerebellar region is agranular, whereas the posterior cerebellum is relatively unaffected by the mutation. This study presents a qualitative analysis of the development of cerebellar radial glia in mea/mea and +/mea mice aged from postnatal day 0 to adult, using an antibody against the glia specific antigen, glial fibrillary acidic protein. The results indicate a slight delay in the onset of immunoreactivity in the mea/mea cerebellum and abnormal glial formation in the anterior and posterior regions by postnatal day 5. At postnatal day 11, the full complement of labeled fibers appears to be present and although they appear abnormal in formation, they eventually reach the surface and terminate in oddly shaped and irregularly spaced endfeet. In adult mea/mea and +/mea mice, as compared to the early postnatal stages, there is a significant reduction in GFAP immunoreactive fibers. Cresyl violet stained adult mea/mea sections revealed the presence of ectopic granule cells in radial columns and small clumps at the surface of and within the molecular layer of the caudal cerebellum. Quantitative analyses revealed a 4- to 5-fold increase in the number of ectopic granule cells in lobule VIII of the mea/mea when compared with the +/mea cerebellum. These results suggest that the radial glia in the mea/mea cerebellum exhibit some uncharacteristic morphologies, but that these abnormalities are most likely the consequence of environmental alterations produced by the mutant gene.

  10. Using a non-physical behavioural barrier to alter migration routing of juvenile Chinook salmon in the Sacramento–San Joaquin River Delta

    USGS Publications Warehouse

    Perry, R.W.; Romine, J.G.; Adams, N.S.; Blake, A.R.; Burau, J.R.; Johnston, S.V.; Liedtke, T.L.

    2012-01-01

    Anthropogenic alterations to river systems, such as irrigation and hydroelectric development, can negatively affect fish populations by reducing survival when fish are routed through potentially dangerous locations. Non-physical barriers using behavioural stimuli are one means of guiding fish away from such locations without obstructing water flow. In the Sacramento–San Joaquin River Delta, we evaluated a bio-acoustic fish fence (BAFF) composed of strobe lights, sound and a bubble curtain, which was intended to divert juvenile Chinook salmon (Oncorhynchus tshawytscha) away from Georgiana Slough, a low-survival migration route that branches off the Sacramento River. To quantify fish response to the BAFF, we estimated individual entrainment probabilities from two-dimensional movement paths of juvenile salmon implanted with acoustic transmitters. Overall, 7.7% of the fish were entrained into Georgiana Slough when the BAFF was on, and 22.3% were entrained when the BAFF was off, but a number of other factors influenced the performance of the BAFF. The effectiveness of the BAFF declined with increasing river discharge, likely because increased water velocities reduced the ability of fish to avoid being swept across the BAFF into Georgiana Slough. The BAFF reduced entrainment probability by up to 40 percentage points near the critical streakline, which defined the streamwise division of flow vectors entering each channel. However, the effect of the BAFF declined moving in either direction away from the critical streakline. Our study shows how fish behaviour and the environment interacted to influence the performance of a non-physical behavioural barrier in an applied setting.

  11. Developing Depositional Models for Mercury Contaminated Floodplain Deposits Using Geomorphic Mapping and GIS in South River, Virginia

    NASA Astrophysics Data System (ADS)

    Barbieri, A.; Pizzuto, J.; O'Neal, M. A.; Rhoades, E.

    2007-12-01

    Mercury was introduced into the South River from the 1930s to the 1950s from an industrial plant in Waynesboro, Virginia. Mercury contamination in fish tissue continues to exceed acceptable levels. The contaminated sediments in the river's floodplains are probably the present source of mercury to the South River ecosystem. Locating and determining the extent and depositional history of these deposits are important for understanding the mercury cycle in the river as well as for remediation plans. The South River is a sinuous, single thread alluvial river with frequent bedrock exposures along its bed and banks. Overbank deposits are discontinuous and thin. Rates of lateral migration by the South River are extremely low, averaging 0.02 m/yr, and the river has been influenced by mill dams along a 19 km study reach. This 19 km section of the 37 km river reach was selected for the study because of its high concentration of Hg. Six different categories of floodplain deposits dating from 1937-2005 have been identified throughout the river using studies of historical aerial photographs in a GIS framework, field mapping, dendro- and radionuclide dating, grain size and Hg analysis. Not surprisingly, traditional depositional models of meandering rivers do not apply. Floodplain depositional units include mill dam deposits, point bar/bench deposits, concave bank bench deposits, islands, cattle deposits, and tributary confluences deposits. The most important deposits for sequestering historic mercury are those that also store the most silt and clay. These include mill dam deposits, point bar/bench deposits, concave bank deposits, and tributary confluence deposits. Many of these deposits represent reservoirs of mercury-contaminated sediments that could supply significant amounts of mercury into the river presently and in the future.

  12. Magnetoimpedance of thin film meander with composite coating layer containing Ni nanoparticles

    NASA Astrophysics Data System (ADS)

    Lodewijk, K. J.; Fernandez, E.; Garcia-Arribas, A.; Kurlyandskaya, G. V.; Lepalovskij, V. N.; Safronov, A. P.; Kooi, B. J.

    2014-05-01

    Giant magnetoimpedance (GMI) [FeNi/Cu]4/FeNi/Cu/[FeNi/Cu]4/FeNi sensing meander elements were designed and tested aiming to develop a new instrumentation for characterization of polymer/magnetic nanoparticles composites. Acrylic copolymer of 95% of butyl methacrylate and 5% of methacrylic acid was used as polymer matrix of the composite. It was shown that GMI meander sensing elements are capable of detecting Ni nanoparticles spread in the polymer matrix. Polymeric composites filled with magnetic nanoparticles in small concentration are able to enhance GMI meander sensitivity.

  13. Wild, scenic, and transcendental rivers

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    “A more lovely stream than this has never flowed on Earth,” 19th century American author Nathaniel Hawthorne wrote about the confluence of the Assabet and Concord Rivers, streams that meander about 40 km west of Boston, Massachusetts.Segments of these streams as well as the Assabet River became the newest additions to the U.S. National Wild and Scenic Rivers System, when President Bill Clinton signed into law the “Sudbury, Assabet, and Concord Wild and Scenic River Act” on April 9.

  14. Insights into geomorphic and vegetation spatial patterns within dynamic river floodplains using soft classification approaches

    NASA Astrophysics Data System (ADS)

    Guneralp, I.; Filippi, A. M.; Guneralp, B.; You, M.

    2014-12-01

    Lowland rivers in broad alluvial floodplains create one of the most dynamic landscapes, governed by multiple, and commonly nonlinear, interactions among geomorphic, hydrologic, and ecologic processes. Fluvial landforms and land-cover patches composing the floodplains of lowland rivers vary in their shapes and sizes because of variations in vegetation biomass, topography, and soil composition (e.g., of abandoned meanders versus accreting bars) across space. Such floodplain heterogeneity, in turn, influences future river-channel evolution by creating variability in channel-migration rates. In this study, using Landsat 5 Thematic Mapper data and alternative image-classification approaches, we investigate geomorphic and vegetation spatial patterns in a dynamic large tropical river. Specifically, we examine the spatial relations between river-channel planform and fluvial-landform and land-cover patterns across the floodplain. We classify the images using both hard and soft classification algorithms. We characterize the structure of geomorphic landform and vegetation components of the floodplain by computing a range of class-level landscape metrics based on the classified images. Results indicate that comparable classification accuracies are accrued for the inherently hard and (hardened) soft classification images, ranging from 89.8% to 91.8% overall accuracy. However, soft classification images provide unique information regarding spatially-varying similarities and differences in water-column properties of oxbow lakes and the main river channel. Proximity analyses, where buffer zones along the river with distances corresponding to 5, 10, and 20 river-channel widths are constructed, reveal that the average size of forest patches first increase away from the river banks but they become sparse after a distance of 10 channel widths away from the river.

  15. Impact of channel incision on the hydraulics of flood flows: Examples from Polish Carpathian rivers

    NASA Astrophysics Data System (ADS)

    Wyżga, Bartłomiej; Zawiejska, Joanna; Radecki-Pawlik, Artur

    2016-11-01

    Channel deepening may result from channel incision or river metamorphosis changing a wide and shallow channel to a narrow and deep one. As only the first type of channel change leads to increased flow capacity of the channel, a lowering of water stage associated with a given discharge rather than a lowering of river bed should be used to identify channel incision. A lowering of minimum annual stage at gauging stations is typically used to assess the relative importance of channel incision along a river or within a particular region. Rivers of the Polish Carpathians incised by 0.5-3.8 m over the twentieth century, with the amount of incision being greater in their lower and middle courses than in the upper ones. Variability in the hydraulic importance of channel incision with increasing river size is analysed by comparing changes in the frequency of valley floor inundation at gauging stations located along the seventh-order Dunajec River. Despite a lower absolute amount of channel incision in the upper river course, here incision has increased channel conveyance and reduced the frequency of valley floor inundation considerably more than in the lower course. Hydraulic effects of channel incision depend also on lateral stability of an incising river. Low-energy rivers from the eastern part of the Polish Carpathians remained laterally stable during channel incision. This has resulted in substantial lowering of stages for low flood discharges and markedly smaller one for high-magnitude floods, whereas velocity of the flows conveyed over the highly elevated floodplains has decreased considerably. In high-energy rivers from the western part of the Polish Carpathians, alternation of incision and lateral channel migration has led to the formation of incised meander belts, with substantially lowered stages for all flood discharges and increased velocity of the flows conveyed over the newly-formed, low-lying floodplains.

  16. Controls on the Alluviation of Oxbow Lakes by Bed Load as Observed Along the Sacramento River of California

    NASA Astrophysics Data System (ADS)

    Constantine, J. A.; Dunne, T.; Piegay, H.; Kondolf, G. M.

    2007-12-01

    As the products of meander cutoff that are widespread within many floodplains, oxbow lakes can affect the ability of rivers to migrate across their valleys, as well as physical and chemical exchanges between the river and floodplain environment. The particular functions of the oxbow lake are determined by the manner it is filled by sedimentation. Although the alluviation of oxbow lakes has been observed in natural settings and generalized by means of rules in planform evolution models, no theory exists to explain how oxbow lakes are filled because the controls on the process have not been widely studied or physically interpreted. Utilizing existing theory and field data from lakes of the Sacramento River, we examined the controls on oxbow alluviation by bed load and found that the transport of bed material through a channel abandoned by cutoff is highly sensitive to the orientation of the abandoned-channel entrance. In particular, the diversion angle, the angle between the approaching active- channel flow and the abandoned-channel entrance, is a direct control on discharge through the abandoned channel, and thus can significantly reduce boundary shear-stress and limit the transport capacity of bed load. The higher the angle, the more greatly reduced is the capacity to transmit bed material, and the more quickly the channel is hydraulically disconnected as diverted bed load rapidly aggrades the channel entrance. In contrast, the lower the angle, the longer the duration the channel remains hydraulically connected, and the more likely it will experience filling and narrowing by bed load because sufficient flow allows for the downstream and transverse transport of bed material. Our findings from the Sacramento River compare well to observations from other large meandering rivers and may explain why some lakes are terrestrialized within decades of cutoff, whereas others remain as open-water habitat for considerably longer.

  17. Monitoring of the in-river migration of smolts from two groups of spring chinook salmon, Oncorhynchus tshawytscha (Walbaum), with different profiles of Renibacterium salmoninarum infection

    USGS Publications Warehouse

    Pascho, R.J.; Elliott, D.G.; Achord, S.

    1993-01-01

    Broodstock segregation based on the measurement of maternal Renibacterium salmoninarum infection levels by the enzyme-linked immunosorbent assay (ELISA) and the membrane filtration-fluorescent antibody technique (MF-FAT) was previously shown to affect the prevalence and levels of bacterial kidney disease (BKD) in progeny of chinook salmon, Oncorhynchus tshawytscha (Walbaum), during hatchery rearing. Subgroups of fish from that study were marked with passive integrated transponder (PIT) tags, and monitored by PIT-tag detectors during the first 342km of their migration to the Pacific Ocean. Differences in the recovery of tagged fish were significant (P≤ 0·01) at each detection point and became more pronounced as the fish moved downstream. Cumulative recoveries of fish from the low-BKD group and the high-BKD group, respectively, were 31% and 28% after 116km, 44% and 37% after 176km, and 51% and 42% after 342km. There were no apparent differences in the migration timing of the two groups to the first detection point. The data suggested that in-river survival was higher in the progeny group from parents that had low R. salmoninarum infection levels or tested negative for R. salmoninarum (low-BKD group) than in the group female parents with high infection levels (high-BKD group).

  18. Conservation physiology in practice: how physiological knowledge has improved our ability to sustainably manage Pacific salmon during up-river migration.

    PubMed

    Cooke, Steven J; Hinch, Scott G; Donaldson, Michael R; Clark, Timothy D; Eliason, Erika J; Crossin, Glenn T; Raby, Graham D; Jeffries, Ken M; Lapointe, Mike; Miller, Kristi; Patterson, David A; Farrell, Anthony P

    2012-06-19

    Despite growing interest in conservation physiology, practical examples of how physiology has helped to understand or to solve conservation problems remain scarce. Over the past decade, an interdisciplinary research team has used a conservation physiology approach to address topical conservation concerns for Pacific salmon. Here, we review how novel applications of tools such as physiological telemetry, functional genomics and laboratory experiments on cardiorespiratory physiology have shed light on the effect of fisheries capture and release, disease and individual condition, and stock-specific consequences of warming river temperatures, respectively, and discuss how these findings have or have not benefited Pacific salmon management. Overall, physiological tools have provided remarkable insights into the effects of fisheries capture and have helped to enhance techniques for facilitating recovery from fisheries capture. Stock-specific cardiorespiratory thresholds for thermal tolerances have been identified for sockeye salmon and can be used by managers to better predict migration success, representing a rare example that links a physiological scope to fitness in the wild population. Functional genomics approaches have identified physiological signatures predictive of individual migration mortality. Although fisheries managers are primarily concerned with population-level processes, understanding the causes of en route mortality provides a mechanistic explanation and can be used to refine management models. We discuss the challenges that we have overcome, as well as those that we continue to face, in making conservation physiology relevant to managers of Pacific salmon.

  19. Conservation physiology in practice: how physiological knowledge has improved our ability to sustainably manage Pacific salmon during up-river migration

    PubMed Central

    Cooke, Steven J.; Hinch, Scott G.; Donaldson, Michael R.; Clark, Timothy D.; Eliason, Erika J.; Crossin, Glenn T.; Raby, Graham D.; Jeffries, Ken M.; Lapointe, Mike; Miller, Kristi; Patterson, David A.; Farrell, Anthony P.

    2012-01-01

    Despite growing interest in conservation physiology, practical examples of how physiology has helped to understand or to solve conservation problems remain scarce. Over the past decade, an interdisciplinary research team has used a conservation physiology approach to address topical conservation concerns for Pacific salmon. Here, we review how novel applications of tools such as physiological telemetry, functional genomics and laboratory experiments on cardiorespiratory physiology have shed light on the effect of fisheries capture and release, disease and individual condition, and stock-specific consequences of warming river temperatures, respectively, and discuss how these findings have or have not benefited Pacific salmon management. Overall, physiological tools have provided remarkable insights into the effects of fisheries capture and have helped to enhance techniques for facilitating recovery from fisheries capture. Stock-specific cardiorespiratory thresholds for thermal tolerances have been identified for sockeye salmon and can be used by managers to better predict migration success, representing a rare example that links a physiological scope to fitness in the wild population. Functional genomics approaches have identified physiological signatures predictive of individual migration mortality. Although fisheries managers are primarily concerned with population-level processes, understanding the causes of en route mortality provides a mechanistic explanation and can be used to refine management models. We discuss the challenges that we have overcome, as well as those that we continue to face, in making conservation physiology relevant to managers of Pacific salmon. PMID:22566681

  20. Morphodynamics of Migration Surveyed at Large Spatial and Temporal Scales

    NASA Astrophysics Data System (ADS)

    Aalto, R.; Schwendel, A.; Nicholas, A. P.

    2012-04-01

    The controls on rivers migration are diverse and often complex. One way forwards is to select study rivers that meet certain simplifying conditions: near-pristine (no anthropogenic complications), large size and rapid mobility (resulting in significant change viewable in Landsat imagery), limited geological complexity (no bedrock), steady hydrology (relatively little variation in discharge and sediment load), and simplified base level control (no tides or other substantial perturbations). Such systems could then be measured at appropriate spatial and temporal scales to extract the reach-scale dynamics while averaging out the more stochastic behaviour of individual meander bends. Such an approach requires both special rivers and novel techniques, which we have investigated and present here. The two explored examples are the near-pristine Beni River basin in northern Bolivia (800 km channel length) and the similarly natural Fly-Strickland River basin in Papua New Guinea (400 km channel length) - large, tropical sand-bedded rivers that meet the above criteria. First, we conducted a GIS analysis of migration using image collections that include 1950s military aerial reconnaissance -- this allowed us to characterize mobility decades before the first Landsat satellite was launched. Following this approach, we characterized migration rate, sinuosity, and other parameters at the reach scale of 10km and the temporal scale of 50+ years, with clear patterns of rate and morphology emerging as a function of location within the systems. We conducted extensive fieldwork to explore potential controls on these patterns, with the focus of this talk being the results from DGPS surveys of river and valley slope. The length scale of these rivers, the density of the forested floodplains, and the hostility of the environments precluded the use of standard RTK-DGPS methods. Instead, we employed three novel techniques for long baseline (100s of km) DGPS surveys: OmniStar HP/XP GLONASS

  1. Examining the Relationship Between Suspended Sand Load and Bedload on the Colorado River Using Concurrent Measurements of Suspended Sand and Observations of Sand Dune Migration.

    NASA Astrophysics Data System (ADS)

    Ashley, T.; McElroy, B. J.; Buscombe, D.; Grams, P. E.; Kaplinski, M. A.

    2015-12-01

    Spatial variability in sediment flux is directly related to geomorphic change. Along the Colorado River, measurements of sediment flux are used to track changes in sediment storage and time the release of controlled floods aimed at building eroded sandbars. The very high uncertainty typical of measurements of sediment flux has been reduced by a program of continuous measurement of suspended-sediment concentration by acoustic surrogates. However, there is still significant uncertainty in calculations of total flux. A large fraction of that uncertainty may be caused by overly simplified treatment of bedload flux, which is currently estimated as a constant 5% of the suspended sand flux. That constant is based on estimates of bedform migration rate made with side-scan sonar. Here, we apply theory which relates bedform migration and streamwise sediment flux, to bathymetric data collected at unprecedented temporal and spatial resolution adjacent to the USGS sediment monitoring station above Diamond Creek (362 km downstream from Lees Ferry, AZ). Quantitative time series measurements of reach averaged bedform transport are calculated and compared to fluxes estimated by expressing bedload as a constant fraction of suspended load. Over the range of discharges expected during normal dam operations, bedload transport estimated from the migration of bedforms in the study reach is at least 20% of instantaneous suspended sand load measured at the gage. While bedload appears to be controlled primarily by discharge (and therefore transport capacity of the flow), suspended sand load varies inversely with the grain size of suspended material, suggesting dependence on sediment supply. Sediment transport capacity can vary significantly at a given discharge depending on local hydraulic geometry, so it is likely that there is more spatial variability in bedload transport than suspended sand transport.

