Mediterranean Extreme Floods and Flood Risk : The Hydrogeomorphological Method

Jean-Louis Ballais (1, 2)

1 AMU ALLSH - Aix-Marseille Université - Faculté des Arts, Lettres, Langues et Sciences Humaines
2 ESPACE - Études des Structures, des Processus d’Adaptation et des Changements de l’Espace

Nowadays, in the valleys surrounding rivers, the problematic of flood hazard leads to observe familiar functional floodplain objects from a point of vview slightly different from those generally admitted in fluvial dynamics. Interest in microtopography and its variation thus allows us to distinguish up to four beds in a Mediterranean watercourse valley. Currently under development, the hydrogeomorphological method already has produced new results wuith the description of exceptional high waterbeds in some watercourses in Mediterranean France and Tunisia. Building up of numerous Mediterranean functional flood plains began during Classical Antiquity. The high water bed finegrained formations have accumulated during the Middle Ages and the Modern and Contemporary periods. Using isotopic dating, we were able to show that this trend goes on during the second part of the 20th century and should continue in the future. Those formations are mainly produced by soil erosion due to cultural practices.

Mots clés: hydrogeomorphology, risk, functional alluvial plain, beds, flood

Domaines: Sciences de l'environnement

Jean-Louis Ballais. Mediterranean Extreme Floods and Flood Risk : The Hydrogeomorphological Method. Theano S. Terkenli, Annick Douguédroit, Louis F. Cassar. Connections, Mobilities, Urban Prospects and Environmental Threats - The Mediterranean in Transition, Cambridge Scholars Publishing, pp.239-262, 2015. ⟨hal-01586923⟩