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Sample records for bed-load sediment transport

  1. Exploring the role of flood transience in coarse bed load sediment transport

    NASA Astrophysics Data System (ADS)

    Phillips, C. B.; Singer, M. B.; Hill, K. M.; Paola, C.

    2015-12-01

    The rate of bed load transport under steady flow is known to vary both spatially and temporally due to various hydrologic and granular phenomena. Grain size distributions and riverbed properties (packing, imbrication, etc.) are known to affect flux for a particular value of applied flow stress, while hydrology is mainly assumed to control the magnitude of the applied bed stress above the threshold for bed material entrainment. The prediction of bed load sediment transport in field settings is further complicated by the inherent transience in flood hydrology, but little is known about how such flood transience influences bed load flux over a range of applied bed stress. Here we investigate the role of flood transience for gravel bed load transport through controlled laboratory experiments in a 28 m long 0.5 meter wide flume. We explore transient flow as the combination of unsteady and intermittent flow, where unsteady flow varies in magnitude over a given duration, and intermittent flow is characterized by turning the flow on and off. We systematically vary these details of flood hydrographs from one experiment to the next, and monitor the bed load as it varies with water discharge in real time by measuring sediment flux and tracking particles. We find that even with a narrow unimodal grain size distribution and constant sediment supply we observe hysteresis in bed load flux, different thresholds for entrainment and distrainment for the rising and falling limbs of a flood, and a threshold of entrainment that can vary one flood hydrograph to the next. Despite these complex phenomena we find that the total bed load transported for each flood plots along a linear trend with the integrated excess stress, consistent with prior field results. These results suggest that while the effects of transient flow and the shape of the hydrograph are measurable, they are second-order compared to the integrated excess stress.

  2. Bed load transport in gravel-bed rivers

    Treesearch

    Jeffrey J. Barry

    2007-01-01

    Bed load transport is a fundamental physical process in alluvial rivers, building and maintaining a channel geometry that reflects both the quantity and timing of water and the volume and caliber of sediment delivered from the watershed. A variety of formulae have been developed to predict bed load transport in gravel-bed rivers, but testing of the equations in natural...

  3. Field assessment of alternative bed-load transport estimators

    USGS Publications Warehouse

    Gaeuman, G.; Jacobson, R.B.

    2007-01-01

    Measurement of near-bed sediment velocities with acoustic Doppler current profilers (ADCPs) is an emerging approach for quantifying bed-load sediment fluxes in rivers. Previous investigations of the technique have relied on conventional physical bed-load sampling to provide reference transport information with which to validate the ADCP measurements. However, physical samples are subject to substantial errors, especially under field conditions in which surrogate methods are most needed. Comparisons between ADCP bed velocity measurements with bed-load transport rates estimated from bed-form migration rates in the lower Missouri River show a strong correlation between the two surrogate measures over a wide range of mild to moderately intense sediment transporting conditions. The correlation between the ADCP measurements and physical bed-load samples is comparatively poor, suggesting that physical bed-load sampling is ineffective for ground-truthing alternative techniques in large sand-bed rivers. Bed velocities measured in this study became more variable with increasing bed-form wavelength at higher shear stresses. Under these conditions, bed-form dimensions greatly exceed the region of the bed ensonified by the ADCP, and the magnitude of the acoustic measurements depends on instrument location with respect to bed-form crests and troughs. Alternative algorithms for estimating bed-load transport from paired longitudinal profiles of bed topography were evaluated. An algorithm based on the routing of local erosion and deposition volumes that eliminates the need to identify individual bed forms was found to give results similar to those of more conventional dune-tracking methods. This method is particularly useful in cases where complex bed-form morphology makes delineation of individual bed forms difficult. ?? 2007 ASCE.

  4. Sediment and Fecal Indicator Bacteria Loading in a Mixed Land Use Watershed: Contributions from Suspended and Bed Load Transport

    EPA Science Inventory

    Water quality studies that quantify sediment and fecal bacteria loading commonly focus on suspended contaminants transported during high flows. Fecal contaminants in bed sediments are typically ignored and need to be considered because of their potential to increase pathogen load...

  5. Bed load transport by submerged jets

    PubMed Central

    Francis, J. R. D.; McCreath, P. S.

    1979-01-01

    Some similarities are presented between the bed load transport of noncohesive grains in long rivers and at a local, jet-induced scour. Experiments are described in which a submerged two-dimensional slot nozzle, inclined downward, eroded a deep sand bed. The rate of erosion at the very beginning of a scour was evaluated and compared with river data by use of the idea of “stream-power.” Empirical relationships for the two cases are similar, although the geometry of the boundaries is quite different. PMID:16592696

  6. Scaling relationships between bed load volumes, transport distances, and stream power in steep mountain channels

    NASA Astrophysics Data System (ADS)

    Schneider, Johannes M.; Turowski, Jens M.; Rickenmann, Dieter; Hegglin, Ramon; Arrigo, Sabrina; Mao, Luca; Kirchner, James W.

    2014-03-01

    Bed load transport during storm events is both an agent of geomorphic change and a significant natural hazard in mountain regions. Thus, predicting bed load transport is a central challenge in fluvial geomorphology and natural hazard risk assessment. Bed load transport during storm events depends on the width and depth of bed scour, as well as the transport distances of individual sediment grains. We traced individual gravels in two steep mountain streams, the Erlenbach (Switzerland) and Rio Cordon (Italy), using magnetic and radio frequency identification tags, and measured their bed load transport rates using calibrated geophone bed load sensors in the Erlenbach and a bed load trap in the Rio Cordon. Tracer transport distances and bed load volumes exhibited approximate power law scaling with both the peak stream power and the cumulative stream energy of individual hydrologic events. Bed load volumes scaled much more steeply with peak stream power and cumulative stream energy than tracer transport distances did, and bed load volumes scaled as roughly the third power of transport distances. These observations imply that large bed load transport events become large primarily by scouring the bed deeper and wider, and only secondarily by transporting the mobilized sediment farther. Using the sediment continuity equation, we can estimate the mean effective thickness of the actively transported layer, averaged over the entire channel width and the duration of individual flow events. This active layer thickness also followed approximate power law scaling with peak stream power and cumulative stream energy and ranged up to 0.57 m in the Erlenbach, broadly consistent with independent measurements.

  7. Performance of bed load transport equations in mountain gravel-bed rivers: A re-analysis

    Treesearch

    Jeffrey J. Barry; John M. Buffington; John G. King; Peter Goodwin

    2006-01-01

    Our recent examination of bed load transport data from mountain gravel-bed rivers in the western United States shows that the data can be fit by a simple power function of discharge, with the coefficient being a function of drainage area (a surrogate for basin sediment supply) and the exponent being a function of supply-related channel armoring (transport capacity in...

  8. A general power equation for predicting bed load transport rates in gravel bed rivers

    Treesearch

    Jeffrey J. Barry; John M. Buffington; John G. King

    2004-01-01

    A variety of formulae has been developed to predict bed load transport in gravel bed rivers, ranging from simple regressions to complex multiparameter formulations. The ability to test these formulae across numerous field sites has, until recently, been hampered by a paucity of bed load transport data for gravel bed rivers. We use 2104 bed load transport observations...

  9. Evaluation of a numerical model's ability to predict bed load transport observed in braided river experiments

    NASA Astrophysics Data System (ADS)

    Javernick, Luke; Redolfi, Marco; Bertoldi, Walter

    2018-05-01

    New data collection techniques offer numerical modelers the ability to gather and utilize high quality data sets with high spatial and temporal resolution. Such data sets are currently needed for calibration, verification, and to fuel future model development, particularly morphological simulations. This study explores the use of high quality spatial and temporal data sets of observed bed load transport in braided river flume experiments to evaluate the ability of a two-dimensional model, Delft3D, to predict bed load transport. This study uses a fixed bed model configuration and examines the model's shear stress calculations, which are the foundation to predict the sediment fluxes necessary for morphological simulations. The evaluation is conducted for three flow rates, and model setup used highly accurate Structure-from-Motion (SfM) topography and discharge boundary conditions. The model was hydraulically calibrated using bed roughness, and performance was evaluated based on depth and inundation agreement. Model bed load performance was evaluated in terms of critical shear stress exceedance area compared to maps of observed bed mobility in a flume. Following the standard hydraulic calibration, bed load performance was tested for sensitivity to horizontal eddy viscosity parameterization and bed morphology updating. Simulations produced depth errors equal to the SfM inherent errors, inundation agreement of 77-85%, and critical shear stress exceedance in agreement with 49-68% of the observed active area. This study provides insight into the ability of physically based, two-dimensional simulations to accurately predict bed load as well as the effects of horizontal eddy viscosity and bed updating. Further, this study highlights how using high spatial and temporal data to capture the physical processes at work during flume experiments can help to improve morphological modeling.

  10. Statistical description of flume experiments on mixed-size bed-load transport and bed armoring processes

    NASA Astrophysics Data System (ADS)

    Chen, D.; Zhang, Y.

    2008-12-01

    The objective of this paper is to describe the statistical properties of experiments on non-uniform bed-load transport as well as the mechanism of bed armoring processes. Despite substantial effort made over the last two decades, the ability to compute the bed-load flux in a turbulent system remains poor. The major obstacles include the poor understanding of the formation of armor lays on bed surfaces. Such a layer is much flow-resistible than the underlying material and therefore significantly inhibits sediment transport from the reach. To study the problem, we conducted a flume study for mixed sand/gravel sediments. We observed that aggregated sediment blocks were the most common characters in armor layers - the largest sizes resist hydraulic forces, while the smaller sizes add interlocking support and prevent loss of fine material through gaps between the larger particles. Fractional transport rates with the existing of armor layers were measured with time by sediment trapping method at the end of flume. To address the intermittent and time-varying behavior of bed-load transport during bed armoring processes, we investigated the probability distribution of the fractional bed-load transport rates, and the underlying dynamic model derived from the continuous time random walk framework. Results indicate that it is critical to consider the impact of armor layers when a flow is sufficient to move some of the finer particles and yet insufficient to move all the larger particles on a channel bed.

  11. Sediment and Hydraulic Measurements with Computed Bed Load on the Missouri River, Sioux City to Hermann, 2014

    DTIC Science & Technology

    2017-05-01

    large sand bed river, with seven sites representing increasingly larger flows along the river length. The data set will be very useful for additional...quantity, quality , and types of data that can be obtained for the study of natural phenomenon. The study of riverine sedimentation is no exception...detail than in previous years. Additionally, new methodologies have been developed that allow the computation of bed-load transport in large sand bed

  12. Peering inside the granular bed: illuminating feedbacks between bed-load transport and bed-structure evolution

    NASA Astrophysics Data System (ADS)

    Houssais, M.; Jerolmack, D. J.; Martin, R. L.

    2013-12-01

    The threshold of motion is perhaps the most important quantity to determine for understanding rates of bed load transport, however it is a moving target. Decades of research show that it changes in space and in time within a river, and is highly variable among different systems; however, these differences are not mechanistically understood. Recent researchers have proposed that the critical Shields stress is strongly dependent on the local configuration of the sediment bed [Frey and Church, 2011]. Critical Shields stress has been observed to change following sediment-transporting flood events in natural rivers [e.g., Turowski et al., 2011], while small-scale laboratory experiments have produced declining bed load transport rates associated with slow bed compaction [Charru et al., 2004]. However, no direct measurements have been made of the evolving bed structure under bed load transport, so the connection between granular controls and the threshold of motion remains uncertain. A perspective we adopt is that granular effects determine the critical Shields stress, while the fluid supplies a distribution of driving stresses. In order to isolate the granular effect, we undertake laminar bed load transport experiments using plastic beads sheared by a viscous oil in a small, annular flume. The fluid and beads are refractive index matched, and the fluid impregnated with a fluorescing powder. When illuminated with a planar laser sheet, we are able to image slices of the granular bed while also tracking the overlying sediment transport. We present the first results showing how bed load transport influences granular packing, and how changes in packing influence the threshold of motion to feed back on bed load transport rates. This effect may account for much of the variability observed in the threshold of motion in natural streams, and by extension offers a plausible explanation for hysteresis in bed load transport rates observed during floods. Charru, F., H. Mouilleron, and

  13. Comparison of genetic algorithm and imperialist competitive algorithms in predicting bed load transport in clean pipe.

    PubMed

    Ebtehaj, Isa; Bonakdari, Hossein

    2014-01-01

    The existence of sediments in wastewater greatly affects the performance of the sewer and wastewater transmission systems. Increased sedimentation in wastewater collection systems causes problems such as reduced transmission capacity and early combined sewer overflow. The article reviews the performance of the genetic algorithm (GA) and imperialist competitive algorithm (ICA) in minimizing the target function (mean square error of observed and predicted Froude number). To study the impact of bed load transport parameters, using four non-dimensional groups, six different models have been presented. Moreover, the roulette wheel selection method is used to select the parents. The ICA with root mean square error (RMSE) = 0.007, mean absolute percentage error (MAPE) = 3.5% show better results than GA (RMSE = 0.007, MAPE = 5.6%) for the selected model. All six models return better results than the GA. Also, the results of these two algorithms were compared with multi-layer perceptron and existing equations.

  14. Marginal bed load transport in a gravel bed stream, Sagehen Creek, California

    USGS Publications Warehouse

    Andrews, E.D.

    1994-01-01

    Marginal bed load transport describes the condition when relatively few bed particles are moving at any time. Bed particles resting in the shallowest bed pockets will move when the dimensionless shear stress т* exceeds a value of about 0.020. As т* increases, the number of bed particles moving increases. Significant motion of bed particles, i.e., when a substantial fraction of the bed particles are moving, occurs when т* exceeds a value of about 0.060. Thus marginal bed load transport occurs over the domain 0.020 < т* < 0.060. Marginal bed load transport rates and associated hydraulic characteristics of Sagehen Creek, a small mountain gravel bed stream, were measured on 55 days at discharges ranging from slightly less than one half of the bank-full discharge to more than 4 times the bank-full discharge. Dimensionless shear stress varied from 0.032 to 0.042, and bed particles as large as the 80th percentile of the bed surface were transported. The relation between reference dimensionless shear stress and relative particle protrusion for Sagehen Creek was determined by varying т*ri to obtain the best fit of the Parker bed load function to the measured transport rates. During the period of record (water years 1954–1991), the mean annual quantity of bed load transported past the Sagehen Creek gage was 24.7 tons. Forty-seven percent of all bed load transported during the 38 years of record occurred in just 6 years. During 10 of the 38 years of record, essentially no bed load was transported. The median diameter of bed load was 26 mm, compared to 58 mm in the surface bed material.

  15. Bed load transport over a broad range of timescales: Determination of three regimes of fluctuations

    NASA Astrophysics Data System (ADS)

    Ma, Hongbo; Heyman, Joris; Fu, Xudong; Mettra, Francois; Ancey, Christophe; Parker, Gary

    2014-12-01

    This paper describes the relationship between the statistics of bed load transport flux and the timescale over which it is sampled. A stochastic formulation is developed for the probability distribution function of bed load transport flux, based on the Ancey et al. (2008) theory. An analytical solution for the variance of bed load transport flux over differing sampling timescales is presented. The solution demonstrates that the timescale dependence of the variance of bed load transport flux reduces to a three-regime relation demarcated by an intermittency timescale (tI) and a memory timescale (tc). As the sampling timescale increases, this variance passes through an intermittent stage (≪tI), an invariant stage (tI < t < tc), and a memoryless stage (≫ tc). We propose a dimensionless number (Ra) to represent the relative strength of fluctuation, which provides a common ground for comparison of fluctuation strength among different experiments, as well as different sampling timescales for each experiment. Our analysis indicates that correlated motion and the discrete nature of bed load particles are responsible for this three-regime behavior. We use the data from three experiments with high temporal resolution of bed load transport flux to validate the proposed three-regime behavior. The theoretical solution for the variance agrees well with all three sets of experimental data. Our findings contribute to the understanding of the observed fluctuations of bed load transport flux over monosize/multiple-size grain beds, to the characterization of an inherent connection between short-term measurements and long-term statistics, and to the design of appropriate sampling strategies for bed load transport flux.

  16. Performance of bed-load transport equations relative to geomorphic significance: Predicting effective discharge and its transport rate

    Treesearch

    Jeffrey J. Barry; John M. Buffington; Peter Goodwin; John .G. King; William W. Emmett

    2008-01-01

    Previous studies assessing the accuracy of bed-load transport equations have considered equation performance statistically based on paired observations of measured and predicted bed-load transport rates. However, transport measurements were typically taken during low flows, biasing the assessment of equation performance toward low discharges, and because equation...

  17. Evaluation of bed load transport subject to high shear stress fluctuations

    NASA Astrophysics Data System (ADS)

    Cheng, Nian-Sheng; Tang, Hongwu; Zhu, Lijun

    2004-05-01

    Many formulas available in the literature for computing sediment transport rates are often expressed in terms of time mean variables such as time mean bed shear stress or flow velocity, while effects of turbulence intensity, e.g., bed shear stress fluctuation, on sediment transport were seldom considered. This may be due to the fact that turbulence fluctuation is relatively limited in laboratory open-channel flows, which are often used for conducting sediment transport experiments. However, turbulence intensity could be markedly enhanced in practice. This note presents an analytical method to compute bed load transport by including effects of fluctuations in the bed shear stress. The analytical results obtained show that the transport rate enhanced by turbulence can be expressed as a simple function of the relative fluctuation of the bed shear stress. The results are also verified using data that were collected recently from specifically designed laboratory experiments. The present analysis is applicable largely for the condition of a flat bed that is comprised of uniform sand particles subject to unidirectional flows.

  18. Modeling bed load transport and step-pool morphology with a reduced-complexity approach

    NASA Astrophysics Data System (ADS)

    Saletti, Matteo; Molnar, Peter; Hassan, Marwan A.; Burlando, Paolo

    2016-04-01

    Steep mountain channels are complex fluvial systems, where classical methods developed for lowland streams fail to capture the dynamics of sediment transport and bed morphology. Estimations of sediment transport based on average conditions have more than one order of magnitude of uncertainty because of the wide grain-size distribution of the bed material, the small relative submergence of coarse grains, the episodic character of sediment supply, and the complex boundary conditions. Most notably, bed load transport is modulated by the structure of the bed, where grains are imbricated in steps and similar bedforms and, therefore, they are much more stable then predicted. In this work we propose a new model based on a reduced-complexity (RC) approach focused on the reproduction of the step-pool morphology. In our 2-D cellular-automaton model entrainment, transport and deposition of particles are considered via intuitive rules based on physical principles. A parsimonious set of parameters allows the control of the behavior of the system, and the basic processes can be considered in a deterministic or stochastic way. The probability of entrainment of grains (and, as a consequence, particle travel distances and resting times) is a function of flow conditions and bed topography. Sediment input is fed at the upper boundary of the channel at a constant or variable rate. Our model yields realistic results in terms of longitudinal bed profiles and sediment transport trends. Phases of aggradation and degradation can be observed in the channel even under a constant input and the memory of the morphology can be quantified with long-range persistence indicators. Sediment yield at the channel outlet shows intermittency as observed in natural streams. Steps are self-formed in the channel and their stability is tested against the model parameters. Our results show the potential of RC models as complementary tools to more sophisticated models. They provide a realistic description of

  19. The impact of benthic fauna on fluvial bed load transport: Challenges of upscaling laboratory experiments to river and landscape scales.

    NASA Astrophysics Data System (ADS)

    Rice, S. P.

    2012-04-01

    The impact on sediment transport processes and channel morphology of several relatively large, iconic animals including beaver and salmon is increasingly well understood. However, many other aquatic fauna are important zoogeomorphic agents and ecosystem engineers. These somewhat overlooked "Cinderella" species include benthic aquatic insect larvae, freshwater crustaceans and many species of fish. Despite relatively modest individual effects, the ubiquity, abundance and cumulative impact of these organisms makes them a potentially significant agency, with as yet undiscovered and unquantified impacts on channel morphology and sediment fluxes. Their actions (digging, foraging, moving, burrowing), constructions and secretions modify bed sediment characteristics (grain size distribution, interlock, imbrication, protrusion), alter bed topography (thence hydraulic roughness) and contribute to biogenic restraints on grain movement. In turn, they can affect the distribution of surface particle entrainment thresholds and bed shear stresses, with implications for bed load transport. Flume experiments have measured some of these impacts and provided direct observations of the mechanisms involved, but many of the most interesting research questions pertain to the impact of these animals at reach, catchment and even landscape scales: Not least, what is the impact of small aquatic animals on bed load flux and yield? This presentation will consider some of the challenges involved in answering this question; that is, of scaling up experimental understanding of how aquatic animals affect bed load transport processes to river scales. Pertinent themes include: (1) the potential impacts of experimental arrangements on the behaviours and activities that affect hydraulic or geomorphological processes; (2) field coincidence of the spatial and temporal distributions of (a) the animals and their behaviours with (b) the physical conditions (substrates, flows) under which those animals are

  20. Correction to "A general power equation for predicting bed load transport rates in gravel bed rivers"

    Treesearch

    Jeffrey J. Barry; John M. Buffington; John G. King

    2007-01-01

    In the paper "A general power equation for predicting bed load transport rates in gravel bed rivers" by Jeffrey J. Barry et al. (Water Resources Research, 40, W10401, doi:10.1029/2004WR003190, 2004), the y axis for Figures 5 and 10 was incorrectly labeled and should have read "log10 (predicted transport) - log10 (observed transport)." In addition,...

  1. Variability of Bed Load Transport During Six Summers of Continuous Measurements in Two Austrian Mountain Streams (Fischbach and Ruetz)

    NASA Astrophysics Data System (ADS)

    Rickenmann, Dieter

    2018-01-01

    Previous measurements of bed load transport in gravel bed streams revealed a large temporal and spatial variability of bed load transport rates. Using an impact plate geophone system, continuous bed load transport measurements were made during 6 years in two mountain streams in Austria. The two streams have a snow-melt and glacier-melt dominated hydrologic regime resulting in frequent transport activity during the summer half year. Periods of days to weeks were identified which are associated with approximately constant Shields values that indicate quasi-stable bed conditions. Between these stable periods, the position of the bed load transport function varied while its steepness remained approximately constant. For integration time scales of several hours to 1 day, the fluctuations in bed load transport decreased and the correlation between bed load transport and water discharge increased. For integration times of about 70-100 days, bed load transport is determined by discharge or shear stress to within a factor of about 2, relative to the 6 year mean level. Bed load texture increased with increasing mean flow strength and mean transport intensity. Weak and predominantly clockwise daily hysteresis of bed load transport was found for the first half of the summer period.

  2. Manual for computing bed load transport using BAGS (Bedload Assessment for Gravel-bed Streams) Software

    Treesearch

    John Pitlick; Yantao Cui; Peter Wilcock

    2009-01-01

    This manual provides background information and instructions on the use of a spreadsheet-based program for Bedload Assessment in Gravel-bed Streams (BAGS). The program implements six bed load transport equations developed specifically for gravel-bed rivers. Transport capacities are calculated on the basis of field measurements of channel geometry, reach-average slope,...

  3. Equal-mobility bed load transport in a small, step-pool channel in the Ouachita Mountains

    Treesearch

    Daniel A. Marion; Frank Weirich

    2003-01-01

    Abstract: Equal-mobility transport (EMT) of bed load is more evident than size-selective transport during near-bankfull flow events in a small, step-pool channel in the Ouachita Mountains of central Arkansas. Bed load transport modes were studied by simulating five separate runoff events with peak discharges between 0.25 and 1.34 m3...

  4. The transition from intermittent to continuous bed-load transport arises from merger of "bursty" transport events

    NASA Astrophysics Data System (ADS)

    Lee, D. B.; Jerolmack, D. J.

    2017-12-01

    Bed-load transport is notoriously unpredictable, in part due to stochastic fluctuations in grain entrainment and deposition. A general statistical mechanical framework has been proposed by Furbish and colleagues to formally derive average bed-load flux from grain-scale motion, and its application requires an intimate understanding of the probabilistic motion of individual grains. Recent work by Ancey et al. suggests that, near threshold, particles are entrained collectively. If so, understanding the scales of correlation is a necessary step to complete the probabilistic framework describing bed-load flux. We perform a series of experiments in a steep-sloped channel that directly quantifies fluctuations in grain motion as a function of the feed rate of particles (marbles). As the feed rate is increased, the necessary averaging time is decreased (i.e. transport grows less variable in time). Collective grain motion is defined as spatially clustered movement of several grains at once. We find that entrainment of particles is generally collective, but that these entrained particles deposit independently of each other. The size distribution of collective motion events follows an exponential decay that is consistent across sediment feed rates. To first order, changing feed rate does not change the kinematics of mobile grains, just the frequency of motion. For transport within a given region of the bed, we show that the total displacement of all entrained grains is proportional to the kinetic energy deposited into the bed by impacting grains. Individual grain-bed impacts are the likely cause of both collective and individual grain entrainment. The picture that emerges is similar to generic avalanching dynamics in sandpiles: "avalanches" (collective entrainment events) of a characteristic size relax with a characteristic timescale regardless of feed rate, but the frequency of avalanches increases in proportion to the feed rate. At high enough feed rates the avalanches merge

  5. Anomalous diffusion for bed load transport with a physically-based model

    NASA Astrophysics Data System (ADS)

    Fan, N.; Singh, A.; Foufoula-Georgiou, E.; Wu, B.

    2013-12-01

    Diffusion of bed load particles shows both normal and anomalous behavior for different spatial-temporal scales. Understanding and quantifying these different types of diffusion is important not only for the development of theoretical models of particle transport but also for practical purposes, e.g., river management. Here we extend a recently proposed physically-based model of particle transport by Fan et al. [2013] to further develop an Episodic Langevin equation (ELE) for individual particle motion which reproduces the episodic movement (start and stop) of sediment particles. Using the proposed ELE we simulate particle movements for a large number of uniform size particles, incorporating different probability distribution functions (PDFs) of particle waiting time. For exponential PDFs of waiting times, particles reveal ballistic motion in short time scales and turn to normal diffusion at long time scales. The PDF of simulated particle travel distances also shows a change in its shape from exponential to Gamma to Gaussian with a change in timescale implying different diffusion scaling regimes. For power-law PDF (with power - μ) of waiting times, the asymptotic behavior of particles at long time scales reveals both super-diffusion and sub-diffusion, however, only very heavy tailed waiting times (i.e. 1.0 < μ < 1.5) could result in sub-diffusion. We suggest that the contrast between our results and previous studies (for e.g., studies based on fractional advection-diffusion models of thin/heavy tailed particle hops and waiting times) results could be due the assumption in those studies that the hops are achieved instantaneously, but in reality, particles achieve their hops within finite times (as we simulate here) instead of instantaneously, even if the hop times are much shorter than waiting times. In summary, this study stresses on the need to rethink the alternative models to the previous models, such as, fractional advection-diffusion equations, for studying

  6. Variation in the reference Shields stress for bed load transport in gravel‐bed streams and rivers

    USGS Publications Warehouse

    Mueller, Erich R.; Pitlick, John; Nelson, Jonathan M.

    2005-01-01

    The present study examines variations in the reference shear stress for bed load transport (τr) using coupled measurements of flow and bed load transport in 45 gravel‐bed streams and rivers. The study streams encompass a wide range in bank‐full discharge (1–2600 m3/s), average channel gradient (0.0003–0.05), and median surface grain size (0.027–0.21 m). A bed load transport relation was formed for each site by plotting individual values of the dimensionless transport rate W* versus the reach‐average dimensionless shear stress τ*. The reference dimensionless shear stress τ*r was then estimated by selecting the value of τ* corresponding to a reference transport rate of W* = 0.002. The results indicate that the discharge corresponding to τ*r averages 67% of the bank‐full discharge, with the variation independent of reach‐scale morphologic and sediment properties. However, values of τ*r increase systematically with average channel gradient, ranging from 0.025–0.035 at sites with slopes of 0.001–0.006 to values greater than 0.10 at sites with slopes greater than 0.02. A corresponding relation for the bank‐full dimensionless shear stress τ*bf, formulated with data from 159 sites in North America and England, mirrors the relation between τ*r and channel gradient, suggesting that the bank‐full channel geometry of gravel‐ and cobble‐bedded streams is adjusted to a relatively constant excess shear stress, τ*bf − τ*r, across a wide range of slopes.

  7. Predicting fractional bed load transport rates: Application of the Wilcock‐Crowe equations to a regulated gravel bed river

    USGS Publications Warehouse

    Gaeuman, David; Andrews, E.D.; Krause, Andreas; Smith, Wes

    2009-01-01

    Bed load samples from four locations in the Trinity River of northern California are analyzed to evaluate the performance of the Wilcock‐Crowe bed load transport equations for predicting fractional bed load transport rates. Bed surface particles become smaller and the fraction of sand on the bed increases with distance downstream from Lewiston Dam. The dimensionless reference shear stress for the mean bed particle size (τ*rm) is largest near the dam, but varies relatively little between the more downstream locations. The relation between τ*rm and the reference shear stresses for other size fractions is constant across all locations. Total bed load transport rates predicted with the Wilcock‐Crowe equations are within a factor of 2 of sampled transport rates for 68% of all samples. The Wilcock‐Crowe equations nonetheless consistently under‐predict the transport of particles larger than 128 mm, frequently by more than an order of magnitude. Accurate prediction of the transport rates of the largest particles is important for models in which the evolution of the surface grain size distribution determines subsequent bed load transport rates. Values of τ*rm estimated from bed load samples are up to 50% larger than those predicted with the Wilcock‐Crowe equations, and sampled bed load transport approximates equal mobility across a wider range of grain sizes than is implied by the equations. Modifications to the Wilcock‐Crowe equation for determining τ*rm and the hiding function used to scale τ*rm to other grain size fractions are proposed to achieve the best fit to observed bed load transport in the Trinity River.

  8. Literature review for Texas Department of Transportation Research Project 0-4695: Guidance for design in areas of extreme bed-load mobility, Edwards Plateau, Texas

    USGS Publications Warehouse

    Heitmuller, Franklin T.; Asquith, William H.; Fang, Xing; Thompson, David B.; Wang, Keh-Han

    2005-01-01

    A review of the literature addressing sediment transport in gravel-bed river systems and structures designed to control bed-load mobility is provided as part of Texas Department of Transportation research project 0–4695: Guidance for Design in Areas of Extreme Bed-Load Mobility. The study area comprises the western half of the Edwards Plateau in central Texas. Three primary foci of the literature review are journal articles, edited volumes, and government publications. Major themes within the body of literature include deterministic sediment transport theory and equations, development of methods to measure and analyze fluvial sediment, applications and development of theory in natural channels and flume experiments, and recommendations for river management and structural design. The literature review provides an outline and foundation for the research project to characterize extreme bed-load mobility in rivers and streams across the study area. The literature review also provides a basis upon which potential modifications to low-water stream-crossing design in the study area can be made.

  9. The Influence of Relative Submergence on the Near-bed Flow Field: Implications for Bed-load Transport

    NASA Astrophysics Data System (ADS)

    Cooper, J.; Tait, S.; Marion, A.

    2005-12-01

    Bed-load is governed by interdependent mechanisms, the most significant being the interaction between bed roughness, surface layer composition and near-bed flow. Despite this, practically all transport rate equations are described as a function of average bed shear stress. Some workers have examined the role of turbulence in sediment transport (Nelson et al. 1995) but have not explored the potential significance of spatial variations in the near-bed flow field. This is unfortunate considering evidence showing that transport is spatially heterogeneous and could be linked to the spatial nature of the near-bed flow (Drake et al., 1988). An understanding is needed of both the temporal and spatial variability in the near-bed flow field. This paper presents detailed spatial velocity measurements of the near-bed flow field over a gravel-bed, obtained using Particle Image Velocimetry. These data have been collected in a laboratory flume under two regimes: (i) tests with one bed slope and different flow depths; and (ii) tests with a combination of flow depths and slopes at the same average bed shear stress. Results indicate spatial variation in the streamwise velocities of up to 45 per cent from the double-averaged velocity (averaged in both time and space). Under both regimes, as the depth increased, spatial variability in the flow field increased. The probability distributions of near-bed streamwise velocities became progressively more skewed towards the higher velocities. This change was more noticeable under regime (i). This has been combined with data from earlier tests in which the near-bed velocity close to an entraining grain was measured using a PIV/image analysis system (Chegini et al, 2002). This along with data on the shape of the probability density function of velocities capable of entraining individual grains derived from a discrete-particle model (Heald et al., 2004) has been used to estimate the distribution of local velocities required for grain motion in

  10. Reply to comment by Claude Michel on "A general power equation for predicting bed load transport rates in gravel bed rivers"

    Treesearch

    Jeffrey J. Barry; John M. Buffington; John G. King

    2005-01-01

    We thank Michel [2005] for the opportunity to improve our bed load transport equation [Barry et al., 2004, equation (6)] and to resolve the dimensional complexity that he identified. However, we do not believe that the alternative bed load transport equation proposed by Michel [2005] provides either the mechanistic insight or predictive power of our transport equation...

  11. Bed load transport and boundary roughness changes as competing causes of hysteresis in the relationship between river discharge and seismic amplitude recorded near a steep mountain stream

    NASA Astrophysics Data System (ADS)

    Roth, Danica L.; Finnegan, Noah J.; Brodsky, Emily E.; Rickenmann, Dieter; Turowski, Jens M.; Badoux, Alexandre; Gimbert, Florent

