Finite amplitude sand waves in shallow seas : modelling of spatial and temporal variations in offshorre sandwaves [Powerpoint Presentation]

Attila Nemeth

    Research output: Contribution to conferencePaperAcademic

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    Abstract

    Sand waves form a prominent regular pattern in the offshore seabeds of sandy shallow seas. A two dimensional vertical (2DV) flow and morphological simulation model describing the behaviour of these sand waves has been developed. The model contains the 2DV shallow water equations, with a free water surface and a general bed load formula. The water movement is coupled to the sediment transport equation with a seabed evolution equation. The spatial discretisation is performed by a spectral method based on Chebyshev polynomials. A fully implicit method is chosen for the discretisation in time. With this model we investigate the intermediate term behaviour of an observed sand wave field of the Dutch coast. Firstly, a stability analysis is performed to determine the initially most preferred modes. Secondly, the numerical simulation model is used to investigate the properties of the system during the evolution of the sand waves. Hereby, we find sand wave saturation for a height of about 10-30% of the water depth with an average time scale of about 15 years. The sand waves become asymmetrical in the vertical. The order of magnitudes found of the time and spatial scales coincide with the observations.
    Original languageUndefined
    Number of pages16
    Publication statusPublished - 2004
    EventNCK-dagen 2004 - Yerseke, The Netherlands, Yerseke, Netherlands
    Duration: 18 Mar 200419 Mar 2004

    Conference

    ConferenceNCK-dagen 2004
    CountryNetherlands
    CityYerseke
    Period18/03/0419/03/04
    Other18 en 19 maart 2004

    Keywords

    • IR-60426

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