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A numerical model of coastal overwash

Donnelly, Chantal LU ; Hanson, Hans LU and Larson, Magnus LU (2009) In Proceedings of the Institution of Civil Engineers. Maritime Engineering 162(3). p.105-114
Abstract
Overwash, the flow of water and sediment over the crest of a beach, contributes to flooding and the deposition of sand landward of the beach crest. Washover, the sand deposited by overwash, contributes to the sediment budget and migration of barrier islands. The ability to predict the occurrence, location, and thickness of overwash deposits is important for coastal residents, coastal town planners, environmental planners, and engineers alike. In this study, a numerical model that simulates the sediment transport and one-dimensional barrier profile change caused by overwash was developed. The magnitude of overwash and the morphology of washovers are dependent on the overwash regime. New formulae are developed to estimate the sediment... (More)
Overwash, the flow of water and sediment over the crest of a beach, contributes to flooding and the deposition of sand landward of the beach crest. Washover, the sand deposited by overwash, contributes to the sediment budget and migration of barrier islands. The ability to predict the occurrence, location, and thickness of overwash deposits is important for coastal residents, coastal town planners, environmental planners, and engineers alike. In this study, a numerical model that simulates the sediment transport and one-dimensional barrier profile change caused by overwash was developed. The magnitude of overwash and the morphology of washovers are dependent on the overwash regime. New formulae are developed to estimate the sediment transport rate over the beach crest for both run-up overwash, using ballistics theory, and inundation overwash, treating flow over the crest as weir flow. Two-dimensional flow is described on the back barrier by considering the continuity of a block of water at steady state, taking into account lateral spreading, friction, and infiltration. The model is tested against 26 different beach profile sets from several different locations, and several different storms, exhibiting a variety of initial morphologies. The model is capable of reproducing varying overwash morphology responses including dune crest erosion, dune destruction, barrier rollback, the thinning of a washover deposit on the backbarrier, and overwash over a multiple dune system. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
coastal engineering, hydraulics, hydrodynamics
in
Proceedings of the Institution of Civil Engineers. Maritime Engineering
volume
162
issue
3
pages
105 - 114
publisher
ICE UK
external identifiers
  • WOS:000272396400003
  • Scopus:77949571288
ISSN
1741-7597
DOI
10.1680/maen.2009.162.3.105
language
English
LU publication?
yes
id
cf535131-dc80-4c20-8dab-8cf15217224e (old id 769790)
date added to LUP
2008-01-18 07:02:35
date last changed
2016-10-13 04:35:38
@misc{cf535131-dc80-4c20-8dab-8cf15217224e,
  abstract     = {Overwash, the flow of water and sediment over the crest of a beach, contributes to flooding and the deposition of sand landward of the beach crest. Washover, the sand deposited by overwash, contributes to the sediment budget and migration of barrier islands. The ability to predict the occurrence, location, and thickness of overwash deposits is important for coastal residents, coastal town planners, environmental planners, and engineers alike. In this study, a numerical model that simulates the sediment transport and one-dimensional barrier profile change caused by overwash was developed. The magnitude of overwash and the morphology of washovers are dependent on the overwash regime. New formulae are developed to estimate the sediment transport rate over the beach crest for both run-up overwash, using ballistics theory, and inundation overwash, treating flow over the crest as weir flow. Two-dimensional flow is described on the back barrier by considering the continuity of a block of water at steady state, taking into account lateral spreading, friction, and infiltration. The model is tested against 26 different beach profile sets from several different locations, and several different storms, exhibiting a variety of initial morphologies. The model is capable of reproducing varying overwash morphology responses including dune crest erosion, dune destruction, barrier rollback, the thinning of a washover deposit on the backbarrier, and overwash over a multiple dune system.},
  author       = {Donnelly, Chantal and Hanson, Hans and Larson, Magnus},
  issn         = {1741-7597},
  keyword      = {coastal engineering,hydraulics,hydrodynamics},
  language     = {eng},
  number       = {3},
  pages        = {105--114},
  publisher    = {ARRAY(0x97540d0)},
  series       = {Proceedings of the Institution of Civil Engineers. Maritime Engineering},
  title        = {A numerical model of coastal overwash},
  url          = {http://dx.doi.org/10.1680/maen.2009.162.3.105},
  volume       = {162},
  year         = {2009},
}