Analyse fréquentielle des crues de l’oued Seybouse et ses principaux affluents

Abstract

In the basin of the wadi Seybouse floods related to the weather, constituting the most feared natural risk by residents. The frequency and magnitude of these phenomena observed in the Seybouse basin clearly show that these hazards constitute a foreseeable risk. Its importance depends on three parameters : the water level, the speed of the current and the duration. It depends on the rainfall, the state of the watershed (relief, hygroscopy, occupation) and the characteristics of the watercourse (depth, width, slope, etc.).In the absence of sufficient information on all the rivers in the basin studied, the importance of the street is appreciated according to its frequency. The results of frequency analyzes of rainfall and extreme flows recorded at the Mirbek station, extrapolated to the Seybouse basin and the main sub-basins, made it possible to develop some empirical models and to estimate project floods (10-year, 50-year floods, and centennial) for structural improvements. These results can feed a hydraulic model of the open-air flows allowing to provide, for any profile, the width of the submerged zone, the submersion dimensions, the distribution of flows and flow velocities ; information required for flood risk mapping. These documents constitute an easement of public utility, make it possible to answer, at the same time, the requirement of protection and prevention and the preservation of the stakes in the floodplains within the framework of the durable development.