DETAILED SHORELINE MODELLING OF NARROWNECK ARTIFICIAL REEF, QUEENSLAND, AUSTRALIA

Kasper Kaergaard, Simon Mortensen, Rolf Deigaard, Darrell Strauss, Shannon Hunt

Abstract


The MIKE 21 FM Shoreline Model was applied to predict the coastal response of an artificial reef constructed in the surf-zone at Narrowneck, Queensland, Australia. The construction of the reef began in 1999 and completed in 2000; it was constructed from geotextile sand bag; a portion of which broke during construction and the following period. The reef was maintained by addition of new sand bags until 2006. The coastal response from the reef was analyzed by integrating the beach volume between the height of the dune and the depth of closure using measured coastal profiles. The analysis showed that in the early days of the reef a clear salient in the beach volume was observed in the lee of the reef. This salient was smaller in 2006 and in later years, 2012 and 2013 it was no longer visible in the data. The MIKE 21 FM shoreline model was applied to reproduce the observed coastal response. It was found that the position of the longshore bar relative to the position of the reef is important for the predicted coastal response. By running the model using a subset of the measured coastal profiles from the site, the envelope of the predicted coastal response matches reasonably well with the measured response.

Keywords


submerged structure; hybrid shoreline model; MIKE 21 FM; artificial reef; coastal response

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References


MIKE Powered by DHI (2016a). MIKE 21 FM ST, Sand Transport Module, User Guide.

Kaergaard, K., Fredsoe, J. 2013. A numerical shoreline model for shoreline with large curvature, Coastal Engineering, 74:19-32

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Ranasinghe and Turner (2006). Shoreline response to submerged structures: A review. Coastal Engineering, 53:65-79

Ruessink, G, Price, T and Castelle, B. 2013. Finite amplitude behaviour of alongshore variability in nearshore sand bars: Observations and modelling. Coastal Dynamics 2013 Arcachon, France




DOI: https://doi.org/10.9753/icce.v35.sediment.33