The French Vigilance System. Contributing to the Reduction of Disaster Risks in France
Managing natural risks has been a major concern for France ever since the 1950s. The relevant mechanism, which initially focused on operational response on-site then on prevention, relied on specific weather forecasts tailored to the needs of each user. Following the storms of December 1999 whose severe impact could have been lessened by provision of better information to the public, it was decided to introduce a new mechanism that utilized a common language – a four-colour scheme reflecting different risk levels. This would be applied at the scale of the French département, the administrative division of the national territory which is best suited to planning and crisis management. It would also be applied on a 24-hour time frame that combined satisfactory forecasting reliability with sufficient advance warning for action.
Following the storms of December 1999, whose severe impact could have been lessened by better information of the public, the Ministry of the Interior, the Ministère de l’Ecologie, de l’Energie, du Développement Durable et de la Mer (MEEDDM) introduced a new mechanism relying on a common language: a four-colour scheme reflecting different risk levels, used at the scale of the French département, the administrative division of the national territory which is best suited to planning and crisis management, along with a 24-hour time frame combining satisfactory forecasting reliability with sufficient advance warning for action.
This simple common language allows the French weather service to disseminate widely its “potential risk” forecasts linked to meteorological criteria in the form of a “Vigilance map”. Information is transmitted simultaneously to civil defence authorities, national operators, the media and the general public. Even though this information is basically a meteorological forecast, this clear and unified signal triggers a preventive response which is accompanied, as need be, by status reports, personalized briefings and imagery in order to enable each decision-maker to react accordingly. As the general public receives clear risk information from the authorities accompanied by safety guidelines, it can also play a role in ensuring its security.
This mechanism, originally designed for five types of weather hazards, namely high winds, heavy precipitation, storms, snow/ice and avalanches, was broadened in 2003 to include heatwaves and intense cold episodes. In 2007, the parameter “heavy precipitation” was changed to “rains/flooding”, thanks to the operational cooperation with the flood prediction network. There are also some specific features in the overseas territories, mainly in relation to tropical cyclones, as presented in the Appendix. These developments reflect a commitment to improve the system, which has demonstrated its value in the implementation of the French policy for reducing the risk of natural disasters in France, and is now well known to French citizens: in 2008, a survey revealed that the Vigilance was known by 86 per cent out of a statistically significant sample of 2000 people.