Author(s): Jeffrey S. Doucette
Linked Author(s):
Keywords: Shore platform; Platform beach; Beach evolution; Stereophotography
Abstract: Field observations were performed to investigate the processes of erosion and accretion on a platform beach at Cottesloe, Western Australia. The position of the shoreline was estimated from daily photographs taken from a fixed camera location. Process information was obtained from an offshore wave rider buoy, water level records from Fremantle Harbour, and a local meteorological station. Additional observations of beach morphology were made using a trial hand held stereophotographic technique. Seasonal patterns of erosion and accretion are identified and processes are described over a typical erosive storm event followed by beach recovery. As expected, erosion events correlate to high wave steepness and higher than average water levels. The threshold between erosion and accretion events is determined based on wave steepness and relative water level. Identification of this threshold is useful for modelling future evolution along this coast given predictions of potential climate change impacts such as increased storminess and/or increase in sea level. The simple methodology presented could be applied to other environments.
Year: 2009