  2. Generation and migration of Bitumen and oil from the oil shale interval of the Eocene Green River formation, Uinta Basin, Utah

    USGS Publications Warehouse

    Johnson, Ronald C.; Birdwell, Justin E.; Mercier, Tracey J.

    2016-01-01

    The results from the recent U.S. Geological Survey assessment of in-place oil shale resources of the Eocene Green River Formation, based primarily on the Fischer assay method, are applied herein to define areas where the oil shale interval is depleted of some of its petroleum-generating potential along the deep structural trough of the basin and to make: (1) a general estimates of the amount of this depletion, and (2) estimate the total volume of petroleum generated. Oil yields (gallons of oil per ton of rock, GPT) and in-place oil (barrels of oil per acre, BPA) decrease toward the structural trough of the basin, which represents an offshore lacustrine area that is believed to have originally contained greater petroleum-generating potential than is currently indicated by measured Fischer assay oil yields. Although this interval is considered to be largely immature for oil generation based on vitrinite reflectance measurements, the oil shale interval is a likely source for the gilsonite deposits and much of the tar sands in the basin. Early expulsion of petroleum may have occurred due to the very high organic carbon content and oil-prone nature of the Type I kerogen present in Green River oil shale. In order to examine the possible sources and migration pathways for the tar sands and gilsonite deposits, we have created paleogeographic reconstructions of several oil shale zones in the basin as part of this study.

  3. Pilot study to access the role of Ceratomyxa shasta infection in mortality of fall-run Chinook smolts migrating through the lower Klamath River in 2008

    USGS Publications Warehouse

    Foott, Scott; Stutzer, Greg; Fogerty, R.; Hansel, Hal; Juhnke, Steven; Beeman, John W.

    2009-01-01

    Apparent survival and migration rate of radio-tagged hatchery subyearling Chinook salmon released at Iron Gate Hatchery was monitored in the Klamath River to see if the timing of mortality coincided with observations of ceratomyxosis in re-captured coded wire tag cohorts. Despite rapid emigration, these relatively large (mean fork length 92 mm) smolts had a cumulative apparent survival to the estuary of 0.074 (SE 0.024) and standardized rates of survival per 100 km tended to decrease linearly with distance from the hatchery. The last fish detection occurred 26 days after release but median travel time between Iron Gate Hatchery (rkm 309) and the last receiver near the Klamath estuary (Blake’s Riffle rkm 13) was about 10 days. The majority of apparent mortality (8-10 d post-release) occurred before disease from Ceratomyxa shasta infection is expected after exposure to infectious waters. Despite numerous observations of ceratomyxosis in the Klamath R. during June, an obvious link between disease and apparent survival was not present in this study. Future studies should examine the acute (e.g., predator types and densities) and chronic (e.g., swimming performance impairment due to disease) mortality factors for juvenile Chinook salmon smolts in the Klamath River.

  4. Insights on the opening of the Galerian mammal migration pathway from magnetostratigraphy of the Pleistocene marine-continental transition in the Arda River section (northern Italy)

    NASA Astrophysics Data System (ADS)

    Monesi, Edoardo; Muttoni, Giovanni; Scardia, Giancarlo; Felletti, Fabrizio; Bona, Fabio; Sala, Benedetto; Tremolada, Fabrizio; Francou, Carlo; Raineri, Gianluca

    2016-09-01

    We investigated the magnetostratigraphy of the Arda River section (northern Italy) where the transition from marine to continental sedimentation occurring in the Po River basin during the Pleistocene is registered. Four magnetic polarity reversals were used to construct an age model of sedimentation aided by marine biostratigraphy and tied to a standard δ18O curve from the literature. The section spans from the Olduvai subchron (1.94-1.78 Ma) across the Jaramillo subchron (1.07-0.99 Ma) up to the Brunhes-Matuyama boundary (0.78 Ma). The onset of continental deposition occurred during marine isotope stage (MIS) 30 at ˜1.04 Ma. An association of Villafranchian and Early Galerian mammals, including Sus strozzii and Ursus dolinensis, has been found in the continental sediments dated to MIS 29-27 (˜0.99 Ma). Above follows a prominent fluvial conglomerate attributed to the first major lowstand of the Pleistocene culminating with MIS 22 at ˜0.9 Ma during the late Early Pleistocene climate turnover (EPT). These and other data from the literature are used to reconstruct the onset of continental deposition in the greater Po basin and shed light on the opening of the migration pathway that brought far-traveled Galerian mammal immigrants to enter Europe for the first time during the EPT.

  5. Assessment, validation and intercomparison of operational models for predicting tritium migration from routine discharges of nuclear power plants: the case of Loire River.

    PubMed

    Goutal, Nicole; Luck, Marilyne; Boyer, Patrick; Monte, Luigi; Siclet, Françoise; Angeli, Giacomo

    2008-02-01

    During last decades, a number of projects have been launched to validate models for predicting the behaviour of radioactive substances in the environment. The project of the "Aquatic" working group of the project EMRAS (Environmental Modelling for Radiation Safety) organised by the International Atomic Energy Agency (IAEA) was based on the validation and assessment of models for predicting the behaviour of radionuclides in the aquatic ecosystems. The present paper describes a blind test of models aimed at assessing the dispersion of tritium releases in the Loire River (France), on a large domain ( approximately 350km) and on a period of six months, by comparing the results obtained by operational-to-experimental values of tritium concentration at Angers, a city along the Loire River. The common conclusion is that the models used by the different participants namely 1D models and models based on a schematic hydraulic (box models) are reliable tools for tritium transport modelling. Nevertheless, the importance of proper and detailed hydrological data for the appropriate prediction of pollutant migration in water is demonstrated by the example provided during this study.

  6. Channel Evolution on the Lower Elwha River, Washington, 1939-2006

    USGS Publications Warehouse

    Draut, Amy E.; Logan, Joshua B.; McCoy, Randall E.; McHenry, Michael; Warrick, Jonathan A.

    2008-01-01

    Analyses of historical aerial photographs of the lower Elwha River, Clallam County, Washington, reveal rates and patterns of channel change in this dammed, anabranching river between 1939 and 2006. Absolute positional changes of the active-floodplain margins, which commonly exceeded 50 m over that interval, have exceeded 400 m locally. Annualized rates of channel movement were typically ~2 to 10 m/yr; higher annualized rates over some time intervals are attributable to the formation of new channels by episodic avulsion. Channel movement by more gradual lateral meander migration was also common. Anthropogenic modification of the floodplain between the 1940s and 1980s substantially altered channel form and position. This analysis of rates and patterns of channel change over nearly 70 years on the lower Elwha River is intended to characterize the evolution of the river throughout most of the time interval when two large dams have been in place upstream. Channel morphology and rates of channel movement are expected to change significantly in response to removal of the dams and re-establishment of the upstream sediment supply during a major river-restoration project.

  7. Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002-2004.

    PubMed

    Henny, Charles J; Hill, Elwood F; Grove, Robert A; Chelgren, Nathan D; Haggerty, Patricia K

    2017-01-01

    This telemetry study is an extension of our 1997-2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000-04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is "whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? " Based upon telemetry signals until 90-110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic mining

  8. Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002–2004

    USGS Publications Warehouse

    Henny, Charles J.; Hill, Elwood F.; Grove, Robert A.; Chelgren, Nathan; Haggerty, Patricia K.

    2017-01-01

    This telemetry study is an extension of our 1997–2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000–04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is “whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? ” Based upon telemetry signals until 90–110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20 d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47 µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic

  9. Imaging beneath the skin of large tropical rivers: System morphodynamics of the Fly and Beni Rivers revealed by novel sub-surface sonar, deep coring, and modelling

    NASA Astrophysics Data System (ADS)

    Aalto, R. E.; Grenfell, M.; Lauer, J. W.

    2011-12-01

    channel negotiates "dog-leg" meanders and traverses a bed composed of a stacked sequence of fine layers; 3) An ancient channel network buried below the current bed of Lake Murray, indicating a ~10m rise in the Strickland River near that location; 4) The prevalence of clay in many of our deep cores throughout the Strickland, Fly, and Lake Murray floodplains; and 5) 14-C dating of deep cores which indicates that the entire Fly River system aggraded >10m rapidly during the mid Holocene. It appears that clay units dominate large portions of the channel bed. Furthermore, this clay often appears to control the morphodynamics of the channel -- as observed in the field and substantiated with modelling in Delft3D. We have recently completed a similar sonar/coring survey of 100s of km of the Beni River in Northern Bolivia. Particular attention was paid to the subsurface structure of meander bends, with an aim of understanding the controls on migration rates in this rapidly evolving system. Results are compared to GIS and modelling analyses of channel migration. We conclude with a synthesis of how cohesive clay-rich lithology can potentially play a major role in orchestrating the channel morphodynamics and Holocene evolution of a range of large tropical rivers.

  10. Microbial water quality during the northern migration of Sandhill Cranes (Grus canadensis) at the central Platte River, Nebraska

    USGS Publications Warehouse

    Moser, Matthew T.

    2014-01-01

    The central Platte River is an important resource in Nebraska. Its water flows among multiple channels and supports numerous beneficial uses such as drinking water, irrigation for agriculture, groundwater recharge, and recreational activities. The central Platte River valley is an important stopover for migratory waterfowl and cranes, such as the Whooping (Grus americana) and Sandhill Cranes (Grus canadensis), in their annual northward traversal of the Central Flyway. Waterfowl, cranes, and other migratory birds moving across international and intercontinental borders may provide long-range transportation for any microbial pathogen they harbor, particularly through the spread of feces. Samples were collected weekly in the study reach from three sites (upstream, middle, and downstream from the roosting locations) during the spring of 2009 and 2010. The samples were analyzed for avian influenza, Escherichia coli, Cryptosporidium, Giardia, Campylobacter, and Legionella. Analysis indicates that several types of fecal indicator bacteria and a range of viral, protozoan, and bacterial pathogens were present in Sandhill Crane excreta. These bacteria and pathogens were present at a significantly higher frequency and densities in water and sediments when the Sandhill Cranes were present, particularly during evening roosts within the Platte River environment.

  11. Spring migration ecology of the mid-continent sandhill crane population with an emphasis on use of the Central Platte River Valley, Nebraska

    USGS Publications Warehouse

    Krapu, Gary L.; Brandt, David A.; Kinzel, Paul J.; Pearse, Aaron T.

    2014-01-01

    We conducted a 10-year study (1998–2007) of the Mid-Continent Population (MCP) of sandhill cranes (Grus canadensis) to identify spring-migration corridors, locations of major stopovers, and migration chronology by crane breeding affiliation (western Alaska–Siberia [WA–S], northern Canada–Nunavut [NC–N], west-central Canada–Alaska [WC–A], and east-central Canada–Minnesota [EC–M]). In the Central Platte River Valley (CPRV) of Nebraska, we evaluated factors influencing staging chronology, food habits, fat storage, and habitat use of sandhill cranes. We compared our findings to results from the Platte River Ecology Study conducted during 1978–1980. We determined spring migration corridors used by the breeding affiliations (designated subpopulations for management purposes) by monitoring 169 cranes marked with platform transmitter terminals (PTTs). We also marked and monitored 456 cranes in the CPRV with very high frequency (VHF) transmitters to evaluate length and pattern of stay, habitat use, and movements. An estimated 42% and 58% of cranes staging in the CPRV were greater sandhill cranes (G. c. tabida) and lesser sandhill cranes (G. c. canadensis), and they stayed for an average of 20 and 25 days (2000–2007), respectively. Cranes from the WA–S, NC–N, WC–A, and EC–M affiliations spent an average of 72, 77, 52, and 53 days, respectively, in spring migration of which 28, 23, 24, and 18 days occurred in the CPRV. The majority of the WA–S subpopulation settled in the CPRV apparently because of inadequate habitat to support more birds upstream, although WA–S cranes accounted for >90% of birds staging in the North Platte River Valley. Crane staging duration in the CPRV was negatively correlated with arrival dates; 92% of cranes stayed >7 days. A program of annual mechanical removal of mature stands of woody growth and seedlings that began in the early 1980s primarily in the main channel of the Platte River has allowed distribution of crane

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

    SciTech Connect

    Smith, Steven G.; Muir, William D.; Marsh, Douglas M.

    2005-10-01

    In 2004, the National Marine Fisheries Service and the University of Washington completed the twelfth year of a study to estimate survival and travel time of juvenile salmonids (Oncorhynchus spp.) passing through dams and reservoirs on the Snake and Columbia Rivers. All estimates were derived from detections of fish tagged with passive integrated transponder tags (PIT tags). We PIT tagged and released a total of 19,621 hatchery steelhead, 8,128 wild steelhead, and 9,227 wild yearling Chinook salmon at Lower Granite Dam. In addition, we utilized fish PIT tagged by other agencies at traps and hatcheries upstream from the hydropower system and sites within the hydropower system. PIT-tagged smolts were detected at interrogation facilities at Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Dams and in the PIT-tag detector trawl operated in the Columbia River estuary. Survival estimates were calculated using a statistical model for tag-recapture data from single release groups (the single-release model). Primary research objectives in 2004 were to (1) estimate reach survival and travel time in the Snake and Columbia Rivers throughout the migration period of yearling Chinook salmon O. tshawytscha and steelhead O. mykiss; (2) evaluate relationships between survival estimates and migration conditions; and (3) evaluate the survival-estimation models under prevailing conditions. This report provides reach survival and travel time estimates for 2004 for PIT-tagged yearling Chinook salmon (hatchery and wild), hatchery sockeye salmon O. nerka, hatchery coho salmon O. kisutch, and steelhead (hatchery and wild) in the Snake and Columbia Rivers. Results are reported primarily in the form of tables and figures; details on methodology and statistical models used are provided in previous reports cited here. Survival and detection probabilities were estimated precisely for most of the 2004 yearling Chinook salmon and steelhead migrations. Hatchery and

  13. Mechanical Stress Effects on Electromigration Voiding in a Meandering Test Stripe

    NASA Technical Reports Server (NTRS)

    Lowry, L. E.; Tai, B. H.; Mattila, J.; Walsh, L. H.

    1993-01-01

    Earlier experimental findings concluded that electromigratin voids in these meandering stripe test structures were not randomly distributed and that void nucleation frequenly occurred sub-surface at the metal/thermal oxide interface.

  14. Employing turbulent and meandering time scales to modeling the contaminants enhanced horizontal dispersion

    NASA Astrophysics Data System (ADS)

    Ucker Timm, Andréa; Degrazia, Gervásio Annes; Roberti, Débora Regina; Anfossi, Domenico

    2009-08-01

    A Lagrangian stochastic particle dispersion model composed of two coupled Langevin equations, employing a new transport parameterization is used to study the meandering enhanced dispersion in a low wind speed stable atmospheric boundary layer (ABL). The meandering parameterization introduced into the Lagrangian stochastic dispersion model is expressed in terms of a characteristic phenomenological meandering period and of the horizontal local turbulent time scales associated with a fully developed turbulence. The results of this new method are shown to agree with the field observations of Idaho experiments and also with other different meandering dispersion models. The major advance shown throughout this paper is as it follows: For air quality modeling it is highly necessary to include a parameterization that allows a correct description of the dispersion caused by the low-frequency horizontal wind oscillations.

  15. Channel-changing processes on the Santa Cruz River, Pima County, Arizona, 1936-86

    USGS Publications Warehouse

    Parker, John T.C.; ,

    1990-01-01

    Lateral channel change on the mainly ephemeral Santa Cruz River, Pima County, Arizona, causes damage and has spawned costly efforts to control bank erosion. Aerial photographs, historical data, and field observations are used to document the history of channel change since 1936. Variability in the nature and degree of channel change over time and space is shown. Three major channel change processes are: (1) migration by bank erosion during meander migration or initiation; (2) avulsion by overbank flooding and flood plain incision; (3) widening by erosion of low, cohesionless banks during floods and arroyo widening by undercutting and mass wasting of deeply incised vertical walls. The first process generally is a product of low to moderate flows or waning high flows; the others result mainly from higher flows, though sensitive arroyo walls may erode during relatively low flows. Channel morphology, bank resistance, and hydrology are factors determining the dominant channel-changing process on a particular reach of the river. Present river morphology reflects high flows since the 1960's.

  16. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume XVI : Survival and Transportation Effects for Migrating Snake River Hatchery Chinook Salmon and Steelhead: Historical Estimates from 1996-2003.

    SciTech Connect

    Buchanan, Rebecca A.; Skalski, John R.

    2007-12-07

    In 2005, the University of Washington developed a new statistical model to analyze the combined juvenile and adult detection histories of PIT-tagged salmon migrating through the Federal Columbia River Power System (FCRPS). This model, implemented by software Program ROSTER (River-Ocean Survival and Transportation Effects Routine), has been used to estimate survival and transportation effects on large temporal and spatial scales for PIT-tagged hatchery spring and summer Chinook salmon and steelhead released in the Snake River Basin from 1996 to 2003. Those results are reported here. Annual estimates of the smolt-to-adult return ratio (SAR), juvenile inriver survival from Lower Granite to Bonneville, the ocean return probability from Bonneville to Bonneville, and adult upriver survival from Bonneville to Lower Granite are reported. Annual estimates of transport-inriver (T/I) ratios and differential post-Bonneville mortality (D) are reported on both a systemwide basis, incorporating all transport dams analyzed, and a dam-specific basis. Transportation effects are estimated only for dams where at least 5,000 tagged smolts were transported from a given upstream release group. Because few tagged hatchery steelhead were transported in these years, no transportation effects are estimated for steelhead. Performance measures include age-1-ocean adult returns for steelhead, but not for Chinook salmon. Annual estimates of SAR from Lower Granite back to Lower Granite averaged 0.71% with a standard error (SE) of 0.18% for spring Chinook salmon from the Snake River Basin for tagged groups released from 1996 through 2003, omitting age-1-ocean (jack) returns. For summer Chinook salmon from the Snake River Basin, the estimates of annual SAR averaged 1.15% (SE=0.31%). Only for the release years 1999 and 2000 did the Chinook SAR approach the target value of 2%, identified by the NPCC as the minimum SAR necessary for recovery. Annual estimates of SAR for hatchery steelhead from the

  17. Optimization of meander line radiators for frequency selective surfaces by using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Bucuci, Stefania C.; Dumitrascu, Ana; Danisor, Alin; Berescu, Serban; Tamas, Razvan D.

    2015-02-01

    In this paper we propose the use of frequency selective surfaces based on meander line radiators, as targets for monitoring slow displacements with synthetic aperture radars. The optimization of the radiators is performed by using genetic algorithms on only two parameters i.e., gain and size. As an example, we have optimized a single meander antenna, resonating in the X-band, at 9.65 GHz.

