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Laurent Lacaze

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Laurent Lacaze
DR CNRS – HDR
IMFT – UMR 5502
31400 Toulouse, France
Email: laurent.lacaze@imft.fr
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News

 

  • 2025 — Review in Exp. in Fluids 
    Experimental Insights into Cross-Shore Morphodynamics of Beaches and Cliffs

    Lacaze L., Astruc D. and Moulin F.

    Conceptual diagram of the littoral zone subjected to wave forcing.     Dissipation coefficient as a function of the Dean number and beach slope β as a function of a dimensionless timescale based on bore height incoming the swash for various experimental configurations. The data originate from facilities of varying sizes (ranging from 10 m to 330 m) under different types of wave forcing.









    This review aims to provide an overview of laboratory models of nearshore morphodynamics, focusing specifically on the role of wave action. In this context, shoreline evolution is driven by the direction of sediment flux induced by wave dynamics, corresponding to erosion or accretion processes. These processes, which naturally modify the shape of coastlines, are influenced by factors such as sediment availability, wave climate, and soil strength, among others.
    Starting from unconsolidated sandy materials and the equilibrium-based concepts used in natural beach classification, the reanalysis of laboratory experiments shows that they can reproduce natural conditions and serve as conceptual models for understanding nearshore morphodynamics. However, the temporal evolution of the shoreline and the source of available sand are difficult to capture through equilibrium-type physical processes and therefore requires a specific focus on localized zones of the nearshore, depending on the prevailing hydrodynamics and sediment strength, i.e. consolidation.
    Accordingly, the local dynamics near the shoreline are closely linked to the behavior of the swash zone and to cliff erosion processes, which constitute a central focus of this review from a laboratory experiment perspective.

Research activities

  • Dense and dilute granular flows
    • shear-driven: transport in rivers, coastal morphdynamics
    • gravity-driven: avalanches, turbidity currents.
    • rheology of dense granular media: from dry to immersed
  • Local fluid-particle interaction
    • Bouncing
  • Non-newtonian fluids
    • shearing ealsto-viscoplastics fluids
    • free surface flows
  • Waves and instabilities :
    • wakes in stratified fluids
    • free-surface bores
    • rotating flows