Abhatoo - Centre Nationale de Documentation

The application of specialized natural hazard mapping is an absolute necessity for the management and prevention of natural hazard events. This paper treats the description of all the procedures carried out in order to produce a map of vulnerability and susceptibility to cave-ins, calculated and evaluated by the multicriteria method (AHP) and by using the GIS tool in the old Medina of Beni Mellal, which is recognized from time to time by cave-ins. The objective of this study is to develop a new method for analyzing the vulnerability of cavities to collapse, which presents a real risk in the urban area of the old cities. The methodology, applied to the old city of Beni-Mellal, consists in identifying and quantifying the stakes linked to the collapse of a cavity using a geographic information system. The weight of each parameter and factor exposed in the vulnerability was estimated using the hierarchical multicriteria method (AHP). The result is presented in the form of a spatialized and synthetic vulnerability map. The detection, mapping and assessment of areas vulnerable to the collapse of these cavities, particularly for large areas of the city, offers the possibility of reducing damage by intervening upstream and introducing preventive and corrective measures against any risk of collapse in the areas deemed vulnerable by our study. The maps show three zones with different degrees of vulnerability. The low and medium vulnerability zones occupy respectively 30 and 20% of the total area of the old city, while the high and very high vulnerability zones occupy respectively 16% and 4%.