Landslide hazard zonation: A review of principles and practice

Of all natural hazards, slope failures are the most amenable to measures directed towards avoidance, prevention or correction. The causes inherent in the terrain are relatively well understood, hence the possibility of approaching landslide hazard mitigation from an areal zonal point of view. This publication gives the definitions and principles of landslides, and identifies causative conditions and processes (inherent or basic conditions, geology, geomorphology, hydrologic conditions and climate, vegetation, factors that change stress conditions and strength of materials). Investigation planning is described, including preliminary studies, techniques for identifying unstable and potentially unstable areas, e.g., remote sensing and ground studies, and individual factor maps. For the analysis of data, primarily cartographical methods, numerical rating of contributing factors and numerical-cartographical methods are outlined. Mention is made of some governmental and private responses to slope stability hazards. A summary of operational precepts closes the report. (TRRL)