  18. Monitoring and Evaluation of Smolt Migration in the Columbia Basin : Volume XVIII: Survival and Transportation Effects of Migrating Snake River Wild Chinook Salmon and Steelhead: Historical Estimates From 1996-2004 and Comparison to Hatchery Results. Draft.

    SciTech Connect

    Buchanan, Rebecca A.; Skalski, John R.; Broms, Kristin

    2008-12-03

    The combined juvenile and adult detection histories of PIT-tagged wild salmonids migrating through the Federal Columbia River Power System (FCRPS) were analyzed using the ROSTER (River-Ocean Survival and Transportation Effects Routine) statistical release-recapture model. This model, implemented by software Program ROSTER, was used to estimate survival on large temporal and spatial scales for PIT-tagged wild spring and summer Chinook salmon and steelhead released in the Snake River Basin upstream of Lower Granite Dam from 1996 to 2004. In addition, annual results from wild salmonids were compared with results from hatchery salmonids, which were presented in a previous report in this series (Buchanan, R. A., Skalski, J. R., Lady, J. L., Westhagen, P., Griswold, J., and Smith, S. 2007, 'Survival and Transportation Effects for Migrating Snake River Hatchery Chinook Salmon and Steelhead: Historical Estimates from 1996-2003', Technical report, Bonneville Power Administration, Project 1991-051-00). These results are reported here. Annual estimates of the smolt-to-adult return ratio (SAR), juvenile inriver survival from Lower Granite to Bonneville, the ocean return probability from Bonneville to Bonneville, and adult upriver survival from Bonneville to Lower Granite are reported. Annual estimates of transport-inriver (T/I) ratios and differential post-Bonneville mortality (D) are reported on a dam-specific basis for release years with sufficient numbers of wild PIT-tagged smolts transported. Transportation effects are estimated only for dams where at least 1,000 tagged wild smolts were transported from a given upstream release group. Because few wild Chinook salmon and steelhead tagged upstream of Lower Granite Dam were transported before the 2003 release year, T/I and D were estimated only for the 2003 and 2004 release years. Performance measures include age-1-ocean adult returns for steelhead, but not for Chinook salmon. Spring and summer Chinook salmon release groups

  19. Field evaluation of larval odor and mixtures of synthetic pheromone components for attracting migrating sea lampreys in rivers.

    PubMed

    Meckley, Trevor D; Wagner, C Michael; Luehring, Mark A

    2012-08-01

    The sea lamprey, Petromyzon marinus, is a harmful invader of the Laurentian Great Lakes. The odor emitted by larval lampreys resident to streams attracts migrating adults to high quality spawning habitats. Three components of the larval pheromone have been identified and tested in laboratory settings: petromyzonol sulfate, petromyzosterol disulfate, and petromyzonamine disulfate. Here, we report the first field test of six mixtures of synthetic versions of these pheromone components, and we compare lamprey responses to these with those elicited by the complete larval odor in a natural stream. Exposure to larval odor both increased upstream movement and attracted migrants into the portion of a channel containing the odor. No tested combination of synthetic pheromone components proved similarly attractive. These findings suggest the existence of unknown additional components of the pheromone that await discovery and are likely necessary if the pheromone is to be useful in management of this pest. Further, we hypothesize that the complete pheromone mixture is necessary to attract migrants into spawning habitat at the conclusion of the migration, whereas a partial pheromone may be effective at the transition from lake to stream when natural factors both dilute and alter the ratio of components from that actually emitted by sea lamprey larvae.

  20. Survival and migration behavior of juvenile Coho Salmon in the Klamath River relative to discharge at Iron Gate Dam, Northern California, 2007

    USGS Publications Warehouse

    Beeman, John W.; Juhnke, Steve; Stutzer, Greg; Hetrick, Nicholas

    2008-01-01

    This report describes a study of survival and migration behavior of radio-tagged juvenile coho salmon (Oncorhynchus kisutch) in the Klamath River, northern California, in 2007. This was the third year of a multi-year study with the goal of determining the effects of discharge at Iron Gate Dam (IGD) on survival of juvenile coho salmon downstream. Survival and factors affecting survival were estimated in 2006 and 2007 after work in 2005 showed radio telemetry could be used effectively. The study has included collaborative efforts among U.S. Geological Survey (USGS), U.S. Fish and Wildlife Service (USFWS), the Karuk and Yurok Tribal Fisheries Departments, and the U.S. Bureau of Reclamation. The objectives of the study included: (1) estimating the survival of wild and hatchery juvenile coho salmon in the Klamath River downstream of Iron Gate Dam, determining the effects of discharge and other covariates on juvenile coho salmon survival (2) and migration (3), and (4) determining if fish from Iron Gate Hatchery (IGH) could be used as surrogates for the limited source of wild fish. We have been able to meet the first objective by estimating the survivals of hatchery and wild fish (when available) downstream of IGD. We have not yet met the second or third objectives, because we have been unable to separate effects of discharge from other environmental variables as they pertain to the survival or migration of juvenile coho salmon. This was foreseen when the study began, as it was known there would likely be no experimental discharges. A multi-year analysis will be conducted after the data for the third planned year are available. The fourth objective was initiated in 2006, but wild fish were not available in 2007. The next year wild fish may be available is in 2009, based on their 3-year cycle of abundance. River discharges during the 2007 study period (April 10 through July 28, 2007) were below average compared to the period of record beginning in 1962. Average daily

  1. Effect of nacelle on the wake meandering in Horns Rev wind farm

    NASA Astrophysics Data System (ADS)

    Yang, Xiaolei; Foti, Daniel; Sotiropoulos, Fotis

    2016-11-01

    Turbine wake meandering has considerable effects on the velocity deficit and turbulence intensity in the wake. However, the mechanism for wake meandering is still not well understood and low-order models cannot take into account the wake meandering effects accurately. A recent work by Kang, Yang and Sotiropoulos showed that the nacelle has a significant effect on the wake meandering of a hydrokinetic turbine. To examine the nacelle contributions to wake meandering and wake interactions in utility-scale wind farms, we simulate the atmospheric turbulent flow over the Horns Rev wind farm using large-eddy simulation with actuator type models. In a preliminary simulation on a coarse grid using actuator line model for turbine blades without a nacelle model, the computed power shows overall good agreement with field measurements. Fine grid simulations using an actuator surface model for turbine blades with and without a nacelle model are being carried out. The corresponding results will be presented with analysis on wake meandering dynamics using the technique proposed by Horward et al. and Foti et al.. This work was supported by DOE (DE-AC04-94AL85000), Xcel Energy (Grant RD4-13) and Sandia National Laboratories. Computational resources were provided by National Renewable Energy Laboratory and University of Minnesota Supercomputing Institute.

  2. Stratigraphy, depositional history, and petroleum geology of Lower Cretaceous Fall River formation, Powder River Basin, Wyoming

    SciTech Connect

    Ryer, T.A.; Gustason, E.R.

    1985-05-01

    The middle Albian Fall River Formation, better know to petroleum geologists as the Dakota Sandstone, constitutes a northwestward-thinning wedge of predominantly sandy strata under and overlain by marine shale. Two major episodes of deltaic progradation can be recognized in the formation, permitting mapping of lower and upper deltaic members. Study of outcrops, cores, and subsurface relationships indicates that the Fall River consists predominantly of fluvial strata in the southeastern part of the Powder River basin; delta-front and delta-plain facies, which are cut out and replaced locally by northwest-trending meander belts, predominate in an area that tends northeastward across the central part of the basin; the delta-front facies pinches out into offshore marine shale in the northwestern part of the basin. The large majority of Fall River stratigraphic trap-type fields produce oil and gas from sandy meander-belt deposits. The largest accumulations of hydrocarbons in traps of this type, as exemplified by the Powell-Mexican Springs trend (lower member) and the Coyote Creek-Miller Creek trend (upper member), occur in the more seaward parts of the deltaic members, near the seaward termini of meander-belt systems. Mapping of meander belts and of the surrounding deltaic deposits constitutes a necessary first step in exploration for stratigraphic traps within the Fall River Formation.

  3. The Regional Salmon Outmigration Study--survival and migration routing of juvenile Chinook salmon in the Sacramento-San Joaquin River Delta during the winter of 2008-09

    USGS Publications Warehouse

    Romine, Jason G.; Perry, Russell W.; Brewer, Scott J.; Adams, Noah S.; Liedtke, Theresa L.; Blake, Aaron R.; Burau, Jon R.

    2013-01-01

    Juvenile Chinook salmon (Oncorhynchus tshawytscha) emigrating from natal tributaries of the Sacramento River may use a number of migration routes to navigate the Sacramento-San Joaquin River Delta (hereafter called “the Delta”), each of which may influence their probability of surviving. We applied a mark-recapture model to data from acoustically tagged juvenile late fall-run Chinook salmon that migrated through the Delta during the winter of 2008–09 to estimate route entrainment, survival, and migration times through the Delta. A tag-life study was conducted to determine the potential for premature tag failure. Tag failure began after 12 days and continued until the 45th day. Travel times of tagged fish exceeded minimum tag-failure times, indicating that survival estimates obtained from this study were negatively biased due to tag failure prior to fish exiting the Delta. Survival estimates were not adjusted and represent the joint probability of tag survival and fish survival. However, relative comparisons of survival among Chinook salmon choosing different routes appeared to be robust to tag failure, and migration-routing parameters were unaffected by tag failure. Migration-routing patterns were consistent among release groups. The Sacramento River was the primary migration route for all release groups except one. The percentage of fish entering the Sacramento River ranged from 33 to 55 percent. Sutter and Steamboat Sloughs were the secondary migration route for 9 of the 10 releases. The percentage of fish migrating through this route ranged from 10 to 35 percent. Entrainment into the interior Delta ranged from 15 to 33 percent. The Delta Cross Channel gates were open for 7 of the 10 releases. Entrainment into the interior Delta through the cross channel ranged from 1 to 27 percent. We estimated route-specific survival for 10 release groups that were released between November 14, 2008, and January 19, 2009. Population-level survival through the Delta

  4. Influences of Relative Sea-Level Rise and Mississippi River Delta Plain Evolution on the Holocene Middle Amite River, Southeastern Louisiana

    USGS Publications Warehouse

    Autin, W.J.

    1993-01-01

    The Holocene geomorphic history of southeastern Louisiana's middle Amite River is recorded in the stratigraphy of three alloformations, identified in decreasing age as the Watson (WAT), Denham Springs (DS), and Magnolia Bridge (MAG). The WAT meander belt formed by at least 9000 yr B.P., when sea level was lower and the Amite River was tributary to a larger ancestral drainage basin. The DS became an active meander belt by at least 3000 yr B.P., in response to relative sea-level rise and eastward progradation of the Mississippi River delta plain. The MAG developed its meander belt, in part, during the European settlement of the drainage basin, and is now attempting to adjust to modern anthropogenic influences. Geomorphic influences on the middle Amite River floodplain have temporal and spatial components that induce regional- and local-scale effects. Regional extrinsic influences caused meander belt avulsion that produced alloformations. However, local influences produced intrinsic geomorphic thresholds that modified channel morphology within a meander belt but did not induce alloformation development. Base-level influences of the relative sea-level rise and the Mississippi River delta plain were so dominant that the effects of possible climate change were not recognized in the Holocene Amite River system.

  5. Facies and architectural element analysis of a meandering fluvial succession: The Permian Warchha Sandstone, Salt Range, Pakistan

    NASA Astrophysics Data System (ADS)

    Ghazi, Shahid; Mountney, Nigel P.

    2009-11-01

    The 30 to 155 m thick Early Permian (Artinskian) Warchha Sandstone of the Salt Range, Pakistan is a conglomerate, sandstone and claystone succession within which seven lithofacies types (Gt, St, Sp, Sr, Sh, Fl and Fm) occur in a predictable order as repeated fining-upward cycles. Common sedimentary structures in the conglomerates and sandstones include planar and trough cross-bedding, planar lamination, soft sediment-deformed bedding, compound cosets of strata with low-angle inclined bounding surfaces and lags of imbricated pebbles. Structures in the finer-grained facies include desiccation cracks, raindrop imprints, caliche nodules and bioturbation. Groups of associated facies are arranged into nine distinct architectural elements (channels, gravel bars, sandy bedforms, downstream and laterally accreting barforms, sand sheets, crevasse splays, levees, floodplain units and shallow lakes), which is consistent with a fluvial origin for the succession. The types of architectural elements present and their relationship to each other demonstrate that the Warchha Sandstone preserves a record of a meandering river system that drained the northern margin of Gondwanaland. The dominance of fine-grained (floodplain) facies over gravel-grade (channel-base) facies and the widespread occurrence of large-scale lateral accretion elements supports the interpretation of a high-sinuosity, meandering fluvial system in which channel bodies accumulated via the lateral accretion of point bars but in which the active channels covered only a small part of a broad floodplain at any time instant. Although the regional and temporal distribution of these deposits is complex, in broad terms the lower part is dominated by stacked, multistorey channel bodies, whereas single-storey channel elements isolated in abundant fine-grained floodplain deposits dominate the middle and upper parts of the formation.

  6. Temporal variation of meandering intensity and domain-wide lateral oscillations of the Gulf Stream

    NASA Technical Reports Server (NTRS)

    Lee, Tong; Cornillon, Peter

    1995-01-01

    The path of the Gulf Stream exhibits two modes of variability: wavelike spatial meanders associated with instability processes and large-sale lateral shifts of the path presumably due to atmospheric forcing. The objectives of this study are to examine the temporal variation of the intensity of spatial meandering in the stream, to characterize large-scale lateral oscillations in the stream's path, and to study the correlation betwen these two dynamically distinct modes of variability. The data used for this analysis are path displacemets ofthe Gulf Stream between 75 deg and 60 deg W obtained from AVHRR-derived (Advanced Very High Resolution Radiometer) infrared images for the period April 1982 through December 1989. Meandering intensity, measured by the spatial root-mean-sqaure displacement of the stream path, displays a 9-month dominant periodicity which is persistent through the study period. The 9-month fluctuation in meandering intensity may be related to the interaction of Rosseby waves with the stream. Interannual variation of meandering intensity is also found to be significant, with meandering being mich more intense during 1985 than it was in 1987. Annual variation, however,is weak and not well-defined.The spatially averaged position of the stream, which reflects nonmeandering large-scale lateral oscillations of the stream path, is dominated by an annual cycle. On average, the mean position is farthest north in November and farthest south in April. The first empirical orthogonal function mode of the space-time path displacements represents lateral oscillatins that are in-phase over the space-time domain. Interannual oscillations are also observed and are found to be weaker than the annual oscillation. The eigenvalue of the first mode indicates that about 21.5% of the total space-time variability of the stream path can be attibuted to domain-wide lateral oscillation. The correlation between meandering intensity and domain-wide lateral oscillations is very

  7. Holocene environment changes around the Sara Us River, northern China, revealed by optical dating of lacustrine-aeolian sediments

    NASA Astrophysics Data System (ADS)

    Zhao, Hui; Sheng, Yongwei; Li, Bo; Fan, Yuxin

    2016-04-01

    The Sara Us River is located along the boundary of the Mu Us Desert and the Chinese Loess Plateau in northern China. The river has cut down through Quaternary sediments creating 70-80 m deep valleys with thick lacustrine/aeolian sequences exposed. We applied optical stimulated luminescence on sediments from a Holocene section of aeolian sand/lacustrine deposits in the top of the river valley. The dating results show that a humid period existed from 7.1 to 2.0 ka ago as evidenced by two layers of peat and lacustrine sediments. However, compared to other published Holocene sections in the Sara Us River valleys close to the section under studying, the local environment experienced very complicated changes during the Holocene. All of the sections recorded a period with drought and/or cold before the Holocene at around 13 ka, and an episode of aridity after about 2 ka ago as evidenced by the layers of aeolian sand. However, the ages of the lacustrine and peat layers in these sections are substantially different. Geomorphological analysis by digital elevation models does not support the existence of a mega lake covering the study area at 2 ka. The intricate environmental changes may have been caused by the meandering of the Sara Us River. Environmental changes also strongly affected human migration in this area, which is documented by Chinese historical records.

  8. Flood plain and channel dynamics of the Quinault and Queets Rivers, Washington, USA

    USGS Publications Warehouse

    O'Connor, J. E.; Jones, M.A.; Haluska, T.L.

    2003-01-01

    Observations from this study and previous studies on the Queets River show that channel and flood-plain dynamics and morphology are affected by interactions between flow, sediment, and standing and entrained wood, some of which likely involve time frames similar to 200–500-year flood-plain half-lives. On the upper Quinault River and Queets River, log jams promote bar growth and consequent channel shifting, short-distance avulsions, and meander cutoffs, resulting in mobile and wide active channels. On the lower Quinault River, large portions of the channel are stable and flow within vegetated flood plains. However, locally, channel-spanning log jams have caused channel avulsions within reaches that have been subsequently mobile for several decades. In all three reaches, log jams appear to be areas of conifer germination and growth that may later further influence channel and flood-plain conditions on long time scales by forming flood-plain areas resistant to channel migration and by providing key members of future log jams. Appreciation of these processes and dynamics and associated temporal and spatial scales is necessary to formulate effective long-term approaches to managing fluvial ecosystems in forested environments.

  9. Historical perspectives on channel pattern in the Clark Fork River, Montana and implications for post-dam removal restoration

    NASA Astrophysics Data System (ADS)

    Woelfle-Erskine, C. A.; Wilcox, A. C.

    2009-12-01

    Active restoration approaches such as channel reconstruction have moved beyond the realm of small streams and are being applied to larger rivers. Uncertainties arising from limited knowledge, fluvial and ecosystem variability, and contaminants are especially significant in restoration of large rivers, where project costs and the social, infrastructural, and ecological costs of failure are high. We use the case of Milltown Dam removal on the Clark Fork River, Montana and subsequent channel reconstruction in the former reservoir to examine the use of historical research and uncertainty analysis in river restoration. At a cost of approximately $120 million, the Milltown Dam removal involves the mechanical removal of approximately 2 million cubic meters of sediments contaminated by upstream mining, followed by restoration of the former reservoir reach in which a single-thread meandering channel is being constructed. Historical maps, surveys, photographs, and accounts suggest a conceptual model of a multi-thread, anastomosing river in the reach targeted for channel reconstruction, upstream of the confluence of the Clark Fork and Blackfoot Rivers. We supplemented historical research with analysis of aerial photographs, topographic data, and USGS stage-discharge measurements in a lotic but reservoir-influenced reach of the Clark Fork River within our study area to estimate avulsion frequency (0.8 avulsions/year over a 70-year period) and average rates of lateral migration and aggradation. These were used to calculate the mobility number, a dimensionless relationship between channel filling and lateral migration timescales that can be used to predict whether a river’s planform is single or multi-threaded. The mobility number within our study reach ranged from 0.6 (multi-thread channel) to 1.7 (transitional channel). We predict that, in the absence of active channel reconstruction, the post-dam channel pattern would evolve to one that alternates between single and multi

  10. Numerically Simulating the Hydrodynamic and Water Quality Environment for Migrating Salmon in the Lower Snake River, 2002-2003 Technical Report.

