La vulnerabilité face aux risques naturels etude de cas la ville de constantine.

Abstract

This work focuses on the contribution of hazard susceptibility and vulnerability to mapping risks related to the landslide hazard in Constantine. For this purpose, our interest was focused on the development of a methodological approach which uses the application of a Geographic Information System (GIS), using multi-criteria analysis that takes into account various natural physical parameters of the site:( geology and or lithology of soils, geomorphology, hypsometry, slope inclination ) and anthropogenic : (land use and population), this first allowed us to produce the hazard susceptibility map using a bivariate approach (GMM-MATRIX). It classifies the different areas of the site in relation to natural phenomena (alea) and secondly the vulnerability estimate, which is estimated by a semi-empirical analysis of the issues defined in terms of the relative value of exposed elements (structural vulnerability and physical vulnerability). The superimposition between the latter (alea and vulnerability) has led to the elaboration of a thematic map grouping the different classes of landslide risk (very high, high medium and low and very low) in the study area. For the site as a whole, about 1147 h of the total area is exposed to a very high to high risk 219 h to a medium risk and 19021 h is classified as low risk. Thus this map allowed us to highlight for the whole city, the number of constructions exposed to a very strong risk to strong 551 of the total number, 564 constructions has an average risk and 3379 constructions does not risk any danger. Finally, the result of this work (the landslide natural risk map, represents a decision support tool for the choice of preventive measures to reduce the risks in order to minimize the landslide impact of the city of Constantine).