    2017-05-01

    Hysteresis in the relationship between bed load transport and river stage is a well-documented phenomenon with multiple known causes. Consequently, numerous studies have interpreted hysteresis in the relationship between seismic ground motion near rivers and some measure of flow strength (i.e., discharge or stage) as the signature of bed load transport. Here we test this hypothesis in the Erlenbach stream (Swiss Prealps) using a metric to quantitatively compare hysteresis in seismic data with hysteresis recorded by geophones attached beneath steel plates within the streambed, a well-calibrated proxy for direct sediment transport measurements. We find that while both the geophones and seismometers demonstrate hysteresis, the magnitude and direction of hysteresis are not significantly correlated between these data, indicating that the seismic signal at this site is primarily reflecting hysteresis in processes other than sediment transport. Seismic hysteresis also does not correlate significantly with the magnitude of sediment transport recorded by the geophones, contrary to previous studies' assumptions. We suggest that hydrologic sources and changes in water turbulence, for instance due to evolving boundary conditions at the bed, rather than changes in sediment transport rates, may sometimes contribute to or even dominate the hysteresis observed in seismic amplitudes near steep mountain rivers.Plain Language SummaryAn increasing number of studies have recently observed changes in the amount of seismic shaking (hysteresis) recorded near a river at a given discharge during floods. Most studies have assumed that this hysteresis was caused by changes in the amount of <span class="hlt">sediment</span> being <span class="hlt">transported</span> in the river and have therefore used the hysteresis to assess <span class="hlt">sediment</span> <span class="hlt">transport</span> rates and patterns. We examine concurrent seismic and <span class="hlt">sediment</span> <span class="hlt">transport</span> data from a steep mountain stream in the Swiss Prealps and find that changes in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDR29003V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDR29003V"><span>Highly-resolved numerical simulations of <span class="hlt">bed-load</span> <span class="hlt">transport</span> in a turbulent open-channel flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vowinckel, Bernhard; Kempe, Tobias; Nikora, Vladimir; Jain, Ramandeep; Fröhlich, Jochen</p> <p>2015-11-01</p> <p>The study presents the analysis of phase-resolving Direct Numerical Simulations of a horizontal turbulent open-channel flow laden with a large number of spherical particles. These particles have a mobility close to their threshold of incipient motion andare <span class="hlt">transported</span> in <span class="hlt">bed-load</span> mode. The coupling of the fluid phase with the particlesis realized by an Immersed Boundary Method. The Double-Averaging Methodology is applied for the first time convolutingthe data into a handy set of quantities averaged in time and space to describe the most prominent flow features.In addition, a systematic study elucidatesthe impact of mobility and <span class="hlt">sediment</span> supply on the pattern formation of particle clusters ina very large computational domain. A detailed description of fluid quantities links the developed particle patterns to the enhancement of turbulence and to a modified hydraulic resistance. Conditional averaging isapplied toerosion events providingthe processes involved inincipient particle motion. Furthermore, the detection of moving particle clusters as well as their surrounding flow field is addressedby a a moving frameanalysis. Funded by German Research Foundation (DFG), project FR 1593/5-2, computational time provided by ZIH Dresden, Germany, and JSC Juelich, Germany.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029715','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029715"><span>A method for improving predictions of <span class="hlt">bed-load</span> discharges to reservoirs</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lopes, V.L.; Osterkamp, W.R.; Bravo-Espinosa, M.</p> <p>2007-01-01</p> <p>Effective management options for mitigating the loss of reservoir water storage capacity to <span class="hlt">sedimentation</span> depend on improved predictions of <span class="hlt">bed-load</span> discharges into the reservoirs. Most predictions of <span class="hlt">bed-load</span> discharges, however, are based on the assumption that the rates of <span class="hlt">bed-load</span> <span class="hlt">sediment</span> availability equal the <span class="hlt">transport</span> capacity of the flow, ignoring the spatio-temporal variability of the <span class="hlt">sediment</span> supply. This paper develops a semiquantitative method to characterize <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> in alluvial channels, assuming a channel reach is non-supply limited when the <span class="hlt">bed-load</span> discharge of a given <span class="hlt">sediment</span> particle-size class is functionally related to the energy that is available to <span class="hlt">transport</span> that fraction of the total <span class="hlt">bed-load</span>. The method was applied to 22 alluvial stream channels in the USA to determine whether a channel reach had a supply-limited or non-supply-limited <span class="hlt">bed-load</span> <span class="hlt">transport</span> regime. The non-supply-limited <span class="hlt">transport</span> regime was further subdivided into two groups on the basis of statistical tests. The results indicated the pattern of <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> in alluvial channels depends on the complete spectrum of <span class="hlt">sediment</span> particle sizes available for <span class="hlt">transport</span> rather than individual particle-size fractions represented by one characteristic particle size. The application of the method developed in this paper should assist reservoir managers in selecting <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> equations to improve predictions of <span class="hlt">bed-load</span> discharge in alluvial streams, thereby significantly increasing the efficiency of management options for maintaining the storage capacity of waterbodies. ?? 2007 Blackwell Publishing Asia Pty Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP21A0889F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP21A0889F"><span>Experimental Exploration of Scale Effects and Factors Controlling <span class="hlt">Bed</span> <span class="hlt">Load</span> <span class="hlt">Sediment</span> Entrainment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fathel, S. L.; Furbish, D. J.; Schmeeckle, M. W.</p> <p>2015-12-01</p> <p>Detailed measurements of individual sand grains moving on a streambed allow us to obtain a deeper understanding of the characteristics of incipient motion and evaluate spatial and temporal trends in particle entrainment. We use <span class="hlt">bed</span> <span class="hlt">load</span> particle motions measured from high-speed imaging (250 Hz) of uniform, coarse grained sand from two flume experiments, which have different mean fluid velocities near the bed. Particle tracking reveals more than 6,000 entrainment events in 5 seconds (Run 1) and over 5,000 events in 2 seconds (Run 2). We manually track particles, at sub-pixel resolution, from entrainment to either disentrainment or until the particle leaves the frame. Within these experiments we find that over 90% of all initial motions contain a cross-stream component of motion where approximately a third of the motions may be cross-stream dominated, and furthermore, up to 7% of the motions may be negative (i.e. move backwards). We propose that the variability in the direction of initial motion is, in part, a product of the bed topography, where we find that with increasing mean fluid velocity, the initial motion of the sand particles are less sensitive to bed topography, and are more likely to be dominated by the fluid. The high resolution of this data set, containing positions of particles measured start-to-stop, allows us to calculate the characteristic timescale required for a particle to become streamwise, or fluid, dominated in these systems. We also evaluate these data to further show whether the nature of entrainment is a memoryless, uncorrelated process, a correlated process related to the number of particles already in motion (i.e., possibly reflecting collective entrainment), or some combination of the two. This work suggests that the probability of entrainment depends on physical factors such as bed microtopography and the magnitude of the fluid velocity, in addition to varying with space and time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=328219','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=328219"><span>Acoustic signal propagation and measurement in natural stream channels for application to surrogate <span class="hlt">bed</span> <span class="hlt">load</span> measurements: Halfmoon Creek, Colorado</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Monitoring <span class="hlt">sediment</span>-generated noise using submerged hydrophones is a surrogate method for measuring <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> in streams with the potential for improving estimates of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> through widespread, inexpensive monitoring. Understanding acoustic signal propagation in natural stream e...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRF..120.2529A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRF..120.2529A"><span>Stochastic interpretation of the advection-diffusion equation and its relevance to <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ancey, C.; Bohorquez, P.; Heyman, J.</p> <p>2015-12-01</p> <p>The advection-diffusion equation is one of the most widespread equations in physics. It arises quite often in the context of <span class="hlt">sediment</span> <span class="hlt">transport</span>, e.g., for describing time and space variations in the particle activity (the solid volume of particles in motion per unit streambed area). Phenomenological laws are usually sufficient to derive this equation and interpret its terms. Stochastic models can also be used to derive it, with the significant advantage that they provide information on the statistical properties of particle activity. These models are quite useful when <span class="hlt">sediment</span> <span class="hlt">transport</span> exhibits large fluctuations (typically at low <span class="hlt">transport</span> rates), making the measurement of mean values difficult. Among these stochastic models, the most common approach consists of random walk models. For instance, they have been used to model the random displacement of tracers in rivers. Here we explore an alternative approach, which involves monitoring the evolution of the number of particles moving within an array of cells of finite length. Birth-death Markov processes are well suited to this objective. While the topic has been explored in detail for diffusion-reaction systems, the treatment of advection has received no attention. We therefore look into the possibility of deriving the advection-diffusion equation (with a source term) within the framework of birth-death Markov processes. We show that in the continuum limit (when the cell size becomes vanishingly small), we can derive an advection-diffusion equation for particle activity. Yet while this derivation is formally valid in the continuum limit, it runs into difficulty in practical applications involving cells or meshes of finite length. Indeed, within our stochastic framework, particle advection produces nonlocal effects, which are more or less significant depending on the cell size and particle velocity. Albeit nonlocal, these effects look like (local) diffusion and add to the intrinsic particle diffusion (dispersal due</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=340017','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=340017"><span>Measurement of gravel <span class="hlt">bed</span> <span class="hlt">load</span> using impact plates</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Accurate determinations of the rate of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> are difficult to make but important for determining the fate of <span class="hlt">sediment</span> released after the removal of a dam. Two dams were removed from the Elwha River in the state of Washington beginning in 2011, and 72 impact plates were installed downst...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=310662','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=310662"><span>Passive acoustic monitoring of <span class="hlt">bed</span> <span class="hlt">load</span> for fluvial applications</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The <span class="hlt">sediment</span> <span class="hlt">transported</span> as <span class="hlt">bed</span> <span class="hlt">load</span> in streams and rivers is notoriously difficult to monitor cheaply and accurately. Passive acoustic methods are relatively simple, inexpensive, and provide spatial integration along with high temporal resolution. In 1963 work began on monitoring emissions from par...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdWR..111..156G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdWR..111..156G"><span>A SPH elastic-viscoplastic model for granular flows and <span class="hlt">bed-load</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghaïtanellis, Alex; Violeau, Damien; Ferrand, Martin; Abderrezzak, Kamal El Kadi; Leroy, Agnès; Joly, Antoine</p> <p>2018-01-01</p> <p>An elastic-viscoplastic model (Ulrich, 2013) is combined to a multi-phase SPH formulation (Hu and Adams, 2006; Ghaitanellis et al., 2015) to model granular flows and non-cohesive <span class="hlt">sediment</span> <span class="hlt">transport</span>. The soil is treated as a continuum exhibiting a viscoplastic behaviour. Thus, below a critical shear stress (i.e. the yield stress), the soil is assumed to behave as an isotropic linear-elastic solid. When the yield stress is exceeded, the soil flows and behaves as a shear-thinning fluid. A liquid-solid transition threshold based on the granular material properties is proposed, so as to make the model free of numerical parameter. The yield stress is obtained from Drucker-Prager criterion that requires an accurate computation of the effective stress in the soil. A novel method is proposed to compute the effective stress in SPH, solving a Laplace equation. The model is applied to a two-dimensional soil collapse (Bui et al., 2008) and a dam break over mobile beds (Spinewine and Zech, 2007). Results are compared with experimental data and a good agreement is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRF..117.1037K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRF..117.1037K"><span>A classification scheme for turbulence based on the velocity-intermittency structure with an application to near-wall flow and with implications for <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keylock, C. J.; Nishimura, K.; Peinke, J.</p> <p>2012-03-01</p> <p>Kolmogorov's classic theory for turbulence assumed an independence between velocity increments and the value for the velocity itself. However, recent work has called this assumption in to question, which has implications for the structure of atmospheric, oceanic and fluvial flows. Here we propose a conceptually simple analytical framework for studying velocity-intermittency coupling that is similar in essence to the popular quadrant analysis method for studying near-wall flows. However, we study the dominant (longitudinal) velocity component along with a measure of the roughness of the signal, given mathematically by its series of Hölder exponents. Thus, we permit a possible dependence between velocity and intermittency. We compare boundary layer data obtained in a wind tunnel to turbulent jets and wake flows. These flow classes all have distinct characteristics, which cause them to be readily distinguished using our technique and the results are robust to changes in flow Reynolds numbers. Classification of environmental flows is then possible based on their similarities to the idealized flow classes and we demonstrate this using laboratory data for flow in a parallel-channel confluence. Our results have clear implications for <span class="hlt">sediment</span> <span class="hlt">transport</span> in a range of geophysical applications as they suggest that the recently proposed impulse-based methods for studying <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> are particularly relevant in domains such as gravel bed river flows where the boundary layer is disrupted and wake interactions predominate.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70028332','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70028332"><span>Acoustic bed velocity and <span class="hlt">bed</span> <span class="hlt">load</span> dynamics in a large sand bed river</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gaeuman, D.; Jacobson, R.B.</p> <p>2006-01-01</p> <p>Development of a practical technology for rapid quantification of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> in large rivers would represent a revolutionary advance for <span class="hlt">sediment</span> monitoring and the investigation of fluvial dynamics. Measurement of <span class="hlt">bed</span> <span class="hlt">load</span> motion with acoustic Doppler current profiles (ADCPs) has emerged as a promising approach for evaluating <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>. However, a better understanding of how ADCP data relate to conditions near the stream bed is necessary to make the method practical for quantitative applications. In this paper, we discuss the response of ADCP bed velocity measurements, defined as the near-bed <span class="hlt">sediment</span> velocity detected by the instrument's bottom-tracking feature, to changing <span class="hlt">sediment-transporting</span> conditions in the lower Missouri River. Bed velocity represents a weighted average of backscatter from moving <span class="hlt">bed</span> <span class="hlt">load</span> particles and spectral reflections from the immobile bed. The ratio of bed velocity to mean <span class="hlt">bed</span> <span class="hlt">load</span> particle velocity depends on the concentration of the particles moving in the <span class="hlt">bed</span> <span class="hlt">load</span> layer, the <span class="hlt">bed</span> <span class="hlt">load</span> layer thickness, and the backscatter strength from a unit area of moving particles relative to the echo strength from a unit area of unobstructed bed. A model based on existing <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> theory predicted measured bed velocities from hydraulic and grain size measurements with reasonable success. Bed velocities become more variable and increase more rapidly with shear stress when the <span class="hlt">transport</span> stage, defined as the ratio of skin friction to the critical shear stress for particle entrainment, exceeds a threshold of about 17. This transition in bed velocity response appears to be associated with the appearance of longer, flatter bed forms at high <span class="hlt">transport</span> stages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.5509A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.5509A"><span>The nature and role of advection in advection-diffusion equations used for modelling <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ancey, Christophe; Bohorquez, Patricio; Heyman, Joris</p> <p>2016-04-01</p> <p>The advection-diffusion equation arises quite often in the context of <span class="hlt">sediment</span> <span class="hlt">transport</span>, e.g., for describing time and space variations in the particle activity (the solid volume of particles in motion per unit streambed area). Stochastic models can also be used to derive this equation, with the significant advantage that they provide information on the statistical properties of particle activity. Stochastic models are quite useful when <span class="hlt">sediment</span> <span class="hlt">transport</span> exhibits large fluctuations (typically at low <span class="hlt">transport</span> rates), making the measurement of mean values difficult. We develop an approach based on birth-death Markov processes, which involves monitoring the evolution of the number of particles moving within an array of cells of finite length. While the topic has been explored in detail for diffusion-reaction systems, the treatment of advection has received little attention. We show that particle advection produces nonlocal effects, which are more or less significant depending on the cell size and particle velocity. Albeit nonlocal, these effects look like (local) diffusion and add to the intrinsic particle diffusion (dispersal due to velocity fluctuations), with the important consequence that local measurements depend on both the intrinsic properties of particle displacement and the dimensions of the measurement system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1818317B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1818317B"><span>Lagrangian and Eulerian description of <span class="hlt">bed-load</span> particle kinematics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ballio, Francesco; Sadabadi, Seyed Abbas Hosseini; Pokrajac, Dubravka; Radice, Alessio</p> <p>2016-04-01</p> <p>The motion of <span class="hlt">bed-load</span> <span class="hlt">sediment</span> particles <span class="hlt">transported</span> by a flow can be analyzed within a Lagrangian or an Eulerian framework. In the former case, we consider the particles as individual objects in motion and we study their kinematic properties. The latter approach is instead referred to suitably chosen control volumes. Quantities describing <span class="hlt">sediment</span> motion in the two frameworks are different, and the relationships among the two approaches are not straightforward. In this work, we intend to discuss the kinematic properties of <span class="hlt">sediment</span> <span class="hlt">transport</span>: first, a set of quantities is univocally defined; then, relationships among different representations are explored. Proof-of-concept results presented in the study are from a recent experiment involving weak <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span>, where the moving particles were released over a fixed rough bed. The bulk flow velocity was 1.4 times the critical value for incipient particle motion, and particles were mostly moving by rolling and sliding, with limited saltation. The particle motion was filmed from the top and the measurements were conducted by image-based methods, obtaining extensive samples of virtually-instantaneous quantities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013202','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013202"><span>New approach to calibrating <span class="hlt">bed</span> <span class="hlt">load</span> samplers</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hubbell, D.W.; Stevens, H.H.; Skinner, J.V.; Beverage, J.P.</p> <p>1985-01-01</p> <p>Cyclic variations in <span class="hlt">bed</span> <span class="hlt">load</span> discharge at a point, which are an inherent part of the process of <span class="hlt">bed</span> <span class="hlt">load</span> movement, complicate calibration of <span class="hlt">bed</span> <span class="hlt">load</span> samplers and preclude the use of average rates to define sampling efficiencies. Calibration curves, rather than efficiencies, are derived by two independent methods using data collected with prototype versions of the Helley‐Smith sampler in a large calibration facility capable of continuously measuring <span class="hlt">transport</span> rates across a 9 ft (2.7 m) width. Results from both methods agree. Composite calibration curves, based on matching probability distribution functions of samples and measured rates from different hydraulic conditions (runs), are obtained for six different versions of the sampler. Sampled rates corrected by the calibration curves agree with measured rates for individual runs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ESuD....6..389L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ESuD....6..389L"><span>Advection and dispersion of <span class="hlt">bed</span> <span class="hlt">load</span> tracers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lajeunesse, Eric; Devauchelle, Olivier; James, François</p> <p>2018-05-01</p> <p>We use the erosion-deposition model introduced by Charru et al. (2004) to numerically simulate the evolution of a plume of <span class="hlt">bed</span> <span class="hlt">load</span> tracers entrained by a steady flow. In this model, the propagation of the plume results from the stochastic exchange of particles between the bed and the <span class="hlt">bed</span> <span class="hlt">load</span> layer. We find a transition between two asymptotic regimes. The tracers, initially at rest, are gradually set into motion by the flow. During this entrainment regime, the plume is strongly skewed in the direction of propagation and continuously accelerates while spreading nonlinearly. With time, the skewness of the plume eventually reaches a maximum value before decreasing. This marks the transition to an advection-diffusion regime in which the plume becomes increasingly symmetrical, spreads linearly, and advances at constant velocity. We analytically derive the expressions of the position, the variance, and the skewness of the plume and investigate their asymptotic regimes. Our model assumes steady state. In the field, however, <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> is intermittent. We show that the asymptotic regimes become insensitive to this intermittency when expressed in terms of the distance traveled by the plume. If this finding applies to the field, it might provide an estimate for the average <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018WRR....54..842R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018WRR....54..842R"><span><span class="hlt">Bed</span> <span class="hlt">Load</span> Variability and Morphology of Gravel Bed Rivers Subject to Unsteady Flow: A Laboratory Investigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Redolfi, M.; Bertoldi, W.; Tubino, M.; Welber, M.</p> <p>2018-02-01</p> <p>Measurement and estimation of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> in gravel bed rivers are highly affected by its temporal fluctuations. Such variability is primarily driven by the flow regime but is also associated with a variety of inherent channel processes, such as flow turbulence, grain entrainment, and bed forms migration. These internal and external controls often act at comparable time scales, and are therefore difficult to disentangle, thus hindering the study of <span class="hlt">bed</span> <span class="hlt">load</span> variability under unsteady flow regime. In this paper, we report on laboratory experiments performed in a large, mobile bed flume where typical hydromorphological conditions of gravel bed rivers were reproduced. Data from a large number of replicated runs, including triangular and square-wave hydrographs, were used to build a statistically sound description of <span class="hlt">sediment</span> <span class="hlt">transport</span> processes. We found that the inherent variability of <span class="hlt">bed</span> <span class="hlt">load</span> flux strongly depends on the sampling interval, and it is significantly higher in complex, wandering or braided channels. This variability can be filtered out by computing the mean response over the experimental replicates, which allows us to highlight two distinctive phenomena: (i) an overshooting (undershooting) response of the mean <span class="hlt">bed</span> <span class="hlt">load</span> flux to a sudden increase (decrease) of discharge, and (ii) a clockwise hysteresis in the <span class="hlt">sediment</span> rating curve. We then provide an interpretation of these findings through a conceptual mathematical model, showing how both phenomena are associated with a lagging morphological adaptation to unsteady flow. Overall, this work provides basic information for evaluating, monitoring, and managing gravel <span class="hlt">transport</span> in morphologically active rivers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://repository.uwyo.edu/uwnpsrc_reports/vol30/iss1/5/','USGSPUBS'); return false;" href="http://repository.uwyo.edu/uwnpsrc_reports/vol30/iss1/5/"><span>Measurements of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> on Pacific Creek, Buffalo Fork and The Snake River in Grand Teton National Park, Wyoming</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Erwin, Susannah O.; Schmidt, J.C.</p> <p>2006-01-01</p> <p>Dams disrupt the flow of both of water and <span class="hlt">sediment</span> through a watershed. Channel morphology is a function of discharge and <span class="hlt">sediment</span> load, and perturbations caused by dams often alter channel form, causing significant geomorphic and, potentially, ecological changes (e.g. Petts and Gurnell, 2005). At the first order, dams often produce a flow regime that is profoundly altered in the timing, magnitude, and frequency of flows (Magilligan and Nislow, 2005). Yet, the nature of channel adjustments will be specific to both the physical setting, size of the river, dam characteristics, and nature and severity of the flow regulation (Church 1995; Knighton, 1998).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7864','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7864"><span>Effects of <span class="hlt">sediment</span> <span class="hlt">transport</span> on survival of salmonid embryos in a natural stream: A simulation approach</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas E. Lisle; Jack Lewis</p> <p>1992-01-01</p> <p>A model is presented that simulates the effects of streamflow and <span class="hlt">sediment</span> <span class="hlt">transport</span> on survival of salmonid embryos incubating in spawning gravels in a natural channel. Components of the model include a 6-yr streamflow record, an empirical <span class="hlt">bed</span> <span class="hlt">load-transport</span> function, a relation between <span class="hlt">transport</span> and infiltration of sandy bedload into a gravel bed, effects of fine-...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70120735','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70120735"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> measurements: Chapter 5</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Diplas, P.; Kuhnle, R.; Gray, J.; Glysson, D.; Edwards, T.; García, Marcelo H.</p> <p>2008-01-01</p> <p><span class="hlt">Sediment</span> erosion, <span class="hlt">transport</span>, and deposition in fluvial systems are complex processes that are treated in detail in other sections of this book. Development of methods suitable for the collection of data that contribute to understanding these processes is a still-evolving science. <span class="hlt">Sediment</span> and ancillary data are fundamental requirements for the proper management of river systems, including the design of structures, the determination of aspects of stream behavior, ascertaining the probable effect of removing an existing structure, estimation of bulk erosion, <span class="hlt">transport</span>, and <span class="hlt">sediment</span> delivery to the oceans, ascertaining the long-term usefulness of reservoirs and other public works, tracking movement of solid-phase contaminants, restoration of degraded or otherwise modified streams, and assistance in the calibration and validation of numerical models. This chapter presents techniques for measuring bed-material properties and suspended and <span class="hlt">bed-load</span> discharges. Well-established and relatively recent, yet adequately tested, sampling equipment and methodologies, with designs that are guided by sound physical and statistical principles, are described. Where appropriate, the theory behind the development of the equipment and guidelines for its use are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H33O..08J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H33O..08J"><span>Granular controls on the dispersion of <span class="hlt">bed</span> <span class="hlt">load</span> tracers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jerolmack, D. J.; Martin, R. L.; Phillips, C. B.</p> <p>2014-12-01</p> <p>Coarse particles are <span class="hlt">transported</span> in a river as <span class="hlt">bed</span> <span class="hlt">load</span>, i.e., they move in frequent contact with and are supported by the granular bed. This movement is typically intermittent and may be described by a series of steps are rests, the distributions of which determine particle dispersion. Laboratory and field studies of <span class="hlt">bed</span> <span class="hlt">load</span> tracer dispersion have reported sub- and super-diffusive behavior, both of which have been successfully reproduced with stochastic <span class="hlt">transport</span> models. Although researchers have invoked heavy-tailed step lengths as the cause of anomalous dispersion, most observations report thin-tailed distributions. Little attention has been paid to rest periods, and stochastic <span class="hlt">transport</span> models have not been connected to the underlying mechanics of particle motion. Based on theoretical and experimental evidence, we argue that step lengths are thin-tailed and do not control the longterm dispersion of <span class="hlt">bed</span> <span class="hlt">load</span> tracers; they are determined by momentum balance between the fluid and solid. Using laboratory experiments with both marbles and natural <span class="hlt">sediments</span>, we demonstrate that the rest time distribution is power law, and argue that this distribution controls asymptotic dispersion. Observed rest times far exceed any hydrodynamic timescale. Experiments reveal that rest times of deposited particles are governed by fluctuations in river bed elevation; in particular, the return time for the bed to scour to the base of a deposited particle. Stochastic fluctuations in bed elevation are describable by an Ornstein-Uhlenbeck (mean-reverting random walk) model that contains two parameters, which we show are directly related to the granular shear rate and range of bed elevation fluctuations, respectively. Combining these results with the theory of asymmetric random walks (particles only move downstream), we predict superdiffusive behavior that is in quantitative agreement with our observations of tracer dispersion in a natural river.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9420C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9420C"><span>Measuring the <span class="hlt">Bed</span> <span class="hlt">Load</span> velocity in Laboratory flumes using ADCP and Digital Cameras</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conevski, Slaven; Guerrero, Massimo; Rennie, Colin; Bombardier, Josselin</p> <p>2017-04-01</p> <p>Measuring the <span class="hlt">transport</span> rate and apparent velocity of the bedload is notoriously hard and there is not a certain technique that would obtain continues data. There are many empirical models, based on the estimation of the shear stress, but only few involve direct measurement of the <span class="hlt">bed</span> <span class="hlt">load</span> velocity. The bottom tracking (BT) mode of an acoustic Doppler current profiler (ADCP) has been used many times to estimate the apparent velocity of the <span class="hlt">bed</span> <span class="hlt">load</span>. Herein is the basic idea, to exploit the bias of the BT signal towards the <span class="hlt">bed</span> <span class="hlt">load</span> movement and to calibrate this signal with traditional measuring techniques. These measurements are quite scarce and seldom reliable since there are not taken in controlled conditions. So far, no clear confirmation has been conducted in laboratory-controlled conditions that would attest the assumptions made in the estimation of the apparent <span class="hlt">bed</span> <span class="hlt">load</span> velocity, nor in the calibration of the empirical equations. Therefore, this study explores several experiments under stationary conditions, where the signal of the ADCP BT mode is recorded and compared to the <span class="hlt">bed</span> <span class="hlt">load</span> motion recorded by digital camera videography. The experiments have been performed in the hydraulic laboratories of Ottawa and Bologna, using two different ADCPs and two different high resolution cameras. In total, more then 30 experiments were performed for different <span class="hlt">sediment</span> mixtures and different hydraulic conditions. In general, a good match is documented between the apparent <span class="hlt">bed</span> <span class="hlt">load</span> velocity measured by the ADCP and the videography. The slight deviation in single experiments can be explained by gravel particles inhomogeneity, difficult in reproducing the same hydro-sedimentological conditions and the randomness of the backscattering strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP53A0599T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP53A0599T"><span>A New Method for Tracking Individual Particles During <span class="hlt">Bed</span> <span class="hlt">Load</span> <span class="hlt">Transport</span> in a Gravel-Bed River</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tremblay, M.; Marquis, G. A.; Roy, A. G.; Chaire de Recherche Du Canada En Dynamique Fluviale</p> <p>2010-12-01</p> <p>Many particle tracers (passive or active) have been developed to study gravel movement in rivers. It remains difficult, however, to document resting and moving periods and to know how particles travel from one deposition site to another. Our new tracking method uses the Hobo Pendant G acceleration Data Logger to quantitatively describe the motion of individual particles from the initiation of movement, through the displacement and to the rest, in a natural gravel river. The Hobo measures the acceleration in three dimensions at a chosen temporal frequency. The Hobo was inserted into 11 artificial rocks. The rocks were seeded in Ruisseau Béard, a small gravel-bed river in the Yamaska drainage basin (Québec) where the hydraulics, particle sizes and bed characteristics are well known. The signals recorded during eight floods (Summer and Fall 2008-2009) allowed us to develop an algorithm which classifies the periods of rest and motion. We can differentiate two types of motion: sliding and rolling. The particles can also vibrate while remaining in the same position. The examination of the movement and vibration periods with respect to the hydraulic conditions (discharge, shear stress, stream power) showed that vibration occurred mostly before the rise of hydrograph and allowed us to establish movement threshold and response times. In all cases, particle movements occurred during floods but not always in direct response to increased bed shear stress and stream power. This method offers great potential to track individual particles and to establish a spatiotemporal sequence of the intermittent <span class="hlt">transport</span> of the particle during a flood and to test theories concerning the resting periods of particles on a gravel bed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70021299','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70021299"><span>Predicting boundary shear stress and <span class="hlt">sediment</span> <span class="hlt">transport</span> over bed forms</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McLean, S.R.; Wolfe, S.R.; Nelson, J.M.</p> <p>1999-01-01</p> <p>To estimate <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> rates in flows over bed forms such as ripples and dunes, spatially averaged velocity profiles are frequently used to predict mean boundary shear stress. However, such averaging obscures the complex, nonlinear interaction of wake decay, boundary-layer development, and topographically induced acceleration downstream of flow separation and often leads to inaccurate estimates of boundary stress, particularly skin friction, which is critically important in predicting <span class="hlt">bed-load</span> <span class="hlt">transport</span> rates. This paper presents an alternative methodology for predicting skin friction over 2D bed forms. The approach is based on combining the equations describing the mechanics of the internal boundary layer with semiempirical structure functions to predict the velocity at the crest of a bedform, where the flow is most similar to a uniform boundary layer. Significantly, the methodology is directed toward making specific predictions only at the bed-form crest, and as a result it avoids the difficulty and questionable validity of spatial averaging. The model provides an accurate estimate of the skin friction at the crest where <span class="hlt">transport</span> rates are highest. Simple geometric constraints can be used to derive the mean <span class="hlt">transport</span> rates as long as <span class="hlt">bed</span> <span class="hlt">load</span> is dominant.To estimate <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> rates in flows over bed forms such as ripples and dunes, spatially averaged velocity profiles are frequently used to predict mean boundary shear stress. However, such averaging obscures the complex, nonlinear interaction of wake decay, boundary-layer development, and topographically induced acceleration downstream of flow separation and often leads to inaccurate estimates of boundary stress, particularly skin friction, which is critically important in predicting <span class="hlt">bed-load</span> <span class="hlt">transport</span> rates. This paper presents an alternative methodology for predicting skin friction over 2D bed forms. The approach is based on combining the equations describing the mechanics of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5903904','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5903904"><span>Universal characteristics of particle shape evolution by <span class="hlt">bed-load</span> chipping</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sipos, András Árpád; Shaw, Sam; Sarti, Giovanni; Domokos, Gábor</p> <p>2018-01-01</p> <p>River currents, wind, and waves drive <span class="hlt">bed-load</span> <span class="hlt">transport</span>, in which <span class="hlt">sediment</span> particles collide with each other and Earth’s surface. A generic consequence is impact attrition and rounding of particles as a result of chipping, often referred to in geological literature as abrasion. Recent studies have shown that the rounding of river pebbles can be modeled as diffusion of surface curvature, indicating that geometric aspects of impact attrition are insensitive to details of collisions and material properties. We present data from fluvial, aeolian, and coastal environments and laboratory experiments that suggest a common relation between circularity and mass attrition for particles <span class="hlt">transported</span> as <span class="hlt">bed</span> <span class="hlt">load</span>. Theory and simulations demonstrate that universal characteristics of shape evolution arise because of three constraints: (i) Initial particles are mildly elongated fragments, (ii) particles collide with similarly-sized particles or the bed, and (iii) collision energy is small enough that chipping dominates over fragmentation but large enough that sliding friction is negligible. We show that <span class="hlt">bed-load</span> <span class="hlt">transport</span> selects these constraints, providing the foundation to estimate a particle’s attrition rate from its shape alone in most sedimentary environments. These findings may be used to determine the contribution of attrition to downstream fining in rivers and deserts and to infer <span class="hlt">transport</span> conditions using only images of <span class="hlt">sediment</span> grains. PMID:29670937</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29670937','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29670937"><span>Universal characteristics of particle shape evolution by <span class="hlt">bed-load</span> chipping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Novák-Szabó, Tímea; Sipos, András Árpád; Shaw, Sam; Bertoni, Duccio; Pozzebon, Alessandro; Grottoli, Edoardo; Sarti, Giovanni; Ciavola, Paolo; Domokos, Gábor; Jerolmack, Douglas J</p> <p>2018-03-01</p> <p>River currents, wind, and waves drive <span class="hlt">bed-load</span> <span class="hlt">transport</span>, in which <span class="hlt">sediment</span> particles collide with each other and Earth's surface. A generic consequence is impact attrition and rounding of particles as a result of chipping, often referred to in geological literature as abrasion. Recent studies have shown that the rounding of river pebbles can be modeled as diffusion of surface curvature, indicating that geometric aspects of impact attrition are insensitive to details of collisions and material properties. We present data from fluvial, aeolian, and coastal environments and laboratory experiments that suggest a common relation between circularity and mass attrition for particles <span class="hlt">transported</span> as <span class="hlt">bed</span> <span class="hlt">load</span>. Theory and simulations demonstrate that universal characteristics of shape evolution arise because of three constraints: (i) Initial particles are mildly elongated fragments, (ii) particles collide with similarly-sized particles or the bed, and (iii) collision energy is small enough that chipping dominates over fragmentation but large enough that sliding friction is negligible. We show that <span class="hlt">bed-load</span> <span class="hlt">transport</span> selects these constraints, providing the foundation to estimate a particle's attrition rate from its shape alone in most sedimentary environments. These findings may be used to determine the contribution of attrition to downstream fining in rivers and deserts and to infer <span class="hlt">transport</span> conditions using only images of <span class="hlt">sediment</span> grains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP34A..06J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP34A..06J"><span><p>Universal shape evolution of particles by <span class="hlt">bed-load</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jerolmack, D. J.; Domokos, G.; Shaw, S.; Sipos, A.; Szabo, T.</p> <p>2016-12-01</p> <p>River currents, wind and waves drive <span class="hlt">bed-load</span> <span class="hlt">transport</span>, in which <span class="hlt">sediment</span> particles collide with each other and the Earth's surface. A generic consequence is erosion and rounding of particles as a result of chipping, often referred to in geological literature as abrasion. Recent studies have shown that the erosion of river pebbles can be modeled as diffusion of surface curvature, indicating that geometric aspects of chipping erosion are insensitive to details of collisions and material properties. Here we present data from fluvial, aeolian and coastal environments that suggest a universal relation between particle circularity and mass lost due to <span class="hlt">bed-load</span> chipping. Simulations and experiments support the diffusion model and demonstrate that three constraints are required to produce this universal curve: (i) initial particles are fragments; (ii) erosion is dominated by collisions among like-sized particles; and (iii) collision energy is small enough that chipping dominates over fragmentation. We show that the mechanics of bedrock weathering and <span class="hlt">bed-load</span> <span class="hlt">transport</span> select these constraints, providing the foundation to estimate a particle's erosion rate from its shape alone in most sedimentary environments. These findings may be used to determine the contribution of chipping to downstream fining in rivers and deserts, and to infer <span class="hlt">transport</span> conditions using only images of <span class="hlt">sediment</span> grains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7840','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7840"><span>Particle size variations between <span class="hlt">bed</span> <span class="hlt">load</span> and bed material in natural gravel bed channels</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas E. Lisle</p> <p>1995-01-01</p> <p>Abstract - Particle sizes of <span class="hlt">bed</span> <span class="hlt">load</span> and bed material that represent materials <span class="hlt">transported</span> and stored over a period of years are used to investigate selective <span class="hlt">transport</span> in 13 previously sampled, natural gravel bed channels. The ratio (D*) of median particle size of bed material to the <span class="hlt">transport</span>- and frequency-weighted mean of median <span class="hlt">bed</span> <span class="hlt">load</span> size decreases to unity...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRF..117.1014M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRF..117.1014M"><span>Using multiple <span class="hlt">bed</span> <span class="hlt">load</span> measurements: Toward the identification of bed dilation and contraction in gravel-bed rivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marquis, G. A.; Roy, A. G.</p> <p>2012-02-01</p> <p>This study examines <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> processes in a small gravel-bed river (Béard Creek, Québec) using three complementary methods: bed elevation changes between successive floods, bed activity surveys using tags inserted into the bed, and <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rates from <span class="hlt">bed</span> <span class="hlt">load</span> traps. The analysis of 20 flood events capable of mobilizing bed material led to the identification of divergent results among the methods. In particular, bed elevation changes were not consistent with the bed activity surveys. In many cases, bed elevation changes were significant (1 to 2 times the D50) even if the bed surface had not been activated during the flood, leading to the identification of processes of bed dilation and contraction that occurred over 10% to 40% of the bed surface. These dynamics of the river bed prevent accurate derivation of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rates from topographic changes, especially for low magnitude floods. This paper discusses the mechanisms that could explain the dilation and contraction of particles within the bed and their implications in fluvial dynamics. Bed contraction seems to be the result of the winnowing of the fine <span class="hlt">sediments</span> under very low gravel <span class="hlt">transport</span>. Bed dilation seems to occur on patches of the bed at the threshold of motion where various processes such as fine <span class="hlt">sediment</span> infiltration lead to the maintenance of a larger <span class="hlt">sediment</span> framework volume. Both processes are also influenced by flood history and the initial local bed state and in turn may have a significant impact on <span class="hlt">sediment</span> <span class="hlt">transport</span> and morphological changes in gravel-bed rivers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.8443P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.8443P"><span>The Impact of Urbanization on Temporal Changes in <span class="hlt">Sediment</span> <span class="hlt">Transport</span> in a Gravel Bed Channel in Southern Ontario, Canada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plumb, B. D.; Annable, W. K.; Thompson, P. J.; Hassan, M. A.</p> <p>2017-10-01</p> <p>A field investigation has been undertaken to characterize the event-based <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> dynamics of a highly urbanized gravel bed stream. A combination of direct <span class="hlt">bed</span> <span class="hlt">load</span> and tracer particle measurements were taken over a 3 year period during which time approximately 30 <span class="hlt">sediment</span> mobilizing events occurred. <span class="hlt">Sediment</span> <span class="hlt">transport</span> measurements were used to calibrate a fractional <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> model and combined with hydrometric data which represent four different land use conditions (ranging from rural to highly urbanized) to analyze the differences in discharge magnitude and frequency and its impact on <span class="hlt">sediment</span> <span class="hlt">transport</span>. Fractional <span class="hlt">transport</span> analysis of the <span class="hlt">bed</span> <span class="hlt">load</span> measurements indicates that frequent intermediate discharge events can mobilize sand and fine gravel to an approximate equally mobile condition, however, the <span class="hlt">transport</span> rates at these discharges exhibit greater variability than at discharges above the bankfull discharge. Path lengths of the coarse fraction, measured using tracer clasts, are insensitive to peak discharge, and instead <span class="hlt">transport</span> at distances less than those reported in other gravel bed channels, which is attributed to the shorter duration discharge events common to urban streams. The magnitude-frequency analysis reveals that the frequency, time, and volume of competent <span class="hlt">sediment</span> mobilizing events are increasing with urbanization. Variability in effective discharges suggests that a range of discharges, spanning between frequent, low magnitude events to less frequent, high magnitude events are geomorphically significant. However, trends in the different land use scenarios suggest that urbanization is shifting the geomorphic significance toward more frequent, lower magnitude events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.9325S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.9325S"><span>Temporal variability and memory in <span class="hlt">sediment</span> <span class="hlt">transport</span> in an experimental step-pool channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saletti, Matteo; Molnar, Peter; Zimmermann, André; Hassan, Marwan A.; Church, Michael</p> <p>2015-11-01</p> <p>Temporal dynamics of <span class="hlt">sediment</span> <span class="hlt">transport</span> in steep channels using two experiments performed in a steep flume (8%) with natural <span class="hlt">sediment</span> composed of 12 grain sizes are studied. High-resolution (1 s) time series of <span class="hlt">sediment</span> <span class="hlt">transport</span> were measured for individual grain-size classes at the outlet of the flume for different combinations of <span class="hlt">sediment</span> input rates and flow discharges. Our aim in this paper is to quantify (a) the relation of discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> and (b) the nature and strength of memory in grain-size-dependent <span class="hlt">transport</span>. None of the simple statistical descriptors of <span class="hlt">sediment</span> <span class="hlt">transport</span> (mean, extreme values, and quantiles) display a clear relation with water discharge, in fact a large variability between discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> is observed. Instantaneous <span class="hlt">transport</span> rates have probability density functions with heavy tails. <span class="hlt">Bed</span> <span class="hlt">load</span> bursts have a coarser grain-size distribution than that of the entire experiment. We quantify the strength and nature of memory in <span class="hlt">sediment</span> <span class="hlt">transport</span> rates by estimating the Hurst exponent and the autocorrelation coefficient of the time series for different grain sizes. Our results show the presence of the Hurst phenomenon in <span class="hlt">transport</span> rates, indicating long-term memory which is grain-size dependent. The short-term memory in coarse grain <span class="hlt">transport</span> increases with temporal aggregation and this reveals the importance of the sampling duration of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rates in natural streams, especially for large fractions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034436','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034436"><span>Evaluation of ADCP apparent <span class="hlt">bed</span> <span class="hlt">load</span> velocity in a large sand-bed river: Moving versus stationary boat conditions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jamieson, E.C.; Rennie, C.D.; Jacobson, R.B.; Townsend, R.D.</p> <p>2011-01-01</p> <p>Detailed mapping of bathymetry and apparent <span class="hlt">bed</span> <span class="hlt">load</span> velocity using a boat-mounted acoustic Doppler current profiler (ADCP) was carried out along a 388-m section of the lower Missouri River near Columbia, Missouri. Sampling transects (moving boat) were completed at 5- and 20-m spacing along the study section. Stationary (fixed-boat) measurements were made by maintaining constant boat position over a target point where the position of the boat did not deviate more than 3 m in any direction. For each transect and stationary measurement, apparent <span class="hlt">bed</span> <span class="hlt">load</span> velocity (vb) was estimated using ADCP bottom tracking data and high precision real-time kinematic (RTK) global positioning system (GPS). The principal objectives of this research are to (1) determine whether boat motion introduces a bias in apparent <span class="hlt">bed</span> <span class="hlt">load</span> velocity measurements; and (2) evaluate the reliability of ADCP bed velocity measurements for a range of <span class="hlt">sediment</span> <span class="hlt">transport</span> environments. Results indicate that both high <span class="hlt">transport</span> (vb>0.6 m/s) and moving-boat conditions (for both high and low <span class="hlt">transport</span> environments) increase the relative variability in estimates of mean bed velocity. Despite this, the spatially dense single-transect measurements were capable of producing detailed bed velocity maps that correspond closely with the expected pattern of <span class="hlt">sediment</span> <span class="hlt">transport</span> over large dunes. ?? 2011 American Society of Civil Engineers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.8105F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.8105F"><span>Input-variable sensitivity assessment for <span class="hlt">sediment</span> <span class="hlt">transport</span> relations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández, Roberto; Garcia, Marcelo H.</p> <p>2017-09-01</p> <p>A methodology to assess input-variable sensitivity for <span class="hlt">sediment</span> <span class="hlt">transport</span> relations is presented. The Mean Value First Order Second Moment Method (MVFOSM) is applied to two <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> equations showing that it may be used to rank all input variables in terms of how their specific variance affects the overall variance of the <span class="hlt">sediment</span> <span class="hlt">transport</span> estimation. In sites where data are scarce or nonexistent, the results obtained may be used to (i) determine what variables would have the largest impact when estimating <span class="hlt">sediment</span> loads in the absence of field observations and (ii) design field campaigns to specifically measure those variables for which a given <span class="hlt">transport</span> equation is most sensitive; in sites where data are readily available, the results would allow quantifying the effect that the variance associated with each input variable has on the variance of the <span class="hlt">sediment</span> <span class="hlt">transport</span> estimates. An application of the method to two <span class="hlt">transport</span> relations using data from a tropical mountain river in Costa Rica is implemented to exemplify the potential of the method in places where input data are limited. Results are compared against Monte Carlo simulations to assess the reliability of the method and validate its results. For both of the <span class="hlt">sediment</span> <span class="hlt">transport</span> relations used in the sensitivity analysis, accurate knowledge of <span class="hlt">sediment</span> size was found to have more impact on <span class="hlt">sediment</span> <span class="hlt">transport</span> predictions than precise knowledge of other input variables such as channel slope and flow discharge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP53B1029F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP53B1029F"><span>Large sized non-uniform <span class="hlt">sediment</span> <span class="hlt">transport</span> at high capacity on steep slopes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, X.; Zhang, L.; Duan, J. G.</p> <p>2015-12-01</p> <p><span class="hlt">Transport</span> of large-sized particles such as cobbles in steep streams still remains poorly understood in spite of its importance in mountain stream morphdynamics. Here we explored the law of cobble <span class="hlt">transport</span> and the effect of cobble existence on gravel bed material <span class="hlt">transport</span>, using flume experiments with a steep slope (4.9%) and water and <span class="hlt">sediment</span> constantly supplying. The experiments were conducted in an 8 m long and 0.6 m wide circulating flume with the maximal size up to 90 mm and cobble concentrations in the <span class="hlt">sediment</span> bed ranging from 22 percent to 6 percent. The <span class="hlt">sediment</span> <span class="hlt">transport</span> rate is on the order of 1000 g/m/s, which could be taken as high rate <span class="hlt">transport</span> compared with existing researches. <span class="hlt">Bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rate and flow variables were measured after the flume reached an equilibrium state. Bed surface topography was also measured by applying Kinect range camera before and after each run in order to analyze the fractal characteristics of the bed surface under different flow conditions. Critical shear stress of each size friction was estimated from the reference <span class="hlt">transport</span> method (RTM) and a new hiding function was recommended. Preliminary results show that the bed was nearly in an equal mobility <span class="hlt">transport</span> regime. We then plot dimensionless fractional <span class="hlt">transport</span> rate versus dimensionless shear stress and assess the existing <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> formulas of non-uniform <span class="hlt">sediments</span> for their applicability at high <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity. This study contributes to the comprehension of high rate <span class="hlt">sediment</span> <span class="hlt">transport</span> on steep slopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006CSR....26.1826P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006CSR....26.1826P"><span>Sensitivity analysis of non-cohesive <span class="hlt">sediment</span> <span class="hlt">transport</span> formulae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pinto, Lígia; Fortunato, André B.; Freire, Paula</p> <p>2006-10-01</p> <p>Sand <span class="hlt">transport</span> models are often based on semi-empirical equilibrium <span class="hlt">transport</span> formulae that relate <span class="hlt">sediment</span> fluxes to physical properties such as velocity, depth and characteristic <span class="hlt">sediment</span> grain sizes. In engineering applications, errors in these physical properties affect the accuracy of the <span class="hlt">sediment</span> fluxes. The present analysis quantifies error propagation from the input physical properties to the <span class="hlt">sediment</span> fluxes, determines which ones control the final errors, and provides insight into the relative strengths, weaknesses and limitations of four total load formulae (Ackers and White, Engelund and Hansen, van Rijn, and Karim and Kennedy) and one <span class="hlt">bed</span> <span class="hlt">load</span> formulation (van Rijn). The various sources of uncertainty are first investigated individually, in order to pinpoint the key physical properties that control the errors. Since the strong non-linearity of most sand <span class="hlt">transport</span> formulae precludes analytical approaches, a Monte Carlo method is validated and used in the analysis. Results show that the accuracy in total <span class="hlt">sediment</span> <span class="hlt">transport</span> evaluations is mainly determined by errors in the current velocity and in the <span class="hlt">sediment</span> median grain size. For the <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> using the van Rijn formula, errors in the current velocity alone control the final accuracy. In a final set of tests, all physical properties are allowed to vary simultaneously in order to analyze the combined effect of errors. The combined effect of errors in all the physical properties is then compared to an estimate of the errors due to the intrinsic limitations of the formulae. Results show that errors in the physical properties can be dominant for typical uncertainties associated with these properties, particularly for small depths. A comparison between the various formulae reveals that the van Rijn formula is more sensitive to basic physical properties. Hence, it should only be used when physical properties are known with precision.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA480943','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA480943"><span>Community <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Model</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2007-01-01</p> <p>Woods Hole, MA 02543-1598 Phone: (508) 457-2269 Fax: (508) 457-2310 email: csherwood@usgs.gov Timothy Keen Naval Research Laboratory, Code...intended to be used as both a research tool and for practical applications. An accurate and useful model will require coupling <span class="hlt">sediment-transport</span> with...and time steps range from seconds to minutes. We include higher-resolution <span class="hlt">sediment</span>- <span class="hlt">transport</span> calculation modules for research problems but, for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Geomo.277..251H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Geomo.277..251H"><span>Toward a unifying constitutive relation for <span class="hlt">sediment</span> <span class="hlt">transport</span> across environments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Houssais, Morgane; Jerolmack, Douglas J.</p> <p>2017-01-01</p> <p>Landscape evolution models typically parse the environment into different process domains, each with its own <span class="hlt">sediment</span> <span class="hlt">transport</span> law: e.g., soil creep, landslides and debris flows, and river <span class="hlt">bed-load</span> and suspended-<span class="hlt">sediment</span> <span class="hlt">transport</span>. <span class="hlt">Sediment</span> <span class="hlt">transport</span> in all environments, however, contains many of the same physical ingredients, albeit in varying proportions: grain entrainment due to a shear force, that is a combination of fluid flow, particle-particle friction and gravity. We present a new take on the perspective originally advanced by Bagnold, that views the long profile of a hillsope-river-shelf system as a continuous gradient of decreasing granular friction dominance and increasing fluid drag dominance on <span class="hlt">transport</span> capacity. Recent advances in understanding the behavior and regime transitions of dense granular systems suggest that the entire span of granular-to-fluid regimes may be accommodated by a single-phase rheology. This model predicts a material-flow effective friction (or viscosity) that changes with the degree of shear rate and confining pressure. We present experimental results confirming that fluid-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> follows this same rheology, for bed and suspended load. Surprisingly, below the apparent threshold of motion we observe that <span class="hlt">sediment</span> particles creep, in a manner characteristic of glassy systems. We argue that this mechanism is relevant for both hillslopes and rivers. We discuss the possibilities of unifying <span class="hlt">sediment</span> <span class="hlt">transport</span> across environments and disciplines, and the potential consequences for modeling landscape evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AcGeo..60.1493B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AcGeo..60.1493B"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> mechanics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ballio, Francesco; Tait, Simon</p> <p>2012-12-01</p> <p>The Editor of Acta Geophysica and the Guest Editors wish to dedicate this Topical Issue on <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Mechanics to the memory of Stephen Coleman, who died recently. During his career, Stephen had made an outstanding scientific contribution to the topic of <span class="hlt">Sediment</span> <span class="hlt">Transport</span>. The level of his contribution is demonstrated in the paper by Aberle, Coleman, and Nikora included in this issue, on which he started working before becoming aware of the illness that led to his untimely death. For scholars and colleagues Stephen remains an example of intellectual honesty and scientific insight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28784943','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28784943"><span>Image-based Lagrangian Particle Tracking in <span class="hlt">Bed-load</span> Experiments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Radice, Alessio; Sarkar, Sankar; Ballio, Francesco</p> <p>2017-07-20</p> <p>Image analysis has been increasingly used for the measurement of river flows due to its capabilities to furnish detailed quantitative depictions at a relatively low cost. This manuscript describes an application of particle tracking velocimetry (PTV) to a <span class="hlt">bed-load</span> experiment with lightweight <span class="hlt">sediment</span>. The key characteristics of the investigated <span class="hlt">sediment</span> <span class="hlt">transport</span> conditions were the presence of a covered flow and of a fixed rough bed above which particles were released in limited number at the flume inlet. Under the applied flow conditions, the motion of the individual <span class="hlt">bed-load</span> particles was intermittent, with alternating movement and stillness terms. The flow pattern was preliminarily characterized by acoustic measurements of vertical profiles of the stream-wise velocity. During process visualization, a large field of view was obtained using two action-cameras placed at different locations along the flume. The experimental protocol is described in terms of channel calibration, experiment realization, image pre-processing, automatic particle tracking, and post-processing of particle track data from the two cameras. The presented proof-of-concept results include probability distributions of the particle hop length and duration. The achievements of this work are compared to those of existing literature to demonstrate the validity of the protocol.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016WRR....52.9274R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016WRR....52.9274R"><span>A generalized threshold model for computing <span class="hlt">bed</span> <span class="hlt">load</span> grain size distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Recking, Alain</p> <p>2016-12-01</p> <p>For morphodynamic studies, it is important to compute not only the <span class="hlt">transported</span> volumes of <span class="hlt">bed</span> <span class="hlt">load</span>, but also the size of the <span class="hlt">transported</span> material. A few <span class="hlt">bed</span> <span class="hlt">load</span> equations compute fractional <span class="hlt">transport</span> (i.e., both the volume and grain size distribution), but many equations compute only the bulk <span class="hlt">transport</span> (a volume) with no consideration of the <span class="hlt">transported</span> grain sizes. To fill this gap, a method is proposed to compute the <span class="hlt">bed</span> <span class="hlt">load</span> grain size distribution separately to the <span class="hlt">bed</span> <span class="hlt">load</span> flux. The method is called the Generalized Threshold Model (GTM), because it extends the flow competence method for threshold of motion of the largest <span class="hlt">transported</span> grain size to the full bed surface grain size distribution. This was achieved by replacing dimensional diameters with their size indices in the standard hiding function, which offers a useful framework for computation, carried out for each indices considered in the range [1, 100]. New functions are also proposed to account for partial <span class="hlt">transport</span>. The method is very simple to implement and is sufficiently flexible to be tested in many environments. In addition to being a good complement to standard bulk <span class="hlt">bed</span> <span class="hlt">load</span> equations, it could also serve as a framework to assist in analyzing the physics of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> in future research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.7536F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.7536F"><span>Modeling <span class="hlt">sediment</span> <span class="hlt">transport</span> with an integrated view of the biofilm effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fang, H. W.; Lai, H. J.; Cheng, W.; Huang, L.; He, G. J.</p> <p>2017-09-01</p> <p>Most natural <span class="hlt">sediment</span> is invariably covered by biofilms in reservoirs and lakes, which have significant influence on bed form dynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span>, and also play a crucial role in natural river evolution, pollutant <span class="hlt">transport</span>, and habitat changes. However, most models for <span class="hlt">sediment</span> <span class="hlt">transport</span> are based on experiments using clean <span class="hlt">sediments</span> without biological materials. In this study, a three-dimensional mathematical model of hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> is presented with a comprehensive consideration of the biofilm effects. The changes of the bed resistance mainly due to the different bed form dynamics of the biofilm-coated <span class="hlt">sediment</span> (biosediment), which affect the hydrodynamic characteristics, are considered. Moreover, the variations of parameters related to <span class="hlt">sediment</span> <span class="hlt">transport</span> after the biofilm growth are integrated, including the significant changes of the incipient velocity, settling velocity, reference concentration, and equilibrium <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rate. The proposed model is applied to evaluate the effects of biofilms on the hydrodynamic characteristics and <span class="hlt">sediment</span> <span class="hlt">transport</span> in laboratory experiments. Results indicate that the mean velocity increases after the biofilm growth, and the turbulence intensity near the river bed decreases under the same flow condition. Meanwhile, biofilm inhibits <span class="hlt">sediment</span> from moving independently. Thus, the moderate erosion is observed for biosediment resulting in smaller suspended <span class="hlt">sediment</span> concentrations. The proposed model can reasonably reflect these <span class="hlt">sediment</span> <span class="hlt">transport</span> characteristics with biofilms, and the approach to integration of the biological impact could also be used in other modeling of <span class="hlt">sediment</span> <span class="hlt">transport</span>, which can be further applied to provide references for the integrated management of natural aqueous systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2005/5246/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2005/5246/"><span>Use of <span class="hlt">sediment</span> rating curves and optical backscatter data to characterize <span class="hlt">sediment</span> <span class="hlt">transport</span> in the Upper Yuba River watershed, California, 2001-03</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Curtis, Jennifer A.; Flint, Lorraine E.; Alpers, Charles N.; Wright, Scott A.; Snyder, Noah P.</p> <p>2006-01-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> in the upper Yuba River watershed, California, was evaluated from October 2001 through September 2003. This report presents results of a three-year study by the U.S. Geological Survey, in cooperation with the California Ecosystem Restoration Program of the California Bay-Delta Authority and the California Resources Agency. Streamflow and suspended-<span class="hlt">sediment</span> concentration (SSC) samples were collected at four gaging stations; however, this report focuses on <span class="hlt">sediment</span> <span class="hlt">transport</span> at the Middle Yuba River (11410000) and the South Yuba River (11417500) gaging stations. Seasonal suspended-<span class="hlt">sediment</span> rating curves were developed using a group-average method and non-linear least-squares regression. <span class="hlt">Bed-load</span> <span class="hlt">transport</span> relations were used to develop <span class="hlt">bed-load</span> rating curves, and <span class="hlt">bed-load</span> measurements were collected to assess the accuracy of these curves. Annual suspended-<span class="hlt">sediment</span> loads estimated using seasonal SSC rating curves were compared with previously published annual loads estimated using the Graphical Constituent Loading Analysis System (GCLAS). The percent difference ranged from -85 percent to +54 percent and averaged -7.5 percent. During water year 2003 optical backscatter sensors (OBS) were installed to assess event-based suspended-<span class="hlt">sediment</span> <span class="hlt">transport</span>. Event-based suspended-<span class="hlt">sediment</span> loads calculated using seasonal SSC rating curves were compared with loads calculated using calibrated OBS output. The percent difference ranged from +50 percent to -369 percent and averaged -79 percent. The estimated average annual <span class="hlt">sediment</span> yield at the Middle Yuba River (11410000) gage (5 tons/mi2) was significantly lower than that estimated at the South Yuba River (11417500) gage (14 tons/mi2). In both rivers, <span class="hlt">bed</span> <span class="hlt">load</span> represented 1 percent or less of the total annual load throughout the project period. Suspended <span class="hlt">sediment</span> at the Middle Yuba River (11410000) and South Yuba River (11417500) gages was typically greater than 85 percent silt and clay during water year 2003, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ir.uiowa.edu/uisie/34/','USGSPUBS'); return false;" href="http://ir.uiowa.edu/uisie/34/"><span>The measurement of total <span class="hlt">sediment</span> load in alluvial streams</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Benedict, P.C.; Matejka, D.Q.; McNown, John S.; Boyer, M.C.</p> <p>1953-01-01</p> <p>The measurement of the total <span class="hlt">sediment</span> load <span class="hlt">transported</span> by streams that flow in alluvial channels has been a perplexing problem to engineers and geologists for over a century. Until the last decade the development of equipment to measure <span class="hlt">bed</span> <span class="hlt">load</span> and suspended load was carried on almost independently, and without primary consideration of the fundamental laws governing the <span class="hlt">transportation</span> of fluvial <span class="hlt">sediments</span>. French investigators during the nineteenth century described methods of measurement and a mathematical approach for computing the rate of <span class="hlt">bed-load</span> movement. The comprehensive laboratory investigations by Gilbert early in this century provided data that are still being used for studies of <span class="hlt">sediment</span> <span class="hlt">transport</span>. Detailed laboratory investigations of <span class="hlt">bed-load</span> movement conducted during the last two decades by a number of investigators have resulted in the development of additional mathematical formulas for computing rates of <span class="hlt">bed-load</span> movement. Likewise, studies of turbulent flow have provided the turbulence suspension theory for suspended <span class="hlt">sediment</span> as it is known today.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhFl...25j6601B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhFl...25j6601B"><span>Inclined, collisional <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berzi, Diego; Fraccarollo, Luigi</p> <p>2013-10-01</p> <p>We apply the constitutive relations of kinetic theory of granular gases to the <span class="hlt">transport</span> of cohesionless <span class="hlt">sediments</span> driven by a gravitational liquid turbulent stream in steady uniform conditions. The <span class="hlt">sediment</span>-laden flow forms self-equilibrated mechanisms of resistance at the bed surface, below which the <span class="hlt">sediments</span> are at rest. This geo-physical process takes place quite often in streams at moderate slope and may be interpreted through tools common to fluid mechanics and particle physics. Taking into account the viscous dissipation of the fluctuation energy of the particles, and using approximate methods of integration of the governing differential equations, permit to obtain a set of simple formulas for predicting how depths and flow rates adjust to the angle of inclination of the bed, without requiring additional tuning parameters besides the particle and fluid properties. The agreement with laboratory experiments performed with either plastic cylinders or gravel in water is remarkable. We also provide quantitative criteria to determine the range of validity of the theory, i.e., the values of the Shields number and the angle of inclination of the bed for which the particle stresses can be mostly ascribed to collisional exchange of momentum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25751296','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25751296"><span>Onset of <span class="hlt">sediment</span> <span class="hlt">transport</span> is a continuous transition driven by fluid shear and granular creep.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Houssais, Morgane; Ortiz, Carlos P; Durian, Douglas J; Jerolmack, Douglas J</p> <p>2015-03-09</p> <p>Fluid-sheared granular <span class="hlt">transport</span> sculpts landscapes and undermines infrastructure, yet predicting the onset of <span class="hlt">sediment</span> <span class="hlt">transport</span> remains notoriously unreliable. For almost a century, this onset has been treated as a discontinuous transition at which hydrodynamic forces overcome gravity-loaded grain-grain friction. Using a custom laminar-shear flume to image slow granular dynamics deep into the bed, here we find that the onset is instead a continuous transition from creeping to granular flow. This transition occurs inside the dense granular bed at a critical viscous number, similar to granular flows and colloidal suspensions and inconsistent with hydrodynamic frameworks. We propose a new phase diagram for <span class="hlt">sediment</span> <span class="hlt">transport</span>, where '<span class="hlt">bed</span> <span class="hlt">load</span>' is a dense granular flow bounded by creep below and suspension above. Creep is characteristic of disordered solids and reminiscent of soil diffusion on hillslopes. Results provide new predictions for the onset and dynamics of <span class="hlt">sediment</span> <span class="hlt">transport</span> that challenge existing models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/8646','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/8646"><span>A new model for <span class="hlt">bed</span> <span class="hlt">load</span> sampler calibration to replace the probability-matching method</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Robert B. Thomas; Jack Lewis</p> <p>1993-01-01</p> <p>In 1977 extensive data were collected to calibrate six Helley-Smith <span class="hlt">bed</span> <span class="hlt">load</span> samplers with four <span class="hlt">sediment</span> particle sizes in a flume at the St. Anthony Falls Hydraulic Laboratory at the University of Minnesota. Because sampler data cannot be collected at the same time and place as ""true"" trap measurements, the ""probability-matching...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRF..119..621A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRF..119..621A"><span>Using repeat lidar to estimate <span class="hlt">sediment</span> <span class="hlt">transport</span> in a steep stream</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, Scott; Pitlick, John</p> <p>2014-03-01</p> <p><span class="hlt">Sediment</span> fluxes in steep mountain streams remain difficult to quantify, despite their importance in geomorphology, ecology, and hazard analysis. In this work, aerial lidar surveys, acquired in 2002, 2008, and 2012, are used to quantify such fluxes in Tahoma Creek, a proglacial stream on Mount Rainier, Washington. As these surveys encompass all coarse <span class="hlt">sediment</span> sources in the basin, we are able to translate geomorphic change into total bed material <span class="hlt">transport</span> volumes for the time steps between surveys. By assuming that the relationship between daily <span class="hlt">sediment</span> <span class="hlt">transport</span> and daily mean discharge is of the form Qs=a(Q-Qc)b, our two observed total loads and estimates of daily mean discharge allow us to numerically solve for values of a and b to create a bed material <span class="hlt">sediment</span> rating curve. Comparisons of our <span class="hlt">transport</span> estimates with <span class="hlt">sediment</span> deposition in a downstream reservoir indicate that our <span class="hlt">transport</span> estimates and derived rating curve are reasonable. The method we present thus represents a plausible means of estimating <span class="hlt">transport</span> rates in energetic settings or during extreme events, applicable whenever at least two cumulative <span class="hlt">sediment</span> loads and the driving hydrology are known. We use these results to assess the performance of several <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> equations. The equations generally overpredict <span class="hlt">transport</span> at low to moderate flows but significantly underpredict <span class="hlt">transport</span> rates during an extreme event. Using a critical shear stress value appropriate for steep streams improves agreement at lower flows, whereas a shear-partitioning technique accounting for form drag losses significantly underpredicts <span class="hlt">transport</span> at all flows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800061637&hterms=River+Erosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DRiver%2BErosion','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800061637&hterms=River+Erosion&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DRiver%2BErosion"><span>Modes of <span class="hlt">sediment</span> <span class="hlt">transport</span> in channelized water flows with ramifications to the erosion of the Martian outflow channels</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Komar, P. D.</p> <p>1980-01-01</p> <p>The paper discusses application to Martian water flows of the criteria that determine which grain-size ranges are <span class="hlt">transported</span> as <span class="hlt">bed</span> <span class="hlt">load</span>, suspension, and wash load. The results show nearly all sand-sized material and finer would have been <span class="hlt">transported</span> as wash load and that basalt pebbles and even cobbles could have been <span class="hlt">transported</span> at rapid rates of suspension. An analysis of the threshold of <span class="hlt">sediment</span> motion on Mars further indicates that the flows would have been highly competent, the larger flows having been able to <span class="hlt">transport</span> boulder-sized material. Comparisons with terrestrial rivers which <span class="hlt">transport</span> hyperconcentration levels of <span class="hlt">sediments</span> suggest that the Martian water flows could have achieved <span class="hlt">sediment</span> concentrations up to 70% in weight. Although it is possible that flows could have picked up enough <span class="hlt">sediment</span> to convert to pseudolaminar mud flows, they probably remained at hyperconcentration levels and fully turbulent in flow character.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70192860','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70192860"><span>Numerical simulation of large-scale <span class="hlt">bed</span> <span class="hlt">load</span> particle tracer advection-dispersion in rivers with free bars</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Iwasaki, Toshiki; Nelson, Jonathan M.; Shimizu, Yasuyuki; Parker, Gary</p> <p>2017-01-01</p> <p>Asymptotic characteristics of the <span class="hlt">transport</span> of <span class="hlt">bed</span> <span class="hlt">load</span> tracer particles in rivers have been described by advection-dispersion equations. Here we perform numerical simulations designed to study the role of free bars, and more specifically single-row alternate bars, on streamwise tracer particle dispersion. In treating the conservation of tracer particle mass, we use two alternative formulations for the Exner equation of <span class="hlt">sediment</span> mass conservation: the flux-based formulation, in which bed elevation varies with the divergence of the <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rate, and the entrainment-based formulation, in which bed elevation changes with the net deposition rate. Under the condition of no net bed aggradation/degradation, a 1-D flux-based deterministic model that does not describe free bars yields no streamwise dispersion. The entrainment-based 1-D formulation, on the other hand, models stochasticity via the probability density function (PDF) of particle step length, and as a result does show tracer dispersion. When the formulation is generalized to 2-D to include free alternate bars, however, both models yield almost identical asymptotic advection-dispersion characteristics, in which streamwise dispersion is dominated by randomness inherent in free bar morphodynamics. This randomness can result in a heavy-tailed PDF of waiting time. In addition, migrating bars may constrain the travel distance through temporary burial, causing a thin-tailed PDF of travel distance. The superdiffusive character of streamwise particle dispersion predicted by the model is attributable to the interaction of these two effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRF..122..847I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRF..122..847I"><span>Numerical simulation of large-scale <span class="hlt">bed</span> <span class="hlt">load</span> particle tracer advection-dispersion in rivers with free bars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwasaki, Toshiki; Nelson, Jonathan; Shimizu, Yasuyuki; Parker, Gary</p> <p>2017-04-01</p> <p>Asymptotic characteristics of the <span class="hlt">transport</span> of <span class="hlt">bed</span> <span class="hlt">load</span> tracer particles in rivers have been described by advection-dispersion equations. Here we perform numerical simulations designed to study the role of free bars, and more specifically single-row alternate bars, on streamwise tracer particle dispersion. In treating the conservation of tracer particle mass, we use two alternative formulations for the Exner equation of <span class="hlt">sediment</span> mass conservation: the flux-based formulation, in which bed elevation varies with the divergence of the <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> rate, and the entrainment-based formulation, in which bed elevation changes with the net deposition rate. Under the condition of no net bed aggradation/degradation, a 1-D flux-based deterministic model that does not describe free bars yields no streamwise dispersion. The entrainment-based 1-D formulation, on the other hand, models stochasticity via the probability density function (PDF) of particle step length, and as a result does show tracer dispersion. When the formulation is generalized to 2-D to include free alternate bars, however, both models yield almost identical asymptotic advection-dispersion characteristics, in which streamwise dispersion is dominated by randomness inherent in free bar morphodynamics. This randomness can result in a heavy-tailed PDF of waiting time. In addition, migrating bars may constrain the travel distance through temporary burial, causing a thin-tailed PDF of travel distance. The superdiffusive character of streamwise particle dispersion predicted by the model is attributable to the interaction of these two effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913693M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913693M"><span>Fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> in a glacier-fed high-mountain river (Riffler Bach, Austrian Alps)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morche, David; Weber, Martin; Faust, Matthias; Schuchardt, Anne; Baewert, Henning</p> <p>2017-04-01</p> <p>High-alpine environments are strongly affected by glacier retreat since the Little Ice Age (LIA). Due to ongoing climate change the hydrology of proglacial rivers is also influenced. It is expected that the growing proportions of snow melt and rainfall events will change runoff characteristics of proglacial rivers. Additionally, the importance of paraglacial <span class="hlt">sediment</span> sources in recently deglaciating glacier forefields is increasing, while the role of glacial erosion is declining. Thus complex environmental conditions leading to a complex pattern of fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> in partly glaciated catchments of the European Alps. Under the umbrella of the joint PROSA-project the fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> of the river Riffler Bach (Kaunertal, Tyrol, Austria) was studied in 3 consecutive ablation seasons in order to quantify <span class="hlt">sediment</span> yields. In June 2012 a probe for water level and an automatic water sampler (AWS) were installed at the outlet of the catchment (20km2). In order to calculate annual stage-discharge-relations by the rating-curve approach, discharge (Q) was repeatedly measured with current meters and by salt dilution. Concurrent to the discharge measurements <span class="hlt">bed</span> <span class="hlt">load</span> was collected using a portable Helley-Smith sampler. <span class="hlt">Bed</span> <span class="hlt">load</span> samples were weighted and sieved in the laboratory to gain annual <span class="hlt">bed</span> <span class="hlt">load</span> rating curves and grain size distributions. In total 564 (2012: 154, 2013: 209, 2014: 201) water samples were collected and subsequently filtered to quantify suspended <span class="hlt">sediment</span> concentrations (SSC). Q-SSC-relations were calculated for single flood events due to the high variability of suspended <span class="hlt">sediment</span> <span class="hlt">transport</span>. The results show a high inter- and intra-annual variability of solid fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span>, which can be explained by the characteristics of suspended <span class="hlt">sediment</span> <span class="hlt">transport</span>. Only 13 of 22 event-based Q-SSC-relations show causal dependency. In 2012, during a period with multiple pluvial-induced peak discharges most <span class="hlt">sediment</span> was <span class="hlt">transported</span>. On the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511033O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511033O"><span>The influence of <span class="hlt">sediment</span> <span class="hlt">transport</span> rate on the development of structure in gravel bed rivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ockelford, Annie; Rice, Steve; Powell, Mark; Reid, Ian; Nguyen, Thao; Tate, Nick; Wood, Jo</p> <p>2013-04-01</p> <p>Although adjustments of surface grain size are known to be strongly influenced by <span class="hlt">sediment</span> <span class="hlt">transport</span> rate little work has systematically explored how different <span class="hlt">transport</span> rates can affect the development of surface structure in gravel bed rivers. Specifically, it has been well established that the <span class="hlt">transport</span> of mixed sized <span class="hlt">sediments</span> leads to the development of a coarser surface or armour layer which occurs over larger areas of the gravel bed. Armour layer development is known to moderate overall <span class="hlt">sediment</span> <span class="hlt">transport</span> rate as well as being extremely sensitive to changes in applied shear stress. However, during this armouring process a bed is created where, smaller gain scale changes, to the bed surface are also apparent such as the development of pebble clusters and imbricate structures. Although these smaller scale changes affect the overall surface grain size distribution very little their presence has the ability to significantly increase the surface stability and hence alter overall <span class="hlt">sediment</span> <span class="hlt">transport</span> rates. Consequently, the interplay between the moderation of <span class="hlt">transport</span> rate as a function of surface coarsening at a larger scale and moderation of <span class="hlt">transport</span> rate as a function of the development of structure on the bed surface at the smaller scale is complicated and warrants further investigation. During experiments a unimodal grain size distribution (σg = 1.30, D50 = 8.8mm) was exposed to 3 different levels of constant discharge that produced <span class="hlt">sediment</span> <span class="hlt">transport</span> conditions ranging from marginal <span class="hlt">transport</span> to conditions approaching full mobility of all size fractions. <span class="hlt">Sediment</span> was re-circulated during the experiments surface grain size distribution <span class="hlt">bed</span> <span class="hlt">load</span> and fractional <span class="hlt">transport</span> rates were measured at a high temporal resolution such that the time evolution of the beds could be fully described. Discussion concentrates on analysing the effects of the evolving bed condition <span class="hlt">sediment</span> <span class="hlt">transport</span> rate (capacity) and <span class="hlt">transported</span> grain size (competence). The outcome of this</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS.983a2032A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS.983a2032A"><span>Distribution of basic <span class="hlt">sediments</span> (bedload <span class="hlt">transport</span>) on changes in coastal coastline Donggala, Central Sulawesi Province, Indonesia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amiruddin</p> <p>2018-03-01</p> <p>This study entitled "Distribution of Bedload <span class="hlt">Transport</span> Against Coastline Changes in Donggala Coast", the formulation of the problem (1) how much of the estimated bedload <span class="hlt">transport</span> in Donggala Bodies; (2) where were the location of erosion and <span class="hlt">sedimentation</span> strong point based on the estimation of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>; (3) the extent to which the prediction of shoreline change rate of <span class="hlt">transport</span> of <span class="hlt">sediments</span> in coastal areas Donggala. This study aims to: (1) the calculation of estimated <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> in Donggala waters; (2) determining the location of the point of erosion and <span class="hlt">sedimentation</span> strong basis of estimated bedload <span class="hlt">transport</span>; (3) the prediction of shoreline change rate of <span class="hlt">transport</span> of <span class="hlt">sediments</span> in coastal areas Donggala.The survey method used in this research to collect primary data include: (1) decision point waypoint coordinates of each location of measurement; (2) measurement of height, period and direction of the waves; (3) a large measurement of <span class="hlt">sediment</span> <span class="hlt">transport</span>; (4) The angle measurement coastline, angle of attack and wave direction, and secondary data include: (1) information from the public; (2) the physical condition data field. The results showed that: (1) general estimate <span class="hlt">sediment</span> <span class="hlt">transport</span> base in each location data collection is varied. This is due to the different points of the coastline as well as the angle of attack of the shoreline waters broke Donggala; (2) strong abrasion at the study site occurs at the point Ts4 (622.75 m3/yr) and TS11 (755.25 m3/yr) located in the Village Tosale and point Tw7 and Tw17 (649.25 m3/yr) in Village of Towale. As for the strong <span class="hlt">sedimentation</span> occurs at the point Ts3 (450.50 m3/yr) located in the Village Tosale and Tg3 point (357.75 m3/yr) located in the Village Tolonggano; (3) of the predicted outcome coastline changes based on the input data estimate <span class="hlt">sediment</span> <span class="hlt">transport</span>, beaches and waves parameters is seen that the changes in the location prophyl coastline tends toward research into or undergo a process of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRF..122..807F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRF..122..807F"><span><span class="hlt">Bed</span> <span class="hlt">load</span> tracer mobility in a mixed bedrock/alluvial channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferguson, R. I.; Sharma, B. P.; Hodge, R. A.; Hardy, R. J.; Warburton, J.</p> <p>2017-04-01</p> <p>The presence of bare or partially covered rock in an otherwise alluvial river implies a downstream change in <span class="hlt">transport</span> capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged tracer clasts to investigate <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> during the same sequence of floods in fully alluvial, bare rock, and partial-cover reaches of an upland stream. High-flow shear stresses in different reaches were calculated by using stage loggers. Tracers seeded in the upstream alluvial channel moved more slowly than elsewhere until the frontrunners reached bare rock and sped up. Tracers seeded on bare rock moved rapidly off it and accumulated just upstream from, and later in, a partial-cover zone with many boulders. The backwater effect of the boulder-rich zone is significant in reducing tracer mobility. Tracer movement over full or partial <span class="hlt">sediment</span> cover was size selective but dispersion over bare rock was not. Along-channel changes in tracer mobility are interpreted in terms of measured differences in shear stress and estimated differences in threshold stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP53A0723M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP53A0723M"><span>Effects of <span class="hlt">Sediment</span> Patches on <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Predictions in Steep Mountain Channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monsalve Sepulveda, A.; Yager, E.</p> <p>2013-12-01</p> <p>Bed surface patches occur in most gravel-bedded rivers and in steep streams can be divided between relatively immobile boulders and more mobile patches of cobbles and gravel. This spatial variability in grain size, roughness and sorting impact <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> by altering the relative local mobility of different grain sizes and creating complex local flow fields. Large boulders also bear a significant part of the total shear stress and we hypothesize that the remaining shear stress on a given mobile patch is a distribution of values that depend on the local topography, patch type and location relative to the large roughness elements and thalweg. Current <span class="hlt">sediment</span> <span class="hlt">transport</span> equations do not account for the variation in roughness, local flow and grain size distributions on and between patches and often use an area-weighted approach to obtain a representative grain size distribution and reach-averaged shear stress. Such equations also do not distinguish between active (patches where at least one grain size is in motion) and inactive patches or include the difference in mobility between patch classes as result of spatial shear stress distributions. To understand the effects of <span class="hlt">sediment</span> patches on <span class="hlt">sediment</span> <span class="hlt">transport</span> in steep channels, we calculated the shear stress distributions over a range of patch classes in a 10% gradient step-pool stream. We surveyed the bed with a high density resolution (every 5 cm in horizontal and vertical directions over a 40 m long reach) using a total station and terrestrial LiDAR, mapped and classified patches by their grain size distributions, and measured water surface elevations and mean velocities for low to moderate flow events. Using these data we calibrated a quasi-three dimensional model (FaSTMECH) to obtain shear stress distributions over each patch for a range of flow discharges. We modified Parker's (1990) equations to use the calculated shear stress distribution, measured grain sizes, and a specific hiding function for each</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H52C..08J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H52C..08J"><span>Rice piles and sticky deltas: <span class="hlt">Sediment</span> <span class="hlt">transport</span> fluctuations in threshold-dominated systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jerolmack, D. J.</p> <p>2008-12-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> is an intermittent process. Even under perfectly steady boundary conditions, <span class="hlt">sediment</span> flux in systems as diverse as rivers and rice piles undergoes wild fluctuations as a result of the inherent nonlinear dynamics of <span class="hlt">transport</span>. This variability confounds geologic interpretation and prediction: "mean" <span class="hlt">transport</span> rates may be dominated by rare but extreme events such that short-term measurements are not directly comparable to longer-time integrated measurements; autogenic (internally-generated) erosion and depositon events may be mistaken for changes in climate and tectonics where their temporal and spatial scales overlap; and <span class="hlt">sediment</span> <span class="hlt">transport</span> may act as a nonlinear filter that obliterates signals of environmental forcing. <span class="hlt">Sediment</span> <span class="hlt">transport</span> fluctuations generally result from slow storage and rapid release of <span class="hlt">sediment</span> within the <span class="hlt">transport</span> system itself. We hypothesize that the presence of a strong process threshold, and a high degree of internal friction (or "stickiness"), are sufficient conditions to generate intermittent <span class="hlt">sediment</span> <span class="hlt">transport</span> behavior. We present experimental data showing similarities in <span class="hlt">transport</span> fluctuations from three very different systems: gravel <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> in a large flume, avalanching in a table-top pile of rice, and shoreline migration in an experimental river delta. Numerical models of a rice pile and an avulsing river delta reproduce these fluctuations, and are used to explore both their origin and also their influence on environmental perturbations. We impose an environmental perturbation on our model systems in the form of cyclically-varying <span class="hlt">sediment</span> supply. Physical and numerical experiments demonstrate that when the timescale of environmental forcing overlaps with the timescales of autogenic <span class="hlt">sediment</span> <span class="hlt">transport</span> fluctuations, the input signal is obliterated and cannot be detected in <span class="hlt">sediment</span> output from the system. We also demonstrate how variability in <span class="hlt">transport</span> introduces a dependence of mean <span class="hlt">transport</span> rate on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRF..122.2411L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRF..122.2411L"><span>The Importance of Splat Events to the Spatiotemporal Structure of Near-Bed Fluid Velocity and <span class="hlt">Bed</span> <span class="hlt">Load</span> Motion Over Bed Forms: Laboratory Experiments Downstream of a Backward Facing Step</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leary, K. C. P.; Schmeeckle, M. W.</p> <p>2017-12-01</p> <p>Flow separation/reattachment on the lee side of alluvial bed forms is known to produce a complex turbulence field, but the spatiotemporal details of the associated patterns of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">sediment</span> <span class="hlt">transported</span> remain largely unknown. Here we report turbulence-resolving, simultaneous measurements of <span class="hlt">bed</span> <span class="hlt">load</span> motion and near-bed fluid velocity downstream of a backward facing step in a laboratory flume. Two synchronized high-speed video cameras simultaneously observed <span class="hlt">bed</span> <span class="hlt">load</span> motion and the motion of neutrally buoyant particles in a laser light sheet 6 mm above the bed at 250 frames/s downstream of a 3.8 cm backward facing step. Particle Imaging Velocimetry (PIV) and Acoustic Doppler Velocimetry (ADV) were used to characterize fluid turbulent patterns, while manual particle tracking techniques were used to characterize <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>. Octant analysis, conducted using ADV data, coupled with Markovian sequence probability analysis highlights differences in the flow near reattachment versus farther downstream. Near reattachment, three distinct flow patterns are apparent. Farther downstream we see the development of a dominant flow sequence. Localized, intermittent, high-magnitude <span class="hlt">transport</span> events are more apparent near flow reattachment. These events are composed of streamwise and cross-stream fluxes of comparable magnitudes. <span class="hlt">Transport</span> pattern and fluid velocity data are consistent with the existence of permeable "splat events," wherein a volume of fluid moves toward and impinges on the bed (sweep) causing a radial movement of fluid in all directions around the point of impingement (outward interaction). This is congruent with flow patterns, identified with octant analysis, proximal to flow reattachment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/24629','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/24629"><span>Maintenance of an obstruction-forced pool in a gravel-bed channel: streamflow, channel morphology, and <span class="hlt">sediment</span> <span class="hlt">transport</span>.</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Richard D. Woodsmith; Marwan A. Hassan</p> <p>2005-01-01</p> <p>Maintenance of pool morphology in a stream channel with a mobile bed requires hydraulic conditions at moderate to high flows that route <span class="hlt">bed</span> <span class="hlt">load</span> through the pool as it is delivered from upstream. Through field measurements of discharge, vertical velocity profiles, <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>, and streambed scour, fill, and grain-size distribution, we found that maintenance of a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP53B0795P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP53B0795P"><span>Filtering mountain landscapes and hydrology through <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Phillips, C. B.; Jerolmack, D. J.