    SciTech Connect

    Cook, C.; Richmond, M.; Coleman, A.

    2003-06-01

    Summer temperatures in the Lower Snake River can be altered by releasing cold waters that originate from deep depths within Dworshak Reservoir. These cold releases are used to lower temperatures in the Clearwater and Lower Snake Rivers and to improve hydrodynamic and water quality conditions for migrating aquatic species. This project monitored the complex three-dimensional hydrodynamic and thermal conditions at the Clearwater and Snake River confluence and the processes that led to stratification of Lower Granite Reservoir (LGR) during the late spring, summer, and fall of 2002. Hydrodynamic, water quality, and meteorological conditions around the reservoir were monitored at frequent intervals, and this effort is continuing in 2003. Monitoring of the reservoir is a multi-year endeavor, and this report spans only the first year of data collection. In addition to monitoring the LGR environment, a three-dimensional hydrodynamic and water quality model has been applied. This model uses field data as boundary conditions and has been applied to the entire 2002 field season. Numerous data collection sites were within the model domain and serve as both calibration and validation locations for the numerical model. Errors between observed and simulated data varied in magnitude from location to location and from one time to another. Generally, errors were small and within expected ranges, although, as additional 2003 field data becomes available, model parameters may be improved to minimize differences between observed and simulated values. A two-dimensional, laterally-averaged hydrodynamic and water quality model was applied to the three reservoirs downstream of LGR (the pools behind Little Goose, Lower Monumental, and Ice Harbor Dams). A two-dimensional model is appropriate for these reservoirs because observed lateral thermal variations during summer and fall 2002 were almost negligible; however, vertical thermal variations were quite large (see USACE 2003). The numerical

  11. Degree of Contamination and Sources of Polychlorinated Biphenyls in Meandering Road Creek and Woods Inlet of Lake Worth, Fort Worth, Texas, 2004 and 2006-07

    USGS Publications Warehouse

    Braun, Christopher L.; Wilson, Jennifer T.; Van Metre, Peter C.

    2008-01-01

    Lake Worth is a reservoir on the West Fork Trinity River on the western edge of Fort Worth, Texas. Air Force Plant 4 (AFP4) is on the eastern shore of Woods Inlet, an arm of Lake Worth that extends south from the main body of the lake. Two previous reports documented ele-vated polychlorinated biphenyl (PCB) concentrations in surficial sediment in Woods Inlet relative to those in surficial sediment in other parts of Lake Worth. This report presents the results of another USGS study, done in cooperation with the U.S. Air Force, to indicate the degree of PCB contamination of Meandering Road Creek and Woods Inlet and to identify possible sources of PCBs in Meandering Road Creek and Woods Inlet on the basis of suspended, streambed, and lake-bottom sediment samples collected there in 2004 and 2006-07. About 40 to 80 percent of total PCB concentrations (depending on how total PCB concentration is computed) in suspended sediment exceed the threshold effect concentration, a concentration below which adverse effects to benthic biota rarely occur. About 20 percent of total PCB concentrations (computed as sum of three Aroclors) in suspended sediment exceed the probable effect concentration, a concentration above which adverse effects to benthic biota are expected to occur frequently. About 20 to 30 percent of total PCB concentrations in streambed sediment exceed the threshold effect concentration; and about 6 to 20 percent of total PCB concentrations in lake-bottom (Woods Inlet) sediment exceed the threshold effect concentration. No streambed or lake-bottom sediment concentrations exceed the probable effect concentration. The sources of PCBs to Meandering Road Creek and Woods Inlet were investigated by comparing the relative distributions of PCB congeners of suspended sediment to those of streambed and lake-bottom sediment. The sources of PCBs were identified using graphical analysis of normalized concentrations (congener ratios) of 11 congeners. For graphical analysis, the

  12. Monitoring and Evaluation of Smolt Migration in the Columbia River Basin : Volume VI : Evaluation of the 2000 Predictions of the Run-Timing of Wild Migrant Chinook Salmon and Steelhead Trout, and Hatchery Sockeye Salmon in the Snake River Basin, and Combined Wild Hatchery Salminids Migrating to Rock Island and McNary Dams using Program RealTime.

    SciTech Connect

    Burgess, Caitlin

    1998-07-01

    Program RealTime provided tracking and forecasting of the 2000 in season outmigration via the internet for stocks of wild PIT-tagged spring/summer chinook salmon. These stocks were ESUs from nineteen release sites above Lower Granite dam, including Bear Valley Creek, Big Creek, Camas Creek (new), Cape Horn Creek, Catherine Creek, Elk Creek, Herd Creek, Imnaha River, Johnson Creek (new), Lake Creek, Loon Creek, Lostine River, Marsh Creek, Minam River, East Fork Salmon River (new), South Fork Salmon River, Secesh River, Sulfur Creek and Valley Creek. Forecasts were also provided for two stocks of hatchery-reared PIT-tagged summer-run sockeye salmon, from Redfish Lake and Alturas Lake (new); for a subpopulation of the PIT-tagged wild Snake River fall subyearling chinook salmon; for all wild Snake River PIT-tagged spring/summer yearling chinook salmon (new) and steelhead trout (new)detected at Lower Granite Dam during the 2000 outmigration. The 2000 RealTime project began making forecasts for combined wild- and hatchery-reared runs-at-large of subyearling and yearling chinook, coho, and sockeye salmon, and steelhead trout migrating to Rock Island and McNary Dams on the mid-Columbia River and the mainstem Columbia River. Due to the new (in 1999-2000) Snake River basin hatchery protocol of releasing unmarked hatchery-reared fish, the RealTime forecasting project no longer makes run-timing forecasts for wild Snake River runs-at-large using FPC passage indices, as it has done for the previous three years (1997-1999). The season-wide measure of Program RealTime performance, the mean absolute difference (MAD) between in-season predictions and true (observed) passage percentiles, improved relative to previous years for nearly all stocks. The average season-wide MAD of all (nineteen) spring/summer yearling chinook salmon ESUs dropped from 5.7% in 1999 to 4.5% in 2000. The 2000 MAD for the hatchery-reared Redfish Lake sockeye salmon ESU was the lowest recorded, at 6.0%, down

  13. A multifaceted approach to prioritize and design bank stabilization measures along the Big Sioux River, South Dakota, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multifaceted approach was used to manage fine-grained sediment loadings from river bank erosion along the Big Sioux River between Dell Rapids and Sioux Falls, South Dakota, USA. Simulations with the RVR Meander and CONCEPTS river-morphodynamics computer models were conducted to identify stream-ban...

  14. The dynamics of a meandering coastal jet in the lee of a cape

    NASA Astrophysics Data System (ADS)

    Duarte, Rui; Carton, Xavier; Poulin, Francis J.

    2016-05-01

    In a barotropic model of an oceanic channel, bounded to the north by a straight coast indented by a Gaussian cape, the evolution of a coastal jet is studied numerically. In the absence of the cape, the barotropic instability of the jet is determined. In the presence of the cape, a regular row of meanders develops downstream of this feature, and becomes stationary for a particular range of parameters. The relevant parameters are the velocity and width of the jet, size of the cape, and beta effect. The formation of meanders occurs first via the instability of the jet, then via the generation of vorticity anomalies at the cape, which are advected both downstream by the flow and offshore by the radiation of Rossby waves. Once the meanders are established, they remain stationary features if the propagation velocity of the meanders (due to the dipolar effect at the coast) opposes the jet velocity and the phase speed of the wave on the vorticity front. Finally, a steady state of a regular row of meanders is also obtained via a matrix method and is similar to that obtained in the time-dependent case.

  15. Competing growth processes induced by next-nearest-neighbor interactions: Effects on meandering wavelength and stiffness

    NASA Astrophysics Data System (ADS)

    Blel, Sonia; Hamouda, Ajmi BH.; Mahjoub, B.; Einstein, T. L.

    2017-02-01

    In this paper we explore the meandering instability of vicinal steps with a kinetic Monte Carlo simulations (kMC) model including the attractive next-nearest-neighbor (NNN) interactions. kMC simulations show that increase of the NNN interaction strength leads to considerable reduction of the meandering wavelength and to weaker dependence of the wavelength on the deposition rate F. The dependences of the meandering wavelength on the temperature and the deposition rate obtained with simulations are in good quantitative agreement with the experimental result on the meandering instability of Cu(0 2 24) [T. Maroutian et al., Phys. Rev. B 64, 165401 (2001), 10.1103/PhysRevB.64.165401]. The effective step stiffness is found to depend not only on the strength of NNN interactions and the Ehrlich-Schwoebel barrier, but also on F. We argue that attractive NNN interactions intensify the incorporation of adatoms at step edges and enhance step roughening. Competition between NNN and nearest-neighbor interactions results in an alternative form of meandering instability which we call "roughening-limited" growth, rather than attachment-detachment-limited growth that governs the Bales-Zangwill instability. The computed effective wavelength and the effective stiffness behave as λeff˜F-q and β˜eff˜F-p , respectively, with q ≈p /2 .

  16. On the statistics of wind turbine wake meandering: An experimental investigation

    NASA Astrophysics Data System (ADS)

    Howard, Kevin B.; Singh, Arvind; Sotiropoulos, Fotis; Guala, Michele

    2015-07-01

    Measurements of the instantaneous wake flow from a model wind turbine placed in a turbulent boundary layer were obtained by wall-parallel oriented particle image velocimetry (PIV) in the St. Anthony Falls Laboratory wind tunnel. PIV velocity vector fields were used to investigate mean (expansion angle, wavelength, and wake velocity) and higher order statistics (local slope, curvature, and correlation) describing meandering motions in the turbine wake. These statistics were used to compare the wakes produced by four different wind turbine operating configurations, which include a single turbine operating at two different tip-speed ratios and two turbines aligned with the mean flow. The origin of meandering motions was identified for all cases in the hub vortex signature, which evolved into a stretched or compressed low speed meander in the wall parallel plane, depending on the turbine operating conditions and on the interaction with the wake shear layer. Finally, both autocorrelation and scale-dependent statistics on the velocity minima fluctuations about the meander signature suggest that small scale vortices, found in the hub shear layer and in the wake shear layer, interact with the hub vortex and govern its spatial evolution into large scale wake meandering.

  17. Optimal precursor of the transition from Kuroshio large meander to straight path

    NASA Astrophysics Data System (ADS)

    Wang, Qiang; Ma, Libin; Xu, Qiangqiang

    2013-09-01

    We used the conditional nonlinear optimal perturbation (CNOP) method to explore the optimal precursor of the transition from Kuroshio large meander (LM) to straight path within a barotropic inflowout-flow model, and found that large amplitudes of the optimal precursor are mainly located in the east of Kyushu, which implies that perturbations in the region are important for the transition from LM to straight path. Furthermore, we investigated the transition processes caused by the optimal precursor, and found that these processes could be divided into three stages. In the first stage, a cyclonic eddy is advected to the formation region of the Kuroshio large meander, which enhances the LM path and causes a cyclonic eddy to shed from the Kuroshio mainstream. This process causes the LM path to change into a small meander path. Subsequently, the small meander is maintained for a period because the vorticity advection is balanced by the beta effect in the second stage. In the third stage, the small meander weakens and the straight path ultimately forms. The positive vorticity advecting downstream is responsible for this process. The exploration of the optimal precursor will conduce to improve the prediction of the transition processes from LM path to straight path, and its spatial structure can be used to guide Kuroshio targeted observation studies.

  18. Imaging beneath the skin of large tropical rivers: Clay controls on system morphodynamics revealed by novel CHIRP sub-surface sonar and deep coring along the Fly and Strickland Rivers, Papua New Guinea (Invited)

    NASA Astrophysics Data System (ADS)

    Aalto, R. E.; Grenfell, M.; Lauer, J. W.

    2010-12-01

    Tropical rivers dominate Earth’s fluvial fluxes for water, carbon, and mineral sediment. They are characterized by large channels and floodplains, old system histories (in comparison to many temperate rivers), frequent and prolonged periods of flooding, and a clay-dominated sediment flux transported above a sandy bed. However, limited insight is available regarding the underlying bed & floodplain strata -- material that underpins system mobility and morphodynamics. Available data commonly stems from “skin-deep” approaches such as GIS analysis of imagery, shallow sampling of a surface veneer, & topographic profiling during lower river stages. Given the large temporal & spatial scales of such systems, new approaches are needed to see below lag deposits on mobile sandy beds & deep into expansive floodbasins. Furthermore, such data are needed to test whether we can usefully interpret large tropical river morphology using direct analogies to observations from small temperate sytems. Systems responding to sea level rise, pending avulsions, or an increase/contrast in sediment load would provide especially valuable insight. We conducted a field campaign along the Fly and Strickland Rivers in Papua New Guinea (discharge ~ 5,400 CMS). Immediate results were obtained using a dual-frequency CHIRP sub-bottom profiler optimized for fluvial environments, with which we were able to image 10-20m below the river/lake bed. We were able to distinguish sandy deposits from harder clay and silt lenses and also collected bed grab samples to verify our sonar results. Deep borehole samples (5-15m), push cores, and cutbank profiles of material strength confirmed observations from the sonar profiling. We simultaneously collected side-scan sonar imagery plus DGPS water/bed elevations. Findings include: 1) The prevalence of hard clay beneath the bed at many locations along the Lower Fly and Strickland Rivers, retarding migration; 2) Unusual bed morphology along the lower Middle Fly River

  19. Response of extratropical cyclone activity to the Kuroshio large meander in northern winter

    NASA Astrophysics Data System (ADS)

    Hayasaki, Masamitsu; Kawamura, Ryuichi; Mori, Masato; Watanabe, Masahiro

    2013-06-01

    We examined possible responses of cyclone activities to the bimodal path states of the Kuroshio Current [i.e., large meander (LM) and non-LM (NLM)] by using the long-term reanalysis data and the 20th century hindcast experiment of a high-resolution atmosphere-ocean coupled model. Compared with a seasonal mean cyclone track frequency for the LM and NLM periods, a primary cyclone track shifts southward in association with the meander of Kuroshio Current. Composite analyses of the hindcast experiment showed remarkable atmospheric responses accompanying the Kuroshio LM. The Kuroshio LM causes a decrease in latent heat flux in the south of Japan and a southward shift of the near-surface baroclinic zone. Distinctive decreases in thermodynamic fluxes inhibit the rapid development of cyclones in the meander region, eventually inducing positive sea level pressure anomalies downstream from that region.

  20. Lake Murray, Fly and Strickland River Basins, Papua, New Guinea

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Lake Murray, a manmade reservoir, lies between the Fly and Strickland River Basins, Papua, New Guinea (7.0S, 141.5E). The region, photographed in sunglint, shows the water level in the reservoir and the full extent of the drainage basins of both river systems as the rivers meander through wide alluvial floodplains. Some forest clearing can be seen in places throughout the region, but most of the area remains in closed canopy forest.

  1. Improved numerical modeling of morphodynamics of rivers with steep banks

    NASA Astrophysics Data System (ADS)

    Langendoen, Eddy J.; Mendoza, Alejandro; Abad, Jorge D.; Tassi, Pablo; Wang, Dongchen; Ata, Riadh; El kadi Abderrezzak, Kamal; Hervouet, Jean-Michel

    2016-07-01

    The flow and sediment transport processes near steep streambanks, which are commonly found in meandering, braided, and anastomosing stream systems, exhibit complex patterns that produce intricate interactions between bed and bank morphologic adjustment. Increasingly, multi-dimensional computer models of riverine morphodynamics are used to aid in the study of these processes. A number of depth-averaged two-dimensional models are available to simulate morphologic adjustment of both bed and banks. Unfortunately, these models use overly simplified conceptual models of riverbank erosion, are limited by inflexible structured mesh systems, or are unable to accurately account for the flow and sediment transport adjacent to streambanks of arbitrary geometry. A new, nonlinear model is introduced that resolves these limitations. The model combines the river morphodynamics computer models TELEMAC-2D and SISYPHE of the open source TELEMAC-MASCARET suite of solvers with the bank erosion modules of the CONCEPTS channel evolution computer model. The performance of the new model is evaluated for meander-planform initiation and development. The most important findings are: (1) the model is able to simulate a much greater variety and complexity in meander wavelengths; (2) simulated meander development agrees closely with the unified bar-bend theory of Tubino and Seminara (1990); and (3) the rate of meander planform adjustment is greatly reduced if the wavelength of alternate bars is similar to that of meanders.

  2. Quantifying Morphologic Changes in a Low Gradient River Crossing Southeast Louisiana Fault Zones

    NASA Astrophysics Data System (ADS)

    Fischer, G.; Gasparini, N. M.; Dawers, N. H.

    2011-12-01

    This study investigates the signature of faulting in low gradient, alluvial rivers crossing the Baton Rouge fault zone (BRFZ) and Denham Springs-Scotlandville fault zone (DSSFZ), which encompass a set of East-West striking normal faults in southeast Louisiana. These faults exhibit surface expressions associated with up to a few meters of vertical displacement of Late Pleistocene sediments, but little is known about their activity during the Holocene. Our study aims to quantify geomorphic changes in a number of rivers that cross these fault zones and to use these changes to gain insight into the history of faulting in the region. We hypothesize that fault movement will be evident in patterns of river sinuosity, slope, and width to depth ratio. We focus on four subparallel channels of various discharges that cross either or both the BRFZ and the DSSFZ. Information on local fault scarp heights and channel reaches are extracted by GIS analysis of the LA LiDAR 5 m DEM, as well as flow modeling using the HEC-RAS software program. On the Tickfaw River, we conducted field surveys using differential GPS to record contemporary water surface slopes and channel location. Historic channel features on the Tickfaw are characterized using a series of aerial photographs dating back to 1952. Over the past 50 years, the Tickfaw River has shortened its course through the study area significantly (~4.9%) by means of meander cutoffs. Since 1952, sinuosity (P) has decreased in all of the Tickfaw channel reaches that cross fault segments. Currently, the sinuosity is extremely low (average P = 1.14) where the river crosses the DSSFZ and slightly higher where the river crosses the BRFZ (average P = 1.9). We use the LiDAR data to quantify offset on the faults that the river crosses. These values will be compared with the average lateral migration rate of the river in order to better understand the time scales over which both processes operate. If the faults appear to have little morphologic

  3. Miniaturized bandpass filter using a meandered stepped-impedance resonator with a meandered-line stub-load on a GaAs substrate.

