Random-Walk Suspended Sediment Transport and Settling Model

This paper describes a particle-based approach to simulate entrainment, transport, and settling of non-cohesive sediments in rivers and the coastal zone where the velocity distribution is characterized by a fully-developed turbulent boundary layer extending from the bed. Sediment distributions are modeled as a set of particles that are tracked on an individual basis by solving Lagrangian transport equations that account for advection by the mean flow, settling, and random turbulent motions. This vertical distribution of the mean flow is modeled by a power law, and turbulent motions are modeled as a random walk that is scaled by the turbulent diffusivity analogous to random molecular motions that constitute Fickian diffusion. Because it is not feasible to track individual sediment grains, each particle accounts for a large number of sediment grains of a single size and settling velocity. A suite of particles is used to account for a spectrum of grain sizes. A model resolves the vertical distribution of particles consistent with Rouse profiles for a wide range of Rouse numbers. Using a entrainment relationship from literature, model predictions of sediment loads compare favorably to established empirical models. The model is applied to predict the collection efficiency of a sedimentation basin in Ballona Creek, California, highlighting the effectiveness of the basin at collecting coarse sands but not finer grained material.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0784407347
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Argall, Richard
  • Sanders, Brett F
  • Poon, Ying-Keung
• Conference:
  • Estuarine and Coastal Modeling. Eighth International Conference
  • Location: Monterey California, United States
  • Date: 2003-11-3 to 2003-11-5
• Publication Date: 2004

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References;
• Pagination: pp 713-730
• Monograph Title: Estuarine and Coastal Modeling

Subject/Index Terms

• TRT Terms: Coastal engineering; Coastal zone management; Empirical methods; Particles; Randomization; Rivers; Sedimentation; Sediments; Suspended sediments; Turbulence; Walking
• Subject Areas: Data and Information Technology; Environment; Marine Transportation; Pedestrians and Bicyclists; Policy;

Filing Info

• Accession Number: 01005937
• Record Type: Publication
• ISBN: 0784407347
• Files: TRIS
• Created Date: Oct 21 2005 7:59AM