Now showing items 1-20 of 61

  • A field test of a linear stability model for crescentic bars 

    Tiessen, M.C.H.; Leeuwen, S.M.Van; Calvete Manrique, Daniel; Dodd, Nicholas (2010-01)
    Article
    Restricted access - publisher's policy
    A morphodynamical linear stability analysis is used to predict the natural development of crescentic bed patterns and rip channels. The purpose is to investigate whether this technique, which is useful for understanding ...
  • A mechanism for sandbar straightening by oblique wave incidence 

    Garnier, Roland; Falqués Serra, Albert; Calvete Manrique, Daniel; Thiebot, Jerome; Ribas Prats, Francesca (2013-06-06)
    Article
    Open Access
    Breaker bars in the surf zone of sandy beaches generally evolve between straight bars parallel to the shore and meandering crescentic bars associated with intense (dangerous) currents flowing seaward through rip channels. ...
  • A mechanism inhibiting rip channel formation for oblique waves 

    Garnier, Roland; Dodd, Nicholas; Falqués Serra, Albert; Calvete Manrique, Daniel (World Scientific Publishing Company, 2009)
    Conference lecture
    Restricted access - publisher's policy
    Previous numerical modelling studies based on 2DH morphodynamical model show that oblique waves tend to inhibit the formation of rip channel systems, but the mechanisms were not investigated. Field observations do not ...
  • A model for grain-size sorting over tidal sand ridges 

    Walgreen, M; de Swart, Huib E.; Calvete Manrique, Daniel (2004-07)
    Article
    Restricted access - publisher's policy
    A model was developed and analyzed to quantify the effect of graded sediment on the formation of tidal sand ridges. Field data reveal coarse (fine) sediment at the crests (in the troughs), but often phase shifts between ...
  • A model for sand ridges on the shelf: effect of tidal and steady currents 

    Calvete Manrique, Daniel; Walgreen, M.; Swart, Huib E. de; Falqués Serra, Albert (2001-05)
    Article
    Open Access
    The dynamics of sand ridges, as observed on the innershelves and midshelves of various coastal seas, are investigated within the framework of an idealized model. These seabed undulations include shoreface-connected sand ...
  • A new instability mechanism related to high-angle waves 

    Falqués Serra, Albert; Kakeh Burgada, Nabil; Calvete Manrique, Daniel (2018-06-27)
    Article
    Restricted access - publisher's policy
    Waves with a large incidence angle in deep water can drive a morphodynamic instability on a sandy coast whereby shoreline sand waves, cuspate forelands, and spits can emerge. This instability is related to bathymetric ...
  • A new shoreline instability mechanism related to high-angle waves 

    Falqués Serra, Albert; Kakeh Burgada, Nabil; Calvete Manrique, Daniel (2017)
    Conference report
    Open Access
    A new shoreline instability triggered by high-angle waves and leading to sand wave formation is investigated. In contrast with the well-known high angle wave instability, which involves both the surf and shoaling zones and ...
  • A new shoreline instability mechanism related to high-angle waves 

    Kakeh Burgada, Nabil; Falqués Serra, Albert; Calvete Manrique, Daniel (2017)
    Conference lecture
    Open Access
    The alongshore wave driven sediment transport can render a rectilinear coastline unstable in case of very oblique wave incidence.
  • An idealised study for the long term evolution of crescentic bars 

    Chen, W.L.; Dodd, Nicholas; Tiessen, M.C.H.; Calvete Manrique, Daniel (2018-01-01)
    Article
    Open Access
    © 2017 Elsevier Ltd. An idealised study that identifies the mechanisms in the long term evolution of crescentic bar systems in nature is presented. Growth to finite amplitude (i.e., equilibration, sometimes referred to as ...
  • A nonlinear model study on the long-term behaviour of shore face-connected sand ridges 

    Calvete Manrique, Daniel; Swart, Huib E. de (2003-05)
    Article
    Open Access
    A morphodynamic model is analyzed to gain further knowledge about the finite amplitude behavior of shore face–connected sand ridges observed on storm-dominated inner shelves. The present work elaborates on previous studies ...
  • Comparison of modelled nearshore transverse sandbars with field observations 

