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| Titel |
The investigation of the formation of river delta deposits is an important subject in geomorphology. Recently a reduced complexity model which simulates the process of delta formation on geological time scales has been proposed Modeling River Delta Format |
| VerfasserIn |
H. Seybold, P. Molnar, J. S. Andrade, W. Kinzelbach, H. J. Herrmann |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026635
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| Zusammenfassung |
| The investigation of the formation of river delta deposits is an important
subject in geomorphology. Recently a reduced complexity model which simulates
the process of delta formation on geological time scales has recently been proposed
by the authors. It includes subaerial and subaqueous growth in a three
dimensional framework. In this paper we investigate details of the modelled
dynamics applied to a river-dominated delta and compare them with observations
of the formation of the Balize Lobe of the Mississippi River Delta. We show that
the dimensionless parameters of the model may be rescaled to match the size of
the delta, the lobe volume, observations of water and sediment inflows, and the
duration of lobe formation. We show that the model is internally consistent from
the process point of view and gives physically meaningful results. The
erosion-deposition law generates both subaerial and subaqueous channel and
lateral levee formations which are similar to natural ones. Finally we use
detrended fluctuation analysis to show that the model produces long-term
simulated dynamics of the delta formation process with a complex temporal
correlation structure. A characteristic timescale separates periods of
consistent delta growth by gradual sediment deposition at the mouths of
distributary channels from periods at which random large scale channel avulsions
lead to rapid change and the formation of new channels and subaqueous dominated
deposition. |
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