</p> <p>2013-12-01</p> <p>Long-term denudation of landscapes is balanced, and sometimes limited by, the <span class="hlt">sediment</span> mass flux leaving the system through rivers. Suspended <span class="hlt">sediment</span> represents the largest fraction of mass exiting the landscape, however coarse <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> may be the rate-limiting process of landscape denudation through its control on bedrock channel erosion and incision. We present research linking particle mechanics for a coarse alluvial gravel stream at the flood scale to particle dynamics at the annual timescale, and examine the implications of these results on channel geometry and the hydrology of mountain rivers. We examine the <span class="hlt">transport</span> dynamics of individual cobbles tagged with passive radio transponder tags from the Mameyes River in the Luquillo Mountains of Puerto Rico, in both bedrock and alluvial stretches. These data are composed of measured 'flight' lengths for each <span class="hlt">transported</span> particle, the fraction of tagged particles mobilized, and high-resolution river stage measurements. At the single flood scale, measured tracer particle flight lengths are exponentially distributed, and modal flight lengths scale linearly with excess shear velocity (U*-U*c). This is in quantitative agreement with recent theory and laboratory experiments, suggesting that moving particles' velocity is determined by momentum balance with the fluid. Examining tracer displacement at long timescales we use a dimensionless impulse (I*) - obtained by integrating the cumulative excess shear velocity over the duration of a flood (normalized by grain size) - and find that the mean travel distance collapses onto a linear relationship. Data show that partial <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> with intermittent motion is the dominant mode for the duration of record. Examining flood statistics, we find that the frequency-magnitude distribution of shear velocity is a power law; however, this scaling is truncated at the threshold of motion, beyond which it displays exponential scaling. The thin-tailed scaling of (U</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019469','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019469"><span>Evaluation of process errors in <span class="hlt">bed</span> <span class="hlt">load</span> sampling using a Dune Model</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gomez, Basil; Troutman, Brent M.</p> <p>1997-01-01</p> <p>Reliable estimates of the streamwide <span class="hlt">bed</span> <span class="hlt">load</span> discharge obtained using sampling devices are dependent upon good at-a-point knowledge across the full width of the channel. Using field data and information derived from a model that describes the geometric features of a dune train in terms of a spatial process observed at a fixed point in time, we show that sampling errors decrease as the number of samples collected increases, and the number of traverses of the channel over which the samples are collected increases. It also is preferable that <span class="hlt">bed</span> <span class="hlt">load</span> sampling be conducted at a pace which allows a number of bed forms to pass through the sampling cross section. The situations we analyze and simulate pertain to moderate <span class="hlt">transport</span> conditions in small rivers. In such circumstances, <span class="hlt">bed</span> <span class="hlt">load</span> sampling schemes typically should involve four or five traverses of a river, and the collection of 20–40 samples at a rate of five or six samples per hour. By ensuring that spatial and temporal variability in the <span class="hlt">transport</span> process is accounted for, such a sampling design reduces both random and systematic errors and hence minimizes the total error involved in the sampling process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816314S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816314S"><span>Towards a better understanding on how large wood is controlling longitudinal <span class="hlt">sediment</span> (dis)connectivity in mountain streams - concepts and first results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schuchardt, Anne; Pöppl, Ronald; Morche, David</p> <p>2016-04-01</p> <p>Large wood (LW) provides various ecological and morphological functions. Recent research has focused on habitat diversity and abundance, effects on channel planforms, pool formation, flow regimes and increased storage of organic matter as well as storage of fine <span class="hlt">sediment</span>. While LW studies and <span class="hlt">sediment</span> <span class="hlt">transport</span> rates are the focus of numerous research questions, the influence of large channel blocking barriers (e.g. LW) and their impact on <span class="hlt">sediment</span> trapping and decoupling <span class="hlt">transportation</span> pathways is less studied. This project tries to diminish the obvious gap and deals with the modifications of the <span class="hlt">sediment</span> connectivity by LW. To investigate the influence of large wood on <span class="hlt">sediment</span> <span class="hlt">transporting</span> processes and <span class="hlt">sediment</span> connectivity, the spatial distribution and characterization of LW (>1 m in length and >10 cm in diameter) in channels is examined by field mapping and dGPS measurements. Channel hydraulic parameters are determined by field measurements of channel long profiles and cross sections. To quantify the direct effects of LW on discharge and <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> the flow velocity and <span class="hlt">bed</span> <span class="hlt">load</span> up- and downstream of LW is measured using an Ott-Nautilus and a portable Helley-Smith <span class="hlt">bed</span> <span class="hlt">load</span> sampler during different water stages. <span class="hlt">Sediment</span> storages behind LWD accumulations will be monitored with dGPS. While accumulation of <span class="hlt">sediment</span> indicates in-channel <span class="hlt">sediment</span> storage and thus disconnection from downstream <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>, erosion of <span class="hlt">sediment</span> evidences downstream <span class="hlt">sediment</span> connectivity. First results will be presented from two study areas in mountain ranges in Germany (Wetterstein Mountain Range) and Austria (Bohemian Massif).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRF..114.2005N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRF..114.2005N"><span>Response of bed surface patchiness to reductions in <span class="hlt">sediment</span> supply</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelson, Peter A.; Venditti, Jeremy G.; Dietrich, William E.; Kirchner, James W.; Ikeda, Hiroshi; Iseya, Fujiko; Sklar, Leonard S.</p> <p>2009-06-01</p> <p>River beds are often arranged into patches of similar grain size and sorting. Patches can be distinguished into "free patches," which are zones of sorted material that move freely, such as <span class="hlt">bed</span> <span class="hlt">load</span> sheets; "forced patches," which are areas of sorting forced by topographic controls; and "fixed patches" of bed material rendered immobile through localized coarsening that remain fairly persistent through time. Two sets of flume experiments (one using bimodal, sand-rich <span class="hlt">sediment</span> and the other using unimodal, sand-free <span class="hlt">sediment</span>) are used to explore how fixed and free patches respond to stepwise reductions in <span class="hlt">sediment</span> supply. At high <span class="hlt">sediment</span> supply, migrating <span class="hlt">bed</span> <span class="hlt">load</span> sheets formed even in unimodal, sand-free <span class="hlt">sediment</span>, yet grain interactions visibly played a central role in their formation. In both sets of experiments, reductions in supply led to the development of fixed coarse patches, which expanded at the expense of finer, more mobile patches, narrowing the zone of active <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> and leading to the eventual disappearance of migrating <span class="hlt">bed</span> <span class="hlt">load</span> sheets. Reductions in <span class="hlt">sediment</span> supply decreased the migration rate of <span class="hlt">bed</span> <span class="hlt">load</span> sheets and increased the spacing between successive sheets. One-dimensional morphodynamic models of river channel beds generally are not designed to capture the observed variability, but should be capable of capturing the time-averaged character of the channel. When applied to our experiments, a 1-D morphodynamic model (RTe-bookAgDegNormGravMixPW.xls) predicted the <span class="hlt">bed</span> <span class="hlt">load</span> flux well, but overpredicted slope changes and was unable to predict the substantial variability in <span class="hlt">bed</span> <span class="hlt">load</span> flux (and load grain size) because of the migration of mobile patches. Our results suggest that (1) the distribution of free and fixed patches is primarily a function of <span class="hlt">sediment</span> supply, (2) the dynamics of <span class="hlt">bed</span> <span class="hlt">load</span> sheets are primarily scaled by <span class="hlt">sediment</span> supply, (3) channels with reduced <span class="hlt">sediment</span> supply may inherently be unable to <span class="hlt">transport</span> <span class="hlt">sediment</span> uniformly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=30610&Lab=ORD&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=30610&Lab=ORD&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>MODELING FINE <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> IN ESTUARIES</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A <span class="hlt">sediment</span> <span class="hlt">transport</span> model (<span class="hlt">SEDIMENT</span> IIIA) was developed to assist in predicting the fate of chemical pollutants sorbed to cohesive <span class="hlt">sediments</span> in rivers and estuaries. Laboratory experiments were conducted to upgrade an existing two-dimensional, depth-averaged, finite element, coh...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13B1606Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13B1606Y"><span>A New Measure for <span class="hlt">Transported</span> Suspended <span class="hlt">Sediment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Q.</p> <p>2017-12-01</p> <p>Non-uniform suspended <span class="hlt">sediment</span> plays an important role in many geographical and biological processes. Despite extensive study, understanding to it seems to stagnate when times to consider non-uniformity and non-equilibrium scenarios comes. Due to unsatisfactory reproducibility, large-scaled flume seems to be incompetent to conduct more fundamental research in this area. To push the realm a step further, experiment to find how suspended <span class="hlt">sediment</span> exchanges is conducted in a new validated equipment, in which turbulence is motivated by oscillating grids. Analysis shows that 1) suspended <span class="hlt">sediment</span> exchange is constrained by ωS invariance, 2) ωS of the suspended <span class="hlt">sediment</span> that certain flow regime could support is unique regardless of the <span class="hlt">sediment</span> gradation and 3) the more turbulent the flow, the higher ωS of the suspension the flow could achieve. A new measure for suspended <span class="hlt">sediment</span> ωS, the work required to sustain <span class="hlt">sediment</span> in suspension <span class="hlt">transport</span> mode if multiplied by gravitational acceleration, is thus proposed to better describe the dynamics of <span class="hlt">transported</span> suspended <span class="hlt">sediment</span>. Except for the further understanding towards suspended <span class="hlt">sediment</span> <span class="hlt">transportation</span> mechanics, with this energy measure, a strategy to distribute total <span class="hlt">transport</span> capacity to different fractions could be derived and rational calculation of non-uniform <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity under non-equilibrium conditions be possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GMD....10.4367C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GMD....10.4367C"><span>SedFoam-2.0: a 3-D two-phase flow numerical model for <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chauchat, Julien; Cheng, Zhen; Nagel, Tim; Bonamy, Cyrille; Hsu, Tian-Jian</p> <p>2017-11-01</p> <p>In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for <span class="hlt">sediment</span> <span class="hlt">transport</span> applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics) toolbox OpenFOAM. In this approach the <span class="hlt">sediment</span> phase is modeled as a continuum, and constitutive laws have to be prescribed for the <span class="hlt">sediment</span> stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for <span class="hlt">sediment</span> <span class="hlt">transport</span>: a simple mixing length model (one-dimensional configuration only), a k - ɛ, and a k - ω model. The numerical implementation is demonstrated on four test cases: <span class="hlt">sedimentation</span> of suspended particles, laminar <span class="hlt">bed</span> <span class="hlt">load</span>, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent <span class="hlt">sediment</span> <span class="hlt">transport</span> problems with different combinations of intergranular stress and turbulence models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70176333','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70176333"><span>Uncertainty in tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jaffe, Bruce E.; Goto, Kazuhisa; Sugawara, Daisuke; Gelfenbaum, Guy R.; La Selle, SeanPaul M.</p> <p>2016-01-01</p> <p>Erosion and deposition from tsunamis record information about tsunami hydrodynamics and size that can be interpreted to improve tsunami hazard assessment. We explore sources and methods for quantifying uncertainty in tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling. Uncertainty varies with tsunami, study site, available input data, <span class="hlt">sediment</span> grain size, and model. Although uncertainty has the potential to be large, published case studies indicate that both forward and inverse tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> models perform well enough to be useful for deciphering tsunami characteristics, including size, from deposits. New techniques for quantifying uncertainty, such as Ensemble Kalman Filtering inversion, and more rigorous reporting of uncertainties will advance the science of tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling. Uncertainty may be decreased with additional laboratory studies that increase our understanding of the semi-empirical parameters and physics of tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span>, standardized benchmark tests to assess model performance, and development of hybrid modeling approaches to exploit the strengths of forward and inverse models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989JGR....9414287P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989JGR....9414287P"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> processes in estuaries: An introduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perillo, Gerardo M. E.; Lavelle, J. William</p> <p>1989-10-01</p> <p>Research on estuarine <span class="hlt">sediment</span> <span class="hlt">transport</span> processes has received increasing attention in recent years, attention related to concerns about water clarity, pollutant distribution and <span class="hlt">transport</span>, dredge spoil disposal, creation and maintenance of channels and basins for navigational purposes, and shoreline erosion. Still, the geophysical community that addresses these concerns and the underlying fundamentals of <span class="hlt">sediment</span> <span class="hlt">transport</span> in an estuary is widely but relatively sparsely distributed around the world. The need to draw these researchers together to discuss ideas and outlooks led to the AGU Chapman Conference on <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Processes in Estuaries that was held at the Universidad Nacional del Sur in Bahía Bianca, Argentina, from June 13 to June 17, 1988 [Perillo and Lavelle, 1988]. The meeting sought to provide a timely impetus to further progress in <span class="hlt">sediment</span> <span class="hlt">transport</span> research in estuaries, promote communication among researchers using different investigatory approaches, and develop collaborations among estuarine scientists in developed and developing nations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMEP22A..06F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMEP22A..06F"><span>Size segregation in bedload <span class="hlt">sediment</span> <span class="hlt">transport</span> at the particle scale</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Frey, P.; Martin, T.</p> <p>2011-12-01</p> <p>Bedload, the larger material that is <span class="hlt">transported</span> in stream channels, has major consequences, for the management of water resources, for environmental sustainability, and for flooding alleviation. Most particularly, in mountains, steep slopes drive intense <span class="hlt">transport</span> of a wide range of grain sizes. Our ability to compute local and even bulk quantities such as the <span class="hlt">sediment</span> flux in rivers is poor. One important reason is that grain-grain interactions in stream channels may have been neglected. An arguably most important difficulty pertains to the very wide range of grain size leading to grain size sorting or segregation. This phenomenon largely modifies fluxes and results in patterns that can be seen ubiquitously in nature such as armoring or downstream fining. Most studies have concerned the spontaneous percolation of fine grains into immobile gravels, because of implications for salmonid spawning beds, or stratigraphical interpretation. However when the substrate is moving, the segregation process is different as statistically void openings permit downward percolation of larger particles. This process also named "kinetic sieving" has been studied in industrial contexts where segregation of granular or powder materials is often non-desirable. We present an experimental study of two-size mixtures of coarse spherical glass beads entrained by a shallow turbulent and supercritical water flow down a steep channel with a mobile bed. The particle diameters were 4 and 6mm, the channel width 6.5mm and the channel inclination ranged from 7.5 to 12.5%. The water flow rate and the particle rate were kept constant at the upstream entrance. First only the coarser particle rate was input and adjusted to obtain <span class="hlt">bed</span> <span class="hlt">load</span> equilibrium, that is, neither bed degradation nor aggradation over sufficiently long time intervals. Then a low rate of smaller particles (about 1% of the total <span class="hlt">sediment</span> rate) was introduced to study the spatial and temporal evolution of segregating smaller particles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wsp/1476/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wsp/1476/report.pdf"><span>Investigations of <span class="hlt">Sediment</span> <span class="hlt">Transportation</span>, Middle Loup River at Dunning, Nebraska: With Application of Data from Turbulence Flume</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hubbell, David Wellington; Matejka, Donald Quintin</p> <p>1959-01-01</p> <p> information includes <span class="hlt">sediment</span> discharges; particle-size analyses of total load, of measured suspended <span class="hlt">sediment</span>, and of bed material; water discharges and other hydraulic data for the turbulence flume and the selected sections. <span class="hlt">Sediment</span> discharges have been computed with several different formulas, and insofar as possible, each computed load has been compared with data from the turbulence flume. <span class="hlt">Sediment</span> discharges computed with the Einstein procedure did not agree well, in general, with comparable measured loads. However, a satisfactory representative cross section for the reach could not be determined with the cross sections that were selected for this investigation. If the computed cross section was narrower and deeper than a representative cross section for the reach, computed loads were high; and if the computed cross section was wider and shallower than a representative cross section for the reach, computed loads were low. Total <span class="hlt">sediment</span> discharges computed with the modified Einstein procedure compared very well with the loads of individual size ranges and the measured total loads at the turbulence flume. <span class="hlt">Sediment</span> discharges computed with the Straub equation averaged about twice the measured total <span class="hlt">sediment</span> discharge at the turbulence flume. <span class="hlt">Bed-load</span> discharges computed with the Kalinske equation were of about the right magnitude; however, high computed loads were associated with low total loads, low unmeasured loads, and low concentrations of measured suspended <span class="hlt">sediment</span> coarser than 0.125 millimeter. <span class="hlt">Bed-load</span> discharges computed with the Schoklitsch equation seemed somewhat high; about one-third of the computed loads were slightly higher than comparable unmeasured loads. Although, in general, high computed discharges with the Schoklitsch equation were associated with high measured total loads, high unmeasured loads, and high concentrations of measured suspended <span class="hlt">sediment</span> coarser than 0.125 millimeter, the trend was not consistent. <span class="hlt">Bed-load</span> discharges computed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ESRv..112..115K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ESRv..112..115K"><span>Earth's portfolio of extreme <span class="hlt">sediment</span> <span class="hlt">transport</span> events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korup, Oliver</p> <p>2012-05-01</p> <p>Quantitative estimates of <span class="hlt">sediment</span> flux and the global cycling of <span class="hlt">sediments</span> from hillslopes to rivers, estuaries, deltas, continental shelves, and deep-sea basins have a long research tradition. In this context, extremely large and commensurately rare <span class="hlt">sediment</span> <span class="hlt">transport</span> events have so far eluded a systematic analysis. To start filling this knowledge gap I review some of the highest reported <span class="hlt">sediment</span> yields in mountain rivers impacted by volcanic eruptions, earthquake- and storm-triggered landslide episodes, and catastrophic dam breaks. Extreme specific yields, defined here as those exceeding the 95th percentile of compiled data, are ~ 104 t km- 2 yr- 1 if averaged over 1 yr. These extreme yields vary by eight orders of magnitude, but systematically decay with reference intervals from minutes to millennia such that yields vary by three orders of magnitude for a given reference interval. <span class="hlt">Sediment</span> delivery from natural dam breaks and pyroclastic eruptions dominate these yields for a given reference interval. Even if averaged over 102-103 yr, the contribution of individual disturbances may remain elevated above corresponding catchment denudation rates. I further estimate rates of <span class="hlt">sediment</span> (re-)mobilisation by individual giant terrestrial and submarine mass movements. Less than 50 postglacial submarine mass movements have involved an equivalent of ~ 10% of the contemporary annual global flux of fluvial <span class="hlt">sediment</span> to Earth's oceans, while mobilisation rates by individual events rival the decadal-scale <span class="hlt">sediment</span> discharge from tectonically active orogens such as Taiwan or New Zealand. <span class="hlt">Sediment</span> flushing associated with catastrophic natural dam breaks is non-stationary and shows a distinct kink at the last glacial-interglacial transition, owing to the drainage of very large late Pleistocene ice-marginal lakes. Besides emphasising the contribution of high-magnitude and low-frequency events to the global <span class="hlt">sediment</span> cascade, these findings stress the importance of <span class="hlt">sediment</span> storage</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1376...45C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1376...45C"><span>Multiscale <span class="hlt">Sediment</span>-Laden Flow Theory and Its Application in Flood Risk Management</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Z. X.; Pender, G.; Hu, P.</p> <p>2011-09-01</p> <p><span class="hlt">Sediment</span>-laden flows over erodible bed normally feature multiple time scales. The time scales of <span class="hlt">sediment</span> <span class="hlt">transport</span> and bed deformation relative to the flow essentially measure how fast <span class="hlt">sediment</span> <span class="hlt">transport</span> adapts to capacity regime in line with local flow scenario and the bed deforms as compared to the flow, which literally dictate if a capacity based and/or decoupled model is justified. This paper synthesizes the recently developed multiscale theory for <span class="hlt">sediment</span>-laden flows over erodible bed, with <span class="hlt">bed</span> <span class="hlt">load</span> and suspended load <span class="hlt">transport</span> respectively. It is unravelled that <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> can adapt to capacity sufficiently rapidly even under highly unsteady flows and thus a capacity model is mostly applicable, whereas a non-capacity model is critical for suspended <span class="hlt">sediment</span> because of the lower rate of adaptation to capacity. Physically coupled modeling is critical for cases characterized by rapid bed variation. Applications are outlined on flash floods and landslide dam break floods.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP41B1837H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP41B1837H"><span>Incision of the Jezero Crater Outflow Channel by Fluvial <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holo, S.; Kite, E. S.</p> <p>2017-12-01</p> <p>Jezero crater, the top candidate landing site for the Mars 2020 rover, once possessed a lake that over-spilled and eroded a large outflow channel into the Eastern rim. The Western deltaic <span class="hlt">sediments</span> that would be the primary science target of the rover record a history of lake level, which is modulated by the inflow and outflow channels. While formative discharges for the Western delta exist ( 500 m3/s), little work has been done to see if these flows are the same responsible for outflow channel incision. Other models of the Jezero outflow channel incision assume that a single rapid flood (incision timescales of weeks), with unknown initial hydraulic head and no discharge into the lake (e.g. from the inflow channels or the subsurface), incised an open channel with discharge modulated by flow over a weir. We present an alternate model where, due to an instability at the threshold of <span class="hlt">sediment</span> motion, the incision of the outflow channel occurs in concert with lake filling. In particular, we assume a simplified lake-channel-valley system geometry and that the channel is hydraulically connected to the filling/draining crater lake. <span class="hlt">Bed</span> <span class="hlt">load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> and water discharge through the channel are quantified using the Meyer-Peter and Mueller relation and Manning's law respectively. Mass is conserved for both water and <span class="hlt">sediment</span> as the lake level rises/falls and the channel incises. This model does not resolve backwater effects or concavity in the alluvial system, but it does capture the non-linear feedbacks between lake draining, erosion rate, channel flow rate, and slope relaxation. We identify controls on incision of the outflow channel and estimate the time scale of outflow channel formation through a simple dynamical model. We find that the observed 300m of channel erosion can be reproduced in decades to centuries of progressive <span class="hlt">bed</span> <span class="hlt">load</span> as the delta forming flows fill the lake. This corresponds to time scales on the order of or smaller than the time scale</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA236240','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA236240"><span>Modelling of Nearshore <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1990-03-01</p> <p>dimensional, consisting of the vertical motion of a layer of sand, as modeled for example by Fredsoe, Andersen, and Silberg (1985). The scales of the...Andersen. and S. Silberg . 1985. Distribution of suspended <span class="hlt">sediment</span> in large waves. J. Waterwav. Port Coastal. Ocean Div., 111 (6). 1041-1059. Gillie. R. D</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15306426','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15306426"><span>Modelling sheet-flow <span class="hlt">sediment</span> <span class="hlt">transport</span> in wave-bottom boundary layers using discrete-element modelling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Calantoni, Joseph; Holland, K Todd; Drake, Thomas G</p> <p>2004-09-15</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> in oscillatory boundary layers is a process that drives coastal geomorphological change. Most formulae for <span class="hlt">bed-load</span> <span class="hlt">transport</span> in nearshore regions subsume the smallest-scale physics of the phenomena by parametrizing interactions amongst particles. In contrast, we directly simulate granular physics in the wave-bottom boundary layer using a discrete-element model comprised of a three-dimensional particle phase coupled to a one-dimensional fluid phase via Newton's third law through forces of buoyancy, drag and added mass. The particulate <span class="hlt">sediment</span> phase is modelled using discrete particles formed to approximate natural grains by overlapping two spheres. Both the size of each sphere and the degree of overlap can be varied for these composite particles to generate a range of non-spherical grains. Simulations of particles having a range of shapes showed that the critical angle--the angle at which a grain pile will fail when tilted slowly from rest--increases from approximately 26 degrees for spherical particles to nearly 39 degrees for highly non-spherical composite particles having a dumbbell shape. Simulations of oscillatory sheet flow were conducted using composite particles with an angle of repose of approximately 33 degrees and a Corey shape factor greater than about 0.8, similar to the properties of beach sand. The results from the sheet-flow simulations with composite particles agreed more closely with laboratory measurements than similar simulations conducted using spherical particles. The findings suggest that particle shape may be an important factor for determining <span class="hlt">bed-load</span> flux, particularly for larger bed slopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..277D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..277D"><span>Prediction of bedload <span class="hlt">sediment</span> <span class="hlt">transport</span> for heterogeneous <span class="hlt">sediments</span> in shape</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Durafour, Marine; Jarno, Armelle; Le Bot, Sophie; Lafite, Robert; Marin, François</p> <p>2015-04-01</p> <p>Key words: Particle shape, in-situ measurements, bedload <span class="hlt">transport</span>, heterogeneous <span class="hlt">sediments</span> Bedload <span class="hlt">sediment</span> <span class="hlt">transport</span> in the coastal area is a dynamic process mainly influenced by the type of hydrodynamic forcings involved (current and/or waves), the flow properties (velocity, viscosity, depth) and <span class="hlt">sediment</span> heterogeneity (particle size, density, shape). Although particle shape is recognized to be a significant factor in the hydrodynamic behavior of grains, this parameter is not currently implemented in bedload <span class="hlt">transport</span> formulations: firstly because the mechanisms of initiation of motion according to particle shape are still not fully understood, and secondly due to the difficulties in defining common shape parameters. In March 2011, a large panel of in-situ instruments was deployed on two sites in the Eastern English Channel, during the sea campaign MESFLUX11. Samples of the <span class="hlt">sediment</span> cover available for <span class="hlt">transport</span> are collected, during a slack period, per 2cm thick strata by divers and by using a Shipeck grab. Bedload discharges along a tidal cycle are also collected with a Delft Nile Sampler (DNS; Gaweesh and Van Rijn, 1992, 1994) on both sites. The first one is characterized by a sandy bed with a low size dispersion, while the other study area implies graded <span class="hlt">sediments</span> from fine sands to granules. A detailed analysis of the data is performed to follow the evolution of in-situ bedload fluxes on the seabed for a single current. In-situ measurements are compared to existing formulations according to a single fraction approach, using the median diameter of the mixture, and a fractionwise approach, involving a discretization of the grading curve. Results emphasize the interest to oscillate between these two methods according to the dispersion in size of the site considered. The need to apply a hiding/exposure coefficient (Egiazaroff, 1965) and a hindrance factor (Kleinhans and Van Rijn, 2002) for size heterogeneous <span class="hlt">sediments</span> is also clearly highlighted. A really good</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.epa.gov/clinton-river-aoc/clinton-river-sediment-transport-modeling-study','PESTICIDES'); return false;" href="https://www.epa.gov/clinton-river-aoc/clinton-river-sediment-transport-modeling-study"><span>Clinton River <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Modeling Study</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>The U.S. ACE develops <span class="hlt">sediment</span> <span class="hlt">transport</span> models for tributaries to the Great Lakes that discharge to AOCs. The models developed help State and local agencies to evaluate better ways for soil conservation and non-point source pollution prevention.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=water+AND+hydraulics&pg=2&id=EJ288687','ERIC'); return false;" href="https://eric.ed.gov/?q=water+AND+hydraulics&pg=2&id=EJ288687"><span>A Field Exercise in Fluvial <span class="hlt">Sediment</span> <span class="hlt">Transport</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tharp, Thomas M.</p> <p>1983-01-01</p> <p>Describes an investigation which introduces the mathematical principles of stream hydraulics and fluvial <span class="hlt">sediment</span> in a practical context. The investigation has four stages: defining hydrology of the stream; defining channel hydraulics in a study reach; measuring grain size; and calculating <span class="hlt">transportable</span> grain size and comparing measure stream-bed…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7856','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7856"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span>-storage relations for degrading, gravel bed channels</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas E. Lisle; Michael Church</p> <p>2002-01-01</p> <p>In a drainage network,<span class="hlt">sediment</span> is transferred through a series of channel/valley segments (natural <span class="hlt">sediment</span> storage reservoirs) that are distinguished from their neighbors by their particular capacity to store and <span class="hlt">transport</span> <span class="hlt">sediment</span>. We propose that the <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity of each reservoir is a unique positive function of storage volume, which influences...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7866','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7866"><span>Variability of bed mobility in natural, gravel-bed channels and adjustments to <span class="hlt">sediment</span> load at local and reach scales</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas E. Lisle; Jonathan M. Nelson; John Pitlick; Mary Ann Madej; Brent L. Barkett</p> <p>2000-01-01</p> <p>Abstract - Local variations in boundary shear stress acting on bed-surface particles control patterns of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> and channel evolution during varying stream discharges. At the reach scale a channel adjusts to imposed water and <span class="hlt">sediment</span> supply through mutual interactions among channel form, local grain size, and local flow dynamics that govern bed mobility...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711736R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711736R"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> monitoring for sustainable hydropower development</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rüther, Nils; Guerrero, Massimo; Stokseth, Siri</p> <p>2015-04-01</p> <p>Due to the increasing demand of CO2 neutral energy not only in Europe but also in World, a relatively large amount of new hydro power plants (HPP) are built. In addition, will existing ones refurbished and renewed in order to run them more cost effective. A huge thread to HPPs is incoming <span class="hlt">sediments</span> in suspension from the rivers upstream. The <span class="hlt">sediments</span> settle in the reservoir and reduce the effective head and volume and reduce consequently the life time of the reservoir. In addition are the fine <span class="hlt">sediments</span> causing severe damages to turbines and infrastructure of a HPP. For estimating the amount of incoming <span class="hlt">sediments</span> in suspension and therefore planning efficient counter measures, it is essential to monitor the rivers within the catchment of the HPP for suspended <span class="hlt">sediments</span>. This work is considerably time consuming and requires highly educated personnel and is therefore expensive. Consequently will this study present a method to measure suspended <span class="hlt">sediment</span> concentrations and their grain size distribution with a dual frequency acoustic Doppler current profiler (ADCP). This method is more cost effective and reliable in comparison to traditional measurement methods. Having more detailed information about the <span class="hlt">sediments</span> being <span class="hlt">transported</span> in a river, the hydro power plant can be planned, built, and operated much more efficiently and sustainable. The two horizontal ADCPs are installed at a measurement cross section in the Devoll river in Albania. To verify the new method, the suspended load concentrations will be monitored also in the traditional ways at the same cross sections. It is planned to install turbidity measurement devices included with an automatic sampling devices. It is also planned to use an optical in situ measurement device (LISST SL by Sequoia Inc.) to have detailed information of <span class="hlt">sediment</span> concentration and grain sizes over the depth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612529P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612529P"><span>The <span class="hlt">sediments</span> <span class="hlt">transport</span> outcome from granite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petre, Maria</p> <p>2014-05-01</p> <p>A landscape can be characterized by natural elements but also by the activity of the people. The shape of the landscape depends on the nature's type of rocks which compose the subsoil and on their physical-chemical properties. The action of the atmospheric factors and the presence of the water at the surface of the Earth can also shape or reshape a landscape and create new elements of the landscape. The rocks who are shaped by natural agents like the water are transformed into small particles or <span class="hlt">sediments</span>. After this process, they can be <span class="hlt">transported</span> by the rivers and deposed in different spots on the river according to the size of the <span class="hlt">sediments</span>. For instance, the sand and the gravels do not travel on the same distances. The sand can be <span class="hlt">transported</span> on a long distance and deposed near the oceans or seas, while the gravels are not <span class="hlt">transported</span> to far from the source area. Once the <span class="hlt">sediments</span> are no longer <span class="hlt">transported</span> by the water, they are forming sedimentary deposits and. The sedimentary deposits suffer some transformations: a compaction and a cementation which will form the sedimentary rocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28733603','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28733603"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> drives tidewater glacier periodicity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brinkerhoff, Douglas; Truffer, Martin; Aschwanden, Andy</p> <p>2017-07-21</p> <p>Most of Earth's glaciers are retreating, but some tidewater glaciers are advancing despite increasing temperatures and contrary to their neighbors. This can be explained by the coupling of ice and <span class="hlt">sediment</span> dynamics: a shoal forms at the glacier terminus, reducing ice discharge and causing advance towards an unstable configuration followed by abrupt retreat, in a process known as the tidewater glacier cycle. Here we use a numerical model calibrated with observations to show that interactions between ice flow, glacial erosion, and <span class="hlt">sediment</span> <span class="hlt">transport</span> drive these cycles, which occur independent of climate variations. Water availability controls cycle period and amplitude, and enhanced melt from future warming could trigger advance even in glaciers that are steady or retreating, complicating interpretations of glacier response to climate change. The resulting shifts in <span class="hlt">sediment</span> and meltwater delivery from changes in glacier configuration may impact interpretations of marine <span class="hlt">sediments</span>, fjord geochemistry, and marine ecosystems.The reason some of the Earth's tidewater glaciers are advancing despite increasing temperatures is not entirely clear. Here, using a numerical model that simulates both ice and <span class="hlt">sediment</span> dynamics, the authors show that internal dynamics drive glacier variability independent of climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70120867','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70120867"><span>Continental margin <span class="hlt">sedimentation</span>: From <span class="hlt">sediment</span> <span class="hlt">transport</span> to sequence stratigraphy</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P. M.; Wiberg, Patricia L.</p> <p>2007-01-01</p> <p>This volume on continental margin <span class="hlt">sedimentation</span> brings together an expert editorial and contributor team to create a state-of-the-art resource. Taking a global perspective, the book spans a range of timescales and content, ranging from how oceans <span class="hlt">transport</span> particles, to how thick rock sequences are formed on continental margins.- Summarizes and integrates our understanding of sedimentary processes and strata associated with fluvial dispersal systems on continental shelves and slopes- Explores timescales ranging from particle <span class="hlt">transport</span> at one extreme, to deep burial at the other- Insights are presented for margins in general, and with focus on a tectonically active margin (northern California) and a passive margin (New Jersey), enabling detailed examination of the intricate relationships between a wide suite of sedimentary processes and their preserved stratigraphy- Includes observational studies which document the processes and strata found on particular margins, in addition to numerical models and laboratory experimentation, which provide a quantitative basis for extrapolation in time and space of insights about continental-margin <span class="hlt">sedimentation</span>- Provides a research resource for scientists studying modern and ancient margins, and an educational text for advanced students in sedimentology and stratigraphy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70012433','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70012433"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> in Norton Sound, Alaska</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Drake, D.E.; Cacchione, D.A.; Muench, R.D.; Nelson, C.H.</p> <p>1980-01-01</p> <p>The Yukon River, the largest single source of Bering Sea <span class="hlt">sediment</span>, delivers >95% of its <span class="hlt">sediment</span> load at the southwest corner of Norton Sound during the ice-free months of late May through October. During this period, surface winds in the northern Bering Sea area are generally light from the south and southwest, and surface waves are not significant. Although wind stress may cause some <span class="hlt">transport</span> of low-density turbid surface water into the head of Norton Sound, the most significant <span class="hlt">transport</span> of Yukon River suspended matter occurs within advective currents flowing north across the outer part of the sound. The thickest accumulations of modern Yukon silt and very fine sand occur beneath this persistent current. We monitored temporal variations in bottom currents, pressure, and suspended-matter concentrations within this major <span class="hlt">transport</span> pathway for 80 days in the summer of 1977 using a Geological Processes Bottom Environmental (GEOPROBE) tripod system. The record reveals two distinctive periods of bottom flow and <span class="hlt">sediment</span> <span class="hlt">transport</span>: an initial 59 days (July 8-September 5) of fair-weather conditions, characterized by tidally dominated currents and relatively low, stable suspended-matter concentrations; and a 21-day period (September 5-September 26) during which several storms traversed the northern Bering Sea, mean suspended-matter concentrations near the bottom increased by a factor of five, and the earlier tidal dominance was overshadowed by wind-driven and oscillatory wave-generated currents. Friction velocities (u*) at the GEOPROBE site were generally subcritical during the initial fair-weather period. In contrast, the 21-day stormy period was characterized by u* values that exceeded the critical level of 1.3 cm/s more than 60% of the time. The GEPROBE data suggest that the very fine sand constituting about 50% of the <span class="hlt">sediment</span> on the outer part of the Yukon prodelta is <span class="hlt">transported</span> during a few late-summer and fall storms each year. A conservative estimate shows that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA604359','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA604359"><span>Regional <span class="hlt">Sediment</span> Management (RSM) Modeling Tools: Integration of Advanced <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Tools into HEC-RAS</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-06-01</p> <p>Integration of Advanced <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Tools into HEC-RAS by Paul M. Boyd and Stanford A. Gibson PURPOSE: This Coastal and Hydraulics Engineering...Technical Note (CHETN) summarizes the development and initial testing of new <span class="hlt">sediment</span> <span class="hlt">transport</span> and modeling tools developed by the U.S. Army Corps...<span class="hlt">sediment</span> <span class="hlt">transport</span> within the USACE HEC River Analysis System (HEC-RAS) software package and to determine its applicability to Regional <span class="hlt">Sediment</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7855','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7855"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span>-storage functions for alluvial reservoirs</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas E. Lisle; Michael Church</p> <p>2000-01-01</p> <p>In a drainage network, <span class="hlt">sediment</span> is routed through a linked series of channel/valley segments (alluvial reservoirs) that are distinguished from their neighbors by their capacity to store and <span class="hlt">transport</span> <span class="hlt">sediment</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=56121&Lab=NERL&keyword=phytoremediation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=56121&Lab=NERL&keyword=phytoremediation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>WATERSHED AND INSTREAM MODELING OF <span class="hlt">SEDIMENT</span> FATE AND <span class="hlt">TRANSPORT</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>To effectively manage watersheds, the assessment of watershed ecological response to physicochemical stressors such as <span class="hlt">sediments</span> over broad spatial and temporal scales is needed. Assessments at this level of complexity requires the development of <span class="hlt">sediment</span> <span class="hlt">transport</span> and fate model...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212181L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212181L"><span>Numerical modelling of bedload <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langlois, Vincent J.</p> <p>2010-05-01</p> <p>We present a numerical study of <span class="hlt">sediment</span> <span class="hlt">transport</span> in the bedload regime. Classical bedload <span class="hlt">transport</span> laws only describe the variation of the vertically integrated flux of grains as a function of the Shields number. However, these relations are only valid if the moving layer of the bed is at equilibrium with the external flow. Besides, they do not contain enough information for many geomorphological applications. For instance, understanding inertial effects in the moving bed requires models that are able to account for the variability of hydrodynamical conditions, and the discrete nature of the <span class="hlt">sediment</span> material. We developped a numerical modelling of the behaviour of a three-dimensional bed of grains sheared by a unidirectional fluid flow. These simulations are based on a combination of discrete and continuum approaches: <span class="hlt">sediment</span> particles are modelled by hard spheres interacting through simple contact forces, whereas the fluid flow is described by a 'mean field' model. Both the drag exerted on grains by the fluid and the retroactive effect of the presence of grains on the flow are accounted for, allowing the system to converge to its equilibrium state (no assumption is made on the fluid velocity profile inside the layer of moving grains). Above the motion threshold, the variation of the flux of grains in the steady state is found to vary like the cube of the Shields number (as predicted by Bagnold). Besides, our simulations allow us to obtain new insights into the detailed mechanisms of bedload <span class="hlt">transport</span>, by giving access to non-integral quantities, such as the trajectories of each individual grains, the detailed velocity and packing fraction profiles inside the granular bed, etc. It is therefore possible to investigate some effects that are not accounted for in usual continuum models, such as the polydispersity of grains, the ageing of the bed, the response to a variation of the flowrate, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988Natur.331..518G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988Natur.331..518G"><span>A deep-sea <span class="hlt">sediment</span> <span class="hlt">transport</span> storm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gross, Thomas F.; Williams, A. J.; Newell, A. R. M.</p> <p>1988-02-01</p> <p>Photographs taken of the sea bottom since the 1960s suggest that <span class="hlt">sediments</span> at great depth may be actively resuspended and redistributed1. Further, it has been suspected that active resus-pension/<span class="hlt">transport</span> may be required to maintain elevated concentrations of particles in deep-sea nepheloid layers. But currents with sufficient energy to erode the bottom, and to maintain the particles in suspension, have not been observed concurrently with large concentrations of particles in the deep nepheloid layer2-4. The high-energy benthic boundary-layer experiment (HEBBLE) was designed to test the hypothesis that bed modifications can result from local erosion and deposition as modelled by simple one-dimensional local forcing mechanics5. We observed several 'storms' of high kinetic energy and near-bed flow associated with large concentrations of suspended <span class="hlt">sediment</span> during the year-long deployments of moored instruments at the HEBBLE study site. These observations, at 4,880 m off the Nova Scotian Rise in the north-west Atlantic, indicate that large episodic events may suspend bottom <span class="hlt">sediments</span> in areas well removed from coastal and shelf sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2951S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2951S"><span>Soil aggregate stability and rainfall-induced <span class="hlt">sediment</span> <span class="hlt">transport</span> on field plots as affected by amendment with organic matter inputs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Pu; Arter, Christian; Liu, Xingyu; Keller, Martin; Schulin, Rainer</p> <p>2017-04-01</p> <p> end of the rainfall events due to emerging <span class="hlt">bed-load</span> <span class="hlt">transport</span>. The results show that a single application of organic matter can already cause a large difference in aggregate breakdown, surface sealing, and lateral <span class="hlt">sediment</span>-associated matter transfer under rainfall impact. Furthermore, we will present terrestrial laser scanning data showing the treatment effects on soil surface structure, as well as data on carbon, phosphorus and heavy metal export associated with the translocation of the <span class="hlt">sediments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.S43A2793F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.S43A2793F"><span>Monitoring the <span class="hlt">Transport</span> of <span class="hlt">Sediment</span> During Tropical Cyclones From High-frequency Seismic Noise in Two Rivers of La Réunion Island</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fontaine, F. R.; Gonzalez, A.; Burtin, A.; Barruol, G.; Recking, A.; Join, J. L.; Delcher, E.</p> <p>2016-12-01</p> <p>La Réunion Island is a basaltic shield volcano located in the western Indian Ocean. The island undergoes heavy annual precipitations during tropical depressions and cyclones. These rainfalls modify the stream dynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> of rivers. The <span class="hlt">transport</span> of <span class="hlt">sediment</span> participates to the erosion of the volcanic island, however, in situ characterization is difficult during high water stage. In the frame of the Rivière des Pluies project, we are deploying a temporary seismic network of 10 three-component broadband seismometers around two rivers: Rivière des Pluies and Rivière du Mât. The goal of the project is to monitor spatial and temporal variations of the river's <span class="hlt">bed-load</span> during tropical cyclones with high-frequency noise. Meteorological and hydrological stations are installed at both rivers providing valuable data such as precipitations, water discharge and water level. We will also sample the bed surface grain size distribution by visual count to determine its influence on the seismic noise. We present preliminary results from two broadband seismic stations located near instrumented streams. SALA station from the temporary RHUM-RUM seismic network (http://www.rhum-rum.net/en/) was installed close to the Rivière du Mât and the permanent GEOSCOPE RER station is located close to the Rivière de l'Est. We analyzed the footprint of the cyclone Bejisa in January 2014. We observe a significant increase of the precipitation when the cyclone eye is 300 km close to the island followed by the increase of the water discharge. Simultaneously the seismic signal shows a sudden increase of the power spectral density visible above 1 Hz. Further investigations on the relationship between the seismic noise and the hydrological and meteorological parameters will help us quantifying the river <span class="hlt">bed-load</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031826','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031826"><span>Storm-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> in Massachusetts Bay</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Warner, J.C.; Butman, B.; Dalyander, P.S.</p> <p>2008-01-01</p> <p>Massachusetts Bay is a semi-enclosed embayment in the western Gulf of Maine about 50 km wide and 100 km long. Bottom <span class="hlt">sediment</span> resuspension is controlled predominately by storm-induced surface waves and <span class="hlt">transport</span> by the tidal- and wind-driven circulation. Because the Bay is open to the northeast, winds from the northeast ('Northeasters') generate the largest surface waves and are thus the most effective in resuspending <span class="hlt">sediments</span>. The three-dimensional oceanographic circulation model Regional Ocean Modeling System (ROMS) is used to explore the resuspension, <span class="hlt">transport</span>, and deposition of <span class="hlt">sediment</span> caused by Northeasters. The model <span class="hlt">transports</span> multiple <span class="hlt">sediment</span> classes and tracks the evolution of a multilevel <span class="hlt">sediment</span> bed. The surficial <span class="hlt">sediment</span> characteristics of the bed are coupled to one of several bottom-boundary layer modules that calculate enhanced bottom roughness due to wave-current interaction. The wave field is calculated from the model Simulating WAves Nearshore (SWAN). Two idealized simulations were carried out to explore the effects of Northeasters on the <span class="hlt">transport</span> and fate of <span class="hlt">sediments</span>. In one simulation, an initially spatially uniform bed of mixed <span class="hlt">sediments</span> exposed to a series of Northeasters evolved to a pattern similar to the existing surficial <span class="hlt">sediment</span> distribution. A second set of simulations explored <span class="hlt">sediment-transport</span> pathways caused by storms with winds from the northeast quadrant by simulating release of <span class="hlt">sediment</span> at selected locations. Storms with winds from the north cause <span class="hlt">transport</span> southward along the western shore of Massachusetts Bay, while storms with winds from the east and southeast drive northerly nearshore flow. The simulations show that Northeasters can effectively <span class="hlt">transport</span> <span class="hlt">sediments</span> from Boston Harbor and the area offshore of the harbor to the southeast into Cape Cod Bay and offshore into Stellwagen Basin. This <span class="hlt">transport</span> pattern is consistent with Boston Harbor as the source of silver found in the surficial <span class="hlt">sediments</span> of Cape Cod Bay and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713082V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713082V"><span>"Smart pebble" designs for <span class="hlt">sediment</span> <span class="hlt">transport</span> monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valyrakis, Manousos; Alexakis, Athanasios; Pavlovskis, Edgars</p> <p>2015-04-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span>, due to primarily the action of water, wind and ice, is one of the most significant geomorphic processes responsible for shaping Earth's surface. It involves entrainment of <span class="hlt">sediment</span> grains in rivers and estuaries due to the violently fluctuating hydrodynamic forces near the bed. Here an instrumented particle, namely a "smart pebble", is developed to investigate the exact flow conditions under which individual grains may be entrained from the surface of a gravel bed. This could lead in developing a better understanding of the processes involved, focusing on the response of the particle during a variety of flow entrainment events. The "smart pebble" is a particle instrumented with MEMS sensors appropriate for capturing the hydrodynamic forces a coarse particle might experience during its entrainment from the river bed. A 3-axial gyroscope and accelerometer registers data to a memory card via a microcontroller, embedded in a 3D-printed waterproof hollow spherical particle. The instrumented board is appropriately fit and centred into the shell of the pebble, so as to achieve a nearly uniform distribution of the mass which could otherwise bias its motion. The "smart pebble" is powered by an independent power to ensure autonomy and sufficiently long periods of operation appropriate for deployment in the field. Post-processing and analysis of the acquired data is currently performed offline, using scientific programming software. The performance of the instrumented particle is validated, conducting a series of calibration experiments under well-controlled laboratory conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JGRF..114.4023A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JGRF..114.4023A"><span>Pebble abrasion during fluvial <span class="hlt">transport</span>: Experimental results and implications for the evolution of the <span class="hlt">sediment</span> load along rivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Attal, Mikaël; Lavé, Jérôme</p> <p>2009-12-01</p> <p>In actively eroding landscapes, fluvial abrasion modifies the characteristics of the <span class="hlt">sediment</span> carried by rivers and consequently has a direct impact on the ability of mountain rivers to erode their bedrock and on the characteristics and volume of the <span class="hlt">sediment</span> exported from upland catchments. In this experimental study, we use a novel flume replicating hydrodynamic conditions prevailing in mountain rivers to investigate the role played by different controlling variables on pebble abrasion during fluvial <span class="hlt">transport</span>. Lithology controls abrasion rates and processes, with differences in abrasion rates exceeding two orders of magnitude. Attrition as well as breaking and splitting are efficient processes in reducing particle size. Mass loss by attrition increases with particle velocity but is weakly dependent on particle size. Fragment production is enhanced by the use of large particles, high impact velocities and the presence of joints. Based on our experimental results, we extrapolate a preliminary generic relationship between pebble attrition rate and <span class="hlt">transport</span> stage (τ*/τ*c), where τ* = fluvial Shields stress and τ*c = critical Shields stress for incipient pebble motion. This relationship predicts that attrition rates are independent of <span class="hlt">transport</span> stage for (τ*/τ*c) ≤ 3 and increase linearly with <span class="hlt">transport</span> stage beyond this value. We evaluate the extent to which abrasion rates control downstream fining in several different natural settings. A simplified model predicts that the most resistant lithologies control <span class="hlt">bed</span> <span class="hlt">load</span> flux and fining ratio and that the concavity of <span class="hlt">transport</span>-limited river profiles should rarely exceed 0.25 in the absence of deposition and sorting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=62428&keyword=ensemble&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=62428&keyword=ensemble&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>MODELLING <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> FOR THE LAKE MICHIGAN MASS BALANCE PROJECT</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A <span class="hlt">sediment</span> <span class="hlt">transport</span> model is one component of the overall ensemble of models being developed for the Lake Michigan Mass Balance. The SEDZL model is being applied to simulate the fine-grained <span class="hlt">sediment</span> <span class="hlt">transport</span> in Lake Michigan for the 1982-1983 and 1994-1995 periods. Model perf...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP51B0911O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP51B0911O"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Over Run-of-River Dams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>O'Brien, M.; Magilligan, F. J.; Renshaw, C. E.</p> <p>2016-12-01</p> <p>Dams have numerous documented effects that can degrade river habitat downstream. One significant effect of large dams is their ability to trap <span class="hlt">sediment</span> delivered from upstream. This trapping can alter <span class="hlt">sediment</span> <span class="hlt">transport</span> and grain size downstream - effects that often motivate dam removal decisions. However, recent indirect observations and modeling studies indicate that small, run-of-river (ROR) dams, which do not impede discharge, may actually leak <span class="hlt">sediment</span> downstream. However, there are no direct measurements of <span class="hlt">sediment</span> flux over ROR dams. This study investigates flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> over four to six different New England ROR dams over a summer-fall field season. <span class="hlt">Sediment</span> flux was measured using turbidity meters and tracer (RFID) cobbles. <span class="hlt">Sediment</span> <span class="hlt">transport</span> was also monitored through an undammed control site and through a river where two ROR dams were recently removed. These data were used to predict the conditions that contribute to <span class="hlt">sediment</span> <span class="hlt">transport</span> and trapping. Year 1 data show that tracer rocks of up to 61 mm were <span class="hlt">transported</span> over a 3 m ROR dam in peak flows of 84% of bankfull stage. These tracer rocks were <span class="hlt">transported</span> over and 10 m beyond the dam and continue to move downstream. During the same event, comparable suspended <span class="hlt">sediment</span> fluxes of up to 81 g/s were recorded both upstream and downstream of the dam at near-synchronous timestamps. These results demonstrate the potential for <span class="hlt">sediment</span> <span class="hlt">transport</span> through dammed rivers, even in discharge events that do not exceed bankfull. This research elucidates the effects of ROR dams and the controls on <span class="hlt">sediment</span> <span class="hlt">transport</span> and trapping, contributions that may aid in dam management decisions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70184988','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70184988"><span>Probability distributions of <span class="hlt">bed</span> <span class="hlt">load</span> particle velocities, accelerations, hop distances, and travel times informed by Jaynes's principle of maximum entropy</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Furbish, David; Schmeeckle, Mark; Schumer, Rina; Fathel, Siobhan</p> <p>2016-01-01</p> <p>We describe the most likely forms of the probability distributions of <span class="hlt">bed</span> <span class="hlt">load</span> particle velocities, accelerations, hop distances, and travel times, in a manner that formally appeals to inferential statistics while honoring mechanical and kinematic constraints imposed by equilibrium <span class="hlt">transport</span> conditions. The analysis is based on E. Jaynes's elaboration of the implications of the similarity between the Gibbs entropy in statistical mechanics and the Shannon entropy in information theory. By maximizing the information entropy of a distribution subject to known constraints on its moments, our choice of the form of the distribution is unbiased. The analysis suggests that particle velocities and travel times are exponentially distributed and that particle accelerations follow a Laplace distribution with zero mean. Particle hop distances, viewed alone, ought to be distributed exponentially. However, the covariance between hop distances and travel times precludes this result. Instead, the covariance structure suggests that hop distances follow a Weibull distribution. These distributions are consistent with high-resolution measurements obtained from high-speed imaging of <span class="hlt">bed</span> <span class="hlt">load</span> particle motions. The analysis brings us closer to choosing distributions based on our mechanical insight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26286127','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26286127"><span>Rainfall, runoff and <span class="hlt">sediment</span> <span class="hlt">transport</span> in a Mediterranean mountainous catchment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tuset, J; Vericat, D; Batalla, R J</p> <p>2016-01-01</p> <p>The relation between rainfall, runoff, erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> is highly variable in Mediterranean catchments. Their relation can be modified by land use changes and climate oscillations that, ultimately, will control water and <span class="hlt">sediment</span> yields. This paper analyses rainfall, runoff and <span class="hlt">sediment</span> <span class="hlt">transport</span> relations in a meso-scale Mediterranean mountain catchment, the Ribera Salada (NE Iberian Peninsula). A total of 73 floods recorded between November 2005 and November 2008 at the Inglabaga <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Station (114.5 km(2)) have been analysed. Suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> and flow discharge were measured continuously. Rainfall data was obtained by means of direct rain gauges and daily rainfall reconstructions from radar information. Results indicate that the annual <span class="hlt">sediment</span> yield (2.3 t km(-1) y(-1) on average) and the flood-based runoff coefficients (4.1% on average) are low. The Ribera Salada presents a low geomorphological and hydrological activity compared with other Mediterranean mountain catchments. Pearson correlations between rainfall, runoff and <span class="hlt">sediment</span> <span class="hlt">transport</span> variables were obtained. The hydrological response of the catchment is controlled by the base flows. The magnitude of suspended <span class="hlt">sediment</span> concentrations is largely correlated with flood magnitude, while <span class="hlt">sediment</span> load is correlated with the amount of direct runoff. Multivariate analysis shows that total suspended load can be predicted by integrating rainfall and runoff variables. The total direct runoff is the variable with more weight in the equation. Finally, three main hydro-sedimentary phases within the hydrological year are defined in this catchment: (a) Winter, where the catchment produces only water and very little <span class="hlt">sediment</span>; (b) Spring, where the majority of water and <span class="hlt">sediment</span> is produced; and (c) Summer-Autumn, when little runoff is produced but significant amount of <span class="hlt">sediments</span> is exported out of the catchment. Results show as land use and climate change may have an important</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=311249&keyword=homeland%20security&subject=homeland%20security%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=09/14/2011&dateendpublishedpresented=09/14/2016&sortby=pubdateyear','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=311249&keyword=homeland%20security&subject=homeland%20security%20research&showcriteria=2&fed_org_id=111&datebeginpublishedpresented=09/14/2011&dateendpublishedpresented=09/14/2016&sortby=pubdateyear"><span><span class="hlt">Sediment</span> Resuspension and <span class="hlt">Transport</span> in Water Distribution ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Journal article This journal article addresses the question of how likely tank <span class="hlt">sediments</span> are to be resuspended and to drain from the tank, potentially impacting human health. AUsing computational fluid dynamics software, and <span class="hlt">sediment</span> models from the literature, a variety of normal tank operating conditions are assessed to evaluate the likelihood of tank <span class="hlt">sediment</span> resuspension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1309H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1309H"><span>Significance of flow clustering and sequencing on <span class="hlt">sediment</span> <span class="hlt">transport</span>: 1D <span class="hlt">sediment</span> <span class="hlt">transport</span> modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hassan, Kazi; Allen, Deonie; Haynes, Heather</p> <p>2016-04-01</p> <p>This paper considers 1D hydraulic model data on the effect of high flow clusters and sequencing on <span class="hlt">sediment</span> <span class="hlt">transport</span>. Using observed flow gauge data from the River Caldew, England, a novel stochastic modelling approach was developed in order to create alternative 50 year flow sequences. Whilst the observed probability density of gauge data was preserved in all sequences, the order in which those flows occurred was varied using the output from a Hidden Markov Model (HMM) with generalised Pareto distribution (GP). In total, one hundred 50 year synthetic flow series were generated and used as the inflow boundary conditions for individual flow series model runs using the 1D <span class="hlt">sediment</span> <span class="hlt">transport</span> model HEC-RAS. The model routed graded <span class="hlt">sediment</span> through the case study river reach to define the long-term morphological changes. Comparison of individual simulations provided a detailed understanding of the sensitivity of channel capacity to flow sequence. Specifically, each 50 year synthetic flow sequence was analysed using a 3-month, 6-month or 12-month rolling window approach and classified for clusters in peak discharge. As a cluster is described as a temporal grouping of flow events above a specified threshold, the threshold condition used herein is considered as a morphologically active channel forming discharge event. Thus, clusters were identified for peak discharges in excess of 10%, 20%, 50%, 100% and 150% of the 1 year Return Period (RP) event. The window of above-peak flows also required cluster definition and was tested for timeframes 1, 2, 10 and 30 days. Subsequently, clusters could be described in terms of the number of events, maximum peak flow discharge, cumulative flow discharge and skewness (i.e. a description of the flow sequence). The model output for each cluster was analysed for the cumulative flow volume and cumulative <span class="hlt">sediment</span> <span class="hlt">transport</span> (mass). This was then compared to the total <span class="hlt">sediment</span> <span class="hlt">transport</span> of a single flow event of equivalent flow volume</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2228N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2228N"><span>Boulder-Faced Log Dams and other Alternatives for Gabion Check Dams in First-Order Ephemeral Streams with Coarse <span class="hlt">Bed</span> <span class="hlt">Load</span> in Ethiopia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nyssen, Jan; Gebreslassie, Seifu; Assefa, Romha; Deckers, Jozef; Guyassa, Etefa; Poesen, Jean; Frankl, Amaury</p> <p>2017-04-01</p> <p>Many thousands of gabion check dams have been installed to control gully erosion in Ethiopia, but several challenges still remain, such as the issue of gabion failure in ephemeral streams with coarse <span class="hlt">bed</span> <span class="hlt">load</span>, that abrades at the chute step. As an alternative for gabion check dams in torrents with coarse <span class="hlt">bed</span> <span class="hlt">load</span>, boulder-faced log dams were conceived, installed transversally across torrents and tested (n = 30). For this, logs (22-35 cm across) were embedded in the banks of torrents, 0.5-1 m above the bed and their upstream sides were faced with boulders (0.3-0.7 m across). Similar to gabion check dams, boulder-faced log dams lead to temporary ponding, spreading of peak flow over the entire channel width and <span class="hlt">sediment</span> deposition. Results of testing under extreme flow conditions (including two storms with return periods of 5.6 and 7 years) show that 18 dams resisted strong floods. Beyond certain flood thresholds, represented by proxies such as Strahler's stream order, catchment area, D95 or channel width), 11 log dams were completely destroyed. Smallholder farmers see much potential in this type of structure to control first-order torrents with coarse <span class="hlt">bed</span> <span class="hlt">load</span>, since the technique is cost-effective and can be easily installed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29075001','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29075001"><span>Water induced <span class="hlt">sediment</span> levitation enhances downslope <span class="hlt">transport</span> on Mars.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Raack, Jan; Conway, Susan J; Herny, Clémence; Balme, Matthew R; Carpy, Sabrina; Patel, Manish R</p> <p>2017-10-27</p> <p>On Mars, locally warm surface temperatures (~293 K) occur, leading to the possibility of (transient) liquid water on the surface. However, water exposed to the martian atmosphere will boil, and the <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity of such unstable water is not well understood. Here, we present laboratory studies of a newly recognized <span class="hlt">transport</span> mechanism: "levitation" of saturated <span class="hlt">sediment</span> bodies on a cushion of vapor released by boiling. <span class="hlt">Sediment</span> <span class="hlt">transport</span> where this mechanism is active is about nine times greater than without this effect, reducing the amount of water required to <span class="hlt">transport</span> comparable <span class="hlt">sediment</span> volumes by nearly an order of magnitude. Our calculations show that the effect of levitation could persist up to ~48 times longer under reduced martian gravity. <span class="hlt">Sediment</span> levitation must therefore be considered when evaluating the formation of recent and present-day martian mass wasting features, as much less water may be required to form such features than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000EOSTr..81..502S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000EOSTr..81..502S"><span>Workshop discusses community models for coastal <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sherwood, Christopher R.; Signell, Richard P.; Harris, Courtney K.; Butman, Bradford</p> <p></p> <p>Numerical models of coastal <span class="hlt">sediment</span> <span class="hlt">transport</span> are increasingly used to address problems ranging from remediation of contaminated <span class="hlt">sediments</span>, to siting of sewage outfalls and disposal sites, to evaluating impacts of coastal development. They are also used as a test bed for <span class="hlt">sediment-transport</span> algorithms, to provide realistic settings for biological and geochemical models, and for a variety of other research, both fundamental and applied. However, there are few full-featured, publicly available coastal <span class="hlt">sediment-transport</span> models, and fewer still that are well tested and have been widely applied.This was the motivation for a workshop in Woods Hole, Massachusetts, on June 22-23, 2000, that explored the establishment of community models for coastal <span class="hlt">sediment-transport</span> processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70120727','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70120727"><span>Estimating <span class="hlt">sediment</span> discharge: Appendix D</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gray, John R.; Simões, Francisco J. M.</p> <p>2008-01-01</p> <p><span class="hlt">Sediment</span>-discharge measurements usually are available on a discrete or periodic basis. However, estimates of <span class="hlt">sediment</span> <span class="hlt">transport</span> often are needed for unmeasured periods, such as when daily or annual <span class="hlt">sediment</span>-discharge values are sought, or when estimates of <span class="hlt">transport</span> rates for unmeasured or hypothetical flows are required. Selected methods for estimating suspended-<span class="hlt">sediment</span>, <span class="hlt">bed-load</span>, bed- material-load, and total-load discharges have been presented in some detail elsewhere in this volume. The purposes of this contribution are to present some limitations and potential pitfalls associated with obtaining and using the requisite data and equations to estimate <span class="hlt">sediment</span> discharges and to provide guidance for selecting appropriate estimating equations. Records of <span class="hlt">sediment</span> discharge are derived from data collected with sufficient frequency to obtain reliable estimates for the computational interval and period. Most <span class="hlt">sediment</span>- discharge records are computed at daily or annual intervals based on periodically collected data, although some partial records represent discrete or seasonal intervals such as those for flood periods. The method used to calculate <span class="hlt">sediment</span>- discharge records is dependent on the types and frequency of available data. Records for suspended-<span class="hlt">sediment</span> discharge computed by methods described by Porterfield (1972) are most prevalent, in part because measurement protocols and computational techniques are well established and because suspended <span class="hlt">sediment</span> composes the bulk of <span class="hlt">sediment</span> dis- charges for many rivers. Discharge records for <span class="hlt">bed</span> <span class="hlt">load</span>, total load, or in some cases bed-material load plus wash load are less common. Reliable estimation of <span class="hlt">sediment</span> discharges presupposes that the data on which the estimates are based are comparable and reliable. Unfortunately, data describing a selected characteristic of <span class="hlt">sediment</span> were not necessarily derived—collected, processed, analyzed, or interpreted—in a consistent manner. For example, <span class="hlt">bed-load</span> data collected with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70168614','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70168614"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span>-based metrics of wetland stability</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ganju, Neil K.; Kirwan, Matthew L.; Dickhudt, Patrick J.; Guntenspergen, Glenn R.; Cahoon, Donald R.; Kroeger, Kevin D.</p> <p>2015-01-01</p> <p>Despite the importance of <span class="hlt">sediment</span> availability on wetland stability, vulnerability assessments seldom consider spatiotemporal variability of <span class="hlt">sediment</span> <span class="hlt">transport</span>. Models predict that the maximum rate of sea level rise a marsh can survive is proportional to suspended <span class="hlt">sediment</span> concentration (SSC) and accretion. In contrast, we find that SSC and accretion are higher in an unstable marsh than in an adjacent stable marsh, suggesting that these metrics cannot describe wetland vulnerability. Therefore, we propose the flood/ebb SSC differential and organic-inorganic suspended <span class="hlt">sediment</span> ratio as better vulnerability metrics. The unstable marsh favors <span class="hlt">sediment</span> export (18 mg L−1 higher on ebb tides), while the stable marsh imports <span class="hlt">sediment</span> (12 mg L−1 higher on flood tides). The organic-inorganic SSC ratio is 84% higher in the unstable marsh, and stable isotopes indicate a source consistent with marsh-derived material. These simple metrics scale with <span class="hlt">sediment</span> fluxes, integrate spatiotemporal variability, and indicate <span class="hlt">sediment</span> sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70171414','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70171414"><span>Flow resistance under conditions of intense gravel <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pitlick, John</p> <p>1992-01-01</p> <p>A study of flow resistance was undertaken in a channelized reach of the North Fork Toutle River, downstream of Mount St. Helens, Washington. Hydraulic and <span class="hlt">sediment</span> <span class="hlt">transport</span> data were collected in flows with velocities up to 3 m/s and shear stresses up to 7 times the critical value needed for <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>. Details of the flow structure as revealed in vertical velocity profiles indicate that weak <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> over a plane gravel bed has little effect on flow resistance. The plane gravel bed persists up to stresses ∼3 times critical, at which point, irregular bed forms appear. Bed forms greatly increase flow resistance and cause velocity profiles to become distorted. The latter arises as an effect of flows becoming depth-limited as bed form amplitude increases. At very high rates of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>, an upper stage plane bed appeared. Velocity profiles measured in these flows match the law of the wall closely, with the equivalent roughness being well represented by ks = 3D84 of the <span class="hlt">bed</span> <span class="hlt">load</span>. The effects noted here will be important in very large floods or in rivers that are not free to widen, such as those cut into bedrock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUSM.B73A..10G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUSM.B73A..10G"><span>Pore Water PAH <span class="hlt">Transport</span> in Amended <span class="hlt">Sediment</span> Caps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gidley, P. T.; Kwon, S.; Ghosh, U.</p> <p>2009-05-01</p> <p>Capping is a common remediation strategy for contaminated <span class="hlt">sediments</span> that creates a physical barrier between contaminated <span class="hlt">sediments</span> and the water column. Diffusive flux of contaminants through a <span class="hlt">sediment</span> cap is small. However, under certain hydrodynamic conditions such as groundwater potential and tidal pumping, groundwater advection can accelerate contaminant <span class="hlt">transport</span>. Hydrophobic organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) could be <span class="hlt">transported</span> through the cap under advective conditions. To better understand PAH migration under these conditions, physical models of <span class="hlt">sediment</span> caps were evaluated in the laboratory through direct measurement of pore water using solid phase micro-extraction with gas chromatography and mass spectrometry. Contaminated <span class="hlt">sediment</span> and capping material was obtained from an existing Superfund site that was capped at Eagle Harbor, Washington. A PAH dissolution model linked to an advection-dispersion equation with retardation using published organic carbon-water partitioning coefficients (Koc) was compared to measured PAHs in the <span class="hlt">sediment</span> and cap porewater of the physical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMNH41A1757J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMNH41A1757J"><span>Uncertainty in the Modeling of Tsunami <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaffe, B. E.; Sugawara, D.; Goto, K.; Gelfenbaum, G. R.; La Selle, S.</p> <p>2016-12-01</p> <p>Erosion and deposition from tsunamis record information about tsunami hydrodynamics and size that can be interpreted to improve tsunami hazard assessment. A recent study (Jaffe et al., 2016) explores sources and methods for quantifying uncertainty in tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling. Uncertainty varies with tsunami properties, study site characteristics, available input data, <span class="hlt">sediment</span> grain size, and the model used. Although uncertainty has the potential to be large, case studies for both forward and inverse models have shown that <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling provides useful information on tsunami inundation and hydrodynamics that can be used to improve tsunami hazard assessment. New techniques for quantifying uncertainty, such as Ensemble Kalman Filtering inversion, and more rigorous reporting of uncertainties will advance the science of tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling. Uncertainty may be decreased with additional laboratory studies that increase our understanding of the semi-empirical parameters and physics of tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span>, standardized benchmark tests to assess model performance, and the development of hybrid modeling approaches to exploit the strengths of forward and inverse models. As uncertainty in tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling is reduced, and with increased ability to quantify uncertainty, the geologic record of tsunamis will become more valuable in the assessment of tsunami hazard. Jaffe, B., Goto, K., Sugawara, D., Gelfenbaum, G., and La Selle, S., "Uncertainty in Tsunami <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Modeling", Journal of Disaster Research Vol. 11 No. 4, pp. 647-661, 2016, doi: 10.20965/jdr.2016.p0647 https://www.fujipress.jp/jdr/dr/dsstr001100040647/</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/bul/1181a/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/bul/1181a/report.pdf"><span>Fluvial <span class="hlt">sediments</span> a summary of source, <span class="hlt">transportation</span>, deposition, and measurement of <span class="hlt">sediment</span> discharge</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Colby, B.R.</p> <p>1963-01-01</p> <p>This paper presents a broad but undetailed picture of fluvial <span class="hlt">sediments</span> in streams, reservoirs, and lakes and includes a discussion of the processes involved in the movement of <span class="hlt">sediment</span> by flowing water. <span class="hlt">Sediment</span> is fragmental material that originates from the chemical or physical disintegration of rocks. The disintegration products may have many different shapes and may range in size from large boulders to colloidal particles. In general, they retain about the same mineral composition as the parent rocks. Rock fragments become fluvial <span class="hlt">sediment</span> when they are entrained in a stream of water. The entrainment may occur as sheet erosion from land surfaces, particularly for the fine particles, or as channel erosion after the surface runoff has accumulated in streams. Fluvial <span class="hlt">sediments</span> move in streams as bedload (particles moving within a few particle diameters of the streambed) or as suspended <span class="hlt">sediment</span> in the turbulent flow. The discharge of bedload varies with several factors, which may include particle size and a type of effective shear on the surface of the streambed. The discharge of suspended <span class="hlt">sediment</span> depends partly on concentration of moving <span class="hlt">sediment</span> near the streambed and hence on discharge of bedload. However, the concentration of fine <span class="hlt">sediment</span> near the streambed varies widely, even for equal flows, and, therefore, the discharge of fine <span class="hlt">sediment</span> normally cannot be computed theoretically. The discharge of suspended <span class="hlt">sediment</span> also depends on velocity, turbulence, depth of flow, and fall velocity of the particles. In general, the coarse <span class="hlt">sediment</span> <span class="hlt">transported</span> by a stream moves intermittently and is discharged at a rate that depends on properties of the flow and of the <span class="hlt">sediment</span>. If an ample supply of coarse <span class="hlt">sediment</span> is available at the surface of the streambed, the discharge of the coarse <span class="hlt">sediment</span>, such as sand, can be roughly computed from properties of the available <span class="hlt">sediment</span> and of the flow. On the other hand, much of the fine <span class="hlt">sediment</span> in a stream usually moves nearly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://dx.doi.org/10.1016/j.csr.2012.02.010','USGSPUBS'); return false;" href="http://dx.doi.org/10.1016/j.csr.2012.02.010"><span>Modeling <span class="hlt">transport</span> and deposition of the Mekong River <span class="hlt">sediment</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Xue, Zuo; He, Ruoying; Liu, J. Paul; Warner, John C.</p> <p>2012-01-01</p> <p>A Coupled Wave–Ocean–<span class="hlt">SedimentTransport</span> Model was used to hindcast coastal circulation and fine sedimenttransport on the Mekong shelf in southeastern Asian in 2005. Comparisons with limited observations showed that the model simulation captured the regional patterns and temporal variability of surface wave, sea level, and suspended <span class="hlt">sediment</span> concentration reasonably well. Significant seasonality in sedimenttransport was revealed. In summer, a large amount of fluvial <span class="hlt">sediments</span> was delivered and deposited near the MekongRiver mouth. In the following winter, strong ocean mixing, and coastal current lead to resuspension and southwestward dispersal of a small fraction of previously deposited <span class="hlt">sediments</span>. Model sensitivity experiments (with reduced physics) were performed to investigate the impact of tides, waves, and remotely forced ambient currents on the <span class="hlt">transport</span> and dispersal of the fluvial <span class="hlt">sediment</span>. Strong wave mixing and downwelling-favorable coastal current associated with the more energetic northeast monsoon in the winter season are the main factors controlling the southwestward along-shelf <span class="hlt">transport</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70189796','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70189796"><span>On extracting <span class="hlt">sediment</span> <span class="hlt">transport</span> information from measurements of luminescence in river <span class="hlt">sediment</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gray, Harrison J.; Tucker, Gregory E.; Mahan, Shannon; McGuire, Chris; Rhodes, Edward J.</p> <p>2017-01-01</p> <p>Accurately quantifying <span class="hlt">sediment</span> <span class="hlt">transport</span> rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring long-time scale (102–106 years) <span class="hlt">transport</span> rates are laborious, and formulae to predict <span class="hlt">transport</span> are notoriously inaccurate. Here we attempt to estimate <span class="hlt">sediment</span> <span class="hlt">transport</span> rates by using luminescence, a property of common sedimentary minerals that is used by the geoscience community for geochronology. This method is advantageous because of the ease of measurement on ubiquitous quartz and feldspar sand. We develop a model from first principles by using conservation of energy and <span class="hlt">sediment</span> mass to explain the downstream pattern of luminescence in river channel <span class="hlt">sediment</span>. We show that the model can accurately reproduce the luminescence observed in previously published field measurements from two rivers with very different <span class="hlt">sediment</span> <span class="hlt">transport</span> styles. The model demonstrates that the downstream pattern of river sand luminescence should show exponential-like decay in the headwaters which asymptotes to a constant value with further downstream distance. The parameters from the model can then be used to estimate the time-averaged virtual velocity, characteristic <span class="hlt">transport</span> lengthscale, storage time scale, and floodplain exchange rate of fine sand-sized <span class="hlt">sediment</span> in a fluvial system. The <span class="hlt">sediment</span> <span class="hlt">transport</span> values predicted from the luminescence method show a broader range than those reported in the literature, but the results are nonetheless encouraging and suggest that luminescence demonstrates potential as a <span class="hlt">sediment</span> <span class="hlt">transport</span> indicator. However, caution is warranted when applying the model as the complex nature of <span class="hlt">sediment</span> <span class="hlt">transport</span> can sometimes invalidate underlying simplifications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913488R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913488R"><span>The role of the hyporheic flow on <span class="hlt">sediment</span> <span class="hlt">transport</span> processes : an experimental approach using particle image velocimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rousseau, Gauthier; Sklivaniti, Angeliki; Vito Papa, Daniel; Ancey, Christophe</p> <p>2017-04-01</p> <p>The study of river dynamics usually considers a turbulent stream on an impervious bed. However, it is known that part of the total discharge takes place through the erodible bed, especially for mountain rivers. This hyporheic flow (or subsurface flow) is likely to play an active role in the stability of the erodible bed. The question then arises: How does the hyporheic flow affect bed stability and thereby <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>? Monitoring hyporheic flow under natural conditions remains a key challenge. Laboratory experiments and new measurement techniques shed new light on this problem. Using PIV-LIF method (Particle Image Velocimetry - Laser Induced Fluorescence) we investigate hyporheic flows through erodible beds. The experiment is conducted in a 2-m-long and 6-cm-width flume with 2-mm-diameter glass beads and 4-mm-diameter natural pebbles under turbulent stream conditions. In parallel, we develop a simple analytical model that accounts for the interaction between the surface and subsurface flows at the bed interface. As the Reynolds number of the hyporheic flow is fairly high (10 to 100), inertia cannot be neglected. This leads us to use the Darcy-Forchheimer law instead of Darcy's law to model hyporheic flows. We show that this model is consistent with the PIV-LIF experimental results. Moreover, the PIV-LIF data show that hyporheic flows modify the velocity profile and turbulence. Our measurements and empirical model emphasize the exchange processes in coarse-grained river for incipient <span class="hlt">sediment</span> motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wsp/2008/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wsp/2008/report.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> in a Mississippi River distributary-- Bayou Lafourche, Louisiana</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Doyle, W. Harry</p> <p>1972-01-01</p> <p>The installation of a pumping plant at Donaldsonville, La., in 1955 to solve a water-supply problem for the residents along Bayou Lafourche created a <span class="hlt">sedimentation</span> problem in the bayou. Prior to 1904, when the bayou functioned as a distributary, floodflows periodically scoured the <span class="hlt">sediment</span> deposited in the channel at lower stages. Nearly constant flows maintained by the pumping plant result in limited <span class="hlt">transport</span> capacity to move the <span class="hlt">sediment</span> imposed on the channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5884405-suspending-sediment-transport-sedimentation-resuspension-lake-houston-texas-implications-water-quality','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5884405-suspending-sediment-transport-sedimentation-resuspension-lake-houston-texas-implications-water-quality"><span>Suspending <span class="hlt">sediment</span> <span class="hlt">transport</span>, <span class="hlt">sedimentation</span>, and resuspension in Lake Houston, Texas: Implications for water quality</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Matty, J.M.; Anderson, J.B.; Dunbar, R.B.</p> <p>1987-01-01</p> <p>Lake Houston is a man-made reservoir located northeast of Houston, Texas. The purpose of this investigation was to document suspended <span class="hlt">sediment</span> <span class="hlt">transport</span>, <span class="hlt">sedimentation</span>, and resuspension in the lake with a view towards estimating the influence of <span class="hlt">sedimentation</span> on water quality. <span class="hlt">Sediment</span> traps were placed in strategic locations in the lake to collect suspended <span class="hlt">sediments</span>. Samples were analyzed for bulk density, grain size, organic carbon, and a number of trace elements. These data were analyzed along with meteorological data to examine those factors which regulate suspended <span class="hlt">sediment</span> input and dispersal, and the role of suspended <span class="hlt">sediments</span> in controlling water quality withinmore » the lake. <span class="hlt">Sediment</span> input to the lake depends primarily on the intensity of rainfall in the watershed. <span class="hlt">Sediment</span> movement within the lake is strongly influenced by wave activity, which resuspends <span class="hlt">sediments</span> from shallow areas, and by wind-driven circulation. The increased residence time of suspended <span class="hlt">sediments</span> due to resuspension allows greater decomposition of organic matter and the release of several trace elements from <span class="hlt">sediments</span> to the water column. Virtually all samples from <span class="hlt">sediment</span> traps suspended between 1 and 5 m above the lake bottom contain medium to coarse silt, and even some very fine sand-sized material. This implies that circulation in Lake Houston is periodically intense enough to <span class="hlt">transport</span> this size material in suspension. During winter, northerly winds with sustained velocities of greater than 5 m/sec provide the most suitable condition for rapid (< 1 d) <span class="hlt">transport</span> of suspended <span class="hlt">sediment</span> down the length of the lake. Fluctuations in current velocities and the subsequent suspension/deposition of particles may explain variations in the abundance of coliform bacteria in Lake Houston.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1911975P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911975P"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> in the area of the Sopot pier</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Przyborska, Anna; Jakacki, Jaromir; Andrzejewski, Jan</p> <p>2017-04-01</p> <p>Coastal <span class="hlt">sediment</span> <span class="hlt">transport</span> is a natural process that appears when energy of waves is sufficient for moving solid particles from the bottom. <span class="hlt">Sediment</span> <span class="hlt">transport</span> rate depends on the median diameter of local sand and it is compatible with the direction of wave propagation. Also it is natural, that any protruded from the beach construction disturbs continuity of beach <span class="hlt">transport</span> caused by waves. The Sopot pier has been built over 100 years ago and it is the longest wooden pier on the Baltic Sea coast, it is about half kilometre long. The pier is located at the end of the Monte Casino street and it is one of the biggest attractions of the city as well as in the country. In the past and now we have observed the disturbed <span class="hlt">sediment</span> <span class="hlt">transport</span> in the area of the Sopot pier. But during recent years, this process has gained greater momentum. The beach at the Sopot pier has been growing by several meters. All indicates that the cause of the observed phenomenon is the marina. The marina structure which is in some distance from the shore, has been acting as a powerful, emerged breakwater boundary. As a tool the <span class="hlt">sediment</span> <span class="hlt">transport</span> model was implemented for Sopot pier area. The implemented numerical forecasting <span class="hlt">sediment</span> <span class="hlt">transport</span> model in the area of the Sopot pier reflects well the deposit growth rate for the archived data from 2010 to 2015. On the basis of differences in bathymetry data provided by the Maritime office and the analysis the model results the average deposits in accumulation in the pear area was determined to be about 16,000 m3 / year for the assumed area of analysis, the model have shown similar result. The analysis suggests that strong winds generating significant waves as well as meaningful <span class="hlt">sediment</span> <span class="hlt">transport</span> dominate in the autumn and winter. You cannot, however, rule out strong waves in summer. Under moderate waves the <span class="hlt">sediment</span> <span class="hlt">transport</span> is insignificant. The most intense movement of the <span class="hlt">sediment</span> is observed in the vicinity of the shoreline, it disappears with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7887','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7887"><span>Bankfull discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> in northwestern California</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>K. M. Nolan; T. E. Lisle; H. M. Kelsey</p> <p>1987-01-01</p> <p>Abstract - High-magnitude, low-frequency discharges are more responsible for <span class="hlt">transporting</span> suspended <span class="hlt">sediment</span> and forming channels in northwestern California than in previously studied areas. Bankfull discharge and the magnitude and frequency of suspended <span class="hlt">sediment</span> discharge were determined at five gaging stations in northwestern California. Although discharges below...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=300958','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=300958"><span>Seasonal <span class="hlt">sediment</span> and nutrients <span class="hlt">transport</span> patterns</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>It is essential to understand <span class="hlt">sediment</span> and nutrient sources and their spatial and temporal patterns in order to design effective mitigation strategies. However, long-term data sets to determine <span class="hlt">sediment</span> and nutrient loadings are scarce and expensive to collect. The goal of this study was to determin...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CSR...129....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CSR...129....1S"><span><span class="hlt">Sediment</span> dynamics and their potential influence on insular-slope mesophotic coral ecosystems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sherman, C.; Schmidt, W.; Appeldoorn, R.; Hutchinson, Y.; Ruiz, H.; Nemeth, M.; Bejarano, I.; Motta, J. J. Cruz; Xu, H.</p> <p>2016-10-01</p> <p>Although <span class="hlt">sediment</span> dynamics exert a fundamental control on the character and distribution of reefs, data on <span class="hlt">sediment</span> dynamics in mesophotic systems are scarce. In this study, <span class="hlt">sediment</span> traps and benthic photo-transects were used to document spatial and temporal patterns of suspended-<span class="hlt">sediment</span> and <span class="hlt">bed-load</span> dynamics at two geomorphically distinct mesophotic coral ecosystems (MCEs) on the upper insular slope of southwest Puerto Rico. Trap accumulation rates of suspended <span class="hlt">sediment</span> were relatively low and spatiotemporally uniform, averaging <1 mg cm-2 d-1 and never exceeding 3 mg cm-2 d-1 over the sampled period. In contrast, trap accumulation rates of downslope <span class="hlt">bed-load</span> movement were orders of magnitude higher than suspended-<span class="hlt">sediment</span> accumulation rates and highly variable, by orders of magnitude, both spatially and temporally. Percent sand cover within photo-transects varied over time from 10% to more than 40% providing further evidence of downslope <span class="hlt">sediment</span> movement. In general, the more exposed, lower gradient site had higher rates of downslope <span class="hlt">sediment</span> movement, higher sand cover and lower coral cover than the more sheltered and steep site that exhibited lower rates of downslope <span class="hlt">sediment</span> movement, lower sand cover and higher coral cover. In most cases, trap accumulation rates of suspended <span class="hlt">sediment</span> and <span class="hlt">bed</span> <span class="hlt">load</span> varied together and peaks in trap accumulation rates correspond to peaks in SWAN-modeled wave-orbital velocities, suggesting that surface waves may influence <span class="hlt">sediment</span> dynamics even in mesophotic settings. Though variable, off-shelf <span class="hlt">transport</span> of <span class="hlt">sediment</span> is a continuous process occurring even during non-storm conditions. Continuous downslope <span class="hlt">sediment</span> movement in conjunction with degree of exposure to prevailing seas and slope geomorphology are proposed to exert an important influence on the character and distribution of insular-slope MCEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1984/4141/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1984/4141/report.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> in the Lower Yampa River, Northwestern Colorado</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Elliott, John G.; Kircher, James E.; Von Guerard, Paul</p> <p>1984-01-01</p> <p>Discharge measurements and <span class="hlt">sediment</span> samples were taken at streamflow-gaging station 09260050 Yampa River at Deerlodge Park in 1982 and 1983 to determine the annual <span class="hlt">sediment</span> supply to the Yampa Canyon in Dinosaur National Monument. Forty-three years of discharge records at two tributary sites were combined to determine the historic discharge of the Yampa River at Deerlodge Park. A mean annual hydrograph and flow-duration curve were derived from these data. <span class="hlt">Sediment-transport</span> equations were derived for total <span class="hlt">sediment</span> discharge, suspended-<span class="hlt">sediment</span> discharge, bedload dischagre, and the discharge of <span class="hlt">sediment</span> in several particle-sizes. Annual <span class="hlt">sediment</span> discharge were determined by the flow-duration, <span class="hlt">sediment</span>-rating-curve method and indicated annual total <span class="hlt">sediment</span> discharge was approximately 2.0 million tons per year of which 0.8 million tons per year was sand-sized material. Bedload was almost entirely sand, and annual bedload discharge was 0.1 million tons per year. Development of water resources in the Yampa River basin could effect the geomorphic character of the Yampa River at Deerlodge Park and the Yampa Canyon. Several scenarios of altered streamflow frequency distribution, reduced streamflow volume, and reduced <span class="hlt">sediment</span> supply are examined to estimate the effect on the <span class="hlt">sediment</span> budget at Deerlodge Park. (USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7852','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7852"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and resulting deposition in spawning gravels, north coastal California</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas E. Lisle</p> <p>1989-01-01</p> <p>Incubating salmonid eggs in streambeds are often threatened by deposition of fine <span class="hlt">sediment</span> within the gravel. To relate <span class="hlt">sedimentation</span> of spawning gravel beds to <span class="hlt">sediment</span> <span class="hlt">transport</span>, infiltration of fine <span class="hlt">sediment</span> (</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP53E1026H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP53E1026H"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Dynamics and Bedform Evolution During Unsteady Flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, H.; Parsons, D. R.; Ockelford, A.; Hardy, R. J.; Ashworth, P. J.; Best, J.