Author(s) Javelle, Pierre et al.

Flash flood warnings: Recent achievements in France with the national Vigicrues Flash system

31 May 2019

Source

United Nations Office for Disaster Risk Reduction

Publication Year

2019

Number of pages

20 p.

Flash floods (FF) events are difficult to forecast because of their small temporal and spatial scale. Furthermore, they often occur on un-monitored small rivers, where no real-time data is available to warn people. To better anticipate these events and mitigate their impacts, the French Ministry in charge of Ecology has launched a national FF warning system: Vigicrues Flash. This system takes real-time radar-gauge rainfall products at a 1-km² resolution from Météo-France and issues automatic flood warnings based on the Adaptation d’Information Géographique pour l’Alerte en Crue (AIGA) method at small un-gauged catchments (greater than 10-km²). AIGA aims to characterize flood hazard at any point along the river network by comparing discharges in real-time produced by a simplified distributed rainfall-runoff model (GRD) to reference flood quantiles obtained using the same model and a continuous radar-gauge rainfall re-analysis. Vigicrues Flash was launched in March 2017. The aim of this paper is to briefly present the new system and a first analysis of its performance during one exceptional large event that occurred in June 2018.

This paper is a contribution to the 2019 edition of the Global Assessment Report on Disaster Risk Reduction (GAR 2019).