Observations of the swash zone on a gravel beach during a storm using a laser-scanner (Lidar)

• Published in: Journal of coastal research Vol. 1; no. 65; p. 636
• Main Authors: Almeida, Luis Pedro, Masselink, Gerd, Russell, Paul, Davidson, Mark, Poate, Tim, McCall, Robert, Blenkinsopp, Chris, Turner, Ian
• Format: Journal Article
• Language: English
• Published: Fort Lauderdale Allen Press Inc 01.01.2013
• Subjects: Beaches; Coastal; Coasts; Feedback; Gravel; Instrumentation; Measurement; Morphology; Sand & gravel; State of the art; Storms
• ISSN: 0749-0208; 1551-5036
• DOI: 10.2112/SI65-108

The collection of detailed field measurements from the swash zone during storms is an extremely challenging task which is difficult to execute with traditional in-situ deployments. The levels of difficulty increase for gravel beaches where the wave energy reaches the beach face with almost no loss of energy, leading to violent plunging wave breaking on the beach face that can produce large vertical morphological changes and extremely strong uprushes that can easily and rapidly damage, bury or detach instrumentation. Remote-sensing techniques emerge as the most appropriate solution to perform field measurements under such adverse conditions since they have the ability to perform measurements without being deployed in-situ. The results from the comparison of this system with other state-of-the-art instruments indicate that the quality of the measurements obtained is within the accuracy of the standard methods. Measurements performed with a laser-scanner on a gravel beach show complex and fast-changing morphology on the gravel beach, which appears to be a form of negative morphodynamic feedback to controls the hydrodynamic evolution in the swash zone.