</p> <p>2016-12-01</p> <p>Dunes are ubiquitous features in sand bed rivers and estuaries, and their formation, growth and kinematics play a dominant role in boundary flow structure, flow resistance and <span class="hlt">sediment</span> <span class="hlt">transport</span> processes. However, bedform evolution and dynamics during the rising/falling limb of a flood wave remain poorly understood. Herein, we report on a series of flume experiments, undertaken at the University of Hull's Total Environment Simulator flume/wave tank facility, with imposed flow variations and different hydrographs: i) a sudden (shock) change, ii) a fast flood wave and iii) a slow flood wave. Our analysis shows that, because of changes of <span class="hlt">sediment</span> <span class="hlt">transport</span> mechanisms with discharge, the <span class="hlt">sediment</span> flux rather than bedform migration rate is a more appropriate parameter to relate to <span class="hlt">transport</span> stage. This is particularly the case during bedload <span class="hlt">transport</span> dominated periods at lower flow discharge, where a strong power law relationship was detected. In terms of varying processes across the hydrograph limbs, bedform evolution during the rising limb is dominated not only by bedform amalgamation but also by the washing out of smaller-scale bedforms. Furthermore, bedform growth is independent of the rising rate of the hydrograph limb, while evolution of bedform decay is affected by the rate of discharge decrease. This results in an anticlockwise hysteresis between <span class="hlt">transport</span> stage and total flux was found in fast wave experiment, indicating a significant role of the change in <span class="hlt">sediment</span> <span class="hlt">transport</span> mechanisms on bedform evolution. Moreover, analysis on the variation of deformation fraction (F, ratio of the deformation flux to the total bed material flux) suggests that net degradation of the bed enhances bedform deformation and leads to a higher F ( 0.65). This work extends our knowledge on how dunes generate and develop under variable flows and has begun to explore how variations in <span class="hlt">transport</span> stage can be coupled with the variation in <span class="hlt">sediment</span> <span class="hlt">transport</span> mechanisms, and/or <span class="hlt">sediment</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70026604','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70026604"><span>Process based modeling of total longshore <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Haas, K.A.; Hanes, D.M.</p> <p>2004-01-01</p> <p>Waves, currents, and longshore sand <span class="hlt">transport</span> are calculated locally as a function of position in the nearshore region using process based numerical models. The resultant longshore sand <span class="hlt">transport</span> is then integrated across the nearshore to provide predictions of the total longshore <span class="hlt">transport</span> of sand due to waves and longshore currents. Model results are in close agreement with the I1-P1 correlation described by Komar and Inman (1970) and the CERC (1984) formula. Model results also indicate that the proportionality constant in the I1-P1 formula depends weakly upon the <span class="hlt">sediment</span> size, the shape of the beach profile, and the particular local <span class="hlt">sediment</span> flux formula that is employed. Model results indicate that the various effects and influences of <span class="hlt">sediment</span> size tend to cancel out, resulting in little overall dependence on <span class="hlt">sediment</span> size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HESS...18.3033M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HESS...18.3033M"><span>Large-scale suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> and <span class="hlt">sediment</span> deposition in the Mekong Delta</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manh, N. V.; Dung, N. V.; Hung, N. N.; Merz, B.; Apel, H.</p> <p>2014-08-01</p> <p><span class="hlt">Sediment</span> dynamics play a major role in the agricultural and fishery productivity of the Mekong Delta. However, the understanding of <span class="hlt">sediment</span> dynamics in the delta, one of the most complex river deltas in the world, is very limited. This is a consequence of its large extent, the intricate system of rivers, channels and floodplains, and the scarcity of observations. This study quantifies, for the first time, the suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> and <span class="hlt">sediment</span> deposition in the whole Mekong Delta. To this end, a quasi-2D hydrodynamic model is combined with a cohesive <span class="hlt">sediment</span> <span class="hlt">transport</span> model. The combined model is calibrated using six objective functions to represent the different aspects of the hydraulic and <span class="hlt">sediment</span> <span class="hlt">transport</span> components. The model is calibrated for the extreme flood season in 2011 and shows good performance for 2 validation years with very different flood characteristics. It is shown how <span class="hlt">sediment</span> <span class="hlt">transport</span> and <span class="hlt">sediment</span> deposition is differentiated from Kratie at the entrance of the delta on its way to the coast. The main factors influencing the spatial <span class="hlt">sediment</span> dynamics are the river and channel system, dike rings, sluice gate operations, the magnitude of the floods, and tidal influences. The superposition of these factors leads to high spatial variability of <span class="hlt">sediment</span> <span class="hlt">transport</span>, in particular in the Vietnamese floodplains. Depending on the flood magnitude, annual <span class="hlt">sediment</span> loads reaching the coast vary from 48 to 60% of the <span class="hlt">sediment</span> load at Kratie. Deposited <span class="hlt">sediment</span> varies from 19 to 23% of the annual load at Kratie in Cambodian floodplains, and from 1 to 6% in the compartmented and diked floodplains in Vietnam. Annual deposited nutrients (N, P, K), which are associated with the <span class="hlt">sediment</span> deposition, provide on average more than 50% of mineral fertilizers typically applied for rice crops in non-flooded ring dike floodplains in Vietnam. Through the quantification of <span class="hlt">sediment</span> and related nutrient input, the presented study provides a quantitative basis for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2008/1340/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2008/1340/"><span>Incorporation of Fine-Grained <span class="hlt">Sediment</span> Erodibility Measurements into <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Modeling, Capitol Lake, Washington</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stevens, Andrew W.; Gelfenbaum, Guy; Elias, Edwin; Jones, Craig</p> <p>2008-01-01</p> <p>Capitol Lake was created in 1951 with the construction of a concrete dam and control gate that prevented salt-water intrusion into the newly formed lake and regulated flow of the Deschutes River into southern Puget Sound. Physical processes associated with the former tidally dominated estuary were altered, and the dam structure itself likely caused an increase in retention of <span class="hlt">sediment</span> flowing into the lake from the Deschutes River. Several efforts to manage <span class="hlt">sediment</span> accumulation in the lake, including dredging and the construction of <span class="hlt">sediment</span> traps upriver, failed to stop the lake from filling with <span class="hlt">sediment</span>. The Deschutes Estuary Feasibility Study (DEFS) was carried out to evaluate the possibility of removing the dam and restoring estuarine processes as an alternative ongoing lake management. An important component of DEFS was the creation of a hydrodynamic and <span class="hlt">sediment</span> <span class="hlt">transport</span> model of the restored Deschutes Estuary. Results from model simulations indicated that estuarine processes would be restored under each of four restoration alternatives, and that over time, the restored estuary would have morphological features similar to the predam estuary. The model also predicted that after dam-removal, a large portion of the <span class="hlt">sediment</span> eroded from the lake bottom would be deposited near the Port of Olympia and a marina located in lower Budd Inlet seaward of the present dam. The volume of <span class="hlt">sediment</span> <span class="hlt">transported</span> downstream was a critical piece of information that managers needed to estimate the total cost of the proposed restoration project. However, the ability of the model to predict the magnitude of <span class="hlt">sediment</span> <span class="hlt">transport</span> in general and, in particular, the volume of <span class="hlt">sediment</span> deposition in the port and marina was limited by a lack of information on the erodibility of fine-grained <span class="hlt">sediments</span> in Capitol Lake. Cores at several sites throughout Capitol Lake were collected between October 31 and November 1, 2007. The erodibility of <span class="hlt">sediments</span> in the cores was later determined in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70111258','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70111258"><span><span class="hlt">Transport</span> of fine <span class="hlt">sediment</span> over a coarse, immobile riverbed</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Grams, Paul E.; Wilcock, Peter R.</p> <p>2014-01-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> in cobble-boulder rivers consists mostly of fine <span class="hlt">sediment</span> moving over a coarse, immobile bed. <span class="hlt">Transport</span> rate depends on several interrelated factors: boundary shear stress, the grain size and volume of fine <span class="hlt">sediment</span>, and the configuration of fine <span class="hlt">sediment</span> into interstitial deposits and bed forms. Existing models do not incorporate all of these factors. Approaches that partition stress face a daunting challenge because most of the boundary shear is exerted on immobile grains. We present an alternative approach that divides the bed into sand patches and interstitial deposits and is well constrained by two clear end-member cases: full sand cover and absence of sand. Entrainment from sand patches is a function of their aerial coverage. Entrainment from interstices among immobile grains is a function of sand elevation relative to the size of the immobile grains. The bed-sand coverage function is used to predict the ratio of the rate of entrainment from a partially covered bed to the rate of entrainment from a completely sand-covered bed, which is determined using a standard sand <span class="hlt">transport</span> model. We implement the bed-sand coverage function in a morphodynamic routing model and test it against observations of sand bed elevation and suspended sand concentration for conditions of nonuniform fine <span class="hlt">sediment</span> <span class="hlt">transport</span> in a large flume with steady uniform flow over immobile hemispheres. The results suggest that this approach may provide a simple and robust method for predicting the <span class="hlt">transport</span> and migration of fine <span class="hlt">sediment</span> through rivers with coarse, immobile beds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3232S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3232S"><span>Effect of large wood retention at check dams on <span class="hlt">sediment</span> continuity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmocker, Lukas; Schalko, Isabella; Weitbrecht, Volker</p> <p>2017-04-01</p> <p>Large wood <span class="hlt">transport</span> during flood events may seriously increase the damage potential due to accumulations at river infrastructures. The large wood is therefore mostly retained upstream of populated areas using retention structures that often combine a check dam with a debris rack. One disadvantages of this structures is, that the <span class="hlt">bed-load</span> gets retained along with the wood. Especially if large wood blocks the rack early during a flood event, <span class="hlt">sediment</span> continuity is completely interrupted. This may lead to severe bed erosion downstream of the check dam. So far, no common design to retain large wood but maintain <span class="hlt">sediment</span> continuity is available. One attempt to separate the large wood from the <span class="hlt">bed-load</span> was made with the large wood retention structure at River Sihl in Zürich, Switzerland. The retention of the large wood occurs in a bypass channel located along the main river. The bypass is located at an outer river bend, where a separation of <span class="hlt">bed-load</span> and large wood results due to the secondary currents induced by the river curvature. Large wood floats towards the outer bend due to inertia and the secondary currents whereas <span class="hlt">bed-load</span> remains at the inner bend. The bypass is separated by a side weir from the main river to ensure that the <span class="hlt">bed-load</span> remains in the river during bed forming discharges and flood events. New model test are currently carried out at the Laboratory of Hydraulics, Hydrology, and Glaciology (VAW) of ETH Zurich, where <span class="hlt">sediment</span> continuity should be achieved using an inclined rack. The rack is inclined in flow direction with a degree of 45° to 20°. First results show that the large wood deposits at the upper part of the rack whereas the lower part of the rack remains free for <span class="hlt">bed-load</span> <span class="hlt">transport</span>. Furthermore, the backwater rise for the inclined rack due to the accumulated wood is considerably reduced compared to a vertical rack, as a large part of the rack remains clear for the flow to pass. The findings of this studies help to understand the complex</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70162285','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70162285"><span><span class="hlt">Sediment</span> supply versus local hydraulic controls on <span class="hlt">sediment</span> <span class="hlt">transport</span> and storage in a river with large <span class="hlt">sediment</span> loads</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dean, David; Topping, David; Schmidt, John C.; Griffiths, Ronald; Sabol, Thomas</p> <p>2016-01-01</p> <p>The Rio Grande in the Big Bend region of Texas, USA, and Chihuahua and Coahuila, Mexico, undergoes rapid geomorphic changes as a result of its large <span class="hlt">sediment</span> supply and variable hydrology; thus, it is a useful natural laboratory to investigate the relative importance of flow strength and <span class="hlt">sediment</span> supply in controlling alluvial channel change. We analyzed a suite of <span class="hlt">sediment</span> <span class="hlt">transport</span> and geomorphic data to determine the cumulative influence of different flood types on changing channel form. In this study, physically based analyses suggest that channel change in the Rio Grande is controlled by both changes in flow strength and <span class="hlt">sediment</span> supply over different spatial and temporal scales. Channel narrowing is primarily caused by substantial deposition of <span class="hlt">sediment</span> supplied to the Rio Grande during tributary-sourced flash floods. Tributary floods have large suspended-<span class="hlt">sediment</span> concentrations, occur for short durations, and attenuate rapidly downstream in the Rio Grande, depositing much of their <span class="hlt">sediment</span> in downstream reaches. Long-duration floods on the mainstem have the capacity to enlarge the Rio Grande, and these floods, released from upstream dams, can either erode or deposit <span class="hlt">sediment</span> in the Rio Grande depending upon the antecedent in-channel <span class="hlt">sediment</span> supply and the magnitude and duration of the flood. Geomorphic and <span class="hlt">sediment</span> <span class="hlt">transport</span> analyses show that the locations and rates of sand erosion and deposition during long-duration floods are most strongly controlled by spatial changes in flow strength, largely through changes in channel slope. However, spatial differences in the in-channel <span class="hlt">sediment</span> supply regulate <span class="hlt">sediment</span> evacuation or accumulation over time in long reaches (greater than a kilometer).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/7825','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/7825"><span>Overview: Channel morphology and <span class="hlt">sediment</span> <span class="hlt">transport</span> in steepland streams</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>T. E. Lisle</p> <p>1987-01-01</p> <p>Abstract - New understanding of how steepland channels formed is being pursued over a large range of scales, from entrainment of bed particles to the transfer of stored <span class="hlt">sediment</span> down channel systems. Low submergence of bed particles during <span class="hlt">transport</span> and wide heterogeneity in particle sizes strongly affect bedload <span class="hlt">transport</span>. At the scale of a reach, scour-lobes are...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA578445','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA578445"><span>A Unified <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Model for Inlet Application</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-01-01</p> <p>of the development was to arrive at general <span class="hlt">sediment</span> <span class="hlt">transport</span> formulas suitable for a wide range of hydrodynamic, sedimentologic , and morphologic...wide range of hydrodynamic, sedimentologic , and morphologic conditions that yield reliable and robust predictions. In this paper such formulas are...hydrodynamic, sedimentologic , and morphologic conditions that prevail around coastal inlets. Thus, the formulas yield <span class="hlt">transport</span> rates under waves and currents</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037347','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037347"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> on the Palos Verdes shelf, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ferre, B.; Sherwood, C.R.; Wiberg, P.L.</p> <p>2010-01-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> and the potential for erosion or deposition have been investigated on the Palos Verdes (PV) and San Pedro shelves in southern California to help assess the fate of an effluent-affected deposit contaminated with DDT and PCBs. Bottom boundary layer measurements at two 60-m sites in spring 2004 were used to set model parameters and evaluate a one-dimensional (vertical) model of local, steady-state resuspension, and suspended-<span class="hlt">sediment</span> <span class="hlt">transport</span>. The model demonstrated skill (Brier scores up to 0.75) reproducing the magnitudes of bottom shear stress, current speeds, and suspended-<span class="hlt">sediment</span> concentrations measured during an April <span class="hlt">transport</span> event, but the model tended to underpredict observed rotation in the bottom-boundary layer, possibly because the model did not account for the effects of temperature-salinity stratification. The model was run with wave input estimated from a nearby buoy and current input from four to six years of measurements at thirteen sites on the 35- and 65-m isobaths on the PV and San Pedro shelves. <span class="hlt">Sediment</span> characteristics and erodibility were based on gentle wet-sieve analysis and erosion-chamber measurements. Modeled flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> were mostly alongshelf toward the northwest on the PV shelf with a significant offshore component. The 95th percentile of bottom shear stresses ranged from 0.09 to 0.16 Pa at the 65-m sites, and the lowest values were in the middle of the PV shelf, near the Whites Point sewage outfalls where the effluent-affected layer is thickest. Long-term mean <span class="hlt">transport</span> rates varied from 0.9 to 4.8 metric tons m-1 yr-1 along the 65-m isobaths on the PV shelf, and were much higher at the 35-m sites. Gradients in modeled alongshore <span class="hlt">transport</span> rates suggest that, in the absence of a supply of <span class="hlt">sediment</span> from the outfalls or PV coast, erosion at rates of ???0.2 mm yr-1 might occur in the region southeast of the outfalls. These rates are small compared to some estimates of background natural <span class="hlt">sedimentation</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRF..117.3014M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRF..117.3014M"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> by runoff on debris-mantled dryland hillslopes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Michaelides, Katerina; Martin, Gareth J.</p> <p>2012-09-01</p> <p>Hillslopes supply <span class="hlt">sediment</span> to river channels, and therefore impact drainage basin functioning and evolution. The relationship between hillslope attributes and <span class="hlt">sediment</span> flux forms the basis of geomorphic <span class="hlt">transport</span> laws used to model the long-term topographic evolution of drainage basins, but their specific interactions during individual storm events are not well understood. Runoff-driven erosion of coarse particles, prevalent in dryland environments, presents a particular set of conditions for <span class="hlt">sediment</span> <span class="hlt">transport</span> that is poorly resolved in current models. In order to address this gap, we developed a particle-based, force-balance model for sheetwash <span class="hlt">sediment</span> <span class="hlt">transport</span> on coarse, debris-mantled hillslopes within a rainfall-runoff model. We use the model to examine how the interplay between hillslope attributes (gradient, length and grain size distribution) and runoff characteristics affects <span class="hlt">sediment</span> <span class="hlt">transport</span>, grain-size changes on the hillslope, and <span class="hlt">sediment</span> supply to the slope base. The relationship between <span class="hlt">sediment</span> flux and hillslope gradient was found to transition from linear above a threshold to sigmoidal depending on hillslope length, initial grain sizes, and runoff characteristics. Grain sizes supplied to the slope base vary in a complex manner with hillslope attributes but an overall coarsening of the hillslopes is found to occur with increasing gradient, corroborating previous findings from field measurements. Intense, short duration storms result in within-hillslope <span class="hlt">sediment</span> redistribution and equifinality in <span class="hlt">sediment</span> supply for different hillslope characteristics, which explain the lack of field evidence for any systematic relationships. Our model findings provide insights into hillslope responses to climatic forcing and have theoretical implications for modeling hillslope evolution in dry lands.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSMG54B2041N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSMG54B2041N"><span>Surface-<span class="hlt">sediment</span> grain-size distribution and <span class="hlt">sediment</span> <span class="hlt">transport</span> in the subaqueous Mekong Delta, Vietnam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen, T. T.; Stattegger, K.; Nittrouer, C.; Phung, P. V.; Liu, P.; DeMaster, D. J.; Bui, D. V.; Le, A. D.; Nguyen, T. N.</p> <p>2016-02-01</p> <p>Collected surface-<span class="hlt">sediment</span> samples in coastal water around Mekong Delta (from distributary channels to Ca Mau Peninsula) were analyzed to determine surface-<span class="hlt">sediment</span> grain-size distribution and <span class="hlt">sediment-transport</span> trend in the subaqueous Mekong Delta. The grain-size data set of 238 samples was obtained by using the laser instrument Mastersizer 2000 and LS Particle Size Analyzer. Fourteen samples were selected for geochemical analysis (total-organic and carbonate content). These geochemical results were used to assist in interpreting variations of granulometricparamenters along the cross-shore transects. Nine transects were examined from CungHau river mouth to Ca Mau Peninsula and six thematic maps on the whole study area were made. The research results indicate that: (1) generally, the <span class="hlt">sediment</span> becomes finer from the delta front downwards to prodelta and becomes coarser again and poorer sorted on the adjacent inner shelf due to different sources of <span class="hlt">sediment</span>; (2) <span class="hlt">sediment</span>-granulometry parameters vary among sedimentary sub-environments of the underwater part of Mekong Delta, the distance from <span class="hlt">sediment</span> source and hydrodynamic regime controlling each region; (3) the net <span class="hlt">sediment</span> <span class="hlt">transport</span> is southwest toward the Ca Mau Peninsula.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AcMSn..31..791C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AcMSn..31..791C"><span><span class="hlt">Transport</span> mechanisms of contaminants released from fine <span class="hlt">sediment</span> in rivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Pengda; Zhu, Hongwei; Zhong, Baochang; Wang, Daozeng</p> <p>2015-12-01</p> <p>Contaminants released from <span class="hlt">sediment</span> into rivers are one of the main problems to study in environmental hydrodynamics. For contaminants released into the overlying water under different hydrodynamic conditions, the mechanical mechanisms involved can be roughly divided into convective diffusion, molecular diffusion, and adsorption/desorption. Because of the obvious environmental influence of fine <span class="hlt">sediment</span> (D_{90}= 0.06 mm), non-cohesive fine <span class="hlt">sediment</span>, and cohesive fine <span class="hlt">sediment</span> are researched in this paper, and phosphorus is chosen for a typical adsorption of a contaminant. Through theoretical analysis of the contaminant release process, according to different hydraulic conditions, the contaminant release coupling mathematical model can be established by the N-S equation, the Darcy equation, the solute <span class="hlt">transport</span> equation, and the adsorption/desorption equation. Then, the experiments are completed in an open water flume. The simulation results and experimental results show that convective diffusion dominates the contaminant release both in non-cohesive and cohesive fine <span class="hlt">sediment</span> after their suspension, and that they contribute more than 90 % of the total release. Molecular diffusion and desorption have more of a contribution for contaminant release from unsuspended <span class="hlt">sediment</span>. In unsuspension <span class="hlt">sediment</span>, convective diffusion is about 10-50 times larger than molecular diffusion during the initial stages under high velocity; it is close to molecular diffusion in the later stages. Convective diffusion is about 6 times larger than molecular diffusion during the initial stages under low velocity, it is about a quarter of molecular diffusion in later stages, and has a similar level with desorption/adsorption. In unsuspended <span class="hlt">sediment</span>, a seepage boundary layer exists below the water-<span class="hlt">sediment</span> interface, and various release mechanisms in that layer mostly dominate the contaminant release process. In non-cohesive fine <span class="hlt">sediment</span>, the depth of that layer increases linearly with shear</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1411935B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1411935B"><span>Coupling a basin erosion and river <span class="hlt">sediment</span> <span class="hlt">transport</span> model into a large scale hydrological model: an application in the Amazon basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buarque, D. C.; Collischonn, W.; Paiva, R. C. D.</p> <p>2012-04-01</p> <p>This study presents the first application and preliminary results of the large scale hydrodynamic/hydrological model MGB-IPH with a new module to predict the spatial distribution of the basin erosion and river <span class="hlt">sediment</span> <span class="hlt">transport</span> in a daily time step. The MGB-IPH is a large-scale, distributed and process based hydrological model that uses a catchment based discretization and the Hydrological Response Units (HRU) approach. It uses physical based equations to simulate the hydrological processes, such as the Penman Monteith model for evapotranspiration, and uses the Muskingum Cunge approach and a full 1D hydrodynamic model for river routing; including backwater effects and seasonal flooding. The <span class="hlt">sediment</span> module of the MGB-IPH model is divided into two components: 1) prediction of erosion over the basin and <span class="hlt">sediment</span> yield to river network; 2) <span class="hlt">sediment</span> <span class="hlt">transport</span> along the river channels. Both MGB-IPH and the <span class="hlt">sediment</span> module use GIS tools to display relevant maps and to extract parameters from SRTM DEM (a 15" resolution was adopted). Using the catchment discretization the <span class="hlt">sediment</span> module applies the Modified Universal Soil Loss Equation to predict soil loss from each HRU considering three <span class="hlt">sediment</span> classes defined according to the soil texture: sand, silt and clay. The effects of topography on soil erosion are estimated by a two-dimensional slope length (LS) factor which using the contributing area approach and a local slope steepness (S), both estimated for each DEM pixel using GIS algorithms. The amount of <span class="hlt">sediment</span> releasing to the catchment river reach in each day is calculated using a linear reservoir. Once the <span class="hlt">sediment</span> reaches the river they are <span class="hlt">transported</span> into the river channel using an advection equation for silt and clay and a <span class="hlt">sediment</span> continuity equation for sand. A <span class="hlt">sediment</span> balance based on the Yang <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity, allowing to compute the amount of erosion and deposition along the rivers, is performed for sand particles as <span class="hlt">bed</span> <span class="hlt">load</span>, whilst no</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP21D1875D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP21D1875D"><span>Unravelling the relative contribution of bed and suspended <span class="hlt">sediment</span> load on a large alluvial river</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darby, S. E.; Hackney, C. R.; Parsons, D. R.; Leyland, J.; Aalto, R. E.; Nicholas, A. P.; Best, J.</p> <p>2017-12-01</p> <p>The world's largest rivers <span class="hlt">transport</span> 19 billion tonnes of <span class="hlt">sediment</span> to the coastal zone annually, often supporting large deltas that rely on this <span class="hlt">sediment</span> load to maintain their elevation in the face of rising sea level, and to sustain high levels of agricultural productivity and biodiversity. However, the majority of estimates of <span class="hlt">sediment</span> delivery to coastal regions pertain solely to the suspended fraction of the <span class="hlt">sediment</span> load, with the bedload fraction often being neglected due to the difficulty in estimating bedload flux and the assumption that bedload contributes a minor (<10%) fraction of the total <span class="hlt">sediment</span> load. In large rivers, capturing accurate estimates of the suspended- and <span class="hlt">bed</span>- <span class="hlt">load</span> fractions is difficult given the large channel widths and depths and the intrusive nature of typical methodologies. Yet, for the successful implementation of sustainable river, and delta, management plans, improved estimates of all fractions of the <span class="hlt">sediment</span> load are essential. Recent advances in non-intrusive, high-resolution, technology have begun to enable more accurate estimates of bedload <span class="hlt">transport</span> rates. However, the characterisation of the holistic <span class="hlt">sediment</span> <span class="hlt">transport</span> regime of large alluvial rivers is still lacking. Here, we develop a <span class="hlt">sediment</span> <span class="hlt">transport</span> rating curve, combining both suspended- and <span class="hlt">bed</span>- <span class="hlt">load</span> <span class="hlt">sediment</span> fractions, for the Lower Mekong River. We define suspended <span class="hlt">sediment</span> rating curves using the inversion of acoustic return data from a series of acoustic Doppler current profiler surveys conducted through the Lower Mekong River in Cambodia, and into the bifurcating channels of the Mekong delta in Vietnam. Additionally, we detail estimates of <span class="hlt">bed-load</span> <span class="hlt">sediment</span> <span class="hlt">transport</span> determined using repeat multibeam echo sounder surveys of the channel bed. By combining estimates of both fractions of the <span class="hlt">sediment</span> load, we show the spatial and temporal contribution of bedload to the total <span class="hlt">sediment</span> load of the Mekong and refine estimates of <span class="hlt">sediment</span> <span class="hlt">transport</span> to the Mekong</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1919354V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1919354V"><span>Consistency between 2D-3D <span class="hlt">Sediment</span> <span class="hlt">Transport</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villaret, Catherine; Jodeau, Magali</p> <p>2017-04-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> models have been developed and applied by the engineering community to estimate <span class="hlt">transport</span> rates and morphodynamic bed evolutions in river flows, coastal and estuarine conditions. Environmental modelling systems like the open-source Telemac modelling system include a hierarchy of models from 1D (Mascaret), 2D (Telemac-2D/Sisyphe) and 3D (Telemac-3D/Sedi-3D) and include a wide range of processes to represent <span class="hlt">sediment</span> flow interactions under more and more complex situations (cohesive, non-cohesive and mixed <span class="hlt">sediment</span>). Despite some tremendous progresses in the numerical techniques and computing resources, the quality/accuracy of model results mainly depend on the numerous choices and skills of the modeler. In complex situations involving stratification effects, complex geometry, recirculating flows… 2D model assumptions are no longer valid. A full 3D turbulent flow model is then required in order to capture the vertical mixing processes and to represent accurately the coupled flow/<span class="hlt">sediment</span> distribution. However a number of theoretical and numerical difficulties arise when dealing with <span class="hlt">sediment</span> <span class="hlt">transport</span> modelling in 3D which will be high-lighted : (1) Dependency of model results to the vertical grid refinement and choice of boundary conditions and numerical scheme (2) The choice of turbulence model determines also the <span class="hlt">sediment</span> vertical distribution which is governed by a balance between the downward settling term and upward turbulent diffusion. (3) The use of different numerical schemes for both hydrodynamics (mean and turbulent flow) and <span class="hlt">sediment</span> <span class="hlt">transport</span> modelling can lead to some inconsistency including a mismatch in the definition of numerical cells and definition of boundary conditions. We discuss here those present issues and present some detailed comparison between 2D and 3D simulations on a set of validation test cases which are available in the Telemac 7.2 release using both cohesive and non-cohesive <span class="hlt">sediments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983ECSS...17..547A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983ECSS...17..547A"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> by fishes in Harrington Sound, Bermuda</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alheit, Jürgen</p> <p>1983-11-01</p> <p>Harrington Sound, Bermuda, is a shallow subtropical lagoon with carbonate <span class="hlt">sediments</span>. The most important fishes in this lagoon, in terms of biomass, are grunts (Haemulon aurolineatum, H. flavolineatum, H. sciurus) and a sea-bream (Diplodus bermudensis). These undertake diel feeding migrations from the shallow rocky zone towards the deeper sand and mud zones. When feeding on zoobenthos they cannot avoid swallowing carbonate <span class="hlt">sediment</span> particles. These <span class="hlt">sediment</span> particles pass through the alimentary canal of the fishes and are deposited again, after digestion of the food, as faeces in the shallow zones. Thus, the fishes <span class="hlt">transport</span> the <span class="hlt">sediment</span> in an unusual direction, from the deep to the shallow zones, in effect against the force of gravity. By recording the fish stock densities, digestion rates, and calcium carbonate content of fish stomach and guts, it was possible to estimate the amount of <span class="hlt">sediment</span> <span class="hlt">transported</span> by the fishes. In Harrington Sound, this amounts annually to 4530 kg calcium carbonate, 40% of which is deposited in the very shallow areas. The pH-values measured in fish stomachs seem to be acidic enough for the dissolution of carbonate <span class="hlt">sediment</span> particles when <span class="hlt">transported</span> by fishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHyd..552..366A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHyd..552..366A"><span>Harmonize input selection for <span class="hlt">sediment</span> <span class="hlt">transport</span> prediction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Afan, Haitham Abdulmohsin; Keshtegar, Behrooz; Mohtar, Wan Hanna Melini Wan; El-Shafie, Ahmed</p> <p>2017-09-01</p> <p>In this paper, three modeling approaches using a Neural Network (NN), Response Surface Method (RSM) and response surface method basis Global Harmony Search (GHS) are applied to predict the daily time series suspended <span class="hlt">sediment</span> load. Generally, the input variables for forecasting the suspended <span class="hlt">sediment</span> load are manually selected based on the maximum correlations of input variables in the modeling approaches based on NN and RSM. The RSM is improved to select the input variables by using the errors terms of training data based on the GHS, namely as response surface method and global harmony search (RSM-GHS) modeling method. The second-order polynomial function with cross terms is applied to calibrate the time series suspended <span class="hlt">sediment</span> load with three, four and five input variables in the proposed RSM-GHS. The linear, square and cross corrections of twenty input variables of antecedent values of suspended <span class="hlt">sediment</span> load and water discharge are investigated to achieve the best predictions of the RSM based on the GHS method. The performances of the NN, RSM and proposed RSM-GHS including both accuracy and simplicity are compared through several comparative predicted and error statistics. The results illustrated that the proposed RSM-GHS is as uncomplicated as the RSM but performed better, where fewer errors and better correlation was observed (R = 0.95, MAE = 18.09 (ton/day), RMSE = 25.16 (ton/day)) compared to the ANN (R = 0.91, MAE = 20.17 (ton/day), RMSE = 33.09 (ton/day)) and RSM (R = 0.91, MAE = 20.06 (ton/day), RMSE = 31.92 (ton/day)) for all types of input variables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70121355','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70121355"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> simulation in an armoured stream</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Milhous, Robert T.; Bradley, Jeffrey B.; Loeffler, Cindy L.</p> <p>1986-01-01</p> <p>Improved methods of calculating bed material stability and <span class="hlt">transport</span> must be developed for a gravel bed stream having an armoured surface in order to use the HEC-6 model to examine channel change. Good possibilities exist for use of a two layer model based on the Schoklitsch and the Einstein-Brown <span class="hlt">transport</span> equations. In Einstein-Brown the D35 of the armour is used for stabilities and the D50 of the bed (sub-surface) is used for <span class="hlt">transport</span>. Data on the armour and sub-surface size distribution needs to be obtained as part of a bed material study in a gravel bed river; a "shovel" sample is not adequate. The Meyer-Peter, Muller equation should not be applied to a gravel bed stream with an armoured surface to estimate the initiation of <span class="hlt">transport</span> or for calculation of <span class="hlt">transport</span> at low effective bed shear stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70027092','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70027092"><span>Effects of wave shape on sheet flow <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hsu, T.-J.; Hanes, D.M.</p> <p>2004-01-01</p> <p>A two-phase model is implemented to study the effects of wave shape on the <span class="hlt">transport</span> of coarse-grained <span class="hlt">sediment</span> in the sheet flow regime. The model is based on balance equations for the average mass, momentum, and fluctuation energy for both the fluid and <span class="hlt">sediment</span> phases. Model simulations indicate that the responses of the sheet flow, such as the velocity profiles, the instantaneous bed shear stress, the <span class="hlt">sediment</span> flux, and the total amount of the mobilized <span class="hlt">sediment</span>, cannot be fully parameterized by quasi-steady free-stream velocity and may be correlated with the magnitude of local horizontal pressure gradient (or free-stream acceleration). A net <span class="hlt">sediment</span> flux in the direction of wave advance is obtained for both skewed and saw-tooth wave shapes typical of shoaled and breaking waves. The model further suggests that at critical values of the horizontal pressure gradient, there is a failure event within the bed that mobilizes more <span class="hlt">sediment</span> into the mobile sheet and enhances the <span class="hlt">sediment</span> flux. Preliminary attempts to parameterize the total bed shear stress and the total <span class="hlt">sediment</span> flux appear promising. Copyright 2004 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70182274','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70182274"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> in the presence of large reef bottom roughness</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pomeroy, Andrew; Lowe, Ryan J.; Ghisalberti, Marco; Storlazzi, Curt; Symonds, Graham; Roelvink, Dano</p> <p>2017-01-01</p> <p>The presence of large bottom roughness, such as that formed by benthic organisms on coral reef flats, has important implications for the size, concentration, and <span class="hlt">transport</span> of suspended <span class="hlt">sediment</span> in coastal environments. A 3 week field study was conducted in approximately 1.5 m water depth on the reef flat at Ningaloo Reef, Western Australia, to quantify the cross-reef hydrodynamics and suspended <span class="hlt">sediment</span> dynamics over the large bottom roughness (∼20–40 cm) at the site. A logarithmic mean current profile consistently developed above the height of the roughness; however, the flow was substantially reduced below the height of the roughness (canopy region). Shear velocities inferred from the logarithmic profile and Reynolds stresses measured at the top of the roughness, which are traditionally used in predictive <span class="hlt">sediment</span> <span class="hlt">transport</span> formulations, were similar but much larger than that required to suspend the relatively coarse <span class="hlt">sediment</span> present at the bed. Importantly, these stresses did not represent the stresses imparted on the <span class="hlt">sediment</span> measured in suspension and are therefore not relevant to the description of suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in systems with large bottom roughness. Estimates of the bed shear stresses that accounted for the reduced near-bed flow in the presence of large roughness vastly improved the relationship between the predicted and observed grain sizes that were in suspension. Thus, the impact of roughness, not only on the overlying flow but also on bed stresses, must be accounted for to accurately estimate suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in regions with large bottom roughness, a common feature of many shallow coastal ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OcDyn..66.1285R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OcDyn..66.1285R"><span>Parameterization of wind turbine impacts on hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rivier, Aurélie; Bennis, Anne-Claire; Pinon, Grégory; Magar, Vanesa; Gross, Markus</p> <p>2016-10-01</p> <p>Monopile foundations of offshore wind turbines modify the hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> at local and regional scales. The aim of this work is to assess these modifications and to parameterize them in a regional model. In the present study, this is achieved through a regional circulation model, coupled with a <span class="hlt">sediment</span> <span class="hlt">transport</span> module, using two approaches. One approach is to explicitly model the monopiles in the mesh as dry cells, and the other is to parameterize them by adding a drag force term to the momentum and turbulence equations. Idealised cases are run using hydrodynamical conditions and <span class="hlt">sediment</span> grain sizes typical from the area located off Courseulles-sur-Mer (Normandy, France), where an offshore windfarm is under planning, to assess the capacity of the model to reproduce the effect of the monopile on the environment. Then, the model is applied to a real configuration on an area including the future offshore windfarm of Courseulles-sur-Mer. Four monopiles are represented in the model using both approaches, and modifications of the hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> are assessed over a tidal cycle. In relation to local hydrodynamic effects, it is observed that currents increase at the side of the monopile and decrease in front of and downstream of the monopile. In relation to <span class="hlt">sediment</span> <span class="hlt">transport</span> effect, the results show that resuspension and erosion occur around the monopile in locations where the current speed increases due to the monopile presence, and <span class="hlt">sediments</span> deposit downstream where the bed shear stress is lower. During the tidal cycle, wakes downstream of the monopile reach the following monopile and modify the velocity magnitude and suspended <span class="hlt">sediment</span> concentration patterns around the second monopile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.H52A1158D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.H52A1158D"><span>Development of a <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Component for DHSVM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doten, C. O.; Bowling, L. C.; Maurer, E. P.; Voisin, N.; Lettenmaier, D. P.</p> <p>2003-12-01</p> <p>The effect of forest management and disturbance on aquatic resources is a problem of considerable, contemporary, scientific and public concern in the West. <span class="hlt">Sediment</span> generation is one of the factors linking land surface conditions with aquatic systems, with implications for fisheries protection and enhancement. Better predictive techniques that allow assessment of the effects of fire and logging, in particular, on <span class="hlt">sediment</span> <span class="hlt">transport</span> could help to provide a more scientific basis for the management of forests in the West. We describe the development of a <span class="hlt">sediment</span> <span class="hlt">transport</span> component for the Distributed Hydrology Soil Vegetation Model (DHSVM), a spatially distributed hydrologic model that was developed specifically for assessment of the hydrologic consequences of forest management. The <span class="hlt">sediment</span> <span class="hlt">transport</span> module extends the hydrologic dynamics of DHSVM to predict <span class="hlt">sediment</span> generation in response to dynamic meteorological inputs and hydrologic conditions via mass wasting and surface erosion from forest roads and hillslopes. The mass wasting component builds on existing stochastic slope stability models, by incorporating distributed basin hydrology (from DHSVM), and post-failure, rule-based redistribution of <span class="hlt">sediment</span> downslope. The stochastic nature of the mass wasting component allows specification of probability distributions that describe the spatial variability of soil and vegetation characteristics used in the infinite slope model. The forest roads and hillslope surface erosion algorithms account for erosion from rain drop impact and overland erosion. A simple routing scheme is used to <span class="hlt">transport</span> eroded <span class="hlt">sediment</span> from mass wasting and forest roads surface erosion that reaches the channel system to the basin outlet. A sensitivity analysis of the model input parameters and forest cover conditions is described for the Little Wenatchee River basin in the northeastern Washington Cascades.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26ES...55a2007I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26ES...55a2007I"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Model In Sayung District, Demak</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ismanto, Aris; Zainuri, Muhammad; Hutabarat, Sahala; Nugroho Sugianto, Denny; Widada, Sugeng; Wirasatriya, Anindya</p> <p>2017-02-01</p> <p>Demak has 34,1 km coastline and located in 6043‧26″ - 7009‧43″ South Latitude and 110027‧58″ - 110048‧47″ East Longitude. In the last few years rapid shoreline and erosion has threatened Demak coastal area. No less than 3000 villages on Java suffer similar problems. Hard structures such as dykes and breakwaters is one of the method that is commonly used to solve this problem. However, this method may fail to provide adequate protection to the environment and become counterproductive. One of the alternative to solve the problem is using hybrid engineering concept. This study aims is to assess the distribution model of the <span class="hlt">sediment</span> on the application of technology as a hybrid structure for the mitigationand rehabilitation of coastal areas in Demak. This research using quantitative method, including field surveys and mathematical modeling methods. The model show that the <span class="hlt">sedimention</span> is quite big in highest flood condition and must have the right structure for the hybrid engineering. This study is expected to answer the question of the erosion problem in the District Sayung, Demak.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA455449','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA455449"><span>Longshore <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Rate Calculated Incorporating Wave Orbital Velocity Fluctuations</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2006-09-01</p> <p>distribution of longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> in the surf zone is necessary in the design and planning of groins, jetties, weirs and pipeline landfalls...<span class="hlt">transported</span> by any current. Breaker height is defined as the vertical distance between the wave crest and the preceding wave trough at incipient...terminology; spilling breakers occur if the wave crest becomes unstable and flows down the front face of the wave producing a foamy water surface; plunging</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030110','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030110"><span>Suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in an ephemeral stream following wildfire</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Malmon, D.V.; Reneau, Steven L.; Katzman, D.; Lavine, A.; Lyman, J.</p> <p>2007-01-01</p> <p>We examine the impacts of a stand-clearing wildfire on the characteristics and magnitude of suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in ephemeral streams draining the burn area. We report the results of a monitoring program that includes 2 years of data prior to the Cerro Grande fire in New Mexico, and 3 years of postfire data. Suspended <span class="hlt">sediment</span> concentration (SSC) increased by about 2 orders of magnitude following the fire, and the proportion of silt and clay increased from 50% to 80%. For a given flow event, SSC is highest at the flood bore and decreases monotonically with time, a pattern evident in every flood sampled both before and after the fire. We propose that the accumulation of flow and wash load at the flow front is an inherent characteristic of ephemeral stream flows, due to amplified momentum losses at the flood bore. We present a new model for computing suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in ephemeral streams (in the presence or absence of wildfire) by relating SSC to the time following the arrival of the flood bore, rather than to instantaneous discharge. Using this model and a rainfall history, we estimate that in the 3 years following the fire, floods <span class="hlt">transported</span> in suspension a mass equivalent to about 3 mm of landscape lowering across the burn area, 20% of this following a single rainstorm. We test the model by computing fine <span class="hlt">sediment</span> delivery to a small reservoir in an adjacent watershed, where we have a detailed record of postfire <span class="hlt">sedimentation</span> based on repeat surveys. Systematic discrepancies between modeled and measured <span class="hlt">sedimentation</span> rates in the reservoir suggest rapid reductions in suspended <span class="hlt">sediment</span> delivery in the first several years after the fire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.U51A0005C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.U51A0005C"><span><span class="hlt">Sediment</span> Buffering and <span class="hlt">Transport</span> in the Holocene Indus River System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clift, P. D.; Giosan, L.; Henstock, T.; Tabrez, A. R.; Vanlaningham, S.; Alizai, A. H.; Limmer, D. R.; Danish, M.</p> <p>2009-12-01</p> <p>Submarine fans are the largest <span class="hlt">sediment</span> bodies on Earth and potentially hold records of erosion that could be used to assess the response of continents to changing climate in terms of both physical erosion and chemical weathering. However, buffering between the mountain sources and the abyssal plain may make detailed correlation of climate and erosion records difficult. We investigated the nature of <span class="hlt">sediment</span> <span class="hlt">transport</span> in the Indus drainage in SW Asia. Through trenching in the flood plain, drilling in the delta and new seismic and coring data from the shelf and canyon we can now constrain <span class="hlt">sediment</span> <span class="hlt">transport</span> from source to sink since the Last Glacial Maximum (LGM). The Indus was affected by intensification of the summer monsoon during the Early Holocene and subsequent weakening since ca. 8 ka. <span class="hlt">Sediment</span> delivery to the delta was very rapid at 12-8 ka, but slowed along with the weakening monsoon. At the LGM erosion in the Karakoram dominated the supply of sandy material, while the proportion of Lesser Himalayan flux increased with strengthening summer rainfall after 12 ka. Total load also increased at that time. Since 5 ka incision of rivers into the upper parts of the flood plain has reworked Lower Holocene <span class="hlt">sediments</span>, although the total flux slowed. Coring in the Indus canyon shows that <span class="hlt">sediment</span> has not reached the lower canyon since ca. 7 ka, but that <span class="hlt">sedimentation</span> has recently been very rapid in the head of the canyon. We conclude that variations in sealevel and terrestrial climate have introduced a lag of at least 7 k.y. into the deep sea fan record and that monsoon strength is a primary control on whether <span class="hlt">sediment</span> is stored or released in the flood plain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70195617','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70195617"><span>Quantifying postfire aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> using rare earth element tracers</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dukes, David; Gonzales, Howell B.; Ravi, Sujith; Grandstaff, David E.; Van Pelt, R. Scott; Li, Junran; Wang, Guan; Sankey, Joel B.</p> <p>2018-01-01</p> <p>Grasslands, which provide fundamental ecosystem services in many arid and semiarid regions of the world, are undergoing rapid increases in fire activity and are highly susceptible to postfire-accelerated soil erosion by wind. A quantitative assessment of physical processes that integrates fire-wind erosion feedbacks is therefore needed relative to vegetation change, soil biogeochemical cycling, air quality, and landscape evolution. We investigated the applicability of a novel tracer technique—the use of multiple rare earth elements (REE)—to quantify soil <span class="hlt">transport</span> by wind and to identify sources and sinks of wind-blown <span class="hlt">sediments</span> in both burned and unburned shrub-grass transition zone in the Chihuahuan Desert, NM, USA. Results indicate that the horizontal mass flux of wind-borne <span class="hlt">sediment</span> increased approximately threefold following the fire. The REE tracer analysis of wind-borne <span class="hlt">sediments</span> shows that the source of the horizontal mass flux in the unburned site was derived from bare microsites (88.5%), while in the burned site it was primarily sourced from shrub (42.3%) and bare (39.1%) microsites. Vegetated microsites which were predominantly sinks of aeolian <span class="hlt">sediments</span> in the unburned areas became <span class="hlt">sediment</span> sources following the fire. The burned areas showed a spatial homogenization of <span class="hlt">sediment</span> tracers, highlighting a potential negative feedback on landscape heterogeneity induced by shrub encroachment into grasslands. Though fires are known to increase aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span>, accompanying changes in the sources and sinks of wind-borne <span class="hlt">sediments</span> may influence biogeochemical cycling and land degradation dynamics. Furthermore, our experiment demonstrated that REEs can be used as reliable tracers for field-scale aeolian studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/24500','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/24500"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and channel morphology of small, forested streams.</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Marwan A. Hassan; Michael Church; Thomas E. Lisle; Francesco Brardinoni; Lee Benda; Gordon E. Grant</p> <p>2005-01-01</p> <p>This paper reviews <span class="hlt">sediment</span> <span class="hlt">transport</span> and channel morphology in small, forested streams in the Pacific Northwest region of North America to assess current knowledge of channel stability and morphology relevant to riparian management practices around small streams. Small channels are defined as ones in which morphology and hydraulics may be significantly influenced by...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA516226','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA516226"><span>Planning for a National Community <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Model</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2002-01-01</p> <p>modeling project. The workshop did not develop a NOPP proposal because NOPP had not yet announced funding opportunities for a coastal community modeling...2002, titled “NOPP / USGS Coastal Community <span class="hlt">Sediment-Transport</span> Model”. Dr. Sherwood presented status reports at the NOPP Nearshore Annual meeting in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1005552','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1005552"><span>Mechanisms of <span class="hlt">Sediment</span> Entrainment and <span class="hlt">Transport</span> in Rotorcraft Brownout</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-01-01</p> <p>understanding of the temporal evolution of the rotor wake in ground effect simultaneously with the processes of <span class="hlt">sediment</span> entrainment and <span class="hlt">transport</span> by the rotor ...14 1.8 Schematic and smoke flow visualization of a rotor flow during out-of- ground- effect ...operations. . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.9 Schematic and smoke flow visualization of a rotor flow during in-ground- effect</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMOS31A1699B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMOS31A1699B"><span>Interactive 4D Visualization of <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butkiewicz, T.; Englert, C. M.</p> <p>2013-12-01</p> <p>Coastal <span class="hlt">sediment</span> <span class="hlt">transport</span> models simulate the effects that waves, currents, and tides have on near-shore bathymetry and features such as beaches and barrier islands. Understanding these dynamic processes is integral to the study of coastline stability, beach erosion, and environmental contamination. Furthermore, analyzing the results of these simulations is a critical task in the design, placement, and engineering of coastal structures such as seawalls, jetties, support pilings for wind turbines, etc. Despite the importance of these models, there is a lack of available visualization software that allows users to explore and perform analysis on these datasets in an intuitive and effective manner. Existing visualization interfaces for these datasets often present only one variable at a time, using two dimensional plan or cross-sectional views. These visual restrictions limit the ability to observe the contents in the proper overall context, both in spatial and multi-dimensional terms. To improve upon these limitations, we use 3D rendering and particle system based illustration techniques to show water column/flow data across all depths simultaneously. We can also encode multiple variables across different perceptual channels (color, texture, motion, etc.) to enrich surfaces with multi-dimensional information. Interactive tools are provided, which can be used to explore the dataset and find regions-of-interest for further investigation. Our visualization package provides an intuitive 4D (3D, time-varying) visualization of <span class="hlt">sediment</span> <span class="hlt">transport</span> model output. In addition, we are also integrating real world observations with the simulated data to support analysis of the impact from major <span class="hlt">sediment</span> <span class="hlt">transport</span> events. In particular, we have been focusing on the effects of Superstorm Sandy on the Redbird Artificial Reef Site, offshore of Delaware Bay. Based on our pre- and post-storm high-resolution sonar surveys, there has significant scour and bedform migration around the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031219','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031219"><span>Measuring <span class="hlt">bed</span> <span class="hlt">load</span> discharge in rivers: bedload-surrogate monitoring workshop Minneapolis, Minnesota, 11-14 April 2007</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gray, John R.; Laronne, Jonathan B.; Marr, Jeffrey D.G.</p> <p>2007-01-01</p> <p>The International Bedload-Surrogate Monitoring Workshop (http://www.nced.umn.edu/BRIC_2007.html), organized by the Bedload Research International Cooperative (BRIC; www.bedloadresearch.org), was held to assess and abet progress in continuous, semiautomated, or fully automated (surrogate) technologies for monitoring <span class="hlt">bed</span> <span class="hlt">load</span> discharge in gravel-, sand-, and mixed gravel-sand-bedded rivers. Direct <span class="hlt">bed</span> <span class="hlt">load</span> measurements, particularly at medium and high flows, during which most <span class="hlt">bed</span> <span class="hlt">load</span> occurs, tend to be time-consuming, expensive, and potentially hazardous. Surrogate technologies developed largely over the past decade and used at a number of research sites around the world show considerable promise toward providing relatively dense, robust, and quantifiably reliable <span class="hlt">bed</span> <span class="hlt">load</span> data sets. However, information on the efficacy of selected technologies for use in monitoring programs is needed, as is identification of the ways and means for bringing the most promising and practical of the technologies to fruition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018668','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018668"><span>Observations of <span class="hlt">sediment</span> <span class="hlt">transport</span> on the Amazon subaqueous delta</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sternberg, R.W.; Cacchione, D.A.; Paulson, B.; Kineke, G.C.; Drake, D.E.</p> <p>1996-01-01</p> <p>A 19-day time series of fluid, flow, and suspended-<span class="hlt">sediment</span> characteristics in the benthic boundary layer is analyzed to identify major sedimentary processes active over the prodelta region of the Amazon subaqueous delta. Measurements were made by the benthic tripod GEOPROBE placed on the seabed in 65 m depth near the base of the deltaic foreset beds from 11 February to 3 March 1990, during the time of rising water and maximum <span class="hlt">sediment</span> discharge of the Amazon River; and the observations included: hourly measurements of velocity and suspended-<span class="hlt">sediment</span> concentration at four levels above the seabed; waves and tides; and seabed elevation. Results of the first 14-day period of the time series record indicate that <span class="hlt">sediment</span> resuspension occurred as a result of tidal currents (91% of the time) and surface gravity waves (46% of the time). Observations of suspended <span class="hlt">sediment</span> indicated that particle flux in this region is 0.4-2% of the flux measured on the adjacent topset deposits and is directed to the north and landward relative to the Brazilian coast (268??T). Fortnightly variability is strong, with particle fluxes during spring tides five times greater than during neap tides. On the 15th day of the data record, a rapid <span class="hlt">sedimentation</span> event was documented in which 44 cm of <span class="hlt">sediment</span> was deposited at the study site over a 14-h period. Evaluation of various mechanisms of mass <span class="hlt">sediment</span> movement suggests that this event represents downslope migration of fluid muds from the upper foreset beds that were set in motion by boundary shear stresses generated by waves and currents. This <span class="hlt">transport</span> mechanism appears to occur episodically and may represent a major source of <span class="hlt">sediment</span> to the lower foreset-bottomset region of the subaqueous delta.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6888345-role-naturally-occurring-gas-hydrates-sediment-transport','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6888345-role-naturally-occurring-gas-hydrates-sediment-transport"><span>Role of naturally occurring gas hydrates in <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McIver, R.D.</p> <p>1982-06-01</p> <p>Naturally occurring gas hydrates have the potential to store enormous volumes of both gas and water in semi-solid form in ocean-bottom <span class="hlt">sediments</span> and then to release that gas and water when the hydrate's equilibrium condition are disturbed. Therefore, hydrates provide a potential mechanism for <span class="hlt">transporting</span> large volumes of <span class="hlt">sediments</span>. Under the combined low bottom-water temperatures and moderate hydrostatic pressures that exist over most of the continental slopes and all of the continental rises and abyssal plains, hydrocarbon gases at or near saturation in the interstitial waters of the near-bottom <span class="hlt">sediments</span> will form hydrates. The gas can either be autochthonous, microbiallymore » produced gas, or allochthonous, catagenic gas from deeper <span class="hlt">sediments</span>. Equilibrium conditions that stabilize hydrated <span class="hlt">sediments</span> may be disturbed, for example, by continued <span class="hlt">sedimentation</span> or by lowering of sea level. In either case, some of the solid gas-water matrix decomposes. Released gas and water volume exceeds the volume occupied by the hydrate, so the internal pressure rises - drastically if large volumes of hydrate are decomposed. Part of the once rigid <span class="hlt">sediment</span> is converted to a gas- and water-rich, relatively low density mud. When the internal pressure, due to the presence of the compressed gas or to buoyancy, is sufficiently high, the overlying <span class="hlt">sediment</span> may be lifted and/or breached, and the less dense, gas-cut mud may break through. Such hydrate-related phenomena can cause mud diapirs, mud volcanos, mud slides, or turbidite flows, depending on <span class="hlt">sediment</span> configuration and bottom topography. 4 figures.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdWR..115...17Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdWR..115...17Z"><span>Entrainment, <span class="hlt">transport</span> and deposition of <span class="hlt">sediment</span> by saline gravity currents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zordan, Jessica; Juez, Carmelo; Schleiss, Anton J.; Franca, Mário J.</p> <p>2018-05-01</p> <p>Few studies have addressed simultaneously the feedback between the hydrodynamics of a gravity current and the geomorphological changes of a mobile bed. Hydrodynamic quantities such as turbulent and mean velocities, bed shear stress and turbulent stresses undoubtedly govern the processes of entrainment, <span class="hlt">transport</span> and deposition. On the other hand, the incorporation of entrained <span class="hlt">sediment</span> in the current may change its momentum by introducing extra internal stresses, introducing thus a feedback process. These two main questions are here investigated. Laboratory experiments of saline gravity currents, produced by lock-exchange, flowing over a mobile bed channel reach, are here reported. Different initial buoyancies of the current in the lock are tested together with three different grain sizes of the non-coherent <span class="hlt">sediment</span> that form the erodible bed. Results from velocity measurements are combined with the visualization of the <span class="hlt">sediment</span> movement in the mobile reach and with post-test topographic and photo surveys of the geomorphology modifications of the channel bed. Mean and turbulent velocities are measured and bed shear stress and Reynolds stresses are estimated. We show that the mean vertical component of the velocity and bed shear stress are highly correlated with the first instants of <span class="hlt">sediment</span> entrainment. Vertical turbulent velocity is similarly related to entrainment, although with lower correlation values, contributing as well to the <span class="hlt">sediment</span> movement. Bed shear stress and Reynolds shear stress measured near the bed are correlated with <span class="hlt">sediment</span> entrainment for longer periods, indicating that these quantities are associated to distal <span class="hlt">transport</span> as well. Geomorphological changes in the mobile bed are strongly related to the impulse caused by the bed shear stress on the <span class="hlt">sediment</span>. On the other hand, we show that the nature of the grain of the mobile bed reach influences the hydrodynamics of the current which means that a feedback mechanisms between both occurs during</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP53F1042D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP53F1042D"><span>Numerical modeling of hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> at diversions: why depth-averaged models are not able to capture the inherent physics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dutta, S.; Tassi, P.; Fischer, P.; Wang, D.; Garcia, M. H.</p> <p>2016-12-01</p> <p>Diversions are a subset of asymmetric bifurcations, where one of the channels after bifurcation continues along the direction of the original channel, often referred to as the main-channel. Diversions are not only built for river-engineering purposes, e.g. navigational canals, channels to divert water and <span class="hlt">sediment</span> to rebuild deltas etc.; they can also be formed naturally, e.g. chute cutoffs. Thus correct prediction of the hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> at a diversion is essential. One of the first extensive studies on diversion was conducted by Bulle [1926], where it was found that compared to discharge of water; a disproportionately higher amount of <span class="hlt">bed-load</span> <span class="hlt">sediment</span> entered the lateral-channel at the diversion. Hence, this phenomenon is known as the Bulle-Effect. Recent studies have used high-resolution Large Eddy Simulation (LES) [Dutta et al., 2016a] and Reynolds Averaged Navier-Stokes (RANS) based three-dimensional hydrodynamics model [Dutta et al., 2016b] to unravel the mechanism behind the aforementioned non-linear phenomenon. Such studies have shown that the Bulle-Effect is caused by a stark difference between the flow structure near the bottom of a channel, and near the top of a channel. These findings hint towards the possible failure of 2D shallow water based numerical models in simulating the hydrodynamics and the <span class="hlt">sediment</span> <span class="hlt">transport</span> at a diversion correctly. The current study analyzes the hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> at a 90-degree diversion across five different models of increasing complexity, starting from a 2D depth-averaged hydrodynamics model to a high-resolution LES. This comparative study will provide a clear indication of the minimum amount of complexity a model should inculcate in order to capture the Bulle-Effect relatively well. Bulle, (1926), Untersuchungen ber die geschiebeableitung bei der spaltung von wasserlufen, Technical Report, V.D.I. Verlag, Berlin, Germany Dutta et al., (2016), Large Eddy Simulation (LES) of flow and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.H41G..07J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.H41G..07J"><span>Experimental Bedrock Channel Incision: Scaling, Sculpture and <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, J. P.; Whipple, K. X.</p> <p>2004-12-01</p> <p>Abrasion by <span class="hlt">sediment</span> in turbulent flows often sculpts bedrock channels into dramatic forms; quantifying the feedbacks between fluid flow, <span class="hlt">sediment</span> impacts, and channel morphology is needed to refine models of fluvial incision into bedrock. We present data from laboratory flume experiments funded by the National Center for Earth-Surface Dynamics and conducted at St. Anthony Falls Laboratory, University of Minnesota that show how the spatial and temporal distribution of erosion is strongly coupled to the evolving topography of the bed. These experiments focus on the high Froude number and tool-starved end of parameter space, where bed cover tends to be negligible. Independent variables include flume slope, water flux and <span class="hlt">sediment</span> flux and size distribution. <span class="hlt">Sediment</span> moves energetically as bedload, suspended load, or locally transitional between <span class="hlt">transport</span> modes. Quantitative measurements of the evolving bed topography show that the synthetic brittle "bedrock" in the flume (cured sand-cement mixture) eroded to form narrow incised channels with tight scoops and potholes. The experimental erosional forms are similar in morphology, and sometimes in scale, to those observed in natural bedrock rivers in southeast Utah and other field settings. The experiments demonstrate that both the mean and distribution of measured erosion rates change as the bed topography evolves, even with constant water and <span class="hlt">sediment</span> discharges. Even starting with a plane bed geometry, erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> very quickly become localized in interconnected topographic lows. Positive feedback develops between the evolving topography and the fluid velocity and <span class="hlt">sediment</span> <span class="hlt">transport</span> fields, resulting in the incision of an inner channel. Once formed, the erosion rate in the axis of the inner channel decreases as local bed shear stresses and fluid velocities are reduced by increasing wall drag, and <span class="hlt">sediment</span> fluxes through the channel but causes less incision (no deposition). Decreasing the <span class="hlt">sediment</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017BGeo...14..683B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017BGeo...14..683B"><span>Long-distance electron <span class="hlt">transport</span> occurs globally in marine <span class="hlt">sediments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burdorf, Laurine D. W.; Tramper, Anton; Seitaj, Dorina; Meire, Lorenz; Hidalgo-Martinez, Silvia; Zetsche, Eva-Maria; Boschker, Henricus T. S.; Meysman, Filip J. R.</p> <p>2017-02-01</p> <p>Recently, long filamentous bacteria have been reported conducting electrons over centimetre distances in marine <span class="hlt">sediments</span>. These so-called cable bacteria perform an electrogenic form of sulfur oxidation, whereby long-distance electron <span class="hlt">transport</span> links sulfide oxidation in deeper <span class="hlt">sediment</span> horizons to oxygen reduction in the upper millimetres of the <span class="hlt">sediment</span>. Electrogenic sulfur oxidation exerts a strong impact on the local <span class="hlt">sediment</span> biogeochemistry, but it is currently unknown how prevalent the process is within the seafloor. Here we provide a state-of-the-art assessment of its global distribution by combining new field observations with previous reports from the literature. This synthesis demonstrates that electrogenic sulfur oxidation, and hence microbial long-distance electron <span class="hlt">transport</span>, is a widespread phenomenon in the present-day seafloor. The process is found in coastal <span class="hlt">sediments</span> within different climate zones (off the Netherlands, Greenland, the USA, Australia) and thrives on a range of different coastal habitats (estuaries, salt marshes, mangroves, coastal hypoxic basins, intertidal flats). The combination of a widespread occurrence and a strong local geochemical imprint suggests that electrogenic sulfur oxidation could be an important, and hitherto overlooked, component of the marine cycle of carbon, sulfur and other elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/26823','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/26823"><span>A coupled upland-erosion and instream hydrodynamic-<span class="hlt">sediment</span> <span class="hlt">transport</span> model for evaluating <span class="hlt">sediment</span> <span class="hlt">transport</span> in forested watersheds</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>W. J. Conroy; R. H. Hotchkiss; W. J. Elliot</p> <p>2006-01-01</p> <p>This article describes a prototype modeling system for assessing forest management-related erosion at its source and predicting <span class="hlt">sediment</span> <span class="hlt">transport</span> from hillslopes to stream channels and through channel networks to a watershed outlet. We demonstrate that it is possible to develop a land management tool capable of accurately assessing the primary impacts of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70009691','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70009691"><span>Sudden clearing of estuarine waters upon crossing the threshold from <span class="hlt">transport</span> to supply regulation of <span class="hlt">sediment</span> <span class="hlt">transport</span> as an erodible <span class="hlt">sediment</span> pool is depleted: San Francisco Bay, 1999</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schoellhamer, David H.</p> <p>2011-01-01</p> <p>The quantity of suspended <span class="hlt">sediment</span> in an estuary is regulated either by <span class="hlt">transport</span>, where energy or time needed to suspend <span class="hlt">sediment</span> is limiting, or by supply, where the quantity of erodible <span class="hlt">sediment</span> is limiting. This paper presents a hypothesis that suspended-<span class="hlt">sediment</span> concentration (SSC) in estuaries can suddenly decrease when the threshold from <span class="hlt">transport</span> to supply regulation is crossed as an erodible <span class="hlt">sediment</span> pool is depleted. This study was motivated by a statistically significant 36% step decrease in SSC in San Francisco Bay from water years 1991–1998 to 1999–2007. A quantitative conceptual model of an estuary with an erodible <span class="hlt">sediment</span> pool and <span class="hlt">transport</span> or supply regulation of <span class="hlt">sediment</span> <span class="hlt">transport</span> is developed. Model results confirm that, if the regulation threshold was crossed in 1999, SSC would decrease rapidly after water year 1999 as observed. Estuaries with a similar history of a depositional <span class="hlt">sediment</span> pulse followed by erosion may experience sudden clearing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOS.B13A..04A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOS.B13A..04A"><span>Reactive <span class="hlt">transport</span> modeling of nitrogen in Seine River <span class="hlt">sediments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akbarzadeh, Z.; Laverman, A.; Raimonet, M.; Rezanezhad, F.; Van Cappellen, P.</p> <p>2016-02-01</p> <p>Biogeochemical processes in <span class="hlt">sediments</span> have a major impact on the fate and <span class="hlt">transport</span> of nitrogen (N) in river systems. Organic matter decomposition in bottom <span class="hlt">sediments</span> releases inorganic N species back to the stream water, while denitrification, anammox and burial of organic matter remove bioavailable N from the aquatic environment. To simulate N cycling in river <span class="hlt">sediments</span>, a multi-component reactive <span class="hlt">transport</span> model has been developed in MATLAB®. The model includes 3 pools of particulate organic N, plus pore water nitrate, nitrite, nitrous oxide and ammonium. Special attention is given to the production and consumption of nitrite, a N species often neglected in early diagenetic models. Although nitrite is usually considered to be short-lived, elevated nitrite concentrations have been observed in freshwater streams, raising concerns about possible toxic effects. We applied the model to <span class="hlt">sediment</span> data sets collected at two locations in the Seine River, one upstream, the other downstream, of the largest wastewater treatment plant (WWTP) of the Paris conurbation. The model is able to reproduce the key features of the observed pore water depth profiles of the different nitrogen species. The modeling results show that the presence of oxygen in the overlying water plays a major role in controlling the exchanges of nitrite between the <span class="hlt">sediments</span> and the stream water. In August 2012, <span class="hlt">sediments</span> upstream of the WWTP switch from being a sink to a source of nitrite as the overlying water becomes anoxic. Downstream <span class="hlt">sediments</span> remain a nitrite sink in oxic and anoxic conditions. Anoxic bottom waters at the upstream location promote denitrification, which produces nitrite, while at the downstream site, anammox and DNRA are important removal processes of nitrite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H21F1129W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H21F1129W"><span>Quantifying <span class="hlt">Sediment</span> <span class="hlt">Transport</span> in a Premontane Transitional Cloud Forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waring, E. R.; Brumbelow, J. K.</p> <p>2013-12-01</p> <p>Quantifying <span class="hlt">sediment</span> <span class="hlt">transport</span> is a difficult task in any watershed, and relatively little direct measurement has occurred in tropical, mountainous watersheds. The Howler Monkey Watershed (2.2 hectares) is located in a premontane transitional cloud forest in San Isidro de Peñas Blancas, Costa Rica. In June 2012, a V-notch stream-gaging weir was built in the catchment with a 8 ft by 6 ft by 4 ft concrete stilling basin. <span class="hlt">Sediment</span> captured by the weir was left untouched for an 11 month time period. To collect the contents of the weir, the stream was rerouted and the weir was drained. The stilling basin contents were systematically sampled, and samples were taken to a lab and characterized using sieve and hydrometer tests. The wet volume of the remaining <span class="hlt">sediment</span> was obtained, and dry mass was estimated. Particle size distribution of samples were obtained from lab tests, with 96% of <span class="hlt">sediment</span> trapped by the weir being sand or coarser. The efficiency of the weir as a <span class="hlt">sediment</span> collector was evaluated by comparing particle fall velocities to residence time of water in the weir under baseflow conditions. Under these assumptions, only two to three percent of the total mass of soil <span class="hlt">transported</span> in the stream is thought to have been suspended in the water and lost over the V-notch. Data were compared to the Universal Soil Loss Equation (USLE), a widely accepted method for predicting soil loss in agricultural watersheds. As expected, application of the USLE to a tropical rainforest was problematic with uncertainty in parameters yielding a soil loss estimate varying by a factor of 50. Continued monitoring of <span class="hlt">sediment</span> <span class="hlt">transport</span> should yield data for improved methods of soil loss estimation applicable to tropical mountainous forests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CG.....90...24X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CG.....90...24X"><span>Shelf <span class="hlt">sediment</span> <span class="hlt">transport</span> during hurricanes Katrina and Rita</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Kehui; Mickey, Rangley C.; Chen, Qin; Harris, Courtney K.; Hetland, Robert D.; Hu, Kelin; Wang, Jiaze</p> <p>2016-05-01</p> <p>Hurricanes can greatly modify the sedimentary record, but our coastal scientific community has rather limited capability to predict hurricane-induced <span class="hlt">sediment</span> deposition. A three-dimensional <span class="hlt">sediment</span> <span class="hlt">transport</span> model was developed in the Regional Ocean Modeling System (ROMS) to study seabed erosion and deposition on the Louisiana shelf in response to Hurricanes Katrina and Rita in the year 2005. Sensitivity tests were performed on both erosional and depositional processes for a wide range of erosional rates and settling velocities, and uncertainty analysis was done on critical shear stresses using the polynomial chaos approximation method. A total of 22 model runs were performed in sensitivity and uncertainty tests. Estimated maximum erosional depths were sensitive to the inputs, but horizontal erosional patterns seemed to be controlled mainly by hurricane tracks, wave-current combined shear stresses, seabed grain sizes, and shelf bathymetry. During the passage of two hurricanes, local resuspension and deposition dominated the <span class="hlt">sediment</span> <span class="hlt">transport</span> mechanisms. Hurricane Katrina followed a shelf-perpendicular track before making landfall and its energy dissipated rapidly within about 48 h along the eastern Louisiana coast. In contrast, Hurricane Rita followed a more shelf-oblique track and disturbed the seabed extensively during its 84-h passage from the Alabama-Mississippi border to the Louisiana-Texas border. Conditions to either side of Hurricane Rita's storm track differed substantially, with the region to the east having stronger winds, taller waves and thus deeper erosions. This study indicated that major hurricanes can disturb the shelf at centimeter to meter levels. Each of these two hurricanes suspended seabed <span class="hlt">sediment</span> mass that far exceeded the annual <span class="hlt">sediment</span> inputs from the Mississippi and Atchafalaya Rivers, but the net <span class="hlt">transport</span> from shelves to estuaries is yet to be determined. Future studies should focus on the modeling of <span class="hlt">sediment</span> exchange between</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=289471','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?direntryid=289471"><span>Modeling Nitrogen Fate and <span class="hlt">Transport</span> at the <span class="hlt">Sediment</span>-Water ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Diffusive mass transfer at media interfaces exerts control on the fate and <span class="hlt">transport</span> of pollutants originating from agricultural and urban landscapes and affects the con-ditions of water bodies. Diffusion is essentially a physical process affecting the distribution and fate of various environmental pollutants such as nutrients, pesticides, metals, PCBs, PAHs, etc. Environmental problems caused by excessive use of agricultural chemicals (e.g., pesticides and fertilizers) and improper discharge of industrial waste and fuel leaks are all influenced by the diffusive nature of pollutants in the environment. Eutrophication is one such environmental problem where the <span class="hlt">sediment</span>-water interface exerts a significant physical and geochemical control on the eutrophic condition of the stressed water body. Exposure of streams and lakes to contaminated <span class="hlt">sediment</span> is another common environmental problem whereby <span class="hlt">transport</span> of the contaminant (PCBs, PAHs, and other organic contaminants) across the <span class="hlt">sediment</span> water can increase the risk for exposure to the chemicals and pose a significant health hazard to aquatic life and human beings. This chapter presents analytical and numerical models describing fate and <span class="hlt">transport</span> phenomena at the <span class="hlt">sediment</span>-water interface in freshwater ecosystems, with the primary focus on nitrogen cycling and the applicability of the models to real-world environmental problems and challenges faced in their applications. The first model deals with nitrogen cycling</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RSPSA.47360785A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RSPSA.47360785A"><span>Origin of the scaling laws of <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ali, Sk Zeeshan; Dey, Subhasish</p> <p>2017-01-01</p> <p>In this paper, we discover the origin of the scaling laws of <span class="hlt">sediment</span> <span class="hlt">transport</span> under turbulent flow over a <span class="hlt">sediment</span> bed, for the first time, from the perspective of the phenomenological theory of turbulence. The results reveal that for the incipient motion of <span class="hlt">sediment</span> particles, the densimetric Froude number obeys the `(1 + σ)/4' scaling law with the relative roughness (ratio of particle diameter to approach flow depth), where σ is the spectral exponent of turbulent energy spectrum. However, for the bedforms, the densimetric Froude number obeys a `(1 + σ)/6' scaling law with the relative roughness in the enstrophy inertial range and the energy inertial range. For the bedload flux, the bedload <span class="hlt">transport</span> intensity obeys the `3/2' and `(1 + σ)/4' scaling laws with the <span class="hlt">transport</span> stage parameter and the relative roughness, respectively. For the suspended load flux, the non-dimensional suspended <span class="hlt">sediment</span> concentration obeys the `-Z ' scaling law with the non-dimensional vertical distance within the wall shear layer, where Z is the Rouse number. For the scour in contracted streams, the non-dimensional scour depth obeys the `4/(3 - σ)', `-4/(3 - σ)' and `-(1 + σ)/(3 - σ)' scaling laws with the densimetric Froude number, the channel contraction ratio (ratio of contracted channel width to approach channel width) and the relative roughness, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFMOS51A..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFMOS51A..07S"><span>Measurements of <span class="hlt">Sediment</span> <span class="hlt">Transport</span> in the Western Adriatic Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sherwood, C. R.; Hill, P. S.</p> <p>2003-12-01</p> <p>Instrumented bottom tripods were deployed at two depths (10 and 20 m) off the mouth of the Chienti River in the western Adriatic Sea from November 2002 to May 2003 as part of the EuroSTRATAFORM Po and Apennine <span class="hlt">Sediment</span> <span class="hlt">Transport</span> and Accumulation (PASTA) Experiment. Waves, currents, and proxies for suspended-<span class="hlt">sediment</span> concentrations were measured with upward-looking acoustic Doppler current meters, downward looking pulse-coherent acoustic Doppler profilers, single-point acoustic Doppler velocimeters, and acoustic and optical backscatter sensors. Flow was dominated by the western Adriatic coastal current (WACC) during the experiment. Mean southward alongshore velocity 2 m below the surface was 0.10 m/s at the 10-m site and 0.23 m/s at the 20-m site, and flow was modulated by tides, winds, and fluctuating riverflow. The largest waves (3 m significant height) were generated by winds from the southeast during a Sirocco event in late November that generated one of the few episodes of sustained northward flow and <span class="hlt">sediment</span> <span class="hlt">transport</span>. Most of the time, however, <span class="hlt">sediment</span> resuspension and <span class="hlt">transport</span> was dominated by Bora events, when downwelling-favorable winds from the northeast generated waves that resuspended <span class="hlt">sediment</span> and simultaneously enhanced southward flow in the WACC. Mean flow near the bottom was slightly offshore at the 20-m site (0.01 m/s at 3 m above the bottom), but there was no significant correlation between downwelling and wave-induced resuspension, and cross-shelf <span class="hlt">sediment</span> fluxes were small. The combination of persistent southward flow with low rates of cross-shelf leakage makes the WACC an efficient conduit for <span class="hlt">sediment</span> past the Chienti region. If these observations are representative of typical winter conditions along the entire western Adriatic, they may help explain the enigmatic development of Holocene shelf-edge clinoforms that have formed hundreds of kilometers south of the Po River, which provides most of the <span class="hlt">sediment</span> to the Adriatic Sea. Future data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.5856C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.5856C"><span>Longshore <span class="hlt">Sediment</span> <span class="hlt">Transport</span> on a Macrotidal Mixed <span class="hlt">Sediment</span> Beach, Birling Gap, United Kingdom.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curoy, J.; Moses, C. A.; Robinson, D. A.</p> <p>2012-04-01</p> <p>Mixed beaches (MBs), with <span class="hlt">sediment</span> sizes ranging over three orders of magnitude, are an increasingly important coastal defence on > 1/3 of the shoreline of England and Wales. In East Sussex, the combined effect of coastal defence management schemes (extensive groyning and sea wall construction) has reduced beach <span class="hlt">sediment</span> supply. Local authorities counteract the increased flood risk by recycling or artificially recharging beaches on the most vulnerable and populated areas. Beaches lose <span class="hlt">sediment</span> predominantly via longshore <span class="hlt">transport</span> (LST) whose accurate quantification is critical to calculating recharge amounts needed for effective beach management. Industry does this by using <span class="hlt">sediment</span> <span class="hlt">transport</span> modelling which depends on reliable input data and modelling assumptions. To improve understanding of processes and quantification of LST on MBs, this study has accurately measured <span class="hlt">sediment</span> <span class="hlt">transport</span> on a natural, macrotidal, MB. The 1.2 km natural MB at Birling Gap, East Sussex here is located on the downdrift end of an 80 km long sub-sedimentary cell and is oriented WNW-ESE. The beach lies on a low gradient chalk shore platform backed by sub-vertical chalk cliffs. It is composed primarily of flint gravel with a peak grain size distribution of 30 to 50 mm, and a sand content of up to 30%. <span class="hlt">Sediment</span> <span class="hlt">transport</span> was measured using pebble tracers and GPS surface surveys during three survey periods of three to five consecutive days in March, May and December 2006. Tracer pebbles, matching the beach pebbles' D50, were made of an epoxy resin with a copper core allowing their detection and recovery to a depth of 40 cm using a metal detector. Tracers were deployed on the upper, middle and lower beach, from the surface into the beach to depths of up to 40 cm. They were collected on the low tide following deployment. The wave conditions were recorded on a Valeport DWR wave recorder located seaward of the beach on the chalk platform. Over the three study periods a large spectrum of wave</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1911337B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911337B"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> dynamics in steep, tropical volcanic catchments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birkel, Christian; Solano Rivera, Vanessa; Granados Bolaños, Sebastian; Brenes Cambronero, Liz; Sánchez Murillo, Ricardo; Geris, Josie</p> <p>2017-04-01</p> <p>How volcanic landforms in tropical mountainous regions are eroded, and how eroded materials move through these mostly steep landscapes from the headwaters to affect <span class="hlt">sediment</span> fluxes are critical to water resources management in their downstream rivers. Volcanic landscapes are of particular importance because of the short timescales (< years) over which they transform. Owing to volcanism and seismic activity, landslides and other mass movements frequently occur. These processes are amplified by high intensity precipitation inputs resulting in significant, but natural runoff, erosion and <span class="hlt">sediment</span> fluxes. <span class="hlt">Sediment</span> <span class="hlt">transport</span> is also directly linked to carbon and solute export. However, knowledge on the <span class="hlt">sediment</span> sources and <span class="hlt">transport</span> dynamics in the humid tropics remains limited and their fluxes largely unquantified. In order to increase our understanding of the dominant erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> dynamics in humid tropical volcanic landscapes, we conducted an extensive monitoring effort in a pristine and protected (biological reserve Alberto Manuel Brenes, ReBAMB) tropical forest catchment (3.2 km2), located in the Central Volcanic Cordillera of Costa Rica (Figure 1A). Typical for tropical volcanic and montane regions, deeply incised V-form headwaters (Figure 1B) deliver the majority of water (>70%) and <span class="hlt">sediments</span> to downstream rivers. At the catchment outlet (Figure 1C) of the San Lorencito stream, we established high temporal resolution (5min) water quantity and <span class="hlt">sediment</span> monitoring (turbidity). We also surveyed the river network on various occasions to characterize fluvial geomorphology including material properties. We could show that the rainfall-runoff-<span class="hlt">sediment</span> relationships and their characteristic hysteresis patterns are directly linked to variations in the climatic input (storm intensity and duration) and the size, form and mineralogy of the <span class="hlt">transported</span> material. Such a relationship allowed us to gain the following insights: (i) periodic landslides contribute</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70023155','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70023155"><span>Colorado River <span class="hlt">sediment</span> <span class="hlt">transport</span>: 1. Natural <span class="hlt">sediment</span> supply limitation and the influence of Glen Canyon Dam</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Topping, David J.; Rubin, David M.; Vierra, L.E.</p> <p>2000-01-01</p> <p>Analyses of flow, sediment‐<span class="hlt">transport</span>, bed‐topographic, and sedimentologic data suggest that before the closure of Glen Canyon Dam in 1963, the Colorado River in Marble and Grand Canyons was annually supply‐limited with respect to fine <span class="hlt">sediment</span> (i.e., sand and finer material). Furthermore, these analyses suggest that the predam river in Glen Canyon was not supply‐limited to the same degree and that the degree of annual supply limitation increased near the head of Marble Canyon. The predam Colorado River in Grand Canyon displays evidence of four effects of supply limitation: (1) seasonal hysteresis in <span class="hlt">sediment</span> concentration, (2) seasonal hysteresis in <span class="hlt">sediment</span> grain size coupled to the seasonal hysteresis in <span class="hlt">sediment</span> concentration, (3) production of inversely graded flood deposits, and (4∥ development or modification of a lag between the time of a flood peak and the time of either maximum or minimum (depending on reach geometry) bed elevation. Analyses of <span class="hlt">sediment</span> budgets provide additional support for the interpretation that the predam river was annually supply‐limited with respect to fine <span class="hlt">sediment</span>, but it was not supply‐limited with respect to fine <span class="hlt">sediment</span> during all seasons. In the average predam year, sand would accumulate and be stored in Marble Canyon and upper Grand Canyon for 9 months of the year (from July through March) when flows were dominantly below 200–300 m3/s; this stored sand was then eroded during April through June when flows were typically higher. After closure of Glen Canyon Dam, because of the large magnitudes of the uncertainties in the <span class="hlt">sediment</span> budget, no season of substantial sand accumulation is evident. Because most flows in the postdam river exceed 200–300 m3/s, substantial sand accumulation in the postdam river is unlikely.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP33C0999C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP33C0999C"><span>Effect of Vegetation on <span class="hlt">Sediment</span> <span class="hlt">Transport</span> across Salt Marshes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coleman, D. J.; Kirwan, M. L.; Guntenspergen, G. R.; Ganju, N. K.</p> <p>2016-12-01</p> <p>Salt marshes are a classic example of ecogeomorphology where interactions between plants and <span class="hlt">sediment</span> <span class="hlt">transport</span> govern the stability of a rapidly evolving ecosystem. In particular, plants slow water velocities which facilitates deposition of mineral <span class="hlt">sediment</span>, and the resulting change in soil elevation influences the growth and species distribution of plants. The ability of a salt marsh to withstand sea level rise (SLR) is therefore dependent, among other factors, on the availability of mineral <span class="hlt">sediment</span>. Here we measure suspended <span class="hlt">sediment</span> concentrations (SSC) along a transect from tidal channel to marsh interior, exploring the role biomass plays in regulating the magnitude and spatial variability in vertical accretion. Our study was conducted in Spartina alterniflora dominated salt marshes along the Atlantic Coast from Massachusetts to Georgia. At each site, we deployed and calibrated optical back scatter turbidity probes to measure SSC in 15 minute intervals in a tidal channel, on the marsh edge, and in the marsh interior. We visited each site monthly to measure plant biomass via clip plots and vertical accretion via two types of <span class="hlt">sediment</span> tiles. Preliminary results confirm classic observations that biomass is highest at the marsh edge, and that SSC and vertical accretion decrease across the marsh platform with distance from the channel. We expect that when biomass is higher, such as in southern sites like Georgia and months late in the growing season, SSC will decay more rapidly with distance into the marsh. Higher biomass will likely also correspond to increased vertical accretion, with the greatest effect at marsh edge locations. Our study will likely demonstrate how salt marsh plants interact with <span class="hlt">sediment</span> <span class="hlt">transport</span> dynamics to control marsh morphology and thus contribute to marsh resilience to SLR.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC23D1263S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC23D1263S"><span>Modeling <span class="hlt">Sediment</span> <span class="hlt">Transport</span> to the Ganga-Brahmaputra-Meghna Delta</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silvestre, J.; Higgins, S.; Jennings, K. S.</p> <p>2016-12-01</p> <p>India's National River Linking Project (NRLP) will transfer approximately 174 Bm3/y of water from the mountainous, water-rich north to the water-scarce south and west. Although there are many short-term benefits of the NRLP, such as decreased flooding during the monsoon season and increased water resources for irrigation, long-term consequences may include decreased <span class="hlt">sedimentation</span> to the Ganga-Brahmaputra-Meghna Delta (GBM). Currently the GBM has a vertical aggradation rate of approximately 1-2 cm/y and is able to compensate for a global mean sea level rise of 3.3 ± 0.4 mm/y. However, Bangladesh and the GBM stand to be geomorphically impacted should the aggradation rate fall below sea level rise. This study better constrains influences of anthropogenic activities and <span class="hlt">sediment</span> <span class="hlt">transport</span> to the GBM. We employ HydroTrend, a climate-driven hydrological and <span class="hlt">sediment</span> <span class="hlt">transport</span> model, to simulate daily <span class="hlt">sediment</span> and water fluxes for the period 1982 - 2012. Simulations are calibrated and validated against water discharge data from the Farakka Barrage, and different ways of delineating the Ganga Basin into sub-catchments are explored. Preliminary results show a 47% difference between simulated and observed mean annual water discharge when using basin-averaged input values and only a 1% difference for the base-case scenario, where proposed dams and canals are not included. Comparisons between the canals simulation (proposed NRLP included) and validation data suggest a 60% reduction in <span class="hlt">sediment</span> load. However, comparison between the base-case simulation and the canals simulation suggests that India's water transfer project could decrease <span class="hlt">sediment</span> delivery to the GBM by 9%. Further work should investigate improvements in the agreement between base-case simulation and validation data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916014C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916014C"><span>Morphodynamics modelling of bars in channels with graded <span class="hlt">sediment</span> and <span class="hlt">sediment</span> supply variation with the Telemac-Mascaret System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cordier, Florian; Tassi, Pablo; Claude, Nicolas; Crosato, Alessandra; Rodrigues, Stéphane; Pham van Bang, Damien</p> <p>2017-04-01</p> <p>Numerical modelling of graded <span class="hlt">sediment</span> <span class="hlt">transport</span> in rivers remains a challenge [Siviglia and Crosato, 2016] and only few studies have considered the non-uniform distribution of <span class="hlt">sediment</span>, although <span class="hlt">sediment</span> grading is an inherent characteristic of natural rivers. The present work aims at revisiting the morphodynamics module of the Telemac-Mascaret modelling system and to integrate the latest developments to model the effects of non-uniform <span class="hlt">sediment</span> on i) the <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity estimated at the interface between the flow and the riverbed and on ii) the vertical sorting of <span class="hlt">sediment</span> deposits in response to <span class="hlt">sediment</span> supply changes. The implementation of these two processes has a key role on the modelling of bar dynamics in aggrading/degrading channels [Blom, 2008]. Numerical modelling of graded <span class="hlt">sediment</span> <span class="hlt">transport</span> remains a challenge due to the difficulty to reproduce the non-linear interactions between grains of different shape and size. Application of classical bedload equations usually fails in reproducing relevant <span class="hlt">transport</span> rates [Recking, 2010 and references therein]. In this work, the graded <span class="hlt">sediment</span> <span class="hlt">transport</span> model of Wilcock and Crowe [2003] and the active layer concept of Hirano [1971] for the formulation of the exchange layer are implemented. The ability to reproduce the formation and evolution of graded-<span class="hlt">sediment</span> bars is assessed on the basis of laboratory experiences from the literature. References: Blom, A., Ribberink, J. S., and Parker, G. 2008. Vertical sorting and the morphodynamics of bed form-dominated rivers: A sorting evolution model. Journal of Geophysical Research: Earth Surface, 113(F1). Lauer, J. W., Viparelli, E., and Piégay, H. 2016. Morphodynamics and <span class="hlt">sediment</span> tracers in 1-d (mast-1d): 1-d <span class="hlt">sediment</span> <span class="hlt">transport</span> that includes exchange with an off-channel <span class="hlt">sediment</span> reservoir. Advances in Water Resources. Recking, A. 2010. A comparison between flume and field <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> data and consequences for surface-based <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28984430','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28984430"><span>Modeling <span class="hlt">sediment</span> <span class="hlt">transport</span> in Qatar: Application for coastal development planning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yousif, Ruqaiya; Warren, Christopher; Ben-Hamadou, Radhouan; Husrevoglu, Sinan</p> <p>2018-03-01</p> <p>Hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> are key physical processes contributing to habitat structure within the marine environment. Coastal development that results in the alteration of these processes (e.g., changing water flushing and/or <span class="hlt">sedimentation</span> rates) can have detrimental impacts on sensitive systems. This is a current, relevant issue in Qatar as its coastal regions continue to be developed, not only around the capital of Doha, but in many areas around this Arabian Gulf peninsula. The northeastern Qatari coast is comprised of diverse and sensitive flora and fauna such as seagrass and macroalgae meadows, coral reefs and patches, turtles, and dugongs that tolerate harsh environmental conditions. In the near future, this area may see a rise in anthropogenic activity in the form of coastal development projects. These projects will add to existing natural stresses, such as high temperature, high salinity, and low rates of precipitation. Consequently, there is a need to characterize this area and assess the potential impacts that these anthropogenic activities may have on the region. In the present study, a novel <span class="hlt">sediment</span> <span class="hlt">transport</span> model is described and used to demonstrate the potential impact of altering hydrodynamics and subsequent <span class="hlt">sediment</span> <span class="hlt">transport</span> along the northeastern Qatar nearshore marine environment. The developed models will be tested using potential scenarios of future anthropogenic activities forecasted to take place in the area. The results will show the effects on water and <span class="hlt">sediment</span> behavior and provide a scientific approach for key stakeholders to make decisions with respect to the management of the considered coastal zone. Furthermore, it provides a tool and framework that can be utilized in environmental impact assessment and associated hydrodynamic studies along other areas of the Qatari coastal zone. Integr Environ Assess Manag 2018;14:240-251. © 2017 SETAC. © 2017 SETAC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13B1611H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13B1611H"><span>The Influence of Turbulent Coherent Structure on Suspended <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, S. H.; Tsai, C.