RT journal article
T1 Multi-scale morphodynamics of an estuarine beach adjacent to a flood-tide delta: Assessing decadal scale erosion
A1 Harris, Harris
A1 Vila-Concejo, Ana
A1 Austin, Tim
A1 Benavente González, Javier
A2 Ciencias de la Tierra
K1 Australia
K1 beach
K1 coastal erosion
K1 decadal variation
K1 estuarine dynamics
K1 flood
K1 morphodynamics
K1 sediment transport
AB Estuarine beaches are ubiquitous, yet understudied, coastal systems. The mixed hydrodynamic processes – such as combined tidal and wave forcing – and the influence of adjacent sedimentary features – such as flood-tide deltas (FTDs) – leads to complex morphodynamic processes. As such, the dynamics and evolution of these important coastal systems are poorly understood. This study synthesises a set of analyses conducted on an estuarine beach, in southeast Australia, over multiple temporal scales. Nearshore waves and currents were measured and used to determine the processes driving seasonal to yearly beach change between 2007 and 2010. These results were compared to decadal scale beach change determined from aerial photos between 1963 and 2006. We found the westward transport of sediment towards the inner estuary was the dominant nearshore process leading to erosion in the eastern regions of the beach (near the estuary entrance) and accretion in the west over yearly time scales. Cross-shore sediment transport occurred during winter storm swell conditions leading to erosion in more exposed sites and some limited accretion in sheltered zones, most likely due to sediment input from the flood-tide delta. However, severe storm swell events that propagated into the estuary led to a loss of sediment and erosion across the entire beach which was not recovered during the study period. It is likely that the erosion processes observed in the short- to medium-term (days to years) analyses are the conditions that led to the long-term shoreline retreat observed in the aerial photograph record. The long-term shoreline retreat since 1963 is likely a result of a negative sediment balance due to movement of the FTD and a lack of sediment input in the eastern regions of Shoal Bay. Shoreline retreat will likely continue unless increased sediment input occurs from marine sources or shoreline interventions are maintained.
PB Elsevier
SN 0272-7714
YR 2020
FD 2020-08-31
LK http://hdl.handle.net/10498/34911
UL http://hdl.handle.net/10498/34911
LA eng
NO This research was funded by the Australian Research Council (ARC) in collaboration with the Office of Environment and Heritage (OEH), a division of the NSW Department of Premier and Cabinet (formerly the Department of Environment, Climate Change and Water (DECCW)), Great Lakes Council, Port Stephens Council and Jimmy’s Beach Restoration Society Inc. through Linkage Grant LP0668979.
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026