Print Email Facebook Twitter A novel approach to mapping ebb-tidal delta morphodynamics and stratigraphy Title A novel approach to mapping ebb-tidal delta morphodynamics and stratigraphy Author Pearson, S.G. (TU Delft Environmental Fluid Mechanics) Elias, Edwin (Deltares) van Prooijen, Bram (TU Delft Environmental Fluid Mechanics) van der Vegt, H. (Deltares) van der Spek, A.J.F. (TU Delft Coastal Engineering; Deltares; Universiteit Utrecht) Wang, Zhengbing (TU Delft Coastal Engineering) Date 2022 Abstract Ebb tidal deltas (ETDs) are highly dynamic features of sandy coastal systems, and coastal management concerns (e.g., nourishment and navigation) present a pressing need to better describe and quantify their evolution. Here we propose two techniques for leveraging the availability of high-resolution bathymetric surveys to generate new insights into the dynamics and preservation potential of ebb-tidal deltas. The first technique is conformal mapping to polar coordinates, using Ameland ebb-tidal delta in the Netherlands as a case study. Since the delta tends to evolve in a clockwise direction around the inlet, this approach provides an improved quantification and visualization of the morphodynamic behaviour as a timestack. We clearly illustrate the sediment bypassing process and repeated rotational migration of channels and shoals across the inlet from updrift to downdrift coasts. Secondly, we generate a decadal scale (1975–2021) stratigraphic model from the differences between successive bathymetries. This stratigraphy showcases the delta's depositional behaviour through space and time, and provides a modern analogue for prehistoric ebb-tidal deltas. During the surveyed period, inlet fills form the largest and most stable deposits, while the downdrift swash platform is the most stable structure over longer periods. Together, these approaches provide new perspectives on ebb-tidal delta dynamics and preservation potential which are readily applicable to other sites with detailed bathymetric data. These findings are valuable at annual to decadal timescales for coastal management (e.g., for planning sand nourishments) and also at much longer timescales for interpreting stratigraphy in ancient rock records. To reference this document use: http://resolver.tudelft.nl/uuid:d8e7bd9f-a072-477e-8c9d-5a5c9f072011 DOI https://doi.org/10.1016/j.geomorph.2022.108185 ISSN 0169-555X Source Geomorphology, 405 Part of collection Institutional Repository Document type journal article Rights © 2022 S.G. Pearson, Edwin Elias, Bram van Prooijen, H. van der Vegt, A.J.F. van der Spek, Zhengbing Wang Files PDF Pearson2022_A_novel_appro ... graphy.pdf 11.04 MB Close viewer /islandora/object/uuid:d8e7bd9f-a072-477e-8c9d-5a5c9f072011/datastream/OBJ/view