</p> <p>2017-12-01</p> <p>The anomalous diffusion of turbulent <span class="hlt">sedimentation</span> has received more and more attention in recent years. With the advent of new instruments and technologies, researchers have found that <span class="hlt">sediment</span> behavior may deviate from Fickian assumptions when particles are heavier. In particle-laden flow, bursting phenomena affects instantaneous local concentrations, and seems to carry suspended particles for a longer distance. Instead of the pure diffusion process in an analogy to Brownian motion, Levy flight which allows particles to move in response to bursting phenomena is suspected to be more suitable for describing particle movement in turbulence. And the fractional differential equation is a potential candidate to improve the concentration profile. However, stochastic modeling (the Differential Chapmen-Kolmogorov Equation) also provides an alternative mathematical framework to describe system transits between different states through diffusion/the jump processes. Within this framework, the stochastic particle tracking model linked with advection diffusion equation is a powerful tool to simulate particle locations in the flow field. By including the jump process to this model, a more comprehensive description for suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> can be provided with a better physical insight. This study also shows the adaptability and expandability of the stochastic particle tracking model for suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70189939','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70189939"><span>Mechanics of flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> in delta distributary channels</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nelson, Jonathan M.; Kinzel, Paul J.; Duc Toan, Duong; Shimizu, Yasuyuki; McDonald, Richard R.</p> <p>2011-01-01</p> <p>boundary conditions. Over time, the pattern of erosion and deposition in the distributary channels gives rise to variations in the amount of water and <span class="hlt">sediment</span> routed into them. In the simplest case, this results in channel switching on deltas, but in a more general sense these dynamics produce a rich suite of interesting morphologic change contributing both to the evolution of the channel distributary network and the overall evolution of the delta. As part of a study to develop a better understanding of these processes, we conducted a field study measuring the detailed morphology of the Hong-Luoc junction on the Red River downstream of Hanoi, Vietnam. This junction was selected for such a study because it has a 1,000-year history, modern observations suggest that it is currently switching (changing the proportion of <span class="hlt">sediment</span> and streamflow provided to each of the distributary channels), and hydrologic configuration of the junction allows for the study of two bifurcations and one confluence in a single junction complex. In this paper, our morphologic observations are used in computational flow models to show how flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> changes as a function of total discharge upstream of the junction. This is a key component of understanding how the junction attains stability over a range of flows or how imbalances in the distribution of flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> lead to destabilization of the channel bifurcation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1212157B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1212157B"><span><span class="hlt">Transport</span> phenomena of graded <span class="hlt">sediments</span> in tidal environments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bonaldo, Davide; Dall'Angelo, Chiara; di Silvio, Giampaolo</p> <p>2010-05-01</p> <p>A long-term morphodynamic model simulating the ontogenesis and evolution of a tidal lagoon has been undergoing a continuous improvement in order to enrich its predictive ability and assess the relative importance of different factors, of both natural and anthropogenic origin, in defining the equilibrium configuration of such systems. A significant step forward in this direction is achieved by introducing the possibility to extend the analysis from uniform to graded <span class="hlt">sediments</span>. In the latter case the representation of long-term phenomena is conceptually the same as for a <span class="hlt">sediment</span> characterized by a single granulometric class, as far as it concerns the temporal averaging and the splitting of the <span class="hlt">transport</span> in a dispersive component (mainly given by tidal action) and an eulerian residual convective component (resulting from rivers, long-shore currents, and asymmetry between flood and ebb flow fields). The horizontal <span class="hlt">sediment</span> budget, however, is now coupled with a <span class="hlt">sediment</span> budget among the different granulometric classes in the bottom, and precisely in a "mixing layer" whose thickness has to be properly defined. This new enhancement of the model allows, beside a more precise description of the morphodynamic processes, a certain number of further investigations. As a first point, it makes it possible to study the effect of the initial stratigraphic conditions on the genesis and evolution of the tidal basin, thus obtaining some informations about the persistence of "geological memory" in the system. Another matter, of environmental interest rather than strictly morphodynamic, concerns the possibility of creating "auxiliary classes" among the grainsize classes in order to label and track contaminated <span class="hlt">sediments</span>, providing a prediction tool and a decisional support in case of environmental accidents. Such a <span class="hlt">sediment</span> tracking could also be used to distinguish the <span class="hlt">sediments</span> according to their fluvial or maritime origin, defining in this way a criterion for the classification of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070030054&hterms=Bourke&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBourke','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070030054&hterms=Bourke&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBourke"><span>Aeolian <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Pathways and Aerodynamics at Troughs on Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bourke, Mary C.; Bullard, Joanna E.; Barnouin-Jha, Olivier S.</p> <p>2004-01-01</p> <p>Interaction between wind regimes and topography can give rise to complex suites of aeolian landforms. This paper considers aeolian <span class="hlt">sediment</span> associated wit11 troughs on Mars and identifies a wider range of deposit types than has previously been documented. These include wind streaks, falling dunes, "lateral" dunes, barchan dunes, linear dunes, transverse ridges, sand ramps, climbing dunes, sand streamers, and sand patches. The <span class="hlt">sediment</span> incorporated into these deposits is supplied by wind streaks and ambient Planitia sources as well as originating within the trough itself, notably from the trough walls and floor. There is also transmission of <span class="hlt">sediment</span> between dneTsh. e flow dynamics which account for the distribution of aeolian <span class="hlt">sediment</span> have been modeled using two-dimensional computational fluid dynamics. The model predicts flow separation on the upwind side of the trough followed by reattachment and acceleration at the downwind margin. The inferred patterns of <span class="hlt">sediment</span> <span class="hlt">transport</span> compare well with the distribution of aeolian forms. Model data indicate an increase of wind velocity by approx. 30 % at the downwind trough margin. This suggests that the threshold wind speed necessary for sand mobilization on Mars will be more freqentmlye t in these inclined locations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1993/4067/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1993/4067/report.pdf"><span><span class="hlt">Sediment-transport</span> characteristics of Cane Creek, Lauderdale County, Tennessee</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Carey, W.P.</p> <p>1993-01-01</p> <p>An investigation of the <span class="hlt">sediment-transport</span> characteristics of Cane Creek in Lauderdale County, Tennessee, was conducted from 1985-88 to evaluate the potential for channel erosion induced by modifications (realignment and enlargement) and the potential ability of different flows to move bed and bank stabilizing material. Frequently occurring flows in Cane Creek are capable of moving sand-size material (0.0625 - 4.0 millimeters). During floods that equal or exceed the 2-year flood, Cane Creek is capable of moving very coarse gravel (32 - 64 millimeters). Boundary-shear values at bridges, where flow contractions occur, correspond to critical diameters in excess of 100 millimeters. Thus, the areas near bridges, where channel stability is most critical, are the areas where erosive power is greatest. Deepening and widening of Cane Creek has exposed large areas of channel boundary that are a significant source of raindrop-detached <span class="hlt">sediment</span> during the early stages of a storm before stream flow increases signifi- cantly. This causes suspended-<span class="hlt">sediment</span> concentration to peak while the flow hydrograph is just beginning to rise. For basins like Cane Creek, where runoff events commonly last less than a day and where variation in discharge and <span class="hlt">sediment</span> concentrations are large, an estimate of <span class="hlt">sediment</span> yield based on periodic observations of instantaneous values is subject to considerable uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1112254L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1112254L"><span>Abrasion and Fragmentation Processes in Marly <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Le Bouteiller, C.; Naaim, F.; Mathys, N.; Lave, J.; Kaitna, R.</p> <p>2009-04-01</p> <p>In the highly erosive marly catchments of Draix (Southern Alps, France), downstream fining of <span class="hlt">sediments</span> has been observed and can not be explained by selective sorting. Moreover, high concentrations of suspended fine <span class="hlt">sediment</span> (up to 800 g/L) are measured during flood events in these basins. These observations lead to the hypothesis that abrasion and fragmentation of marly <span class="hlt">sediments</span> during <span class="hlt">transport</span> play an important role in the production of fine <span class="hlt">sediments</span>. Several experiments are conducted in order to quantify these processes: material from the river bed is introduced into the water flow in a circular flume as well as in a large scale rotating drum. Abrasion rates range from 5 to 15%/km, depending on the lithology: marls from the upper basin are more erosive than those from the lower basin. Modifications of grain size distribution in the rough fraction are also observed. Field measurements are also conducted. Downstream of the main marly <span class="hlt">sediment</span> sources, the river bed is composed of marls and limestone pebbles. We have sampled the river bed for analysis of grain size distribution and lithology. First results show a decrease of the proportion of marls along the river bed. This is in accordance with the high erosion rates observed in our laboratory experiments. Further investigations are planned in order to study more precisely marl grain size distribution, especially in the finer fraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890005649','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890005649"><span><span class="hlt">Sediment-transport</span> experiments in zero-gravity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Iversen, James D.; Greeley, Ronald</p> <p>1987-01-01</p> <p>One of the important parameters in the analysis of <span class="hlt">sediment</span> entrainment and <span class="hlt">transport</span> is gravitational attraction. The availability of a laboratory in earth orbit would afford an opportunity to conduct experiments in zero and variable gravity environments. Elimination of gravitational attraction as a factor in such experiments would enable other critical parameters (such as particle cohesion and aerodynamic forces) to be evaluated much more accurately. A Carousel Wind Tunnel (CWT) is proposed for use in conducting experiments concerning <span class="hlt">sediment</span> particle entrainment and <span class="hlt">transport</span> in a space station. In order to test the concept of this wind tunnel design a one third scale model CWT was constructed and calibrated. Experiments were conducted in the prototype to determine the feasibility of studying various aeolian processes and the results were compared with various numerical analysis. Several types of experiments appear to be feasible utilizing the proposed apparatus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860017681','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860017681"><span><span class="hlt">Sediment-transport</span> experiments in zero-gravity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Iversen, J. D.; Greeley, R.</p> <p>1986-01-01</p> <p>One of the important parameters in the analysis of <span class="hlt">sediment</span> entrainment and <span class="hlt">transport</span> is gravitational attraction. The availability of a laboratory in Earth orbit would afford an opportunity to conduct experiments in zero and variable gravity environments. Elimination of gravitational attraction as a factor in such experiments would enable other critical parameters (such as particle cohesion and aerodynamic forces) to be evaluated much more accurately. A Carousel Wind Tunnel (CWT) is proposed for use in conducting experiments concerning <span class="hlt">sediment</span> particle entrainment and <span class="hlt">transport</span> in a space station. In order to test the concept of this wind tunnel design a one third scale model CWT was constructed and calibrated. Experiments were conducted in the prototype to determine the feasibility of studying various aeolian processes and the results were compared with various numerical analysis. Several types of experiments appear to be feasible utilizing the proposed apparatus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036830','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036830"><span>Miocene mass-<span class="hlt">transport</span> <span class="hlt">sediments</span>, Troodos Massif, Cyprus</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lord, A.R.; Harrison, R.W.; BouDagher-Fadel, M.; Stone, B.D.; Varol, O.</p> <p>2009-01-01</p> <p><span class="hlt">Sediment</span> mass-<span class="hlt">transport</span> layers of submarine origin on the northern and southern flanks of the Troodos ophiolitic massif are dated biostratigraphically as early Miocene and late Miocene, respectively and therefore represent different seismogenic events in the uplift and erosional history of the Troodos terrane. Analysis of such events has potential for documenting Miocene seismic and uplift events regionally in the context of changing stress field directions and plate vectors through time. ?? 2009 The Geologists' Association.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1007544','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1007544"><span>Capabilities of the Large-Scale <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Facility</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2016-04-01</p> <p>experiments in wave /current environments. INTRODUCTION: The LSTF (Figure 1) is a large-scale laboratory facility capable of simulating conditions...comparable to low- wave energy coasts. The facility was constructed to address deficiencies in existing methods for calculating longshore <span class="hlt">sediment...transport</span>. The LSTF consists of a 30 m wide, 50 m long, 1.4 m deep basin. Waves are generated by four digitally controlled wave makers capable of producing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2012/1083/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2012/1083/"><span>Observations of coastal <span class="hlt">sediment</span> dynamics of the Tijuana Estuary Fine <span class="hlt">Sediment</span> Fate and <span class="hlt">Transport</span> Demonstration Project, Imperial Beach, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Warrick, Jonathan A.; Rosenberger, Kurt J.; Lam, Angela; Ferreiera, Joanne; Miller, Ian M.; Rippy, Meg; Svejkovsky, Jan; Mustain, Neomi</p> <p>2012-01-01</p> <p>Coastal restoration and management must address the presence, use, and <span class="hlt">transportation</span> of fine <span class="hlt">sediment</span>, yet little information exists on the patterns and/or processes of fine-<span class="hlt">sediment</span> <span class="hlt">transport</span> and deposition for these systems. To fill this information gap, a number of State of California, Federal, and private industry partners developed the Tijuana Estuary Fine <span class="hlt">Sediment</span> Fate and <span class="hlt">Transport</span> Demonstration Project ("Demonstration Project") with the purpose of monitoring the <span class="hlt">transport</span>, fate, and impacts of fine <span class="hlt">sediment</span> from beach-<span class="hlt">sediment</span> nourishments in 2008 and 2009 near the Tijuana River estuary, Imperial Beach, California. The primary purpose of the Demonstration Project was to collect and provide information about the directions, rates, and processes of fine-<span class="hlt">sediment</span> <span class="hlt">transport</span> along and across a California beach and nearshore setting. To achieve these goals, the U.S. Geological Survey monitored water, beach, and seafloor properties during the 2008–2009 Demonstration Project. The project utilized <span class="hlt">sediment</span> with ~40 percent fine <span class="hlt">sediment</span> by mass so that the dispersal and <span class="hlt">transport</span> of fine <span class="hlt">sediment</span> would be easily recognizable. The purpose of this report is to present and disseminate the data collected during the physical monitoring of the Demonstration Project. These data are available online at the links noted in the "Additional Digital Information" section. Synthesis of these data and results will be provided in subsequent publications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhDT.......289S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhDT.......289S"><span>Fluid flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> in evolving sedimentary basins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swenson, John Bradley</p> <p></p> <p>This thesis consists of three studies that focus on groundwater flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> in evolving sedimentary basins. The first study considers the subsurface hydrodynamic response to basin-scale transgression and regression and its implications for stratiform ore genesis. I demonstrate that the transgressive sequence focuses marginward-directed, compaction-driven discharge within a basal aquifer during progradation and deposition of the overlying regressive sequence, isolates the basal aquifer from overlying flow systems, and serves as a chemical sink for metal-bearing brines. In the second study, I develop a new theory for the shoreline response to subsidence, <span class="hlt">sediment</span> supply, and sea level. In this theory, <span class="hlt">sediment</span> <span class="hlt">transport</span> in a fluvio-deltaic basin is formally equivalent to heat transfer in a two-phase (liquid and isothermal solid) system: the fluvial system is analogous to a conduction-dominated liquid phase, the shoreline is the melting front, and the water depth at the delta toe is equivalent to the latent heat of fusion. A natural consequence of this theory is that <span class="hlt">sediment</span>-starved basins do not possess an equilibrium state. In contrast to existing theories, I do not observe either strong phase shifting or attenuation of the shoreline response to low-frequency eustatic forcing; rather, shoreline tracks sea level over a spectrum of forcing frequencies, and its response to low-frequency forcing is amplified relative to the high-frequency response. For the third study, I use a set of dimensionless numbers from the previous study as a mathematical framework for providing a unified treatment of existing stratigraphic theories. In the limit of low-amplitude eustatic forcing, my study suggests that strong phase shifting between shoreline and sea level is a consequence of specifying the <span class="hlt">sedimentation</span> rate at the shoreline; basins free of this constraint do not develop strong phase shifts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA571118','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA571118"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> on Continental Shelves: Storm Bed Formation and Preservation in Heterogeneous <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-01-01</p> <p>occurred during the Cretaceous period. The simulated storm bed for such an extratropical cyclone that lasts 4 days was deposited as deep as 75 m and had...Int. Assoc. Sedimentol. Spec. Publ. (2012) 44, 295-310 <span class="hlt">Sediment</span> <span class="hlt">transport</span> on continental shelves: storm bed formation and preservation in...xDept. of Earth Science, Memorial University of Newfoundland, St. Johns, Newfoundland, Canada ABSTRACT Many storm beds are constructed of silt/sand</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70038510','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70038510"><span>Erosion, storage, and <span class="hlt">transport</span> of <span class="hlt">sediment</span> in two subbasins of the Rio Puerco, New Mexico</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gellis, A.C.; Pavich, M.J.; Ellwein, A.L.; Aby, S.; Clark, I.; Wieczorek, M.E.; Viger, R.</p> <p>2012-01-01</p> <p>Arroyos in the American Southwest proceed through cut-and-fill cycles that operate at centennial to millennial time scales. The geomorphic community has put much effort into understanding the causes of arroyo cutting in the late Quaternary and in the modern record (late 1800s), while little effort has gone into understanding how arroyos fill and the sources of this fill. Here, we successfully develop a geographic information system (GIS)-modeled <span class="hlt">sediment</span> budget that is based on detailed field measurements of hillslope and channel erosion and deposition. Field measurements were made in two arroyo basins draining different lithologies and undergoing different land disturbance (Volcano Hill Wash, 9.30 km2; Arroyo Chavez, 2.11 km2) over a 3 yr period. Both basins have incised channels that formed in response to the late nineteenth-century incision of the Rio Puerco. Large volumes of <span class="hlt">sediment</span> were generated during arroyo incision, equal to more than 100 yr of the current annual total <span class="hlt">sediment</span> load (<span class="hlt">bed</span> <span class="hlt">load</span> + suspended load) in each basin. Downstream reaches in both arroyos are presently aggrading, and the main source of the <span class="hlt">sediment</span> is from channel erosion in upstream reaches and first- and second-order tributaries. The <span class="hlt">sediment</span> budget shows that channel erosion is the largest source of <span class="hlt">sediment</span> in the current stage of the arroyo cycle: 98% and 80% of the <span class="hlt">sediment</span> exported out of Volcano Hill Wash and Arroyo Chavez, respectively. The geomorphic surface most affected by arroyo incision and one of the most important <span class="hlt">sediment</span> sources is the valley alluvium, where channel erosion, gullying, soil piping, and grazing all occur. Erosion rates calculated for the entire Volcano Hill Wash (-0.26 mm/yr) and Arroyo Chavez (-0.53 mm/yr) basins are higher than the modeled upland erosion rates in each basin, reflecting the large contributions from channel erosion. Erosion rates in each basin are affected by a combination of land disturbance (grazing) and lithology</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMEP23C0832A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMEP23C0832A"><span>Impacts of biological diversity on <span class="hlt">sediment</span> <span class="hlt">transport</span> in streams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Albertson, L. K.; Cardinale, B. J.; Sklar, L. S.</p> <p>2012-12-01</p> <p>Over the past decade, an increasing number of studies have shown that biological structures (e.g. plant roots) have large impacts on <span class="hlt">sediment</span> <span class="hlt">transport</span>, and that physical models that do not incorporate these biological impacts can produce qualitatively incorrect predictions. But while it is now recognized that biological structures influence <span class="hlt">sediment</span> <span class="hlt">transport</span>, work to date has focused primarily on the impacts of individual, usually dominant, species. Here, we ask whether competitive interactions cause multi-species communities to have fundamentally different impacts on <span class="hlt">sediment</span> mobility than single-species systems. We use a model system with caddisfly larvae, which are insects that live in the benthic habitat of streams where they construct silken catchnets across pore spaces between rocks to filter food particles. Because caddisflies can reach densities of 1,000s per m2 with each larva spinning hundreds of silken threads between rocks, studies have shown that caddisflies reduce the probability of bed movement during high discharge events. To test whether streams with multiple species of caddisfly are stabilized any differently than single-species streams, we manipulated the presence or absence of two common species (Ceratopsyche oslari, Arctopsyche californica) in substrate patches (0.15 m2) in experimental stream channels (50-m long x 1-m wide) with fully controlled hydrology at the Sierra Nevada Aquatic Research Laboratory. This experiment was designed to extend the scale of previous laboratory mesocosm studies, which showed that critical shear stress is 31% higher in a multi-species flume mesocosm compared to a single-species mesocosm. Under these more realistic field conditions, we found that critical shear stress was, on average, 30% higher in streams with caddisflies vs. controls with no caddisflies. However, no differences were detected between treatments with 2 vs. 1 species. We hypothesize that the minimal effect of diversity on critical shear stress</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V23C2831R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V23C2831R"><span><span class="hlt">Transport</span> and <span class="hlt">sedimentation</span> in unconfined experimental dilute pyroclastic density currents</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramirez, G.; Andrews, B. J.; Dennen, R. L.</p> <p>2013-12-01</p> <p>We present results from experiments conducted in a new facility that permits the study of large, unconfined particle laden density currents that are dynamically similar to natural dilute pyroclastic density currents (PDCs). Experiments were run in a sealed, air-filled tank measuring 8.5 m long by 6.1 m wide by 2.6 m tall. Currents were generated by feeding mixture of heated particles (5 μm aluminum oxide, 25 μm talc, 27 μm walnut shell, 76 μm glass beads) down a chute at controlled rates to produce dilute, turbulent gravity currents. Comparison of experimental currents with natural PDCs shows good agreement between Froude, densimetric and thermal Richardson, and particle Stokes and settling numbers; experimental currents have lower Reynolds numbers than natural PDCs, but are fully turbulent. Currents were illuminated with 3 orthogonal laser sheets (650, 532, and 450 nm wavelengths) and recorded with an array of HD video cameras and a high speed camera (up to 3000 fps). Deposits were mapped using a grid of <span class="hlt">sedimentation</span> traps. We observe distinct differences between ambient temperature and warm currents: * warm currents have shorter run out distances, narrow map view distributions of currents and deposits, thicken with distance from the source, and lift off to form coignimbrite plumes; * ambient temperature currents typically travel farther, spread out radially, do not thicken greatly with <span class="hlt">transport</span> distance, and do not form coignimbrite plumes. Long duration currents (600 s compared to 30-100 s) oscillate laterally with time (e.g. <span class="hlt">transport</span> to the right, then the left, and back); this oscillation happens prior to any interaction with the tank walls. Isopach maps of the deposits show predictable trends in <span class="hlt">sedimentation</span> versus distance in response to eruption parameters (eruption rate, duration, temperature, and initial current mass), but all <span class="hlt">sedimentation</span> curves can be fit with 2nd order polynomials (R2>.9). Proximal <span class="hlt">sedimentation</span> is similar in comparable warm</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034454','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034454"><span>Nearshore Tsunami Inundation Model Validation: Toward <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Applications</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Apotsos, Alex; Buckley, Mark; Gelfenbaum, Guy; Jaffe, Bruce; Vatvani, Deepak</p> <p>2011-01-01</p> <p>Model predictions from a numerical model, Delft3D, based on the nonlinear shallow water equations are compared with analytical results and laboratory observations from seven tsunami-like benchmark experiments, and with field observations from the 26 December 2004 Indian Ocean tsunami. The model accurately predicts the magnitude and timing of the measured water levels and flow velocities, as well as the magnitude of the maximum inundation distance and run-up, for both breaking and non-breaking waves. The shock-capturing numerical scheme employed describes well the total decrease in wave height due to breaking, but does not reproduce the observed shoaling near the break point. The maximum water levels observed onshore near Kuala Meurisi, Sumatra, following the 26 December 2004 tsunami are well predicted given the uncertainty in the model setup. The good agreement between the model predictions and the analytical results and observations demonstrates that the numerical solution and wetting and drying methods employed are appropriate for modeling tsunami inundation for breaking and non-breaking long waves. Extension of the model to include <span class="hlt">sediment</span> <span class="hlt">transport</span> may be appropriate for long, non-breaking tsunami waves. Using available <span class="hlt">sediment</span> <span class="hlt">transport</span> formulations, the <span class="hlt">sediment</span> deposit thickness at Kuala Meurisi is predicted generally within a factor of 2.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=70716&Lab=NCER&keyword=water+AND+hydraulics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=70716&Lab=NCER&keyword=water+AND+hydraulics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>STAND, A DYNAMIC MODEL FOR <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> AND WATER QUALITY. (R825758)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><p>We introduce a new model–STAND (<span class="hlt">Sediment-Transport</span>-Associated Nutrient Dynamics)–for simulating stream flow, <span class="hlt">sediment</span> <span class="hlt">transport</span>, and the interactions of <span class="hlt">sediment</span> with other attributes of water quality. In contrast to other models, STAND employs a fully dynamic ba...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2767H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2767H"><span>Modeling <span class="hlt">sediment</span> <span class="hlt">transport</span> as a spatio-temporal Markov process.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heyman, Joris; Ancey, Christophe</p> <p>2014-05-01</p> <p>Despite a century of research about <span class="hlt">sediment</span> <span class="hlt">transport</span> by bedload occuring in rivers, its constitutive laws remain largely unknown. The proof being that our ability to predict mid-to-long term <span class="hlt">transported</span> volumes within reasonable confidence interval is almost null. The intrinsic fluctuating nature of bedload <span class="hlt">transport</span> may be one of the most important reasons why classical approaches fail. Microscopic probabilistic framework has the advantage of taking into account these fluctuations at the particle scale, to understand their effect on the macroscopic variables such as <span class="hlt">sediment</span> flux. In this framework, bedload <span class="hlt">transport</span> is seen as the random motion of particles (sand, gravel, pebbles...) over a two-dimensional surface (the river bed). The number of particles in motion, as well as their velocities, are random variables. In this talk, we show how a simple birth-death Markov model governing particle motion on a regular lattice accurately reproduces the spatio-temporal correlations observed at the macroscopic level. Entrainment, deposition and <span class="hlt">transport</span> of particles by the turbulent fluid (air or water) are supposed to be independent and memoryless processes that modify the number of particles in motion. By means of the Poisson representation, we obtained a Fokker-Planck equation that is exactly equivalent to the master equation and thus valid for all cell sizes. The analysis shows that the number of moving particles evolves locally far from thermodynamic equilibrium. Several analytical results are presented and compared to experimental data. The index of dispersion (or variance over mean ratio) is proved to grow from unity at small scales to larger values at larger scales confirming the non Poisonnian behavior of bedload <span class="hlt">transport</span>. Also, we study the one and two dimensional K-function, which gives the average number of moving particles located in a ball centered at a particle centroid function of the ball's radius.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP43F..08P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP43F..08P"><span>Modeling the Effects of Reservoir Releases on the Bed Material <span class="hlt">Sediment</span> Flux of the Colorado River in western Colorado and eastern Utah</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pitlick, J.; Bizzi, S.; Schmitt, R. J. P.</p> <p>2017-12-01</p> <p>Warm-water reaches of the upper Colorado River have historically provided important habitat for four endangered fishes. Over time these habitats have been altered or lost due to reductions in peak flows and <span class="hlt">sediment</span> loads caused by reservoir operations. In an effort to reverse these trends, controlled reservoir releases are now used to enhance <span class="hlt">sediment</span> <span class="hlt">transport</span> and restore channel complexity. In this presentation, we discuss the development of a <span class="hlt">sediment</span> routing model designed to assess how changes in water and <span class="hlt">sediment</span> supply can affect the mass balance of <span class="hlt">sediment</span>. The model is formulated for ten reaches of the Colorado River spanning 250 km where values of bankfull discharge, width, and reach-average slope have been measured. Bed surface grain size distributions (GSDs) have also been measured throughout the study area; these distributions are used as a test of the model, not as input, except as an upstream boundary condition. In modeling fluxes and GSDs, we assume that the <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> capacity is determined by local hydraulic conditions and bed surface grain sizes. Estimates of the bankfull <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> capacity in each reach are computed for 14 size fractions of the surface bed material, and the fractional <span class="hlt">transport</span> rates are summed to get the total <span class="hlt">transport</span> capacity. In the adjacent reach, fluxes of each size fraction from upstream are used to determine the mean grain size, and the fractional <span class="hlt">transport</span> capacity of that reach. Calculations proceed downstream and illustrate how linked changes in discharge, shear stress and mean grain size affect (1) the total <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> capacity, and (2) the size distribution of the bed surface <span class="hlt">sediment</span>. The results show that model-derived GSDs match measured GSDs very closely, except for two reaches in the lower part of the study area where slope is affected by uplift associated with salt diapirs; here the model significantly overestimates the <span class="hlt">transport</span> capacity in relation to the supply. Except for these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP42A..04G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP42A..04G"><span>Modeling <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Using a Lagrangian Particle Tracking Algorithm Coupled with High-Resolution Large Eddy Simulations: a Critical Analysis of Model Limits and Sensitivity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia, M. H.</p> <p>2016-12-01</p> <p>, (2011), Lagrangian model of <span class="hlt">bed-load</span> <span class="hlt">transport</span> in turbulent junction flows, Journal of Fluid Mechanics, 666,36-76. Niño and García, (1994), Gravel saltation: 2. Modeling, Water Resources Research, 30(6),1915-1924. Niño et al., (1994), Gravel saltation: 1. Experiments, Water Resources Research, 30(6), 1907-1914.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1715567A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1715567A"><span>Tailings dam-break flow - Analysis of <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aleixo, Rui; Altinakar, Mustafa</p> <p>2015-04-01</p> <p>A common solution to store mining debris is to build tailings dams near the mining site. These dams are usually built with local materials such as mining debris and are more vulnerable than concrete dams (Rico et al. 2008). of The tailings and the pond water generally contain heavy metals and various toxic chemicals used in ore extraction. Thus, the release of tailings due to a dam-break can have severe ecological consequences in the environment. A tailings dam-break has many similarities with a common dam-break flow. It is highly transient and can be severely descructive. However, a significant difference is that the released <span class="hlt">sediment</span>-water mixture will behave as a non-Newtonian flow. Existing numerical models used to simulate dam-break flows do not represent correctly the non-Newtonian behavior of tailings under a dam-break flow and may lead to unrealistic and incorrect results. The need for experiments to extract both qualitative and quantitative information regarding these flows is therefore real and actual. The present paper explores an existing experimental data base presented in Aleixo et al. (2014a,b) to further characterize the <span class="hlt">sediment</span> <span class="hlt">transport</span> under conditions of a severe transient flow and to extract quantitative information regarding <span class="hlt">sediment</span> flow rate, <span class="hlt">sediment</span> velocity, <span class="hlt">sediment-sediment</span> interactions a among others. Different features of the flow are also described and analyzed in detail. The analysis is made by means of imaging techniques such as Particle Image Velocimetry and Particle Tracking Velocimetry that allow extracting not only the velocity field but the Lagrangian description of the <span class="hlt">sediments</span> as well. An analysis of the results is presented and the limitations of the presented experimental approach are discussed. References Rico, M., Benito, G., Salgueiro, AR, Diez-Herrero, A. and Pereira, H.G. (2008) Reported tailings dam failures: A review of the European incidents in the worldwide context , Journal of Hazardous Materials, 152, 846</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/32966','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/32966"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> primer: estimating bed-material <span class="hlt">transport</span> in gravel-bed rivers</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Peter Wilcock; John Pitlick; Yantao Cui</p> <p>2009-01-01</p> <p>This primer accompanies the release of BAGS, software developed to calculate <span class="hlt">sediment</span> <span class="hlt">transport</span> rate in gravel-bed rivers. BAGS and other programs facilitate calculation and can reduce some errors, but cannot ensure that calculations are accurate or relevant. This primer was written to help the software user define relevant and tractable problems, select appropriate...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMEP23D0859S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMEP23D0859S"><span>Numerical simulation of turbulence and <span class="hlt">sediment</span> <span class="hlt">transport</span> of medium sand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmeeckle, M. W.</p> <p>2012-12-01</p> <p>Eleven numerical simulations, ranging from no <span class="hlt">transport</span> to bedload to vigorous suspension <span class="hlt">transport</span>, are presented of a combined large eddy simulation (LES) and distinct element model (DEM) of an initially flat bed of medium sand. The fluid and particles are fully coupled in momentum. The friction coefficient, defined here as the squared ratio of the friction velocity to the depth-averaged velocity, is in good agreement with well-known rough bed relations at no <span class="hlt">transport</span> and increases with the intensity of bedload <span class="hlt">transport</span>. The friction coefficient nearly doubles in value at the onset of <span class="hlt">sediment</span> suspension owing to a rapid increase of the depth over which particles and fluid exchange momentum. The friction coefficient decreases with increasing suspension intensity because of increasingly stable stratification. Fluid Reynolds stress and time-averaged velocity profiles in the bedload regime agree well with previous experiments and simulations. Also consistent with previous studies of suspended <span class="hlt">sediment</span>, there is an increase in slope of the lower portion of the velocity profile that has been modeled in the past using stably stratified eddy viscosity closures or an adjusted von Karman constant. Stokes numbers in the simulations, using an estimated lagrangian integral time scale, are less than unity. As such, particles faithfully follow the fluid, except for particle settling and grain-grain interactions near the bed. Fluid-particle velocity correlation coefficients approach one in portions of the flow where volumetric <span class="hlt">sediment</span> concentrations are below about ten percent. Bedload entrainment is critically connected to vertical velocity fluctuations. When a fluid packet approaches the bed from the interior of the flow (i.e. a sweep), fluid is forced into the bed, and at the edges of the sweep, fluid is forced out of the bed. Much of the particle entrainment occurs at these sweep edges. Fluid velocity statistics following the particles reveal that moving bedload</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRF..121..939S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRF..121..939S"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> through self-adjusting, bedrock-walled waterfall plunge pools</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scheingross, Joel S.; Lamb, Michael P.</p> <p>2016-05-01</p> <p>Many waterfalls have deep plunge pools that are often partially or fully filled with <span class="hlt">sediment</span>. <span class="hlt">Sediment</span> fill may control plunge-pool bedrock erosion rates, partially determine habitat availability for aquatic organisms, and affect <span class="hlt">sediment</span> routing and debris flow initiation. Currently, there exists no mechanistic model to describe <span class="hlt">sediment</span> <span class="hlt">transport</span> through waterfall plunge pools. Here we develop an analytical model to predict steady-state plunge-pool depth and <span class="hlt">sediment-transport</span> capacity by combining existing jet theory with <span class="hlt">sediment</span> <span class="hlt">transport</span> mechanics. Our model predicts plunge-pool <span class="hlt">sediment-transport</span> capacity increases with increasing river discharge, flow velocity, and waterfall drop height and decreases with increasing plunge-pool depth, radius, and grain size. We tested the model using flume experiments under varying waterfall and plunge-pool geometries, flow hydraulics, and <span class="hlt">sediment</span> size. The model and experiments show that through morphodynamic feedbacks, plunge pools aggrade to reach shallower equilibrium pool depths in response to increases in imposed <span class="hlt">sediment</span> supply. Our theory for steady-state pool depth matches the experiments with an R2 value of 0.8, with discrepancies likely due to model simplifications of the hydraulics and <span class="hlt">sediment</span> <span class="hlt">transport</span>. Analysis of 75 waterfalls suggests that the water depths in natural plunge pools are strongly influenced by upstream <span class="hlt">sediment</span> supply, and our model provides a mass-conserving framework to predict <span class="hlt">sediment</span> and water storage in waterfall plunge pools for <span class="hlt">sediment</span> routing, habitat assessment, and bedrock erosion modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=324561','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=324561"><span>Field and laboratory calibration of impact plates for measuring coarse <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>During 2008-2009, an array of impact plates instrumented with either accelerometers or geophones was installed over a channel spanning weir in the Elwha River in Washington, USA. The impact system is the first permanent installation of its kind in North America. The system was deployed to measure th...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009Geomo.105..106B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009Geomo.105..106B"><span>Aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> on a beach: Surface moisture, wind fetch, and mean <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bauer, B. O.; Davidson-Arnott, R. G. D.; Hesp, P. A.; Namikas, S. L.; Ollerhead, J.; Walker, I. J.</p> <p>2009-04-01</p> <p>Temporal and spatial changes in wind speed, wind direction, and moisture content are ubiquitous across sandy coastal beaches. Often these factors interact in unknown ways to create complexity that confounds our ability to model <span class="hlt">sediment</span> <span class="hlt">transport</span> at any point across the beach as well as our capacity to predict <span class="hlt">sediment</span> delivery into the adjacent foredunes. This study was designed to measure wind flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> over a beach and foredune at Greenwich Dunes, Prince Edward Island National Park, with the express purpose of addressing these complex interactions. Detailed measurements are reported for one stormy day, October 11, 2004, during which meteorological conditions were highly variable. Wind speed ranged from 4 ms - 1 to over 20 ms - 1 , wind direction was highly oblique varying between 60° and 85° from shore perpendicular, and moisture content of the sand surface ranged from a minimum of about 3% (by mass) to complete saturation depending on precipitation, tidal excursion, and storm surge that progressively inundated the beach. The data indicate that short-term variations (i.e., minutes to hours) in <span class="hlt">sediment</span> <span class="hlt">transport</span> across this beach arise predominantly because of short-term changes in wind speed, as is expected, but also because of variations in wind direction, precipitation intensity, and tide level. Even slight increases in wind speed are capable of driving more intense saltation events, but this relationship is mediated by other factors on this characteristically narrow beach. As the angle of wind approach becomes more oblique, the fetch distance increases and allows greater opportunity for the saltation system to evolve toward an equilibrium <span class="hlt">transport</span> state before reaching the foredunes. Whether the theoretically-predicted maximum rate of <span class="hlt">transport</span> is ever achieved depends on the character of the sand surface (e.g., grain size, slope, roughness, vegetation, moisture content) and on various attributes of the wind field (e.g., average wind</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/6704','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/6704"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> data and related information for selected coarse-bed streams and rivers in Idaho</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>John G. King; William W. Emmett; Peter J. Whiting; Robert P. Kenworthy; Jeffrey J. Barry</p> <p>2004-01-01</p> <p>This report and associated web site files provide <span class="hlt">sediment</span> <span class="hlt">transport</span> and related data for coarse-bed streams and rivers to potential users. Information on bedload and suspended <span class="hlt">sediment</span> <span class="hlt">transport</span>, streamflow, channel geometry, channel bed material, floodplain material, and large particle <span class="hlt">transport</span> is provided for 33 study reaches in Idaho that represent a wide range of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRF..122..875M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRF..122..875M"><span>A coupled vegetation/<span class="hlt">sediment</span> <span class="hlt">transport</span> model for dryland environments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mayaud, Jerome R.; Bailey, Richard M.; Wiggs, Giles F. S.</p> <p>2017-04-01</p> <p>Dryland regions are characterized by patchy vegetation, erodible surfaces, and erosive aeolian processes. Understanding how these constituent factors interact and shape landscape evolution is critical for managing potential environmental and anthropogenic impacts in drylands. However, modeling wind erosion on partially vegetated surfaces is a complex problem that has remained challenging for researchers. We present the new, coupled cellular automaton Vegetation and <span class="hlt">Sediment</span> <span class="hlt">TrAnsport</span> (ViSTA) model, which is designed to address fundamental questions about the development of arid and semiarid landscapes in a spatially explicit way. The technical aspects of the ViSTA model are described, including a new method for directly imposing oblique wind and <span class="hlt">transport</span> directions onto a cell-based domain. Verification tests for the model are reported, including stable state solutions, the impact of drought and fire stress, wake flow dynamics, temporal scaling issues, and the impact of feedbacks between <span class="hlt">sediment</span> movement and vegetation growth on landscape morphology. The model is then used to simulate an equilibrium nebkha dune field, and the resultant bed forms are shown to have very similar size and spacing characteristics to nebkhas observed in the Skeleton Coast, Namibia. The ViSTA model is a versatile geomorphological tool that could be used to predict threshold-related transitions in a range of dryland ecogeomorphic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033128','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033128"><span>Calibration of an estuarine <span class="hlt">sediment</span> <span class="hlt">transport</span> model to <span class="hlt">sediment</span> fluxes as an intermediate step for simulation of geomorphic evolution</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ganju, N.K.; Schoellhamer, D.H.</p> <p>2009-01-01</p> <p>Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed <span class="hlt">sediment</span> and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and <span class="hlt">sediment</span> <span class="hlt">transport</span> models used for this purpose typically are calibrated to water level, currents, and/or suspended-<span class="hlt">sediment</span> concentrations. However, small errors in these tidal-timescale models can accumulate to cause major errors in geomorphic evolution, which may not be obvious. Here we present an intermediate step towards simulating decadal-timescale geomorphic change: calibration to estimated <span class="hlt">sediment</span> fluxes (mass/time) at two cross-sections within an estuary. Accurate representation of <span class="hlt">sediment</span> fluxes gives confidence in representation of <span class="hlt">sediment</span> supply to and from the estuary during those periods. Several years of <span class="hlt">sediment</span> flux data are available for the landward and seaward boundaries of Suisun Bay, California, the landward-most embayment of San Francisco Bay. <span class="hlt">Sediment</span> flux observations suggest that episodic freshwater flows export <span class="hlt">sediment</span> from Suisun Bay, while gravitational circulation during the dry season imports <span class="hlt">sediment</span> from seaward sources. The Regional Oceanic Modeling System (ROMS), a three-dimensional coupled hydrodynamic/<span class="hlt">sediment</span> <span class="hlt">transport</span> model, was adapted for Suisun Bay, for the purposes of hindcasting 19th and 20th century bathymetric change, and simulating geomorphic response to sea level rise and climatic variability in the 21st century. The <span class="hlt">sediment</span> <span class="hlt">transport</span> parameters were calibrated using the <span class="hlt">sediment</span> flux data from 1997 (a relatively wet year) and 2004 (a relatively dry year). The remaining years of data (1998, 2002, 2003) were used for validation. The model represents the inter-annual and annual <span class="hlt">sediment</span> flux variability, while net <span class="hlt">sediment</span> import/export is accurately modeled for three of the five years. The use of <span class="hlt">sediment</span> flux data for calibrating an estuarine geomorphic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27548505','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27548505"><span>Bead-Based Microfluidic <span class="hlt">Sediment</span> Analogues: Fabrication and Colloid <span class="hlt">Transport</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Yang; Huang, Jingwei; Xiao, Feng; Yin, Xiaolong; Chun, Jaehun; Um, Wooyong; Neeves, Keith B; Wu, Ning</p> <p>2016-09-13</p> <p>Mobile colloids can act as carriers for low-solubility contaminants in the environment. However, the dominant mechanism for this colloid-facilitated <span class="hlt">transport</span> of chemicals is unclear. Therefore, we developed a bead-based microfluidic platform of <span class="hlt">sediment</span> analogues and measured both single and population <span class="hlt">transport</span> of model colloids. The porous medium is assembled through a bead-by-bead injection method. This approach has the versatility to build both electrostatically homogeneous and heterogeneous media at the pore scale. A T-junction at the exit also allowed for encapsulation and enumeration of colloids effluent at single particle resolution to give population dynamics. Tortuosity calculated from pore-scale trajectory analysis and its comparison with lattice Boltzmann simulations revealed that <span class="hlt">transport</span> of colloids was influenced by the size exclusion effect. The porous media packed by positively and negatively charged beads into two layers showed distinctive colloidal particle retention and significant remobilization and re-adsorption of particles during water flushing. We demonstrated the potential of our method to fabricate porous media with surface heterogeneities at the pore scale. With both single and population dynamics measurement, our platform has the potential to connect pore-scale and macroscale colloid <span class="hlt">transport</span> on a lab scale and to quantify the impact of grain surface heterogeneities that are natural in the subsurface environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5169M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5169M"><span>A model study of <span class="hlt">sediment</span> <span class="hlt">transport</span> across the shelf break</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marchal, Olivier</p> <p>2017-04-01</p> <p>A variety of dynamical processes can contribute to the <span class="hlt">transport</span> of material (e.g., particulate matter) across the shelf break - the region separating the continental shelf from the continental slope. Among these processes are (i) the reflection of internal waves on the outer shelf and upper slope, and (ii) the instability of hydrographic fronts, roughly aligned with isobaths, that are often present at the shelf break. On the one hand, internal waves reflecting on a sloping boundary can produce bottom shear stresses that are large enough to resuspend non-cohesive <span class="hlt">sediments</span> into the water column. On the other hand, eddies shed from unstable shelf break fronts can incorporate into their core particle-rich waters from the outer shelf and upper slope, and <span class="hlt">transport</span> these waters offshore. Here we present numerical experiments with a three-dimensional numerical model of ocean circulation and <span class="hlt">sediment</span> <span class="hlt">transport</span>, which illustrate the joint effect of internal waves and eddies on <span class="hlt">sediment</span> <span class="hlt">transport</span> across the shelf break. The model is based on the primitive equations and terrain-following coordinates. The model domain is square and idealized, comprising a flat continental shelf, a constant continental slope, and a flat abyssal basin. The model grid has O(1 km) horizontal resolution, so that (sub)mesoscale eddies observed in the vicinity of shelf breaks, such as south of New England, can be represented in detail. Internal waves are excited through the specification of a periodic variation in the across-slope component of velocity at the offshore boundary of the domain, and eddies are generated from the baroclinic instability of a shelf break jet that is initially in strict thermal wind balance. Numerical experiments are conducted that are characterized by (i) different slopes of internal wave characteristics relative to the continental slope, representing sub-critical, critical, and super-critical regimes, and (ii) different values for the dimensionless ratios that emerge</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21499572','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21499572"><span>Tidal and meteorological forcing of <span class="hlt">sediment</span> <span class="hlt">transport</span> in tributary mudflat channels.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ralston, David K; Stacey, Mark T</p> <p>2007-06-01</p> <p>Field observations of flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> in a tributary channel through intertidal mudflats indicate that suspended <span class="hlt">sediment</span> was closely linked to advection and dispersion of a tidal salinity front. During calm weather when tidal forcing was dominant, high concentrations of suspended <span class="hlt">sediment</span> advected up the mudflat channel in the narrow region between salty water from San Francisco Bay and much fresher runoff from the small local watershed. Salinity and suspended <span class="hlt">sediment</span> dispersed at similar rates through each tidal inundation, such that during receding ebbs the <span class="hlt">sediment</span> pulse had spread spatially and maximum concentrations had decreased. Net <span class="hlt">sediment</span> <span class="hlt">transport</span> was moderately onshore during the calm weather, as asymmetries in stratification due to tidal straining of the salinity front enhanced deposition, particularly during weaker neap tidal forcing. <span class="hlt">Sediment</span> <span class="hlt">transport</span> by tidal forcing was periodically altered by winter storms. During storms, strong winds from the south generated wind waves and temporarily increased suspended <span class="hlt">sediment</span> concentrations. Increased discharge down the tributary channels due to precipitation had more lasting impact on <span class="hlt">sediment</span> <span class="hlt">transport</span>, supplying both buoyancy and fine <span class="hlt">sediment</span> to the system. Net <span class="hlt">sediment</span> <span class="hlt">transport</span> depended on the balance between calm weather tidal forcing and perturbations by episodic storms. Net <span class="hlt">transport</span> in the tributary channel was generally off-shore during storms and during calm weather spring tides, and on-shore during calm weather neap tides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3076693','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3076693"><span>Tidal and meteorological forcing of <span class="hlt">sediment</span> <span class="hlt">transport</span> in tributary mudflat channels</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ralston, David K.; Stacey, Mark T.</p> <p>2011-01-01</p> <p>Field observations of flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> in a tributary channel through intertidal mudflats indicate that suspended <span class="hlt">sediment</span> was closely linked to advection and dispersion of a tidal salinity front. During calm weather when tidal forcing was dominant, high concentrations of suspended <span class="hlt">sediment</span> advected up the mudflat channel in the narrow region between salty water from San Francisco Bay and much fresher runoff from the small local watershed. Salinity and suspended <span class="hlt">sediment</span> dispersed at similar rates through each tidal inundation, such that during receding ebbs the <span class="hlt">sediment</span> pulse had spread spatially and maximum concentrations had decreased. Net <span class="hlt">sediment</span> <span class="hlt">transport</span> was moderately onshore during the calm weather, as asymmetries in stratification due to tidal straining of the salinity front enhanced deposition, particularly during weaker neap tidal forcing. <span class="hlt">Sediment</span> <span class="hlt">transport</span> by tidal forcing was periodically altered by winter storms. During storms, strong winds from the south generated wind waves and temporarily increased suspended <span class="hlt">sediment</span> concentrations. Increased discharge down the tributary channels due to precipitation had more lasting impact on <span class="hlt">sediment</span> <span class="hlt">transport</span>, supplying both buoyancy and fine <span class="hlt">sediment</span> to the system. Net <span class="hlt">sediment</span> <span class="hlt">transport</span> depended on the balance between calm weather tidal forcing and perturbations by episodic storms. Net <span class="hlt">transport</span> in the tributary channel was generally off-shore during storms and during calm weather spring tides, and on-shore during calm weather neap tides. PMID:21499572</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AdWR..111..395C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AdWR..111..395C"><span>Generation of net <span class="hlt">sediment</span> <span class="hlt">transport</span> by velocity skewness in oscillatory sheet flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Xin; Li, Yong; Chen, Genfa; Wang, Fujun; Tang, Xuelin</p> <p>2018-01-01</p> <p>This study utilizes a qualitative approach and a two-phase numerical model to investigate net <span class="hlt">sediment</span> <span class="hlt">transport</span> caused by velocity skewness beneath oscillatory sheet flow and current. The qualitative approach is derived based on the pseudo-laminar approximation of boundary layer velocity and exponential approximation of concentration. The two-phase model can obtain well the instantaneous erosion depth, <span class="hlt">sediment</span> flux, boundary layer thickness, and <span class="hlt">sediment</span> <span class="hlt">transport</span> rate. It can especially illustrate the difference between positive and negative flow stages caused by velocity skewness, which is considerably important in determining the net boundary layer flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> direction. The two-phase model also explains the effect of <span class="hlt">sediment</span> diameter and phase-lag to <span class="hlt">sediment</span> <span class="hlt">transport</span> by comparing the instantaneous-type formulas to better illustrate velocity skewness effect. In previous studies about sheet flow <span class="hlt">transport</span> in pure velocity-skewed flows, net <span class="hlt">sediment</span> <span class="hlt">transport</span> is only attributed to the phase-lag effect. In the present study with the qualitative approach and two-phase model, phase-lag effect is shown important but not sufficient for the net <span class="hlt">sediment</span> <span class="hlt">transport</span> beneath pure velocity-skewed flow and current, while the asymmetric wave boundary layer development between positive and negative flow stages also contributes to the <span class="hlt">sediment</span> <span class="hlt">transport</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70011431','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70011431"><span>Ice rafting of fine-grained <span class="hlt">sediment</span>, a sorting and <span class="hlt">transport</span> mechanism, Beaufort Sea, Alaska.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Barnes, P.W.; Reimnitz, E.; Fox, D.</p> <p>1982-01-01</p> <p>The presence of turbid, <span class="hlt">sediment</span>-rich fast ice in the Arctic is a major factor affecting <span class="hlt">transport</span> of fine-grained <span class="hlt">sediment</span>. Observers have documented the widespread, sporadic occurrence of <span class="hlt">sediment</span>- rich fast ice in both the Beaufort and Bering Seas. The occurrence of <span class="hlt">sediment</span> in only the upper part of the seasonal fast ice indicates that <span class="hlt">sediment</span>-rich ice forms early during ice growth. The most likely mechanism requires resuspension of nearshore bottom <span class="hlt">sediment</span> during storms, accompanied by formation of frazil ice and subsequent lateral advection before the fast ice is stabilized. We estimate that the <span class="hlt">sediment</span> incorporated in the Beaufort ice canopy formed a significant proportion of the seasonal influx of terrigenous fine-grained <span class="hlt">sediment</span>. The dominance of fine-grained <span class="hlt">sediment</span> suggests that in the Arctic and sub-Arctic these size fractions may be ice rafted in greater volumes than the coarse fraction of traditionally recognized ice-rafted <span class="hlt">sediment</span>. -from Authors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2432I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2432I"><span>Compositon of <span class="hlt">sediments</span> <span class="hlt">transported</span> by the wind at different heights</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iturri, Antonela; Funk, Roger; Leue, Martin; Sommer, Michael; Buschiazzo, Daniel</p> <p>2017-04-01</p> <p>Wind erosion (WE) is one of the most important degradation process of soils in arid- and semiarid environments in the world, affecting soil properties and adjacent ecosystems, including human health. Estimations about the amount of eroded soil are available in Argentina and in the world, but the quality of the eroded <span class="hlt">sediments</span>, particularly the sorting effects in agricultural soils, has been scarcely studied. The trend of the different mineral and organic soil compounds, which enrich in different size classes, can define height distribution profiles. Therefore, the uppermost 2.5 cm of four agricultural loess soils that differ in granulometric composition were used for WE simulations in a wind tunnel. Particles with a diameter smaller than 10 µm (PM10) were collected with a laboratory dust generator. The bulk soil and all the <span class="hlt">sediment</span> samples were characterized by the granulometric composition, the soil organic carbon (SOC) content and the mineral and organic functional groups. Despite different texture, the soils were subjected to similar sorting processes in height, but differed depending on their granulometry. There was a separation between coarser and finer soil particles in coarser textured soils, while finer textured soils were more homogeneous in all heights. This correlated with the preferential <span class="hlt">transport</span> of Si-O from quartz and C-H, C=O and C-C from soil organic matter (SOM), which were <span class="hlt">transported</span> in larger and/or denser particles at lower heights. O-H from clay minerals and C-O-C and C-O from polysaccharides, carbohydrates and derivatives from SOM were <span class="hlt">transported</span> in higher heights. Despite similar SOC content in the bulk soils, both the amount and composition in the PM10 fractions was different. The SOC <span class="hlt">transported</span> at higher heights was mostly composed of polysaccharides, carbohydrates and derivatives associated with clay minerals. The SOC in PM10 fractions of coarser-textured soils was dominated by labile C-H groups. According to the determined height</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=64140&Lab=NERL&keyword=Time+AND+Series+AND+Design&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=64140&Lab=NERL&keyword=Time+AND+Series+AND+Design&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>ONE-DIMENSIONAL HYDRODYNAMIC/<span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> MODEL FOR STREAM NETWORKS: TECHNICAL REPORT</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This technical report describes a new <span class="hlt">sediment</span> <span class="hlt">transport</span> model and the supporting post-processor, and sampling procedures for <span class="hlt">sediments</span> in streams. Specifically, the following items are described herein:<br><br> EFDC1D - This is a new one-dimensional hydrodynamic and <span class="hlt">sediment</span> tr...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=313314','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=313314"><span>Effect of <span class="hlt">sediment</span> <span class="hlt">transport</span> boundary conditions on the numerical modeling of bed morphodynamics</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Experimental <span class="hlt">sediment</span> <span class="hlt">transport</span> studies in laboratory flumes can use two <span class="hlt">sediment</span>-supply methods: an imposed feed at the upstream end or recirculation of <span class="hlt">sediment</span> from the downstream end to the upstream end. These methods generally produce similar equilibrium bed morphology, but temporal evolution c...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27064863','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27064863"><span>Electrically induced displacement <span class="hlt">transport</span> of immiscible oil in saline <span class="hlt">sediments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pamukcu, Sibel; Shrestha, Reena A; Ribeiro, Alexandra B; Mateus, Eduardo P</p> <p>2016-08-05</p> <p>Electrically assisted mitigation of coastal <span class="hlt">sediment</span> oil pollution was simulated in floor-scale laboratory experiments using light crude oil and saline water at approximately 1/10 oil/water (O/W) mass ratio in pore fluid. The mass <span class="hlt">transport</span> of the immiscible liquid phases was induced under constant direct current density of 2A/m(2), without water flooding. The transient pore water pressures (PWP) and the voltage differences (V) at and in between consecutive ports lined along the test specimen cell were measured over 90days. The oil phase <span class="hlt">transport</span> occurred towards the anode half of the test specimen where the O/W volume ratio increased by 50% over its initial value within that half-length of the specimen. In contrast, the O/W ratio decreased within the cathode side half of the specimen. During this time, the PWP decreased systematically at the anode side with oil bank accumulation. PWP increased at the cathode side of the specimen, signaling increased concentration of water there as it replaced oil in the pore space. Electrically induced <span class="hlt">transport</span> of the non-polar, non-conductive oil was accomplished in the opposing direction of flow by displacement in absence of viscous coupling of oil-water phases. Copyright © 2016 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP24B..07A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP24B..07A"><span>Numerical Model of Turbulence, <span class="hlt">Sediment</span> <span class="hlt">Transport</span>, and <span class="hlt">Sediment</span> Cover in a Large Canyon-Bound River</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alvarez, L. V.; Schmeeckle, M. W.</p> <p>2013-12-01</p> <p>The Colorado River in Grand Canyon is confined by bedrock and coarse-grained <span class="hlt">sediments</span>. Finer grain sizes are supply limited, and sandbars primarily occur in lateral separation eddies downstream of coarse-grained tributary debris fans. These sandbars are important resources for native fish, recreational boaters, and as a source of aeolian <span class="hlt">transport</span> preventing the erosion of archaeological resources by gully extension. Relatively accurate prediction of deposition and, especially, erosion of these sandbar beaches has proven difficult using two- and three-dimensional, time-averaged morphodynamic models. We present a parallelized, three-dimensional, turbulence-resolving model using the Detached-Eddy Simulation (DES) technique. DES is a hybrid large eddy simulation (LES) and Reynolds-averaged Navier Stokes (RANS). RANS is applied to the near-bed grid cells, where grid resolution is not sufficient to fully resolve wall turbulence. LES is applied further from the bed and banks. We utilize the Spalart-Allmaras one equation turbulence closure with a rough wall extension. The model resolves large-scale turbulence using DES and simultaneously integrates the suspended <span class="hlt">sediment</span> advection-diffusion equation. The Smith and McLean suspended <span class="hlt">sediment</span> boundary condition is used to calculate the upward and downward settling of <span class="hlt">sediment</span> fluxes in the grid cells attached to the bed. The model calculates the entrainment of five grain sizes at every time step using a mixing layer model. Where the mixing layer depth becomes zero, the net entrainment is zero or negative. As such, the model is able to predict the exposure and burial of bedrock and coarse-grained surfaces by fine-grained <span class="hlt">sediments</span>. A separate program was written to automatically construct the computational domain between the water surface and a triangulated surface of a digital elevation model of the given river reach. Model results compare favorably with ADCP measurements of flow taken on the Colorado River in Grand Canyon</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://acwi.gov/sos/pubs/2ndJFIC/Contents/5C_Boudreau_02_25_10_paper.pdf','USGSPUBS'); return false;" href="http://acwi.gov/sos/pubs/2ndJFIC/Contents/5C_Boudreau_02_25_10_paper.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> on Cape Sable, Everglades National Park, Florida</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zucker, Mark; Boudreau, Carrie</p> <p>2010-01-01</p> <p>The Cape Sable peninsula is located on the southwestern tip of the Florida peninsula within Everglades National Park (ENP). Lake Ingraham, the largest lake within Cape Sable, is now connected to the Gulf of Mexico and western Florida Bay by canals built in the early 1920's. Some of these canals breached a natural marl ridge located to the north of Lake Ingraham. These connections altered the landscape of this area allowing for the <span class="hlt">transport</span> of <span class="hlt">sediments</span> to and from Lake Ingraham. Saline intrusion into the formerly fresh interior marsh has impacted the local ecology. Earthen dams installed in the 1950's and 1960's in canals that breached the marl ridge have repeatedly failed. Sheet pile dams installed in the early 1990's subsequently failed resulting in the continued alteration of Lake Ingraham and the interior marsh. The Cape Sable Canals Dam Restoration Project, funded by ENP, proposes to restore the two failed dams in Lake Ingraham. The objective of this study was to collect discharge and water quality data over a series of tidal cycles and flow conditions to establish discharge and <span class="hlt">sediment</span> surrogate relations prior to initiating the Cape Sable Canals Dam Restoration Project. A dry season synoptic sampling event was performed on April 27-30, 2009.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..94f2609H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..94f2609H"><span>Rheology of <span class="hlt">sediment</span> <span class="hlt">transported</span> by a laminar flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Houssais, M.; Ortiz, C. P.; Durian, D. J.; Jerolmack, D. J.</p> <p>2016-12-01</p> <p>Understanding the dynamics of fluid-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> remains challenging, as it occurs at the interface between a granular material and a fluid flow. Boyer, Guazzelli, and Pouliquen [Phys. Rev. Lett. 107, 188301 (2011)], 10.1103/PhysRevLett.107.188301 proposed a local rheology unifying dense dry-granular and viscous-suspension flows, but it has been validated only for neutrally buoyant particles in a confined and homogeneous system. Here we generalize the Boyer, Guazzelli, and Pouliquen model to account for the weight of a particle by addition of a pressure P0 and test the ability of this model to describe <span class="hlt">sediment</span> <span class="hlt">transport</span> in an idealized laboratory river. We subject a bed of settling plastic particles to a laminar-shear flow from above, and use refractive-index-matching to track particles' motion and determine local rheology—from the fluid-granular interface to deep in the granular bed. Data from all experiments collapse onto a single curve of friction μ as a function of the viscous number Iv over the range 3 ×10-5 ≤Iv≤2 , validating the local rheology model. For Iv<3 ×10-5 , however, data do not collapse. Instead of undergoing a jamming transition with μ →μs as expected, particles transition to a creeping regime where we observe a continuous decay of the friction coefficient μ ≤μs as Iv decreases. The rheology of this creep regime cannot be described by the local model, and more work is needed to determine whether a nonlocal rheology model can be modified to account for our findings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999WRR....35..243M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999WRR....35..243M"><span>Streamflow record extension using power transformations and application to <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moog, Douglas B.; Whiting, Peter J.; Thomas, Robert B.</p> <p>1999-01-01</p> <p>To obtain a representative set of flow rates for a stream, it is often desirable to fill in missing data or extend measurements to a longer time period by correlation to a nearby gage with a longer record. Linear least squares regression of the logarithms of the flows is a traditional and still common technique. However, its purpose is to generate optimal estimates of each day's discharge, rather than the population of discharges, for which it tends to underestimate variance. Maintenance-of-variance-extension (MOVE) equations [Hirsch, 1982] were developed to correct this bias. This study replaces the logarithmic transformation by the more general Box-Cox scaled power transformation, generating a more linear, constant-variance relationship for the MOVE extension. Combining the Box-Cox transformation with the MOVE extension is shown to improve accuracy in estimating order statistics of flow rate, particularly for the nonextreme discharges which generally govern cumulative <span class="hlt">transport</span> over time. This advantage is illustrated by prediction of cumulative fractions of total <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=159044&Lab=NERL&keyword=innovation+AND+management&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=159044&Lab=NERL&keyword=innovation+AND+management&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>EVALUATION OF THE STATE-OF-THE-ART CONTAMINATED <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> AND FATE MODELING SYSTEM</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Modeling approaches for evaluating the <span class="hlt">transport</span> and fate of <span class="hlt">sediment</span> and associated contaminants are briefly reviewed. The main emphasis is on: 1) the application of EFDC (Environmental Fluid Dynamics Code), the state-of-the-art contaminated <span class="hlt">sediment</span> <span class="hlt">transport</span> and fate public do...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2009/5104/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2009/5104/"><span>A Tidally Averaged <span class="hlt">Sediment-Transport</span> Model for San Francisco Bay, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lionberger, Megan A.; Schoellhamer, David H.</p> <p>2009-01-01</p> <p>A tidally averaged <span class="hlt">sediment-transport</span> model of San Francisco Bay was incorporated into a tidally averaged salinity box model previously developed and calibrated using salinity, a conservative tracer (Uncles and Peterson, 1995; Knowles, 1996). The Bay is represented in the model by 50 segments composed of two layers: one representing the channel (>5-meter depth) and the other the shallows (0- to 5-meter depth). Calculations are made using a daily time step and simulations can be made on the decadal time scale. The <span class="hlt">sediment-transport</span> model includes an erosion-deposition algorithm, a bed-<span class="hlt">sediment</span> algorithm, and <span class="hlt">sediment</span> boundary conditions. Erosion and deposition of bed <span class="hlt">sediments</span> are calculated explicitly, and suspended <span class="hlt">sediment</span> is <span class="hlt">transported</span> by implicitly solving the advection-dispersion equation. The bed-<span class="hlt">sediment</span> model simulates the increase in bed strength with depth, owing to consolidation of fine <span class="hlt">sediments</span> that make up San Francisco Bay mud. The model is calibrated to either net <span class="hlt">sedimentation</span> calculated from bathymetric-change data or measured suspended-<span class="hlt">sediment</span> concentration. Specified boundary conditions are the tributary fluxes of suspended <span class="hlt">sediment</span> and suspended-<span class="hlt">sediment</span> concentration in the Pacific Ocean. Results of model calibration and validation show that the model simulates the trends in suspended-<span class="hlt">sediment</span> concentration associated with tidal fluctuations, residual velocity, and wind stress well, although the spring neap tidal suspended-<span class="hlt">sediment</span> concentration variability was consistently underestimated. Model validation also showed poor simulation of seasonal <span class="hlt">sediment</span> pulses from the Sacramento-San Joaquin River Delta at Point San Pablo because the pulses enter the Bay over only a few days and the fate of the pulses is determined by intra-tidal deposition and resuspension that are not included in this tidally averaged model. The model was calibrated to net-basin <span class="hlt">sedimentation</span> to calculate budgets of <span class="hlt">sediment</span> and <span class="hlt">sediment</span>-associated contaminants. While</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1001656','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1001656"><span>Littoral Hydrodynamics and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Around a Semi-Permeable Breakwater</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-09-18</p> <p>Australasian Coasts & Ports Conference 2015 15 - 18 September 2015, Auckland , New Zealand Li, H et al. Littoral Hydrodynamics and <span class="hlt">Sediment</span>...Coasts and Ports 2015, Auckland , New Zealand, 15-18 September, 2015, 7 pp. Littoral Hydrodynamics and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Around a Semi...Conference 2015 15 - 18 September 2015, Auckland , New Zealand Li, H et al. Littoral Hydrodynamics and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> 2 The bathymetric and side</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP11E..05M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP11E..05M"><span>Direct sampling during multiple <span class="hlt">sediment</span> density flows reveals dynamic <span class="hlt">sediment</span> <span class="hlt">transport</span> and depositional environment in Monterey submarine canyon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maier, K. L.; Gales, J. A.; Paull, C. K.; Gwiazda, R.; Rosenberger, K. J.; McGann, M.; Lundsten, E. M.; Anderson, K.; Talling, P.; Xu, J.; Parsons, D. R.; Barry, J.; Simmons, S.; Clare, M. A.; Carvajal, C.; Wolfson-Schwehr, M.; Sumner, E.; Cartigny, M.</p> <p>2017-12-01</p> <p> in the experiment. The comprehensive scale of the Monterey Coordinated Canyon Experiment allows us to integrate <span class="hlt">sediment</span> traps with ADCP instrument data and seafloor core samples, which provides important new data to constrain how, when, and what <span class="hlt">sediment</span> is <span class="hlt">transported</span> through submarine canyons and how this is archived in seafloor deposits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH13E..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH13E..01S"><span>Role of <span class="hlt">sediment</span> <span class="hlt">transport</span> model to improve the tsunami numerical simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sugawara, D.; Yamashita, K.; Takahashi, T.; Imamura, F.</p> <p>2015-12-01</p> <p>Are we overlooking an important factor for improved numerical prediction of tsunamis in shallow sea to onshore? In this presentation, several case studies on numerical modeling of tsunami-induced <span class="hlt">sediment</span> <span class="hlt">transport</span> are reviewed, and the role of <span class="hlt">sediment</span> <span class="hlt">transport</span> models for tsunami inundation simulation is discussed. Large-scale <span class="hlt">sediment</span> <span class="hlt">transport</span> and resulting geomorphological change occurred in the coastal areas of Tohoku, Japan, due to the 2011 Tohoku Earthquake Tsunami. Datasets obtained after the tsunami, including geomorphological and sedimentological data as well as hydrodynamic records, allows us to validate the numerical model in detail. The numerical modeling of the <span class="hlt">sediment</span> <span class="hlt">transport</span> by the 2011 tsunami depicted the severest erosion of sandy beach, as well as characteristic spatial patterns of erosion and deposition on the seafloor, which have taken place in Hirota Bay, Sanriku Coast. Quantitative comparisons of observation and simulation of the geomorphological changes in Sanriku Coast and Sendai Bay showed that the numerical model can predict the volumes of erosion and deposition with a right order. In addition, comparison of the simulation with aerial video footages demonstrated the numerical model is capable of tracking the overall processes of tsunami <span class="hlt">sediment</span> <span class="hlt">transport</span>. Although tsunami-induced <span class="hlt">sediment</span> erosion and deposition sometimes cause significant geomorphological change, and may enhance tsunami hydrodynamic impact to the coastal zones, most tsunami simulations do not include <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling. A coupled modeling of tsunami hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> draws a different picture of tsunami hazard, comparing with simple hydrodynamic modeling of tsunami inundation. Since tsunami-induced erosion, deposition and geomorphological change sometimes extend more than several kilometers across the coastline, two-dimensional horizontal model are typically used for the computation of tsunami hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP33B1937B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP33B1937B"><span>Reconstructing <span class="hlt">Sediment</span> Supply, <span class="hlt">Transport</span> and Deposition Behind the Elwha River Dams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beveridge, C.</p> <p>2017-12-01</p> <p>The Elwha River watershed in Olympic National Park of Washington State, USA is predominantly a steep, mountainous landscape where dominant geomorphic processes include landslides, debris flows and gullying. The river is characterized by substantial variability of channel morphology and fluvial processes, and alternates between narrow bedrock canyons and wider alluvial reaches for much of its length. Literature suggests that the Elwha watershed is topographically and tectonically in steady state. The removal of the two massive hydropower dams along the river in 2013 marked the largest dam removal in history. Over the century long lifespan of the dams, approximately 21 million cubic meters of <span class="hlt">sediment</span> was impounded behind them. Long term erosion rates documented in this region and reservoir <span class="hlt">sedimentation</span> data give unprecedented opportunities to test watershed <span class="hlt">sediment</span> yield models and examine dominant processes that control <span class="hlt">sediment</span> yield over human time scales. In this study, we aim to reconstruct <span class="hlt">sediment</span> supply, <span class="hlt">transport</span> and deposition behind the Glines Canyon Dam (most upstream dam) over its lifespan using a watershed modeling approach. We developed alternative models of varying complexity for <span class="hlt">sediment</span> production and <span class="hlt">transport</span> at the network scale driven by hydrologic forcing. We simulate <span class="hlt">sediment</span> supply and <span class="hlt">transport</span> in tributaries upstream of the dam. The modeled <span class="hlt">sediment</span> supply and <span class="hlt">transport</span> dynamics are based on calibrated formulae (e.g., bedload <span class="hlt">transport</span> is simulated using Wilcock-Crowe 2003 with modification based on observed bedload <span class="hlt">transport</span> in the Elwha River). Observational data that aid in our approach include DEM, channel morphology, meteorology, and streamflow and <span class="hlt">sediment</span> (bedload and suspended load) discharge. We aim to demonstrate how the observed <span class="hlt">sediment</span> yield behind the dams was influenced by upstream <span class="hlt">transport</span> supply and capacity limitations, thereby demonstrating the scale effects of flow and <span class="hlt">sediment</span> <span class="hlt">transport</span> processes in the Elwha River</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017FrES..tmp...75L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017FrES..tmp...75L"><span>Coarse and fine <span class="hlt">sediment</span> <span class="hlt">transportation</span> patterns and causes downstream of the Three Gorges Dam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Songzhe; Yang, Yunping; Zhang, Mingjin; Sun, Zhaohua; Zhu, Lingling; You, Xingying; Li, Kanyu</p> <p>2017-11-01</p> <p>Reservoir construction within a basin affects the process of water and <span class="hlt">sediment</span> <span class="hlt">transport</span> downstream of the dam. The Three Gorges Reservoir (TGR) affects the <span class="hlt">sediment</span> <span class="hlt">transport</span> downstream of the dam. The impoundment of the TGR reduced total downstream <span class="hlt">sediment</span>. The <span class="hlt">sediment</span> group d≤0.125 mm (fine particle) increased along the path, but the average was still below what existed before the reservoir impoundment. The <span class="hlt">sediments</span> group d>0.125 mm (coarse particle) was recharged in the Yichang to Jianli reach, but showed a deposition trend downstream of Jianli. The coarse <span class="hlt">sediment</span> in the Yichang to Jianli section in 2003 to 2007 was above the value before the TGR impoundment. However, the increase of both coarse and fine <span class="hlt">sediments</span> in 2008 to 2014 was less than that in 2003 to 2007. The <span class="hlt">sediment</span> retained in the dam is the major reason for the <span class="hlt">sediment</span> reduction downstream. However, the retention in different river reaches is affected by riverbed coarsening, discharge, flow process, and conditions of lake functioning and recharging from the tributaries. The main conclusions derived from our study are as follows: 1) The riverbed in the Yichang to Shashi section was relatively coarse, thereby limiting the supply of fine and coarse <span class="hlt">sediments</span>. The fine <span class="hlt">sediment</span> supply was mainly controlled by TGR discharge, whereas the coarse <span class="hlt">sediment</span> supply was controlled by the duration of high flow and its magnitude. 2) The supply of both coarse and fine <span class="hlt">sediments</span> in the Shashi to Jianli section was controlled by the amount of total discharge. The <span class="hlt">sediment</span> supply from the riverbed was higher in flood years than that in the dry years. The coarse <span class="hlt">sediment</span> tended to deposit, and the deposition in the dry years was larger than that in the flood years. 3) The feeding of the fine <span class="hlt">sediment</span> in the Luoshan to Hankou section was mainly from the riverbed. The supply in 2008 to 2014 was more than that in 2003 to 2007. Around 2010, the coarse <span class="hlt">sediments</span> transited from depositing to scouring that was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JHyd..289..190S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JHyd..289..190S"><span>Streamflow, <span class="hlt">sediment</span> and carbon <span class="hlt">transport</span> from a Himalayan watershed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharma, P.; Rai, S. C.</p> <p>2004-04-01</p> <p>Rivers indeed serve an important role in the carbon fluxes being recognized as a major component to regional and global environmental change. The present study focuses the <span class="hlt">sediment</span> and carbon <span class="hlt">transports</span> in a Himalayan watershed (elevational range 300-2650 m asl, area of 3014 ha) at Sikkim, India. The watershed has five perennial streams, all attain significant size during rainy season. The micro-watershed for each perennial stream has a mosaic distribution of land-use practices, viz. forests, agroforestry, agriculture and wastelands. The average discharge in the Rinjikhola, the watershed outlet was 840-850 l s -1 in summer season that increased by 5-6 times in rainy season. <span class="hlt">Sediment</span> concentration varied distinctly with seasons in different streams and the outlet of the watershed. The soil loss rate from the total watershed ranged from 6 to 7 t ha -1 yr -1 that accounts to a net loss of 833 t yr -1 organic carbon, and 2025 t yr -1 dissolved organic carbon from the watershed, and more than 90% of soil losses were attributable to open cropped area. The stream discharge, soil and carbon loss and precipitation partitioning through different pathways in forest and agroforestry land-use suggest that these land-uses promote conservation of soil and carbon. It is emphasized that a good understanding of carbon transfer through overland flow and discharge is important for policy decisions and management of soil and carbon loss of a Himalayan watershed as it is very sensitive to land-use/cover changes. Therefore, the conversion of forest to agricultural land should be reversed. Agroforestry systems should be included in agricultural land in mountainous regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP13A0840B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP13A0840B"><span>Turbulence and <span class="hlt">sediment</span> <span class="hlt">transport</span> over sand dunes and ripples</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bennis, A.; Le Bot, S.; lafite, R.; Bonneton, P.; Ardhuin, F.</p> <p>2013-12-01</p> <p>Several bedforms are present near to the surfzone of natural beaches. Dunes and ripples are frequently observed. Understanding the turbulence over these forms is essential for the <span class="hlt">sediment</span> <span class="hlt">transport</span>. The turbulent flow and the suspended sand particles interact with each other. At the moment, the modelling strategy for turbulence is still a challenge. According to the spatial scales, some different methods to model the turbulence are employed, in particular the RANS (Reynolds Averaged Navier-Stokes) and the LES (Large Eddy Simulation). A hybrid method combining both RANS and LES is set up here. We have adapted this method, initially developed for atmospheric flow, to the oceanic flow. This new method is implemented inside the 3D hydrodynamic model, MARS 3D, which is forced by waves. LES is currently the best way to simulate turbulent flow but its higher cost prevents it from being used for large scale applications. So, here we use RANS near the bottom while LES is set elsewhere. It allows us minimize the computational cost and ensure a better accuracy of the results than with a fully RANS model. In the case of megaripples, the validation step was performed with two sets of field data (Sandy Duck'97 and Forsoms'13) but also with the data from Dune2D model which uses only RANS for turbulence. The main findings are: a) the vertical profiles of the velocity are similar throughout the data b) the turbulent kinetic energy, which was underestimated by Dune2D, is in line with the observations c) the concentration of the suspended <span class="hlt">sediment</span> is simulated with a better accuracy than with Dune2D but this remains lower than the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2006/1318/of2006-1318.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2006/1318/of2006-1318.pdf"><span>Deschutes estuary feasibility study: hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>George, Douglas A.; Gelfenbaum, Guy; Lesser, Giles; Stevens, Andrew W.</p> <p>2006-01-01</p> <p>- Provide the completed study to the CLAMP Steering Committee so that a recommendation about a long-term aquatic environment of the basin can be made. The hydrodynamic and <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling task developed a number of different model simulations using a process-based morphological model, Delft3D, to help address these goals. Modeling results provide a qualitative assessment of estuarine behavior both prior to dam construction and after various post-dam removal scenarios. Quantitative data from the model is used in the companion biological assessment and engineering design components of the overall study. Overall, the modeling study found that after dam removal, tidal and estuarine processes are immediately restored, with marine water from Budd Inlet carried into North and Middle Basin on each rising tide and mud flats being exposed with each falling tide. Within the first year after dam removal, tidal processes, along with the occasional river floods, act to modify the estuary bed by redistributing <span class="hlt">sediment</span> through erosion and deposition. The morphological response of the bed is rapid during the first couple of years, then slows as a dynamic equilibrium is reached within three to five years. By ten years after dam removal, the overall hydrodynamic and morphologic behavior of the estuary is similar to the pre-dam estuary, with the exception of South Basin, which has been permanently modified by human activities. In addition to a qualitative assessment of estuarine behavior, process-based modeling provides the ability address specific questions to help to inform decision-making. Considering that predicting future conditions of a complex estuarine environment is wrought with uncertainties, quantitative results in this report are often expressed in terms of ranges of possible outcomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511959S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511959S"><span>Quantifying fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> in a mountain catchment (Schöttlbach, Styria) using <span class="hlt">sediment</span> impact sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stangl, Johannes; Sass, Oliver; Schneider, Josef; Harb, Gabriele</p> <p>2013-04-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> in river systems, being the output of geomorphic processes in the catchment, is a recurrent problem for geomorphological <span class="hlt">sediment</span> budget studies, natural hazard assessment and river engineering. <span class="hlt">Sediment</span> budgets of alpine catchments are likely to be modified by changing total precipitation and the probability of heavy precipitation events in the context of climate change, even if projections of precipitation change for Austria and the entire Alpine region are still very uncertain. Effective <span class="hlt">sediment</span> management requires profound knowledge on the <span class="hlt">sediment</span> cascade in the head-waters. However, bedload measurements at alpine rivers or torrents are rare; in Styria, they are altogether missing. Due to a three hour heavy rainfall event on 07-Jul 2011, which caused cata-strophic flooding with massive damage in the city of Oberwölz and its surrounding, we chose the catchment area of the Schöttlbach in the upper Mur river valley in Styria (Austria) as our study area. In the framework of the ClimCatch project, we intend to develop a conceptual model of coupled and decoupled <span class="hlt">sediment</span> routing to quantify the most prominent <span class="hlt">sediment</span> fluxes and <span class="hlt">sediment</span> sinks, combining up-to-date geomorphological and river engineering techniques. Repeated Airborne Laser Scans will provide an overview of ongoing processes, diachronous TLS surveys (cut-and-fill analysis), ground-penetrating radar and 2D-geoelectric surveys should quantity the most important mass fluxes on the slopes and in the channels and derive a quantitative <span class="hlt">sediment</span> budget, including the volume of temporary <span class="hlt">sediment</span> stores. Besides quantifying slope processes, <span class="hlt">sediment</span> sinks and total <span class="hlt">sediment</span> output, the <span class="hlt">sediment</span> <span class="hlt">trans-port</span> in the torrents is of particular interest. We use <span class="hlt">sediment</span> impact sensors (SIS) which were in-stalled in several river sections in the main stretch of the Schöttlbach and in its tributaries. The SIS mainly consists of two parts connected by a coated cable, the steel shell with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9628S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9628S"><span>Temporal pattern and memory in <span class="hlt">sediment</span> <span class="hlt">transport</span> in an experimental step-pool channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saletti, Matteo; Molnar, Peter; Zimmermann, André; Hassan, Marwan A.; Church, Michael; Burlando, Paolo</p> <p>2015-04-01</p> <p>In this work we study the complex dynamics of <span class="hlt">sediment</span> <span class="hlt">transport</span> and bed morphology in steep streams, using a dataset of experiments performed in a steep flume with natural <span class="hlt">sediment</span>. High-resolution (1 sec) time series of <span class="hlt">sediment</span> <span class="hlt">transport</span> were measured for individual size classes at the outlet of the flume for different combinations of <span class="hlt">sediment</span> input rates, discharges, and flume slopes. The data show that the relation between instantaneous discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> exhibits large variability on different levels. After dividing the time series into segments of constant water discharge, we quantify the statistical properties of <span class="hlt">transport</span> rates by fitting the data with a Generalized Extreme Value distribution, whose 3 parameters are related to the average <span class="hlt">sediment</span> flux. We analyze separately extreme events of <span class="hlt">transport</span> rate in terms of their fractional composition; if only events of high magnitude are considered, coarse grains become the predominant component of the total <span class="hlt">sediment</span> yield. We quantify the memory in grain size dependent <span class="hlt">sediment</span> <span class="hlt">transport</span> with variance scaling and autocorrelation analyses; more specifically, we study how the variance changes with different aggregation scales and how the autocorrelation coefficient changes with different time lags. Our results show that there is a tendency to an infinite memory regime in <span class="hlt">transport</span> rate signals, which is limited by the intermittency of the largest fractions. Moreover, the structure of memory is both grain size-dependent and magnitude-dependent: temporal autocorrelation is stronger for small grain size fractions and when the average <span class="hlt">sediment</span> <span class="hlt">transport</span> rate is large. The short-term memory in coarse grain <span class="hlt">transport</span> increases with temporal aggregation and this reveals the importance of the sampling frequency of bedload <span class="hlt">transport</span> rates in natural streams, especially for large fractions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/unnumbered/70175282/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/unnumbered/70175282/report.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> in Streams in the Umpqua River Basin, Oregon</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Onions, C. A.</p> <p>1969-01-01</p> <p>This report presents tables of suspended-<span class="hlt">sediment</span> data collected from 1956 to 1967 at 10 sites in the Umpqua River basin. Computations based on these data indicate that average annual suspended-<span class="hlt">sediment</span> yields at these sites range from 137 to 822 tons per square mile. Because available data for the Umpqua River basin are generally inadequate for accurate determinations of <span class="hlt">sediment</span> yield and for the definition of characteristics of fluvial <span class="hlt">sediments</span>, recommendations are made for the collection and analysis of additional <span class="hlt">sediment</span> data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1918137B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918137B"><span>Implications of <span class="hlt">sediment</span> <span class="hlt">transport</span> by subglacial water flow for interpreting contemporary glacial erosion rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beaud, Flavien; Flowers, Gwenn E.; Venditti, Jeremy G.</p> <p>2017-04-01</p> <p>The role of glaciers in landscape evolution is central to the interactions between climate and tectonic forces at high latitudes and in mountainous regions. <span class="hlt">Sediment</span> yields from glacierized basins are used to quantify contemporary erosion rates on seasonal to decadal timescales, often under the assumption that subglacial water flow is the main contributor to these yields. Two recent studies have furthermore used such <span class="hlt">sediment</span> fluxes to calibrate a glacial erosion rule, where erosion rate scales with ice sliding speed raised to a power greater than one. Subglacial <span class="hlt">sediment</span> <span class="hlt">transport</span> by water flow has however seldom been studied, thus the controls on <span class="hlt">sediment</span> yield from glacierized basins remain enigmatic. To bridge this gap, we develop a 1-D model of morphodynamics in semi-circular bedrock-floored subglacial channels. We adapt a <span class="hlt">sediment</span> conservation law from the fluvial literature, developed for both mixed bedrock / alluvial and alluvial conditions, to subglacial channels. Channel evolution is a function of the traditional melt-opening due to viscous heat dissipation from the water flow, and creep closure of the overlying ice, to which we add the closure or enlargement due to <span class="hlt">sediment</span> deposition or removal, respectively. Using a simple ice geometry representing a land-terminating glacier, we find that the shear stresses produced by the water flow on the bed decrease significantly near the terminus. As the ice thins, creep closure decreases and large hydraulic potential gradients cannot be sustained. The resulting gradients in <span class="hlt">sediment</span> <span class="hlt">transport</span> lead to a bottleneck, and <span class="hlt">sediment</span> accumulates if the <span class="hlt">sediment</span> supply is adequate. A similar bottleneck occurs if a channel is well established and water discharge drops. Whether such constriction happens in space of time, in the presence of a sufficiently large <span class="hlt">sediment</span> supply <span class="hlt">sediment</span> accumulates temporarily near the terminus, followed shortly thereafter by enhanced <span class="hlt">sediment</span> <span class="hlt">transport</span>. Reduction in the cross-sectional area</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wsp/2349/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wsp/2349/report.pdf"><span>The significance of <span class="hlt">sediment</span> <span class="hlt">transport</span> in arroyo development</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Meyer, David F.</p> <p>1989-01-01</p> <p> monitored through time indicate that the rate of arroyo widening is dependent on the amount of bedload <span class="hlt">transported</span> through a reach. This is documented by the relations between the rate of arroyo erosion and the observed <span class="hlt">sediment</span> <span class="hlt">transport</span>, the channel slope, the channel width and the channel width-to-depth ratio. When a small amount of bed material is being <span class="hlt">transported</span>, arroyos do not widen whether they are narrow (arroyo width-to-depth ratios between 1.5 and 3.1), intermediate (between 2.5 and 4.8), or wide (greater than 4.9). Arroyo widening resumes when a larger supply of bed material is introduced. Arroyo widening decreases through time because with progressive increases of arroyo width, the frequency with which unstable channels within the arroyo impinge upon arroyo walls decreases. Arroyos become wider in a downstream direction in response to the cumulative effect of upstream <span class="hlt">sediment</span> production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/1007660','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/1007660"><span>Stochastic model for the long-term <span class="hlt">transport</span> of stored <span class="hlt">sediment</span> in a river channel</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kelsey, Harvey M.; Lamberson, Roland; Madej, Mary Ann</p> <p>1987-01-01</p> <p>We develop a stochastic model for the <span class="hlt">transport</span> of stored <span class="hlt">sediment</span> down a river channel. The model is based on probabilities of transition of particles among four different <span class="hlt">sediment</span> storage reservoirs, called active (often mobilized), semiactive, inactive, and stable (hardly ever mobilized). The probabilities are derived from computed <span class="hlt">sediment</span> residence times. Two aspects of <span class="hlt">sediment</span> storage are investigated: flushing times of <span class="hlt">sediment</span> out of a storage reservoir and changes in the quantity of <span class="hlt">sediment</span> stored in different reservoirs due to seasonal <span class="hlt">sediment</span> <span class="hlt">transport</span> into, and out of, a reach. We apply the model to Redwood Creek, a gravel bed river in northern California. Although the Redwood Creek data set is incomplete, the application serves as an example of the sorts of analyses that can be done with the method. The application also provides insights into the <span class="hlt">sediment</span> storage process. <span class="hlt">Sediment</span> flushing times are highly dependent on the degree of interaction of the stable reservoir with the more mobile <span class="hlt">sediment</span> reservoirs. The most infrequent and highest intensity storm events, which mobilize the stable reservoir, are responsible for the long-term shifts in <span class="hlt">sediment</span> storage. Turnover times of channel <span class="hlt">sediment</span> in all but the stable reservoir are on the order of 750 years, suggesting this is all the time needed for thorough interchange between these <span class="hlt">sediment</span> compartments and cycling of most <span class="hlt">sediment</span> particles from the initial reservoir to the ocean. Finally, the Markov model has adequately characterized <span class="hlt">sediment</span> storage changes in Redwood Creek for 1947–1982, especially for the active reservoir. The model replicates field observation of the passage of a slug of <span class="hlt">sediment</span> through the active reservoir of the middle reach of Redwood Creek in the 18 years following a major storm in 1964 that introduced large quantities of landslide debris to the channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2008/5093/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2008/5093/"><span>Simulation of Flow, <span class="hlt">Sediment</span> <span class="hlt">Transport</span>, and <span class="hlt">Sediment</span> Mobility of the Lower Coeur d'Alene River, Idaho</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Berenbrock, Charles; Tranmer, Andrew W.