    PubMed

    Chuluunbaatar, Z; Wang, C; Kim, N Y

    2014-01-01

    This paper reports a compact bandpass filter with improved skirt selectivity using integrated passive device fabrication technology on a GaAs substrate. The structure of the filter consists of electromagnetically coupled meandered-line symmetric stepped-impedance resonators. The strength of the coupling between the resonators is enhanced by using a meandered-line stub-load inside the resonators to improve the selectivity and miniaturize the size of the filter. In addition, the center frequency of the filter can be flexibly controlled by varying degrees of the capacitive coupling between resonator and stub-load. To verify the proposed concept, a protocol bandpass filter with center frequency of 6.53 GHz was designed, fabricated, and measured, with a return loss and insertion loss of 39.1 dB and 1.63 dB.

  4. Electromigration-induced step meandering on vicinal surfaces: Nonlinear evolution equation

    NASA Astrophysics Data System (ADS)

    Dufay, Matthieu; Debierre, Jean-Marc; Frisch, Thomas

    2007-01-01

    We study the effect of a constant electrical field applied on vicinal surfaces such as the Si(111) surface. An electrical field parallel to the steps induces a meandering instability with a nonzero phase shift. Using the Burton-Cabrera-Frank model, we extend the linear stability analysis performed by Liu, Weeks, and Kandel [Phys. Rev. Lett. 81, 2743 (1998)] to the nonlinear regime for which the meandering amplitude is large. We derive an amplitude equation for the step dynamics using a highly nonlinear expansion method. We investigate numerically two limiting regimes (small and large attachment lengths) which both reveal long-time coarsening dynamics.

  5. A numerical investigation of the role of the turbine rotor scale and the nacelle on wake meandering

    NASA Astrophysics Data System (ADS)

    Foti, Daniel; Yang, Xiaolei; Shen, Lian; Sotiropoulos, Fotis

    2016-11-01

    Recent analysis of a hydrokinetic turbine and laboratory scale wind turbine reveal that the turbine nacelle has a considerable effect on the turbulence kinetic energy and wake meandering. However, the role of the nacelle on wake meandering for utility-scale wind turbines has not been fully investigated. In this work, a numerical investigation using large eddy simulations of four wind turbines with rotor diameters ranging from laboratory to utility scale reveals similar turbulent structures in the far wake and a comparable wake meandering Strouhal number regardless of rotor size. By reconstructing the wake meandering with three dimensional spatio-temporal filtering process, first proposed in Foti et al., the statistics of the dynamics of the wake meandering are quantified in terms of amplitude and wavelength. Results indicate that the wavelength of wake meandering can be properly scaled by rotor diameter of the turbines for both simulations with and without a nacelle model. The meandering amplitude, on the other hand, is larger for the simulation with a nacelle. This is further quantitative evidence that a nacelle model is imperative to accurately capturing wake meandering. This work was supported by Department of Energy (DE-EE0002980, DE-EE0005482 and DE-AC04-94AL85000), and Sandia National Laboratories.

  6. Sediment record of polycyclic aromatic hydrocarbons in the Liaohe River Delta wetland, Northeast China: Implications for regional population migration and economic development.

    PubMed

    Ma, Chuanliang; Lin, Tian; Ye, Siyuan; Ding, Xigui; Li, Yuanyuan; Guo, Zhigang

    2017-03-01

    The polycyclic aromatic hydrocarbons (PAHs) of a (210)Pb-dated sediment core extracted from the Liaohe River Delta wetland were measured to reconstruct the sediment record of PAHs and its response to human activity for the past 300 years in Northeast China. The concentrations of the 16 U.S. Environmental Protection Agency priority PAHs (∑16PAHs) ranged from 46 to 1167 ng g(-1) in this sediment core. The concentrations of the 16 PAHs (especially 4- and 5+6-ring PAHs) after the 1980s (surface sediments 0-6 cm) were one or two orders of magnitudes higher than those of the down-core samples. The exponential growth of 4-ring and 5+6-ring PAH concentrations after the 1980s responded well to the increased energy consumption and number of civil vehicles resulting from the rapid economic development in China. Prior to 1950, relatively low levels of the 16 PAHs and a high proportion of 2+3-ring PAHs was indicative of biomass burning as the main source of the PAHs. A significant increase in the 2 + 3 ring PAH concentration from the 1860s-1920s was observed and could be attributed to a constant influx of population migration into Northeast China. It was suggested that the link between historical trend of PAHs and population or energy use involves two different economic stages. Typically, in an agricultural economy, the greater the population size, the greater the emission of PAHs from biomass burning, while in an industrial economy, the increase in sedimentary PAH concentrations is closely related to increasing energy consumption of fossil fuels.

  7. Mobilization of Floodplain Sediments by Chute Cutoffs on a Large River: Lower Wabash River, Illinois-Indiana

    NASA Astrophysics Data System (ADS)

    Zinger, J. A.; Rhoads, B. L.; Best, J.; Engel, F.; Konsoer, K. M.

    2010-12-01

    Bend cutoffs are a common mechanism of morphologic change in all scales of meandering rivers worldwide. Cutoffs can develop either by progressive migration of an elongated bend onto itself, forming a neck cutoff, or by erosion of a new channel across the neck of a bend, producing a chute cutoff. In contrast to the slow processes of “shaving” of the floodplain by outer bank erosion or formation of neck cutoffs by lateral channel migration, the sudden development of a chute cutoff channel can rapidly introduce a large volume of floodplain sediment into the downstream river channel. Formation of a chute cutoff channel also occurs on much shorter timescales than infilling of the subsequent oxbow lake. The asynchronous nature of such floodplain sediment release and storage resulting from cutoffs has important implications for longer-term floodplain sediment balance and the accurate modeling of floodplain evolution and architecture. In this study, using aerial photography and ground survey, we quantified the quantity of floodplain sediment mobilized by two chute cutoff events on Mackey Bend, a large, elongated meander of the lower Wabash River, IL-IN, located just upstream of the Ohio River confluence. A chute cutoff channel on this bend developed during flooding in June 2008 and was followed by formation of a second cutoff channel in July 2009. Here, we compare the volume of sediment released by these cutoff events to the background flux of sediment generated by lateral migration of the bend in the previous 78 years. Our study also explores the influence of these cutoff events on the morphology of the Wabash-Ohio confluence immediately downstream of the evolving chute cutoff channels. We found that, in just over two years, these cutoffs released c. 3. 6 million cubic meters of floodplain sediment, which is comparable to 4.6% of the annual sediment load of the Mississippi River. According to our calculations, it would take over 60 years of lateral migration of Mackey

  8. Diagnosing Meridional Meandering of the Antarctic Circumpolar Current

    NASA Astrophysics Data System (ADS)

    Gille, S. T.; Shao, A.

    2008-12-01

    Long-term warming trends in the Southern Ocean appear consistent with a multi-decadal scale poleward migration of the Antarctic Circumpolar Current (ACC), possibly linked to a long-term shift in the Southern Annular Mode. Since historic in situ hydrographic data are sparse, definitive assessments of the actual trends and mechanisms governing them have proved difficult. Satellite data offer some promise for evaluating the meridional migrations of the ACC. However, studies carried out using microwave sea surface temperature (SST) data as well as satellite altimetry have sometimes reached differing conclusions. In part these differences may stem from the variety of definitions used to locate the frontal jets that define the ACC, which have been based on absolute sea surface height, gradients in sea surface height, or gradients in SST. In addition alternate statistical measures, such as the variance and skewness of sea surface height, have been proposed as means to identify the position of the ACC. This study represents an effort to identify consistent and robust definitions of the ACC jets from satellite altimeter data and to make use of these to investigate the physical processes governing ACC variability.

  9. Structure and Mixing of a Turbulent Meandering Plume Part 2: Turbulent Mixing and Eddy-Diffusivity

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Young, D. L.; Larsson, A. I.

    2016-11-01

    Turbulent mixing in a meandering non-buoyant chemical plume is far less understood than in a straight plume - partially due to the difficulty separating the plume meander fluctuations from the turbulent fluctuations. In this study we present high resolution measurements of the covariance of the turbulent fluctuations of velocity and concentration in a phase-locked meandering plume, acquired by combining simultaneous PTV velocity and LIF concentration measurements. The effectiveness of the eddy-diffusivity model for predicting the turbulent flux is assessed. Analysis of the data reveals that the spatial distribution of the turbulent flux is governed by the large-scale alternating-sign vortices that induce the plume meander. Further, regions of high turbulent flux are co-located with areas of large phase-averaged concentration gradients. As a result, the eddy-diffusivity framework models the turbulent flux effectively. As expected from turbulent mixing theory, the eddy-diffusivity coefficient plateaus at a constant value once the plume width reaches the size of the largest eddies (i.e., the scale of the water depth in this open channel flow). However, when the plume width is less than the water depth the eddy-diffusivity coefficient scales with the plume width to the 3/4 power. This differs from the theoretical 4/3 scaling that results from the assumption of an inertial subrange. The extent of the inertial subrange is extremely limited in the current moderate-Re open channel flow.

  10. Can tide dominance be inferred from the point bar pattern of tidal meandering channels?

    NASA Astrophysics Data System (ADS)

    Tambroni, N.; Luchi, R.; Seminara, G.

    2017-02-01

    We performed 2-D numerical simulations of flow and bed topography in a channel consisting of a sequence of tidal meanders connected to a tidal sea at one end and closed at the other end. Our main goal was to investigate whether the location of point bars relative to the bend apex is correlated with the character of the local flow field, i.e., its flood or ebb dominance. Validation of the model was achieved performing a comparison with results of laboratory observations. Simulations did reproduce the observed evolution of the laterally averaged bed profile toward an equilibrium configuration characterized by the classical landward aggrading trend typical of straight tidal channels with the formation of a shore at the landward end. The presence of meanders led to small amplitude spatial oscillations of the profile on the meander scale. The bar pattern developed when the morphology was far from equilibrium, such that the sediment transport was sufficiently intense to drive significant morphodynamic perturbations. Numerical results did show conclusively that the key factor controlling the phase of the point bar pattern relative to curvature is the flood- or ebb-dominant character of the basic flow field. More precisely, ebb/flood dominance led to point bars located seaward/landward relative to the bend apex. Moreover, two almost symmetrical long lobes that trailed away from the meander apex in both the ebb and flood directions formed in the transition region where the flow field shifts from flood into ebb dominant.

  11. Channel Stability and Water Quality of the Alagnak River, Southwestern Alaska

    USGS Publications Warehouse

    Curran, Janet H.

    2003-01-01

    The Alagnak River, a National Wild River located in southwestern Alaska, drains an area of 3,600 square kilometers and is used for recreational and subsistence activities, primarily angling, camping, rafting, and hunting by visitors and seasonal residents, and for commercial guiding by several lodges. Increases in visitor use in the 1990s included an increase in the use of high-horsepower motorboats on the river, primarily for angling, and raised concerns regarding human impacts on water quality. Downstream from its confluence with the Nonvianuk River at river kilometer (RK) 93, the Alagnak River is formed in glacial drift and outwash with a single, low bedrock outcrop. Analysis of aerial photography from 1951, 1982, and 2001 shows that the river's multiple channels from RK 57 to 93 have been relatively stable. In contrast, long reaches of multiple channels from RK 35 to 57 changed substantially between 1951 and 1982, creating a new complex of channels. Downstream from RK 35, channel changes in the past 50 years consist largely of minor meander migration. Analysis of water samples collected during this study at RK 21, 46, and 93 and in the Alagnak and Nonvianuk Rivers at the outlets of the lakes that form their source shows that the Alagnak River is a nutrient-poor, calcium-bicarbonate water with low suspended-sediment concentrations. Water chemistry changes little over time or in a downstream direction. Weak patterns over time include high late May/early June concentrations of some nutrients, carbon, and iron. Weak patterns over distance include downstream increases in iron, manganese, and phosphorous. No pervasive human impacts on Alagnak River water chemistry were detected. Local effects that could be diluted within a kilometer downstream of the source were not detectable by this study. Data collected at three continuously recording wake gaging stations at RK 21, 46, and 93 showed that 1999-2000 motorboat use was heaviest in the lower reaches of the river

  12. How do big rivers come to be different?

    NASA Astrophysics Data System (ADS)

    Ashworth, Philip J.; Lewin, John

    2012-08-01

    environments are common, with water bodies that vary from smaller water-filled swales and palaeochannels, to floodbasins and km-scale linear lakes in sediment-dammed tributaries. Organic sedimentation is significant along relatively sediment-poor and laterally-stable large rivers that fail to fill their alluvial corridors. Three case studies are used to illustrate this variability in big river pattern and process: the Ob, Jamuna and Paraná. These rivers are respectively dominated by meandering, braiding and mixed mainstream and accessory channel morphologies. Big rivers have some processes and patterns that are different from smaller rivers including: (i) no simple down-valley sequence in control variables and channel pattern, (ii) main channels with high width:depth ratios, (iii) few or no channel-wide unit bars migrating through the main thalwegs, (iv) extensive and low-gradient floodplains that provide space for channel shifting and floodplain sedimentation, (v) long distances between significant tributaries to allow full mixing of water and sediment discharges, (vi) in some places, partially-decoupled channels and floodplains, and (vii) significant floodplain water bodies that readily act as sinks for fine-grained sediment where this is supplied, or organic deposition. Although understanding of contemporary big river patterns requires attention to a range of timescales, including inheritance from sediments of Quaternary age, big rivers do have a distinctive character. The variety of patterns on big rivers may usefully be viewed in terms of sediment systems operating at both the catchment and reach scales. Intra-river variability and internal complexity show the need to understand contrasted sediment supply, through-put and alluvial exchange as determinants of big river morphology and pattern.

  13. Determination of real-time predictors of the wind turbine wake meandering

    NASA Astrophysics Data System (ADS)

    Muller, Yann-Aël; Aubrun, Sandrine; Masson, Christian

    2015-03-01

    The present work proposes an experimental methodology to characterize the unsteady properties of a wind turbine wake, called meandering, and particularly its ability to follow the large-scale motions induced by large turbulent eddies contained in the approach flow. The measurements were made in an atmospheric boundary layer wind tunnel. The wind turbine model is based on the actuator disc concept. One part of the work has been dedicated to the development of a methodology for horizontal wake tracking by mean of a transverse hot wire rake, whose dynamic response is adequate for spectral analysis. Spectral coherence analysis shows that the horizontal position of the wake correlates well with the upstream transverse velocity, especially for wavelength larger than three times the diameter of the disc but less so for smaller scales. Therefore, it is concluded that the wake is actually a rather passive tracer of the large surrounding turbulent structures. The influence of the rotor size and downstream distance on the wake meandering is studied. The fluctuations of the lateral force and the yawing torque affecting the wind turbine model are also measured and correlated with the wake meandering. Two approach flow configurations are then tested: an undisturbed incoming flow (modelled atmospheric boundary layer) and a disturbed incoming flow, with a wind turbine model located upstream. Results showed that the meandering process is amplified by the presence of the upstream wake. It is shown that the coherence between the lateral force fluctuations and the horizontal wake position is significant up to length scales larger than twice the wind turbine model diameter. This leads to the conclusion that the lateral force is a better candidate than the upstream transverse velocity to predict in real time the meandering process, for either undisturbed (wake free) or disturbed incoming atmospheric flows.

  14. Wake meandering statistics of a model wind turbine: Insights gained by large eddy simulations

    NASA Astrophysics Data System (ADS)

    Foti, Daniel; Yang, Xiaolei; Guala, Michele; Sotiropoulos, Fotis

    2016-08-01

    Wind tunnel measurements in the wake of an axial flow miniature wind turbine provide evidence of large-scale motions characteristic of wake meandering [Howard et al., Phys. Fluids 27, 075103 (2015), 10.1063/1.4923334]. A numerical investigation of the wake, using immersed boundary large eddy simulations able to account for all geometrical details of the model wind turbine, is presented here to elucidate the three-dimensional structure of the wake and the mechanisms controlling near and far wake instabilities. Similar to the findings of Kang et al. [Kang et al., J. Fluid Mech. 744, 376 (2014), 10.1017/jfm.2014.82], an energetic coherent helical hub vortex is found to form behind the turbine nacelle, which expands radially outward downstream of the turbine and ultimately interacts with the turbine tip shear layer. Starting from the wake meandering filtering used by Howard et al., a three-dimensional spatiotemporal filtering process is developed to reconstruct a three-dimensional meandering profile in the wake of the turbine. The counterwinding hub vortex undergoes a spiral vortex breakdown and the rotational component of the hub vortex persists downstream, contributing to the rotational direction of the wake meandering. Statistical characteristics of the wake meandering profile, along with triple decomposition of the flow field separating the coherent and incoherent turbulent fluctuations, are used to delineate the near and far wake flow structures and their interactions. In the near wake, the nacelle leads to mostly incoherent turbulence, while in the far wake, turbulent coherent structures, especially the azimuthal velocity component, dominate the flow field.

  15. Kootenai River Fisheries Investigations; Chapter 3 : Mainstem Habitat Use and Recruitment Estimates of Rainbow Trout, 1996 Annual Report.

    SciTech Connect

    Fredericks, James P.; Hendricks, Steve

    1997-09-01

    The objective of this study was to determine if recruitment is limiting the population of rainbow trout Oncorhynchus mykiss in the mainstem Kootenai River. The authors used snorkeling and electrofishing techniques to estimate juvenile rainbow trout density and total numbers in Idaho tributaries, and they trapped juvenile outmigrants to identify the age at which juvenile trout migrate from tributaries to the Kootenai River. The authors radio and reward-tagged post-spawn adult rainbow trout captured in Deep Creek to identify river reach and habitat used by those fish spawning and rearing in the Deep Creek drainage. They also conducted redd surveys in the Kootenai River to determine the extent of mainstem spawning. Based on the amount of available habitat and juvenile rainbow trout densities, the Deep Creek drainage was the most important area for juvenile production. Population estimates of age 0, age 1+, and age 2+ rainbow trout indicated moderate to high densities in several streams in the Deep Creek drainage whereas other streams, such as Deep Creek, had very low densities of juvenile trout. The total number of age 0, age 1+, and age 2+ rainbow trout in Deep Creek drainage in 1996 was estimated to be 63,743, 12,095, and 3,095, respectively. Radio telemetry efforts were hindered by the limited range of the transmitters, but movements of a radio-tagged trout and a returned reward tag indicated that at least a portion of the trout utilizing the Deep Creek drainage migrated downriver from the mouth of Deep Creek to the meandering section of river. They found no evidence of mainstem spawning by rainbow trout, but redd counting efforts were hindered by high flows from mid-April through June.

  16. Influence of Large Woody Debris on Three-dimensional Flow Structure Through Meander Bends in a Low-energy Stream

    NASA Astrophysics Data System (ADS)

    Newell, M. D.; Rhoads, B. L.

    2001-05-01

    Most theoretical research on the dynamics of meandering streams has emphasized the importance of internal mechanisms. Although there is an abundance of empirical work on external factors, theoretical development in this area has been limited, especially for biotic factors, such as LWD, which geomorphologists have long recognized constitute important external mechanisms in fluvial systems. In particular, little is known about the role of LWD in low-energy, human-modified streams. One important potential morphological influence of LWD that has not been investigated is the potential for LWD to alter flow structures through meander bends, a critical element of current meander evolution theories since three dimensional characteristics of flow through meander bends have been shown to have a significant impact on the processes of sediment transport and bank erosion, and consequently meander development. The overall goal of this project is to advance the understanding of the interactions between large woody debris and the geomorphic structure and function of low-gradient meandering streams. This improved understanding will provide a more reliable framework of knowledge on which to base stream naturalization (i.e. the return to pre-disturbance conditions) and management plans for low-energy meandering streams with abundant LWD.

