Involvement of geomorphological factors on the occurrence of mass movements along the Southern Escarpment of the Bamileke Plateau (West-Cameroon)

Abstract

<p>Mass movements are phenomena which, due to their random nature, generate very significant risks, affecting the human heritage. The Southern Escarpment of the Bamileke Plateau (ESPB) is a region with a rugged relief. This relief, associated with climatic bad weather, is the seat of numerous instabilities linked to mass movements. This study aims to establish a relationship between geomorphological factors and mass movements along the Southern Escarpment of the Bamileke Plateau. The methodological approach used in this work is based on the inventory of mass movements from field campaigns and the exploitation of satellite images as well as the mapping of geomorphological factors. The geomorphological map, the slope map and the slope direction map are the factor maps that were used to assess the occurrence and susceptibility to mass movements in the region. Based on the field observations and satellite images, a spatial distribution map of mass movement was obtained. This map reveals that landslides are the most significant mass movement in the study area with a representativeness rate of 90% compared to subsidence and rock falls which represent respectively 5% of recorded mass movements.  The steepest slopes are the areas with the highest concentration of landslides in the region. The susceptibility map obtained from the geomorphological factor maps reveals that 16.95% represent low probability areas, 43.39% represent moderate probability areas, 29.77% represent high probability areas and 9.89% represent very high probability areas. The superimposition of the susceptibility map on the spatial distribution map of mass movements allows the relevance of this susceptibility map to be validated and assessed. The information obtained on the regional geomorphology clearly explains the special distribution of recorded mass movements, especially landslides.</p>