University of Twente Proceedings
Modeling plan-form deltaic response to changes in fluvial sediment supply
Nienhuis, J.H. and Ashton, A.D. and Roos, P.C. and Hulscher, S.J.M.H. and Giosan, L. (2012) Modeling plan-form deltaic response to changes in fluvial sediment supply. In: NCK-days 2012 : Crossing borders in coastal research., 13 March 2012 - 16 March 2012, Enschede, the Netherlands .
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Event: | NCK-days 2012 : Crossing borders in coastal research., 13 March 2012 - 16 March 2012, Enschede, the Netherlands |
Abstract: | This study focuses on the effects of changes in fluvial sediment supply on the plan-form shape of wave-dominated deltas. We apply a one-line numerical shoreline model to calculate shoreline evolution after (I) elimination and (II) time-periodic variation of fluvial input. Model results suggest four characteristic modes of wave-dominated delta development after abandonment. The abandonment mode is determined by the pre-abandonment downdrift shoreline characteristics and wave climate (which are, in turn, determined by previous delta evolution). For asymmetrical deltas experiencing shoreline instability on the downdrift flank, time-periodic variation in fluvial input influences the evolution of downdrift-migrating sandwaves. The frequency and magnitude of the riverine "forcing" can initiate a pattern that migrates away from the river mouth, interacting with the development of shoreline sandwaves. Model results suggest that long-period signals in fluvial delivery can be shredded by autogenic sand waves, whereas shorter-term riverine fluctuations can dominate the signal of the autogenic sandwaves. The insights provided by these exploratory numerical experiments provide a set of hypotheses that can be further tested using natural examples. |
Item Type: | Conference or Workshop Item (Paper) |
Link to this item: | https://doi.org/10.3990/2.192 |
Organisation URL: | http://www.nck-web.org/ |
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