PhD position on "Process-based modelling of the hydro-sedimentary Dynamics of a Coastal Continuum" (University of Bordeaux)
University of Bordeaux
Nonlinear Processes in Geosciences (NP)
Ocean Sciences (OS)
Coastlines worldwide encompass interconnected aquatic systems, including beaches, estuaries, bays, lagoons, and tidal channels, all of which play critical biological and ecological roles and serve as vital economic hubs for coastal communities (Xenopoulos et al., 2017). These coastal features are integral components of land-sea continuums, where interactions between terrestrial and marine environments shape complex hydrodynamic and sediment transport processes (Castelle and Masselink, 2023, Jalón-Rojas et al., 2017; 2018). Understanding these processes is crucial for effective coastal management and the sustainable utilization of coastal resources. Despite the interconnected nature of aquatic systems within the land-sea continuum (Staneva et al., 2019), hydro-sedimentary dynamics are often studied at individual spatial scales and/or by discriminated wave-dominated, tide-dominated environments and river-dominated, resulting in limited understanding of the interactions between systems and transport processes. A significant scientific challenge lies in evaluating sediment transfer between and through the continuum compartments, quantifying sediment fluxes and stocks, and elucidating on their feedback on morphology and hydrodynamics.
The coastal area of Labenne, Capbreton, Seignosse, and Hossegor comprises sandy coastlines, a coastal lake, and adjacent access channels, supplemented by a port and two freshwater tributaries, forming a land-sea continuum that is a perfect natural laboratory to address these challenges. This continuum is a complex and interconnected system in which hydrodynamic and sediment transport processes occur in a coupled and interdependent manner. For instance, the shoreline erosion of the Capbreton beaches downdrift of the northern training wall of the Boucarot Pass and the Hossegor Lake infilling, are tightly linked to the nearshore sediment bypassing the wall and entering the Boucarot Pass or depositing in Capbreton Canyon. Since 2007, an artificial sand bypassing system was implemented to increase the amount of sediment reaching the downdrift coast and further reduce shoreline erosion. The respective proportions of sediment fluxes reaching the downdrift, depositing in the Hossegor Lake and in the Capbreton Canyon head are virtually unknown. However, such information is crucial to guide coastal management and planning, including beach nourishment, sand bypassing strategy, dredging of the Boucarot mouth, etc.
The primary objective of this PhD is to advance fundamental understanding of the interactions between adjacent coastal systems, focusing on elucidating the hydrodynamics, transport processes, and fluxes of fine and sandy sediments along the continuum from the Labenne-Capbreton Sandy Coast to Hossegor Lake. The successful candidate will address major research questions such as:
- What are the dominant mechanisms driving hydrodynamics and sediment transport within the Labenne-Capbreton sandy coast to Hossegor Lake continuum?
- How do key forcings, including tides, waves, and riverine inputs, interact and influence sediment dynamics in the study area?
- What are the implications of sediment dynamics for coastal erosion, sedimentation rates, and the sediment budget of the system at seasonal scales?
- How will this coastal area evolve under varying hydro-climatic scenarios and/or management interventions?
The study will be based on numerical simulations conducted with the open-source TELEMAC-TOMAWAC-GAIA numerical model (Tassi et al., 2023). This model will enable the simulation of currents, waves, and sediment transport, providing valuable insights into the hydro-sedimentary evolution of the entire continuum. The model will be calibrated and validated using observations of hydro-sedimentary parameters (current velocities, water level, turbidity, salinity, bottom depth) obtained through an intensive field campaign led by a postdoc funded by the same project, as well as satellite-derived shoreline of the open coast. The study will enhance the understanding of coastal evolution, thereby supporting decision-making for coastal management and adaptation strategies.
CANDIDATE PROFILE: We seek highly motivated candidates with:
– MSc degree in Physical Oceanography, Environmental Physics, Marine Science, Fluid Mechanics, or a closely related discipline with a strong background in hydrodynamics and numerical modelling; – Training experience in numerical modelling (experience with TELEMAC particularly appreciated) and data analysis – Proven affinity with coastal physical oceanography; – Technical abilities in scientific programming (e.g Matlab, Python)The selected candidate should, if possible, have also the following qualities: autonomy, scientific curiosity, and open-mindedness. She/he should have if possible excellent teamwork, writing, and communication skills.
APPLICATION PROCEDURE. Applicants should send by email to Isabel Jalón-Rojas (isabel.jalon-rojas@u-bordeaux.fr), Aldo Sottolichio (aldo.sottolichio@u-bordeaux.fr) and Bruno Castelle (bruno.castelle@u-bordeaux.fr) with the documents listed below before May 10, 2024.
– Letter of motivation – CV – Master’s grades – Contact details of 2 referees