Evaluating flash-flood warnings at ungauged locations using post-event surveys: a case study with the AIGA warning system |
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Authors: | Pierre Javelle Julie Demargne Dimitri Defrance Jean Pansu Patrick Arnaud |
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Affiliation: | 1. Irstea (formerly Cemagref), Centre Régional d’Aix-en-Provence, CS 40061, F-13182 Aix-en-Provence, Cedex 5, Francepierre.javelle@irstea.fr;3. HYDRIS Hydrologie, 5 Avenue du Grand Chêne, F-34270 Saint Mathieu de Tréviers, France;4. Irstea (formerly Cemagref), Centre Régional d’Aix-en-Provence, CS 40061, F-13182 Aix-en-Provence, Cedex 5, France;5. Météo-France, Direction Interrégionale Sud-Est, 2, Bd Chateau-Double, F-13098 Aix-en-Provence Cedex 2, France |
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Abstract: | AbstractThis article presents a comparison between real-time discharges calculated by a flash-flood warning system and post-event flood peak estimates. The studied event occurred on 15 and 16 June 2010 at the Argens catchment located in the south of France. Real-time flood warnings were provided by the AIGA (Adaptation d’Information Géographique pour l’Alerte en Crue) warning system, which is based on a simple distributed hydrological model run at a 1-km2 resolution using radar rainfall information. The timing of the warnings (updated every 15 min) was compared to the observed flood impacts. Furthermore, “consolidated” flood peaks estimated by an intensive post-event survey were used to evaluate the AIGA-estimated peak discharges. The results indicated that the AIGA warnings clearly identified the most affected areas. However, the effective lead-time of the event detection was short, especially for fast-response catchments, because the current method does not take into account any rainfall forecast. The flood peak analysis showed a relatively good correspondence between AIGA- and field-estimated peak values, although some differences were due to the rainfall underestimation by the radar and rainfall–runoff model limitations. Editor Z.W. Kundzewicz; Guest editor R.J. Moore Citation Javelle, P., Demargne, J., Defrance, D., Pansu, J. and Arnaud, P., 2014. Evaluating flash-flood warnings at ungauged locations using post-event surveys: a case study with the AIGA warning system. Hydrological Sciences Journal, 59 (7), 1390–1402. http://dx.doi.org/10.1080/02626667.2014.923970 |
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Keywords: | evaluation flash flood ungauged warning system post-event survey |
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