A linear indexing approach to mass movements susceptibility mapping. The case of the Chefchaouen province (Morocco)
Résumé
the modelling of mass movements susceptibility (MMS) is essential for land-use planning and decision-making especially in the mountainous areas of Morocco. The main objective of this study is to create an MMS map for the Province of Chefchaouen in the north-western part of the Moroccan Kingdom using an index based approach (heuristic model). As a first step, mass movements (MM) features are identified in the study area by the interpretation of high-resolution remote-sensing data and from field investigations. Lithology, fault density, slope degree, slope aspect, elevation, stream density, land use, rainfall, and earthquakes equal-depths are identified as the main parameters controlling the occurrence of MM. Then, each parameter map is classified into a number of significant classes based on their relative influence for MM genesis. Rating values are assigned for each class, representing their influence on slope instability. The weights are extracted from real statistical data to reduce the subjectivity of the method. Finally, ROC (receiver operator characteristic) curves are drawn, and the areas below the curve (AUC) are measured to evaluate the degree of the model fit, and identify the best MMS map. This type of map can be valuable for general land-use planning, especially in Mediterranean mountainous areas.