Accelerated numerical simulation to investigate morphology changes around small tidal inlets

ABSTRACT

Among the state-of-the-art methods to study coastal processes using numerical modeling, input reduction techniques are advantageous with a significant reduction of required resources, particularly when conducting long-term simulations. This paper evaluates the suitability of these techniques to perform an accelerated morphological simulation, using a Delft3D coupled wave-hydrodynamic-sediment transport model for a small, jettied tidal inlet system (Currumbin Creek, Australia). Three different wave data reduction techniques were applied, namely categorized wave cases (CWC), synthetic wave events (SWE), and seasonally averaged wave events (SAWE). The results were compared with each other and a benchmark study – in particular, the required annual entrance dredging (equivalent to infilling) volume. The CWC, SWE and SAWE methods resulted in about +7%, – 8% and +1% larger infilling volume than the benchmark study, respectively. SAWE was found to be the fastest of all. However, in contrast to the SWE method, no intermediate results would be achieved using the CWC or SAWE methods and only the final pattern of sedimentation or the final volume of channel infilling can correctly be obtained.

KEYWORDS:

• Tidal inlet
• model schematization
• input reduction
• Delft3D
• numerical simulation

Acknowledgments

The first author acknowledges Griffith Centre for Coastal Management (GCCM) and Griffith University, Australia for support in performing this study. The first author also thanks Ms. Robynne Barnes and Mr. Mark Filmer for their help in enhancing the manuscript. The third author was supported by an Advance Queensland Research Fellowship in partnership with the City of Gold Coast and Griffith University. The access to data and partial funding provided by the City of Gold Coast is also acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Griffith University; Griffith Center for Coastal Management; Advance Queensland Research Fellowship; City of Gold Coast.