  17. From River Rambles to Museum Meanderings: Student Motivation and Service Learning.

    ERIC Educational Resources Information Center

    Elmer, Denise

    The prominence of experiential learning or service learning continues to grow in higher education. A 1999-2000 survey found that of 324 universities and colleges across the United States, 82% offer over 7,000 undergraduate level courses and over 700 graduate level courses in experiential or service learning. This paper considers the role of…

  18. Assessing fish predation on migrating juvenile steelhead and a retrospective comparison to steelhead survival through the Priest Rapids Hydroelectric Project, Columbia River, Washington, 2009-11

    USGS Publications Warehouse

    Hardiman, Jill M.; Counihan, Timothy D.; Burgess, Dave S.; Simmons, Katrina E.; Holmberg, Glen S.; Rogala, Josh; Polacek, Rochelle

    2012-01-01

    The U.S. Geological Survey (USGS) and the Washington Department of Fish and Wildlife (WDFW) have been working with the Public Utility District No. 2 of Grant County, Washington (Grant PUD), to increase their understanding of predator-prey interactions in the Priest Rapids Hydroelectric Project (PRP), Columbia River, Washington. For this study, the PRP is defined as the area approximately 6 kilometers upstream of Wanapum Dam to the Priest Rapids Dam tailrace, 397.1 miles from the mouth of the Columbia River. Past year’s low survival numbers of juvenile steelhead (Oncorhynchus mykiss) through Wanapum and Priest Rapids Dams has prompted Grant PUD, on behalf of the Priest Rapids Coordinating Committee, to focus research efforts on steelhead migration and potential causal mechanisms for low survival. Steelhead passage survival in 2009 was estimated at 0.944 through the Wanapum Development (dam and reservoir) and 0.881 through the Priest Rapids Development and for 2010, steelhead survival was 0.855 for Wanapum Development and 0.904 for Priest Rapids Development. The USGS and WDFW implemented field collection efforts in 2011 for northern pikeminnow (Ptychocheilus oregonensis), smallmouth bass (Micropterus dolomieu), and walleye (Sander vitreus, formerly Stizostedion vitreum) and their diets in the PRP. For predator indexing, we collected 948 northern pikeminnow, 237 smallmouth bass, 18 walleye, and two largemouth bass (Micropterus salmoides). The intent of this study was to provide standardized predation indices within individual reaches of the PRP to discern spatial variability in predation patterns. Furthermore, the results of the 2011 study were compared to results of a concurrent steelhead survival study. Our results do not indicate excessively high predation of Oncorhynchus spp. occurring by northern pikeminnow or smallmouth bass in any particular reach throughout the study area. Although we found Oncorhynchus spp. in the predator diets, the relative

  19. Assessment of dam impacts on sediment dynamics and channel geometry in complex anthropogenic systems: feedbacks from comparative study of the Sacramento and the Ain Rivers

    NASA Astrophysics Data System (ADS)

    Rollet, A. J.; Piégay, H.; Michalkova, M.; Kondolf, G. M.

    2009-04-01

    Numerous studies have demonstrated the complexity of river adjustments downstream dams (Williams and Wolman, 1984; Brandt, 2000; Petts and Gurnell, 2005), depending on many parameters such catchment geology context (Grant et al., 2003), land use, pre-dam sediment supply and transport regime, degree of hydrologic alteration (Church, 1995; Schmidt and Wilcock, 2008), and dam characteristics and operation (Brewer and Lewin, 1998). Dam impact is particularly difficult to evaluate in river systems where human pressures are old and manifold, and where dam-induced impacts can be compounded by other human influences, such as in-channel aggregate mining (Kondolf 1997). In such cases, it may be challenging to sort out the causal links between dam-induced disruptions and resulting channel adjustment. To illustrate these problems, we introduce two complex case studies, the Ain (France) and Sacramento (California) Rivers, both freely meandering rivers regulated since mid-20th century, whose sedimentary and morphologic dynamic have been modified in different ways since the end of the 19th century. Dam impacts can be distinguished from the effects of other factors such as floodplain disconnection by flood-control infrastructure, land-use changes, and artificial meander-bend cutoff. The Ain River evinces a significant sediment deficit, which results in bed degradation, decrease in area of gravel bars , and reduced lateral channel migration. As a result, sediment supply is reduced not only from trapping by upstream reservoirs but also by reduced bank erosion. In the case of the Sacramento, the impact of the dam is not as clear as on the Ain due to major effects of prior pressures on the channel. Using aerial imagery and field measurements (grain-size measurements…), we led a spatiotemporal study of several morphologic parameters (active channel narrowing, gravel bar areas …) to underline the relative contribution of dams to the contemporary channel evolution. These analyses are

  20. The Lowland Rivers of The Netherlands - Geodiversity and Cultural Heritage on 19th and early 20th century Landscape Paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter Dirk; van den Ancker, Hanneke; Moes, Constance

    2015-04-01

    One of the major Dutch landscapes is formed by lowland rivers. They divide the country in a southern and a northern part, both physically and culturally. We screened the freely available database of 19th and early 20th century paintings of Simonis & Buunk, www.simonis-buunk.com, looking for lowland river landscapes depicting geodiversity and cultural heritage relationships (See References for other landscapes). Emperor Napoleon declared The Netherlands as naturally belonging to his empire as its lands originated from muds originating in France and transported there by the big rivers. A description that may have given rise to the idea of the Netherlands as a delta, but from a geomorphological perspective The Netherlands consists of series of river plains of terrestrial origin, of which the north-western part are subsiding and invaded by the sea. Now, the rivers Meuse and Rhine (including its branches Waal and IJssel) meander through ever larger river plains before reaching the North Sea. They end in estuaries, something one would not expect of rivers with catchments discharging a large part of Western Europe. Apart from the geological subsidence, the estuaries might be due to human interference, the exploitation of peat and building of dikes since the 11th century, heavy storms and the strong tidal currents. Archaeological finds show Vikings and Romans already used the river Rhine system for trading and transporting goods. During the Roman Empire the Rhine was part of The Limes, the northern defence line of the empire. Romans already influenced the distribution of water over the different river branches. Since the middle of the 19th century groins and canalization drastically changed the character of the rivers. The 19th and early 20th century landscape paintings illustrate this change as well as changes in land use. Examples of geodiversity and cultural heritage relationships shown: - meanders and irregular banks disappear as river management increases, i.a. bends

  1. Analysis of multiple wavelengths of Lamb waves generated by meander-line coil EMATs.

    PubMed

    Zhai, Guofu; Jiang, Tao; Kang, Lei

    2014-02-01

    The electromagnetic acoustic transducers (EMATs) with a meander-line coil possess the capability of generating Lamb waves carrying multiple wavelengths, and the characteristics of multiple wavelengths is analyzed by developing a spatial transversal filter model for the EMAT. It is shown that the characteristics is due to the wavelength spectrum of the EMATs, which is a wavelength-domain representation of information about the wavelength components, and the magnitude of each components is modulated by an envelope which depends on the geometric pattern of the meander-line coil. The characteristics of multiple wavelengths might cause the multi-modes phenomenon, therefore a method for removing the effect of multiple wavelengths is proposed. It is shown that the effect can be removed by designing an EMAT which can produce a special envelop to suppress the harmonic wavelengths. Experiments are set up to study the characteristics of multiple wavelengths and verify the validity of the proposed method.

  2. Dielectric-based subwavelength metallic meanders for wide-angle band absorbers.

    PubMed

    Shen, Su; Qiao, Wen; Ye, Yan; Zhou, Yun; Chen, Linsen

    2015-01-26

    We propose nano-meanders that can achieve wide-angle band absorption in visible regime. The nano-meander consists of a subwavelength dielectric grating covered by continuous ultra-thin Aluminum film (less than one tenth of the incident wavelength). The excited photonic resonant modes, such as cavity mode, surface plasmonic mode and Rayleigh-Wood anomaly, are discussed in detail. Nearly total resonant absorption due to funneling mechanism in the air nano-groove is almost invariant with large incident angle in transverse magnetic polarization. From both the structural geometry and the nanofabrication point of view, the light absorber has a very simple geometrical structure and it is easy to be integrated into complex photonic devices. The highly efficient angle-robust light absorber can be potential candidate for a range of passive and active photonic applications, including solar-energy harvesting as well as producing artificial colors on a large scale substrate.

  3. The effect of floodplain grass on the flow characteristics of meandering compound channels

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Shan, Yuqi; Liu, Xingnian; Yang, Kejun; Liao, Huasheng

    2016-11-01

    Laboratory experiments were conducted in a large-scale meandering compound channel to investigate the effect of floodplain grass on the main flow field in the channel. Three-dimensional velocity fields, turbulences, and Reynolds shear stresses were measured along half a meander. The experiments revealed that flexible artificial grass planted on a floodplain can significantly reduce the conveyance capability of the entire channel. Two parallel stage-discharge curves increased with increasing flow depth. The additional resistance of the floodplain grass increased the streamwise velocity and conveyance in the main channel along a meander. An analysis of the generation mechanism of secondary flows in the main channel indicated that the secondary current consisted of an enhanced original secondary cell that was strengthened by the centrifugal force and a component of the upstream floodplain flow. The relative dominance of these two components in the secondary flows was primarily determined by the angle between the floodplain flow and the main channel ridge, and also the floodplain roughness. At the same flow depth, the secondary flow in cases with grass on the floodplain was generally stronger than that in the case of a smooth meander bend, although it was weaker near the middle cross-over section. Floodplain grass enhanced the intensity of the lateral turbulence above the bankfull level and significantly modified the turbulence structure, although it had a negligible effect on the vertical turbulence except at the bend entrance. Floodplain grass also affected the Reynolds shear stresses in the main channel, generating stronger lateral shear stresses at a low flow depth. In contrast, at a high flow depth, the distribution of the interface shear stresses changed entirely while its magnitude remained the same. When the floodplains were grassed, the vertical shear stress that was induced by secondary flows was greater at the apexes but reduced at the cross-over sections

  4. A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota.

    PubMed

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability/ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes) on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact research as well as

  5. Geomorphic changes resulting from floods in reconfigured gravel-bed river channels in Colorado, USA

    USGS Publications Warehouse

    Elliott, J.G.; Capesius, J.P.

    2009-01-01

    Geomorphic changes in reconfi gured reaches of three Colorado rivers in response to floods in 2005 provide a benchmark for "restoration" assessment. Sedimententrainment potential is expressed as the ratio of the shear stress from the 2 yr, 5 yr, 10 yr, and 2005 floods to the critical shear stress for sediment. Some observed response was explained by the excess of flood shear stress relative to the resisting force of the sediment. Bed-load entrainment in the Uncompahgre River and the North Fork Gunnison River, during 4 and 6 yr floods respectively, resulted in streambed scour, streambed deposition, lateral-bar accretion, and channel migration at various locations. Some constructed boulder and log structures failed because of high rates of bank erosion or bed-material deposition. The Lake Fork showed little or no net change after the 2005 flood; however, this channel had not conveyed floods greater than the 2.5 yr flood since reconfi guration. Channel slope and the 2 yr flood, a surrogate for bankfull discharge, from all three reconfi gured reaches plotted above the Leopold and Wolman channel-pattern threshold in the "braided channel" region, indicating that braiding, rather than a single-thread meandering channel, and midchannel bar formation may be the natural tendency of these gravel-bed reaches. When plotted against a total stream-power and median-sediment-size threshold for the 2 yr flood, however, the Lake Fork plotted in the "single-thread channel" region, the North Fork Gunnison plotted in the " multiplethread" region, and the Uncompahgre River plotted on the threshold. All three rivers plotted in the multiple-thread region for floods of 5 yr recurrence or greater. ?? 2009 Geological Society of America.

  6. A Modelling Framework to Assess the Effect of Pressures on River Abiotic Habitat Conditions and Biota

    PubMed Central

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a modelling framework was further developed and tested to assess the effect of pressures at different spatial scales on reach-scale habitat conditions and biota. Ecohydrological and 1D hydrodynamic models were used to predict discharge and water quality at the catchment scale and the resulting water level at the downstream end of a study reach. Long-term reach morphology was modelled using empirical regime equations, meander migration and 2D morphodynamic models. The respective flow and substrate conditions in the study reach were predicted using a 2D hydrodynamic model, and the suitability of these habitats was assessed with novel habitat models. In addition, dispersal models for fish and macroinvertebrates were developed to assess the re-colonization potential and to finally compare habitat suitability and the availability / ability of species to colonize these habitats. Applicability was tested and model performance was assessed by comparing observed and predicted conditions in the lowland Treene River in northern Germany. Technically, it was possible to link the different models, but future applications would benefit from the development of open source software for all modelling steps to enable fully automated model runs. Future research needs concern the physical modelling of long-term morphodynamics, feedback of biota (e.g., macrophytes) on abiotic habitat conditions, species interactions, and empirical data on the hydraulic habitat suitability and dispersal abilities of macroinvertebrates. The modelling framework is flexible and allows for including additional models and investigating different research and management questions, e.g., in climate impact research as well

  7. Scroll wave meandering induced by phase difference in a three-dimensional excitable medium.

    PubMed

    Yang, Zhao; Gao, Shiyuan; Ouyang, Qi; Wang, Hongli

    2012-11-01

    We investigated scroll waves in an inhomogeneous excitable 3D system with gradient of excitability. The gradient promotes twisting of the scroll waves. Sufficiently large excitability gradient enhances the twisting and causes simple scroll waves to transition to meandering scroll waves. For the twist-induced instability of scroll waves, we analyzed the stability of 2D spiral waves sliced from the twisted scroll in the vertical direction. The 3D problem is simplified by taking into account the diffusive coupling in the third direction as a time-delayed perturbation to the 2D spiral wave. An additional "negative mass" term measuring the twist thus arises in the 2D system and induces the transition from simple rotation to meandering. A further increase in the gradient ruins partially the unity of the meandering scrolls and generates semiturbulence, the analogs of which were observed in the Belousov-Zhabotinski reaction. We also generated the phase diagram in the parameter space by adjusting the threshold for excitation of the media.

  8. Archaeological Survey and Testing for the Upstream Work. Big Stone Lake-Whetstone River Project Area,

    DTIC Science & Technology

    1975-09-01

    Minnesota River valley between Ortonville and Big Stone City is the beginning point of Glacial River Warren which drained both Lake Agassiz I and...Lake Agassiz II in the terminal and early post-glacial Pleistocene. The valley is very wide and deep for its entire length, reflecting the huge...very small remnant of Glacial Lake Agassiz . Big Stone Lake has very little discharge and the upper Minnesota River is a small stream meandering over a

  9. Power law time dependence of river flood decay and its relationship to long term discharge frequency distribution. [California

    NASA Technical Reports Server (NTRS)

    Schubert, G.; Lingenfelter, R. E.

    1973-01-01

    Investigations have continued into the possibility that significant information on stream flow rates can be obtained from aerial and satellite imagery of river meander patterns by seeking a correlation between the meander and discharge spectra of rivers. Such a correlation could provide the basis for a simple and inexpensive technique for remote sensing of the water resources of large geographical areas, eliminating the need for much hydrologic recording. The investigation of the nature of the meander and discharge spectra and their interrelationship can also contribute to a more fundamental understanding of the processes of both river meander formation and drainage of large basins. It has been found that floods decay with an inverse power law dependence on time. The exponent of this dependence varies from river to river and even from station to station along the same river. This power law time dependence makes possible the forecasting of river discharge with an uncertainty of about 5% for as long as a month following the flood peak.

  10. Denitrification in the Mississippi River network controlled by flow through river bedforms

    USGS Publications Warehouse

    Gomez-Velez, Jesus D.; Harvey, Judson W.; Cardenas, M. Bayani; Kiel, Brian

    2015-01-01

    Increasing nitrogen concentrations in the world’s major rivers have led to over-fertilization of sensitive downstream waters1, 2, 3, 4. Flow through channel bed and bank sediments acts to remove riverine nitrogen through microbe-mediated denitrification reactions5, 6, 7, 8, 9, 10. However, little is understood about where in the channel network this biophysical process is most efficient, why certain channels are more effective nitrogen reactors, and how management practices can enhance the removal of nitrogen in regions where water circulates through sediment and mixes with groundwater - hyporheic zones8, 11, 12. Here we present numerical simulations of hyporheic flow and denitrification throughout the Mississippi River network using a hydrogeomorphic model. We find that vertical exchange with sediments beneath the riverbed in hyporheic zones, driven by submerged bedforms, has denitrification potential that far exceeds lateral hyporheic exchange with sediments alongside river channels, driven by river bars and meandering banks. We propose that geomorphic differences along river corridors can explain why denitrification efficiency varies between basins in the Mississippi River network. Our findings suggest that promoting the development of permeable bedforms at the streambed - and thus vertical hyporheic exchange - would be more effective at enhancing river denitrification in large river basins than promoting lateral exchange through induced channel meandering

  11. Denitrification in the Mississippi River network controlled by flow through river bedforms

    USGS Publications Warehouse

    Gomez-Velez, Jesus D.; Harvey, Judson W.; Cardenas, M. Bayani; Kiel, Brian

    2015-01-01

    Increasing nitrogen concentrations in the world’s major rivers have led to over-fertilization of sensitive downstream waters1, 2, 3, 4. Flow through channel bed and bank sediments acts to remove riverine nitrogen through microbe-mediated denitrification reactions5, 6, 7, 8, 9, 10. However, little is understood about where in the channel network this biophysical process is most efficient, why certain channels are more effective nitrogen reactors, and how management practices can enhance the removal of nitrogen in regions where water circulates through sediment and mixes with groundwater - hyporheic zones8, 11, 12. Here we present numerical simulations of hyporheic flow and denitrification throughout the Mississippi River network using a hydrogeomorphic model. We find that vertical exchange with sediments beneath the riverbed in hyporheic zones, driven by submerged bedforms, has denitrification potential that far exceeds lateral hyporheic exchange with sediments alongside river channels, driven by river bars and meandering banks. We propose that geomorphic differences along river corridors can explain why denitrification efficiency varies between basins in the Mississippi River network. Our findings suggest that promoting the development of permeable bedforms at the streambed - and thus vertical hyporheic exchange - would be more effective at enhancing river denitrification in large river basins than promoting lateral exchange through induced channel meandering.

