new postdoc position in France: hydrosedimentary transport modelling in the English Channel
Lena Alekseenko
Postdoc position in LOG (Wimereux, France) for the period of January 2024 to December 2025.
Title: Study of the impact of wind farms on sediment transport. Approach by modeling and in situ observations
France has ambitious goals for the development of renewable energies, particularly offshore wind energy. All coastal areas of mainland France possess significant wind resources and industrial infrastructure. One of the challenges lies in establishing an offshore wind farm off the coast of Dunkirk. Comprising 45 wind turbines, this park is expected to generate 2.3 TWh of electricity annually starting in 2026. This would cover approximately 40% of the electricity demand in the Nord department. However, the construction of the park has led to changes in the marine environment and flow conditions, particularly in the dynamic English Channel, with implications for the coastal zone's morphodynamic equilibrium and local biodiversity.
It is imperative to consider hydro-sedimentary processes resulting from the interaction between structures and flows, both on a larger spatial scale and over an extended timeframe. This is vital because the environmental consequences of this interaction may not become immediately apparent. To address these concerns, multi-year 3D hydrodynamic and sedimentary modeling, coupled with observational data, can provide valuable understanding into the impact of abiotic and anthropogenic forces on hydro-sedimentary patterns. This modeling approach also helps elucidate how offshore wind farms can influence sediment transport regimes and sediment composition.
The proposed research project aims to quantify suspended matter characteristics (concentration, fractions, flows) in the water column and the morphodynamics of sediments in close proximity to offshore structures (wind turbine supports) as well as farther away from them. Simulations will be conducted over varying time spans, ranging from days to several years, and under the influence of various forces such as turbulence, strong winds, tides, coastal inputs, and atmospheric influences. This approach should enable the assessment of potential erosion and sediment deposition areas within the study area and how they evolve over time. Changes in the substrate can have a significant impact on the local ecological balance and, subsequently, the overall environment.
Within the framework of this project, a sediment transport model (MUSTANG, IFREMER) will be integrated with a hydrodynamic model (MARS3D, IFREMER), which can operate independently or simultaneously. The hydrodynamic and transport equations employed in this project have been detailed by Lazure and Dumas (2008), Le Hir et al. (2011), and Mengual et al. (2017). The primary focus of this project is on the precise parameterization and calibration of the coupled model using available data from the English Channel. The MARS3D model manages particle advection in the water column in a three-dimensional context, while the MUSTANG module handles the deposition of particles in the water column and their interactions with the sediment layer through processes like erosion, deposition, and consolidation. The selection of primary particle size classes should be guided by available sediment particle size data, followed by the appropriate parameterization and calibration of deposition, erosion, and consolidation processes.
All interested candidates should contact Elena Alekseenko and Alexei Sentchev by emailing elena.al...@univ-littoral.fr and alexei....@univ-littoral.fr and should send their CV and motivation letter as soon as possible.
References
1. Lazure P. and Dumas F., 2008. An external-internal mode coupling for a 3D hydrodynamical model for applications at regional scale (MARS). Adv.Wat. Res. 31 : 233–250.
2. Le Hir P, Cayocca F, Waeles B., 2011. Dynamics of sand and mud mixtures: a multiprocess-based modelling strategy. Cont Shelf Res 31: S135-S149.
3. Mengual B., Le Hir P., Cayocca F. and Garlan T., 2017. Modelling fine sediment dynamics : towards a common erosion law for fine sand, mud and mixtures. Water 2017, 9(8), P. 564 (1-24) ; https ://doi.org/10.3390/w9080564.