</p> <p>2008-01-01</p> <p>A one-dimensional <span class="hlt">sediment-transport</span> model and a multi-dimensional hydraulic and bed shear stress model were developed to investigate the hydraulic, <span class="hlt">sediment</span> <span class="hlt">transport</span>, and <span class="hlt">sediment</span> mobility characteristics of the lower Coeur d?Alene River in northern Idaho. This report documents the development and calibration of those models, as well as the results of model simulations. The one-dimensional <span class="hlt">sediment-transport</span> model (HEC-6) was developed, calibrated, and used to simulate flow hydraulics and erosion, deposition, and <span class="hlt">transport</span> of <span class="hlt">sediment</span> in the lower Coeur d?Alene River. The HEC-6 modeled reach, comprised of 234 cross sections, extends from Enaville, Idaho, on the North Fork of the Coeur d?Alene River and near Pinehurst, Idaho, on the South Fork of the river to near Harrison, Idaho, on the main stem of the river. Bed-<span class="hlt">sediment</span> samples collected by previous investigators and samples collected for this study in 2005 were used in the model. <span class="hlt">Sediment</span> discharge curves from a previous study were updated using suspended-<span class="hlt">sediment</span> samples collected at three sites since April 2000. The HEC-6 was calibrated using river discharge and water-surface elevations measured at five U.S. Geological Survey gaging stations. The calibrated HEC-6 model allowed simulation of management alternatives to assess erosion and deposition from proposed dredging of contaminated streambed <span class="hlt">sediments</span> in the Dudley reach. Four management alternatives were simulated with HEC-6. Before the start of simulation for these alternatives, seven cross sections in the reach near Dudley, Idaho, were deepened 20 feet?removing about 296,000 cubic yards of <span class="hlt">sediments</span>?to simulate dredging. Management alternative 1 simulated stage-discharge conditions from 2000, and alternative 2 simulated conditions from 1997. Results from alternatives 1 and 2 indicated that about 6,500 and 12,300 cubic yards, respectively, were deposited in the dredged reach. These figures represent 2 and 4 percent, respectively, of the total volume of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDA10008S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDA10008S"><span>Laboratory Experiments Modelling <span class="hlt">Sediment</span> <span class="hlt">Transport</span> by River Plumes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sutherland, Bruce; Gingras, Murray; Knudson, Calla; Steverango, Luke; Surma, Chris</p> <p>2016-11-01</p> <p>Through lock-release laboratory experiments, the <span class="hlt">transport</span> of particles by hypopycnal (surface) currents is examined as they flow into a uniform-density and a two-layer ambient fluid. In most cases the tank is tilted so that the current flows over a slope representing an idealization of a <span class="hlt">sediment</span>-bearing river flowing into the ocean and passing over the continental shelf. When passing into a uniform-density ambient, the hypopycnal current slows and stops as particles rain out, carrying some of the light interstitial fluid with them. Rather than settling on the bottom, in many cases the descending particles accumulate to form a hyperpycnal (turbidity) current that flows downslope. This current then slows and stops as particles both rain out to the bottom and also rise again to the surface, carried upward by the light interstitial fluid. For a hypopycnal current flowing into a two-layer fluid, the current slows as particles rain out and accumulate at the interface of the two-layer ambient. Eventually these particles penetrate through the interface and settle to the bottom with no apparent formation of a hyperpycnal current. Analyses are performed to characterize the speed of the currents and stopping distances as they depend upon experiment parameters. Natural Sciences and Engineering Research Council.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997CSR....17..337L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997CSR....17..337L"><span>Acoustical and optical backscatter measurements of <span class="hlt">sediment</span> <span class="hlt">transport</span> in the 1988 1989 STRESS experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lynch, J. F.; Gross, T. F.; Sherwood, C. R.; Irish, J. D.; Brumley, B. H.</p> <p>1997-04-01</p> <p>During the 1988-1989 <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Events on Shelves and Slopes (STRESS) experiment, a 1-MHz acoustic backscatter system (ABSS), deployed in 90 m of water off the California coast measured vertical profiles of suspended <span class="hlt">sediment</span> concentration from 1.5 to (nominally) 26 meters above bottom (m.a.b.). An 8-week-long time series was obtained, showing major <span class="hlt">sediment</span> <span class="hlt">transport</span> events (storms) in late December and early January. Comparison of the acoustics measurements from 1.5 m.a.b. are made with optical backscatter system (OBS) concentration estimates lower in the boundary layer (0.25 m.a.b.). Correlations between ABSS and OBS concentration measurements and the boundary layer forcing functions (waves, currents, and their non-linear interaction) provided a variety of insights into the nature of the <span class="hlt">sediment</span> <span class="hlt">transport</span> of the STRESS site. <span class="hlt">Transport</span> rates and integrated <span class="hlt">transport</span> are seen to be dominated by the largest storm events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4575G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4575G"><span>Dispersal and <span class="hlt">transport</span> of river <span class="hlt">sediment</span> on the Catalan Shelf (NW Mediterranean Sea).</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grifoll, Manel; Gracia, Vicente; Espino, Manuel; Sánchez-Arcilla, Agustín</p> <p>2014-05-01</p> <p>A three-dimensional coupled hydrodynamics-<span class="hlt">sediment</span> <span class="hlt">transport</span> model for the Catalan shelf (NW Mediterranean Sea) is implemented and used to represent the fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> and depositional patterns. The modelling system COAWST (Warner et al., 2010) allows to exchange field from the water circulation model ROMS and the wave model SWAN including combined wave-current bed stress and both <span class="hlt">sediment</span> <span class="hlt">transport</span> mechanisms: bed and suspended load. Two rivers surrounding Barcelona harbour are considered in the numerical experiments. Different temporal and spatial scales are modelled in order to evaluate physical mechanisms such as: fine deposits formation in the inner-shelf, harbour siltation or <span class="hlt">sediment</span> exporting to the outer shelf. Short-time simulations in a high-resolution mesh have been used to reproduce the initial stages of the <span class="hlt">sediment</span> dispersal. In this case, <span class="hlt">sediment</span> accumulation occurs confined in an area attached to the coastline. A subsequent reworking is observed due to the wave-induced bottom stresses which resuspend fine material exported then towards the mid-shelf by seawards fluxes. The long-term water circulation simulations explains the observed fine deposits over the shelf. The results provide knowledge of <span class="hlt">sediment</span> <span class="hlt">transport</span> processes in the near-shore area of a micro-tidal domain. REFERENCES: Warner, J.C., Armstrong, B., He, R., and Zambon, J.B., 2010, Development of a Coupled Ocean-Atmosphere-Wave-<span class="hlt">Sediment</span> <span class="hlt">Transport</span> (COAWST) modeling system: Ocean Modeling, v. 35, no. 3, p. 230-244.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMEP43A0654Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMEP43A0654Y"><span>Reconstruction of <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways in modern microtidal sand flat by multiple classification analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamashita, S.; Nakajo, T.; Naruse, H.</p> <p>2009-12-01</p> <p>In this study, we statistically classified the grain size distribution of the bottom surface <span class="hlt">sediment</span> on a microtidal sand flat to analyze the depositional processes of the <span class="hlt">sediment</span>. Multiple classification analysis revealed that two types of <span class="hlt">sediment</span> populations exist in the bottom surface <span class="hlt">sediment</span>. Then, we employed the <span class="hlt">sediment</span> trend model developed by Gao and Collins (1992) for the estimation of <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways. As a result, we found that statistical discrimination of the bottom surface <span class="hlt">sediment</span> provides useful information for the <span class="hlt">sediment</span> trend model while dealing with various types of <span class="hlt">sediment</span> <span class="hlt">transport</span> processes. The microtidal sand flat along the Kushida River estuary, Ise Bay, central Japan, was investigated, and 102 bottom surface <span class="hlt">sediment</span> samples were obtained. Then, their grain size distribution patterns were measured by the settling tube method, and each grain size distribution parameter (mud and gravel contents, mean grain size, coefficient of variance (CV), skewness, kurtosis, 5, 25, 50, 75, and 95 percentile) was calculated. Here, CV is the normalized sorting value divided by the mean grain size. Two classical statistical methods—principal component analysis (PCA) and fuzzy cluster analysis—were applied. The results of PCA showed that the bottom surface <span class="hlt">sediment</span> of the study area is mainly characterized by grain size (mean grain size and 5-95 percentile) and the CV value, indicating predominantly large absolute values of factor loadings in primal component (PC) 1. PC1 is interpreted as being indicative of the grain-size trend, in which a finer grain-size distribution indicates better size sorting. The frequency distribution of PC1 has a bimodal shape and suggests the existence of two types of <span class="hlt">sediment</span> populations. Therefore, we applied fuzzy cluster analysis, the results of which revealed two groupings of the <span class="hlt">sediment</span> (Cluster 1 and Cluster 2). Cluster 1 shows a lower value of PC1, indicating coarse and poorly sorted <span class="hlt">sediments</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2352H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2352H"><span>Characterization of <span class="hlt">bed</span> <span class="hlt">load</span> discharge in unsteady flow events in an ephemeral channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Halfi, Eran</p> <p>2017-04-01</p> <p>There are many methods and equations for estimating bedload flux in steady flow conditions. Yet, very little is known about the effect of very unsteady flows, such as flash floods, on bedload flux. The unpredictable nature of the floods together with many logistic difficulties and safety issues in monitoring explain this gap in knowledge. Global climate change may increase flood event occurrence, making their understanding even more crucial. This research focuses on two durations of flash floods where the flow is most rapidly changing: a) flash flood bore arriving on dry river bed and b) flash flood bore arriving on a column of moving water. The methodology of our study is based on the demonstrated ability of the Eshtemoa gauging station to automatically monitor the variation of bedload flux depending on flow and bed characteristics, along with innovative equipment including hydrophones and geophones for capturing acoustic signals of bedload <span class="hlt">sediments</span> (1 Hz), video cameras for continuous monitoring of water surface velocity (by the LSPIV method to determine its structure and velocity) and 3-D velocimetry for characterizing turbulence (40 Hz). Additional to these, a well-planned deployment was carried out, including alerting sensors and cellular transmission, enabling to be onsite when bores arrive. During the winter of 2015-2016 two flow events were sufficiently large to <span class="hlt">transport</span> significant amounts of bedload; the magnitude of the larger event occurs once in a few years. Calibration between the acoustic indirect sensor and the direct slot sampler allow determination of bedload flux at a frequency of 1 Hz. Analyses of the two events indicate an increase of the turbulent nature (increase of the turbulent kinetic energy and the instantaneous vertical velocities), shear stress and bedload flux during the rising limb in the first two minutes of bore arrival.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHyd..541..902A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHyd..541..902A"><span>Past, present and prospect of an Artificial Intelligence (AI) based model for <span class="hlt">sediment</span> <span class="hlt">transport</span> prediction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Afan, Haitham Abdulmohsin; El-shafie, Ahmed; Mohtar, Wan Hanna Melini Wan; Yaseen, Zaher Mundher</p> <p>2016-10-01</p> <p>An accurate model for <span class="hlt">sediment</span> prediction is a priority for all hydrological researchers. Many conventional methods have shown an inability to achieve an accurate prediction of suspended <span class="hlt">sediment</span>. These methods are unable to understand the behaviour of <span class="hlt">sediment</span> <span class="hlt">transport</span> in rivers due to the complexity, noise, non-stationarity, and dynamism of the <span class="hlt">sediment</span> pattern. In the past two decades, Artificial Intelligence (AI) and computational approaches have become a remarkable tool for developing an accurate model. These approaches are considered a powerful tool for solving any non-linear model, as they can deal easily with a large number of data and sophisticated models. This paper is a review of all AI approaches that have been applied in <span class="hlt">sediment</span> modelling. The current research focuses on the development of AI application in <span class="hlt">sediment</span> <span class="hlt">transport</span>. In addition, the review identifies major challenges and opportunities for prospective research. Throughout the literature, complementary models superior to classical modelling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Geomo.296...59G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Geomo.296...59G"><span>Importance of measuring discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> in lesser tributaries when closing <span class="hlt">sediment</span> budgets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Griffiths, Ronald E.; Topping, David J.</p> <p>2017-11-01</p> <p><span class="hlt">Sediment</span> budgets are an important tool for understanding how riverine ecosystems respond to perturbations. Changes in the quantity and grain size distribution of <span class="hlt">sediment</span> within river systems affect the channel morphology and related habitat resources. It is therefore important for resource managers to know if a river reach is in a state of <span class="hlt">sediment</span> accumulation, deficit or stasis. Many <span class="hlt">sediment</span>-budget studies have estimated the <span class="hlt">sediment</span> loads of ungaged tributaries using regional <span class="hlt">sediment</span>-yield equations or other similar techniques. While these approaches may be valid in regions where rainfall and geology are uniform over large areas, use of <span class="hlt">sediment</span>-yield equations may lead to poor estimations of loads in regions where rainfall events, contributing geology, and vegetation have large spatial and/or temporal variability. Previous estimates of the combined mean-annual <span class="hlt">sediment</span> load of all ungaged tributaries to the Colorado River downstream from Glen Canyon Dam vary by over a factor of three; this range in estimated <span class="hlt">sediment</span> loads has resulted in different researchers reaching opposite conclusions on the sign (accumulation or deficit) of the <span class="hlt">sediment</span> budget for particular reaches of the Colorado River. To better evaluate the supply of fine <span class="hlt">sediment</span> (sand, silt, and clay) from these tributaries to the Colorado River, eight gages were established on previously ungaged tributaries in Glen, Marble, and Grand canyons. Results from this <span class="hlt">sediment</span>-monitoring network show that previous estimates of the annual <span class="hlt">sediment</span> loads of these tributaries were too high and that the <span class="hlt">sediment</span> budget for the Colorado River below Glen Canyon Dam is more negative than previously calculated by most researchers. As a result of locally intense rainfall events with footprints smaller than the receiving basin, floods from a single tributary in semi-arid regions can have large (≥ 10 ×) differences in <span class="hlt">sediment</span> concentrations between equal magnitude flows. Because <span class="hlt">sediment</span> loads do not</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70190551','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70190551"><span>Importance of measuring discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> in lesser tributaries when closing <span class="hlt">sediment</span> budgets</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Griffiths, Ronald; Topping, David</p> <p>2017-01-01</p> <p><span class="hlt">Sediment</span> budgets are an important tool for understanding how riverine ecosystems respond to perturbations. Changes in the quantity and grain size distribution of <span class="hlt">sediment</span> within river systems affect the channel morphology and related habitat resources. It is therefore important for resource managers to know if a river reach is in a state of <span class="hlt">sediment</span> accumulation, deficit or stasis. Many <span class="hlt">sediment</span>-budget studies have estimated the <span class="hlt">sediment</span> loads of ungaged tributaries using regional <span class="hlt">sediment</span>-yield equations or other similar techniques. While these approaches may be valid in regions where rainfall and geology are uniform over large areas, use of <span class="hlt">sediment</span>-yield equations may lead to poor estimations of loads in regions where rainfall events, contributing geology, and vegetation have large spatial and/or temporal variability.Previous estimates of the combined mean-annual <span class="hlt">sediment</span> load of all ungaged tributaries to the Colorado River downstream from Glen Canyon Dam vary by over a factor of three; this range in estimated <span class="hlt">sediment</span> loads has resulted in different researchers reaching opposite conclusions on the sign (accumulation or deficit) of the <span class="hlt">sediment</span> budget for particular reaches of the Colorado River. To better evaluate the supply of fine <span class="hlt">sediment</span> (sand, silt, and clay) from these tributaries to the Colorado River, eight gages were established on previously ungaged tributaries in Glen, Marble, and Grand canyons. Results from this <span class="hlt">sediment</span>-monitoring network show that previous estimates of the annual <span class="hlt">sediment</span> loads of these tributaries were too high and that the <span class="hlt">sediment</span> budget for the Colorado River below Glen Canyon Dam is more negative than previously calculated by most researchers. As a result of locally intense rainfall events with footprints smaller than the receiving basin, floods from a single tributary in semi-arid regions can have large (≥ 10 ×) differences in <span class="hlt">sediment</span> concentrations between equal magnitude flows. Because <span class="hlt">sediment</span> loads do not</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014WRR....50.7900S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014WRR....50.7900S"><span>Physical context for theoretical approaches to <span class="hlt">sediment</span> <span class="hlt">transport</span> magnitude-frequency analysis in alluvial channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sholtes, Joel; Werbylo, Kevin; Bledsoe, Brian</p> <p>2014-10-01</p> <p>Theoretical approaches to magnitude-frequency analysis (MFA) of <span class="hlt">sediment</span> <span class="hlt">transport</span> in channels couple continuous flow probability density functions (PDFs) with power law flow-<span class="hlt">sediment</span> <span class="hlt">transport</span> relations (rating curves) to produce closed-form equations relating MFA metrics such as the effective discharge, Qeff, and fraction of <span class="hlt">sediment</span> <span class="hlt">transported</span> by discharges greater than Qeff, f+, to statistical moments of the flow PDF and rating curve parameters. These approaches have proven useful in understanding the theoretical drivers behind the magnitude and frequency of <span class="hlt">sediment</span> <span class="hlt">transport</span>. However, some of their basic assumptions and findings may not apply to natural rivers and streams with more complex flow-<span class="hlt">sediment</span> <span class="hlt">transport</span> relationships or management and design scenarios, which have finite time horizons. We use simple numerical experiments to test the validity of theoretical MFA approaches in predicting the magnitude and frequency of <span class="hlt">sediment</span> <span class="hlt">transport</span>. Median values of Qeff and f+ generated from repeated, synthetic, finite flow series diverge from those produced with theoretical approaches using the same underlying flow PDF. The closed-form relation for f+ is a monotonically increasing function of flow variance. However, using finite flow series, we find that f+ increases with flow variance to a threshold that increases with flow record length. By introducing a <span class="hlt">sediment</span> entrainment threshold, we present a physical mechanism for the observed diverging relationship between Qeff and flow variance in fine and coarse-bed channels. Our work shows that through complex and threshold-driven relationships <span class="hlt">sediment</span> <span class="hlt">transport</span> mode, channel morphology, flow variance, and flow record length all interact to influence estimates of what flow frequencies are most responsible for <span class="hlt">transporting</span> <span class="hlt">sediment</span> in alluvial channels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA531009','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA531009"><span><span class="hlt">Transport</span> of Gas and Solutes in Permeable Estuarine <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-01-01</p> <p>seagrass . 2) To quantify the size range and composition of the gas bubbles in the <span class="hlt">sediment</span> and the overlying water. 3) To determine the volume change and...from sand containing natural bubbles produced by photosynthesis and control <span class="hlt">sediment</span> without bubbles. Set up of the pressure tank experiments. The...above the tank will permit bubble growth in the incubated <span class="hlt">sediment</span> by photosynthesis . RESULTS Fieldwork and bubble production. At CML, ample bubbles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA572766','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA572766"><span><span class="hlt">Transport</span> of Gas and Solutes in Permeable Estuarine <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-09-30</p> <p>produce his Ph.D. dissertation based on this reserach . The acoustic method for detecting and measuring small gas bubbles in marine sands. This...the detection and quantification of small free gas volumes in sandy coastal <span class="hlt">sediments</span>. After introducing and explaining the instrument, the paper ...influence the <span class="hlt">sediment</span> erosion threshold, biogeochemical zonations, living space for organisms and thereby the role of the <span class="hlt">sediments</span> in the cycles of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H31E1045W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H31E1045W"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> and Deposition Resulting from a Dam-Removal <span class="hlt">Sediment</span> Pulse: Milltown Dam, Clark Fork River, MT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilcox, A. C.</p> <p>2010-12-01</p> <p>The removal of Milltown Dam in 2008 from the Clark Fork River, Montana, USA, lowered base level at the dam site by 9 m and triggered erosion of nearly 600,000 metric tons of predominantly fine reservoir <span class="hlt">sediment</span>. Bedload and bed-material sampling, repeat topographic surveys, <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling, geochemical fingerprinting of downstream <span class="hlt">sediments</span>, and Lidar analysis have all been applied to study the upstream and downstream effects of the dam removal. In the years since dam breaching, successive years with similar peak flows (3-year recurrence interval) were followed by a third year with below-average runoff. Nearly all of the documented reservoir erosion occurred in the first year, when sand and silt was eroded and <span class="hlt">transported</span> downstream. In subsequent years, minimal reservoir erosion occurred, in part as a result of active management to prevent further reservoir erosion, but coarse material eroded from the reservoir has dispersed downstream. Upstream responses in this system have been strongly mediated by Superfund remediation activities in Milltown Reservoir, in which over two million metric tons of contaminated <span class="hlt">sediments</span> have been mechanically excavated. Downstream aggradation has been limited in the main channel but was initially substantial in bars and side channels of a multi-thread reach 21 to 25 km downstream of the dam site, suggesting that channel change has been influenced far more by the antecedent depositional environment than by proximity to the source of the <span class="hlt">sediment</span> pulse. Comparison of observed erosion with pre-removal modeling shows that reservoir erosion exceeded model predictions by two orders of magnitude in the unconfined Clark Fork arm of the reservoir. In addition, fine reservoir <span class="hlt">sediments</span> predicted to move exclusively in suspension traveled as bedload at lower <span class="hlt">transport</span> stages. The resulting fine <span class="hlt">sediment</span> deposition in substrate interstices, on bars, and in side channels of the gravel- and cobble-bed Clark Fork River is the most</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2015/1055/index.html','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2015/1055/index.html"><span>Effects of proposed <span class="hlt">sediment</span> borrow pits on nearshore wave climate and longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> rate along Breton Island, Louisiana</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dalyander, Patricia (Soupy); Mickey, Rangley C.; Long, Joseph W.; Flocks, James G.</p> <p>2015-05-02</p> <p>As part of a plan to preserve bird habitat on Breton Island, the southernmost extent of the Chandeleur Islands and part of the Breton National Wildlife Refuge in Louisiana, the U.S. Fish and Wildlife Service plans to increase island elevation with sand supplied from offshore resources. Proposed sand extraction sites include areas offshore where the seafloor morphology suggests suitable quantities of <span class="hlt">sediment</span> may be found. Two proposed locations east and south of the island, between 5.5–9 kilometers from the island in 3–6 meters of water, have been identified. Borrow pits are perturbations to shallow-water bathymetry and thus can affect the wave field in a variety of ways, including alterations in <span class="hlt">sediment</span> <span class="hlt">transport</span> and new erosional or accretional patterns along the beach. A scenario-based numerical modeling strategy was used to assess the effects of the proposed offshore borrow pits on the nearshore wave field. Effects were assessed over a range of wave conditions and were gaged by changes in significant wave height and wave direction inshore of the borrow sites, as well as by changes in the calculated longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> rate. The change in magnitude of the calculated <span class="hlt">sediment</span> <span class="hlt">transport</span> rate with the addition of the two borrow pits was an order of magnitude less than the calculated baseline <span class="hlt">transport</span> rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29934827','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29934827"><span>Modeling of <span class="hlt">sediment</span> <span class="hlt">transport</span> in a saltwater lake with supplemental sandy freshwater.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liang, Li; Deng, Yun; Li, Ran; Li, Jia</p> <p>2018-06-22</p> <p>Considering the highly complex flow structure of saltwater lakes during freshwater supplementation, a three-dimensional numerical model was developed to simulate suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in saltwater lakes. The model was validated using measurements of the salinity and <span class="hlt">sediment</span> concentration during a pumping test at Yamdrok Lake. The simulation results were in quantitative agreement with the measured data. The observed and simulated results also indicated that the wind stress and vertical salinity gradient have a significant influence on salinity and <span class="hlt">sediment</span> <span class="hlt">transport</span> in a saltwater lake. The validated model was then used to predict and analyze the contributions of wind, the supplement flow rate and salinity stratification to the <span class="hlt">sediment</span> <span class="hlt">transport</span> process in Yamdrok Lake during continuous river water supplementation. The simulation results showed that after the sandy river water was continuously discharged into the saltwater lake, the lateral diffusion trends of the <span class="hlt">sediment</span> exhibited three stages: linear growth in the inflow direction, logarithmic growth in the wind direction, and stabilization. Furthermore, wind was the dominant factor in driving the lake flow pattern and <span class="hlt">sediment</span> <span class="hlt">transport</span>. Specifically, wind can effectively reduce the area of the <span class="hlt">sediment</span> diffusion zone by increasing the lateral <span class="hlt">sediment</span> carrying and dilution capacities. The effect of inflow on the lake current is negligible, but the extent of the <span class="hlt">sediment</span> turbidity zone mainly depends on the inflow. Reducing the inflow discharge can decrease the area of the <span class="hlt">sediment</span> turbidity zone to proportions that far exceed the proportions of inflow discharge reductions. In addition, the high-salinity lake water can support the supplemented freshwater via buoyancy forces, which weaken vertical mixing and <span class="hlt">sediment</span> settlement and increase lake currents and <span class="hlt">sediment</span> diffusion near the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28727171','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28727171"><span>Modeling chemical accumulation in <span class="hlt">sediment</span> of small waterbodies accounting for <span class="hlt">sediment</span> <span class="hlt">transport</span> and water-<span class="hlt">sediment</span> exchange processes over long periods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Patterson, David Albert; Strehmel, Alexander; Erzgräber, Beate; Hammel, Klaus</p> <p>2017-12-01</p> <p>In a recent scientific opinion of the European Food Safety Authority it is argued that the accumulation of plant protection products in <span class="hlt">sediments</span> over long time periods may be an environmentally significant process. Therefore, the European Food Safety Authority proposed a calculation to account for plant protection product accumulation. This calculation, however, considers plant protection product degradation within <span class="hlt">sediment</span> as the only dissipation route, and does not account for <span class="hlt">sediment</span> dynamics or back-diffusion into the water column. The hydraulic model Hydrologic Engineering Center-River Analysis System (HEC-RAS; US Army Corps of Engineers) was parameterized to assess <span class="hlt">sediment</span> <span class="hlt">transport</span> and deposition dynamics within the FOrum for Co-ordination of pesticide fate models and their USe (FOCUS) scenarios in simulations spanning 20 yr. The results show that only 10 to 50% of incoming <span class="hlt">sediment</span> would be deposited. The remaining portion of <span class="hlt">sediment</span> particles is <span class="hlt">transported</span> across the downstream boundary. For a generic plant protection product substance this resulted in deposition of only 20 to 50% of incoming plant protection product substance. In a separate analysis, the FOCUS TOXSWA model was utilized to examine the relative importance of degradation versus back-diffusion as loss processes from the <span class="hlt">sediment</span> compartment for a diverse range of generic plant protection products. In simulations spanning 20 yr, it was shown that back-diffusion was generally the dominant dissipation process. The results of the present study show that <span class="hlt">sediment</span> dynamics and back-diffusion should be considered when calculating long-term plant protection product accumulation in <span class="hlt">sediment</span>. Neglecting these may lead to a systematic overestimation of accumulation. Environ Toxicol Chem 2017;36:3223-3231. © 2017 SETAC. © 2017 SETAC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26311584','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26311584"><span>Modeling suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> and assessing the impacts of climate change in a karstic Mediterranean watershed.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nerantzaki, S D; Giannakis, G V; Efstathiou, D; Nikolaidis, N P; Sibetheros, I Α; Karatzas, G P; Zacharias, I</p> <p>2015-12-15</p> <p>Mediterranean semi-arid watersheds are characterized by a climate type with long periods of drought and infrequent but high-intensity rainfalls. These factors lead to the formation of temporary flow tributaries which present flashy hydrographs with response times ranging from minutes to hours and high erosion rates with significant <span class="hlt">sediment</span> <span class="hlt">transport</span>. Modeling of suspended <span class="hlt">sediment</span> concentration in such watersheds is of utmost importance due to flash flood phenomena, during which, large quantities of <span class="hlt">sediments</span> and pollutants are carried downstream. The aim of this study is to develop a modeling framework for suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in a karstic watershed and assess the impact of climate change on flow, soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> in a hydrologically complex and intensively managed Mediterranean watershed. The Soil and Water Assessment Tool (SWAT) model was coupled with a karstic flow and suspended <span class="hlt">sediment</span> model in order to simulate the hydrology and <span class="hlt">sediment</span> yield of the karstic springs and the whole watershed. Both daily flow data (2005-2014) and monthly <span class="hlt">sediment</span> concentration data (2011-2014) were used for model calibration. The results showed good agreement between observed and modeled values for both flow and <span class="hlt">sediment</span> concentration. Flash flood events account for 63-70% of the annual <span class="hlt">sediment</span> export depending on a wet or dry year. Simulation results for a set of IPCC "A1B" climate change scenarios suggested that major decreases in surface flow (69.6%) and in the flow of the springs (76.5%) take place between the 2010-2049 and 2050-2090 time periods. An assessment of the future ecological flows revealed that the frequency of minimum flow events increases over the years. The trend of surface <span class="hlt">sediment</span> export during these periods is also decreasing (54.5%) but the difference is not statistically significant due to the variability of the <span class="hlt">sediment</span>. On the other hand, <span class="hlt">sediment</span> originating from the springs is not affected significantly by climate change</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ks.water.usgs.gov/mill-creek-sediment','USGSPUBS'); return false;" href="http://ks.water.usgs.gov/mill-creek-sediment"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> from Urban, Urbanizing, and Rural Areas in Johnson County, Kansas, 2006-08</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lee, Casey J.</p> <p>2013-01-01</p> <p>1. Studies have commonly illustrated that erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> from construction sites is extensive, typically 10-100X that of background levels. 2. However, to our knowledge, the affects of construction and urbanization have rarely been assessed (1) since erosion and <span class="hlt">sediment</span> controls have been required at construction sites, and (2) at watershed (5-65 mi2) scales. This is primarily because of difficulty characterizing <span class="hlt">sediment</span> loads in small basins. Studies (such as that illustrated from Timble, 1999) illustrated how large changes in surface erosion may not result in substantive changes in downstream <span class="hlt">sediment</span> loads (b/c of <span class="hlt">sediment</span> deposition on land-surfaces, floodplains, and in stream channels). 3. Improved technology (in-situ turbidity) sensors provide a good application b/c they provide an independent surrogate of <span class="hlt">sediment</span> concentration that is more accurate at estimating <span class="hlt">sediment</span> concentrations and loads that instantaneous streamflow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP53C0983L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP53C0983L"><span>Modifying Bagnold's <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Equation for Use in Watershed-Scale Channel Incision Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lammers, R. W.; Bledsoe, B. P.</p> <p>2016-12-01</p> <p>Destabilized stream channels may evolve through a sequence of stages, initiated by bed incision and followed by bank erosion and widening. Channel incision can be modeled using Exner-type mass balance equations, but model accuracy is limited by the accuracy and applicability of the selected <span class="hlt">sediment</span> <span class="hlt">transport</span> equation. Additionally, many <span class="hlt">sediment</span> <span class="hlt">transport</span> relationships require significant data inputs, limiting their usefulness in data-poor environments. Bagnold's empirical relationship for bedload <span class="hlt">transport</span> is attractive because it is based on stream power, a relatively straightforward parameter to estimate using remote sensing data. However, the equation is also dependent on flow depth, which is more difficult to measure or estimate for entire drainage networks. We recast Bagnold's original <span class="hlt">sediment</span> <span class="hlt">transport</span> equation using specific discharge in place of flow depth. Using a large dataset of <span class="hlt">sediment</span> <span class="hlt">transport</span> rates from the literature, we show that this approach yields similar predictive accuracy as other stream power based relationships. We also explore the applicability of various critical stream power equations, including Bagnold's original, and support previous conclusions that these critical values can be predicted well based solely on <span class="hlt">sediment</span> grain size. In addition, we propagate error in these <span class="hlt">sediment</span> <span class="hlt">transport</span> equations through channel incision modeling to compare the errors associated with our equation to alternative formulations. This new version of Bagnold's bedload <span class="hlt">transport</span> equation has utility for channel incision modeling at larger spatial scales using widely available and remote sensing data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/8362','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/8362"><span>A <span class="hlt">sediment</span> <span class="hlt">transport</span> model for incision of gullies on steep topography</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Erkan Istanbulluoglu; David G. Tarboton; Robert T. Pack; Charles H. Luce</p> <p>2003-01-01</p> <p>We have conducted surveys of gullies that developed in a small, steep watershed in the Idaho Batholith after a severe wildfire followed by intense precipitation. We measured gully length and cross sections to estimate the volumes of <span class="hlt">sediment</span> loss due to gully formation. These volume estimates are assumed to provide an estimate of <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity at each...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=60635&Lab=NERL&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=60635&Lab=NERL&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>PREDICTION OF CONTAMINATED <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> IN THE MAURICE RIVER-UNION LAKE, NEW JERSEY, USA</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This paper describes a <span class="hlt">sediment</span> and contaminant <span class="hlt">transport</span> model and its application to the Maurice River-Union Lake system in southern New Jersey, USA for the purpose of characterizing and forecasting <span class="hlt">sediment</span> and arsenic distributions before and after proposed dredging activitie...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=65874&Lab=NERL&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=65874&Lab=NERL&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>PREDICTION OF CONTAMINATED <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> IN THE MAURICE RIVER-UNION LAKE, NEW JERSEY, USA</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>A <span class="hlt">sediment</span> and contaminant <span class="hlt">transport</span> model and its application to the Maurice River-Union Lake system in southern New Jersey, USA is described. The application is meant to characterize and forecast <span class="hlt">sediment</span> and arsenic (As) distributions before and after proposed dredging activit...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA581955','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA581955"><span>Quantifying Enhanced Microbial Dehalogenation Impacting the Fate and <span class="hlt">Transport</span> of Organohalide Mixtures in Contaminated <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-02-01</p> <p>supplying Anacostia River <span class="hlt">sediment</span>, Dr. Matti Verta, Finnish Environment Institute, for providing Kymijoki River <span class="hlt">sediment</span>, and the Meadowlands...dehalogenating activity; 2) Characterize the effect of sedimentary conditions on the ( bio )transformation rates of organohalide mixtures and their...the fate and <span class="hlt">transport</span> of organohalide contaminants, co-amendments and ( bio )transformation products under various bioremediation scenarios. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/32602','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/32602"><span>The role of geology in <span class="hlt">sediment</span> supply and bedload <span class="hlt">transport</span> patterns in coarse-grained streams</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Sandra E. Ryan</p> <p>2007-01-01</p> <p>This paper compares gross differences in rates of bedload <span class="hlt">sediment</span> moved at bankfull discharges in 19 channels on national forests in the Middle and Southern Rocky Mountains. Each stream has its own "bedload signal," in that the rate and size of materials <span class="hlt">transported</span> at bankfull discharge largely reflect the nature of flow and <span class="hlt">sediment</span> particular to that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1983/4060/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1983/4060/report.pdf"><span>A preliminary appraisal of <span class="hlt">sediment</span> sources and <span class="hlt">transport</span> in Kings Bay and vicinity, Georgia and Florida</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McConnell, J.B.; Radtke, D.B.; Hale, T.W.; Buell, G.R.</p> <p>1983-01-01</p> <p>Water-quality, bottom-material, suspended-<span class="hlt">sediment</span>, and current-velocity data were collected during November 1981 in Kings Bay and vicinity to provide information on the sources and <span class="hlt">transport</span> of estuarine <span class="hlt">sediments</span>. Kings Bay and Cumberland Sound , the site of the Poseidon Submarine Base in southeast Georgia, are experiencing high rates of <span class="hlt">sediment</span> deposition and accumulation, which are causing serious navigational and operational problems. Velocity, bathymetry, turbidity, and bottom-material data suggest that the area in the vicinity of lower Kings Bay is accumulating deposits of suspended <span class="hlt">sediment</span> <span class="hlt">transported</span> from Cumberland Sound on the floodtide and from upper Kings Bay and the tidal marsh drained by Marianna Creek on the ebbtide. Suspended-<span class="hlt">sediment</span> discharges computed for consecutive 13-hour ebbtides and floodtides showed that a net quantity of suspended <span class="hlt">sediment</span> was <span class="hlt">transported</span> seaward from upper Kings Bay and Marianna Creek. A net landward <span class="hlt">transport</span> of suspended <span class="hlt">sediment</span> computed at the St. Marys Entrance indicated areas seaward of St. Marys Entrance may be supplying <span class="hlt">sediment</span> to the shoaling areas of the estuary, including lower Kings Bay. (USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://mo.water.usgs.gov/Reports/WRIR01-4269/index.htm','USGSPUBS'); return false;" href="http://mo.water.usgs.gov/Reports/WRIR01-4269/index.htm"><span>Numerical simulation of streamflow distribution, <span class="hlt">sediment</span> <span class="hlt">transport</span>, and <span class="hlt">sediment</span> deposition along Long Beach Creek in Northeast Missouri</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Heimann, David C.</p> <p>2001-01-01</p> <p>This report presents the results of a study conducted by the U.S. Geological Survey in cooperation with the Missouri Department of Conservation to describe the hydrology, <span class="hlt">sediment</span> <span class="hlt">transport</span>, and <span class="hlt">sediment</span> deposition along a selected reach of Long Branch Creek in Macon County, Missouri. The study was designed to investigate spatial and temporal characteristics of <span class="hlt">sediment</span> deposition in a remnant forested riparian area and compare these factors by magnitude of discharge events both within and outside the measured range of flood magnitudes. The two-dimensional finite-element numerical models RMA2-WES and SED2D-WES were used in conjunction with measured data to simulate streamflow and <span class="hlt">sediment</span> <span class="hlt">transport</span>/deposition characteristics during 2-, 5-, 10-, and 25-year recurrence interval floods. Spatial analysis of simulated <span class="hlt">sediment</span> deposition results indicated that mean deposition in oxbows and secondary channels exceeded that of the remaining floodplain areas during the 2-, 5-, 10-, and 25-year recurrence interval floods. The simulatedmass deposition per area for oxbows and secondary channels was 1.1 to 1.4 centimeters per square meter compared with 0.1 to 0.60 centimeters per square meter for the remaining floodplain. The temporal variability of total incremental floodplain deposition during a flood was found to be strongly tied to <span class="hlt">sediment</span> inflowconcentrations. Most floodplain deposition, therefore, occurred at the beginning of the streamflow events and corresponded to peaks in <span class="hlt">sediment</span> discharge. Simulated total <span class="hlt">sediment</span> deposition in oxbows and secondary channels increased in the 2-year through 10-year floods and decreased in the 25- year flood while remaining floodplain deposition was highest for the 25-year flood. Despite increases in <span class="hlt">sediment</span> inflows from the 2-year through 25-year floods, the retention ratio of <span class="hlt">sediments</span> (the ratio of floodplain deposition to inflow load) was greatest for the 5-year flood and least for the 25-year flood. The decrease in retention</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/3176','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/3176"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Investigations on the National Forests of Alabama</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Johnny M. Grace</p> <p>2002-01-01</p> <p>In recent years, increased concern and societal pressure have focused on environmental impacts of forest roads on soil erosion and water quality. Forest roads have been identified as the major contributor to <span class="hlt">sediment</span> production from forested lands accounting for as much as 90 percent of all <span class="hlt">sediment</span> produced from forest lands. This paper reports on two research studies...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740018798','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740018798"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and erosion in the Fourchon area of Lafourche parish. [south Louisiana</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whitehurst, C. A.; Self, R. P.</p> <p>1974-01-01</p> <p>NASA aerial photography in the form of color infrared and color positive transparencies is used as an aid in evaluating the rate and effect of erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> in Bay Champagne Louisiana.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28798390','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28798390"><span>Windblown <span class="hlt">sediment</span> <span class="hlt">transport</span> and loss in a desert-oasis ecotone in the Tarim Basin.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pi, Huawei; Sharratt, Brenton; Lei, Jiaqiang</p> <p>2017-08-10</p> <p>The Tarim Basin is regarded as one of the most highly erodible areas in China. Desert comprises 64% of the land use in the Basin, but the desert-oasis ecotone plays a prominent role in maintaining oasis ecological security and stability. Yet, little is known concerning the magnitude of windblown <span class="hlt">sediment</span> <span class="hlt">transport</span> in a desert-oasis ecotone. Therefore, aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> and loss was assessed from a desert-oasis experimental site located near Alaer City in the northwestern Tarim Basin. <span class="hlt">Sediment</span> <span class="hlt">transport</span> and factors governing <span class="hlt">transport</span> were measured during three high wind events in 2012 and four events in 2013. <span class="hlt">Sediment</span> <span class="hlt">transport</span> was measured to a height of 10 m using passive aeolian airborne <span class="hlt">sediment</span> samplers. The mass flux profile over the eroding surface was well represented by the power-law (R 2  > 0.77). <span class="hlt">Sediment</span> loss from the site ranged from 118 g m -2 for the 20-24Apr 2012 wind event to 2925 g m -2 for the 31Mar-11Apr 2012 event. Suspension accounted for 67.4 to 84.8% of <span class="hlt">sediment</span> loss across all high wind events. Our results indicate the severity of wind erosion in a desert-oasis ecotone and thus encourage adoption of management practices that will enhance oasis ecological security.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2017/5081/sir20175081.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2017/5081/sir20175081.pdf"><span>Characterization of <span class="hlt">sediment</span> <span class="hlt">transport</span> upstream and downstream from Lake Emory on the Little Tennessee River near Franklin, North Carolina, 2014–15</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Huffman, Brad A.; Hazell, William F.; Oblinger, Carolyn J.</p> <p>2017-09-06</p> <p>Federal, State, and local agencies and organizations have expressed concerns regarding the detrimental effects of excessive <span class="hlt">sediment</span> <span class="hlt">transport</span> on aquatic resources and endangered species populations in the upper Little Tennessee River and some of its tributaries. In addition, the storage volume of Lake Emory, which is necessary for flood control and power generation, has been depleted by <span class="hlt">sediment</span> deposition. To help address these concerns, a 2-year study was conducted in the upper Little Tennessee River Basin to characterize the ambient suspended-<span class="hlt">sediment</span> concentrations and suspended-<span class="hlt">sediment</span> loads upstream and downstream from Lake Emory in Franklin, North Carolina. The study was conducted by the U.S. Geological Survey in cooperation with Duke Energy. Suspended-<span class="hlt">sediment</span> samples were collected periodically, and time series of stage and turbidity data were measured from December 2013 to January 2016 upstream and downstream from Lake Emory. The stage data were used to compute time-series streamflow. Suspended-<span class="hlt">sediment</span> samples, along with time-series streamflow and turbidity data, were used to develop regression models that were used to estimate time-series suspended-<span class="hlt">sediment</span> concentrations for the 2014 and 2015 calendar years. These concentrations, along with streamflow data, were used to compute suspended-<span class="hlt">sediment</span> loads. Selected suspended-<span class="hlt">sediment</span> samples were collected for analysis of particle-size distribution, with emphasis on high-flow events. <span class="hlt">Bed-load</span> samples were also collected upstream from Lake Emory.The estimated annual suspended-<span class="hlt">sediment</span> loads (yields) for the upstream site for the 2014 and 2015 calendar years were 27,000 short tons (92 short tons per square mile) and 63,300 short tons (215 short tons per square mile), respectively. The annual suspended-<span class="hlt">sediment</span> loads (yields) for the downstream site for 2014 and 2015 were 24,200 short tons (75 short tons per square mile) and 94,300 short tons (292 short tons per square mile), respectively. Overall, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H54E..06D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H54E..06D"><span>Methane Bubbles <span class="hlt">Transport</span> Particles From Contaminated <span class="hlt">Sediment</span> to a Lake Surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delwiche, K.; Hemond, H.</p> <p>2017-12-01</p> <p>Methane bubbling from aquatic <span class="hlt">sediments</span> has long been known to <span class="hlt">transport</span> carbon to the atmosphere, but new evidence presented here suggests that methane bubbles also <span class="hlt">transport</span> particulate matter to a lake surface. This <span class="hlt">transport</span> pathway is of particular importance in lakes with contaminated <span class="hlt">sediments</span>, as bubble <span class="hlt">transport</span> could increase human exposure to toxic metals. The Upper Mystic Lake in Arlington, MA has a documented history of methane bubbling and <span class="hlt">sediment</span> contamination by arsenic and other heavy metals, and we have conducted laboratory and field studies demonstrating that methane bubbles are capable of <span class="hlt">transporting</span> <span class="hlt">sediment</span> particles over depths as great as 15 m in Upper Mystic Lake. Methane bubble traps were used in-situ to capture particles adhered to bubble interfaces, and to relate particle mass <span class="hlt">transport</span> to bubble flux. Laboratory studies were conducted in a custom-made 15 m tall water column to quantify the relationship between water column height and the mass of particulate <span class="hlt">transport</span>. We then couple this particle <span class="hlt">transport</span> data with historical estimates of ebullition from Upper Mystic Lake to quantify the significance of bubble-mediated particle <span class="hlt">transport</span> to heavy metal cycling within the lake. Results suggest that methane bubbles can represent a significant pathway for contaminated <span class="hlt">sediment</span> to reach surface waters even in relatively deep water bodies. Given the frequent co-occurrence of contaminated <span class="hlt">sediments</span> and high bubble flux rates, and the potential for human exposure to heavy metals, it will be critical to study the significance of this <span class="hlt">transport</span> pathway for a range of <span class="hlt">sediment</span> and contaminant types.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/26841','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/26841"><span><span class="hlt">Transport</span> of bedload <span class="hlt">sediment</span> and channel morphology of a southeast Alaska stream.</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Margaret A. Estep; Robert L. Beschta</p> <p>1985-01-01</p> <p>During 1980-81, <span class="hlt">transport</span> of bedload <span class="hlt">sediment</span> and channel morphology were determined at Trap Bay Creek, a third-order stream that drains a 13.5-square kilometer watershed on Chichagof island in southeast Alaska. Bedload <span class="hlt">sediment</span> was sampled for 10 storms: peak flows ranged from 0.6 to 19.0 cubic meters per second, and <span class="hlt">transport</span> rates ranged from 4 to 4400 kilograms per...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H21F0789Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H21F0789Q"><span>Temporal Variability of Suspended <span class="hlt">Sediment</span> Load, Dissolved Load, and Bedload for Two Small Oak Forested Catchments with Contrasting Disturbance Levels in the Lesser Himalaya of North-West India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qazi, N. U. Q.; Rai, S. P.; Bruijnzeel, L. A.</p> <p>2014-12-01</p> <p><span class="hlt">Sediment</span> transfer from mountainous areas to lowland areas is one of the most important geomorphological processes globally with the bulk of the <span class="hlt">sediment</span> yield from such areas typically deriving from mass wastage processes. This study presents monthly, seasonal and annual variations in <span class="hlt">sediment</span> <span class="hlt">transport</span> (both suspended load and <span class="hlt">bed</span> <span class="hlt">load</span>) as well as dissolved loads over three consecutive water years (2008-2011) for two small forested watersheds with contrasting levels of forest disturbance in the Lesser Himalaya of Northwest India. Seasonal and annual suspended <span class="hlt">sediment</span> yields were strongly influenced by amounts of rainfall and stream flow and showed a 23-fold range between wet and dry years. Of the annual load, some 92% was produced on average during the monsoon season (June-September). <span class="hlt">Sediment</span> production by the disturbed forest catchment was 2.6-fold (suspended <span class="hlt">sediment</span>) to 5.9-fold (<span class="hlt">bed</span> <span class="hlt">load</span>) higher than that for the well-stocked forest catchment. By contrast, dissolved loads varied much less between years, seasons (although minimal during the dry summer season), and degree of forest disturbance. Total mechanical denudation rates were 1.2 times and 4.7 times larger than chemical denudation rates for the little disturbed and the heavily disturbed forest catchment, respectively whereas overall denudation rates were estimated at 0.59 and 1.05 mm per 1000 years, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13B1616O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13B1616O"><span>Deciphering Equatorial Pacific Deep Sea <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Regimes by Core-Log-Seismic Integration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortiz, E.; Tominaga, M.; Marcantonio, F.</p> <p>2017-12-01</p> <p>Investigating deep-sea <span class="hlt">sediment</span> <span class="hlt">transportation</span> and deposition regimes is a key to accurately understand implications from geological information recorded by pelagic <span class="hlt">sediments</span>, e.g. climate signals. However, except for physical oceanographic particle trap experiments, geochemical analyses of in situsediments, and theoretical modeling of the relation between the bottom currents and <span class="hlt">sediment</span> particle flux, it has remained a challenging task to document the movement of deep sea <span class="hlt">sediments</span>, that takes place over time. We utilized high-resolution, multichannel reflection seismic data from the eastern equatorial Pacific region with drilling and logging results from two Integrated Ocean Drilling Program (IODP) sites, the Pacific Equatorial Age Transect (PEAT) 7 (Site U1337) and 8 (Site U1338), to characterize <span class="hlt">sediment</span> <span class="hlt">transportation</span> regimes on 18-24 Ma oceanic crust. Site U1337, constructed by a series of distinct abyssal hills and abyssal basins; Site U1338, located 570 km SE from Site U1337 site and constructed by a series of ridges, seamounts, and abyssal hills. These sites are of particular interest due to their proximity to the equatorial productivity zone, areas with high <span class="hlt">sedimentation</span> rates and preservation of carbonate-bearing <span class="hlt">sediment</span> that provide invaluable insights on equatorial Pacific ecosystems and carbon cycle. We integrate downhole geophysical logging data as well as geochemistry and physical properties measurements on recovered cores from IODP Sites U1337 and U1338 to comprehensively examine the mobility of deep-sea <span class="hlt">sediments</span> and <span class="hlt">sediment</span> diagenesis over times in a quasi-3D manner. We also examine 1100 km of high resolution underway seismic surveys from site survey lines in between PEAT 7 and 8 in order to investigate changes in <span class="hlt">sediment</span> <span class="hlt">transportation</span> between both sites. Integrating detailed seismic interpretations, high resolution core data, and 230Th flux measurements we aim to create a detailed chronological <span class="hlt">sedimentation</span> and <span class="hlt">sediment</span> diagenesis history</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004HyPr...18..667G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004HyPr...18..667G"><span>Hydrogeomorphic linkages of <span class="hlt">sediment</span> <span class="hlt">transport</span> in headwater streams, Maybeso Experimental Forest, southeast Alaska</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gomi, Takashi; Sidle, Roy C.; Swanston, Douglas N.</p> <p>2004-03-01</p> <p>Hydrogemorphic linkages related to <span class="hlt">sediment</span> <span class="hlt">transport</span> in headwater streams following basin wide clear-cut logging on Prince of Wales Island, southeast Alaska, were investigated. Landslides and debris flows <span class="hlt">transported</span> <span class="hlt">sediment</span> and woody debris in headwater tributaries in 1961, 1979, and 1993. Widespread landsliding in 1961 and 1993 was triggered by rainstorms with recurrence intervals (24 h precipitation) of 7.0 years and 4.2 years respectively. Occurrence, distribution, and downstream effects of these mass movements were controlled by landform characteristics such as channel gradient and valley configuration. Landslides and channelized debris flows created exposed bedrock reaches, log jams, fans, and abandoned channels. The terminus of the deposits did not enter main channels because debris flows spread and thinned on the unconfined bottom of the U-shaped glaciated valley. Chronic <span class="hlt">sediment</span> input to channels included surface erosion of exposed till (rain splash, sheet erosion, and freeze-thaw action) and bank failures. Bedload <span class="hlt">sediment</span> <span class="hlt">transport</span> in a channel impacted by 1993 landslides and debris flows was two to ten times greater and relatively finer compared with bedload <span class="hlt">transport</span> in a young alder riparian channel that had last experienced a landslide and debris flow in 1961. <span class="hlt">Sediment</span> <span class="hlt">transport</span> and storage were influenced by regeneration of riparian vegetation, storage behind recruited woody debris, development of a streambed armour layer, and the decoupling of hillslopes and channels. Both spatial and temporal variations of <span class="hlt">sediment</span> movement and riparian condition are important factors in understanding material <span class="hlt">transport</span> within headwaters and through channel networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhDT........42T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhDT........42T"><span>Investigations of grain size dependent <span class="hlt">sediment</span> <span class="hlt">transport</span> phenomena on multiple scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thaxton, Christopher S.</p> <p></p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> processes in coastal and fluvial environments resulting from disturbances such as urbanization, mining, agriculture, military operations, and climatic change have significant impact on local, regional, and global environments. Primarily, these impacts include the erosion and deposition of <span class="hlt">sediment</span>, channel network modification, reduction in downstream water quality, and the delivery of chemical contaminants. The scale and spatial distribution of these effects are largely attributable to the size distribution of the <span class="hlt">sediment</span> grains that become eligible for <span class="hlt">transport</span>. An improved understanding of advective and diffusive grain-size dependent <span class="hlt">sediment</span> <span class="hlt">transport</span> phenomena will lead to the development of more accurate predictive models and more effective control measures. To this end, three studies were performed that investigated grain-size dependent <span class="hlt">sediment</span> <span class="hlt">transport</span> on three different scales. Discrete particle computer simulations of sheet flow bedload <span class="hlt">transport</span> on the scale of 0.1--100 millimeters were performed on a heterogeneous population of grains of various grain sizes. The relative <span class="hlt">transport</span> rates and diffusivities of grains under both oscillatory and uniform, steady flow conditions were quantified. These findings suggest that boundary layer formalisms should describe surface roughness through a representative grain size that is functionally dependent on the applied flow parameters. On the scale of 1--10m, experiments were performed to quantify the hydrodynamics and <span class="hlt">sediment</span> capture efficiency of various baffles installed in a <span class="hlt">sediment</span> retention pond, a commonly used <span class="hlt">sedimentation</span> control measure in watershed applications. Analysis indicates that an optimum <span class="hlt">sediment</span> capture effectiveness may be achieved based on baffle permeability, pond geometry and flow rate. Finally, on the scale of 10--1,000m, a distributed, bivariate watershed terain evolution module was developed within GRASS GIS. Simulation results for variable grain sizes and for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70013812','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70013812"><span>Suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> under estuarine tidal channel conditions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sternberg, R.W.; Kranck, K.; Cacchione, D.A.; Drake, D.E.</p> <p>1988-01-01</p> <p>A modified version of the GEOPROBE tripod has been used to monitor flow conditions and suspended <span class="hlt">sediment</span> distribution in the bottom boundary layer of a tidal channel within San Francisco Bay, California. Measurements were made every 15 minutes over three successive tidal cycles. They included mean velocity profiles from four electromagnetic current meters within 1 m of the seabed; mean suspended <span class="hlt">sediment</span> concentration profiles from seven miniature nephelometers operated within 1 m of the seabed; near-bottom pressure fluctuations; vertical temperature gradient; and bottom photographs. Additionally, suspended <span class="hlt">sediment</span> was sampled from four levels within 1 m of the seabed three times during each successive flood and ebb cycle. While the instrument was deployed, STD-nephelometer measurements were made throughout the water column, water samples were collected each 1-2 hours, and bottom <span class="hlt">sediment</span> was sampled at the deployment site. From these measurements, estimates were made of particle settling velocity (ws) from size distributions of the suspended <span class="hlt">sediment</span>, friction velocity (U*) from the velocity profiles, and reference concentration (Ca) was measured at z = 20 cm. These parameters were used in the suspended <span class="hlt">sediment</span> distribution equations to evaluate their ability to predict the observed suspended <span class="hlt">sediment</span> profiles. Three suspended <span class="hlt">sediment</span> particle conditions were evaluated: (1) individual particle size in the 4-11 ?? (62.5-0.5 ??m) range with the reference concentration Ca at z = 20 cm (C??), (2) individual particle size in the 4-6 ?? size range, flocs representing the 7-11 ?? size range with the reference concentration Ca at z = 20 cm (Cf), and (3) individual particle size in the 4-6 ?? size range, flocs representing the 7-11 ?? size range with the reference concentration predicted as a function of the bed <span class="hlt">sediment</span> size distribution and the square of the excess shear stress. In addition, computations of particle flux were made in order to show vertical variations</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/37454','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/37454"><span><span class="hlt">Sediment</span> production and downslope <span class="hlt">sediment</span> <span class="hlt">transport</span> from forest roads in granitic watersheds</span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Gary L. Ketcheson; Walter F. Megahan</p> <p>1996-01-01</p> <p>A mapping technique was used to measure the annual downslope deposition of granitic <span class="hlt">sediments</span> eroded from forest roads on three headwater watersheds in the mountains of central Idaho. Frequency distributions were developed to determine <span class="hlt">sediment</span> travel distance, and a dimensionless relationship was developed to describe the relation between the percentage of total...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFMOS21D..08B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFMOS21D..08B"><span>Field Observations of Hydrodynamics, <span class="hlt">Sediment</span> <span class="hlt">Transport</span>, and Water and <span class="hlt">Sediment</span> Quality in the Hudson-Raritan Estuary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bruno, M. S.; Glenn, S.; Chant, R.; Rankin, K.; Korfiatis, G.; Dimou, N.; Creed, E.; Fullerton, B.; Pence, A.; Burke, P.; Haldeman, C.; Hires, R.; Hunter, E.</p> <p>2002-12-01</p> <p>The New York-New Jersey Harbor estuary system is of enormous ecological and economic importance to the region. The presence of toxic chemicals in the water and <span class="hlt">sediments</span> results in reduced water quality, fisheries restrictions/advisories, and general adverse impacts to the estuarine ecosystem. The Port of New York and New Jersey is central to the economy of the region. However, in recent years, problems associated with the management of contaminated dredged material, including high costs and the lack of suitable disposal/use alternatives, have threatened to impact the volume of shipping in the Harbor. Sources of contaminants include atmospheric deposition, municipal and industrial wastewater treatment facilities, combined sewer and stormwater outfalls, and rainfall-induced runoff (non-point sources). In addition, Harbor <span class="hlt">sediments</span> can act as a continuing source as they are re-suspended and moved throughout the system by both natural and man-made means. As part of the New Jersey Toxics Reduction Workplan, Stevens Institute of Technology and Rutgers University are conducting hydrodynamic, <span class="hlt">sediment</span> <span class="hlt">transport</span>, and water and suspended <span class="hlt">sediment</span> quality measurements in Newark Bay, the Arthur Kill and the Kill van Kull. The goals of the project include: (1) collection of high resolution (event-driven and long-term) hydrodynamic, <span class="hlt">sediment</span> <span class="hlt">transport</span> and water and suspended <span class="hlt">sediment</span> quality measurements for use in the assessment of the dominant physics of the system and in the development of a combined hydrodynamic-<span class="hlt">sediment</span> <span class="hlt">transport-water/sediment</span> quality model for the region. (2) identification of those tributaries to NY-NJ Harbor that are significant sources of the chemicals of concern, and evaluation of the importance of non-point sources and existing contaminated bottom <span class="hlt">sediments</span> as sources of the chemicals of concern. (3) identification of point discharges that represent significant sources of the chemicals of concern. Observations were obtained over a two-year period</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70040449','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70040449"><span>Bathymetric controls on <span class="hlt">sediment</span> <span class="hlt">transport</span> in the Hudson River estuary: Lateral asymmetry and frontal trapping</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ralston, David K.; Geyer, W. Rockwell; Warner, John C.</p> <p>2012-01-01</p> <p>Analyses of field observations and numerical model results have identified that <span class="hlt">sediment</span> <span class="hlt">transport</span> in the Hudson River estuary is laterally segregated between channel and shoals, features frontal trapping at multiple locations along the estuary, and varies significantly over the spring-neap tidal cycle. Lateral gradients in depth, and therefore baroclinic pressure gradient and stratification, control the lateral distribution of <span class="hlt">sediment</span> <span class="hlt">transport</span>. Within the saline estuary, <span class="hlt">sediment</span> fluxes are strongly landward in the channel and seaward on the shoals. At multiple locations, bottom salinity fronts form at bathymetric transitions in width or depth. <span class="hlt">Sediment</span> convergences near the fronts create local maxima in suspended-<span class="hlt">sediment</span> concentration and deposition, providing a general mechanism for creation of secondary estuarine turbidity maxima at bathymetric transitions. The lateral bathymetry also affects the spring-neap cycle of <span class="hlt">sediment</span> suspension and deposition. In regions with broad, shallow shoals, the shoals are erosional and the channel is depositional during neap tides, with the opposite pattern during spring tides. Narrower, deeper shoals are depositional during neaps and erosional during springs. In each case, the lateral transfer is from regions of higher to lower bed stress, and depends on the elevation of the pycnocline relative to the bed. Collectively, the results indicate that lateral and along-channel gradients in bathymetry and thus stratification, bed stress, and <span class="hlt">sediment</span> flux lead to an unsteady, heterogeneous distribution of <span class="hlt">sediment</span> <span class="hlt">transport</span> and trapping along the estuary rather than trapping solely at a turbidity maximum at the limit of the salinity intrusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP51F..07W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP51F..07W"><span>The Dynamics of Coarse <span class="hlt">Sediment</span> Transfer in an Upland Bedrock River</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Warburton, J.; Hardy, R. J.; Ferguson, R. I.; Cray, A.</p> <p>2010-12-01</p> <p>Bedrock channels in UK environments have received relatively little attention despite their importance within upland river systems and their influence on controlling the conveyance of <span class="hlt">sediment</span> downstream. This poster describes the transfer of coarse <span class="hlt">sediment</span> through Trout Beck, an upland bedrock reach in the North Pennines, UK. The <span class="hlt">transport</span> of coarse <span class="hlt">sediment</span> has been quantified through field monitoring of <span class="hlt">sediment</span> characteristics, repeat magnetic tracer surveys and in-situ <span class="hlt">bed</span> <span class="hlt">load</span> impact sensors. This was carried out in conjunction with surveys of channel morphology (using terrestrial laser scanning and repeat dGPS measurements) and continuous flow monitoring. The interaction between mobile <span class="hlt">sediment</span> and channel morphology is partly conditioned by the extent of alluvial <span class="hlt">sediment</span> cover. <span class="hlt">Sediment</span> storage is patchy with partially alluvial and alluvial sections of the channel, interspersed with bedrock reaches containing very little <span class="hlt">sediment</span> except in hydraulically sheltered sites. There are notable differences in <span class="hlt">sediment</span> dynamics between these different sections of the river channel which have a considerable influence on conveyance of <span class="hlt">sediment</span> through the reach. In bedrock sections the low resistance to flow and stable channel boundaries result in little <span class="hlt">sediment</span> storage and during periods when flow is competent there is downstream conveyance of the full grain-size distribution of <span class="hlt">sediment</span>. Detailed morphological survey has provided the necessary boundary conditions, along with the flow data, to apply a one-dimensional hydraulic model (HEC-RAS) of the bedrock study reach. The modelling results have quantified the hydraulic regime of the channel. Using local shear stress as a proxy for <span class="hlt">sediment</span> <span class="hlt">transport</span>, <span class="hlt">sediment</span> <span class="hlt">transport</span> potential for the dominant grain-size distribution of the reach (16-256 mm) has been assessed for different locations in the channel. There are significant differences in the critical threshold of shear stress for <span class="hlt">sediment</span> <span class="hlt">transport</span> down the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA639807','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA639807"><span><span class="hlt">Transport</span> of Gas and Solutes in Permeable Estuarine <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-09-30</p> <p>shallow sand <span class="hlt">sediments</span> colonized by photosynthetizing diatoms and cyanobacteria . Photosynthetically active radiation at the water surface raged from...explained with the reduction of the compressible gas volume. Fig. 6. Left graph: Hysteresis in small bubble</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA211045','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA211045"><span>Verification of the Hydrodynamic and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Hybrid Modeling System for Cumberland Sound and Kings Bay Navigation Channel, Georgia</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1989-07-01</p> <p>TECHNICAL REPORT HL-89-14 VERIFICATION OF THE HYDRODYNAMIC AND Si <span class="hlt">SEDIMENT</span> <span class="hlt">TRANSPORT</span> HYBRID MODELING SYSTEM FOR CUMBERLAND SOUND AND I’) KINGS BAY...Hydrodynamic and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Hybrid Modeling System for Cumberland Sound and Kings Bay Navigation Channel, Georgia 12 PERSONAL AUTHOR(S) Granat...Hydrodynamic results from RMA-2V were used in the numerical <span class="hlt">sediment</span> <span class="hlt">transport</span> code STUDH in modeling the interaction of the flow <span class="hlt">transport</span> and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70175626','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70175626"><span>Modeling flow, <span class="hlt">sediment</span> <span class="hlt">transport</span> and morphodynamics in rivers</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nelson, Jonathan M.; McDonald, Richard R.; Shimizu, Yasuyuki; Kimura, Ichiro; Nabi, Mohamed; Asahi, Kazutake</p> <p>2016-01-01</p> <p>Predicting the response of natural or man-made channels to imposed supplies of water and <span class="hlt">sediment</span> is one of the difficult practical problems commonly addressed by fluvial geomorphologists. This problem typically arises in three situations. In the first situation, geomorphologists are attempting to understand why a channel or class of channels has a certain general form; in a sense, this is the central goal of fluvial geomorphology. In the second situation, geomorphologists are trying to understand and explain how and why a specific channel will evolve or has evolved in response to altered or unusual <span class="hlt">sediment</span> and water supplies to that channel. For example, this would include explaining the short-term response of a channel to an unusually large flood or predicting the response of a channel to long-term changes in flow or <span class="hlt">sediment</span> supply due to various human activities such as damming or diversions. Finally, geomorphologists may be called upon to design or assess the design of proposed man-made channels that must carry a certain range of flows and <span class="hlt">sediment</span> loads in a stable or at least quasi-stable manner. In each of these three situations, the problem is really the same: geomorphologists must understand and predict the interaction of the flow field in the channel, the <span class="hlt">sediment</span> movement in the channel and the geometry of the channel bed and banks. In general, the flow field, the movement of <span class="hlt">sediment</span> making up the bed and the morphology of the bed are intricately linked; the flow moves the <span class="hlt">sediment</span>, the bed is altered by erosion and deposition of <span class="hlt">sediment</span> and the shape of the bed is critically important for predicting the flow. This complex linkage is precisely what makes understanding channel form and process such a difficult and interesting challenge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513602G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513602G"><span>Structural practices for controlling <span class="hlt">sediment</span> <span class="hlt">transport</span> from erosion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gabriels, Donald; Verbist, Koen; Van de Linden, Bruno</p> <p>2013-04-01</p> <p>Erosion on agricultural fields in the hilly regions of Flanders, Belgium has been recognized as an important economical and ecological problem that requires effective control measures. This has led to the implementation of on-site and off-site measures such as reduced tillage and the installation of grass buffers trips, and dams made of vegetative materials. Dams made out of coir (coconut) and wood chips were evaluated on three different levels of complexity. Under laboratory conditions, one meter long dams were submitted to two different discharges and three <span class="hlt">sediment</span> concentrations under two different slopes, to assess the <span class="hlt">sediment</span> delivery ratios under variable conditions. At the field scale, discharge and <span class="hlt">sediment</span> concentrations were monitored under natural rainfall conditions on six 3 m wide plots, of which three were equipped with coir dams, while the other three served as control plots. The same plots were also used for rainfall simulations, which allowed controlling <span class="hlt">sediment</span> delivery boundary conditions more precisely. Results show a clear advantage of these dams to reduce discharge by minimum 49% under both field and laboratory conditions. <span class="hlt">Sediment</span> delivery ratios (SDR) were very small under laboratory and field rainfall simulations (4-9% and 2% respectively), while larger SDRs were observed under natural conditions (43%), probably due to the small <span class="hlt">sediment</span> concentrations (1-5 g l-1) observed and as such a larger influence of boundary effects. Also a clear enrichment of larger sand particles (+167%) could be observed behind the dams, showing a significant selective filtering effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H43F1084D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H43F1084D"><span>Vegetation over hydrologic control of <span class="hlt">sediment</span> <span class="hlt">transport</span> over the past 100,000 yr</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dosseto, A.; Maher, K.; Turner, S. P.; Hesse, P.; Fryirs, K.</p> <p>2008-12-01</p> <p>Uranium isotopes can be used to determine the residence time of <span class="hlt">sediments</span> in a catchment, i.e. how long they are stored in weathering profiles and <span class="hlt">transported</span> through the catchment by rivers. We have measured uranium isotopes in <span class="hlt">sediments</span> from palaeo-channels of the Murrumbidgee River (Murray-Darling Basin, southeastern Australia) to quantify variations in <span class="hlt">sediment</span> residence times over the past 100,000 years. Results indicate that <span class="hlt">sediments</span> <span class="hlt">transported</span> through the Murrumbidgee catchment during the Last Glacial Maximum (LGM) resided for 10's of thousands of years in the catchment. This contrasts with modern and 100ka-old channel <span class="hlt">sediments</span> where the residence time reaches values as high as 400,000-500,000 years. Variations in <span class="hlt">sediment</span> residence time in the Murrumbidgee basin do not strictly follow changes in bankfull discharge but instead are correlated with shifts in vegetation and atmospheric CO2. In the absence of significant glacial erosion in this basin during LGM, this is at odds with what is expected from the links between climate and erosion (a decrease in CO2 and temperature is expected to induce a decrease in weathering and erosion). Vegetation may be the link between climate and <span class="hlt">sediment</span> <span class="hlt">transport</span>: sparse vegetation in the upper catchment allows significant hillslope erosion during LGM but dense woodlands in the Holocene and during the last interglacial inhibit <span class="hlt">sediment</span> delivery to the river from hillslopes and <span class="hlt">sediments</span> are derived from the re-working of old (a few 100s ka) alluvial deposits. These observations would suggest that (i) changes in hydrology cannot explain alone changes in <span class="hlt">sediment</span> <span class="hlt">transport</span> and (ii) the impact of climate change on catchment erosion is operating indirectly, via changes in vegetation type and density. These hypothesis will be tested with studies of a more detailed sedimentary record of the Late Holocene in the Murrumbidgee and sedimentary deposits in Eastern US.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017033','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017033"><span><span class="hlt">Sediments</span> in Arctic sea ice: Implications for entrainment, <span class="hlt">transport</span> and release</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nurnberg, D.; Wollenburg, I.; Dethleff, D.; Eicken, H.; Kassens, H.; Letzig, T.; Reimnitz, E.; Thiede, Jorn</p> <p>1994-01-01</p> <p>Despite the Arctic sea ice cover's recognized sensitivity to environmental change, the role of <span class="hlt">sediment</span> inclusions in lowering ice albedo and affecting ice ablation is poorly understood. Sea ice <span class="hlt">sediment</span> inclusions were studied in the central Arctic Ocean during the Arctic 91 expedition and in the Laptev Sea (East Siberian Arctic Region Expedition 1992). Results from these investigations are here combined with previous studies performed in major areas of ice ablation and the southern central Arctic Ocean. This study documents the regional distribution and composition of particle-laden ice, investigates and evaluates processes by which <span class="hlt">sediment</span> is incorporated into the ice cover, and identifies <span class="hlt">transport</span> paths and probable depositional centers for the released <span class="hlt">sediment</span>. In April 1992, sea ice in the Laptev Sea was relatively clean. The <span class="hlt">sediment</span> occasionally observed was distributed diffusely over the entire ice column, forming turbid ice. Observations indicate that frazil and anchor ice formation occurring in a large coastal polynya provide a main mechanism for <span class="hlt">sediment</span> entrainment. In the central Arctic Ocean <span class="hlt">sediments</span> are concentrated in layers within or at the surface of ice floes due to melting and refreezing processes. The surface <span class="hlt">sediment</span> accumulation in central Arctic multi-year sea ice exceeds by far the amounts observed in first-year ice from the Laptev Sea in April 1992. Sea ice <span class="hlt">sediments</span> are generally fine grained, although coarse <span class="hlt">sediments</span> and stones up to 5 cm in diameter are observed. Component analysis indicates that quartz and clay minerals are the main terrigenous <span class="hlt">sediment</span> particles. The biogenous components, namely shells of pelecypods and benthic foraminiferal tests, point to a shallow, benthic, marine source area. Apparently, <span class="hlt">sediment</span> inclusions were resuspended from shelf areas before and incorporated into the sea ice by suspension freezing. Clay mineralogy of ice-rafted <span class="hlt">sediments</span> provides information on potential source areas. A smectite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H43G1524M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H43G1524M"><span>Streamflow response to glacier melt and related fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> in a proglacial Alpine river system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morche, D.; Schuchardt, A.; Baewert, H.; Weber, M.; Faust, M.</p> <p>2016-12-01</p> <p>Glaciers in the European Alps are retreating since the end of the Little Ice Age around 1850. Where the glaciers shrink, they leave unconsolidated <span class="hlt">sediment</span> stores (moraines, till, glacifluvial deposits). These <span class="hlt">sediment</span> stores are highly vulnerable for being subsequently eroded and are thus a key variable (source) in the fluvial <span class="hlt">sediment</span> budget of proglacial areas. The fluvial system in proglacial areas is more or less continuously fed with (fine) <span class="hlt">sediment</span> by glacial melt water (glacial milk) during the ablation period and infrequently (e.g. during rainstorm events) supplied with <span class="hlt">sediment</span> by landslides, debris flows, rock fall or fluvial <span class="hlt">transport</span> from the slopes. A part of the <span class="hlt">sediment</span> input is temporary stored in intermitted sinks, such as the river bed, bars or braid plains. These storages can be reworked and then become sources for fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> mainly during floods. These <span class="hlt">sediment</span> <span class="hlt">transporting</span> processes are highly variable in both, the temporal and spatial scale. A research project has been set up in the Kaunertal valley, Austrian Alps. The presented part of this joint project is focussed on the quantification of recent fluvial <span class="hlt">sediment</span> dynamics in the proglacial Fagge River below the glacier Gepatschferner. The glacier is located in the Eastern European Alps at the south end of the Kaunertal valley covering an area of 15.7 km² (2012) and is drained by the Fagge River. During the years 2012 to 2015 the Gepatschferner has shown an accelerated glacial retreat leading to the exposure of unconsolidated <span class="hlt">sediments</span> as well as bedrock areas. The main aim of the presented part of the joint project is the investigation of the fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> rates in the proglacial Fagge River in the Kaunertal valley. <span class="hlt">Sediment</span> output of the glacial meltwater stream was measured during the ablation periods at a gauging station installed in front of the glacier outlet. Water level was recorded every 15 minutes and discharge measurements were made at different</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.sedhyd.org/2015/openconf/modules/request.php?module=oc_program&action=summary.php&id=173','USGSPUBS'); return false;" href="http://www.sedhyd.org/2015/openconf/modules/request.php?module=oc_program&action=summary.php&id=173"><span>Suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> trough a large fluvial-tidal channel network</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wright, Scott A.; Morgan-King, Tara L.</p> <p>2015-01-01</p> <p>The confluence of the Sacramento and San Joaquin Rivers, CA, forms a large network of interconnected channels, referred to as the Sacramento-San Joaquin Delta (the Delta). The Delta comprises the transition zone from the fluvial influences of the upstream rivers and tidal influences of San Francisco Bay downstream. Formerly an extensive tidal marsh, the hydrodynamics and geomorphology of Delta have been substantially modified by humans to support agriculture, navigation, and water supply. These modifications, including construction of new channels, diking and draining of tidal wetlands, dredging of navigation channels, and the operation of large pumping facilities for distribution of freshwater from the Delta to other parts of the state, have had a dramatic impact on the physical and ecological processes within the Delta. To better understand the current physical processes, and their linkages to ecological processes, the USGS maintains an extensive network of flow, <span class="hlt">sediment</span>, and water quality gages in the Delta. Flow gaging is accomplished through use of the index-velocity method, and <span class="hlt">sediment</span> monitoring uses turbidity as a surrogate for suspended-<span class="hlt">sediment</span> concentration. Herein, we present analyses of the <span class="hlt">transport</span> and dispersal of suspended <span class="hlt">sediment</span> through the complex network of channels in the Delta. The primary source of <span class="hlt">sediment</span> to the Delta is the Sacramento River, which delivers pulses of <span class="hlt">sediment</span> primarily during winter and spring runoff events. Upon reaching the Delta, the <span class="hlt">sediment</span> pulses move through the fluvial-tidal transition while also encountering numerous channel junctions as the Sacramento River branches into several distributary channels. The monitoring network allows us to track these pulses through the network and document the dominant <span class="hlt">transport</span> pathways for suspended <span class="hlt">sediment</span>. Further, the flow gaging allows for an assessment of the relative effects of advection (the fluvial signal) and dispersion (from the tides) on the <span class="hlt">sediment</span> pulses as they</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B33B0399L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B33B0399L"><span>Beach-dune dynamics: Spatio-temporal patterns of aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> under complex offshore airflow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lynch, K.; Jackson, D.; Delgado-Fernandez, I.; Cooper, J. A.; Baas, A. C.; Beyers, M.</p> <p>2010-12-01</p> <p>This study examines sand <span class="hlt">transport</span> and wind speed across a beach at Magilligan Strand, Northern Ireland, under offshore wind conditions. Traditionally the offshore component of local wind regimes has been ignored when quantifying beach-dune <span class="hlt">sediment</span> budgets, with the sheltering effect of the foredune assumed to prohibit grain entrainment on the adjoining beach. Recent investigations of secondary airflow patterns over coastal dunes have suggested this may not be the case, that the turbulent nature of the airflow in these zones enhances <span class="hlt">sediment</span> <span class="hlt">transport</span> potential. Beach <span class="hlt">sediment</span> may be delivered to the dune toe by re-circulating eddies under offshore winds in coastal areas, which may explain much of the dynamics of aeolian dunes on coasts where the dominant wind direction is offshore. The present study investigated aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> patterns under an offshore wind event. Empirical data were collected using load cell traps, for aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span>, co-located with 3-D ultrasonic anemometers. The instrument positioning on the sub-aerial beach was informed by prior analysis of the airflow patterns using computational fluid dynamics. The array covered a total beach area of 90 m alongshore by 65 m cross-shore from the dune crest. Results confirm that <span class="hlt">sediment</span> <span class="hlt">transport</span> occurred in the ‘sheltered’ area under offshore winds. Over short time and space scales the nature of the <span class="hlt">transport</span> is highly complex; however, preferential zones for sand entrainment may be identified. Alongshore spatial heterogeneity of <span class="hlt">sediment</span> <span class="hlt">transport</span> seems to show a relationship to undulations in the dune crest, while temporal and spatial variations may also be related to the position of the airflow reattachment zone. These results highlight the important feedbacks between flow characteristics and <span class="hlt">transport</span> in a complex three dimensional surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.G41A0876F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.G41A0876F"><span>Effects of <span class="hlt">sediment</span> <span class="hlt">transport</span> and deposition on crustal loading, Earth's gravitational field, and sea level</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferrier, K.; Mitrovica, J. X.; Perron, T.; Milne, G. A.; Wickert, A. D.</p> <p>2012-12-01</p> <p>Spatial patterns in static sea level are controlled by the interplay between the history of ice mass variations and the associated deformational, gravitational and rotational perturbations in the Earth's state. Over the last decade, there has been a renewed effort to extend classic treatments of ice-age sea-level change (Farrell and Clark, 1976) to incorporate effects such as shoreline migration due to the local onlap or offlap of seawater and changes in the extent of grounded, marine-based ice, as well as feedbacks between sea level and the orientation of Earth's rotation axis. To date, the impact of <span class="hlt">sediment</span> <span class="hlt">transport</span> - whether in the context of glacial processes, or other processes such as fluvial deposition - has not been incorporated into a gravitationally self-consistent sea-level theory. Here we briefly summarize the main elements of a new sea-level theory that includes <span class="hlt">sediment</span> <span class="hlt">transport</span>, and we apply this new theory to investigate crustal deformation and sea-level changes driven by <span class="hlt">sediment</span> deposition on the Mississippi fan in the Gulf of Mexico. The calculations incorporate <span class="hlt">sediment</span> <span class="hlt">transport</span> from the start of the last glacial cycle through to the present and are constrained to conserve <span class="hlt">sediment</span> and ocean mass. We compare relative sea level histories predicted with and without <span class="hlt">sediment</span> <span class="hlt">transport</span> at sites in and around the Gulf of Mexico, and we quantify the relative impacts of gravitational and deformational effects of <span class="hlt">sediment</span> deposition. We also explore the extent to which sea-level changes associated with <span class="hlt">sediment</span> <span class="hlt">transport</span> impact the interpretation of paleo-sea-level records. Our new sea-level formulation provides an important component of a comprehensive coupling between <span class="hlt">sediment</span> transfer and sea level on local, regional and global spatial scales, and on time scales extending from decades to tens of thousands of years. References: Farrell, W.E., and Clark, J.A., 1976. On postglacial sea level: Geophysical Journal of the Royal Astronomical Society, v</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.H41B0295D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.H41B0295D"><span>Prediction of Mass Wasting, Erosion, and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> With the Distributed Hydrology-Soil-Vegetation Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Doten, C. O.; Lanini, J. S.; Bowling, L. C.; Lettenmaier, D. P.</p> <p>2004-12-01</p> <p>Erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> in a temperate forested watershed are predicted with a new <span class="hlt">sediment</span> module linked to the Distributed Hydrology-Soil-Vegetation Model (DHSVM). The DHSVM <span class="hlt">sediment</span> module represents the main sources of <span class="hlt">sediment</span> generation in forested environments: mass wasting, hillslope erosion and road surface erosion. It produces failures based on a factor-of-safety analysis with the infinite slope model through use of stochastically generated soil and vegetation parameters. Failed material is routed downslope with a rule-based scheme that determines <span class="hlt">sediment</span> delivery to streams. <span class="hlt">Sediment</span> from hillslopes and road surfaces is also <span class="hlt">transported</span> to the channel network. Basin <span class="hlt">sediment</span> yield is predicted with a simple channel <span class="hlt">sediment</span> routing scheme. The model was applied to the Rainy Creek catchment, a tributary of the Wenatchee River which drains the east slopes of the Cascade Mountains, and Hard and Ware Creeks on the west slopes of the Cascades. In these initial applications, the model produced plausible <span class="hlt">sediment</span> yield and ratios of landsliding and surface erosion , when compared to published rates for similar catchments in the Pacific Northwest. We have also used the model to examine the implications of fires and logging road removal on <span class="hlt">sediment</span> generation in the Rainy Creek catchment. Generally, in absolute value, the predicted changes (increased <span class="hlt">sediment</span> generation) following fires, which are primarily associated with increased slope failures, are much larger than the modest changes (reductions in <span class="hlt">sediment</span> yield) associated with road obliteration, although the small sensitivity to forest road obliteration may be due in part to the relatively low road density in the Rainy Creek catchment, and to mechanisms, such as culvert failure, that are not represented in the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Geomo.222..143V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Geomo.222..143V"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and mixing depth on a coral reef sand apron</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vila-Concejo, Ana; Harris, Daniel L.; Power, Hannah E.; Shannon, Amelia M.; Webster, Jody M.</p> <p>2014-10-01</p> <p>This paper investigates the mechanics of <span class="hlt">sediment</span> <span class="hlt">transport</span> on a subtidal sand apron located on a coral reef environment. In this environment 100% of the <span class="hlt">sediment</span> is carbonate bioclasts generated in situ. The sand apron is located on the back reef and only affected by waves during high tides. It is commonly accepted in the literature that sand aprons are features that prograde lagoonwards and that most of the progradation occurs during high-energy events. Measurements of water depths, waves, currents and near bed suspended <span class="hlt">sediment</span> concentrations (all at 10 Hz) on the sand apron were undertaken over a nine day intensive field campaign over both spring and neap tides; waves and tides were also measured in the lagoon. The topography and bathymetry of the sand apron were measured and mixing depth was obtained on three transects using depth of disturbance rods. We found that <span class="hlt">sediment</span> <span class="hlt">transport</span> on sand aprons is not solely restricted to high-energy events but occurs on a daily basis during spring tides. The main factor controlling the <span class="hlt">sediment</span> <span class="hlt">transport</span> was the water depth above the bed, with depths of 2-2.3 m allowing waves to promote the most <span class="hlt">sediment</span> <span class="hlt">transport</span>. This corresponds to a depth over the reef crest of 1.6-1.9 m. The second most important control was waves; <span class="hlt">transport</span> was observed when Hs on the apron was 0.1 m or greater. In contrast, current magnitude was not a controlling mechanism for <span class="hlt">sediment</span> entrainment but did affect <span class="hlt">sediment</span> <span class="hlt">transport</span>. The morphology of the sand apron was shown to affect the direction of currents with the currents also expected to influence the morphology of the sand apron. The currents measured during this field campaign were aligned with a shallow channel in the sand apron. Mixing depths were small (< 2.5 cm) yet they were larger than the values predicted by empirical formulae for gentle siliciclastic ocean beaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.3513M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.3513M"><span>Fate and <span class="hlt">Transport</span> of Cohesive <span class="hlt">Sediment</span> and HCB in the Middle Elbe River Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moshenberg, Kari; Heise, Susanne; Calmano, Wolfgang</p> <p>2014-05-01</p> <p>Chemical contamination of waterways and floodplains is a pervasive environmental problem that threatens aquatic ecosystems worldwide. Due to extensive historical contamination and redistribution of contaminated <span class="hlt">sediments</span> throughout the basin, the Elbe River <span class="hlt">transports</span> significant loads of contaminants downstream, particularly during flood events. This study focuses on Hexachlorobenzene (HCB), a persistent organic pollutant that has been identified as a contaminant of concern in the Elbe Basin. To better understand the fate and <span class="hlt">transport</span> of cohesive <span class="hlt">sediments</span> and <span class="hlt">sediment</span>-sorbed HCB, a hydrodynamic, suspended <span class="hlt">sediment</span>, and contaminated <span class="hlt">transport</span> model for the 271-km reach of the Elbe River basin between Dresden and Magdeburg was developed. Additionally, trends in suspended <span class="hlt">sediment</span> and contaminant <span class="hlt">transport</span> were investigated in the context of the recent high frequency of floods in the Elbe Basin. This study presents strong evidence that extreme high water events, such as the August, 2002 floods, have a permanent effect on the <span class="hlt">sediment</span> <span class="hlt">transport</span> regime in the Elbe River. Additionally, results indicate that a significant component annual HCB loads are <span class="hlt">transported</span> downstream during floods. Additionally, modeled results for suspended <span class="hlt">sediment</span> and HCB accumulation on floodplains are presented and discussed. Uncertainty and issues related to model development are also addressed. A worst case analysis of HCB uptake by dairy cows and beef cattle indicate that significant, biologically relevant quantities of <span class="hlt">sediment</span>-sorbed HCB accumulate on the Elbe floodplains following flood events. Given both the recent high frequency of floods in the Elbe Basin, and the potential increase in flood frequency due to climate change, an evaluation of source control measures and/or additional monitoring of floodplain soils and grasses is recommended.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JHyd..420..245K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JHyd..420..245K"><span>Identification of varying time scales in <span class="hlt">sediment</span> <span class="hlt">transport</span> using the Hilbert-Huang Transform method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuai, Ken Z.; Tsai, Christina W.