Geologically controlled sandy beaches: Their geomorphology, morphodynamics and classification.

Autor: Gallop SL; School of Science, University of Waikato, Tauranga 3110, New Zealand; Environmental Research Institute, University of Waikato, Hamilton 3240, New Zealand. Electronic address: shari.gallop@waikato.ac.nz., Kennedy DM; School of Geography, The University of Melbourne, Parkville 3010, VIC, Australia. Electronic address: davidmk@unimelb.edu.au., Loureiro C; Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom; Geological Sciences, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa. Electronic address: carlos.loureiro@stir.ac.uk., Naylor LA; School of Geographical and Earth Sciences, University of Glasgow, G12 8QQ, United Kingdom. Electronic address: Larissa.Naylor@glasgow.ac.uk., Muñoz-Pérez JJ; CASEM (Andalusian Centre for Maritime Studies), Universidad de Cadiz, 11510 Puerto Real, Spain. Electronic address: juanjose.munoz@uca.es., Jackson DWT; School of Geography and Environmental Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, United Kingdom. Electronic address: d.jackson@ulster.ac.uk., Fellowes TE; Department of Earth and Environmental Sciences, Macquarie University, 2109, NSW, Australia; Geocoastal Research Group, School of Geosciences, The University of Sydney, 2006, NSW, Australia. Electronic address: thomas.fellowes@sydney.edu.au.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2020 Aug 20; Vol. 731, pp. 139123. Date of Electronic Publication: 2020 May 04.
DOI: 10.1016/j.scitotenv.2020.139123
Abstrakt: Beaches that are geologically controlled by rock and coral formations are the rule, not the exception. This paper reviews the current understanding of geologically controlled beaches, bringing together a range of terminologies (including embayed beaches, shore platform beaches, relict beaches, and perched beaches, among others) and processes, with the aim of exploring the multiple ways in which geology influences beach morphology and morphodynamics. We show how in addition to sediment supply, the basement geology influences where beaches will form by providing accommodation, and in the cross-shore, aspects of rock platform morphology such as elevation and slope are also important. Geologically controlled beaches can have significant variations in sediment coverage with seasons and storms, and geological controls have fundamental influences on their contemporary morphodynamics. This includes wave shadowing by headlands and rock/coral formations inducing strong alongshore gradients in wave energy, resulting in corresponding variations in morphodynamic beach state and storm response. Geologically-induced rip currents including shadow rips, deflection rips and mega-rips that can develop on embayed beaches during storms, are an integral feature of the nearshore circulation and morphodynamics of geologically controlled beaches. We bring these processes together by presenting a conceptual model of alongshore and cross-shore levels of geological control. In the longshore dimension, this ranges from beaches that are slightly embayed, through to highly embayed beaches where headlands dominate the entire beach morphodynamic response. In the cross-shore dimension, this ranges from beaches without discernible geological controls, through to relict beaches above the influence of the contemporary littoral zone. Given the prevalence of geologically controlled beaches along the world's coasts, it is paramount for coastal management to consider how these beaches differ from unconstrained beaches and avoid applying inappropriate models and tools, especially with our uncertain future climate.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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