Lessons from the autumn 2014 flash floods in the city of Nîmes and its neighborhood (France): behaviour of several mitigation dams and hydrological analysis
Les leçons des crues éclairs de l'automne 2014 dans la ville de Nîmes et ses quartiers : le comportement de plusieurs barrages écrêteurs de crues et analyse hydrologique
Fouchier, C. ; Mériaux, P. ; Pla, G. ; Nuel, J.L. ; Retailleau, E. ; Royet, P.
Type de document
Communication scientifique avec actes
Affiliation de l'auteur
IRSTEA AIX EN PROVENCE UR RECOVER FRA ; IRSTEA AIX EN PROVENCE UR RECOVER FRA ; CITY OF NÎMES FRA ; CITY OF NÎMES FRA ; GARDON RIVERS SMAGE NIMES FRA ; IRSTEA AIX EN PROVENCE UR RECOVER FRA
Résumé / Abstract
The Languedoc area, in Southern France, is prone to autumnal flash floods which are characteristic of the Mediterranean climate. To cope with this threat, the local authorities have chosen to build several dams on the main dangerous rivers of the area. We have focused on the flood mitigation facilities of two operators: the City of Nîmes and the Gardons Rivers Managing authority. After the catastrophic flash flood of October 1988, the city of Nîmes built flood mitigation dams on many of its high-risk streams. These flood barriers worked several times during the intense rainfalls of autumn 2014. The on-site conclusions drawn from these floods and the computation carried out with hydrological models confirmed how well the dams functioned. In 2010, the Gardons Rivers Managing authority built a flood mitigation dam on the Esquielle River to protect the village of Saint-Geniès-de-Malgoirès. The spillway of this dam worked for the first time in the autumn of 2014. We analysed one of the major floods monitored on that occasion at its outlet. The goals of this study are: (i) to evaluate dams efficiency and (ii) to test, on a catchment which was not used for its calibration, the AIGA flash flood warning method, which was developed by IRSTEA.
3rd European Conference on Flood Risk Management FLOODrisk 2016, 17/10/2016 - 21/10/2016, Lyon, FRA
E3S Web Conf. Volume 7, 2016. 3rd European Conference on Flood Risk Management (FLOODrisk 2016)