Propagation des houles et des surcotes extrêmes vers les côtes et estuaires Apports de la modélisation numérique

Propagation of extreme waves and storm-surges towards coastal zones and estuaries. Contributions of numerical modelling

Laboratoire National d'Hydraulique et Environnement (LNHE) Electricité de France - Division Recherche et Développement 6, quai Watier, BP 49, 78400 Chatou, France Fax: + 33 (0)1 30 87 80 86

Abstract

At the interface with the ocean, the shore is exposed to the actions of the sea which govern its natural evolution (sometimes imperilling the integrity of the coastline), and affect, during storm events, the safety of human beings and patrimony located in the coastal area (stability of protection works, risk of submersion). In order to evaluate these risks and to prevent them through suitable measures of protection, it is necessary to consider simultaneously the effects of wind waves, marine currents, tides and storm surges. For several years, the LNHE has been developing a numerical modelling system (TELEMAC), based on various coupled modules, which allows to hindcast, and potentially to forecast, the combined effects due to the astronomical ride and to the atmospherical forcing (storm surges and waves). This modelling system has been successfully applied at continental scales (Atlantic coastlines of France, English Channel, North Sea), as well as regional scales (Dover Straits, Gironde estuary) for various extreme meteorological conditions.