The State of Art of Physical Modelling of Sediment Transport
The paper attempts formula some ideas about the state of the art in the field of physical modelling of sediment transport processes. Up to now the physics of sediment transport are not...
Potential Flow Over a Wavy Bed: A Persistent Error
The standard small-amplitude theory of potential flow over a wavy bed is briefly discussed, together with the three special values of the Froude Number which define four different flow...
Bed Waves Generated by Internal Waves in Alluvial Channels
The flow in an alluvial channel is conceived as a stratified flow both with respect to the velocity- and density-distribution. In such flows internal waves may occur which influence the...
Application of 2-D Model to Reduce Sedimentation Problems
The Corps of Engineers opened Lock and Dam No. 1 on the Red River Waterway in 1984. During the first runoff season, excessive quantities of fine sediment deposited in both the upstream...
Modelling of Sand Bars in Coastal Environments
A mathematical model describes the formation of sand bars by progressive wind-generated waves. The model decomposes into several constituents linked together in a two step morphological...
A Method to Treat Incident Wave Condition in Shallow Water Equation
A method to consider open boundary condition of the shallow water equation to analyze water surface wave and tide is employed in the finite element anaysis. This can be done by considering...
An Alternative Approach to Erosion Control and Mitigation
A case study is presented in which a sediment engineering investigation was conducted to determine the potential effects of a change in flow regulation on the channel downstream of a lake,...
Wave?Current Interaction and Sediment Transport
The paper reports on a study into whether a close relationship between the mixing (diffusion) coefficient for the sediment, ?s, and the mixing (diffusion)...
Using Sediment-Threshold Theories in Waves and Currents
Fundamentally different threshold-of-motion theories were applied to sand transport in two different coastal environments. Several recommendations for threshold application were reached....
Transport of Grain-Water Mixture by Waves
The numerical modelling of the morphological changes of coastal regions is hampered by the multiplicity of empirical sediment transport formulae. The paper discusses the modes of transport...
The Beginning of Sediment Transport as a Probability-Problem
Sediment transport only takes place when the action of flow (shear stress, velocity) exceeds a critical value. The limit between rest and movement can be given as critical flow velocity,...
Instability of Bed-Surface Composition Due to Sorting Process in a Stream Composed of Sand and Gravel
Wavy patterns of sorting are often observed in a stream composed of sand and gravel, and they are regarded as instability of bed-surface composition due to selective bed-load transport...
Mid-Scale Laboratory Tests on a Two-Dimensional Movable-Bed Sand Model
A two-dimensional physical model was used to simulate wave-induced scour in front of a concrete dike sloped at 1:4. The tests were conducted at the U.S. Army Engineers Waterways Experiment...
The Structure of Intermittent Sand Suspension Events Under Mild Wave Conditions
Nearshore sedimentation processes are being actively investigated through a series of research projects at the University of Miami. Quantitative measurements of waves, currents, and suspended...
The Effects of Velocity on Scour
Four effects of 'velocity' on scour are discussed: clear-water scour, scour by light sediment-transporting flow, mode of movement, and kinetic terms included...
Field Measurement of Topography at a River Mouth
The authors have been measuring topography and cross section at the river mouth of the Nanakita River, in Japan. Changes of short-time scale, such as straightening of the river channel...
Hyperconcentrations, Mud and Debris Flows?A Summary
Brief descriptions of the properties of mud and debris flow and hyperconcentrated stream flow materials and their importance to the descriptions and modeling of these flows are presented....
Flow Modeling in the Toutle River, Washington
In support of flow, suspended load, bed load, and bedform transport measurements, a quasi-three-dimensional river flow model was adapted to a reach extending from 260m upstream to 30m...
Alluvial Stream Bank Erosion?A 10-Year Study
Results of investigations of bank erosion along alluvial streams between 1977 and 1989 are given. Natural processes were found to dominate, with piping an important but hitherto unrecognized...
Bank Failure and Erosion on the Illinois Waterway
In 1988, bank failure and erosion on the Illinois Waterway were evaluated. Banks were inspected from the air and from a motor vessel; thirty-one sites were examined in detail. Severe erosion...
Return to search