Les inondations catastrophiques du 23 septembre 2009 dans la ville de Redeyef (Tunisie méridionale)

Abstract

On September 23, 2009 and by the end of the night, 150 mm of rain suddenly fell in the Redeyef region. This precipitation generated abundant urban runoffs and very violent floods in the Dakhla wadi (5.74 km2 upstream of Redeyef) and its tributaries (total area of 14.8 km2 downstream of the city). The runoffs and floods produced victims and caused significant damages. Despite limited knowledge about rainfall and lack of hydrological data, the present study focusses on the event mentioned above. It purports to investigate the connection, through the use of field data collected and the mapping of flooded areas, between the pluvio-hydrological conditions, the extension of the urban fabric, and developments influencing the flows. The September 23, 2009 exceptional floods in the Redeyef region, represent an example of the risks to which the localities bordering a wadi in an arid environment are exposed.

Keywords

• Tunisia
• exceptional rainfall
• torrential flows
• catastrophic flooding
• anarchic urbanisation
• Redeyef