Observations of Bedform Migration and Bedload Sediment Transport in Combined Wave-Current Flows
Autor: | Meagan Wengrove, Thomas C. Lippmann, M.A. de Schipper, D. L. Foster, Joseph Calantoni |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
energetics
Bedform 010504 meteorology & atmospheric sciences Energetics surf zone Flow type bedload transport Surf zone Oceanography 01 natural sciences Flow field sediment transport Geophysics Space and Planetary Science Geochemistry and Petrology Earth and Planetary Sciences (miscellaneous) bedforms Geomorphology Sediment transport Geology 0105 earth and related environmental sciences Bed load combined waves and currents |
Zdroj: | Journal Of Geophysical Research-Oceans, 124(7) |
ISSN: | 2169-9275 |
Popis: | Bedload transport is an important mechanism for sediment flux in the nearshore. Yet few studies examine the relationship between bedform evolution and net sediment transport. Our work contributes concurrent observations of bedform mobility and bedload transport in response to wave dominant, current dominant, and combined wave-current flows in the nearshore. Bedload sediment flux from migrating bedforms during combined wave-current conditions accounted for at least 20% more bedload transport when compared with wave dominant flows and at least 80% more than current-dominant flows. Bedforms were observed to transport the most sediment during periods with strong currents, with high-energy skewed waves, and while bedform orientation and transport direction were aligned. Regardless of flow type, bedform migration rates were directly proportional to the total kinetic energy contained in the flow field. Eleven bedload transport models formulated to be used in combined flows (both shear and energetics based) were compared with sediment flux estimated from measured bedform migration. An energetics based sediment transport model was most representative for our data. |
Databáze: | OpenAIRE |
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