A systemic and comprehensive assessment of coastal hazard changes: method and application to France and its overseas territories

• Main Authors: Igigabel, Marc, Yates, Marissa, Vousdoukas, Michalis, Diab, Youssef
• Other Authors: Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), École des Ponts ParisTech (ENPC), University of the Aegean, LAB'URBA (LAB'URBA), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Gustave Eiffel
• Format: Other/Unknown Material
• Language: French
• Published: HAL CCSD 2024
• Subjects: climate change; coast; hazard; change; assessment; method; systemic; changement climatique; littoral; aléa; évolution; évaluation; méthode; systémique; [SDE]Environmental Sciences; [PHYS]Physics [physics]; Sea ice
• Online Access: https://hal.science/hal-04690934; https://hal.science/hal-04690934/document; https://hal.science/hal-04690934/file/NHESS-2023-154_FR_Igigabel%20et%20al_2024.pdf

Edition française de l’article « Igigabel, M., Yates, M., Vousdoukas, M., and Diab, Y., 2024. A systemic and comprehensive assessment of coastal hazard changes: method and application to France and its overseas territories, Nat. Hazards Earth Syst. Sci., 24, 1951–1974 » Igigabel, M., Yates, M., Vousdoukas, M., and Diab, Y., 2024. Évaluation systémique et globale des évolutions des risques côtiers : méthode et application à la France et à ses territoires d'outre-mer. Édition française par le Cerema de l’article « Igigabel, M., Yates, M., Vousdoukas, M., and Diab, Y., 2024. A systemic and comprehensive assessment of coastal hazard changes: method and application to France and its overseas territories, Nat. Hazards Earth Syst. Sci., 24, 1951–1974 » In the context of climate change, height and frequency variations in extreme sea levels (ESLs) are studied using deterministic and probabilistic approaches. However, this type of approach does not highlight the dynamic effects (waves, currents) generated by metocean events (storms, cyclones, long swells, and tsunamis) beyond their effects on sea levels. In particular, ESL estimates are calculated by considering the main determining physical factors but cannot include all the effects of these factors. Ultimately, this can lead to confusion between ESL and hazard. This article proposes a systemic assessment method to analyze coastal hazard changes at regional scales, integrating parameters influencing sea levels, as well as factors describing the geomorphological context (length and shape of the coast, width of the continental shelf), metocean events, and the marine environment (e.g., coral reef state and sea ice extent). French mainland and overseas territories were selected to apply the method. The present study highlights the need to consider not only the sea level variability, but also the current and future characteristics of metocean events. The long, concave coasts bordered by a wide continental shelf appear particularly sensitive to variations in the intensity ...