GIS and Remote Sensing Assessment of Landslide Susceptibility along the Cameroon Volcanic Line: West Region, Cameroon

Abstract

The physical and tectonic setting exposes the western part of Cameroon to natural and anthropogenic hazards. Small scale landslides with devastating effects are recurrent along the Cameroon Volcanic Line. Limited studies have addressed the susceptibility to sliding in the area. This study therefore aimed at producing a landslide susceptibility map of the West Region to aid local and national authorities in land use planning and policy to minimise loss. Eleven conditioning and triggering factors were selected to investigate landslide susceptibility in the study area. These factors include; slope angle, lithology, soil, slope aspect, elevation, rainfall, geological faults, land use, normalised difference vegetation index, roads and river networks. These factors were assigned weights using the analytical hierarchy process. The weighted linear combination technique was used to derive landslide susceptibility indices and the susceptibility map. The map was reclassified into five classes; very low, low, moderate, high and very susceptibility class. About 16% (2180 km2) of the study area lies within the high to very high class while 47% (6512 km2) is found within the moderate class. Steep slopes, weathered volcanic rocks and thick soil cover at high elevations control the distribution of landslides while high intensity rainfall is the main triggering factor. Residential houses and road infrastructures along steep slopes are the most vulnerable to sliding. Site specific assessment needs to be conducted in order to implement effective mitigation measures.