1856 sur le bassin de la Loire : un événement hydrologique, hydraulique et humain tout à fait reproductible dans son ampleur spatiale et sa gravité

Why should a flood like the 1856’s Loire flood still happen today but with a worse hydraulical and socio-economical impact ?

Directeur de l’Equipe pluridisciplinaire du plan Loire grandeur nature, agence de l’eau Loire Bretagne B.P. 6339, 45063 Orléans cedex 02

Auteur de correspondance : nicolas-gerard.camphuis@cepri.net

Abstract

Three huge floods in 20 years have been a real and total disaster in 1846, 1856 and 1866, on the Loire river basin. After such a disaster, the protection by levees has been reinforced and every believed, ten years ago, that such a flood couldn’t more have the same impact. But as calculated with a hydraulic model built in 1998, a flood like the 1856’s will overtop the existing levees and breach them in many places. Big cities along the Loire will be flooded with a worse damage because they are ten times more people and a lot of industrial areas in the flood plain. Today, such a flood will be worse and very expansive, but people and local authorities are aware on the need to be prepared to this event!