Observations on decadal sandbar behaviour along a large-scale curved shoreline

Autor: Gijsman, R., Ruessink, Gerben, Visscher, J., Schlurmann, T., Proceskunde, Coastal dynamics, Fluvial systems and Global change
Přispěvatelé: Proceskunde, Coastal dynamics, Fluvial systems and Global change, Marine and Fluvial Systems
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Length scale
Dewey Decimal Classification::900 | Geschichte und Geografie::910 | Geografie
Reisen
Geography
Planning and Development
Sandy shoreline
UT-Hybrid-D
Spatial and temporal scale
coastal profiles
periodicity
Low tide terraces
Germany
Earth and Planetary Sciences (miscellaneous)
Temporal scales
alongshore variability
Earth-Surface Processes
ddc:910
Shore
Planning and Development
geography
Landforms
geography.geographical_feature_category
Geography
coastal morphology
Earth surface process
curved coastlines
sandbar–shoreline coupling
Lead (sea ice)
Spatial scale
surf zone
sandbar
Shoal
Planform
Coastal engineering
Sylt
Phase coupling
shoreline
Oceanography
nearshore environment
Terrace (geology)
Geometric difference
nearshore sandbars
Wave climates
Scale (map)
nearshore morphology
Schleswig-Holstein
Geology
North Frisian Islands
Zdroj: Earth Surface Processes and Landforms 46 (2021), Nr. 2
Earth Surface Processes and Landforms
Earth surface processes and landforms, 46(2), 490-503. Wiley
Earth Surface Processes and Landforms, 46(2), 490. Wiley Online Library
ISSN: 0197-9337
Popis: Nearshore sandbars are characteristic features of sandy surf zones and have been observed with a variety of geometries in cross-shore (e.g. location) and longshore direction (e.g. planform). Although the behaviour of sandbars has been studied extensively on spatial scales up to kilometres and timescales up to years, it remains challenging to observe and explain their behaviour on larger spatial and temporal scales, especially in locations where coastline curvature can be prominent. In this paper, we study a data set with 38 years of coastal profiles, collected with alongshore intervals of 50 m, along the 34 km-long curved sandy shoreline of Sylt island, Germany. Sylt's shoreline has an orientation difference of ~20° between the northern and southern half of the island. We found that the decadal coastal profiles on the southern half show features of a low-tide terrace and a sandbar located further from the shoreline (~441 m). On the nothern half, the sandbar was located closer to the shoreline (~267 m) and was less pronounced, while the profiles show transverse bar and rip features. The alongshore planform also differed systematically and significantly along the two island sides. The sandbar on the southern island half, with alongshore periodicity on a larger length scale (~2240 m), was coupled out-of-phase to the shoreline, while no phase coupling was observed for the sandbar with periodicity on a shorter length scale (~670 m) on the northern half. We related the observed geometric differences of the sandbars to the difference in the local wave climate along Sylt, imposed by the shoreline shape. Our observations imply that small alongshore variations in wave climate, due to the increasing shoreline curvature on larger spatial scales, can lead to significant alongshore differences in the decadal evolution of coastal profiles, sandbars and shorelines. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd. © 2020 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd
Databáze: OpenAIRE
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