NIVEXT project (extreme sea level)


This project, funded by the General Directorate for Risk Prevention (MEDDE) aims to improve knowledge of extreme levels on the Atlantic coast, English Channel (and Mediterranean). It is divided in two phases for a total planned duration of three years:


Historical extreme levels:

This phase involves inventorying and analysing historical tide gauge records during extreme events of coastal flooding in the English Channel and the Atlantic since 1850. This first phase is carried out in collaboration with Météo-France.


Archives marégraphiques à fort potentiel (marégrammes de 1850 à nos jours)

Example of tidal archives stored at SHOM



Tide curves: the key to studying instant extreme sea levels


Tide record of a storm in Marseille on August 5, 1985

Hauteur d'eau horaires disponibles sur REFMAR


Marégramme (source IGN) : Visualisation des effets de la tempête

Hourly water level available on REFMAR                                      Tide curve (Source IGN):  Graphic view of the effects of the storm


  • Benefits

    • Provide additional information about statistical extreme levels
    • Help determine the water level thresholds for the future warning system
    • Integrate these data to consolidate the extreme levels of reference (risk prevention plans)
    • Provide new data sets for hydrodynamic modelling. 
  • Users

    • Agencies involved in implementing the storm surge flood warning system
    • Agencies involved in the evaluation or review of storm surge flood risk (flood risk prevention plans)
    • Scientific community (research / modelling)
    • Coastal stakeholders (developments).


  • Example:

    • Study of historical extreme levels in the Gulf of Lion (CETE MEd, DREAL LR)


Statistical extreme levels:


This phase provides technical support for the thesis of X. Kergadallan on the statistical estimation of extreme levels in the English Channel, Atlantic and Mediterranean, funded by CETMEF.


To find out more:  



Last updated: 12/12/2012

List of projects based on tide gauging:

List of programs, projects and reconstructions of tide gauge data