</p> <p>2012-02-01</p> <p>Summary<span class="hlt">Sediment</span> <span class="hlt">transport</span> processes vary at a variety of time scales - from seconds, hours, days to months and years. Multiple time scales exist in the system of flow, <span class="hlt">sediment</span> <span class="hlt">transport</span> and bed elevation change processes. As such, identification and selection of appropriate time scales for flow and <span class="hlt">sediment</span> processes can assist in formulating a system of flow and <span class="hlt">sediment</span> governing equations representative of the dynamic interaction of flow and particles at the desired details. Recognizing the importance of different varying time scales in the fluvial processes of <span class="hlt">sediment</span> <span class="hlt">transport</span>, we introduce the Hilbert-Huang Transform method (HHT) to the field of <span class="hlt">sediment</span> <span class="hlt">transport</span> for the time scale analysis. The HHT uses the Empirical Mode Decomposition (EMD) method to decompose a time series into a collection of the Intrinsic Mode Functions (IMFs), and uses the Hilbert Spectral Analysis (HSA) to obtain instantaneous frequency data. The EMD extracts the variability of data with different time scales, and improves the analysis of data series. The HSA can display the succession of time varying time scales, which cannot be captured by the often-used Fast Fourier Transform (FFT) method. This study is one of the earlier attempts to introduce the state-of-the-art technique for the multiple time sales analysis of <span class="hlt">sediment</span> <span class="hlt">transport</span> processes. Three practical applications of the HHT method for data analysis of both suspended <span class="hlt">sediment</span> and bedload <span class="hlt">transport</span> time series are presented. The analysis results show the strong impact of flood waves on the variations of flow and <span class="hlt">sediment</span> time scales at a large sampling time scale, as well as the impact of flow turbulence on those time scales at a smaller sampling time scale. Our analysis reveals that the existence of multiple time scales in <span class="hlt">sediment</span> <span class="hlt">transport</span> processes may be attributed to the fractal nature in <span class="hlt">sediment</span> <span class="hlt">transport</span>. It can be demonstrated by the HHT analysis that the bedload motion time scale is better represented by the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1037455','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1037455"><span><span class="hlt">Sediment</span> and Hydraulic Measurements with Computed <span class="hlt">Bed</span> <span class="hlt">Load</span> on the Missouri River, Sioux City to Hermann, 2014</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2017-05-01</p> <p>all sites were surveyed three times, separated by at least 4 weeks (or 20% flow difference) between surveys . Multi-beam, acoustic Doppler current...10 3.4 Multi-beam surveys ...37 4.4 Multi-beam surveys</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.H52B0409A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.H52B0409A"><span>Bedload and Total Load <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Equations for Rough Open-Channel Flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abrahams, A. D.; Gao, P.</p> <p>2001-12-01</p> <p>The total <span class="hlt">sediment</span> load <span class="hlt">transported</span> by an open-channel flow may be divided into bedload and suspended load. Bedload <span class="hlt">transport</span> occurs by saltation at low shear stress and by sheetflow at high shear stress. Dimensional analysis is used to identify the dimensionless variables that control the <span class="hlt">transport</span> rate of noncohesive <span class="hlt">sediments</span> over a plane bed, and regression analysis is employed to isolate the significant variables and determine the values of the coefficients. In the general bedload <span class="hlt">transport</span> equation (i.e. for saltation and sheetflow) the dimensionless bedload <span class="hlt">transport</span> rate is a function of the dimensionless shear stress, the friction factor, and an efficiency coefficient. For sheetflow the last term approaches 1, so that the bedload <span class="hlt">transport</span> rate becomes a function of just the dimensionless shear stress and the friction factor. The dimensional analysis indicates that the dimensionless total load <span class="hlt">transport</span> rate is a function of the dimensionless bedload <span class="hlt">transport</span> rate and the dimensionless settling velocity of the <span class="hlt">sediment</span>. Predicted values of the <span class="hlt">transport</span> rates are graphed against the computed values of these variables for 505 flume experiments reported in the literature. These graphs indicate that the equations developed in this study give good unbiased predictions of both the bedload <span class="hlt">transport</span> rate and total load <span class="hlt">transport</span> rate over a wide range of conditions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914112R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914112R"><span>Coupling climate conditions, <span class="hlt">sediment</span> sources and <span class="hlt">sediment</span> <span class="hlt">transport</span> in an alpine basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rainato, Riccardo; Picco, Lorenzo; Cavalli, Marco; Mao, Luca; Neverman, Andrew J.; Tarolli, Paolo</p> <p>2017-04-01</p> <p>In a fluvial system, mountain basins control <span class="hlt">sediment</span> export to the lowland rivers. Hence, the analysis of the erosion processes and <span class="hlt">sediment</span> delivery patterns that act in mountain basins is important. Several studies have investigated the alterations triggered by recent climatic change on the hydrological regime, whilst only a few works have explored the consequences on the <span class="hlt">sediment</span> dynamics. Here we combined and analyzed the quasi-unique dataset of climatic conditions, landscape response, and <span class="hlt">sediment</span> export produced, since 1986 in the Rio Cordon basin (5 km2, Eastern Italian Alps) to examine the <span class="hlt">sediment</span> delivery processes occurring in the last three decades. The temperature, precipitation, and fluvial <span class="hlt">sediment</span> fluxes in the basin were analyzed using continuous measurement executed by a permanent monitoring station, while the landscape evolution was investigated by three <span class="hlt">sediment</span> source inventories established in 1994, 2006, and 2016. Thus, the analysis focused on the trends exhibited during the periods 1986-1993, 1994-2006, and 2007-2015. In terms of climatic conditions, three distinct climate forcing stages can be observed in the periods analyzed: a relatively stable phase (1986-1993), a period characterized by temperature and rainfall fluctuations (1994-2006), and a more recent warmer and wetter phase (2007-2015). In the 1986-1993 period, the fluvial <span class="hlt">sediment</span> fluxes reflected the stable trend exhibited by the climatic conditions. In the subsequent 1994-2006 period, the average temperature and precipitation were in line with that previously observed, although with higher interannual variability. Notwithstanding the climate forcing and the occurrence of high magnitude/low frequency floods that strongly influenced the source areas, between 1994 and 2006 the Rio Cordon basin showed relatively limited erosion activity. Hence, the climatic conditions and the landscape response can only partially explain the strong increase of <span class="hlt">sediment</span> export recorded in the 1994</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMEP53A1012B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMEP53A1012B"><span>A field experiment on the controls of <span class="hlt">sediment</span> <span class="hlt">transport</span> on bedrock erosion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beer, A. R.; Turowski, J. M.; Fritschi, B.; Rieke-Zapp, D.; Campana, L.; Lavé, J.</p> <p>2012-12-01</p> <p>The earth`s surface is naturally shaped by interactions of physical and chemical processes. In mountainous regions with steep topography river incision fundamentally controls the geomorphic evolution of the whole landscape. There, erosion of exposed bedrock sections by fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> is an important mechanism forming mountain river channels. The links between bedload <span class="hlt">transport</span> and bedrock erosion has been firmly established using laboratory experiments. However, there are only few field datasets linking discharge, <span class="hlt">sediment</span> <span class="hlt">transport</span>, impact energy and erosion that can be used for process understanding and model evaluation. To fill this gap, a new measuring setup has been commissioned to raise an appropriate simultaneous dataset of hydraulics, <span class="hlt">sediment</span> <span class="hlt">transport</span> and bedrock erosion at high temporal and spatial resolution. Two natural stone slabs were installed flush with the streambed of the Erlenbach, a gauged stream in the Swiss Pre-Alps. They are mounted upon force sensors recording vertical pressure und downstream shear caused by passing <span class="hlt">sediment</span> particles. The <span class="hlt">sediment</span> <span class="hlt">transport</span> rates can be assessed using geophone plates and an automated moving basket system taking short-term <span class="hlt">sediment</span> samples. These devices are located directly downstream of the stone slabs. Bedrock erosion rates are measured continuously with erosion sensors at sub-millimeter accuracy at three points on each slab. In addition, the whole slab topography is surveyed with photogrammetry and a structured-light 3D scanner after individual flood events. Since the installation in 2011, slab bedrock erosion has been observed during several <span class="hlt">transport</span> events. We discuss the relation between hydraulics, bedload <span class="hlt">transport</span>, resulting pressure forces on the stone slabs and erosion rates. The aim of the study is the derivation of an empirical process law for fluvial bedrock erosion driven by moving <span class="hlt">sediment</span> particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC14B..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC14B..06K"><span>Morphodynamics and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> on the Huanghe (Yellow River) Delta: Work in Progress</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kineke, G. C.; Calson, B.; Chadwick, A. J.; Chen, L.; Hobbs, B. F.; Kumpf, L. L.; Lamb, M. P.; Ma, H.; Moodie, A. J.; Mullane, M.; Naito, K.; Nittrouer, J. A.; Parker, G.</p> <p>2017-12-01</p> <p>Deltas are perhaps the most dynamic of coastal landforms with competing processes that deliver and disperse <span class="hlt">sediment</span>. As part of the NSF Coastal SEES program, an interdisciplinary team of scientists from the US and China are investigating processes that link river and coastal <span class="hlt">sediment</span> <span class="hlt">transport</span> responsible for morphodynamic change of the Huanghe delta- an excellent study site due to its high <span class="hlt">sediment</span> load and long history of natural and engineered avulsions, that is, abrupt shifts in the river course. A fundamental component of the study is a better understanding of <span class="hlt">sediment</span> <span class="hlt">transport</span> physics in a river system that <span class="hlt">transports</span> mostly silt. Through theory and data analysis, we find that fine-grained rivers fail to develop full scale dunes, which results in faster water flow and substantially larger <span class="hlt">sediment</span> fluxes as compared to sandy rivers (e.g. the Mississippi River). We also have developed new models for <span class="hlt">sediment</span>-size dependent entrainment that are needed to make longer term predictions of river <span class="hlt">sedimentation</span> patterns. On the delta front, we are monitoring the high <span class="hlt">sediment</span> flux to the coast, which results in steep foresets and ideal conditions for off-shore <span class="hlt">sediment</span> delivery via gravity flows. These constraints on <span class="hlt">sediment</span> <span class="hlt">transport</span> are being used to develop new theory for where and when rivers avulse - including the effects of variable flood discharge, <span class="hlt">sediment</span> supply, and sea level rise -and how deltas ultimately grow through repeated cycles of lobe development. Flume experiments and field observations are being used to test these models, both in the main channel of the Huanghe and in channels abandoned after historic avulsions. Abandoned channels and floodplains are now dominated by coastal <span class="hlt">sediment</span> <span class="hlt">transport</span> through a combination of wave resuspension and tidal <span class="hlt">transport</span>, settling lag and reverse estuarine circulation. Finally, the field and laboratory tested numerical models are being used as inputs to define a cost curve for efficient avulsion management of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890047793&hterms=methane+gas+used&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmethane%2Bgas%2Bused','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890047793&hterms=methane+gas+used&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmethane%2Bgas%2Bused"><span>Radon as a tracer of biogenic gas equilibration and <span class="hlt">transport</span> from methane-saturated <span class="hlt">sediments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Martens, Christopher S.; Chanton, Jeffrey P.</p> <p>1989-01-01</p> <p>Data on Rn-222 activity in methane-rich gas bubbles from anoxic coastal <span class="hlt">sediments</span> of Cape Lookout Bight, North Carolina, were used to determine gas equilibration with pore waters and the rates of ebullitive stripping and <span class="hlt">transport</span> of gases to overlying waters and the atmosphere. Results showed that, during summer months, the bubble ebullition process strips and <span class="hlt">transports</span> 1.9-4.8 percent/day of the standing crop of radon (and, by inference, other gases equilibrated with gas bubbles) in surface <span class="hlt">sediments</span> of Cape Lookout Bight to the troposphere. Thus, the ebullitive mode of gas <span class="hlt">transport</span> represents an effective mechanism for delivering reduced biogenic gases directly to the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP41A1819L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP41A1819L"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Capacity and Channel Processes in a Humid Tropical Montane River - Rio Pacuare, Costa Rica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lind, P.; McDowell, P. F.</p> <p>2017-12-01</p> <p>Investigating <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity as well as the spatial and temporal variations of <span class="hlt">sediment</span> flux are critical component of river research, especially for applications in resource management and conservation, hazards assessment and planning, and riverine ecology. The bedload fraction of <span class="hlt">sediment</span> <span class="hlt">transported</span> through montane rivers often defines channel and bed form processes. It is understood that humid tropical montane rivers are capable of producing some of the largest quantities of <span class="hlt">sediment</span> per unit drainage area. Bedload flux reported on a few Southeast Asian humid tropical montane rivers show that bedload constituted 16-75% of the total <span class="hlt">sediment</span> load - this is notably higher than the generally accepted 10% of a channel's <span class="hlt">sediment</span> load. However, to date almost all of the research done on <span class="hlt">sediment</span> <span class="hlt">transport</span> in humid tropical systems has focused on suspended load. This study presents annual bedload <span class="hlt">transport</span> rate estimates for six field sites distributed within 45 river kilometers (Rkm) of the montane portion of the Rio Pacuare, located in the Talamanca Mountains of Costa Rica. This research reveals that flows capable of mobilizing the D84 occur on average at least once but often multiple times a year in this river system. The Rio Pacuare has a sufficient supply of <span class="hlt">sediment</span> to meet its high <span class="hlt">transport</span> capacity needs. As a result, large active bars composed of imbricated boulders define channel form at moderate and low flows throughout the study area. Differences in the magnitude, as well as the spatial and temporal variations of <span class="hlt">sediment</span> flux at each field site are discussed in relation to stream power, and annual/inter-annual precipitation patterns. A unique mix of field and remote sensing techniques were applied to address these questions and to overcome some of the challenges of tropical river research. For example, due to the large grain size and high stream energy, grain mobilization and validation of modeled shear stress requirements for <span class="hlt">transport</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3202074','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3202074"><span>Pore Water <span class="hlt">Transport</span> of Enterococci out of Beach <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Phillips, Matthew C.; Solo-Gabriele, Helena M.; Reniers, Adrianus J. H. M.; Wang, John D.; Kiger, Russell T.; Abdel-Mottaleb, Noha</p> <p>2011-01-01</p> <p>Enterococci are used to evaluate the safety of beach waters and studies have identified beach sands as a source of these bacteria. In order to study and quantify the release of microbes from beach <span class="hlt">sediments</span>, flow column systems were built to evaluate flow of pore water out of beach <span class="hlt">sediments</span>. Results show a peak in enterococci (average of 10% of the total microbes in core) released from the sand core within one pore water volume followed by a marked decline to below detection. These results indicate that few enterococci are easily removed and that factors other than simple pore water flow control the release of the majority of enterococci within beach <span class="hlt">sediments</span>. A significantly larger quantity and release of enterococci were observed in cores collected after a significant rain event suggesting the influx of fresh water can alter the release pattern as compared to cores with no antecedent rainfall. PMID:21945015</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/923283','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/923283"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> time measured with U-Series isotopes: Resultsfrom ODP North Atlantic Drill Site 984</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>DePaolo, Donald J.; Maher, Kate; Christensen, John N.</p> <p></p> <p>High precision uranium isotope measurements of marineclastic <span class="hlt">sediments</span> are used to measure the <span class="hlt">transport</span> and storage time ofsediment from source to site of deposition. The approach is demonstratedon fine-grained, late Pleistocene deep-sea <span class="hlt">sediments</span> from Ocean DrillingProgram Site 984A on the Bjorn Drift in the North Atlantic. The sedimentsare siliciclastic with up to 30 percent carbonate, and dated by sigma 18Oof benthic foraminifera. Nd and Sr isotopes indicate that provenance hasoscillated between a proximal source during the last three interglacialperiods volcanic rocks from Iceland and a distal continental sourceduring glacial periods. An unexpected finding is that the 234U/238Uratios of the silicatemore » portion of the <span class="hlt">sediment</span>, isolated by leaching withhydrochloric acid, are significantly less than the secular equilibriumvalue and show large and systematic variations that are correlated withglacial cycles and <span class="hlt">sediment</span> provenance. The 234U depletions are inferredto be due to alpha-recoil loss of234Th, and are used to calculate"comminution ages" of the <span class="hlt">sediment</span> -- the time elapsed between thegeneration of the small (<_ 50 mu-m) <span class="hlt">sediment</span> grains in the sourceareas by comminution of bedrock, and the time of deposition on theseafloor. <span class="hlt">Transport</span> times, the difference between comminution ages anddepositional ages, vary from less than 10 ky to about 300 to 400 ky forthe Site 984A <span class="hlt">sediments</span>. Long <span class="hlt">transport</span> times may reflect prior storagein soils, on continental shelves, or elsewhere on the seafloor. Transporttime may also be a measure of bottom current strength. During the mostrecent interglacial periods the detritus from distal continental sourcesis diluted with <span class="hlt">sediment</span> from Iceland that is rapidly <span class="hlt">transported</span> to thesite of deposition. The comminution age approach could be used to dateQuaternary non-marine <span class="hlt">sediments</span>, soils, and atmospheric dust, and may beenhanced by concomitant measurement of 226Ra/230Th, 230Th/234U, andcosmogenic nuclides.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70044442','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70044442"><span>Geologic evidence for onshore <span class="hlt">sediment</span> <span class="hlt">transport</span> from the inner continental shelf: Fire Island, New York</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schwab, William C.; Baldwin, Wayne E.; Hapke, Cheryl J.; Lentz, Erika E.; Gayes, Paul T.; Denny, Jane F.; List, Jeffrey H.; Warner, John C.</p> <p>2013-01-01</p> <p><span class="hlt">Sediment</span> budget analyses along the south shore of Fire Island, New York, have been conducted and debated in the scientific and coastal engineering literature for decades. It is well documented that a primary component of <span class="hlt">sediment</span> <span class="hlt">transport</span> in this system is directed alongshore from E to W, but discrepancies in volumetric <span class="hlt">sediment</span> budget calculations remain. An additional quantity of sand, averaging about 200,000 m3/y is required to explain the growth of the western segment of the barrier island, a prograding spit. Littoral <span class="hlt">sediment</span> derived from updrift erosion of the coast, addition of beach nourishment fill, and onshore <span class="hlt">transport</span> of inner continental shelf, shoreface <span class="hlt">sediments</span>, or both have all been proposed as potential sources of the additional <span class="hlt">sediment</span> needed to balance the <span class="hlt">sediment</span> budget deficit. Analysis of high-resolution seafloor mapping data collected in 2011, including seismic reflection profiles and inteferometric sonar acoustic backscatter and swath bathymetry; comparison with seafloor mapping data collected in 1996–1997; and shoreline change analysis from 1933 to 2011 support previous suggestions that the inner-shelf Holocene sedimentary deposit is a likely source to resolve this <span class="hlt">sediment</span> budget discrepancy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4366508','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4366508"><span>Onset of <span class="hlt">sediment</span> <span class="hlt">transport</span> is a continuous transition driven by fluid shear and granular creep</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Houssais, Morgane; Ortiz, Carlos P.; Durian, Douglas J.; Jerolmack, Douglas J.</p> <p>2015-01-01</p> <p>Fluid-sheared granular <span class="hlt">transport</span> sculpts landscapes and undermines infrastructure, yet predicting the onset of <span class="hlt">sediment</span> <span class="hlt">transport</span> remains notoriously unreliable. For almost a century, this onset has been treated as a discontinuous transition at which hydrodynamic forces overcome gravity-loaded grain–grain friction. Using a custom laminar-shear flume to image slow granular dynamics deep into the bed, here we find that the onset is instead a continuous transition from creeping to granular flow. This transition occurs inside the dense granular bed at a critical viscous number, similar to granular flows and colloidal suspensions and inconsistent with hydrodynamic frameworks. We propose a new phase diagram for <span class="hlt">sediment</span> <span class="hlt">transport</span>, where ‘bed load’ is a dense granular flow bounded by creep below and suspension above. Creep is characteristic of disordered solids and reminiscent of soil diffusion on hillslopes. Results provide new predictions for the onset and dynamics of <span class="hlt">sediment</span> <span class="hlt">transport</span> that challenge existing models. PMID:25751296</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H24F..01C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H24F..01C"><span>Fine <span class="hlt">Sediment</span> Residency in Streambeds in Southeastern Australia.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Croke, J. C.; Thompson, C. J.; Rhodes, E.</p> <p>2007-12-01</p> <p>A detailed understanding of channel forming and maintenance processes in streams requires some measurement and/or prediction of <span class="hlt">bed</span> <span class="hlt">load</span> <span class="hlt">transport</span> and <span class="hlt">sediment</span> mobility. Traditional field based measurements of such processes are often problematic due to the high discharge characteristics of upland streams. In part to compensate for such difficulties, empirical flow competence equations have also been developed to predict armour or bedform stabilising grain mobility. These equations have been applied to individual reaches to predict the entrainment of a threshold grain size and the vertical extent of flushing. In cobble- and boulder-bed channels the threshold grain size relates to the size of the bedform stabilising grains (eg. D84, D90). This then allows some prediction of when <span class="hlt">transport</span> of the matrix material occurs. The application of Optically Stimulated Luminescence (OSL) dating is considered here as an alternative and innovative way to determine fine <span class="hlt">sediment</span> residency times in stream beds. Age estimates derived from the technique are used to assist in calibrating <span class="hlt">sediment</span> entrainment models to specific channel types and hydrological regimes. The results from a one-dimensional HEC-RAS model indicate that recurrence interval floods exceeding bankfull up to 13 years are competent to mobilise the maximum overlying surface grain sizes at the sites. OSL minimum age model results of well bleached quartz in the fine matrix particles are in general agreement with selected competence equation predictions. The apparent long (100-1400y) burial age of most of the mineral quartz suggests that competent flows are not able to flush all subsurface fine-bed material. Maximum <span class="hlt">bed</span> <span class="hlt">load</span> exchange (flushing) depth was limited to twice the depth of the overlying D90 grain size. Application of OSL in this study provides important insight into the nature of matrix material storage and flushing in mountain streams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016WRR....52.9001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016WRR....52.9001H"><span>Modeling <span class="hlt">sediment</span> <span class="hlt">transport</span> after ditch network maintenance of a forested peatland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haahti, K.; Marttila, H.; Warsta, L.; Kokkonen, T.; Finér, L.; Koivusalo, H.</p> <p>2016-11-01</p> <p>Elevated suspended <span class="hlt">sediment</span> (SS) loads released from peatlands after drainage operations and the resulting negative effect on the ecological status of the receiving water bodies have been widely recognized. Understanding the processes controlling erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> within the ditch network forms a prerequisite for adequate <span class="hlt">sediment</span> control. While numerous experimental studies have been reported in this field, model based assessments are rare. This study presents a modeling approach to investigate <span class="hlt">sediment</span> <span class="hlt">transport</span> in a peatland ditch network. The <span class="hlt">transport</span> model describes bed erosion, rain-induced bank erosion, floc deposition, and consolidation of the bed. Coupled to a distributed hydrological model, <span class="hlt">sediment</span> <span class="hlt">transport</span> was simulated in a 5.2 ha forestry-drained peatland catchment for 2 years after ditch cleaning. Comparing simulation results to measured SS concentrations suggested that the loose peat material, produced during excavation, contributed markedly to elevated SS concentrations immediately after ditch cleaning. Both snowmelt and summer rainstorms contributed critically to annual loads. Springtime peat erosion during snowmelt was driven by ditch flow whereas during summer rainfalls, bank erosion by raindrop impact was identified as an important process. Relating modeling results to observed spatial topographic changes in the ditch network was challenging and the results were difficult to verify. Nevertheless, the model has potential to identify risk areas for erosion. The results demonstrate that modeling is effective in separating the importance of different processes and complements pure experimental approaches. Modeling results can aid planning and designing efficient <span class="hlt">sediment</span> control measures and guide the focus of experimental studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP51D..01I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP51D..01I"><span>Physical Limits on the Predictability of Erosion and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> by Landslides and Debris Flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iverson, R. M.</p> <p>2015-12-01</p> <p>Episodic landslides and debris flows play a key role in sculpting many steep landscapes, and they also pose significant natural hazards. Field evidence, laboratory experiments, and theoretical analyses show that variations in the quantity, speed, and distance of <span class="hlt">sediment</span> <span class="hlt">transport</span> by landslides and debris flows can depend strongly on nuanced differences in initial conditions. Moreover, initial conditions themselves can be strongly dependent on the geological legacy of prior events. The scope of these dependencies is revealed by the results of landslide dynamics experiments [Iverson et al., Science, 2000], debris-flow erosion experiments [Iverson et al., Nature Geosci., 2011], and numerical simulations of the highly destructive 2014 Oso, Washington, landslide [Iverson et al., Earth Planet. Sci. Let., 2015]. In each of these cases, feedbacks between basal <span class="hlt">sediment</span> deformation and pore-pressure generation cause the speed and distance of <span class="hlt">sediment</span> <span class="hlt">transport</span> to be very sensitive to subtle differences in the ambient <span class="hlt">sediment</span> porosity and water content. On the other hand, the onset of most landslides and debris flows depends largely on pore-water pressure distributions and only indirectly on <span class="hlt">sediment</span> porosity and water content. Thus, even if perfect predictions of the locations and timing of landslides and debris flows were available, the dynamics of the events - and their consequent hazards and <span class="hlt">sediment</span> <span class="hlt">transport</span> - would be difficult to predict. This difficulty is a manifestation of the nonlinear physics involved, rather than of poor understanding of those physics. Consequently, physically based models for assessing the hazards and <span class="hlt">sediment</span> <span class="hlt">transport</span> due to landslides and debris flows must take into account both evolving nonlinear dynamics and inherent uncertainties about initial conditions. By contrast, landscape evolution models that use prescribed algebraic formulas to represent <span class="hlt">sediment</span> <span class="hlt">transport</span> by landslides and debris flows lack a sound physical basis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP21G..01P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP21G..01P"><span><span class="hlt">Sediment</span> Connectivity and <span class="hlt">Transport</span> Pathways in Tidal Inlets: a Conceptual Framework with Application to Ameland Inlet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pearson, S.; van Prooijen, B. C.; Zheng Bing, W.; Bak, J.</p> <p>2017-12-01</p> <p>Predicting the response of tidal inlets and adjacent coastlines to sea level rise and anthropogenic interventions (e.g. sand nourishments) requires understanding of <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways. These pathways are strongly dependent on hydrodynamic forcing, grain size, underlying morphology, and the timescale considered. To map and describe these pathways, we considered the concept of <span class="hlt">sediment</span> connectivity, which quantifies the degree to which <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways link sources to receptors. In this study we established a framework for understanding <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways in coastal environments, using Ameland Inlet in the Dutch Wadden Sea as a basis. We used the Delft3D morphodynamic model to assess the fate of <span class="hlt">sediment</span> as it moved between specific morphological units defined in the model domain. Simulation data was synthesized in a graphical network and then graph theory used to analyze connectivity at different space and time scales. At decadal time scales, fine and very fine sand (<250μm) have greater connectivity with receptor areas further away from their sources. Conversely, medium sand (>250μm) shows lower connectivity, even in more energetic areas. Greater <span class="hlt">sediment</span> connectivity was found under the influence of wind and waves when compared to purely tidal forcing. Connectivity shows considerable spatial variation in cross shore and alongshore directions, depending on proximity to the inlet and dominant wave direction. Furthermore, connectivity generally increases at longer timescales. Asymmetries in connectivity (i.e. unidirectional <span class="hlt">transport</span>) can be used to explain long-term erosional or depositional trends. As such, an understanding of <span class="hlt">sediment</span> connectivity as a function of grain size could yield useful insights for resolving <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways and the fate of a nourishment in coastal environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2008/5186/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2008/5186/"><span>Sources, <span class="hlt">Transport</span>, and Storage of <span class="hlt">Sediment</span> at Selected Sites in the Chesapeake Bay Watershed</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gellis, Allen C.; Hupp, Cliff R.; Pavich, Milan J.; Landwehr, Jurate M.; Banks, William S.L.; Hubbard, Bernard E.; Langland, Michael J.; Ritchie, Jerry C.; Reuter, Joanna M.</p> <p>2009-01-01</p> <p>The Chesapeake Bay Watershed covers 165,800 square kilometers and is supplied with water and <span class="hlt">sediment</span> from five major physiographic provinces: Appalachian Plateau, Blue Ridge, Coastal Plain, Piedmont, and the Valley and Ridge. Suspended-<span class="hlt">sediment</span> loads measured in the Chesapeake Bay Watershed showed that the Piedmont Physiographic Province has the highest rates of modern (20th Century) <span class="hlt">sediment</span> yields, measured at U.S. Geological Survey streamflow-gaging stations, and the lowest rates of background or geologic rates of erosion (~10,000 years) measured with in situ beryllium-10. In the agricultural and urbanizing Little Conestoga Creek Watershed, a Piedmont watershed, sources of <span class="hlt">sediment</span> using the '<span class="hlt">sediment</span>-fingerprinting' approach showed that streambanks were the most important source (63 percent), followed by cropland (37 percent). Cesium-137 inventories, which quantify erosion rates over a 40-year period, showed average cropland erosion of 19.39 megagrams per hectare per year in the Little Conestoga Creek Watershed. If this erosion rate is extrapolated to the 13 percent of the watershed that is in cropland, then cropland could contribute almost four times the measured suspended-<span class="hlt">sediment</span> load <span class="hlt">transported</span> out of the watershed (27,600 megagrams per hectare per year), indicating that much of the eroded <span class="hlt">sediment</span> is being deposited in channel and upland storage. The Piedmont has had centuries of land-use change, from forest to agriculture, to suburban and urban areas, and in some areas, back to forest. These land-use changes mobilized a large percentage of <span class="hlt">sediment</span> that was deposited in upland and channel storage, and behind thousands of mill dams. The effects of these land-use changes on erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> are still being observed today as stored <span class="hlt">sediment</span> in streambanks is a source of <span class="hlt">sediment</span>. Cropland is also an important source of <span class="hlt">sediment</span>. The Coastal Plain Physiographic Province has had the lowest <span class="hlt">sediment</span> yields in the 20th Century and with sandy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H53I..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H53I..02S"><span>Linking suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> metrics with fish functional traits in the Northwestern Great Plains (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwartz, J. S.; Simon, A.; Klimetz, L.</p> <p>2009-12-01</p> <p>Loss of ecological integrity due to excessive suspended <span class="hlt">sediment</span> in rivers and streams is a major cause of water quality impairment in the United States. Although 32 states have developed numeric criteria for turbidity or suspended solids, or both according to the USEPA (2006), criteria is typically written as a percent exceedance above background and what constitutes background is not well defined. Defining a background level is problematic considering suspended <span class="hlt">sediments</span> and related turbidity levels change with flow stage and season, and limited scientific data exists on relationships between <span class="hlt">sediment</span> exposure and biotic response. Current assessment protocols for development of <span class="hlt">sediment</span> total maximum daily loads (TMDLs) lack a means to link temporally-variable <span class="hlt">sediment</span> <span class="hlt">transport</span> rates with specific losses of ecological functions as loads increase. This study, within the in Northwestern Great Plains Ecoregion, co-located 58 USGS gauging stations with existing flow and suspended <span class="hlt">sediment</span> data, and fish data from federal and state agencies. Suspended <span class="hlt">sediment</span> concentration (SSC) <span class="hlt">transport</span> metrics were quantified into exceedance frequencies of a given magnitude, duration as the number of consecutive days a given concentration was equaled or exceeded, dosage as concentration x duration, and mean annual suspended <span class="hlt">sediment</span> yields. A functional traits-based approach was used to correlate SSC <span class="hlt">transport</span> metrics with site occurrences of 20 fish traits organized into four main groups: preferred rearing mesohabitat, trophic structure, feeding habits, and spawning behavior. Negative correlations between SSC metrics and trait occurrences were assumed to represent potential conditions for impairment, specifically identifying an ecological loss by functional trait. Potential impairment conditions were linked with presence of the following traits: habitat preferences for stream pool and river shallow waters; feeding generalists, omnivores, piscivores; and several spawning</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP34C..06M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP34C..06M"><span>Monitoring suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in an ice-affected river using acoustic Doppler current profilers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, S. A.; Ghareh Aghaji Zare, S.; Rennie, C. D.; Ahmari, H.; Seidou, O.</p> <p>2013-12-01</p> <p>Quantifying <span class="hlt">sediment</span> budgets and understanding the processes which control fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> is paramount to monitoring river geomorphology and ecological habitat. In regions that are subject to freezing there is the added complexity of ice. River ice processes impact flow distribution, water stage and <span class="hlt">sediment</span> <span class="hlt">transport</span>. Ice processes typically have the largest impact on <span class="hlt">sediment</span> <span class="hlt">transport</span> and channel morphodynamics when ice jams occur during ice cover formation and breakup. Ice jams may restrict flow and cause local acceleration when released. Additionally, ice can mechanically scour river bed and banks. Under-ice <span class="hlt">sediment</span> <span class="hlt">transport</span> measurements are lacking due to obvious safety and logistical reasons, in addition to a lack of adequate measurement techniques. Since some rivers can be covered in ice during six months of the year, the lack of data in winter months leads to large uncertainty in annual <span class="hlt">sediment</span> load calculations. To address this problem, acoustic profilers are being used to monitor flow velocity, suspended <span class="hlt">sediment</span> and ice processes in the Lower Nelson River, Manitoba, Canada. Acoustic profilers are ideal for under-ice <span class="hlt">sediment</span> flux measurements since they can be operated autonomously and continuously, they do not disturb the flow in the zone of measurement and acoustic backscatter can be related to <span class="hlt">sediment</span> size and concentration. In March 2012 two upward-facing profilers (1200 kHz acoustic Doppler current profiler, 546 KHz acoustic backscatter profiler) were installed through a hole in the ice on the Nelson River, 50 km downstream of the Limestone Generating Station. Data were recorded for four months, including both stable cover and breakup periods. This paper presents suspended <span class="hlt">sediment</span> fluxes calculated from the acoustic measurements. Velocity data were used to infer the vertical distribution of <span class="hlt">sediment</span> sizes and concentrations; this information was then used in the interpretation of the backscattered intensity data. It was found that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=323891','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=323891"><span>Simulation and control of <span class="hlt">sediment</span> <span class="hlt">transport</span> due to dam removal</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>This paper presents two case studies of post dam removal <span class="hlt">sedimentation</span> in the United States. Two different one-dimensional channel evolution simulation models were used: CCHE1D and CONCEPTS, respectively. The first case is the application of CCHE1D to assess a long-term morphological response to the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019192','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019192"><span>Shifting sources and <span class="hlt">transport</span> paths for the late Quaternary Escanaba Trough <span class="hlt">sediment</span> fill (northeast Pacific)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zuffa, G.G.; De Rosa, R.; Normark, W.R.</p> <p>1997-01-01</p> <p>Escanaba Trough, which forms the southernmost part of the axial valley of the actively spreading Gorda Ridge, is filled with several hundred meters of <span class="hlt">sediment</span> of presumed late Quaternary age. Surficial <span class="hlt">sediment</span> samples from gravity cores, deeper samples (as much as 390 m) from Site 35 of the Deep Sea Drilling Program (Leg 5), and the acoustic character of the <span class="hlt">sediment</span> fill observed on seismic-reflection profiles indicate that much of the <span class="hlt">sediment</span> fill is of turbidite origin. Gross composition and heavy- mineral analyses of sand samples show that two distinct petrofacies comprise the <span class="hlt">sediment</span> fill. The lower part of the fill was derived primarily from the Klamath River source of northern California while the younger fill, including the surficial sand beds, are from the Columbia River drainage much farther north. The Escanaba Trough <span class="hlt">sediment</span> provides an opportunity to evaluate concepts for paleogeographic and paleotectonic reconstructions that are based on facies analysis and compositional and textural data for the volcanic components because both intrabasinal and extrabasinal sources are present as well as coeval (neovolcanic) and non coeval (paleovolcanic) sourcre This study of a modern basin shows, that although the <span class="hlt">sediment</span> sources could be identified, it was useful to have some knowledge of the <span class="hlt">sediment</span> pathway(s), the effects of diagenesis, and the possible effects of <span class="hlt">sediment</span> sorting as a result of long <span class="hlt">transport</span> distances from the source area for some components. Application of these same techniques to ancient deposits without benefit of the additional parameters will face limitations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29538335','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29538335"><span>Erosion and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Modelling in Shallow Waters: A Review on Approaches, Models and Applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hajigholizadeh, Mohammad; Melesse, Assefa M; Fuentes, Hector R</p> <p>2018-03-14</p> <p>The erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The <span class="hlt">transport</span> mechanism caused by the consequent rainfall-runoff process determines the amount of generated <span class="hlt">sediment</span> that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning <span class="hlt">sediment</span> <span class="hlt">transport</span> modelling in shallow waters. A classification based on the representational processes of the soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5877063','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5877063"><span>Erosion and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Modelling in Shallow Waters: A Review on Approaches, Models and Applications</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fuentes, Hector R.</p> <p>2018-01-01</p> <p>The erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> processes in shallow waters, which are discussed in this paper, begin when water droplets hit the soil surface. The <span class="hlt">transport</span> mechanism caused by the consequent rainfall-runoff process determines the amount of generated <span class="hlt">sediment</span> that can be transferred downslope. Many significant studies and models are performed to investigate these processes, which differ in terms of their effecting factors, approaches, inputs and outputs, model structure and the manner that these processes represent. This paper attempts to review the related literature concerning <span class="hlt">sediment</span> <span class="hlt">transport</span> modelling in shallow waters. A classification based on the representational processes of the soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> models (empirical, conceptual, physical and hybrid) is adopted, and the commonly-used models and their characteristics are listed. This review is expected to be of interest to researchers and soil and water conservation managers who are working on erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> phenomena in shallow waters. The paper format should be helpful for practitioners to identify and generally characterize the types of available models, their strengths and their basic scope of applicability. PMID:29538335</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70148391','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70148391"><span>Integrating geophysical and oceanographic data to assess interannual variability in longshore <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Miselis, Jennifer L.; Long, Joseph W.; Dalyander, P. Soupy; Flocks, James G.; Buster, Noreen A.; Mickey, Rangley</p> <p>2015-01-01</p> <p>Despite their utility for prediction of coastal behavior and for coastal management, littoral <span class="hlt">sediment</span> budgets are difficult to quantify over large regions of coastline and over short time scales. In this study, bathymetric change analysis shows differences in the magnitude and spatial location of erosion and accretion over three years; more net accumulation occurred at the littoral end point of the system in the second year (2012-2013) compared to the first (2011-2012). However, the estimated magnitude of longshore <span class="hlt">transport</span> based on wave characteristics was lower in the second year than for the first year. Similarly, comparisons of total water levels and island elevation over the study period show increased number of overwash hours in the second year, indicating increased cross-shore <span class="hlt">sediment</span> losses and presumably less <span class="hlt">sediment</span> <span class="hlt">transported</span> alongshore. The storm-mediated degradation of the man-made northern portion of the island resulting in increased sub-aqueous <span class="hlt">sediment</span> availability may explain the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2015/5127/sir20155127.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2015/5127/sir20155127.pdf"><span>Characteristics of <span class="hlt">sediment</span> <span class="hlt">transport</span> at selected sites along the Missouri River, 2011–12</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rus, David L.; Galloway, Joel M.; Alexander, Jason S.</p> <p>2015-10-22</p> <p>The Modified-Einstein Procedure tended to predict greater total-<span class="hlt">sediment</span> loads when compared to measured values. These differences may be the result of <span class="hlt">sediment</span> deficits in the Missouri River that lead to an overprediction by the Modified-Einstein Procedure, the unsampled zone above the streambed that leads to an underprediction by the suspended sampler, or general uncertainty in the sampling approach. The differences between total-<span class="hlt">sediment</span> load obtained through measurements and that estimated from applied theoretical procedures such as the Modified-Einstein Procedure pose a challenge for reliably characterizing total-<span class="hlt">sediment</span> <span class="hlt">transport</span>. Though it is not clear which of the two techniques is more accurate, the general tendency of the two to be within an order of magnitude of one another may be adequate for many <span class="hlt">sediment</span> studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6866218-sedimentation-central-segment-aleutian-trench-sources-transport-depositional-style','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6866218-sedimentation-central-segment-aleutian-trench-sources-transport-depositional-style"><span><span class="hlt">Sedimentation</span> in the central segment of the Aleutian Trench: Sources, <span class="hlt">transport</span>, and depositional style</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stevenson, A.J.; Scholl, D.W.; Vallier, T.L.</p> <p>1990-05-01</p> <p>The central segment of the Aleutian Trench (162{degree}W to 175{degree}E) is an intraoceanic subduction zone that contains an anomalously thick sedimentary fill (4 km maximum). The fill is an arcward-thickening and slightly tilted wedge of <span class="hlt">sediment</span> characterized acoustically by laterally continuous, closely spaced, parallel reflectors. These relations are indicative of turbidite deposition. The trench floor and reflection horizons are planar, showing no evidence of an axial channel or any transverse fan bodies. Cores of surface <span class="hlt">sediment</span> recover turbidite layers, implying that <span class="hlt">sediment</span> <span class="hlt">transport</span> and deposition occur via diffuse, sheetlike, fine-grained turbidite flows that occupy the full width of the trench.more » The mineralogy of Holocene trench <span class="hlt">sediments</span> document a mixture of island-arc (dominant) and continental source terranes. GLORIA side-scan sonar images reveal a westward-flowing axial trench channel that conducts <span class="hlt">sediment</span> to the eastern margin of the central segment, where channelized flow cases. Much of the <span class="hlt">sediment</span> <span class="hlt">transported</span> in this channel is derived from glaciated drainages surrounding the Gulf of Alaska which empty into the eastern trench segment via deep-sea channel systems (Surveyor and others) and submarine canyons (Hinchinbrook and others). Insular <span class="hlt">sediment</span> <span class="hlt">transport</span> is more difficult to define. GLORIA images show the efficiency with which the actively growing accretionary wedge impounds <span class="hlt">sediment</span> that manages to cross a broad fore-arc terrace. It is likely that island-arc <span class="hlt">sediment</span> reaches the trench either directly via air fall, via recycling of the accretionary prism, or via overtopping of the accretionary ridges by the upper parts of thick turbidite flows.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70178652','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70178652"><span>Observations of pockmark flow structure in Belfast Bay, Maine, Part 3: implications for <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L.</p> <p>2017-01-01</p> <p>Current observations and <span class="hlt">sediment</span> characteristics acquired within and along the rim of two pockmarks in Belfast Bay, Maine, were used to characterize periods of <span class="hlt">sediment</span> <span class="hlt">transport</span> and to investigate conditions favorable to the settling of suspended <span class="hlt">sediment</span>. Hourly averaged Shields parameters determined from horizontal current velocity profiles within the center of each pockmark never exceed the critical value (approximated with the theoretical model of Dade et al. 1992). However, Shields parameters estimated at the pockmark rims periodically exceed the critical value, consistent with conditions that support the onset of <span class="hlt">sediment</span> <span class="hlt">transport</span> and suspension. Below the rim in the near-center of each pockmark, depth-averaged vertical velocities were less than zero (downward) 60% and 55% of the time in the northern and southern pockmarks, and were often comparable to depth-averaged horizontal velocities. Along the rim, depth-averaged vertical velocities over the lower 8 m of the water column were primarily downward but much less than depth-averaged horizontal velocities indicating that suspended <span class="hlt">sediment</span> may be moved to distant locations. Maximum grain sizes capable of remaining in suspension under terminal settling flow conditions (ranging 10–170 μm) were typically much greater than the observed median grain diameter (about 7 μm) at the bed. During upwelling flow within the pockmarks, and in the absence of flocculation, suspended <span class="hlt">sediment</span> would not settle. The greater frequency of predicted periods of <span class="hlt">sediment</span> <span class="hlt">transport</span> along the rim of the southern pockmark is consistent with pockmark morphology in Belfast Bay, which transitions from more spherical to more elongated toward the south, suggesting near-bed <span class="hlt">sediment</span> <span class="hlt">transport</span> may contribute to post-formation pockmark evolution during typical conditions in Belfast Bay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70190352','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70190352"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and deposition on a river-dominated tidal flat: An idealized model study</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sherwood, Christopher R.; Chen, Shih-Nan; Geyer, W. Rockwell; Ralston, David K.</p> <p>2010-01-01</p> <p>A 3-D hydrodynamic model is used to investigate how different size classes of river-derived <span class="hlt">sediment</span> are <span class="hlt">transported</span>, exported and trapped on an idealized, river-dominated tidal flat. The model is composed of a river channel flanked by sloping tidal flats, a configuration motivated by the intertidal region of the Skagit River mouth in Washington State, United States. It is forced by mixed tides and a pulse of freshwater and <span class="hlt">sediment</span> with various settling velocities. In this system, the river not only influences stratification but also contributes a significant cross-shore <span class="hlt">transport</span>. As a result, the bottom stress is strongly ebb-dominated in the channel because of the seaward advance of strong river flow as the tidal flats drain during ebbs. <span class="hlt">Sediment</span> deposition patterns and mass budgets are sensitive to settling velocity. The lateral <span class="hlt">sediment</span> spreading scales with an advective distance (settling time multiplied by lateral flow speed), thereby confining the fast settling <span class="hlt">sediment</span> classes in the channel. Residual <span class="hlt">sediment</span> <span class="hlt">transport</span> is landward on the flats, because of settling lag, but is strongly seaward in the channel. The seaward <span class="hlt">transport</span> mainly occurs during big ebbs and is controlled by a length scale ratio Ld/XWL, where Ld is a cross-shore advective distance (settling time multiplied by river outlet velocity), and XWL is the immersed cross-shore length of the intertidal zone. <span class="hlt">Sediment</span> trapping requires Ld/XWL < 1, leading to more trapping for the faster settling classes. Sensitivity studies show that including stratification and reducing tidal range both favor <span class="hlt">sediment</span> trapping, whereas varying channel geometries and asymmetry of tides has relatively small impacts. Implications of the modeling results on the south Skagit intertidal region are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8429P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8429P"><span>Modeling the <span class="hlt">sediment</span> <span class="hlt">transport</span> induced by deep sea mining in the Pacific Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Purkiani, Kaveh; Paul, André; Schulz, Michael; Vink, Annemiek; Walter, Maren</p> <p>2017-04-01</p> <p>A numerical modeling study is conducted in the German license area in northeastern Pacific Ocean to investigate the <span class="hlt">sediment</span> dispersal of mining exploitation. A <span class="hlt">sediment</span> <span class="hlt">transport</span> module is implemented in a hydrodynamic model. All differently sized particles can aggregate and break up until equilibrium floc sizes are obtained. A nested model approach using the MITgcm (Massachusetts Institute of Technology general circulation model) is applied and validated against hydrographic and hydrodynamic measurements obtained in this region. Two different <span class="hlt">sediment</span> discharge scenarios have been examined to investigate the effect of flocculation on <span class="hlt">sediment</span> <span class="hlt">transport</span> distribution in the deep ocean. The suspended <span class="hlt">sediment</span> is mainly influenced by a dominant SW current far away from the <span class="hlt">sediment</span> discharge location. Independent of initial particle size all initial particles larger than 30 μm attain similar floc size equilibrium. In contrast to coastal seas and estuaries where floc size equilibrium can be obtained in a few hours, due to low shear rate (G) the flocculation process at deep ocean is completed within 1˜2 days. Considering temporal evolution of the floc size in the model, an increase in floc sinking velocity consequently enhances the <span class="hlt">sediment</span> deposition at seafloor. The analysis of different <span class="hlt">sediment</span> concentration scenarios suggests that floc sinking velocity increases at higher suspended <span class="hlt">sediment</span> concentration (SSC). The presence of a dominant current in this region induces a fine <span class="hlt">sediment</span> plume in SW direction. The dispersed SSC plume at 20 km downstream the discharge location is able to form the flocculation process and induces a spatial variation of floc size and floc sinking velocity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70176469','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70176469"><span>Storm-induced inner-continental shelf circulation and <span class="hlt">sediment</span> <span class="hlt">transport</span>: Long Bay, South Carolina</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Warner, John C.; Armstrong, Brandy N.; Sylvester, Charlene S.; Voulgaris, George; Nelson, Tim; Schwab, William C.; Denny, Jane F.</p> <p>2012-01-01</p> <p>Long Bay is a <span class="hlt">sediment</span>-starved, arcuate embayment located along the US East Coast connecting both South and North Carolina. In this region the rates and pathways of <span class="hlt">sediment</span> <span class="hlt">transport</span> are important because they determine the availability of <span class="hlt">sediments</span> for beach nourishment, seafloor habitat, and navigation. The impact of storms on <span class="hlt">sediment</span> <span class="hlt">transport</span> magnitude and direction were investigated during the period October 2003–April 2004 using bottom mounted flow meters, acoustic backscatter sensors and rotary sonars deployed at eight sites offshore of Myrtle Beach, SC, to measure currents, water levels, surface waves, salinity, temperature, suspended <span class="hlt">sediment</span> concentrations, and bedform morphology. Measurements identify that <span class="hlt">sediment</span> mobility is caused by waves and wind driven currents from three predominant types of storm patterns that pass through this region: (1) cold fronts, (2) warm fronts and (3) low-pressure storms. The passage of a cold front is accompanied by a rapid change in wind direction from primarily northeastward to southwestward. The passage of a warm front is accompanied by an opposite change in wind direction from mainly southwestward to northeastward. Low-pressure systems passing offshore are accompanied by a change in wind direction from southwestward to southeastward as the offshore storm moves from south to north.During the passage of cold fronts more <span class="hlt">sediment</span> is <span class="hlt">transported</span> when winds are northeastward and directed onshore than when the winds are directed offshore, creating a net <span class="hlt">sediment</span> flux to the north–east. Likewise, even though the warm front has an opposite wind pattern, net <span class="hlt">sediment</span> flux is typically to the north–east due to the larger fetch when the winds are northeastward and directed onshore. During the passage of low-pressure systems strong winds, waves, and currents to the south are sustained creating a net <span class="hlt">sediment</span> flux southwestward. During the 3-month deployment a total of 8 cold fronts, 10 warm fronts, and 10 low</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2009/5228/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2009/5228/"><span><span class="hlt">Sediment</span> Characteristics and <span class="hlt">Transport</span> in the Kootenai River White Sturgeon Critical Habitat near Bonners Ferry, Idaho</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fosness, Ryan L.; Williams, Marshall L.</p> <p>2009-01-01</p> <p>Recovery efforts for the endangered Kootenai River population of white sturgeon require an understanding of the characteristics and <span class="hlt">transport</span> of suspended and bedload <span class="hlt">sediment</span> in the critical habitat reach of the river. In 2007 and 2008, the U.S. Geological Survey in cooperation with the Kootenai Tribe of Idaho, conducted suspended- and bedload-<span class="hlt">sediment</span> sampling in the federally designated critical habitat of the endangered Kootenai River white sturgeon population. Three <span class="hlt">sediment</span>-sampling sites were selected that represent the hydraulic differences in the critical habitat. Suspended- and bedload-<span class="hlt">sediment</span> samples along with acoustic Doppler current profiles were collected at these sites during specific river discharges. Samples were analyzed to determine suspended- and bedload-<span class="hlt">sediment</span> characteristics and <span class="hlt">transport</span> rates. <span class="hlt">Sediment</span> <span class="hlt">transport</span> data were analyzed to provide total loading estimates for suspended and bedload <span class="hlt">sediment</span> in the critical habitat reach. Total suspended-<span class="hlt">sediment</span> discharge primarily occurred as fine material that moved through the system in suspension. Total suspended-<span class="hlt">sediment</span> discharge ranged from about 300 metric tons per day to more than 23,000 metric tons per day. Total suspended <span class="hlt">sediment</span> remained nearly equal throughout the critical habitat, with the exception of a few cases where mass wasting of the banks may have caused sporadic spikes in total suspended <span class="hlt">sediment</span>. Bedload-<span class="hlt">sediment</span> discharge averaged 0-3 percent of the total loading. These bedload discharges ranged from 0 to 271 tons per day. The bedload discharge in the upper part of the critical habitat primarily consisted of fine to coarse gravel. A decrease in river competence in addition to an armored channel may be the cause of this limited bedload discharge. The bedload discharge in the middle part of the white sturgeon critical habitat varied greatly, depending on the extent of the backwater from Kootenay Lake. A large quantity of fine-to-coarse gravel is present in the braided</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Geomo.287..116M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Geomo.287..116M"><span>Temporal dynamics of suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in a glacierized Andean basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mao, Luca; Carrillo, Ricardo</p> <p>2017-06-01</p> <p>Suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> can affect water quality and aquatic ecosystems, and its quantification is of the highest importance for river and watershed management. Suspended <span class="hlt">sediment</span> concentration (SSC) and discharge were measured at two locations in the Estero Morales, a Chilean Andean stream draining a small basin (27 km2) hosting glacierized areas of about 1.8 km2. Approximately half of the suspended <span class="hlt">sediment</span> yield (470 t year- 1 km- 2) was <span class="hlt">transported</span> during the snowmelt period and half during glacier melting. The hysteresis patterns between discharge and SSC were calculated for each daily hydrograph and were analysed to shed light on the location and activity of different <span class="hlt">sediment</span> sources at the basin scale. During snowmelt, an unlimited supply of fine <span class="hlt">sediments</span> is provided in the lower and middle part of the basin and hysteresis patterns tend to be clockwise as the peaks in SSC precede the peak of discharge in daily hydrographs. Instead, during glacier melting the source of fine <span class="hlt">sediments</span> is the proglacial area, producing counterclockwise hysteresis. It is suggested that the analysis of hysteretic patterns over time provides a simple concept for interpreting variability of location and activity of <span class="hlt">sediment</span> sources at the basin scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3343S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3343S"><span>Basic problems and new potentials in monitoring <span class="hlt">sediment</span> <span class="hlt">transport</span> using Japanese pipe type geophone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakajo, Saiichi</p> <p>2016-04-01</p> <p>The authors have conducted a lot of series of monitoring of <span class="hlt">sediment</span> <span class="hlt">transport</span> by pipe type geophone in a model hydrological channel with various gradients and water discharge, using the various size of particles from 2 to 21 mm in the diameter. In the case of casting soils particle by particle into the water channel, 1,000 test cases were conducted. In the case of casting all soils at a breath into the water channel, 100 test cases were conducted. The all test results were totally analyzed by the conventional method, with visible judgement by video pictures. Then several important basic problems were found in estimating the volume and particle distributions by the conventional method, which was not found in the past similar studies. It was because the past studies did not consider the types of collisions between <span class="hlt">sediment</span> particle and pipe. Based on these experiments, the authors have firstly implemented this idea into the old formula to estimate the amount of <span class="hlt">sediment</span> <span class="hlt">transport</span>. In the formula, two factors of 1) the rate of sensing in a single collision and 2) the rate of collided particles to a cast all soil particles were concretely considered. The parameters of these factors could be determined from the experimental results and it was found that the obtained formula could estimate grain size distribution. In this paper, they explain the prototype formula to estimate a set of volume and distribution of <span class="hlt">sediment</span> <span class="hlt">transport</span>. Another finding in this study is to propose a single collision as a river index to recognize its characteristics of <span class="hlt">sediment</span> <span class="hlt">transport</span>. This result could characterize the risk ranking of <span class="hlt">sediment</span> <span class="hlt">transport</span> in the rivers and mudflow in the mountainous rivers. Furthermore, in this paper the authors explain how the preciseness of the pipe geophone to sense the smaller <span class="hlt">sediment</span> particles shall be improved, which has never been able to be sensed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024589','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024589"><span>Fluvial <span class="hlt">sediment</span> <span class="hlt">transport</span> and deposition following the 1991 eruption of Mount Pinatubo</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hayes, S.K.; Montgomery, D.R.; Newhall, C.G.</p> <p>2002-01-01</p> <p>The 1991 eruption of Mount Pinatubo generated extreme <span class="hlt">sediment</span> yields from watersheds heavily impacted by pyroclastic flows. Bedload sampling in the Pasig-Potrero River, one of the most heavily impacted rivers, revealed negligible critical shear stress and very high <span class="hlt">transport</span> rates that reflected an essentially unlimited <span class="hlt">sediment</span> supply and the enhanced mobility of particles moving over a smooth, fine-grained bed. Dimensionless bedload <span class="hlt">transport</span> rates in the Pasig-Potrero River differed substantially from those previously reported for rivers in temperate regions for the same dimensionless shear stress, but were similar to rates identified in rivers on other volcanoes and ephemeral streams in arid environments. The similarity between volcanically disturbed and arid rivers appears to arise from the lack of an armored bed surface due to very high relative <span class="hlt">sediment</span> supply; in arid rivers, this is attributed to a flashy hydrograph, whereas volcanically disturbed rivers lack armoring due to sustained high rates of <span class="hlt">sediment</span> delivery. This work suggests that the increases in <span class="hlt">sediment</span> supply accompanying massive disturbance induce morphologic and hydrologic changes that temporarily enhance <span class="hlt">transport</span> efficiency until the watershed recovers and <span class="hlt">sediment</span> supply is reduced. ?? 2002 Elsevier Science B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H51N1596K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H51N1596K"><span>Comparison between Measured and Calculated <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Rates in North Fork Caspar Creek, California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, T. W.; Yarnell, S. M.; Yager, E.; Leidman, S. Z.</p> <p>2015-12-01</p> <p>Caspar Creek is a gravel-bedded stream located in the Jackson Demonstration State Forest in the coast range of California. The Caspar Creek Experimental Watershed has been actively monitored and studied by the Pacific Southwest Research Station and California Department of Forestry and Fire Protection for over five decades. Although total annual <span class="hlt">sediment</span> yield has been monitored through time, <span class="hlt">sediment</span> <span class="hlt">transport</span> during individual storm events is less certain. At a study site on North Fork Caspar Creek, cross-section averaged <span class="hlt">sediment</span> flux was collected throughout two storm events in December 2014 and February 2015 to determine if two commonly used <span class="hlt">sediment</span> <span class="hlt">transport</span> equations—Meyer-Peter-Müller and Wilcock—approximated observed bedload <span class="hlt">transport</span>. Cross-section averaged bedload samples were collected approximately every hour during each storm event using a Helley-Smith bedload sampler. Five-minute composite samples were collected at five equally spaced locations along a cross-section and then sieved to half-phi sizes to determine the grain size distribution. The measured <span class="hlt">sediment</span> flux values varied widely throughout the storm hydrographs and were consistently less than two orders of magnitude in value in comparison to the calculated values. Armored bed conditions, changing hydraulic conditions during each storm and variable <span class="hlt">sediment</span> supply may have contributed to the observed differences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMNG43A..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMNG43A..03W"><span>Turbulent Flow and Sand Dune Dynamics: Identifying Controls on Aeolian <span class="hlt">Sediment</span> <span class="hlt">Transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weaver, C. M.; Wiggs, G.</p> <p>2007-12-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> models are founded on cubic power relationships between the <span class="hlt">transport</span> rate and time averaged flow parameters. These models have achieved limited success and recent aeolian and fluvial research has focused on the modelling and measurement of <span class="hlt">sediment</span> <span class="hlt">transport</span> by temporally varying flow conditions. Studies have recognised turbulence as a driving force in <span class="hlt">sediment</span> <span class="hlt">transport</span> and have highlighted the importance of coherent flow structures in <span class="hlt">sediment</span> <span class="hlt">transport</span> systems. However, the exact mechanisms are still unclear. Furthermore, research in the fluvial environment has identified the significance of turbulent structures for bedform morphology and spacing. However, equivalent research in the aeolian domain is absent. This paper reports the findings of research carried out to characterise the importance of turbulent flow parameters in aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> and determine how turbulent energy and turbulent structures change in response to dune morphology. The relative importance of mean and turbulent wind parameters on aeolian <span class="hlt">sediment</span> flux was examined in the Skeleton Coast, Namibia. Measurements of wind velocity (using sonic anemometers) and sand <span class="hlt">transport</span> (using grain impact sensors) at a sampling frequency of 10 Hz were made across a flat surface and along transects on a 9 m high barchan dune. Mean wind parameters and mass sand flux were measured using cup anemometers and wedge-shaped sand traps respectively. Vertical profile data from the sonic anemometers were used to compute turbulence and turbulent stress (Reynolds stress; instantaneous horizontal and vertical fluctuations; coherent flow structures) and their relationship with respect to sand <span class="hlt">transport</span> and evolving dune morphology. On the flat surface time-averaged parameters generally fail to characterise sand <span class="hlt">transport</span> dynamics, particularly as the averaging interval is reduced. However, horizontal wind speed correlates well with sand <span class="hlt">transport</span> even with short averaging times. Quadrant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA541799','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA541799"><span><span class="hlt">Transport</span> of Gas and Solutes in Permeable Estuarine <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2010-09-30</p> <p>inhabited by microphytobenthos and seagrass . 2) To quantify the size range and composition of the gas bubbles in the <span class="hlt">sediment</span> and the overlying water...characteristics of bubble ebullition in a shallow coastal environment with strong benthic photosynthesis (May 26-28). The goal was to determine the spatial and...each 50 μL air injection. Detection of small bubbles produced by benthic photosynthesis The goal was to assess whether the small bubbles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70000275','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70000275"><span>Estuarine <span class="hlt">sediment</span> <span class="hlt">transport</span> by gravity-driven movement of the nepheloid layer, Long Island Sound</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Poppe, L.J.; McMullen, K.Y.; Williams, S.J.; Crocker, J.M.; Doran, E.F.</p> <p>2008-01-01</p> <p>Interpretation of sidescan-sonar imagery provides evidence that down-slope gravity-driven movement of the nepheloid layer constitutes an important mode of <span class="hlt">transporting</span> <span class="hlt">sediment</span> into the basins of north-central Long Island Sound, a major US East Coast estuary. In the Western Basin, this <span class="hlt">transport</span> mechanism has formed dendritic drainage systems characterized by branching patterns of low backscatter on the seafloor that exceed 7.4 km in length and progressively widen down-slope, reaching widths of over 0.6 km at their southern distal ends. Although much smaller, dendritic patterns of similar morphology are also present in the northwestern part of the Central Basin. Because many contaminants display affinities for adsorption onto fine-grained <span class="hlt">sediments</span>, and because the Sound is affected by seasonal hypoxia, mechanisms and dispersal pathways by which inorganic and organic <span class="hlt">sediments</span> are remobilized and <span class="hlt">transported</span> impact the eventual fate of the contaminants and environmental health of the estuary. </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2014/5019/pdf/sir2014-5019.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2014/5019/pdf/sir2014-5019.pdf"><span>Remediation scenarios for attenuating peak flows and reducing <span class="hlt">sediment</span> <span class="hlt">transport</span> in Fountain Creek, Colorado, 2013</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kohn, Michael S.; Fulton, John W.; Williams, Cory A.; Stogner, Sr., Robert W.</p> <p>2014-01-01</p> <p>The U.S. Geological Survey (USGS) in cooperation with the Fountain Creek Watershed, Flood Control and Greenway District assessed remediation scenarios to attenuate peak flows and reduce <span class="hlt">sediment</span> loads in the Fountain Creek watershed. To evaluate these strategies, the U.S. Army Corps of Engineers Hydrologic Engineering Center (HEC) hydrologic and hydraulic models were employed. The U.S. Army Corps of Engineers modeling system HEC-HMS (Hydrologic Modeling System) version 3.5 was used to simulate runoff in the Fountain Creek watershed, Colorado, associated with storms of varying magnitude and duration. Rain-gage precipitation data and radar-based precipitation data from the April 28–30, 1999, and September 14–15, 2011, storm events were used in the calibration process for the HEC-HMS model. The curve number and lag time for each subwatershed and Manning's roughness coefficients for each channel reach were adjusted within an acceptable range so that the simulated and measured streamflow hydrographs for each of the 12 USGS streamgages approximated each other. The U.S. Army Corps of Engineers modeling system HEC-RAS (River Analysis System) versions 4.1 and 4.2 were used to simulate streamflow and <span class="hlt">sediment</span> <span class="hlt">transport</span>, respectively, for the Fountain Creek watershed generated by a particular storm event. Data from 15 USGS streamgages were used for model calibration and 7 of those USGS streamgages were used for model validation. The calibration process consisted of comparing the simulated water-surface elevations and the cross-section-averaged velocities from the model with those surveyed in the field at the cross section at the corresponding 15 and 7 streamgages, respectively. The final Manning’s roughness coefficients were adjusted between –30 and 30 percent at the 15 calibration streamgages from the original left, right, and channel-averaged Manning's roughness coefficients upon completion of calibration. The U.S. Army Corps of Engineers modeling system HEC</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP21E1896C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP21E1896C"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> over a Dredge Pit, Sandy Point Southeast, west flank of the Mississippi River during Summer Upcoast Currents: a Coupled Wave, Current and <span class="hlt">Sediment</span> Numerical Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaichitehrani, N.; Li, C.; Xu, K.; Bentley, S. J.; Miner, M. D.</p> <p>2017-12-01</p> <p>Sandy Point southeast, an elongated sand resource, was dredged in November 2012 to restore Pelican Island, Louisiana. Hydrodynamics and wave propagation patterns along with fluvial <span class="hlt">sediments</span> from the Mississippi River influence the <span class="hlt">sediment</span> and bottom boundary layer dynamics over Sandy Point. A state-of-the-art numerical model, Delft3D, was implemented to investigate current variations and wave transformation on Sandy Point as well as <span class="hlt">sediment</span> <span class="hlt">transport</span> pattern. Delft3d FLOW and WAVE modules were coupled and validated using WAVCIS and NDBC data. <span class="hlt">Sediment</span> <span class="hlt">transport</span> model was run by introducing both bed and river <span class="hlt">sediments</span>, consisted of mainly mud and a small fraction of sand. A <span class="hlt">sediment</span> <span class="hlt">transport</span> model was evaluated for surface <span class="hlt">sediment</span> concentration using data derived from satellite images. The model results were used to study <span class="hlt">sediment</span> dynamics and bottom boundary layer characteristics focused on the Sandy Point area during summer. Two contrasting bathymetric configurations, with and without the Sandy Point dredge pit, were used to conduct an experiment on the <span class="hlt">sediment</span> and bottom boundary layer dynamics. Preliminary model results showed that the presence of the Sandy Point pit has very limited effect on the hydrodynamics and wave pattern at the pit location. <span class="hlt">Sediments</span> from the Mississippi River outlets, especially in the vicinity of the pit, get trapped in the pit under the easterly to the northeasterly upcoast current which prevails in August. We also examined the wave-induced <span class="hlt">sediment</span> reworking and river-borne fluvial <span class="hlt">sediment</span> over Sandy Point. The effect of wind induced orbital velocity increases the bottom shear stress compared to the time with no waves, relatively small wave heights (lower than 1.5 meters) along the deepest part of the pit (about 20 meters) causes little bottom <span class="hlt">sediment</span> rework during this period. The results showed that in the summertime, river water is more likely the source of <span class="hlt">sedimentation</span> in the pit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4823E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4823E"><span>A bilayer model for bedload <span class="hlt">sediment</span> <span class="hlt">transport</span> as generalization of Exner models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Escalante, Cipriano; Fernandez-Nieto, Enrique; Morales de Luna, Tomas; Narbona Reina, Gladys</p> <p>2017-04-01</p> <p><span class="hlt">Sediment</span> can be <span class="hlt">transported</span> in several ways by the action of a river. During low <span class="hlt">transport</span> stages, particles move by sliding and rolling over the surface of the bed. This type of <span class="hlt">transport</span> is usually called bedload <span class="hlt">transport</span>. The usual approach to model these phenomena is to use the Saint-Venant-Exner model (SVE) which consists in a shallow water model coupled with a morphodynamical component for the bedload <span class="hlt">transport</span>. The bedload <span class="hlt">transport</span> depends on an empirical flux. Nevertheless, this approach presents some drawbacks, for instance, gravitational effects for bedload <span class="hlt">transport</span> is neglected and the momentum equation for the <span class="hlt">sediment</span> is missing. In this work we present a two-layer shallow water type model in order to better describe bedload <span class="hlt">transport</span>. We consider an upper layer consisting in clear water and a lower layer which accounts for the <span class="hlt">sediment</span> material. This allows to better describe the phenomena. The key point is the definition of the friction laws between the two layers. The model is a generalization of classic models as it allows to recover SVE system when the ratio between the hydrodynamic and morphodynamic time scales is small, as commonly done to derive SVE models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H53C1081G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H53C1081G"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Processes During Flood Events in the Middle LoireGauging and First Results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gautier, J.; Rodrigues, S.; Juge, P.; Peters, J.</p> <p>2008-12-01</p> <p>A hydraulic and <span class="hlt">sediment</span> <span class="hlt">transport</span> survey campaign was organised in March 2007 on the Loire River, at the Bréhémont site. The aim was to collect data useful for the understanding of fluviomorphological mechanisms. A survey procedure, established at the end of the 1960's and relying on a follow-up bathymetric surveys and ancient <span class="hlt">sediments</span> samplers was combined with modern technologies such as DGPS satellite positioning and ADCP flow gauging. The survey campaign allowed quantifying the <span class="hlt">sediment</span> <span class="hlt">transport</span> rates of the size fractions larger than 50 microns. The results confirm the earlier made hypothesis concerning the existence of a <span class="hlt">sediment</span> load moving close to the bottom and distinct from the suspended load as described in the theories. This load was called "morphological" and is composed of solids having sizes between those of the river bed and those moving in suspension at higher elevations. This statement, made on the basis of surveys on other large streams in Africa, Asia and the America's questions the concepts on which have been based the majority of the <span class="hlt">sediment</span> <span class="hlt">transport</span> theories. The analysis shows also that the rate of bedload <span class="hlt">transport</span> can be very high up to 60% in some verticals and nearly 50% on all a profil, that is much more than the rate usually admits. The present surveys show that campaigns as these are necessary in order to comprehend the processes, a condition prior to investigating solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H43D0997G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H43D0997G"><span><span class="hlt">Sediment</span> and solute <span class="hlt">transport</span> in a mountainous watershed in Valle del Cauca, Colombia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guzman, C. D.; Castro, A.; Morales, A.; Hoyos, F.; Moreno, P.; Steenhuis, T. S.</p> <p>2014-12-01</p> <p>A main goal of this study was to improve prediction of <span class="hlt">sediment</span> and solute <span class="hlt">transport</span> using soil surface and soil nutrient changes, based on field measurements, within small watersheds receiving conservation measures. <span class="hlt">Sediment</span> samples and solute concentrations were measured from two streams in the southwestern region of the Colombian Andes. Two modeling approaches for stream discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> predicted were used with one of these being used for nutrient <span class="hlt">transport</span> prediction. These streams are a part of a recent initiative from a water fund established by Asobolo, Asocaña, and Cenicaña in collaboration with the Natural Capital Project to improve conservation efforts and monitor their effects. On-site soil depth changes, groundwater depth measurements, and soil nutrient concentrations were also monitored to provide more information about changes within this mountainous watershed during one part of the yearly rainy season. This information is being coupled closely with the outlet <span class="hlt">sediment</span> concentration and solute concentration patterns to discern correlations. Lateral transects in the upper, middle, and lower part of the hillsides in the Aguaclara watershed of the Rio Bolo watershed network showed differences in soil nutrient status and soil surface depth changes. The model based on semi-distributed hydrology was able to reproduce discharge and <span class="hlt">sediment</span> <span class="hlt">transport</span> rates as well as the initially used model indicating available options for comparison of conservation changes in the future.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP43C1898H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP43C1898H"><span>An Eulerian two-phase flow model for <span class="hlt">sediment</span> <span class="hlt">transport</span> under realistic surface waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, T. J.; Kim, Y.; Cheng, Z.; Chauchat, J.</p> <p>2017-12-01</p> <p>Wave-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> is of major importance in driving beach morphology. However, the complex mechanisms associated with unsteadiness, free-surface effects, and wave-breaking turbulence have not been fully understood. Particularly, most existing models for <span class="hlt">sediment</span> <span class="hlt">transport</span> adopt bottom boundary layer approximation that mimics the flow condition in oscillating water tunnel (U-tube). However, it is well-known that there are key differences in <span class="hlt">sediment</span> <span class="hlt">transport</span> when comparing to large wave flume datasets, although the number of wave flume experiments are relatively limited regardless of its importance. Thus, a numerical model which can resolve the entire water column from the bottom boundary layer to the free surface can be a powerful tool. This study reports an on-going effort to better understand and quantify <span class="hlt">sediment</span> <span class="hlt">transport</span> under shoaling and breaking surface waves through the creation of open-source numerical models in the OpenFOAM framework. An Eulerian two-phase flow model, SedFoam (Cheng et al., 2017, Coastal Eng.) is fully coupled with a volume-of-fluid solver, interFoam/waves2Foam (Jacobsen et al., 2011, Int. J. Num. Fluid). The fully coupled model, named SedWaveFoam, regards the air and water phases as two immiscible fluids with the interfaces evolution resolved, and the <span class="hlt">sediment</span> particles as dispersed phase. We carried out model-data comparisons with the large wave flume sheet flow data for nonbreaking waves reported by Dohmen-Janssen and Hanes (2002, J. Geophysical Res.) and good agreements were obtained for <span class="hlt">sediment</span> concentration and net <span class="hlt">transport</span> rate. By further simulating a case without free-surface (mimic U-tube condition), the effects of free-surface, most notably the boundary layer streaming effect on total <span class="hlt">transport</span>, can be quantified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS21B1715M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS21B1715M"><span>Diffusive smoothing of surfzone bathymetry by gravity-driven <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moulton, M. R.; Elgar, S.; Raubenheimer, B.</p> <p>2012-12-01</p> <p>Gravity-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> often is assumed to have a small effect on the evolution of nearshore morphology. Here, it is shown that down-slope gravity-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> is an important process acting to smooth steep bathymetric features in the surfzone. Gravity-driven <span class="hlt">transport</span> can be modeled as a diffusive term in the <span class="hlt">sediment</span> continuity equation governing temporal (t) changes in bed level (h): ∂h/∂t ≈ κ ▽2h, where κ is a <span class="hlt">sediment</span> diffusion coefficient that is a function of the bed shear stress (τb) and <span class="hlt">sediment</span> properties, such as the grain size and the angle of repose. Field observations of waves, currents, and the evolution of large excavated holes (initially 10-m wide and 2-m deep, with sides as steep as 35°) in an energetic surfzone are consistent with diffusive smoothing by gravity. Specifically, comparisons of κ estimated from the measured bed evolution with those estimated with numerical model results for several <span class="hlt">transport</span> theories suggest that gravity-driven <span class="hlt">sediment</span> <span class="hlt">transport</span> dominates the bed evolution, with κ proportional to a power of τb. The models are initiated with observed bathymetry and forced with observed waves and currents. The diffusion coefficients from the measurements and from the model simulations were on average of order 10-5 m2/s, implying evolution time scales of days for features with length scales of 10 m. The dependence of κ on τb varies for different <span class="hlt">transport</span> theories and for high and low shear stress regimes. The US Army Corps of Engineers Field Research Facility, Duck, NC provided excellent logistical support. Funded by a National Security Science and Engineering Faculty Fellowship, a National Defense Science and Engineering Graduate Fellowship, and the Office of Naval Research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.3547V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.3547V"><span>Scale and processes dominating soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span>: case studies from Indonesia and Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Dijk, A. I. J. M.; Bruijnzeel, L. A.</p> <p>2009-04-01</p> <p>Soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> at different scales of space and time are dominated by a variable set of landscape properties and processes. Research results from West Java (Indonesia) and southeast Australia are presented, taking a natural resources management perspective. The dominant role of vegetation and soil health, rainfall infiltration, and connectivity between hillslope and stream are elaborated on. In humid volcanic upland West Java, vegetative cover and associated infiltration capacity are the dominant control on surface runoff and <span class="hlt">sediment</span> generation, with additional variation attributed to slope and soil surface structure. Use of process models to replicate and upscale field measurements highlighted that a predictive theory to link vegetative cover and infiltration capacity is lacking, and that full knowledge of the covariance between terrain attributes that promote <span class="hlt">sediment</span> generation is needed for process based modelling. At the hillslope to catchment scale, slope gradient and a less erodible substrate became additional constraints on <span class="hlt">sediment</span> yield. A conceptual framework relating processes, scale and <span class="hlt">sediment</span> delivery ratio was developed. In water-limited southeast Australia, measures to reduce erosion and <span class="hlt">sediment</span> production generally aim to intercept surface runoff, allowing runoff to infiltrate and <span class="hlt">sediment</span> to settle on vegetated buffer strips or roadsides or in leaky dams. It is illustrated how remote sensing can help to assess the sources of <span class="hlt">sediment</span> and hydrological connectivity at different scales and to identify opportunities for mitigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6046B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6046B"><span>Shelfal <span class="hlt">sediment</span> <span class="hlt">transport</span> by undercurrents forces turbidity current activity during high sea level, Chile continental margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bernhardt, Anne; Hebbeln, Dierk; Regenberg, Marcus; Lückge, Andreas; Strecker, Manfred. R.</p> <p>2016-04-01</p> <p>Understanding the links between terrigenous <span class="hlt">sediment</span> supply and marine <span class="hlt">transport</span> and depositional processes along tectonically active margins is essential to decipher turbidite successions as potential archives of climatic and seismic forcings and to comprehend timing and quantity of marine clastic deposition. Sequence stratigraphic models predict coarse-grained terrigenous <span class="hlt">sediment</span> delivery to deep-marine sites mainly during sea-level fall and lowstand. Marine clastic deposition during periods of transgression and highstand has been attributed to the continued geomorphic connectivity between terrestrial <span class="hlt">sediment</span> sources and marine sinks (e.g., rivers connected to submarine canyons) often facilitated by narrow shelves, high <span class="hlt">sediment</span> supply causing delta migration to the shelf edge, and/or abrupt increases in <span class="hlt">sediment</span> supply due to climatic variability or catastrophic events. To decipher the controls on Holocene highstand turbidite deposition, we analyzed twelve <span class="hlt">sediment</span> cores of spatially disparate, coeval Holocene turbidite systems along the Chile margin (29-40°S) with changing climatic and geomorphic characteristics but uniform changes of sea level. Intraslope basins in north-central Chile (29-33°S) offshore a narrow to absent shelf record a shut-off of turbidite activity during the Holocene. In contrast, core sites in south-central Chile (36-40°S) offshore a wide continental shelf have repeatedly experienced turbidite deposition during sea-level highstand conditions, even though most of the depocenters are not connected via canyons to <span class="hlt">sediment</span> sources. The interplay of stable high <span class="hlt">sediment</span> supply related to strong onshore precipitation in combination with a wide shelf, over which undercurrents move <span class="hlt">sediment</span> towards the shelf edge, appears to control Holocene turbidite <span class="hlt">sedimentation</span> and <span class="hlt">sediment</span> export to the deep sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1995/4236/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1995/4236/report.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and deposition in Lakes Marion and Moultrie, South Carolina, 1942-85</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Patterson, G.G.; Cooney, T.W.; Harvey, R.M.</p> <p>1996-01-01</p> <p>Lakes Marion and Moultrie, two large reservoirs in the South Carolina Coastal Plain, receive large inflows of <span class="hlt">sediment</span> from the Santee River. The average rate of <span class="hlt">sediment</span> deposition for both lakes during the period 1942-85 was about 0.06 inch per year, or about 800 acre-feet per year. The rate during 1983-85 was about 0.037 inch per year, or about 490 acre-feet per year, reflecting the decreasing trend in <span class="hlt">sediment</span> inflow. This is a reversal of a trend toward increasing suspended- <span class="hlt">sediment</span> concentrations in streams that were caused by farming practices in the southern Piedmont from about 1800 to about 1920. Only a small part of the eroded <span class="hlt">sediment</span> has been carried out of the Piedmont, but the remaining <span class="hlt">sediment</span> is becoming less available for <span class="hlt">transport</span>. <span class="hlt">Sediment</span> deposition is concentrated in several areas of upper Lake Marion where the velocity of the incoming water decreases significantly. Beds of aquatic macrophytes appear to encourage deposition which, in turn, creates favorable habitat for the plants. The rate of <span class="hlt">sediment</span> accumulation in Lakes Marion and Moultrie averaged 650,000 tons per year during 1983-85, reflecting a trap efficiency of 79 percent of the total <span class="hlt">sediment</span> inflow of 825,000 tons per year. Thickness of post-impoundment <span class="hlt">sediment</span> varies from about 11 feet near the mouth of the Santee River in Lake Marion to 0 feet in Lake Moultrie near Bonneau. <span class="hlt">Sediments</span> in Lake Marion tend to have finer texture and higher contents of organic matter, nutrients, and trace metals than those in Lake Moultrie.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMOS23C1323M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMOS23C1323M"><span><span class="hlt">Sediment</span> Resuspension and <span class="hlt">Transport</span> During Bora in the Western Adriatic Coastal Current</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mullenbach, B. L.; Geyer, W. R.; Sherwood, C. R.</p> <p>2004-12-01</p> <p>The Western Adriatic Coastal Current (WACC) is an important agent for along-shelf <span class="hlt">transport</span> of <span class="hlt">sediment</span> and fresh water in the western Adriatic Sea. The WACC is driven by a combination of buoyancy forcing from the Po River (northern Adriatic) and wind forcing from northeasterly Bora winds. The large seasonal pulse of freshwater (during the winter) from the Po River influences WACC strength; however, preliminary results from current measurements and model runs indicate that the WACC responds quickly and strongly to Bora wind events, with a strengthening of the current moving southward. Along-margin <span class="hlt">sediment</span> <span class="hlt">transport</span> to the south is significantly increased as a result of Bora wind events, presumably because of enhanced wave resuspension and WACC velocity. Elevated <span class="hlt">sediment</span> fluxes have been observed in both the upper water column (i.e., core of the WACC) and bottom boundary layer (BBL) during these events, which suggests that wind-driven currents may be coupled with the near-bottom <span class="hlt">transport</span>. This study addresses the interaction of the WACC with the BBL and the impact of this interaction on <span class="hlt">sediment</span> <span class="hlt">transport</span> in the western Adriatic. Two benthic tripods were deployed from November 2002 to June 2003 on an across-shelf transect near the Chienti River (at 10 and 20-m water depth), in the region where WACC begins to intensify (200 km south of Po River). Continuous measurements of suspended <span class="hlt">sediment</span> concentration and current velocity were recorded in the upper-water column and BBL to document <span class="hlt">sediment</span> <span class="hlt">transport</span> events. A time series of <span class="hlt">sediment</span> fluxes and shear velocities (from currents only, u*c; from waves and currents, u*wc) were calculated from these data. Results show that suspended <span class="hlt">sediment</span> concentrations near the seabed (few cmab) during Bora wind events are strongly correlated with u*wc, which supports a previous hypothesis that wave resuspension (rather than direct fluvial input) is responsible for much of the suspended <span class="hlt">sediment</span> available for <span class="hlt">transport</span> southward</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2009/5001/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2009/5001/"><span><span class="hlt">Transport</span> and Sources of Suspended <span class="hlt">Sediment</span> in the Mill Creek Watershed, Johnson County, Northeast Kansas, 2006-07</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lee, Casey J.; Rasmussen, Patrick P.; Ziegler, Andrew C.; Fuller, Christopher C.</p> <p>2009-01-01</p> <p>The U.S. Geological Survey, in cooperation with the Johnson County Stormwater Management Program, evaluated suspended-<span class="hlt">sediment</span> <span class="hlt">transport</span> and sources in the urbanizing, 57.4 mi2 Mill Creek watershed from February 2006 through June 2007. <span class="hlt">Sediment</span> <span class="hlt">transport</span> and sources were assessed spatially by continuous monitoring of streamflow and turbidity as well as sampling of suspended <span class="hlt">sediment</span> at nine sites in the watershed. Within Mill Creek subwatersheds (2.8-16.9 mi2), <span class="hlt">sediment</span> loads at sites downstream from increased construction activity were substantially larger (per unit area) than those at sites downstream from mature urban areas or less-developed watersheds. <span class="hlt">Sediment</span> <span class="hlt">transport</span> downstream from construction sites primarily was limited by <span class="hlt">transport</span> capacity (streamflow), whereas availability of <span class="hlt">sediment</span> supplies primarily influenced <span class="hlt">transport</span> downstream from mature urban areas. Downstream sampling sites typically had smaller <span class="hlt">sediment</span> loads (per unit area) than headwater sites, likely because of <span class="hlt">sediment</span> deposition in larger, less sloping stream channels. Among similarly sized storms, those with increased precipitation intensity <span class="hlt">transported</span> more <span class="hlt">sediment</span> at eight of the nine monitoring sites. Storms following periods of increased <span class="hlt">sediment</span> loading <span class="hlt">transported</span> less <span class="hlt">sediment</span> at two of the nine monitoring sites. In addition to monitoring performed in the Mill Creek watershed, <span class="hlt">sediment</span> loads were computed for the four other largest watersheds (48.6-65.7 mi2) in Johnson County (Blue River, Cedar, Indian, and Kill Creeks) during the study period. In contrast with results from smaller watersheds in Mill Creek, <span class="hlt">sediment</span> load (per unit area) from the most urbanized watershed in Johnson County (Indian Creek) was more than double that of other large watersheds. Potential sources of this <span class="hlt">sediment</span> include legacy <span class="hlt">sediment</span> from earlier urban construction, accelerated stream-channel erosion, or erosion from specific construction sites, such as stream-channel disturbance during bridge</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Geomo.303..299C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Geomo.303..299C"><span>The relative contribution of near-bed vs. intragravel horizontal <span class="hlt">transport</span> to fine <span class="hlt">sediment</span> accumulation processes in river gravel beds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Casas-Mulet, Roser; Lakhanpal, Garima; Stewardson, Michael J.</p> <p>2018-02-01</p> <p>Understanding flow-<span class="hlt">sediment</span> interactions is important for comprehending river functioning. Fine <span class="hlt">sediment</span> accumulation processes, in particular, have key implications for ecosystem health. However, the amount of fines generated by intragravel flows and later accumulated in gravel streambeds may have been underestimated, as the hydraulic-related driving <span class="hlt">transport</span> mechanisms in play are not clearly identified. Specifically, the relative contribution of fines from upper vs. lower <span class="hlt">sediment</span> layers in gravel beds is not well understood. By recreating flooded and dewatered conditions in an experimental flume filled with natural <span class="hlt">sediment</span>, we estimated such contributions by observing and collecting intragravel <span class="hlt">transported</span> fines that were later accumulated into a void in the middle of the <span class="hlt">sediment</span> matrix. Near-bed <span class="hlt">transport</span> in the upper <span class="hlt">sediment</span> layers (named Brinkman load) during flooded conditions accounted for most (90%) of the accumulated fines. Intragravel <span class="hlt">transport</span> in the lower <span class="hlt">sediment</span> layers (named Interstitial load) was the sole source of <span class="hlt">transport</span> and accumulation during dewatered conditions with steeper hydraulic gradients. Interstitial load accounted for 10% of the total <span class="hlt">transport</span> during flooded conditions. Although small, such estimations demonstrate that hydraulic-gradient <span class="hlt">transport</span> in the lower <span class="hlt">sediment</span> layers occurs in spite of the contradicting analytical assessments. We provide a case study to challenge the traditional approaches of assessing intragravel <span class="hlt">transport</span>, and a useful framework to understand the origin and relative contribution of fine <span class="hlt">sediment</span> accumulation in gravel beds. Such knowledge will be highly useful for the design of monitoring programs aiding river management, particularly in regulated rivers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP21E1886Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP21E1886Z"><span>Near-bed observations of high-concentration <span class="hlt">sediment</span> <span class="hlt">transport</span> in the Changjiang Estuary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Z.; Ge, J.; Ding, P.</p> <p>2017-12-01</p> <p>The North Passage, the core of turbidity maximum in the Changjiang Estuary, is now under the strong <span class="hlt">sedimentation</span> due to the abundant <span class="hlt">sediment</span> supply from the upstream Changjiang River and the river-tide interacted dynamics. Recent studies suggested that strong siltation could be attributed to bottom high-concentration <span class="hlt">sediment</span> <span class="hlt">transport</span>, which however is very difficult to be detected and observed by vessel-anchored survey methods. To better understand the mechanisms of <span class="hlt">sediment</span> <span class="hlt">transport</span> and deposition in the channel region of the North Passage and its adjacent areas, we conducted continuous field observations which covered spring and neap tide period in the wintertime of 2016, the summertime of 2015 and 2017, focusing on near-bottom <span class="hlt">sediment</span> <span class="hlt">transport</span>. Tripods mounted with multiple instruments, including up-looking and down-looking Acoustic Doppler Current Profilers(ADCP), Vector Current Meter(ADV), Optical Backscatter Sensor(OBS), ASM, ALEC and RBR were used to observe the near-bottom physical process and its induced <span class="hlt">sediment</span> dynamics. Results of these observations clearly described the current-wave-<span class="hlt">sediment</span> interaction, which produced different patterns of bottom mud suspension at different tripods. Both hydrodynamic features and suspended <span class="hlt">sediment</span> showed variations between spring and neap tide. Taking data of 2016 as an example, averaged suspended <span class="hlt">sediment</span> concentration(SSC) at two tripods was 1.52 g/L and 2.13 g/L during the neap tide, 4.51 g/L and 5.75 g/L with the peak value reaching 25 g/L during the spring tide. At the tripod which was closer to the channel region, three peaks of SSC during the spring tide occurred near the flood slack with notable salinity increase, indicating the impact of saltwater intrusion on the bottom hydrodynamics. The results showed the occurrence of high-concentration suspended <span class="hlt">sediment</span> was probably related to combined effects of bottom salinity intrusion, turbulent kinetic energy(TKE) and local stratification due to density</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Geomo.188...96G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Geomo.188...96G"><span>Channel morphology and <span class="hlt">bed-load</span> yield in fluvial, formerly-glaciated headwater streams of the Columbia Mountains, Canada</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Green, K. C.; Brardinoni, F.; Alila, Y.