Flow Transitions Around a Single Large Bed Element
A qualitative description of the characteristics of supercritical-to-subcritical flow transitions due to the presence of a single large bed element (LBE) in a laboratory flume is presented....

Sediment and Aquatic Habitat Associations in River Systems
This paper results from the Task Committee's effort to summarize knowledge linking sediment transport and aquatic ecology. This paper presents one element of this work: the...

Sediment Transport, Hydraulic Retention Devices, and Aquatic Habitat in Sand-Bed Channels
Streams and rivers of all sizes and in all parts of the United States flow on sand-bed channels. Scour, Transport, and deposition of sediments particles are natural processes in these...

Sediment Transport and Aquatic Habitat in Gravel-Bed Rivers
Gravel-bed rivers experience dymanic conditions of flow and sediment transport. Long periods of bed stability are interrupted by shorter periods of bed mobility when major changes and...

On-Site Incineration
A variety of equipment is now available for incinerating hazardous wastes in situ. Thermal treatment, compared to land disposal, offers limited liability and immediate destruction. It...

The National PDES Testbed?An Overview
Product Data Exchange Specification (PDES) is an ambitious project with the goal of developing a standardized format for representing and exchanging information about almost any manufactured...

Performance Testing of Wide Area Networks
Institute for Telecommunication Sciences (ITS) has developed a software measurement system to support the ANSI standards X3.102 and X3.141. This system is being used to evaluate data communication...

Advances in Computational Mobile-Bed Hydraulics
A new conceptual approach to one-dimensional mobile-bed simulation is briefly described, along with two demonstrative examples. The approach is based on fully coupled solution of the unsteady...

Quasi-2D Transport and Morphological Forecasting in Large River Systems
Unused potentials of 1D morphological, and transport models were applied to predict not only the longitudinal but also the transverse distribution of concentrations and natural river bed...

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...

Modeling of Contaminant Transport in Rivers with Emphasis on the Interaction with Movable Boundaries
The transport of dissolved and absorbed pollutants is simulated by a one-dimensional convection-diffusion model which particularly accounts for the exchange processes at the river bed...

Channel Entrenchment Along the Post Creek Cutoff in Southern Illinois
The Post Creek Cutoff was constructed in 1915 by the Cache River Drainage Commission to divert flow from the Upper Cache River to the Ohio River. The construction of the cutoff reduced...

Towards a Distinct Treatment of Incipient Motion for Bed Forms of Low Regime
The principle methods for estimating the incipient particle motion on developed bed forms in the lower regime are compared with each other. Usually only a part of the total wall shear...

A Continuum Mechanics Approach to Loose-Bed Motion
A mathematical model is presented for simulation of loose-bed motion. The physical system is separated into two regions, a bottom region and an upper region. The bottom region is representative...

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...

Areal Sampling Techniques
Three areal methods, commonly used for sampling the coarser surface layer of gravel-bed streams, are examined. An idealized sediment deposit, that consists of cubic particles and accounts...

Sediment Transport in Hyperconcentrated Flows in Sand-Bed Streams
This study advances the understanding of sediment transport of bed material discharge in sand bed streams through application of recently developed theoretical concepts related to the...

The Area of Scour Hole Around Bridge Piers
The study is focused on what parameters determine the area of scour hole around bridge piers. An analytical study based on momentum principle has been used to reveal the variables involved...

Selective Erosion: A Key Problem in Numerical Modelling of River-bed Changes
In capacity-controlled sediment transport of alluvial rivers the so-called 'hiding factor' determines the stability of the various grain-size fractions. The paper...

On the Selection of Sediment Transport Equations
Certain aspects of the selection of equations to use in the calculation of sediment transport in streams are examined in this paper. The use of a critical discharge is examined and problems...

 

 

 

 

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