  12. Denitrification in the Mississippi River network controlled by flow through river bedforms

    NASA Astrophysics Data System (ADS)

    Gomez-Velez, Jesus D.; Harvey, Judson W.; Cardenas, M. Bayani; Kiel, Brian

    2015-12-01

    Increasing nitrogen concentrations in the world's major rivers have led to over-fertilization of sensitive downstream waters. Flow through channel bed and bank sediments acts to remove riverine nitrogen through microbe-mediated denitrification reactions. However, little is understood about where in the channel network this biophysical process is most efficient, why certain channels are more effective nitrogen reactors, and how management practices can enhance the removal of nitrogen in regions where water circulates through sediment and mixes with groundwater--hyporheic zones. Here we present numerical simulations of hyporheic flow and denitrification throughout the Mississippi River network using a hydrogeomorphic model. We find that vertical exchange with sediments beneath the riverbed in hyporheic zones, driven by submerged bedforms, has denitrification potential that far exceeds lateral hyporheic exchange with sediments alongside river channels, driven by river bars and meandering banks. We propose that geomorphic differences along river corridors can explain why denitrification efficiency varies between basins in the Mississippi River network. Our findings suggest that promoting the development of permeable bedforms at the streambed--and thus vertical hyporheic exchange--would be more effective at enhancing river denitrification in large river basins than promoting lateral exchange through induced channel meandering.

  13. Man versus Rivers: the lost equilibrium of the Tisza River due to engineering works

    NASA Astrophysics Data System (ADS)

    Kiss, Timea; Fiala, Károly

    2016-04-01

    The direct and indirect human impacts alter the catchment and the channel characteristics, which will result in further hydro-morphological alterations of rivers. The modified fluvial environment will create new hydrological hazards for the society, so for the successful and sustainable hazard and risk management it is important to evaluate the equilibrium and sensitivity of rivers. The aim of the paper is to evaluate the hydrological and morphological effects of engineering works along the Tisza River, Hungary. Based on the trends of the different fluvial processes the equilibrium of the river will be evaluated to ground further engineering works. The Tisza River, was one of the first systematically regulated rivers in Europe. In the late 19th century artificial cut-offs were made, shortening the river by ca. 30%. The hydrology and the morphology of the Tisza adapted to this, as the channel became temporarily wider and deeper (by 20-25%). The cut-offs had an effect on the channel for ca. 60-70 years. Simultaneously, artificial levees were built, thus the overbank floodplain aggradation became more intensive (from 0.02-0.07 cm/y to 0.3-0.8 mm/y). The floodplain aggradation became higher by 2-4 times since 1970's, as the vegetation became denser. However, in the 21st c. the floodplain vegetation became so uncontrollably dense, that the pattern and rate of accumulation changed again, and now it is limited just to the banks. So the levee could be considered as continuous disturbing factor, besides, the unmanaged floodplain vegetation appeared as a new disturbing force accelerating the processes. In the 20th century revetments were constructed to stop the lateral migration of the channel. This resulted in channel distortion, as it became sharper and the cross-sectional area decreased by 28%. As revetments were constructed along ca. 51% of the channel, the meandering channel forms became replaced features characteristic in incising rivers, for example point

  14. Spatial-temporal fluvial morphology analysis in the Quelite river: It's impact on communication systems

    NASA Astrophysics Data System (ADS)

    Ramos, Judith; Gracia, Jesús

    2012-01-01

    SummaryDuring 2008 and 2009 heavy rainfall took place around the Mazatlan County in the Sinaloa state, Mexico, with a return period (Tr) between 50 and 100 years. As a result, the region and its infrastructure, such as the railways and highways (designed for a Tr = 20 years) were severely exposed to floods and, as a consequence damage caused by debris and sediments dragged into the channel. One of the highest levels of damage to the infrastructure was observed in the columns of Quelite River railway's bridge. This is catastrophic as the railway is very important for trade within the state and also among other states in Mexico and in the USA. In order to understand the impact of the flooding and to avoid the rail system being damaged it is necessary to analyse how significant the changes in the river channel have been. This analysis looks at the definition of the main channel and its floodplain as a result of the sediment variability, not only at the bridge area, but also upstream and downstream. The Quelite River study considers the integration of Geographic Information Systems (GIS) and remote sensing data to map, recognise and assess the spatio-temporal change channel morphology. This increases the effectiveness of using different types of geospatial data with in situ measurements such as hydrological data. Thus, this paper is an assessment of a 20 years study period carried out using historical Landsat images and aerial photographs as well as recent Spot images. A Digital Elevation Model (DEM) of local topography and flow volumes were also used. The results show the Quelite River is an active river with a high suspended sediment load and migration of meanders associated to heavy rainfall. The river also has several deep alluvial floodplain channels which modified the geometry and other morphological characteristics of the channel in the downstream direction. After the identification of the channel changes, their causes and solutions to control, the channel

  15. Cell Migration

    PubMed Central

    Trepat, Xavier; Chen, Zaozao; Jacobson, Ken

    2015-01-01

    Cell migration is fundamental to establishing and maintaining the proper organization of multicellular organisms. Morphogenesis can be viewed as a consequence, in part, of cell locomotion, from large-scale migrations of epithelial sheets during gastrulation, to the movement of individual cells during development of the nervous system. In an adult organism, cell migration is essential for proper immune response, wound repair, and tissue homeostasis, while aberrant cell migration is found in various pathologies. Indeed, as our knowledge of migration increases, we can look forward to, for example, abating the spread of highly malignant cancer cells, retarding the invasion of white cells in the inflammatory process, or enhancing the healing of wounds. This article is organized in two main sections. The first section is devoted to the single-cell migrating in isolation such as occurs when leukocytes migrate during the immune response or when fibroblasts squeeze through connective tissue. The second section is devoted to cells collectively migrating as part of multicellular clusters or sheets. This second type of migration is prevalent in development, wound healing, and in some forms of cancer metastasis. PMID:23720251

  16. Genetic characteristics and migration history of a bronze culture population in the West Liao-River valley revealed by ancient DNA.

    PubMed

    Li, Hongjie; Zhao, Xin; Zhao, Yongbin; Li, Chunxiang; Si, Dayong; Zhou, Hui; Cui, Yinqiu

    2011-12-01

    In order to study the genetic characteristics of the Lower Xiajiadian culture (LXC) population, a main bronze culture branch in northern China dated 4500-3500 years ago, two uniparentally inherited markers, mitochondrial DNA and Y-chromosome single-nucleotide polymorphisms (Y-SNPs), were analyzed on 14 human remains excavated from the Dadianzi site. The 14 sequences, which contained 13 haplotypes, were assigned to 9 haplogroups, and Y-SNP typing of 5 male individuals assigned them to haplogroups N (M231) and O3 (M122). The results indicate that the LXC population mainly included people carrying haplogroups from northern Asia who had lived in this region since the Neolithic period, as well as genetic evidence of immigration from the Central Plain. Later in the Bronze Age, part of the population migrated to the south away from a cooler climate, which ultimately influenced the gene pool in the Central Plain. Thus, climate change is an important factor, which drove the population migration during the Bronze Age in northern China. Based on these results, the local genetic continuity did not seem to be affected by outward migration, although more data are needed especially from other ancient populations to determine the influence of return migration on genetic continuity.

  17. Distribution, migration behavior, habitat use, and species interactions of fall-released juvenile hatchery spring Chinook salmon in the Deschutes River, Oregon, 2003

    USGS Publications Warehouse

    Reagan, R.E.; Adams, N.S.; Rondorf, D.W.; Fitzgerald, G.; Spateholts, R.; Hoffman, T.; Olson, D.E.

    2005-01-01

    In a review of National Fish Hatcheries (NFH), the U.S. Fish and Wildlife Service (USFWS) identified the need to assess the fate of hatchery-reared fish and their potential effect on the aquatic community (USFWS 1998). Additionally, the National Marine Fisheries Service (NMFS) recommended monitoring and evaluating ecological interactions between hatchery and wild fish (NMFS 1999; Columbia River Biological Opinion). In 2003, a study was designed to investigate the fate of hatchery-reared fish and to assess habitat use and fish interactions in the Deschutes River, Oregon.

  18. Recent (circa 1998 to 2011) channel-migration rates of selected streams in Indiana

    USGS Publications Warehouse

    Robinson, Bret A.

    2013-01-01

    An investigation was completed to document recent (circa 1998 to 2011) channel-migration rates at 970 meander bends along 38 of the largest streams in Indiana. Data collection was completed by using the Google Earth™ platform and, for each selected site, identifying two images with capture dates separated by multiple years. Within each image, the position of the meander-bend cutbank was measured relative to a fixed local landscape feature visible in both images, and an average channel-migration rate was calculated at the point of maximum cutbank displacement. From these data it was determined that 65 percent of the measured sites have recently been migrating at a rate less than 1 ft/yr, 75 percent of the sites have been migrating at a rate less than 10 ft/yr, and while some sites are migrating in excess of 20 ft/yr, these occurrences are rare. In addition, it is shown that recent channel-migration activity is not evenly distributed across Indiana. For the stream reaches studied, far northern and much of far southern Indiana are drained by streams that recently have been relatively stationary. At the same time, this study shows that most of the largest streams in west-central Indiana and many of the largest streams in east-central Indiana have shown significant channel-migration activity during the recent past. It is anticipated that these results will support several fluvial-erosion-hazard mitigation activities currently being undertaken in Indiana.

  19. Coastal upwelling on the far eastern Agulhas Bank associated with large meanders in the Agulhas Current

    NASA Astrophysics Data System (ADS)

    Goschen, W. S.; Bornman, T. G.; Deyzel, S. H. P.; Schumann, E. H.

    2015-06-01

    Six large solitary meanders in the Agulhas Current, so-called Natal Pulses, propagated down the eastern coast of South Africa between 2009 and 2011. Their influence on the coastal waters between Port Alfred and Algoa Bay, on the far eastern Agulhas Bank, was measured by thermistor strings moored at 30-80 m bottom depths and two current metres (30 m bottom depth) located at both sides of Algoa Bay. During all events active upwelling lasting 1-3 weeks was observed over the inner shelf and in Algoa Bay. During upwelling the isotherms ascended at an average rate of 1.8 m day-1 as the cold bottom layer increased in thickness to 40-60 m, although upwelled water did not break the surface in all cases. Cold water remained in the area for a further 2-3 weeks. During three Natal Pulses the water temperatures at the outer moorings initially increased as the plume of the leading edge (crest) of the meander moved onshore. During one Natal Pulse upwelling was recorded before the warm water plume impacted the moorings. At the onset of upwelling currents switched to the southwest in the case of Bird Island and southward at the Cape Recife inner-bay site and reached a maximum speed of 80 cm s-1. During all Natal Pulses cold bottom water (10-12 °C) flooded over the 80 m bottom depth moorings as the crest of the meander moved onshore, but also around the same time the core of the Agulhas Current began to move offshore. In all cases upwelling was wide-spread.

  20. Anabranching Channel Patterns: the Kingdom of Large Alluvial Rivers

    NASA Astrophysics Data System (ADS)

    Latrubesse, Edgardo

    2015-04-01

    For a long time anabranching patterns were primarily restricted to "exotic and remote" zones in arid systems such as Australia. For that reason, they were not accepted as a major topic of discussion in our discipline, which was based on concepts principally derived from case studies in braided and meandering rivers of the Northern Hemisphere. However, anabranching alluvial patterns are widespread in a variety of environments and scales, from arid small rivers to alluvial reaches of giant rivers such as the Amazon, Congo, and Negro. The largest rivers of the world in water discharge are anabranching, and the majority of the forty-five largest rivers (water discharges >5000m3s-1) are dominantly anabranching systems. Only a small number of rivers with meandering patterns, or sinuous with branches (meandering-tendency to anabranch) are part of the largest rivers group. The present large anabranching rivers flowing on lowlands and well developed floodplains have in common a characteristic very slow slopes, specific stream power of < 25 Wm-2 and sandy bed load with sand sizes dominantly ranging from 0.1 < D50 <0.5 mm. The diversity of planforms and island morphologies in large anabranching rivers result from autogenic adjustments to millennial scales in broad valleys and to century-decadal scale channel-floodplain processes. The variety of anabranching styles are not specifically related to a single explanatory "physically based theory" but to a variety of morphological processes, complex-channel floodplain interactions and the geologic characteristics of the valleys. Once considered a kind of oddity, anabranching rivers must be considered major and fundamental representatives of the fluvial world.

  1. HF Meander-Line Antenna Simulations and Investigations for NVIS on a HMMV

    DTIC Science & Technology

    2016-09-28

    from   Radio  Frequency  Identification  ( RFID )  to  WLAN  communication  systems  [1]-­‐  [3].   Typical  planar...Herraiz-­‐Martinez,  F.  Martin  and  J.  Bonache,  "Dual-­‐ Band  UHF-­‐ RFID  Tags  Based  on  Meander-­‐Line  Antennas

  2. Defect images by planar ECT probe of meander-mesh coils

    SciTech Connect

    Yamada, Sotoshi; Katou, Masaki; Iwahara, Masayoshi; Dawson, F.P.

    1996-09-01

    This paper presents results pertaining to image data obtained from a planar meander-mesh coupled coil type ECT probe. The image data makes it possible to detect not only the existence of a defect but also to extract detailed information regarding the nature of the defect, such as its position, shape, length, and direction. In order to recognize a defect distinctly, the authors have fabricated the high sensitive planar coil which can be used to image a 2-D representation of the ECT signal. The relationships between the image pattern and defect shape are discussed.

  3. Design and simulation of MEMS vector hydrophone with reduced cross section based meander beams

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Dutta, S.; Pal, Ramjay; Jain, K. K.; Gupta, Sudha; Bhan, R. K.

    2016-04-01

    MEMS based vector hydrophone is being one of the key device in the underwater communications. In this paper, we presented a bio-inspired MEMS vector hydrophone. The hydrophone structure consists of a proof mass suspended by four meander type beams with reduced cross-section. Modal patterns of the structure were studied. First three modal frequencies of the hydrophone structure were found to be 420 Hz, 420 Hz and 1646 Hz respectively. The deflection and stress of the hydrophone is found have linear behavior in the 1 µPa - 1Pa pressure range.

  4. Genetic differences between hatchery and wild steelhead for growth and survival in the hatchery and seaward migration after release (Study sites: Dworshak Hatchery and Clearwater Hatchery; Stocks: Dworshak hatchery and Selway River wild; Year classes: 1994 and 1995): Chapter 2

    USGS Publications Warehouse

    Rubin, Stephen P.; Reisenbichler, Reginald R.; Hensleigh, Jay E.; Wetzel, Lisa A.; Baker, Bruce M.; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

    2012-01-01

    Various studies suggest that sea ranching of anadromous salmonids can result in domestication (increased fitness in the hatchery program) and a loss of fitness for natural production; however, the mechanism has not been characterized adequately. We artificially spawned hatchery and wild steelhead Oncorhynchus mykiss from the Clearwater River, Idaho, reared the resulting genetically marked (at the PEPA allozyme locus) progeny (HxH, HxW from hatchery females and wild males, and WxW) in hatcheries, and tested for differences in survival, growth, early maturation, downstream migration, and adult returns. Rearing treatments were mixed (crosses reared together) and separate (crosses reared separately from each other) at the hatchery of origin for the hatchery population where smolts are produced in one year, and at a nearby hatchery employing lower rations, lower winter temperatures, and two years of rearing to more closely mimic the natural life history (natural smolt age = 2-4 years). The hatchery population had been artificially propagated for six generations at the onset of our study. We found little or no difference in survival in the hatchery but substantially higher rates of growth and subsequent downstream migration for HxH than for WxW fish. Faster growth for HxH fish resulted in greater size at release which contributed to their higher migration rate, but other as yet uncharacterized traits also affected migration since the migration difference between crosses was apparent even within size classes. Growth of WxW fish was slower in the mixed than in the separate treatment indicating that WxW fish were competitively inferior to HxH fish in the hatchery environment. Incidence of precocious males was higher for WxW than for HxH fish in the separate but not in the mixed treatment. Incidence of HxH precocious males was similar between treatments. Apparently, the presence of HxH fish suppressed high incidence of early maturation by WxW males. A direct effect beyond

  5. Development and morphology of point bars in tidal rivers, observations from Sapelo and the Altamaha River, GA

    NASA Astrophysics Data System (ADS)

    Hughes, Z. J.; Georgiou, I. Y.; Howes, N. C.; Weathers, D.; Kulp, M.; FitzGerald, D. M.

    2012-12-01

    Many tidal creeks and rivers exhibit bars associated with meander bends. However, hydrodynamic and morphodynamic studies of these point-bars are scarce, compared with the extensive studies of fluvial-point bars. The few studies that have been undertaken suggest significant differences between tidal bars and their fluvial counterparts, including low rates of channel migration, a unique planform morphology resulting from the bi-directional tidal flows and tidal asymmetry, and variation in stage-discharge behavior. We examine point-bars in two closely situated estuaries on the Georgia coast: the Altamaha and Sapelo. Both sites are meso-tidal; however, the Altamaha has significant fluvial input, whereas the Sapelo creeks have minimal fluvial input. Both sites exhibit mixed sand-mud point bars of various sizes. However, sites dominated by fluvial processes are coarser-grained and contain a higher percentage of sand. Velocity measurements from vessel-mounted and moored acoustic Doppler current profilers record the separation of flood and ebb flows to either side of the tidal bars, which results in a residual circulation over their surface. Large bedforms with opposing migration directions are observed on either side of the bar, suggesting that each side of the channel experiences a separate sediment transport regime. Shallow seismic data at two resolutions (Boomer and Chirp) indicate that the internal architecture of the tidal bars consists of lateral accretion surfaces with multi-directional strike orientations and dips, suggesting a more complex pattern of growth and development. We compare and contrast the hydrodynamics and the resulting morphologies of the bars and identify differences between fluvially-influenced and purely tidal environments. This data set also allows us to examine the hypothesis that these forms are scale invariant by examining a wide range of bars in both large and small channels.

  6. Numerical Model Predictions for Autogenic Fluvial Terrace Formation and Comparison to Natural River Valleys

    NASA Astrophysics Data System (ADS)

    Limaye, A. B. S.; Lamb, M. P.

    2015-12-01

    Terraces cut into bedrock (strath) and sediment (fill-cut) offer key constraints on river evolution over millennial timescales, and are often interpreted to form during phases of increased river vertical incision driven by changes in climate or tectonics. Yet all actively meandering channels evolve their shapes through spatial and temporal changes in lateral erosion rates. Therefore, the sparsest requirement for a meandering river to generate terraces is that the intrinsically unsteady lateral erosion rate be coupled with relief generation by vertical incision, which need not be unsteady. In principle, this basic mechanism for terrace formation by meandering rivers should be possible in all fluvial environments, including for valleys with strath or fill-cut terraces, and may overprint signals from external drivers. We have used a numerical model of a vertically incising, meandering river to identify the age and geometric properties of autogenic terraces. Simulations indicate that autogenic terraces form with a recurrence timescale, set by the rate of relief generation, which may overlap with timescales for climate change. The autogenic terraces also have predictable geometries that can include slope proportional to the ratio of vertical incision rate to lateral erosion rate, pairing, and continuous along-valley extent. We compare these simulation results to data for terrace age and geometry from several well studied natural river valleys that span a wide range in terrace sizes and geometries, rock types, tectonic settings, incision rates, and hypothesized formation mechanisms. In cases, terrace age and geometric properties are consistent with formation by meandering with constant vertical incision rates. These similarities suggest that efforts to distinguish terraces that record signals from climatic and tectonic drivers are best focused on environments where terrace ages and geometries are far different than would be predicted by a constant vertical incision model.

