From Australian Oceans Data Network
JSON format icon JSON RDF format icon RDF ISO19115-3 XML

Beach Face and Berm Morphodynamics Fronting a Coastal Lagoon

Created 23/06/2025

Updated 23/06/2025

JSON format icon JSON RDF format icon RDF ISO19115-3 XML

This study documents two different modes of berm development: (1) vertical growth at spring tides or following significant beach cut due to substantial swash overtopping, and (2) horizontal progradation at neap tides through the formation of a proto-berm located lower and further seaward of the principal berm. Concurrent high-frequency measurements of bed elevation and the associated wave runup distribution reveal the details of each of these berm growth modes. In mode 1 sediment is eroded from the inner surf and lower swash zone where swash interactions are prevalent. The net transport of this sediment is landward only, resulting in accretion onto the upper beach face and over the berm crest. The final outcome is a steepening of the beach face gradient, a change in the profile shape towards concave and rapid vertical and horizontal growth of the berm. In mode 2 sediment is eroded from the lower two-thirds of the active swash zone during the rising tide and is transported both landward and seaward. On the falling tide sediment is eroded from the inner surf and transported landward to backfill the zone eroded on the rising tide. The net result is relatively slow steepening of the beach face, a change of the profile shape towards convex, and horizontal progradation through the formation of a neap berm. The primary factor determining which mode of berm growth occurs is the presence or absence of swash overtopping at the time of sediment accumulation on the beach face. This depends on the current phase of the spring-neap tide cycle, the wave runup height (and indirectly offshore wave conditions) and the height of the pre-existing berm. A conceptual model for berm morphodynamics is presented, based on sediment transport shape functions measured during the two modes of berm growth.

Files and APIs

Tags

Additional Info

Field Value
Title Beach Face and Berm Morphodynamics Fronting a Coastal Lagoon
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/7408604c-1df3-42ce-a50f-11c07d2d0380
Contact Point
Australian Ocean Data Network
michael.hughes@sydney.edu.au
Reference Period 13/10/2003 - 18/11/2004
Geospatial Coverage
Map data © OpenStreetMap contributors
{
  "coordinates": [
    [
      [
        151.437,
        -33.47
      ],
      [
        151.441,
        -33.47
      ],
      [
        151.441,
        -33.457
      ],
      [
        151.437,
        -33.457
      ],
      [
        151.437,
        -33.47
      ]
    ]
  ],
  "type": "Polygon"
}
Data Portal Australian Oceans Data Network

Data Source

This dataset was originally found on Australian Oceans Data Network "Beach Face and Berm Morphodynamics Fronting a Coastal Lagoon". Please visit the source to access the original metadata of the dataset:
https://catalogue.aodn.org.au/geonetwork/srv/eng/csw/dataset/beach-face-and-berm-morphodynamics-fronting-a-coastal-lagoon