Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model
The non-hydrostatic wave-flow model SWASH was used to investigate the hydrodynamic processes at a reef fringed pocket beach in southwestern Australia (Gnarabup Beach). Gnarabup Beach is a ~1.5 km long beach with highly variable bathymetry that is bounded by rocky headlands. The site is also exposed...
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ftmdpi:oai:mdpi.com:/2077-1312/8/11/877/ 2023-08-20T04:09:58+02:00 Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model Johan Risandi Dirk P. Rijnsdorp Jeff E. Hansen Ryan J. Lowe agris 2020-11-04 application/pdf https://doi.org/10.3390/jmse8110877 EN eng Multidisciplinary Digital Publishing Institute Coastal Engineering https://dx.doi.org/10.3390/jmse8110877 https://creativecommons.org/licenses/by/4.0/ Journal of Marine Science and Engineering; Volume 8; Issue 11; Pages: 877 fringing reef pocket beach hydrodynamics SWASH Western Australia Text 2020 ftmdpi https://doi.org/10.3390/jmse8110877 2023-08-01T00:24:26Z The non-hydrostatic wave-flow model SWASH was used to investigate the hydrodynamic processes at a reef fringed pocket beach in southwestern Australia (Gnarabup Beach). Gnarabup Beach is a ~1.5 km long beach with highly variable bathymetry that is bounded by rocky headlands. The site is also exposed to large waves from the Southern Ocean. The model performance was evaluated using observations collected during a field program measuring waves, currents and water levels between June and July 2017. Modeled sea-swell wave heights (periods 5–25 s), infragravity wave heights (periods 25–600 s), and wave-induced setup exhibited moderate to good agreement with the observations throughout the model domain. The mean currents, which were highly-spatially variable across the study site, were less accurately predicted at most sites. Model agreement with the observations tended to be the worst in the areas with the most uncertain bathymetry (i.e., areas where high resolution survey data was not available). The nearshore sea-swell wave heights, infragravity wave heights and setup were strongly modulated by the offshore waves. The headlands and offshore reefs also had a strong impact on the hydrodynamics within the lagoon (bordered by the reefs) by dissipating much of the offshore sea-swell wave energy and modifying the pattern of the nearshore flows (magnitude and direction). Wave breaking on the reef platforms drove strong onshore directed mean currents over the reefs, resulting in off-shore flow through channels between the reefs and headlands where water exchanges from the lagoon to ocean. Our results demonstrate that the SWASH model is able to produce realistic predictions of the hydrodynamic processes within bathymetrically-complex nearshore systems. Text Southern Ocean MDPI Open Access Publishing Southern Ocean Long Beach Swash ENVELOPE(-67.524,-67.524,-67.581,-67.581) Journal of Marine Science and Engineering 8 11 877 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
fringing reef pocket beach hydrodynamics SWASH Western Australia |
spellingShingle |
fringing reef pocket beach hydrodynamics SWASH Western Australia Johan Risandi Dirk P. Rijnsdorp Jeff E. Hansen Ryan J. Lowe Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model |
topic_facet |
fringing reef pocket beach hydrodynamics SWASH Western Australia |
description |
The non-hydrostatic wave-flow model SWASH was used to investigate the hydrodynamic processes at a reef fringed pocket beach in southwestern Australia (Gnarabup Beach). Gnarabup Beach is a ~1.5 km long beach with highly variable bathymetry that is bounded by rocky headlands. The site is also exposed to large waves from the Southern Ocean. The model performance was evaluated using observations collected during a field program measuring waves, currents and water levels between June and July 2017. Modeled sea-swell wave heights (periods 5–25 s), infragravity wave heights (periods 25–600 s), and wave-induced setup exhibited moderate to good agreement with the observations throughout the model domain. The mean currents, which were highly-spatially variable across the study site, were less accurately predicted at most sites. Model agreement with the observations tended to be the worst in the areas with the most uncertain bathymetry (i.e., areas where high resolution survey data was not available). The nearshore sea-swell wave heights, infragravity wave heights and setup were strongly modulated by the offshore waves. The headlands and offshore reefs also had a strong impact on the hydrodynamics within the lagoon (bordered by the reefs) by dissipating much of the offshore sea-swell wave energy and modifying the pattern of the nearshore flows (magnitude and direction). Wave breaking on the reef platforms drove strong onshore directed mean currents over the reefs, resulting in off-shore flow through channels between the reefs and headlands where water exchanges from the lagoon to ocean. Our results demonstrate that the SWASH model is able to produce realistic predictions of the hydrodynamic processes within bathymetrically-complex nearshore systems. |
format |
Text |
author |
Johan Risandi Dirk P. Rijnsdorp Jeff E. Hansen Ryan J. Lowe |
author_facet |
Johan Risandi Dirk P. Rijnsdorp Jeff E. Hansen Ryan J. Lowe |
author_sort |
Johan Risandi |
title |
Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model |
title_short |
Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model |
title_full |
Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model |
title_fullStr |
Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model |
title_full_unstemmed |
Hydrodynamic Modeling of a Reef-Fringed Pocket Beach Using a Phase-Resolved Non-Hydrostatic Model |
title_sort |
hydrodynamic modeling of a reef-fringed pocket beach using a phase-resolved non-hydrostatic model |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2020 |
url |
https://doi.org/10.3390/jmse8110877 |
op_coverage |
agris |
long_lat |
ENVELOPE(-67.524,-67.524,-67.581,-67.581) |
geographic |
Southern Ocean Long Beach Swash |
geographic_facet |
Southern Ocean Long Beach Swash |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Journal of Marine Science and Engineering; Volume 8; Issue 11; Pages: 877 |
op_relation |
Coastal Engineering https://dx.doi.org/10.3390/jmse8110877 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/jmse8110877 |
container_title |
Journal of Marine Science and Engineering |
container_volume |
8 |
container_issue |
11 |
container_start_page |
877 |
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1774723777756659712 |