Hydrodynamic Drivers and Morphological Responses on Small Coral Islands—The Thoondu Spit on Fuvahmulah, the Maldives

authored by: C.G. David, T. Schlurmann
Abstract: Assessing the resilience of islands toward altered ocean climate pressures and providing robust adaptation measures requires an understanding of the interaction between morphological processes and the underlying hydrodynamic drivers. In this sense, this study presents changing sediment volumes on various temporal scales for the fringing reef island Fuvahmulah. Based on three field campaigns, conducted over 2 years, aerial imagery provides information on marine aggregates of the island's beaches. In addition, high resolution climate reanalysis data serves as input into an empirical and a numerical approach. Together, both approaches describe the driving processes behind volumetric seasonal and interannual changes: On the one hand, the empirical method quantifies sediment transport rates for calcareous sediments over the whole time span of the data set by considering wind and swell waves from multiple directions. On the other hand, the numerical method gives insights into the complexity of currents induced by dominant wave components. Combining these methods facilitates hindcasting and predicting morphological changes under varying wave climate, assessing sediment pathways over the whole reef, and describing the seasonal and interannual evolution of the sand spit Thoondu. As a result, this study reveals sediment distribution on different spatio-temporal scales and elucidates their significance in the design of conventional and alternative low-regret coastal adaptation.
Organisation(s): Ludwig-Franzius-Institute of Hydraulics, Estuarine and Coastal Engineering
Type: Article
Journal: Frontiers in Marine Science
Volume: 7
ISSN: 2296-7745
Publication date: 29.10.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Water Science and Technology, Environmental Science (miscellaneous), Ocean Engineering, Aquatic Science, Oceanography, Global and Planetary Change
Sustainable Development Goals: SDG 13 - Climate Action, SDG 14 - Life Below Water
Electronic version(s): https://doi.org/10.3389/fmars.2020.538675 (Access: Open)