Mapping of vulnerability of flooded area in arid region. Case study: area of Ghardaïa-Algeria

Abstract

The issue of natural hazards in general and flooding in particular is a hot topic which marks memorable actions in the world and specifically in Algeria. Managing this risk is becoming more of a necessity that must include all stakeholders and all possible means available. The objective of this work is the vulnerability mapping of flood areas in the arid region Oued M’zab-region Ghardaia. It’s about implement predictive models and flood control. This allows the development of a risk prevention plan to flooding. To achieve this goal we evaluated the hazard and vulnerability. The evaluation of the risk passes by a study of the mode of rising. This study leads to the determination of the synthetic hygrogram which are taken into account under the boundary conditions upstream of a hydraulic model of the nonpermanent flows on free face. The results obtained for one period of return given constitute the risk of the floods relating to these hydrograms. The vulnerability is represented by a rate which translates the objective of protection against a probable risk. Two types of models are tested on a section of Oued M’zab-region where the data are available. Initially, are considered hydrological models (HEC-HMS 1D). In the second place of the hydraulic models (HEC-RAS 1D). After comparison of the results obtained by various simulations, the vulnerable zones are thus charted.