Commentary on Guideline for landslide susceptibility, hazard and risk zoning for land use management

There have been examples of landslide susceptibility and hazard zoning in use since the 1970’s (e.g. Brabb et al., 1972; Nilsen, et al., 1979; Kienholz, 1978). The hazard and risk maps have usually incorporated the estimated frequency of landsliding in a qualitative sense rather than quantitatively. These examples of zoning have generally been used to manage landslide hazard in urban areas by excluding development in some higher hazard areas and requiring geotechnical engineering assessment of slope stability before development is approved in other areas. In some countries landslide susceptibility, hazard and risk maps are being introduced across the country. For example the PPR (Plans de Prevention des Riques Naturels Previsibles) in France and the Cartes de Dangers or Gefahrenkarten in Switzerland are carried out at the Canton level but with Federal funding support (Leroi et al., 2005).