Assessing soil susceptibility to mass movements: Case study of the Coello river basin, Colombia

Abstract

Mass movement susceptibility and hazard maps are essential tools for mitigation and prevention of landslides. The upper Coello river basin in the Colombian Andes is a catchment where the conjunction of high rainfall, steep slopes, and unstable volcanic ash cover, among other factors, causes frequent mass movements. A qualitative causal model was developed using detailed geopedologic information collected in sample areas and validated outside for mass movement hazard zoning. It highlights the relationships between mass movement-promoting soil properties (mainly mechanical and physical) and resulting morphodynamic processes and features (mainly landslides, various solifluction forms, and terracettes). Soil properties were assessed in terms of their susceptibility to mass movements from an integrated soil-geomorphic map.