</p> <p>2013-04-01</p> <p>This study examines channel-reach morphology and bedload yield dynamics in relation to landscape structure and snowmelt hydrology in headwater streams of the Columbia Mountains, Canada. Data collection relies on field surveys and geographic information systems analysis in conjunction with a nested monitoring network of water discharge and bedload transfer. The landscape is characterized by subdued, formerly-glaciated upland topography in which the geomorphic significance of landslides and debris flows is negligible and fluvial processes prevail. While the spatial organization of channel morphology is chiefly controlled by glacially imposed local slope in conjunction with wood abundance and availability of glacigenic deposits, downstream patterns of the coarse grain-size fraction, bankfull width, bankfull depth, and stream power are all insensitive to systematic changes of local slope along the typically stepped long profiles. This is an indication that these alluvial systems have adjusted to the contemporary snowmelt-driven water and <span class="hlt">sediment</span> <span class="hlt">transport</span> regimes, and as such are able to compensate for the glacially-imposed boundary conditions. Bedload specific yield increases with drainage area suggesting that fluvial re-mobilization of glacial and paraglacial deposits dominate the sedimentary dynamics of basins as small as 2 km2. Stepwise multiple regression analysis shows that annual rates of <span class="hlt">sediment</span> transfer are mainly controlled by the number of peak events over threshold discharge. During such events, repeated destabilization of channel bed armoring and re-mobilization of <span class="hlt">sediment</span> temporarily stored behind LWD structures can generate bedload <span class="hlt">transport</span> across the entire snowmelt season. In particular, channel morphology controls the variability of bedload response to hydrologic forcing. In the present case studies, we show that the observed spatial variability in annual bedload yield appears to be modulated by inter-basin differences in morphometric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wsp/1669b/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wsp/1669b/report.pdf"><span><span class="hlt">Sediment</span> characteristics of small streams in southern Wisconsin, 1954-59</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Collier, Charles R.</p> <p>1963-01-01</p> <p>The results of investigations of the <span class="hlt">sediment</span> and water discharge characteristics of Black Earth Creek, Mount Vernon Creek, and Yellowstone River from 1954 to 1959 and Dell Creek for 1958 and 1959 indicate large differences in annual runoff and <span class="hlt">sediment</span> yields. The suspended-<span class="hlt">sediment</span> discharge of Black Earth Creek averaged 3,260 tons per year or 71 tons per square mile : the annual yields ranged from 27 to 102 tons per square mile. The annual suspended-<span class="hlt">sediment</span> yield of Mount Vernon Creek ranged from 48 to 171 tons per square mile and averaged 96 tons per square mile. The maximum daily discharge was 1,120 tons on April 1, 1960, during a storm which produced 67 percent of the suspended load for that water year and exceeded the discharge for the preceding 3 years. The <span class="hlt">sediment</span> discharge of the Yellowstone River averaged 6,870 tons per year or 236 tons per square riffle. The maximum daily <span class="hlt">sediment</span> discharge, 3,750 tons on April 1, 1959, occurred during a 14-day period of high flow during which the <span class="hlt">sediment</span> discharge was 15,480 tons. In 1958 and 1959, Dell Creek had suspended-<span class="hlt">sediment</span> yields of 4.7 and 26 tons per square mile of drainage area. The suspended <span class="hlt">sediment</span> <span class="hlt">transported</span> by Black Earth and Mount Vernon Creeks is about two-thirds clay and one-third silt. For Yellowstone River the particle-size distribution of the suspended <span class="hlt">sediment</span> ranged from three-fourths clay and one-fourth silt during periods of low <span class="hlt">sediment</span> discharge to one-third clay and two-thirds silt during high <span class="hlt">sediment</span> discharges. For Dell Creek nearly all of the suspended <span class="hlt">sediment</span> is clay, but the <span class="hlt">bed</span> <span class="hlt">load</span> is sand. The mean <span class="hlt">sediment</span> concentration of storm runoff averaged two to three times more in the summer than in the winter. No significant changes with time occurred in the relation between storm runoff and <span class="hlt">sediment</span> yield.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3995P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3995P"><span>The rheology of non-suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> mediated by a Newtonian fluid</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pähtz, Thomas; Durán, Orencio</p> <p>2017-04-01</p> <p>Using a coupled DEM/RANS numerical model of non-suspended <span class="hlt">sediment</span> <span class="hlt">transport</span> in a Newtonian fluid (Durán et al., POF 103306, 2012), we find that the gas-like part of the granular <span class="hlt">transport</span> flow can be described by a universal condition that constrains the average geometry of interparticle collisions. We show that this condition corresponds to a constant sliding friction coefficient μ at an appropriately defined bed surface, thus explaining the success of Bagnold's old idea to describe the <span class="hlt">sediment</span> <span class="hlt">transport</span> in analogy to sliding friction. We are currently exploring whether this rheology applies to gas-like granular flows in general. We further find a transition of the gas-like flow to either a solid-like flow (solid-to-gas transition), which is typical for aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> ('saltation'), or a liquid-like flow (liquid-to-gas transition), which is typical for subaqueous <span class="hlt">sediment</span> <span class="hlt">transport</span> ('bedload'). The transition occurs at about the location of maximal particle collision frequency. If there is a liquid-like flow below the transition, we find that it can be described by a μ(I) rheology, where I is the visco-intertial number, an appropriately defined average of the viscous and intertial number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP52A..02C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP52A..02C"><span>Flow regulation in the Swiss Alps: a river network modelling approach to investigate the impacts on <span class="hlt">bed</span> <span class="hlt">load</span> and grain size distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Costa, A.; Molnar, P.; Schmitt, R. J. P.</p> <p>2017-12-01</p> <p>The grain size distribution (GSD) of river bed <span class="hlt">sediment</span> results from the long term balance between <span class="hlt">transport</span> capacity and <span class="hlt">sediment</span> supply. Changes in climate and human activities may alter the spatial distribution of <span class="hlt">transport</span> capacity and <span class="hlt">sediment</span> supply along channels and hence impact local bedload <span class="hlt">transport</span> and GSD. The effects of changed flow are not easily inferable due the non-linear, threshold-based nature of the relation between discharge and <span class="hlt">sediment</span> mobilization, and the network-scale control on local <span class="hlt">sediment</span> supply. We present a network-scale model for fractional <span class="hlt">sediment</span> <span class="hlt">transport</span> to quantify the impact of hydropower (HP) operations on river network GSD. We represent the river network as a series of connected links for which we extract the geometric characteristics from satellite images and a digital elevation model. We assign surface roughness based on the channel bed GSD. Bed shear stress is estimated at link-scale under the assumptions of rectangular prismatic cross sections and normal flow. The mass balance between <span class="hlt">sediment</span> supply and <span class="hlt">transport</span> capacity, computed with the Wilcock and Crowe model, determines <span class="hlt">transport</span> rates of multiple grain size classes and the resulting GSD. We apply the model to the upper Rhone basin, a large Alpine basin in Switzerland. Since 1960s, changed flow conditions due to HP operations and <span class="hlt">sediment</span> storage behind dams have potentially altered the <span class="hlt">sediment</span> <span class="hlt">transport</span> of the basin. However, little is known on the magnitude and spatial distribution of these changes. We force the model with time series of daily discharge derived with a spatially distributed hydrological model for pre and post HP scenarios. We initialize GSD under the assumption that coarse grains (d90) are mobilized only during mean annual maximum flows, and on the basis of ratios between d90 and characteristic diameters estimated from field measurements. Results show that effects of flow regulation vary significantly in space and in time and are grain size</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GML....29..467G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GML....29..467G"><span>Wave forecasting and longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> gradients along a transgressive barrier island: Chandeleur Islands, Louisiana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Georgiou, Ioannis Y.; Schindler, Jennifer K.</p> <p>2009-12-01</p> <p>Louisiana barrier islands, such as the chain surrounding the southeast region of the state, are experiencing rapid loss of land area, shoreline erosion, and landward migration due to transgression and in-place drowning, and the landfall of several major hurricanes in the last decade. Observations of migration rates and overall impacts to these barrier islands are poorly understood since they do not respond in a traditional way, such as barrier rollover. This paper aims to verify how wave energy and potential longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> trends have influenced the recent evolution of the Chandeleur Islands, by direct comparison with recent observations of migration and erosion trends. The Chandeleur Islands are characterized by a bidirectional <span class="hlt">transport</span> system, with material moving from the central arc to the flanks. The longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> along the barrier islands was calculated after propagation and transformation of waves to breaking (generated using observed winds), and through the use of a common longshore <span class="hlt">sediment</span> <span class="hlt">transport</span> formula. Seasonal variations in wind climate produced changes in the <span class="hlt">transport</span> trends and gradients that agree with migration and rotation patterns observed for this barrier island system. Results suggest that wind dominance produces seasonal oscillations that cause an imbalance in the resulting <span class="hlt">transport</span> gradients that over time are responsible for higher rates of <span class="hlt">transport</span> in the northward direction. These results and data from other works verify the evolutionary model previously suggested, and qualitatively confirm the recent observations in asymmetric shoreline erosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP51A1635F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP51A1635F"><span>Testing the effects of in-stream <span class="hlt">sediment</span> sources and sinks on simulated watershed <span class="hlt">sediment</span> yield using the coupled U.S. Army Corps of Engineers GSSHA Model and SEDLIB <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Library</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Floyd, I. E.; Downer, C. W.; Brown, G.; Pradhan, N. R.</p> <p>2017-12-01</p> <p>The Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model is the US Army Corps of Engineers' (USACE)'s only fully coupled overland/in-stream <span class="hlt">sediment</span> <span class="hlt">transport</span> model. While the overland <span class="hlt">sediment</span> <span class="hlt">transport</span> formulation in GSSHA is considered state of the art, the existing in-stream <span class="hlt">sediment</span> <span class="hlt">transport</span> formulation is less robust. A major omission in the formulation of the existing GSSHA in-stream model is the lack of in-stream sources of fine materials. In this effort, we enhanced the in-stream <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity of GSSHA by linking GSSHA to the SEDLIB <span class="hlt">sediment</span> <span class="hlt">transport</span> library. SEDLIB was developed at the Coastal and Hydraulics Laboratory (CHL) under the System Wide Water Resources Program (SWWRP) and Flood and Coastal (F&C) research program. It is designed to provide a library of <span class="hlt">sediment</span> flux formulations for hydraulic and hydrologic models, such as GSSHA. This new version of GSSHA, with the updated in-stream <span class="hlt">sediment</span> <span class="hlt">transport</span> simulation capability afforded by the linkage to SEDLIB, was tested in against observations in an experimental watershed that had previously been used as a test bed for GSSHA. The results show a significant improvement in the ability to model in-stream sources of fine <span class="hlt">sediment</span>. This improved capability will broaden the applicability of GSSHA to larger watersheds and watersheds with complex <span class="hlt">sediment</span> dynamics, such as those subjected to fire hydrology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A33F2440W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A33F2440W"><span>Reducing uncertainty in dust monitoring to detect aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> responses to land cover change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Webb, N.; Chappell, A.; Van Zee, J.; Toledo, D.; Duniway, M.; Billings, B.; Tedela, N.</p> <p>2017-12-01</p> <p>Anthropogenic land use and land cover change (LULCC) influence global rates of wind erosion and dust emission, yet our understanding of the magnitude of the responses remains poor. Field measurements and monitoring provide essential data to resolve aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> patterns and assess the impacts of human land use and management intensity. Data collected in the field are also required for dust model calibration and testing, as models have become the primary tool for assessing LULCC-dust cycle interactions. However, there is considerable uncertainty in estimates of dust emission due to the spatial variability of <span class="hlt">sediment</span> <span class="hlt">transport</span>. Field sampling designs are currently rudimentary and considerable opportunities are available to reduce the uncertainty. Establishing the minimum detectable change is critical for measuring spatial and temporal patterns of <span class="hlt">sediment</span> <span class="hlt">transport</span>, detecting potential impacts of LULCC and land management, and for quantifying the uncertainty of dust model estimates. Here, we evaluate the effectiveness of common sampling designs (e.g., simple random sampling, systematic sampling) used to measure and monitor aeolian <span class="hlt">sediment</span> <span class="hlt">transport</span> rates. Using data from the US National Wind Erosion Research Network across diverse rangeland and cropland cover types, we demonstrate how only large changes in <span class="hlt">sediment</span> mass flux (of the order 200% to 800%) can be detected when small sample sizes are used, crude sampling designs are implemented, or when the spatial variation is large. We then show how statistical rigour and the straightforward application of a sampling design can reduce the uncertainty and detect change in <span class="hlt">sediment</span> <span class="hlt">transport</span> over time and between land use and land cover types.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70000035','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70000035"><span>Development of a three-dimensional, regional, coupled wave, current, and <span class="hlt">sediment-transport</span> model</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Warner, J.C.; Sherwood, C.R.; Signell, R.P.; Harris, C.K.; Arango, H.G.</p> <p>2008-01-01</p> <p>We are developing a three-dimensional numerical model that implements algorithms for <span class="hlt">sediment</span> <span class="hlt">transport</span> and evolution of bottom morphology in the coastal-circulation model Regional Ocean Modeling System (ROMS v3.0), and provides a two-way link between ROMS and the wave model Simulating Waves in the Nearshore (SWAN) via the Model-Coupling Toolkit. The coupled model is applicable for fluvial, estuarine, shelf, and nearshore (surfzone) environments. Three-dimensional radiation-stress terms have been included in the momentum equations, along with effects of a surface wave roller model. The <span class="hlt">sediment-transport</span> algorithms are implemented for an unlimited number of user-defined non-cohesive <span class="hlt">sediment</span> classes. Each class has attributes of grain diameter, density, settling velocity, critical stress threshold for erosion, and erodibility constant. Suspended-<span class="hlt">sediment</span> <span class="hlt">transport</span> in the water column is computed with the same advection-diffusion algorithm used for all passive tracers and an additional algorithm for vertical settling that is not limited by the CFL criterion. Erosion and deposition are based on flux formulations. A multi-level bed framework tracks the distribution of every size class in each layer and stores bulk properties including layer thickness, porosity, and mass, allowing computation of bed morphology and stratigraphy. Also tracked are bed-surface properties including active-layer thickness, ripple geometry, and bed roughness. Bedload <span class="hlt">transport</span> is calculated for mobile <span class="hlt">sediment</span> classes in the top layer. Bottom-boundary layer submodels parameterize wave-current interactions that enhance bottom stresses and thereby facilitate <span class="hlt">sediment</span> <span class="hlt">transport</span> and increase bottom drag, creating a feedback to the circulation. The model is demonstrated in a series of simple test cases and a realistic application in Massachusetts Bay. </p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2012/5269/sir12-5269.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2012/5269/sir12-5269.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> to and from small impoundments in northeast Kansas, March 2009 through September 2011</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Foster, Guy M.; Lee, Casey J.; Ziegler, Andrew C.</p> <p>2012-01-01</p> <p>The U.S. Geological Survey, in cooperation with the Kansas Water Office, investigated <span class="hlt">sediment</span> <span class="hlt">transport</span> to and from three small impoundments (average surface area of 0.1 to 0.8 square miles) in northeast Kansas during March 2009 through September 2011. Streamgages and continuous turbidity sensors were operated upstream and downstream from Atchison County, Banner Creek, and Centralia Lakes to study the effect of varied watershed characteristics and agricultural practices on <span class="hlt">sediment</span> <span class="hlt">transport</span> in small watersheds in northeast Kansas. Atchison County Lake is located in a predominantly agricultural basin of row crops, with wide riparian buffers along streams, a substantial amount of tile drainage, and numerous small impoundments (less than 0.05 square miles; hereafter referred to as “ponds”). Banner Creek Lake is a predominantly grassland basin with numerous small ponds located in the watershed, and wide riparian buffers along streams. Centralia Lake is a predominantly agricultural basin of row crops with few ponds, few riparian buffers along streams, and minimal tile drainage. Upstream from Atchison County, Banner Creek, and Centralia Lakes 24, 38, and 32 percent, respectively, of the total load was <span class="hlt">transported</span> during less than 0.1 percent (approximately 0.9 days) of the time. Despite less streamflow in 2011, larger <span class="hlt">sediment</span> loads during that year indicate that not all storm events <span class="hlt">transport</span> the same amount of <span class="hlt">sediment</span>; larger, extreme storms during the spring may <span class="hlt">transport</span> much larger <span class="hlt">sediment</span> loads in small Kansas watersheds. Annual <span class="hlt">sediment</span> yields were 360, 400, and 970 tons per square mile per year at Atchison County, Banner, and Centralia Lake watersheds, respectively, which were less than estimated yields for this area of Kansas (between 2,000 and 5,000 tons per square mile per year). Although Centralia and Atchison County Lakes had similar percentages of agricultural land use, mean annual <span class="hlt">sediment</span> yields upstream from Centralia Lake were about 2.7 times</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MS%26E..136a2072N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MS%26E..136a2072N"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> Dynamic in a Meandering Fluvial System: Case Study of Chini River</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nazir, M. H. M.; Awang, S.; Shaaban, A. J.; Yahaya, N. K. E. M.; Jusoh, A. M.; Arumugam, M. A. R. M. A.; Ghani, A. A.</p> <p>2016-07-01</p> <p><span class="hlt">Sedimentation</span> in river reduces the flood carrying capacity which lead to the increasing of inundation area in the river basin. Basic <span class="hlt">sediment</span> <span class="hlt">transport</span> can predict the fluvial processes in natural rivers and stream through modeling approaches. However, the <span class="hlt">sediment</span> <span class="hlt">transport</span> dynamic in a small meandering and low-lying fluvial system is considered scarce in Malaysia. The aim of this study was to analyze the current riverbed erosion and <span class="hlt">sedimentation</span> scenarios along the Chini River, Pekan, Pahang. The present study revealed that silt and clay has potentially been eroded several parts of the river. Sinuosity index (1.98) indicates that Chini River is very unstable and continuous erosion process in waterways has increase the riverbank instability due to the meandering factors. The riverbed erosional and depositional process in the Chini River is a sluggish process since the lake reduces the flow velocity and causes the deposited particles into the silt and clay soil at the bed of the lake. Besides, the bed layer of the lake comprised of cohesive silt and clayey composition that tend to attach the larger grain size of <span class="hlt">sediment</span>. The present study estimated the total <span class="hlt">sediment</span> accumulated along the Chini River is 1.72 ton. The HEC-RAS was employed in the simulations and in general the model performed well, once all parameters were set within their effective ranges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JHyd..411....1R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JHyd..411....1R"><span><span class="hlt">Sediments</span> as tracers for <span class="hlt">transport</span> and deposition processes in peri-alpine lakes: A case study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Righetti, Maurizio; Toffolon, Marco; Lucarelli, Corrado; Serafini, Michele</p> <p>2011-12-01</p> <p>SummaryThe benthic <span class="hlt">sediment</span> fingerprint is analysed in the small peri-alpine lake Levico (Trentino, Italy) to identify the causes of recurrent phenomena of turbidity peaks, particularly evident in a littoral region of the water body. In order to study the <span class="hlt">sediment</span> <span class="hlt">transport</span> processes, we exploit the fact that the <span class="hlt">sediment</span> supply from the major tributary has a specific chemical composition, which differs from that of the nearby lake basin. Three elements (Fe, Al, K) have been used as tracers to identify the source and the deposition patterns of tributary <span class="hlt">sediments</span>, and another typical element, Si, has been critically analysed because of its dual (allochthonous and autochthonous) origin. Several samples of the benthic material have been analysed using SEM-EDS, and the results of the sedimentological characterisation have been compared with the patterns of <span class="hlt">sediment</span> accumulation at the bed of the lake obtained using a three-dimensional numerical model, in response to the tributary supply under different external forcing and stratification conditions. The coupled use of field measurements and numerical results suggests that the turbidity phenomena are strongly related to the deposition of the <span class="hlt">sediments</span> supplied by the tributary stream, and shows that it is possible to reconstruct the process of local <span class="hlt">transport</span> when the tributary inflow is chemically specific.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13B1609K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13B1609K"><span>Numerical Simulation of Plume <span class="hlt">Transport</span> in Channel Bend with Different <span class="hlt">Sediment</span> Diameters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, H. S.; Chen, H. C.</p> <p>2017-12-01</p> <p>The flow and <span class="hlt">transport</span> of suspended <span class="hlt">sediment</span> particles, in the form of plume, were simulated using an in-house Computational Fluid Dynamics (CFD) solver FANS3D (Finite Analytic Navier-Stokes code for 3D flow). The motivation for this investigation is to provide a means to simulate and visualize dispersal systems in a complex flow environment. The physical domain considered is a 90-degrees channel bend with wingwall abutments, which induces complex, three-dimensional flow characteristics. At the inlet of the channel, a <span class="hlt">sediment</span> plume with the volumetric concentration of 1,000 parts per million (ppm) was constantly supplied. For simplicity, it was assumed that neither deposition nor erosion takes place inside the channel and settling <span class="hlt">sediment</span> was made to pass through the bed surface. The effect of the <span class="hlt">sediment</span> particle size was also analyzed using two different median diameters: 0.10 mm and 0.20 mm. It was shown that flow acceleration and vortices cause strong mixing inside the channel. The three-dimensional time series from the simulation captured increasing suspended <span class="hlt">sediment</span> concentration downstream of the abutments, along the outer bank. When the median diameter was varied, the <span class="hlt">sediment</span> concentration at certain locations differed by orders of magnitude, indicating that the settling velocity dominates the <span class="hlt">transport</span> process for larger diameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6199P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6199P"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> patterns and climate change: the downstream Tuul River case study, Northern Mongolia.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pietroń, Jan; Jarsjö, Jerker</p> <p>2014-05-01</p> <p>Ongoing changes in the Central Asian climate including increasing temperatures can influence the hydrological regimes of rivers and the waterborne <span class="hlt">transport</span> of <span class="hlt">sediments</span>. Changes in the latter, especially in combination with adverse human activities, may severely impact water quality and aquatic ecosystems. However, waterborne <span class="hlt">transport</span> of <span class="hlt">sediments</span> is a result of complex processes and varies considerably between, and even within, river systems. There is therefore a need to increase our general knowledge about <span class="hlt">sediment</span> <span class="hlt">transport</span> under changing climate conditions. The Tuul River, the case site of this study, is located in the upper part of the basin of the Selenga River that is the main tributary to Lake Baikal, a UNESCO World Heritage Site. Like many other rivers located in the steppes of Northern Mongolia, the Tuul River is characterized by a hydrological regime that is not disturbed by engineered structures such as reservoirs and dams. However, the water quality of the downstream Tuul River is increasingly affected by adverse human activities - including placer gold mining. The largest contribution to the annual river discharge occurs during the relatively warm period in May to August. Typically, there are numerous rainfall events during this period that cause considerable river flow peaks. Parallel work has furthermore shown that due to climate change, the daily variability of discharge and numbers of peak flow events in the Tuul River Basin has increased during the past 60 years. This trend is expected to continue. We here aim at increasing our understanding of future <span class="hlt">sediment</span> <span class="hlt">transport</span> patterns in the Tuul River, specifically considering the scenario that peak flow events may become more frequent due to climate change. We use a one-dimensional <span class="hlt">sediment</span> <span class="hlt">transport</span> model of the downstream reach of the river to simulate natural patterns of <span class="hlt">sediment</span> <span class="hlt">transport</span> for a recent hydrological year. In general, the results show that <span class="hlt">sediment</span> <span class="hlt">transport</span> varies considerably</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15952347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15952347"><span>Colloid-facilitated <span class="hlt">transport</span> of cesium in variably saturated Hanford <span class="hlt">sediments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Gang; Flury, Markus; Harsh, James B; Lichtner, Peter C</p> <p>2005-05-15</p> <p>Radioactive 137Cs has leaked from underground waste tanks into the vadose zone at the Hanford Reservation in south-central Washington State. There is concern that 137Cs, currently located in the vadose zone, can reach the groundwater. In this study, we investigated whether, and to what extent, colloidal particles can facilitate the <span class="hlt">transport</span> of 137Cs at Hanford. We used colloidal materials isolated from Hanford <span class="hlt">sediments</span>. <span class="hlt">Transport</span> experiments were conducted under variably saturated, steady-state flow conditions in repacked, 20 cm long Hanford <span class="hlt">sediment</span> columns, with effective water saturations ranging from 0.2 to 1.0. Cesium, pre-associated with colloids, was stripped off during <span class="hlt">transport</span> through the <span class="hlt">sediments</span>. The higher the flow rates, the less Cs was stripped off, indicating in part that Cs desorption from carrying colloids was a residence-time-dependent process. Depending on the flow rate, up to 70% of the initially sorbed Cs desorbed from colloidal carriers and was captured in the stationary <span class="hlt">sediments</span>. Less Cs was stripped off colloids under unsaturated than under saturated flow conditions at similar flow rates. This phenomenon was likely due to the reduced availability of sorption sites for Cs on the <span class="hlt">sediments</span> as the water content decreased and water flow was divided between mobile and immobile regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27166177','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27166177"><span>Control factors and scale analysis of annual river water, <span class="hlt">sediments</span> and carbon <span class="hlt">transport</span> in China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Chunlin; Wang, Genxu; Sun, Xiangyang; Chang, Ruiying; Mao, Tianxu</p> <p>2016-05-11</p> <p>Under the context of dramatic human disturbances on river system, the processes that control the <span class="hlt">transport</span> of water, <span class="hlt">sediment</span>, and carbon from river basins to coastal seas are not completely understood. Here we performed a quantitative synthesis for 121 sites across China to find control factors of annual river exports (Rc: runoff coefficient; TSSC: total suspended <span class="hlt">sediment</span> concentration; TSSL: total suspended <span class="hlt">sediment</span> loads; TOCL: total organic carbon loads) at different spatial scales. The results indicated that human activities such as dam construction and vegetation restoration might have a greater influence than climate on the <span class="hlt">transport</span> of river <span class="hlt">sediment</span> and carbon, although climate was a major driver of Rc. Multiple spatial scale analyses indicated that Rc increased from the small to medium scale by 20% and then decreased at the sizable scale by 20%. TSSC decreased from the small to sizeable scale but increase from the sizeable to large scales; however, TSSL significantly decreased from small (768 g·m(-2)·a(-1)) to medium spatial scale basins (258 g·m(-2)·a(-1)), and TOCL decreased from the medium to large scale. Our results will improve the understanding of water, <span class="hlt">sediment</span> and carbon <span class="hlt">transport</span> processes and contribute better water and land resources management strategies from different spatial scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614044M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614044M"><span>Numerical Demonstration of Massive <span class="hlt">Sediment</span> <span class="hlt">Transport</span> and Cs Recontamination by River Flooding in Fukushima Costal Area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Machida, Masahiko; Yamada, Susumu; Itakura, Mitsuhiro; Okumura, Masahiko; Kitamura, Akihiro</p> <p>2014-05-01</p> <p>Radioactive Cs recontamination brought about by deposition of silt and clay on river beds has been a central issue of environmental recovery problems in Fukushima prefecture after the Fukushima Dai-ichi nuclear power plant (FDNPP) accident. In fact, the river-side <span class="hlt">sediment</span> monitored by using remote controlled helicopters and direct sampling measurements has been confirmed to be highly contaminated compared to the other areas, which just naturally decay. Such contamination <span class="hlt">transportation</span> is especially remarkable in a few rivers in coastal areas of Fukushima prefecture, because their water and <span class="hlt">sediment</span> are supplied from the highly contaminated area along the northwest direction from FDNPPs. Thus, we numerically study the <span class="hlt">sediment</span> <span class="hlt">transportation</span> in rivers by using 2D river simulation framework named iRIC developed by Shimizu et al. Consequently, we find that flood brought about by typhoon is mainly required for the massive <span class="hlt">transport</span> and the <span class="hlt">sediment</span> deposition in the flood plain is efficiently promoted by plants naturally grown on the plain. In this presentation, we reveal when and where the <span class="hlt">sediment</span> deposition occurs in the event of floods through direct numerical simulations. We believe that the results are suggestive for the next planning issue related with decontamination in highly-contaminated evacuated districts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApWS....7.4287E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApWS....7.4287E"><span>Design of a fuzzy differential evolution algorithm to predict non-deposition <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ebtehaj, Isa; Bonakdari, Hossein</p> <p>2017-12-01</p> <p>Since the flow entering a sewer contains solid matter, deposition at the bottom of the channel is inevitable. It is difficult to understand the complex, three-dimensional mechanism of <span class="hlt">sediment</span> <span class="hlt">transport</span> in sewer pipelines. Therefore, a method to estimate the limiting velocity is necessary for optimal designs. Due to the inability of gradient-based algorithms to train Adaptive Neuro-Fuzzy Inference Systems (ANFIS) for non-deposition <span class="hlt">sediment</span> <span class="hlt">transport</span> prediction, a new hybrid ANFIS method based on a differential evolutionary algorithm (ANFIS-DE) is developed. The training and testing performance of ANFIS-DE is evaluated using a wide range of dimensionless parameters gathered from the literature. The input combination used to estimate the densimetric Froude number ( Fr) parameters includes the volumetric <span class="hlt">sediment</span> concentration ( C V ), ratio of median particle diameter to hydraulic radius ( d/R), ratio of median particle diameter to pipe diameter ( d/D) and overall friction factor of <span class="hlt">sediment</span> ( λ s ). The testing results are compared with the ANFIS model and regression-based equation results. The ANFIS-DE technique predicted <span class="hlt">sediment</span> <span class="hlt">transport</span> at limit of deposition with lower root mean square error (RMSE = 0.323) and mean absolute percentage of error (MAPE = 0.065) and higher accuracy ( R 2 = 0.965) than the ANFIS model and regression-based equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2015/5169/sir20155169.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2015/5169/sir20155169.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> and evaluation of <span class="hlt">sediment</span> surrogate ratings in the Kootenai River near Bonners Ferry, Idaho, Water Years 2011–14</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wood, Molly S.; Fosness, Ryan L.; Etheridge, Alexandra B.</p> <p>2015-12-14</p> <p>Acoustic surrogate ratings were developed between backscatter data collected using acoustic Doppler velocity meters (ADVMs) and results of suspended-<span class="hlt">sediment</span> samples. Ratings were successfully fit to various <span class="hlt">sediment</span> size classes (total, fines, and sands) using ADVMs of different frequencies (1.5 and 3 megahertz). Surrogate ratings also were developed using variations of streamflow and seasonal explanatory variables. The streamflow surrogate ratings produced average annual <span class="hlt">sediment</span> load estimates that were 8–32 percent higher, depending on site and <span class="hlt">sediment</span> type, than estimates produced using the acoustic surrogate ratings. The streamflow surrogate ratings tended to overestimate suspended-<span class="hlt">sediment</span> concentrations and loads during periods of elevated releases from Libby Dam as well as on the falling limb of the streamflow hydrograph. Estimates from the acoustic surrogate ratings more closely matched suspended-<span class="hlt">sediment</span> sample results than did estimates from the streamflow surrogate ratings during these periods as well as for rating validation samples collected in water year 2014. Acoustic surrogate technologies are an effective means to obtain continuous, accurate estimates of suspended-<span class="hlt">sediment</span> concentrations and loads for general monitoring and <span class="hlt">sediment-transport</span> modeling. In the Kootenai River, continued operation of the acoustic surrogate sites and use of the acoustic surrogate ratings to calculate continuous suspended-<span class="hlt">sediment</span> concentrations and loads will allow for tracking changes in <span class="hlt">sediment</span> <span class="hlt">transport</span> over time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813331L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813331L"><span><span class="hlt">Sediment</span> <span class="hlt">Transportation</span> Induced by Deep-Seated Landslides in a Debris Flow Basin in Taiwan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Meei Ling; Chen, Te Wei; Chen, Yong Sheng; Sin Jhuang, Han</p> <p>2016-04-01</p> <p>Typhoon Morakot brought huge amount of rainfall to the southern Taiwan in 2009 and caused severe landslides and debris flow hazard. After Typhoon Morakot, it was found that the volume of <span class="hlt">sediment</span> <span class="hlt">transported</span> by the debris flow and its effects on the affected area were much more significant compared to previous case history, which may due to the huge amount of rainfall causing significant deep-seated landslides in the basin. In this study, the effects and tendency of the <span class="hlt">sediment</span> <span class="hlt">transportation</span> in a river basin following deep-seated landslides caused by typhoon Morakot were evaluated. We used LiDAR, DEM, and aerial photo to identify characteristics of deep-seated landslides in a debris flow river basin, KSDF079 in Liuoguey District, Kaohsiung City, Taiwan. Eight deep-seated landslides were identified in the basin. To estimate the potential landslide volume associated with the deep-seated landslides, the stability analysis was conducted to locate the critical sliding surface, and the potential landside volume was estimated based on the estimation equation proposed by the International Geotechnical Societies' UNESCO Working Party on World Landslide Inventory (WP/WLI, 1990). The total potential landslide volume of the eight deep-seated landslides in KSDF079 basin was about 28,906,856 m3. Topographic analysis was performed by using DEM before and LiDAR derived DEM after typhoon Morakot to calculate the landslide volume <span class="hlt">transported</span>. The result of erosion volume and deposition volume lead to a run out volume of 5,832,433 m3. The results appeared to consist well with the field condition and aerial photo. Comparing the potential landslide volume and run out volume of eight deep-seated landslides, it was found that the remaining potential landslide volume was about 80%. Field investigation and topographic analysis of the KSDF079 debris flow revealed that a significant amount of <span class="hlt">sediment</span> deposition remained in the river channel ranging from the middle to the downstream</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13B1610L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13B1610L"><span><span class="hlt">Sediment</span> <span class="hlt">Transport</span> and Slope Stability of Ship Shoal Borrow Areas for Coastal Restoration of Louisiana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, H.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; Wilson, C.; Xue, Z.</p> <p>2017-12-01</p> <p>Sandy barrier islands along Louisiana coast are degrading rapidly due to both natural and anthropogenic factors. Ship Shoal is one of the largest offshore sand resources, and has been used as a borrow area for Caminada Headland Restoration Project. Our knowledge of <span class="hlt">sediment</span> <span class="hlt">transport</span> and infilling processes in this new sandy and dynamic borrow area is rather limited. High resolution sub-bottom seismic data, side scan sonar images, multi-beam bathymetry and laser <span class="hlt">sediment</span> grain size data were used to study seafloor morphological evolution and pit wall stability in response to both physical and geological processes. The multi-beam bathymetry and seismic profiling inside the pit showed that disequilibrium conditions led to rapid infilling in the pits at the beginning, but this process slowed down after the pit slope became stable and topography became smooth. We hypothesize that the erosion of the adjacent seabed <span class="hlt">sediment</span> by energetic waves and longshore currents, the supply of suspended <span class="hlt">sediment</span> from the rivers, and the erodible materials produced by local mass wasting on pit walls are three main types of infilling <span class="hlt">sediments</span>. Compared with mud-capped dredge pits, this sandy dredge pit seems to have more gentle slopes on pit walls, which might be controlled by the angle of repose. Infilling <span class="hlt">sediment</span> seems to be dominantly sandy, with some mud patches on bathymetric depressions. This study helps us better understand the impacts of mining <span class="hlt">sediment</span> for coastal restoration and improves sand resource management efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2013/5083/pdf/sir20135083.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2013/5083/pdf/sir20135083.pdf"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> in the lower Snake and Clearwater River Basins, Idaho and Washington, 2008–11</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Clark, Gregory M.; Fosness, Ryan L.; Wood, Molly S.</p> <p>2013-01-01</p> <p><span class="hlt">Sedimentation</span> is an ongoing maintenance problem for reservoirs, limiting reservoir storage capacity and navigation. Because Lower Granite Reservoir in Washington is the most upstream of the four U.S. Army Corps of Engineers reservoirs on the lower Snake River, it receives and retains the largest amount of <span class="hlt">sediment</span>. In 2008, in cooperation with the U.S. Army Corps of Engineers, the U.S. Geological Survey began a study to quantify <span class="hlt">sediment</span> <span class="hlt">transport</span> to Lower Granite Reservoir. Samples of suspended <span class="hlt">sediment</span> and bedload were collected from streamgaging stations on the Snake River near Anatone, Washington, and the Clearwater River at Spalding, Idaho. Both streamgages were equipped with an acoustic Doppler velocity meter to evaluate the efficacy of acoustic backscatter for estimating suspended-<span class="hlt">sediment</span> concentrations and <span class="hlt">transport</span>. In 2009, <span class="hlt">sediment</span> sampling was extended to 10 additional locations in tributary watersheds to help identify the dominant source areas for <span class="hlt">sediment</span> delivery to Lower Granite Reservoir. Suspended-<span class="hlt">sediment</span> samples were collected 9–15 times per year at each location to encompass a range of streamflow conditions and to capture significant hydrologic events such as peak snowmelt runoff and rain-on-snow. Bedload samples were collected at a subset of stations where the stream conditions were conducive for sampling, and when streamflow was sufficiently high for bedload <span class="hlt">transport</span>. At most sampling locations, the concentration of suspended <span class="hlt">sediment</span> varied by 3–5 orders of magnitude with concentrations directly correlated to streamflow. The largest median concentrations of suspended <span class="hlt">sediment</span> (100 and 94 mg/L) were in samples collected from stations on the Palouse River at Hooper, Washington, and the Salmon River at White Bird, Idaho, respectively. The smallest median concentrations were in samples collected from the Selway River near Lowell, Idaho (11 mg/L), the Lochsa River near Lowell, Idaho (11 mg/L), the Clearwater River at Orofino, Idaho (13 mg</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17544204','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17544204"><span>The mountain-lowland debate: deforestation and <span class="hlt">sediment</span> <span class="hlt">transport</span> in the upper Ganga catchment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wasson, R J; Juyal, N; Jaiswal, M; McCulloch, M; Sarin, M M; Jain, V; Srivastava, P; Singhvi, A K</p> <p>2008-07-01</p> <p>The Himalaya-Gangetic Plain region is the iconic example of the debate about the impact on lowlands of upland land-use change. Some of the scientific aspects of this debate are revisited by using new techniques to examine the role of deforestation in erosion and river <span class="hlt">sediment</span> <span class="hlt">transport</span>. The approach is whole-of-catchment, combining a history of deforestation with a history of <span class="hlt">sediment</span> sources from well before deforestation. It is shown that deforestation had some effect on one very large erosional event in 1970, in the Alaknanda subcatchment of the Upper Ganga catchment, but that both deforestation and its effects on erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> are far from uniform in the Himalaya. Large magnitude erosional events occur for purely natural reasons. The impact on the Gangetic Plain of erosion caused by natural events and land cover change remains uncertain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.6343H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.6343H"><span>Cross-shore <span class="hlt">transport</span> of nearshore <span class="hlt">sediment</span> by river plume frontal pumping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horner-Devine, Alexander R.; Pietrzak, Julie D.; Souza, Alejandro J.; McKeon, Margaret A.; Meirelles, Saulo; Henriquez, Martijn; Flores, Raúl P.; Rijnsburger, Sabine</p> <p>2017-06-01</p> <p>We present a new mechanism for cross-shore <span class="hlt">transport</span> of fine <span class="hlt">sediment</span> from the nearshore to the inner shelf resulting from the onshore propagation of river plume fronts. Onshore frontal propagation is observed in moorings and radar images, which show that fronts penetrate onshore through the nearshore and surf zone, almost to the waterline. During frontal passage a two-layer counterrotating velocity field characteristic of tidal straining is immediately set up, generating a net offshore flow beneath the plume. The seaward flow at depth carries with it high suspended <span class="hlt">sediment</span> concentrations, which appear to have been generated by wave resuspension in the nearshore region. These observations describe a mechanism by which vertical density stratification can drive exchange of material between the nearshore region and the inner shelf. To our knowledge these are the first observations of this frontal pumping mechanism, which is expected to play an important role in <span class="hlt">sediment</span> <span class="hlt">transport</span> near river mouths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70043372','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70043372"><span>Modeling of soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> in the East River Basin in southern China</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wu, Yping; Chen, Ji</p> <p>2012-01-01</p> <p>Soil erosion is a major global environmental problem that has caused many issues involving land degradation, <span class="hlt">sedimentation</span> of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical <span class="hlt">sediment</span> <span class="hlt">transport</span> method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating <span class="hlt">sediment</span> <span class="hlt">transport</span> process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low <span class="hlt">sediment</span> concentrations along the river. We also found that the East River is mainly characterized by <span class="hlt">sediment</span> deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in <span class="hlt">sediment</span> modeling for other basins worldwide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23137981','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23137981"><span>Modeling of soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> in the East River Basin in southern China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Yiping; Chen, Ji</p> <p>2012-12-15</p> <p>Soil erosion is a major global environmental problem that has caused many issues involving land degradation, <span class="hlt">sedimentation</span> of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and <span class="hlt">sediment</span> <span class="hlt">transport</span> along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical <span class="hlt">sediment</span> <span class="hlt">transport</span> method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating <span class="hlt">sediment</span> <span class="hlt">transport</span> process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low <span class="hlt">sediment</span> concentrations along the river. We also found that the East River is mainly characterized by <span class="hlt">sediment</span> deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in <span class="hlt">sediment</span> modeling for other basins worldwide. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRF..122.1090C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRF..122.1090C"><span>Interplay between spatially explicit <span class="hlt">sediment</span> sourcing, hierarchical river-network structure, and in-channel bed material <span class="hlt">sediment</span> <span class="hlt">transport</span> and storage dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Czuba, Jonathan A.; Foufoula-Georgiou, Efi; Gran, Karen B.; Belmont, Patrick; Wilcock, Peter R.</p> <p>2017-05-01</p> <p>Understanding how <span class="hlt">sediment</span> moves along source to sink pathways through watersheds—from hillslopes to channels and in and out of floodplains—is a fundamental problem in geomorphology. We contribute to advancing this understanding by modeling the <span class="hlt">transport</span> and in-channel storage dynamics of bed material <span class="hlt">sediment</span> on a river network over a 600 year time period. Specifically, we present spatiotemporal changes in bed <span class="hlt">sediment</span> thickness along an entire river network to elucidate how river networks organize and process <span class="hlt">sediment</span> supply. We apply our model to sand <span class="hlt">transport</span> in the agricultural Greater Blue Earth River Basin in Minnesota. By casting the arrival of <span class="hlt">sediment</span> to links of the network as a Poisson process, we derive analytically (under supply-limited conditions) the time-averaged probability distribution function of bed <span class="hlt">sediment</span> thickness for each link of the river network for any spatial distribution of inputs. Under <span class="hlt">transport</span>-limited conditions, the analytical assumptions of the Poisson arrival process are violated (due to in-channel storage dynamics) where we find large fluctuations and periodicity in the time series of bed <span class="hlt">sediment</span> thickness. The time series of bed <span class="hlt">sediment</span> thickness is the result of dynamics on a network in propagating, altering, and amalgamating <span class="hlt">sediment</span> inputs in sometimes unexpected ways. One key insight gleaned from the model is that there can be a small fraction of reaches with relatively low-<span class="hlt">transport</span> capacity within a nonequilibrium river network acting as "bottlenecks" that control <span class="hlt">sediment</span> to downstream reaches, whereby fluctuations in bed elevation can dissociate from signals in <span class="hlt">sediment</span> supply.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1112306B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1112306B"><span>Towards the development of a combined Norovirus and <span class="hlt">sediment</span> <span class="hlt">transport</span> model for coastal waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barry, K.; O'Kane, J. P. J.</p> <p>2009-04-01</p> <p>Sewage effluent in coastal waters used for oyster culture poses a risk to human health. The primary pathogen in outbreaks of gastroenteritis following consumption of raw oysters is the Norovirus or "winter vomiting bug". The Norovirus is a highly infectious RNA virus of the Caliciviridae taxonomic family. It has a long survival time in coastal waters (T90 = 30 days in winter). Oysters selectively concentrate Norovirus in their digestive ducts. The virus cannot be removed by conventional depuration. The primary goal of the research is to quantify the risk of Norovirus infection in coastal waters through physically-based high-resolution numerical modelling. Cork Harbour and Clew Bay in Ireland provide case studies for the research. The models simulate a number of complex physical, chemical and biological processes which influence the <span class="hlt">transport</span> and decay of the virus as well as its bioaccumulation in oyster tissue. The current phase of the research is concerned with the adsorption of the virus to suspended <span class="hlt">sediment</span> in the water column. Adsorbed viruses may be taken out of the water column when <span class="hlt">sedimentation</span> occurs and, subsequently, be added to it with resuspension of the bed <span class="hlt">sediment</span>. Preliminary simulations of the Norovirus-<span class="hlt">sediment</span> model indicate that suspended <span class="hlt">sediment</span> can influence the <span class="hlt">transport</span> of the virus in coastal waters when a high <span class="hlt">sediment</span>-water partitioning coefficient is used and the model is run under calm environmental conditions. In this instance a certain fraction of the adsorbed viruses are taken out of the water column by <span class="hlt">sedimentation</span> and end up locked in the bed <span class="hlt">sediment</span>. Subsequently, under storm conditions, a large number of viruses in the bed are released into the water column by erosion of the bed and a risk of contamination occurs at a time different to when the viruses were initially released into the body of water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70040035','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70040035"><span>Currents, drag, and <span class="hlt">sediment</span> <span class="hlt">transport</span> induced by a tsunami</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lacy, Jessica R.; Rubin, David M.; Buscombe, Daniel</p> <p>2012-01-01</p> <p>We report observations of water surface elevation, currents, and suspended <span class="hlt">sediment</span> concentration (SSC) from a 10-m deep site on the inner shelf in northern Monterey Bay during the arrival of the 2010 Chile tsunami. Velocity profiles were measured from 3.5 m above the bed (mab) to the surface at 2 min intervals, and from 0.1 to 0.7 mab at 1 Hz. SSC was determined from the acoustic backscatter of the near-bed profiler. The initial tsunami waves were directed cross shore and had a period of approximately 16 min. Maximum wave height was 1.1 m, and maximum current speed was 0.36 m/s. During the strongest onrush, near-bed velocities were clearly influenced by friction and a logarithmic boundary layer developed, extending more than 0.3 mab. We estimated friction velocity and bed shear stress from the logarithmic profiles. The logarithmic structure indicates that the flow can be characterized as quasi-steady at these times. At other phases of the tsunami waves, the magnitude of the acceleration term was significant in the near-bed momentum equation, indicating unsteady flow. The maximum tsunami-induced bed shear stress (0.4 N/m2) exceeded the critical shear stress for the medium-grained sand on the seafloor. Cross-shore <span class="hlt">sediment</span> flux was enhanced by the tsunami. Oscillations of water surface elevation and currents continued for several days. The oscillations were dominated by resonant frequencies, the most energetic of which was the fundamental longitudinal frequency of Monterey Bay. The maximum current speed (hourly-timescale) in 18 months of observations occurred four hours after the tsunami arrived.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA505250','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA505250"><span><span class="hlt">Transport</span> of Gas and Solutes in Permeable Estuarine <span class="hlt">Sediments</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2008-01-01</p> <p>and determination of <span class="hlt">transport</span> rates, dispersion and interfacial flux of solutes and colloidal material. Participating Scientists and students ...Scientists and students participating in this work are Dr. Markus Huettel (PI), Dr. Parthasarathi Chakraborty (Postdoc), Sucharita Chakraborty (graduate... student ), Veronica Cruz (undergraduate student ) and Allison Rau (undergraduate student ). WORK COMPLETED Two field campaigns were conducted, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/37696','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/37696"><span>Potential effects of timber harvest and water management on streamflow dynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>C. A. Troendle; W. K. Olsen</p> <p>1994-01-01</p> <p>The sustainability of aquatic and riparian ecological systems is strongly tied to the dynamics of the streamflow regime. Timber harvest can influence the flow regime by increasing total flow, altering peak discharge rate, and changing the duration of flows of differing frequency of occurrence. These changes in the energy and <span class="hlt">sediment</span> <span class="hlt">transporting</span> capability of the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=40007&Lab=ORD&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=40007&Lab=ORD&keyword=finite+AND+element&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>USER'S MANUAL FOR THE INSTREAM <span class="hlt">SEDIMENT</span>-CONTAMINANT <span class="hlt">TRANSPORT</span> MODEL SERATRA</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This manual guides the user in applying the <span class="hlt">sediment</span>-contaminant <span class="hlt">transport</span> model SERATRA. SERATRA is an unsteady, two-dimensional code that uses the finite element computation method with the Galerkin weighted residual technique. The model has general convection-diffusion equatio...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=343713','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=343713"><span><span class="hlt">Transport</span> and fate of viruses in <span class="hlt">sediment</span> and stormwater from a managed aquifer recharge site</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Enteric viruses are one of the major concerns in water reclamation and reuse at managed aquifer recharge (MAR) sites. In this study, the <span class="hlt">transport</span> and fate of bacteriophages MS2, PRD1, and FX174 were studied in <span class="hlt">sediment</span> and stormwater (SW) collected from a MAR site in Parafield, Australia. Column ex...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA572764','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA572764"><span>A Numerical Modeling Framework for Cohesive <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Driven by Waves and Tidal Currents</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2012-09-30</p> <p>for <span class="hlt">sediment</span> <span class="hlt">transport</span>. The successful extension to multi-dimensions is benefited from an open-source CFD package, OpenFOAM (www.openfoam.org). This...linz.at/Drupal/), which couples the fluid solver OpenFOAM with the Discrete Element Model (DEM) solver LIGGGHTS (an improved LAMMPS for granular flow</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=331677','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=331677"><span>Insight into <span class="hlt">sediment</span> <span class="hlt">transport</span> processes on saline rangeland hillslopes using three-dimensional soil microtopography changes</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>In arid and semi-arid rangeland environments, an accurate understanding of runoff generation and <span class="hlt">sediment</span> <span class="hlt">transport</span> processes is key to developing effective management actions and addressing ecosystem response to changes. Yet, many primary processes (namely sheet and splash and concentrated flow ero...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMEP33B0851L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMEP33B0851L"><span>Nested modeling approach to quantify <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways and temporal variability of barrier island evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Long, J. W.; Dalyander, S.; Sherwood, C. R.; Thompson, D. M.; Plant, N. G.</p> <p>2012-12-01</p> <p>The Chandeleur Islands, situated off the coast of Louisiana in the Gulf of Mexico, comprise a sand-starved barrier island system that has been disintegrating over the last decade. The persistent <span class="hlt">sediment</span> <span class="hlt">transport</span> in this area is predominantly directed alongshore but overwash and inundation during storm conditions has fragmented the island and reduced the subaerial extent by almost 75% since 2001. From 2010-2011 a sand berm was constructed along the Gulf side of the island adding 20 million cubic yards of <span class="hlt">sediment</span> to this barrier island system. The redistribution of this <span class="hlt">sediment</span>, particularly whether it remains in the active system and progrades the barrier island, has been evaluated using a series of numerical models and an extensive set of in situ and remote sensing observations. We have developed a coupled numerical modeling system capable of simulating morphologic evolution of the sand berm and barrier island using observations and predictions of regional and nearshore oceanographic processes. A nested approach provides large scale oceanographic information to force island evolution in a series of smaller grids, including two nearshore domains that are designed to simulate (1) the persistent alongshore <span class="hlt">sediment</span> <span class="hlt">transport</span> O(months-years) and (2) the overwash and breaching of the island/berm due to cross-shore forcing driven by winter cold fronts and tropical storms (O(hours-days)). The coupled model is evaluated using the observations of waves, water levels, currents, and topographic/morphologic change. Modeled processes are then used to identify the dominant <span class="hlt">sediment</span> <span class="hlt">transport</span> pathways and quantify the role of alongshore and cross-shore <span class="hlt">sediment</span> <span class="hlt">transport</span> in evolving the barrier island over a range of temporal scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70021435','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70021435"><span><span class="hlt">Transport</span> of <span class="hlt">sediment</span>-bound organochlorine pesticides to the San Joaquin River, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kratzer, C.R.</p> <p>1999-01-01</p> <p>Suspended <span class="hlt">sediment</span> samples were collected in westside tributaries and the main stem of the San Joaquin River, California, in June 1994 during the irrigation season and in January 1995 during a winter storm. These samples were analyzed for 15 organochlorine pesticides to determine their occurrence and their concentrations on suspended <span class="hlt">sediment</span> and to compare <span class="hlt">transport</span> during the irrigation season (April to September) to <span class="hlt">transport</span> during winter storm runoff (October to March). Ten organochlorine pesticides were detected during the winter storm runoff; seven during the irrigation season. The most frequently detected organochlorine pesticides during both sampling periods were p,p'-DDE, p,p'-DDT, p,p'-DDD, dieldrin, toxaphene, and chlordane. Dissolved samples were analyzed for three organochlorine pesticides during the irrigation season and for 15 during the winter storm. Most calculated total concentrations of p,p'-DDT, chlordane, dieldrin, and toxaphene exceeded chronic criteria for the protection of freshwater aquatic life. At eight sites in common between sampling periods, suspended <span class="hlt">sediment</span> concentrations and streamflow were greater during the winter storm runoff median concentration of 3,590 mg/L versus 489 mg/and median streamflow of 162 ft3/s versus 11 ft3/s. Median concentrations of total DDT (sum of p,p'-DDD, p,p'-DDE, and p,p'-DDT), chlordane, dieldrin, and toxaphene on suspended <span class="hlt">sediment</span> were slightly greater during the irrigation season, but instantaneous loads of organochlorine pesticides at the time of sampling were substantially greater during the winter storm. Estimated loads for the entire irrigation season exceeded estimated loads for the January 1995 storm by about 2 to 4 times for suspended <span class="hlt">transport</span> and about 3 to 11 times for total <span class="hlt">transport</span>. However, because the mean annual winter runoff is about 2 to 4 times greater than the runoff during the January 1995 storm, mean winter <span class="hlt">transport</span> may be similar to irrigation season <span class="hlt">transport</span>. This conclusion</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.3231R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.3231R"><span>Improving <span class="hlt">sediment</span> <span class="hlt">transport</span> measurements in the Erlenbach stream using a moving basket system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rickenmann, Dieter; Turowski, Jens; Hegglin, Ramon; Fritschi, Bruno</p> <p>2010-05-01</p> <p>In the Erlenbach stream, a prealpine torrent in Switzerland, <span class="hlt">sediment</span> <span class="hlt">transport</span> has been monitored for more than 25 years. <span class="hlt">Sediment</span> <span class="hlt">transporting</span> flood events in the Erlenbach are typically of short duration with a rapid rise of discharge during summer thunderstorms, thus hampering on-site measurements. On average there are more than 20 bedload <span class="hlt">transport</span> events per year. Near the confluence with the main valley river, there is a stream gauging station and a <span class="hlt">sediment</span> retention basin with a capacity of about 2,000 m3. The basin is surveyed at regular intervals and after large flood events. In addition, <span class="hlt">sediment</span> <span class="hlt">transport</span> has been continuously monitored with a piezoelectric bedload impact sensor (PBIS) array since 1986. The sensor array is mounted flush with the surface of a check dam immediately upstream of the retention basin. The PBIS system was developed to continuously measure the intensity of bedload <span class="hlt">transport</span> and its relation to stream discharge. To standardize the sensors, the piezoelectric crystals were replaced by geophones in 2000. The geophone measuring system has also been employed at a number of other streams. In 2008, the measuring system in the Erlenbach stream has been enhanced with an automatic system to obtain bedload samples. Movable, slot-type cubic metal baskets are mounted on a rail at the downstream wall of the large check dam above the retention basin. The metal baskets can be moved automatically and individually into the flow according to flow and bedload <span class="hlt">transport</span> conditions (i.e. geophone recordings). The basket is stopped at the centerline of the approach flow channel of the overflow section to obtain a <span class="hlt">sediment</span> sample during a limited time interval. The wire mesh of the basket has a spacing of 10 mm to sample all <span class="hlt">sediment</span> particles coarser than this size (which is about the limiting grain size detected by the geophones). The weight increase due to the collected <span class="hlt">sediment</span> is measured by weighing cells located in the basket supporting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4692308','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4692308"><span>Reconstructing the <span class="hlt">transport</span> history of pebbles on Mars</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Szabó, Tímea; Domokos, Gábor; Grotzinger, John P.; Jerolmack, Douglas J.</p> <p>2015-01-01</p> <p>The discovery of remarkably rounded pebbles by the rover Curiosity, within an exhumed alluvial fan complex in Gale Crater, presents some of the most compelling evidence yet for sustained fluvial activity on Mars. While rounding is known to result from abrasion by inter-particle collisions, geologic interpretations of <span class="hlt">sediment</span> shape have been qualitative. Here we show how quantitative information on the <span class="hlt">transport</span> distance of river pebbles can be extracted from their shape alone, using a combination of theory, laboratory experiments and terrestrial field data. We determine that the Martian basalt pebbles have been carried tens of kilometres from their source, by <span class="hlt">bed-load</span> <span class="hlt">transport</span> on an alluvial fan. In contrast, angular clasts strewn about the surface of the Curiosity traverse are indicative of later emplacement by rock fragmentation processes. The proposed method for decoding <span class="hlt">transport</span> history from particle shape provides a new tool for terrestrial and planetary sedimentology. PMID:26460507</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMOS21B1224V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMOS21B1224V"><span>The South Carolina Coastal Erosion Study: Integrated Circulation and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> Studies. A Project Overview.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Voulgaris, G.; Warner, J. C.; Work, P. A.; Hanes, D. M.; Haas, K. A.</p> <p>2004-12-01</p> <p>The South Carolina Coastal Erosion Study (SCCES) is a cooperative research program funded by the U.S. Geological Survey Coastal and Marine Geology Program and managed by the South Carolina Sea Grant Consortium. The main objective of the study is to understand the factors and processes that control coastal <span class="hlt">sediment</span> movement along the northern part of the South Carolina coast while at the same time advance our basic understanding of circulation, wave propagation and <span class="hlt">sediment</span> <span class="hlt">transport</span> processes. Earlier geological framework studies carried out by the same program provided detailed data on bathymetry, bottom <span class="hlt">sediment</span> thickness and grain size distribution. They identified an extensive (10km long, 2km wide) sand body deposit located in the inner shelf that has potential use for beach nourishment. The main objectives are to: (1) identify the role of wind-driven circulation in controlling regional <span class="hlt">sediment</span> distribution on the SC shelf; (2) examine the hypothesis that the shoal is of the "fair-weather type" with bedload being the dominant <span class="hlt">sediment</span> <span class="hlt">transport</span> mode and the tidally-averaged flow being at different directions at the two flanks of the shoal; (3) investigate the possibility that the <span class="hlt">sediment</span> source for the shoal is derived from the nearshore as the result of the convergence of the longshore <span class="hlt">sediment</span> <span class="hlt">transport</span>; and finally, (4) quantify the control that the shoal exerts on the nearshore conditions through changes on the wave energy propagation characteristics. Field measurements and numerical modeling techniques are utilized in this project. Two deployments of oceanographic and <span class="hlt">sediment</span> <span class="hlt">transport</span> systems took place for a period of 6 months (October 2003 to April 2004) measuring wind forcing, vertical distribution of currents, stratification, and wave spectral characteristics. Further, bed-flow interactions were measured at two locations, with instrumented tripods equipped with pairs of ADVs for measuring turbulence, PC-ADPs for measuring vertical current profiles</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.2592Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.2592Z"><span>Modelling Suspended <span class="hlt">Sediment</span> <span class="hlt">Transport</span> in Monsoon Season: A Case Study of Pahang River Estuary, Pahang, Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zakariya, Razak; Ahmad, Zuhairi; Saad, Shahbudin; Yaakop, Rosnan</p> <p>2013-04-01</p> <p><span class="hlt">Sediment</span> <span class="hlt">transport</span> based on 2-dimensional real time model was applied to Pahang River estuary, Pahang, Malaysia and has been evaluated and verified with time series of tidal elevation, flow and suspended <span class="hlt">sediment</span> load. Period of modelling was during highest high tide and lowest low tide in Northeast Monsoon (NE) which happened in December 2010 and Southwest Monsoon (SW) in July 2011. Simulated model outputs has been verify using Pearson's coefficient and has showed high accuracy. The validated model was used to simulate hydrodynamic and <span class="hlt">sediment</span> <span class="hlt">transport</span> of extreme conditions during both monsoon seasons. Based on field measurement and model simulation, tidal elevation and flow velocity, freshwater discharge of Pahang River were found to be higher during NE Monsoon. Based on the fluxes, the estuary also showed 'ebb-dominant' characteristic during highest high tide and lowest low tide in NE monsoon and normal ebbing-flooding characteristics during SW monsoon. In the Pahang River estuary, inflow and outflow patterns were perpendicular to the open boundary with circular flow formed at the shallow area in the middle of estuary during both monsoons. Referring to sea water intrusion from the river mouth, both seasons show penetration of more than 9 km (upstream input boundary) during higher high water tide. During higher lower water tide, the water intrusion stated varies which 5.6km during NE monsoon and 7.8km during SW monsoon. Regarding to the times lap during high tide, the sea water takes 2.8 hours to reach 9km upstream during NE monsoon compared to 1.9 hour during SW monsoon. The averages of suspended <span class="hlt">sediment</span> concentration and suspended <span class="hlt">sediment</span> load were higher during Northeast monsoon which increased the <span class="hlt">sedimentation</span> potentials.Total of suspended <span class="hlt">sediment</span> load discharged to the South China Sea yearly from Pahang River is approximately 96727.5 tonnes/day or 3.33 tonnes/km2/day which 442.6 tonnes/day during Northeast Monsoon and 25.3 tonnes/day during Southwest</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H51E0794G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H51E0794G"><span>Coarse <span class="hlt">sediment</span> <span class="hlt">transport</span> dynamics at three spatial scales of bedrock channel bed complexity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goode, J. R.; Wohl, E.</p> <p>2007-12-01</p> <p>Rivers incised into bedrock in fold-dominated terrain display a complex bed topography that strongly interacts with local hydraulics to produce spatial differences in bed <span class="hlt">sediment</span> flux. We used painted tracer clasts to investigate how this complex bed topography influences coarse <span class="hlt">sediment</span> <span class="hlt">transport</span> at three spatial scales (reach, cross- section and grain). The study was conducted along the Ocoee River gorge, Tennessee between the TVA Ocoee #3 dam and the 1996 Olympic whitewater course. The bed topography consists of undulating bedrock ribs, which are formed at a consistent strike to the bedding and cleavage of the metagreywake and phyllite substrate. Ribs vary in their orientation to flow (from parallel to oblique) and amplitude among three study reaches. These bedrock ribs create a rough bed topography that substantially alters the local flow field and influences reach- scale roughness. In each reach, 300 tracer clasts were randomly selected from the existing bed material. Tracer clasts were surveyed and <span class="hlt">transport</span> distances were calculated after five scheduled summer releases and a suite of slightly larger but sporadic winter releases. <span class="hlt">Transport</span> distances were examined as a function of rib orientation and amplitude (reach scale), spatial proximity to bedrock ribs and standard deviation of the bed elevation (cross- section scale), and whether clasts were hydraulically shielded by surrounding clasts, incorporated in the armour layer, imbricated, and/or existed in a pothole, in addition to size and angularity. At the reach scale, where ribs are parallel to flow, lower reach-scale roughness leads to greater <span class="hlt">sediment</span> <span class="hlt">transport</span> capacity, <span class="hlt">sediment</span> flux and <span class="hlt">transport</span> distances because <span class="hlt">transport</span> is uninhibited in the downstream direction. Preliminary results indicate that cross section scale characteristics of bed topography exert a greater control on <span class="hlt">transport</span> distances than grain size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70175909','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70175909"><span>The timing of <span class="hlt">sediment</span> <span class="hlt">transport</span> down Monterey Submarine Canyon, offshore California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stevens, Thomas; Paull, Charles K.; Ussler, William III; McGann, Mary; Buylaert, Jan-Pieter; Lundsten, Eve M.</p> <p>2013-01-01</p> <p>While submarine canyons are the major conduits through which <span class="hlt">sediments</span> are <span class="hlt">transported</span> from the continents out into the deep sea, the time it takes for <span class="hlt">sediment</span> to pass down through a submarine canyon system is poorly constrained. Here we report on the first study to couple optically stimulated luminescence (OSL) ages of quartz sand deposits and accelerator mass spectrometry 14C ages measured on benthic foraminifera to examine the timing of <span class="hlt">sediment</span> <span class="hlt">transport</span> through the axial channel of Monterey Submarine Canyon and Fan, offshore California. The OSL ages date the timing of <span class="hlt">sediment</span> entry into the canyon head while the 14C ages of benthic foraminifera record the deposition of hemipelagic <span class="hlt">sediments</span> that bound the sand horizons. We use both single-grain and small (∼2 mm area) single-aliquot regeneration approaches on vibracore samples from fining-upward sequences at various water depths to demonstrate relatively rapid, decadal-scale sand <span class="hlt">transport</span> to at least 1.1 km depth and more variable decadal- to millennial-scale <span class="hlt">transport</span> to a least 3.5 km depth on the fan. Significant differences between the time sand was last exposed at the canyon head (OSL age) and the timing of deposition of the sand (from 14C ages of benthic foraminifera in bracketing hemipelagic <span class="hlt">sediments</span>) are interpreted as indicating that the sand does not pass through the entire canyon instantly in large individual events, but rather moves multiple times before emerging onto the fan. The increased spread in single-grain OSL dates with water depth provides evidence of mixing and temporary storage of <span class="hlt">sediment</span> as it moves through the canyon system. The ages also indicate that the frequency of <span class="hlt">sediment</span> <span class="hlt">transport</span> events decreases with distance down the canyon channel system. The amalgamated sands near the canyon head yield OSL ages that are consistent with a sub-decadal recurrence frequency while the fining-upward sand sequences on the fan indicate that the channel is still experiencing events with a 150</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP41C1850S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP41C1850S"><span>Evaluating <span class="hlt">sediment</span> <span class="hlt">transport</span> in flood-driven ephemeral tributaries using direct and acoustic methods.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stark, K.</p> <p>2017-12-01</p> <p>One common source of uncertainty in <span class="hlt">sediment</span> <span class="hlt">transport</span> modeling of large semi-arid rivers is <span class="hlt">sediment</span> influx delivered by ephemeral, flood-driven tributaries. Large variations in <span class="hlt">sediment</span> delivery are associated with these regimes due to the highly variable nature of flows within them. While there are many <span class="hlt">sediment</span> <span class="hlt">transport</span> equations, they are typically developed for perennial streams and can be inaccurate for ephemeral channels. Discrete, manual sampling is labor intensive and requires personnel to be on site during flooding. In addition, flooding within these tributaries typically last on the order of hours, making it difficult to be present during an event. To better understand these regimes, automated systems are needed to continuously sample bedload and suspended load. In preparation for the pending installation of an automated site on the Arroyo de los Piños in New Mexico, manual <span class="hlt">sediment</span> and flow samples have been collected over the summer monsoon season of 2017, in spite of the logistical challenges. These data include suspended and bedload <span class="hlt">sediment</span> samples at the basin outlet, and stage and precipitation data from throughout the basin. Data indicate a complex system; flow is generated primarily in areas of exposed bedrock in the center and higher elevations of the watershed. Bedload samples show a large coarse-grained fraction, with 50% >2 mm and 25% >6 mm, which is compatible with acoustic measuring techniques. These data will be used to inform future site operations, which will combine direct <span class="hlt">sediment</span> measurement from Reid-type slot samplers and non-invasive acoustic measuring methods. Bedload will be indirectly monitored using pipe-style microphones, plate-style geophones, channel hydrophones, and seismometers. These instruments record vibrations and acoustic signals from bedload impacts and movement. Indirect methods for measuring of bedload have never been extensively evaluated in ephemeral channels in the southwest United States. Once calibrated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP53C1754N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP53C1754N"><span><span class="hlt">Transport</span> of <span class="hlt">sediment</span> through a channel network during a post-fire debris flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nyman, P.; Box, W. A. C.; Langhans, C.; Stout, J. C.; Keesstra, S.; Sheridan, G. J.</p> <p>2017-12-01</p> <p><span class="hlt">Transport</span> processes linking <span class="hlt">sediment</span> in steep headwaters with rivers during high magnitude events are rarely examined in detail, particularly in forested settings where major erosion events are rare and opportunities for collecting data are limited. Yet high magnitude events in headwaters are known to drive landscape change. This study examines how a debris flow after wildfire impacts on <span class="hlt">sediment</span> <span class="hlt">transport</span> from small headwaters (0.02 km2) through a step pool stream system within a larger 14 km2 catchment, which drains into the East Ovens River in SE Australia. <span class="hlt">Sediment</span> delivery from debris flows was modelled and downstream deposition of <span class="hlt">sediment</span> was measured using a combination of aerial imagery and field surveys. Particle size distributions were measured for all major deposits. These data were summarised to map <span class="hlt">sediment</span> flux as a continuous variable over the drainage network. Total deposition throughout the stream network was 39 x 103 m3. Catchment efflux was 61 x 103 m3 (specific <span class="hlt">sediment</span> yield of 78 ton ha-1), which equates to 400-800 years of background erosion, based on measurements in nearby catchments. Despite the low gradient (ca. 0.1 m m-1) of the main channel there was no systematic downstream sorting in <span class="hlt">sediment</span> deposits in the catchment. This is due to debris flow processes operating throughout the stream network, with lateral inputs sustaining the process in low gradient channels, except in the most downstream reaches where the flow transitioned towards hyper-concentrated flow. Overall, a large proportion ( 88%) of the eroded fine fraction (<63 micron) exited the catchment, when compared to the overall ratio (55%) of erosion to deposition. The geomorphic legacy of this post-wildfire event depends on scale. In the lower channels (steam order 4-5), where erosion was nearly equal to deposition, the event had no real impact on total <span class="hlt">sediment</span> volumes stored. In upper channels (stream orders < 3) erosion was widespread but deposition rates were low. So</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70001404','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70001404"><span>Role of reef fauna in <span class="hlt">sediment</span> <span class="hlt">transport</span> and distribution - Studies from Tektite I and II</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Clifton, H.E.</p> <p>1973-01-01</p> <p>1. Reef organisms may play a major role in the <span class="hlt">transport</span> and distribution of <span class="hlt">sediment</span> on the sea floor adjacent to coral reefs. 2. Some fish such as Malacanthus plumieri (Bloch) selectively <span class="hlt">transport</span> and collect certain types of <span class="hlt">sediment</span> (such as larger coral and shell fragments). 3. The random movement of crawling or burrowing organisms may cause a large amount of <span class="hlt">sediment</span> to be shifted laterally on the sea floor. On slopes, a net downhill displacement may result. 4. The surface configuration and internal structure of the <span class="hlt">sediment</span> is rapidly changed by faunal mixing. Ripple marks formed by waves or currents are obliterated by the activity of organisms in only a few weeks in the environment studied. Internal structure (bedding) near the <span class="hlt">sediment</span>-water interface is similarly destroyed in a short period of time. 5. Larger clasts (including empty shells) on the sea floor tend to be buried by faunal undermining. The rate of burial depends primarily on the grain size of the substrate. 6. The random movement of fauna on the sea floor may produce a predominantly concave-up orientation of pelecypod shells and shell fragments on the sea floor - the opposite of that produced by the activity of waves or currents. ?? 1973 Biologischen Anstalt Helgoland.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP13F..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP13F..02B"><span>Fine <span class="hlt">Sediment</span> Erosion and <span class="hlt">Transport</span> to the Near Coastal Zone from Watersheds of St. Thomas, USVI</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benoit, G.; Xuan, Z.</p> <p>2014-12-01</p> <p>The US Virgin Islands' landscape is characterized by steep slopes and short distances from ridge peaks to fringing reefs. Fine-grained <span class="hlt">sediments</span> eroded from predominantly thin soils may be <span class="hlt">transported</span> rapidly by streams (locally called guts) to the sea and cause stress to corals. We have studied erosion and <span class="hlt">transport</span> processes on St Thomas by three methods: (1) continuous monitoring of suspended matter in one of the island's few perennial streams, Dorothea Gut, (2) measurement of 137Cs inventories in soil cores taken across the landscape, and (3) evaluation of <span class="hlt">sediment</span> captured in most of the island's coastal ponds, through which a significant portion of runoff must pass. We find that, for areas that have not been recently disturbed, watersheds retain fine <span class="hlt">sediments</span> surprisingly well. On the other hand, small patches of land, like building lots that have been recently disturbed and poorly managed, can produce disproportionate amounts of fine <span class="hlt">sediment</span>. These results differ somewhat from nearby St John, USVI, where unpaved roads are the major source of eroded <span class="hlt">sediments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GML....38..167L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GML....38..167L"><span><span class="hlt">Sediment</span> <span class="hlt">transport</span> processes in the Pearl River Estuary as revealed by grain-size end-member modeling and <span class="hlt">sediment</span> trend analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Tao; Li, Tuan-Jie</p> <p>2018-04-01</p> <p>The analysis of grain-size distribution enables us to decipher <span class="hlt">sediment</span> <span class="hlt">transport</span> processes and understand the causal relations between dynamic processes and grain-size distributions. In the present study, grain sizes were measured from surface <span class="hlt">sediments</span> collected in the Pearl River Estuary and its adjacent coastal areas. End-member modeling analysis attempts to unmix the grain sizes into geologically meaningful populations. Six grain-size end-members were identified. Their dominant modes are 0 Φ, 1.5 Φ, 2.75 Φ, 4.5 Φ, 7 Φ, and 8 Φ, corresponding to coarse sand, medium sand, fine sand, very coarse silt, silt, and clay, respectively. The spatial distributions of the six end-members are influenced by <span class="hlt">sediment</span> <span class="hlt">transport</span> and depositional processes. The two coarsest end-members (coarse sand and medium sand) may reflect relict <span class="hlt">sediments</span> deposited during the last glacial period. The fine sand end-member would be difficult to <span class="hlt">transport</span> under fair weather conditions, and likely indicates storm deposits. The three remaining fine-grained end-members (very coarse silt, silt, and clay) are recognized as suspended particles <span class="hlt">transported</span> by saltwater intrusion via the flood tidal current, the Guangdong Coastal Current, and riverine outflow. The grain-size trend analysis shows distinct <span class="hlt">transport</span> patterns for the three fine-grained end-members. The landward <span class="hlt">transport</span> of the very coarse silt end-member occurs in the eastern part of the estuary, the seaward <span class="hlt">transport</span> of the silt end-member occurs in the western part, and the east-west <span class="hlt">transport</span> of the clay end-member occurs in the coastal areas. The results show that grain-size end-member modeling analysis in combination with <span class="hlt">sediment</span> trend analysis help to better understand <span class="hlt">sediment</span> <span class="hlt">transport</span> patterns and the associated <span class="hlt">transport</span> mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP24A..01P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP24A..01P"><span>Creepy landscapes : river <span class="hlt">sediment</span> entrainment develops granular flow rheology on creeping bed.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prancevic, J.; Chatanantavet, P.; Ortiz, C. P.; Houssais, M.; Durian, D. J.; Jerolmack, D. J.</p> <p>2015-12-01</p> <p>To predict rates of river <span class="hlt">sediment</span> <span class="hlt">transport</span>, one must first address the zeroth-order question: when does <span class="hlt">sediment</span> move? The concept and determination of the critical fluid shear stress remains hazy, as observing particle motion and determining <span class="hlt">sediment</span> flux becomes increasingly hard in its vicinity. To tackle this problem, we designed a novel annular flume experiment - reproducing an infinite river channel - where the refractive index of particles and the fluid are matched. The fluid is dyed with a fluorescent powder and a green laser sheet illuminates the fluid only, allowing us to observe particle displacements in a vertical plane. Experiments are designed to highlight the basic granular interactions of <span class="hlt">sediment</span> <span class="hlt">transport</span> while suppressing the complicating effects of turbulence; accordingly, particles are uniform spheres and Reynolds numbers are of order 1. We have performed <span class="hlt">sediment</span> <span class="hlt">transport</span> measurements close to the onset of particle motion, at steady state, and over long enough time to record averaged rheological behavior of particles. We find that particles entrained by a fluid exhibit successively from top to bottom: a suspension regime, a dense granular flow regime, and - instead of a static bed - a creeping regime. Data from experiments at a range of fluid stresses can be collapsed onto one universal rheologic curve that indicates the effective friction is a monotonic function of a dimensionless number called the viscous number. These data are in remarkable agreement with the local rheology model proposed by Boyer et al., which means that dense granular flows, suspensions and <span class="hlt">bed-load</span> <span class="hlt">transport</span> are unified under a common frictional flow law. Importantly, we observe slow creeping of the granular bed even in the absence of <span class="hlt">bed</span> <span class="hlt">load</span>, at fluid stresses that are below the apparent critical value. This last observation challenges the classical definition of the onset of <span class="hlt">sediment</span> <span class="hlt">transport</span>, and points to a continuous transition from quasi-static deformation to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.2281S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.2281S"><span>Theory connecting nonlocal <span class="hlt">sediment</span> <span class="hlt">transport</span>, earth surface roughness, and the Sadler effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schumer, Rina; Taloni, Alessandro; Furbish, David Jon</p> <p>2017-03-01</p> <p>Earth surface evolution, like many natural phenomena typified by fluctuations on a wide range of scales and deterministic smoothing, results in a statistically rough surface. We present theory demonstrating that scaling exponents of topographic and stratigraphic statistics arise from long-time averaging of noisy surface evolution rather than specific landscape evolution processes. This is demonstrated through use of "elastic" Langevin equations that generically describe disturbance from a flat earth surface using a noise term that is smoothed deterministically via <span class="hlt">sediment</span> <span class="hlt">transport</span>. When smoothing due to <span class="hlt">transport</span> is a local process, the geologic record self organizes such that a specific Sadler effect and topographic power spectral density (PSD) emerge. Variations in PSD slope reflect the presence or absence and character of nonlocality of <span class="hlt">sediment</span> <span class="hlt">transport</span>. The range of observed stratigraphic Sadler slopes captures the same smoothing feature combined with the presence of long-range spatial correlation in topographic disturbance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25497429','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25497429"><span><span class="hlt">Transport</span> of U(VI) through <span class="hlt">sediments</span> amended with phosphate to induce in situ uranium immobilization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mehta, Vrajesh S; Maillot, Fabien; Wang, Zheming; Catalano, Jeffrey G; Giammar, Daniel E</p> <p>2015-02-01</p> <p>Phosphate amendments can be added to U(VI)-contaminated subsurface environments to promote in situ remediation. The primary objective of this study was to evaluate the impacts of phosphate addition on the <span class="hlt">transport</span> of U(VI) through contaminated <span class="hlt">sediments</span>. In batch experiments using <span class="hlt">sediments</span> (<2 mm size fraction) from a site in Rifle, Colorado, U(VI) only weakly adsorbed due to the dominance of the aqueous speciation by Ca-U(VI)-carbonate complexes. Column experiments with these <span class="hlt">sediments</span> were performed with flow rates that correspond to a groundwater velocity of 1.1 m/day. In the absence of phosphate, the <span class="hlt">sediments</span> took up 1.68-1.98 μg U/g of <span class="hlt">sediments</span> when the synthetic groundwater influent contained 4 μM U(VI). When U(VI)-free influents were then introduced with and without phosphate, substantially more uranium was retained within the column when phosphate was present in the influent. Sequential extractions of <span class="hlt">sediments</span> from the columns revealed that uranium was uniformly distributed along the length of the columns and was primarily in forms that could be extracted by ion exchange and contact with a weak acid. Laser induced fluorescence spectroscopy (LIFS) analysis along with sequential extraction results suggest adsorption as the dominant uranium uptake mechanism. The response of dissolved uranium concentrations to stopped-flow events and the comparison of experimental data with simulations from a simple reactive <span class="hlt">transport</span> model indicated that uranium adsorption to and desorption from the <span class="hlt">sediments</span> was not always at local equilibrium. Copyright © 2014 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMGC23C1075H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMGC23C1075H"><span>A Numerical Study of Hydrodynamics and <span class="hlt">Sediment</span> <span class="hlt">Transport</span> in Fourleague Bay, Louisiana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, K.; Chen, Q. J.; Xu, K.; Bentley, S. J.; WANG, J.</p> <p>2017-12-01</p> <p>Fourleague Bay is a shallow and vertically well-mixed estuary in south-central Louisiana. This estuary is highly impacted by wind (e.g., cold fronts and tropical storms), river discharge from the Atchafalaya River and tides from the Gulf of Mexico, and is being used as an analog site to study impacts of <span class="hlt">sediment</span>-diversion restoration strategies in the Mississippi River Delta. In this study, a coupled flow-wave Delft3D model was setup and applied to study hydrodynamics and <span class="hlt">sediment</span> <span class="hlt">transport</span> in this area. The model grid size is 1071x631 with a 50-m resolution in the bay. Vegetation is considered by rigid cylinders in both flow and wave modules. The offshore water level boundary conditions were provided by a Gulf-scale Delft3D model. Model parameters, especially for cohesive <span class="hlt">sediment</span> <span class="hlt">transport</span> such as settling velocity, erosion rate and critical bottom shear stress, were calibrated using the field observation data during three seasons from May 2015 to March 2016. The modeled water levels, currents, significant wave heights and suspended <span class="hlt">sediment</span> concentrations agreed fairly well with measurements, which suggests a reasonable model performance. Seasonal variations were analyzed based on different scenarios. A series of numerical experiments were set up to quantify the contributions of different factors, such as river discharge, tides and waves to <span class="hlt">sediment</span> <span class="hlt">transport</span> in this area. This model will be further applied to be part of a landscape ecosystem model to test landscape and population change over time with manipulations to <span class="hlt">sediment</span> delivery. This study was funded by the National Science Foundation (SEES-1427389 and CCF-1539567).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993Icar..103..276D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993Icar..103..276D"><span>Atmospheric tides on Venus. IV - Topographic winds and <span class="hlt">sediment</span> <span class="hlt">transport</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dobrovolskis, A. R.</p> <p>1993-06-01</p> <p>A novel theory is presented for the Venus boundary layer which encompasses the effects of topography and uses the mixing-length hypothesis to preclude the unknown eddy viscosity. The maps of mass-flux and erosion/deposition rate presented are based on Pioneer Venus orbiter relief measurements. The typically 19 cm/sec friction speeds associated with the present theory are several times greater than those estimated on the basis of Venera 9 and 10 anemometry, and mean aeolian <span class="hlt">transport</span> is generally away from the equator, contrary to Magellan orbiter windstreak directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740004025','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740004025"><span>California coast nearshore processes study. [nearshore currents, <span class="hlt">sediment</span> <span class="hlt">transport</span>, estuaries, and river discharge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pirie, D. M.; Steller, D. D. (Principal Investigator)</p> <p>1973-01-01</p> <p>The author has identified the following significant results. Large scale <span class="hlt">sediment</span> plumes from intermittent streams and rivers form detectable seasonal patterns on ERTS-1 imagery. The ocean current systems, as plotted from three California coast ERTS mosaics, were identified. Offshore patterns of <span class="hlt">sediment</span> in areas such as the Santa Barbara Channel are traceable. These patterns extend offshore to heretofore unanticipated ranges as shown on the ERTS-1 imagery. Flying spot scanner enhancements of NASA tapes resulted in details of subtle and often invisible (to the eye) nearshore features. The suspended <span class="hlt">sediments</span> off San Francisco and in Monterey Bay are emphasized in detail. These are areas of extremely changeable offshore <span class="hlt">sediment</span> <span class="hlt">transport</span> patterns. Computer generated contouring of radiance levels resulted in maps that can be used in determining surface and nearsurface suspended <span class="hlt">sediment</span> distribution. Tentative calibrations of ERTS-1 spectral brightness against <span class="hlt">sediment</span> load have been made using shipboard measurements. Information from the combined enhancement and interpretation techniques is applicable to operational coastal engineering programs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H31D1428Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H31D1428Q"><span>Characteristics of <span class="hlt">Sediment</span> <span class="hlt">Transportation</span> in Two Contrasting Oak Forested Watersheds in the Lesser Central Himalaya, India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qazi, N. U. Q.; Bruijnzeel, S., Sr.; Rai, S. P., Sr.</p> <p>2015-12-01</p> <p><span class="hlt">Sediment</span> transfer from mountainous areas to lowland areas is one of the most important geomorphological processes globally with the bulk of the <span class="hlt">sediment</span> yield from such areas typically deriving from mass wastage processes. This study presents monthly, seasonal and annual variations in <span class="hlt">sediment</span> <span class="hlt">transport</span> (both suspended load and bedload) as well as dissolved loads over three consecutive water years (2008-2011) for two small forested watersheds with contrasting levels of forest disturbance in the Lesser Himalaya of Northwest India. Seasonal and annual suspended <span class="hlt">sediment</span> yields were strongly influenced by amounts of rainfall and streamflow and showed a 10-63 fold range between wet and dry years. Of the annual load, some 93% was produced on average during the monsoon season (June-September). <span class="hlt">Sediment</span> production by the disturbed forest catchment was 1.9-fold (suspended <span class="hlt">sediment</span>) to 5.9-fold (bedload) higher than that for the well-stocked forest catchment. By contrast, dissolved loads varied much less between years, seasons (although minimal during the dry summer season), and degree of forest disturbance. Total mechanical denudation rates were 1.6 times and 4.6 times larger than chemical denudation rates for the little disturbed and the heavily disturbed forest catchment, respectively whereas overall denudation rates were estimated at 0.69 and 1.04 mm per 1000 years, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/pp/1347/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/pp/1347/report.pdf"><span><span class="hlt">Sediment</span> sources and <span class="hlt">transport</span> in Kings Bay and vicinity, Georgia and Florida, July 8-16, 1982</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Radtke, D.B.</p> <p>1985-01-01</p> <p>Water quality, bottom-material, suspended-<span class="hlt">sediment</span>, and current velocity data were collected during July 1982 in Kings Bay and vicinity to provide information on the source and <span class="hlt">transport</span> of estuarine <span class="hlt">sediments</span>. Kings Bay and Cumberland Sound, the site of the Poseidon Submarine Base in southeast Georgia, are experiencing high rates of <span class="hlt">sediment</span> deposition and accumulation, which are causing serious navigational and operational problems. Velocity, bathymetry, turbidity, and bottom-material data suggest <span class="hlt">sediment</span> <span class="hlt">transported</span> from lower Kings Bay is accumulating deposits of suspended <span class="hlt">sediment</span> <span class="hlt">transported</span> from Cumberland Sound on the floodtide and from upper Kings Bay and the tidal march drained by Marianna Creek on the ebbtide. Suspended-<span class="hlt">sediment</span> discharges computed for consecutive 13-hr ebbtides and floodtides showed that a net quantity of suspended <span class="hlt">sediment</span> was <span class="hlt">transported</span> seaward from upper Kings Bay and Marianna Creek. A net landward <span class="hlt">transport</span> of suspended <span class="hlt">sediment</span> computed at the St. Marys Entrance indicated areas seaward of St. Marys Entrance may be supplying <span class="hlt">sediment</span> to the shoaling areas of the estuary, including lower Kings Bay. (USGS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMEP13B1623K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMEP13B1623K"><span>Mechanisms of <span class="hlt">Sediment</span> <span class="hlt">Transport</span> to an Abandoned Distributary Channel on the Huanghe (Yellow River) Delta, China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumpf, L. L.; Kineke, G. C.; Carlson, B.; Mullane, M.</p> <p>2017-12-01</p> <p>Avulsions on the fine-grained Huanghe delta have left it scarred with traces of abandoned distributary channels that become intertidal systems, open to water and <span class="hlt">sediment</span> exchange with the sea. In 1996, an engineered avulsion of the Huanghe left a 30 km long abandoned channel to the south of the modern active river channel. Though all fluvial input was cut off, present-day <span class="hlt">sedimentation</span> on the new tidal flats has been observed at rates around 2 cm/yr. The source must be suspended-<span class="hlt">sediment</span> from the Bohai Sea conveyed by the tidal channel network, but the mechanisms promoting <span class="hlt">sediment</span> import are unknown. Possible mechanisms include (A) import sourced from the <span class="hlt">sediment</span>-rich buoyant coastal plume, (B) wave resuspension on the shallow shelf, (C) reverse-estuarine residual circulation in the tidal channel, and (D) tidal asymmetry in the channel. Over three summers, in situ measurements of current velocity, suspended-<span class="hlt">sediment</span> concentration (SSC), and wave climate were made on the delta front, and measurements of velocity, SSC, and salinity were made within the tidal channel. Results suggest that the buoyant plume from the active Huanghe channel can <span class="hlt">transport</span> <span class="hlt">sediment</span> south toward the tidal channel mouth (A). Additionally, wave resuspension (B) takes place on the subaqueous topset beds when the significant wave height exceeds 1 m, providing potential sources of suspended-<span class="hlt">sediment</span> to the tidal channel. Within the abandoned channel, the tidal channel can become hypersaline and exhibit reverse-estuarine circulation (C), which would promote import of turbid coastal water near the surface. Time-series of velocity in the tidal channel indicate that ebb currents are consistently higher than flood currents through the spring-neap cycle (D), with maximum velocities exceeding 1 m/s and corresponding maximum SSC reaching 2 g/L during spring tide. While ebb dominance would typically tend to flush the system of its <span class="hlt">sediment</span> over time, <span class="hlt">sediment</span> supplied to the tidal flats may not be</p> </li>