    Ribas Prats, Francesca; Calvete Manrique, Daniel; Falqués Serra, Albert (2010)
    Conference report
    Open Access
  • Dynamics of shoreface-connected and inactive sand ridges on a shelf, Part 2: The role of sea level rise and associated changes in shelf geometry 

    Nnafie, Abdel; de Swart, Huib E.; Calvete Manrique, Daniel; Garnier, Roland Charles (2015-08)
    Article
    Open Access
    Many inner continental shelves are characterized by the presence of large rhythmic bedforms, such as shoreface-connected ridges and the more offshore located sand ridges, which have heights of several meters and are spaced ...
  • Effect of depth-dependent wave stirring on the final amplitude of shoreface-connected sand ridges 

    Calvete Manrique, Daniel; Swart, Huib E. de; Falqués Serra, Albert (2002-12)
    Article
    Restricted access - publisher's policy
    A nonlinear morphodynamic model is analysed to gain fundamental knowledge about the initial growth and long-term behaviour of observed shoreface-connected sand ridges. Themodel describes quasi-steady, depth-averaged flow ...
  • Effect of grain size sorting on the formation of shoreface-connected sand ridges 

    Walgreen, M; Deswart, H E; Calvete Manrique, Daniel (2003-03)
    Article
    Open Access
    Field data of shoreface-connected ridges show persistent spatial variations of mean grain size over the bed forms. In the shore-normal direction, the profiles of bottom topography and mean grain size are approximately 90° ...
  • Effect of surface rollers on the formation crescentic bars 

    Calvete Manrique, Daniel; Ribas Prats, Francesca; de Swart, Huib E.; Falqués Serra, Albert (2011)
    Conference lecture
    Restricted access - publisher's policy
    The effect of surface rollers on the formation of crescentic bars/rip channel systems is examined with a morphodynamic model. A linear stability analysis is applied to find the fastest growing bottom patterns that develop ...
  • Effect of surface rollers on the formation of crescentic bars: large angles of incidence 

    Calvete Manrique, Daniel; Ribas Prats, Francesca; Swart, Huib E. de; Falqués Serra, Albert (2012)
    Conference lecture
    Open Access
    The formation of crescentic bars is examined using a morphodynamic model based in linear stability analysis. The effect of surface rollers for off-normal wave conditions is examined. The effect of the rollers is to increase ...
  • Effect of wave-bedform feedbacks on the formation of, and grain sorting over shoreface-connected sand ridges 

    Vis-Star, Nicolette C.; Swart, Huib E. de; Calvete Manrique, Daniel (2009-11)
    Article
    Restricted access - publisher's policy
    The influence of wave–bedform feedbacks on both the initial formation of shoreface-connected sand ridges (sfcr) and on grain size sorting over these ridges on micro-tidal inner shelves is studied. Also, the effect of ...
  • Effect of wave-topography interactions on the formation of sand ridges on the shelf 

    Vis-Star, Nicolette C.; Swart, Huib E. de; Calvete Manrique, Daniel (2007-06)
    Article
    Open Access
    The role of wave-topography interactions in the formation of sand ridges on microtidal inner shelves is investigated with an idealized morphodynamic model. The latter uses the two-dimensional shallow water equations to ...
  • Effects of sea level rise on the formation and drowning of shoreface-connected sand ridges, a model study 

    Nnafie, Abdel; Swart, Huib E. de; Calvete Manrique, Daniel; Garnier, Roland (2014-06-01)
    Article
    Restricted access - publisher's policy
    Shoreface-connected sand ridges occur on many storm-dominated inner shelves. These rhythmic features have an along-shelf spacing of 2-10 km, a height of 1-12 m, they evolve on timescales of centuries and they migrate several ...
  • Formation of shoreface-connected sand ridges: effects of rigid-lid approach, quasi-steady approach and wave-topography feedbacks 

    Nnafie, Abdel; de Swart, Huib E.; Garnier, Roland; Calvete Manrique, Daniel (2011)
    Conference lecture
    Restricted access - publisher's policy
    The initial- and long-term evolution of shoreface-connected sand ridges (sfcr) is investigated with a new nonlinear model (MORFO56) that employs finite difference methods, rather than spectral methods. MORFO56 uses ...