  7. Polychlorinated Biphenyls in suspended-sediment samples from outfalls to Meandering Road Creek at Air Force Plant 4, Fort Worth, Texas, 2003-08

    USGS Publications Warehouse

    Braun, Christopher L.; Wilson, Jennifer T.

    2010-01-01

    Meandering Road Creek is an intermittent stream and tributary to Lake Worth, a reservoir on the West Fork Trinity River on the western edge of Fort Worth, Texas. U.S. Air Force Plant 4 (AFP4) is on the eastern shore of Woods Inlet, an arm of Lake Worth. Meandering Road Creek gains inflow from several stormwater outfalls as it flows across AFP4. Several studies have characterized polychlorinated biphenyls (PCBs) in the water and sediments of Lake Worth and Meandering Road Creek; sources of PCBs are believed to originate primarily from AFP4. Two previous U.S. Geological Survey (USGS) reports documented elevated PCB concentrations in surficial sediment samples from Woods Inlet relative to concentrations in surficial sediment samples from other parts of Lake Worth. The second of these two previous reports also identified some of the sources of PCBs to Lake Worth. These reports were followed by a third USGS report that documented the extent of PCB contamination in Meandering Road Creek and Woods Inlet and identified runoff from outfalls 4 and 5 at AFP4 as prominent sources of these PCBs. This report describes the results of a fourth study by the USGS, in cooperation with the Lockheed Martin Corporation, to investigate PCBs in suspended-sediment samples in storm runoff from outfalls 4 and 5 at AFP4 following the implementation of engineering controls designed to potentially alleviate PCB contamination in the drainage areas of these outfalls. Suspended-sediment samples collected from outfalls 4 and 5 during storms on March 2 and November 10, 2008, were analyzed for selected PCBs. Sums of concentrations of 18 reported PCB congeners (Sigma PCBc) in suspended-sediment samples collected before and after implementation of engineering controls are compared. At both outfalls, the Sigma PCBc before engineering controls was higher than the Sigma PCBc after engineering controls. The Sigma PCBc in suspended-sediment samples collected at AFP4 before and after implementation of

  8. Adult Pacific Lamprey Migration Behavior and Escapement in the Bonneville Reservoir and Lower Columbia River Monitored Using the Juvenile Salmonid Acoustic Telemetry System (JSATS), 2011

    DTIC Science & Technology

    2012-01-01

    Technical Report 2012-4 IDAHO COOPERATIVE FISH AND WILDLIFE RESEARCH UNIT ADULT PACIFIC LAMPREY MIGRATION BEHAVIOR AND ESCAPEMENT IN THE...C.C. Caudill, T.S. Clabough, D.C. Joosten, E.L. Johnson, M.L. Keefer, and G.P. Naughton Department of Fish and Wildlife Sciences Idaho...Cooperative Fish and Wildlife Research Unit University of Idaho, Moscow, ID 83844-1136 for U.S. Army Corps of Engineers Portland District

  9. Quantifying the Geomorphic Dynamics of the Extensively Impacted Lower Yuba River

    NASA Astrophysics Data System (ADS)

    Wyrick, J. R.; Pasternack, G. B.; Carley, J. K.; Barker, R.; Massa, D.; Bratovich, P.; Reedy, G.; Johnson, T.

    2010-12-01

    potential for significant morphological adjustment since ~1950 on the basis of visual indicators and aerial photos. To conduct a quantitative analysis, two raster DEMs of the entire LYR from a decade apart were differenced with a method accounting for uncertainty. Then the resulting spatial pattern of high-confidence erosion and deposition were analyzed by stratifying the river according to different “masks”, such as morphological unit types, reaches, and process domains. Overall, the most conservative account indicated that there was 3,887,384 m3 of cut and 3,758,810 m3 of fill, yielding a net export of 128,574 m3. Alignment of the DEM difference results with historical aerial photos and 2D model simulations revealed the relative roles of different processes in the river, such as meander migration, kickpoint migration, and non-meander bank erosion. After 68 years of post-dam blockage of hydraulic mining influx, the LYR is still highly dynamic and adjusting. The results of this study are being used to guide diverse river management and rehabilitation actions.

  10. Bathymetric surveys of the Kootenai River near Bonners Ferry, Idaho, water year 2011

    USGS Publications Warehouse

    Fosness, Ryan L.

    2013-01-01

    In 2009, the Kootenai Tribe of Idaho released and implemented the Kootenai River Habitat Restoration Master Plan. This plan aimed to restore, enhance, and maintain the Kootenai River habitat and landscape to support and sustain habitat conditions for aquatic species and animal populations. In support of these restoration efforts, the U.S. Geological Survey, in cooperation with the Kootenai Tribe of Idaho, conducted high-resolution multibeam echosounder bathymetric surveys in May, June, and July 2011, as a baseline bathymetric monitoring survey on the Kootenai River near Bonners Ferry, Idaho. Three channel patterns or reaches exist in the study area—braided, meander, and a transitional zone connecting the braided and meander reaches. Bathymetric data were collected at three study areas in 2011 to provide: (1) surveys in unmapped portions of the meander reach; (2) monitoring of the presence and extent of sand along planned lines within a section of the meander reach; and (3) monitoring aggradation and degradation of the channel bed at specific cross sections within the braided reach and transitional zone. The bathymetric data will be used to update and verify flow models, calibrate and verify sediment transport modeling efforts, and aid in the biological assessment in support of the Kootenai River Habitat Restoration Master Plan. The data and planned lines for each study reach were produced in ASCII XYZ format supported by most geospatial software.

  11. Investigating fluvial features with electrical resistivity imaging and ground-penetrating radar: The Guadalquivir River terrace (Jaen, Southern Spain)

    NASA Astrophysics Data System (ADS)

    Rey, J.; Martínez, J.; Hidalgo, M. C.

    2013-09-01

    A geophysical survey has been conducted on the lowest terrace levels and the present day floodplain of the current course of the Guadalquivir River, passing through the province of Jaen (Spain), using two techniques: electrical resistivity imaging (ERI) and ground-penetrating radar (GPR). Three areas have been selected. In one of these sectors (Los Barrios) there is an old quarry where there are excellent outcrops that allow for the calibration of the survey techniques. Facies associations on these outcrops are typical of meandering rivers with sequences of channel fills, lateral accretion of point-bars and floodplain facies. The usefulness of the two methods is analysed and compared as a support for stratigraphic and sedimentological studies. The geometry and lithofacies of subsurface deposits were characterised using ERI and compared with field observations. A total of 5 electrical resistivity imaging profiles were obtained. The changes in electric resistivity highlight granulometric differences in terrace sediments. This technique can thus be used to identify the morphology of these bodies, the lithofacies (silt, sand or gravel) and buried channel pattern. In addition, 16 GPR profiles using 100 and 250 MHz antennas were acquired, indicating terrace morphology and the filling of the sedimentary bodies in a more detailed manner than in ERI. The study thus allows for inferring the existence of channel migration, the lateral accretion of point bars and the presence of vertical accretion deposits attributable to the floodplains.

  12. Migration delays caused by anthropogenic barriers: modeling dams, temperature, and success on migrating salmon smolts

    USGS Publications Warehouse

    Marschall, Elizabeth A.; Mather, Martha E.; Parrish, Donna; Allison, Gary W.; McMenemy, James R.

    2011-01-01

    Disruption to migration is a growing problem for conservation and restoration of animal populations. Anthropogenic barriers along migration paths can delay or prolong migrations, which may result in a mismatch with migration-timing adaptations. To understand the interaction of dams (as barriers along a migration path), seasonally changing environmental conditions, timing of Atlantic salmon (Salmo salar) downstream migration, and ultimate migration success, we used 10 years of river temperature and discharge data as a template upon which we simulated downstream movement of salmon. Atlantic salmon is a cool-water species whose downstream migrating smolts must complete migration before river temperatures become too warm. We found that dams had a local effect on survival as well as a survival effect that was spatially and temporally removed from the encounter with the dam. While smolts are delayed by dams, temperatures downstream can reach lethal or near-lethal temperatures; as a result, the match between completion of migration and the window of appropriate migration conditions can be disrupted. The strength of this spatially and temporally removed effect is at least comparable to the local effects of dams in determining smolt migration success in the presence of dams. We also considered smolts from different tributaries, varying in distance from the river mouth, to assess the potential importance of locally adapted migration timing on the effect of barriers. Migration-initiation temperature affected modeled smolt survival differentially across tributaries, with the success of smolts from upstream tributaries being much more variable across years than that of smolts with a shorter distance to travel. As a whole, these results point to the importance of broadening our spatial and temporal view when managing migrating populations. We must consider not only how many individuals never make it across migration barriers, but also the spatially and temporally removed

  13. Migration delays caused by anthropogenic barriers: Modeling dams, temperature, and success of migrating salmon smolts

    USGS Publications Warehouse

    Marschall, E.A.; Mather, M. E.; Parrish, D.L.; Allison, G.W.; McMenemy, J.R.

    2011-01-01

    Disruption to migration is a growing problem for conservation and restoration of animal populations. Anthropogenic barriers along migration paths can delay or prolong migrations, which may result in a mismatch with migration-timing adaptations. To understand the interaction of dams (as barriers along a migration path), seasonally changing environmental conditions, timing of Atlantic salmon (Salmo salar) downstream migration, and ultimate migration success, we used 10 years of river temperature and discharge data as a template upon which we simulated downstream movement of salmon. Atlantic salmon is a cool-water species whose downstream migrating smolts must complete migration before river temperatures become too warm. We found that dams had a local effect on survival as well as a survival effect that was spatially and temporally removed from the encounter with the dam. While smolts are delayed by dams, temperatures downstream can reach lethal or near-lethal temperatures;as a result, the match between completion of migration and the window of appropriate migration conditions can be disrupted. The strength of this spatially and temporally removed effect is at least comparable to the local effects of dams in determining smolt migration success in the presence of dams. We also considered smolts from different tributaries, varying in distance from the river mouth, to assess the potential importance of locally adapted migration timing on the effect of barriers. Migration-initiation temperature affected modeled smolt survival differentially across tributaries, with the success of smolts from upstream tributaries being much more variable across years than that of smolts with a shorter distance to travel. As a whole, these results point to the importance of broadening our spatial and temporal view when managing migrating populations. We must consider not only how many individuals never make it across migration barriers, but also the spatially and temporally removed

  14. Sun River (24CA74): A Stratified Pelican Lake and Oxbow Occupation Site near Great Falls, Montana.

    DTIC Science & Technology

    1983-08-31

    River meanders eastward through rolling, short grass prairie foothills, to its confluence with the Missouri River. North of the site, the flood plain...is bordered by rolling hills and benchlands of typical short grass prairie vegetation (Fig. 1-3). Deciduous trees and bushes cluster along tributary...TABLE 1-1 PLANT SPECIES OBSEWED AT THE SUN RIVER SITE GRASSES Green needlegrass--Stipa viridula Western and thickspike wheatgrass--Agropyron smithii and

  15. Impacts of climate and land-use changes on the migration of non-point source nitrogen and phosphorus during rainfall-runoff in the Jialing River Watershed, China

    NASA Astrophysics Data System (ADS)

    Wu, Lei; Long, Tian-yu; Liu, Xia; Guo, Jin-song

    2012-12-01

    SummaryThe loss of nitrogen and phosphorus via non-point source (NPS) pollution in the Jialing River Watershed has become the main pollution sources of river waters in the Three Gorges reservoir area in the past decades, while climatic conditions and human activities directly affect changes of rainfall-runoff and land use types which are closely related to NPS pollution. This study is to assess the impact of climate change on hydrological behavior considering future land-use types and rural residential area and their propagation to NPS pollution loads. An integrated pollution load model composed of regional climate, the Semi-distributed Land Use based Runoff Processes (SLURPs) hydrological model and the improved export coefficient approach within a single framework was explored and developed to assess impacts of climate and land-use changes on NPS pollution load. Climate data for the Special Report on Emissions Scenarios (SRESs) future scenario B2 from Met Office Hadley center were generated and used as the input data for the runoff and NPS load evaluation of the Jialing River Watershed and the Markov process was used to forecast changes of land use types, respectively. Simulations of present and future regional NPS pollution from land use, livestock and poultry breeding, and agricultural population over the Jialing River Watershed were performed to investigate the potential impacts of global climate change on river water quality using the established model. Results demonstrate that: (1) Annual pollution load would obviously change due to variations of runoff and livestock and poultry breeding, the largest growth months in one year for total nitrogen (TN) and total phosphorus (TP) load are both in June, which is in accordance with changes of rainfall amount. (2) The impacts of global climate change on pollution load are relatively greater when compared to the impacts of future livestock and poultry breeding increase or agricultural population reduction; the effects

  16. When Smoothening Makes It Rough: Unhindered Step-Edge Diffusion and the Meandering Instability on Metal Surfaces

    SciTech Connect

    Nita, F.; Pimpinelli, A.

    2005-09-02

    The precise microscopic origin of step meandering is not known in many real situations. A detailed study of this instability has been made for copper, and none of the microscopic mechanisms proposed until now is able to describe all of the observed characteristic features of the instability, in particular, its dependence on the crystallographic orientations of steps. We propose a novel scenario, and using kinetic Monte Carlo simulations we show that essentially all features of step meandering of copper can be explained, if atoms diffuse along step edges and freely turn around the kinks they encounter along the ledge. Then, in a rather counterintuitive way, step meandering appears due to the very mechanism -step-edge diffusion - that may be expected to oppose it.

  17. Sedimentological characterization of braided and meandering fluvial reservoirs: Prediction of size and heterogeneity

    SciTech Connect

    Davies, D.K. ); Vargas, J. )

    1993-02-01

    Fluvial reservoirs host significant volumes of hydrocarbons. They comprise a significant reserve base in areas and formations as diverse as the San Jorge Basin, Argentina, the Lagunillas Formation, Venezuela, and Cano Limon Field, Colombia. Effective development and reservoir management required detailed sedimentological characterization because fluvial reservoirs, irrespective of age and geographic location, are characterized by considerable variability in geometry and internal heterogeneity. This paper presents models of braided and meandering reservoirs in selected Tertiary and Cretaceous fields of South and North America, based on sedimentological characterization using conventional cores and wireline logs. Fieldwide (macro-scale) and inter-well (meso-scale) heterogeneity is determined through detailed evaluation of facies distribution, particularly the distribution and maturity of paleosol horizons (e.g. calcretes). Within a given reservoir, micro-scale variations in porosity, permeability and saturation are fundamentally related to depositional environment. Effective permeability to hydrocarbons varies with environment and bedding style. The size of meandering and braided channel reservoirs is predicted using empirical geological equations. Predicted dimensions are compared with the independent results of reservoir simulation analysis for the same sand bodies. Engineering and sedimentological predictions of reservoir size and heterogeneity are similar, particularly in reservoirs where median permeability to hydrocarbons is > 1 md. The size and heterogeneity of productive channel reservoirs can be predicted at an early stage in field development is channel style and channel depth are known. Determination of these two fundamental parameters required sedimentological characterization at the macro-, meso-, and micro-scale using wireline logs and cores.

  18. Estimating stream filtration from a meandering stream under the Robin condition

    NASA Astrophysics Data System (ADS)

    Huang, Ching-Sheng; Yeh, Hund-Der

    2015-06-01

    This study applies image well theory to estimate the stream depletion rate (SDR) due to pumping near a meandering stream with a clogged streambed treated as the Robin condition. The stream is considered as an irregular boundary represented by discrete nodes. Image wells are arranged along the stream and near those nodes. On the basis of the Theis (1935) solution and the principle of superposition, the solution for the aquifer drawdown subject to the stream can then be expressed as the sum of the Theis solution and a simple series representing the effect of those image wells. The discharge rates of the image wells are determined by solving a system of equations obtained by substituting the drawdown solution into the Robin condition. Quantitative criteria for assessing the applicability of the image well theory are provided. On the basis of the drawdown solution and Darcy's law, the analytical solution for SDR can then be obtained. A finite element solution is also developed to verify the SDR solution. Temporal SDR distributions predicted by both the analytical solution and finite element solution agree well over the entire period except at late time when the stream filtration rate approaches the pumping rate (i.e., SDR ≅ 1). It is found that a meandering stream has a significant effect on SDR compared with a rectilinear one and the effect should be taken into account in estimating SDR.

  19. Dynamics of meandering spiral waves under the modulation of a dichotomous noise

    NASA Astrophysics Data System (ADS)

    Yuan, Guoyong; Ma, Litao; Xu, Lijun; Wang, Guangrui; Yang, Shiping

    2014-04-01

    In this paper, we study the effect of a dichotomous noise on meandering spiral dynamics, and exhibit how the cycloid motion of the meandering spiral tip is destroyed by the noise. Switching on the noise does not alter the primary frequency f1 and the secondary frequency f2 in the tip motion, which is different from the case for a periodic dichotomous modulation, where f2 is changed according to two specific rules. However, the dichotomous noise leads to a decrease of the amplitudes at f1 and f2, and the rate of decrease of the amplitude at f2 is larger than that at f2 in the process of increasing the noise intensity or the correlation. The areas with small v-values (SV) are defined, and the distribution and size of the SV areas are analyzed, in order to explain and describe these results. It is also proved that spiral waves can be eliminated by the dichotomous noise with a large amplitude or correlation.

  20. Bandwidth enhancement of a dual band planar monopole antenna using meandered microstrip feeding.

    PubMed

    Ahsan, M R; Islam, M T; Habib Ullah, M; Misran, N

    2014-01-01

    A meandered-microstrip fed circular shaped monopole antenna loaded with vertical slots on a high dielectric material substrate (ε r = 15) is proposed in this paper. The performance criteria of the proposed antenna have been experimentally verified by fabricating a printed prototype. The experimental results show that the proposed antenna has achieved wider bandwidth with satisfactory gain by introducing meandered-microstrip feeding in assistant of partial ground plane. It is observed that, the -10 dB impedance bandwidth of the proposed antenna at lower band is 44.4% (600 MHz-1 GHz) and at upper band is 28% (2.25 GHz-2.95 GHz). The measured maximum gains of -1.18 dBi and 4.87 dBi with maximum radiation efficiencies have been observed at lower band and upper band, respectively. The antenna configuration and parametric study have been carried out with the help of commercially available computer-aided EM simulator, and a good accordance is perceived in between the simulated and measured results. The analysis of performance criteria and almost consistent radiation pattern make the proposed antenna a suitable candidate for UHF RFID, WiMAX, and WLAN applications.