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Showing 1 to 20 of 73 for “"Bedload"”.
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Fluvial bedrock abrasion by bedload : process and form
… erosion in bedrock river incision: abrasion by bedload. Both long term landscape evolution and physical process based models of bedrock incision would benefit from a better understanding of the controls and behaviour of the abrasion process in natural substrates and settings. A field .campaign …
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Tidal velocity asymmetries and bedload transport in shallow embayments
… elevation asymmetry and ratio of flood-to-ebb bedload transport is calculated for both the linear relation between elevation and velocity and the nonlinear relation. Results show that the ratio of flood·to-ebb bedload transport as calculated from the nonlinear relation between elevation and …
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Tidal velocity asymmetries and bedload transport in shallow embayments
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1987.
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The Impact of Vegetation Morphology on Turbulence and Bedload Transport
… constant channel average velocity revealed that bedload transport was predominantly correlated with near-bed turbulence, but was also weakly correlated with near-bed velocity. First, in emergent canopies, if vegetation was not clustered, turbulent kinetic energy (TKE) and bedload transport did …
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Improvement of Signal Analysis for Surrogate Bedload Monitoring at Sediment Bypass Tunnels
付記する学位プログラム名: グローバル生存学大学院連携プログラム
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Bedload Transport, Self Acceleration, Downstream Sorting, and Flow Dynamics of Turbidity Currents
… The plastic particles are carried mostly as bedload. Succession sustained flows are allowed to create a deposit behind a barrier that simulates the downstream end of a minibasin. The flows are introduced in the supercritical regime; the downstream barrier forces an internal hydraulic jump to …
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Bedload Transport in Gravel-Bed Streams under a wide range of Shields Stresses
Bedload transport is a complicated phenomenon in gravel-bed streams. Several factors account for this complication, including the different hydrologic regime under which different stream types operate and the wide range of particle sizes of channel bed material. Based on the hydrologic regime, …
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Trapping Efficiencies for the BLH-84, Helley-Smith, Elwha, and TR-2 Bedload Samplers
Bedload-trapping efficiencies for four types of pressure-difference bedload samplers – a standard Helley-Smith (intake-nozzle width and height of 76.2 mm x 76.2 mm), BLH-84 (76.2 mm x 76.2 mm), Elwha (203 mm x 102 mm) and Toutle River-2 (305 mm x 152 mm) a standard Helley-Smith, US BLH-84 (both …
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Modeling the Biogenic Effects of Freshwater Mollusks on Bedload Transport and Dynamics in a Gravel-Bedded Stream
Application of physical modeling in relation to the influence of ecosystem engineers such as the freshwater mussel has been a common source of interest in ecohydrogeomorphic literature, limited by methods and complexity of application. This thesis investigates the influence of biogenic variables on …
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Bedload transport: the effects of particle shape and an investigation of a wide range of transport rates
The effects of particle shape on bedload transport and a wide range of bedload transport rates using both bed subsurface and surface layer based approaches are investigated using fractional transport analysis with a similarity approach. Bedload transport data from a stream containing flat, low …
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Establishing an unambiguous connection between grain size and style of sediment transport in the Lower Niobrara River, Nebraska, USA
… sediment is often separated into two components, bedload and suspended load. This division is important because bedload has a dominant control on channel morphology while suspended load dominates the formation of overbank deposits. Experimental data has related the style of sediment transport to …
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Particle motion in the near bed region of a turbulent open channel flow: Implications for bedload transport by saltation and sediment entrainment into suspension
… simulate statistics of this process. Modelling bedload transport using results of the saltation model and a Bagnoldean formulation reveals problems with such formulation, particularly regarding the continuum hypothesis for the bedload layer. Results of the random walk model for particle …
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Quantitative geomorphology and hydrology of the Cass River Basin, New Zealand
… types of channels occur in the basin: confined bedload channels, unconfined bedload channels, and suspended-load channels. The confined and unconfined bedload channels are adjusted to transport a maximum of bedload sediment. The width of the confined bedload channels is limited by independent …
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Suspended sediment erosion in laboratory flume experiments
… channel. Experiments were run separately with bedload (used to form topography) and suspended load at a variety of water flows and sediment fluxes. Sediment samples were collected to determine mass flux and concentration profiles. Erosion was measured between each timestep and erosion rate …
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The effect of fluid acceleration on sediment transport in the surf zone
… different transport mechanisms are considered: bedload transport and "subsurface" transport. The potential for subsurface transport was first realized by Madsen (1974) who found that the large pressure gradient beneath a breaking wave was sufficient to drive a substantial porous-media flow, …
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SAMPLING AND MODELING OF SEDIMENT TRANSPORT AND RESERVOIR EROSION FOLLOWING DAM REMOVAL: MILLTOWN DAM, MONTANA
Measurements of bedload transport in combination with suspended sediment and discharge data collected by the USGS illustrate the rates, magnitudes and processes by which reservoir sediment evacuated the Milltown Reservoir after the 2008 removal of Milltown Dam from just downstream of the confluence …
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SAMPLING AND MODELING OF SEDIMENT TRANSPORT AND RESERVOIR EROSION FOLLOWING DAM REMOVAL: MILLTOWN DAM, MONTANA
Measurements of bedload transport in combination with suspended sediment and discharge data collected by the USGS illustrate the rates, magnitudes and processes by which reservoir sediment evacuated the Milltown Reservoir after the 2008 removal of Milltown Dam from just downstream of the confluence …
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Some effects of abandoned manganese strip mines in Smyth County, Virginia on stream ecology
… is probably the main contributing factor. Bedload was much greater in affected streams than in control streams. Although volume of bedload was high in Blue Spring Creek, which drains a reclaimed area, particle size distribution of the bedload indicates that much of the finest silt has been …
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Turbulence and macro-turbulence in the bottom boundary layer downstream of large-scale bedforms; implications for sediment transport
… macro-scale features of low flow speed, and the bedload transport, generating more frequent and larger bedload movements during macro-scale features of high flow speeds. These particularities result from variations in the turbulent bursting process within the macroturbulence structures. Ejection …
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