ESTIMATING LANDWARD MIGRATION OF NEARSHORE CONSTRUCTED SAND MOUNDS

A model for the migration of submerged mounds constructed offshore of the day-to-day surf zone but within the depths disturbed by waves during storm events is developed. The model considers net shorewards sand transport due to the velocity asymmetry of finite-amplitude waves, and is based on Bagnold's bed-load-sand transport equation with Stokes' second-order wave theory. Conservation of sand considerations lead to an equation that indicates mounds will behave according to a nonlinear convection- diffusion model. The "convection coefficient" -like parameter, which is based on the wave and sand-transport models only, is proposed as an estimate of the migration rage for submerged mounds. The expected value of mound movement in different depths can be estimated with site-specific wave-climate data. The full sediment- transport equations successfully simulate the migration of a mound at Silver Stand State Park, California, in 1989. The expected value of the mound-movement parameter gives results that agree reasonable well with measured migration rates at Silver Strand and offshore of Mobile, Alabama.

  • Supplemental Notes:
    • J Waterway, Port, Coastal, Ocean Engng, v 121 n 5, Sept/Oct 1995, p 247 [4 p, 10 ref, 2 fig]
  • Authors:
    • Douglass, S L
  • Publication Date: 1995

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00717641
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Mar 4 1996 12:00AM