WP2 PhD n°1 : Contributions des houles australes exceptionnelles aux évènements de submersion marine extrêmes passés (2022-2025)
Axelle Gaffet
Supervisor(s) : Xavier Bertin, Senior researcher CNRS, La Rochelle Université, LIENSs ; Damien Sous, Professor assistant, Université de Pau et des pays de l’Adour, SIAME ; Baptiste Le Mauff, project manager at Créocéan
Due to the concentration of populations and associated activities in coastal areas, the increase in coastal hazards and the degradation of coral reefs linked to global change, tropical islands will face an alarming increase in coastal risks in the coming decades. Major submersion events can occur in the wake of a tropical cyclone, but also as a result of exceptional distant swells, a phenomenon little known until now. Over the past decade, understanding of the contribution of waves to extreme sea levels has progressed enormously, thanks to studies combining field observations and high-resolution numerical simulations. The representation of tropical sea states must be improved and the the major events of the past decades need to be revisited, to better understand and quantify the importance of setup and infragravity waves in the associated marine submersions.
WP2 PhD n°2 : Analysis of Storm Surges and Coastal Flooding Caused by Cyclones in the French Tropical Islands Over the Past Four Decades (2023-2026)
Lola Ormières
Supervisor(s) : Xavier Bertin, Senior researcher CNRS, La Rochelle Université, LIENSs ; Franck Dollique, Professor, Université des Antilles, IRD, BOREA MNHN ; Yann Krien, Assistanr professor, LEGOS
As tropical islands face increasing hazards from extreme sea levels and marine submersion due to climate change, sea level rise, possible intensifying cyclones, and the degradation of coral reefs, this research aims to better understand the key processes driving coastal risks such as marine submersion. The study will combine the analysis of both observational data and numerical simulations. While atmospheric storm surge is relatively well understood, the contribution of wave energy dissipation at the coast to water level along with its interactions with complex features such as rough seabeds (e.g., reefs), currents, and tides remains less studied and poorly understood. Using data from recent field surveys (e.g., Mayotte 2023, Guadeloupe 2017), the project will investigate the physical mechanisms influencing coastal mean water levels during past extreme events, supported by coupled wave–hydrodynamic modeling.
WP2 PhD n°3 : Représentativité et incertitudes de l'aléa cyclone dans les territoires français d'Outre-mer (2023-2026)
Aline Zribi
Supervisor(s) : Xavier Bertin, Senior researcher CNRS, La Rochelle Université, LIENSs ; Swen Jullien, CR, LOPS ; Guillaume Dodet, CR, LOPS
WP2 PhD n°4 : Processus de transformation des vagues en contexte récifal (2023-2026)
Mila Geindre
Supervisor(s) :
WP3 PhD n°5 : L’intérêt d’une approche Passé-Futur pour soutenir l’adaptation côtière au changement climatique : application aux îles françaises du Pacifique (Nouvelle-Calédonie, Polynésie française) (2023-2024)
Maëlys Girault
Supervisor(s) : Virginie Duvat Professor of coastal geography, La Rochelle Université, LIENSs ; Alexandre Magnan, researcher, Cawthron Institute
WP3 thèse n°6 : Une approche intégrée pour évaluer l’impact des risques climatiques composés dans le contexte des petites îles (2023-2026)
Mirna Badillo
Supervisor(s) : Virginie Duvat, Professor of coastal geography, La Rochelle Université, LIENSs ; Gonéri Le Cozannet, researcher, BRGM ; Jérémy Rohmer, researcher, BRGM
Atoll islands will be increasingly affected by climate-related changes, such as sea level rise, rising temperatures, and ocean acidification. These changes will simultaneously affect multiple dimensions of atoll island systems (environmental, social and economic), challenging their resilience. This research aims to better understand the complex interactions between climatic and non-climatic factors that influence the habitability of these islands. It proposes the development of an integrated model, based on Bayesian networks, to assess the future impacts of climate change on key dimensions of habitability (Duvat et al., 2021), such as food security, access to freshwater, the availability of habitable land, and economic activities.