Study of the hydrological processes during the Avene river extraordinary flood (south of France): 6-7 October 1997

The Avene flood, with a peak discharge between 600 and 900 m(3)/s for a drainage area of 57 km(2), appears as one of the most important flash floods reported in the French Mediterranean area during the last decades for similar catchment areas. The watershed is ungauged and interviews were conducted to gather valuable information about the flood sequence. Most of the collected data seems reliable. These data indicate that the swelling of the Avene river was sudden and late compared to the measured rainfall sequence. The flood appears to have been mainly produced by surface runoff. Moreover, the late response of the watershed shows that its thin soils, dried out during the preceding summer period, had surprisingly high infiltration rate and capacity: estimated about 100 mm/h and 200 mm. respectively. (C) 2003 Elsevier Science Ltd. All rights reserved.