Dynamics of a Free Aquifer in Response to Hydro-Sedimentary Forcing at the Watershed Scale Over a Multi-Decadal Period

Understanding the hydro-sedimentary dynamics at the watershed scale in response to daily or multi-year forcing is a key challenge in assessing the impact of climate change on water resources. Numerical modeling emerges as a central tool in this context to prioritize couplings according to their significance, and ultimately to allow a quantitative evaluation of this resource under different climate scenarios. Many numerical models enable the simulation of water flows on the surface and in the subsurface, as well as sediment transport at various temporal and spatial scales. However, it's less common to find an integrated numerical strategy applicable to a watershed with complex topography, which offers reduced computation time and supports "multi-realization" approaches. The objective of this thesis is to develop such a digital solution. We plan to implement a transient subsurface water flow model using a Dupuit-Forchheimer-type free aquifer model coupled with an infiltration model. Infiltration conditions are controlled by water fluxes and sediment distribution on the surface. These surface hydro-sedimentary regimes will be modeled using a Saint-Venant-type approach, which can adapt to the scale of the considered event (intense but localized rainfall, or long-term climate change). Once the model is implemented, we plan to validate it by simulating the hydro-sedimentary response of a sub-basin in the Rhône Valley over several years.

Keywords: Climate Change, Hydro-Sedimentary Dynamics, Free Aquifer.

• Academic supervisors    Dr Mario Ricchiuto, INRIA Center, University of Bordeaux. Member of the CSM team (IMB). ORCID : 0000-0002-1679-7339 & Dr Martin Parisot, INRIA Center, University of Bordeaux. Member of the CSM team (IMB). ORCID : 0000-0001-7040-8384
• Doctoral School   ED39 Ecole Doctorale de mathématiques et informatique, Bordeaux
• IFPEN supervisor    Dr Benoit Chauveau, ORCID: 0000-0002-0282-6979
• PhD location    IFPEN, Rueil-Malmaison, France
• Duration and start date    3 years, starting in November 2024
• Employer    IFPEN
• Academic requirements    Master's Degree in Applied Mathematics.
• Language requirements    English Level B2 (CECR)
• Other requirements    Applied Mathematics, Programming (C++), Numerical Schemes, Interest in Geoscience.

To apply, please send your cover letter and CV to the IFPEN supervisor indicated here below.