Landslide hazard mapping: Jamaica case study. (WC/00/010).
This report presents specific results and findings from a case study in the Rio Minho, Jamaica, to develop a rapid, inexpensive method for the production of regional landslide hazard maps.
Conventional landslide hazard mapping involves expensive, time-consuming ground surveys and sub-surface investigations. It is essential for site specific studies that support new infrastructure development, but cannot be justified for wider regions. This report describes an alternative approach that does not provide site-specific information but instead depicts broad zones of hazard for a whole region. The resulting hazard maps do not show the actual hazard for any particular location, but they can be used as a guide to planning and to help select sites for detailed follow-up studies. The method is based on the principle that the past is the key to the future. It uses a landslide inventory for the study area that shows where landslides have already occurred. This is compared to a range of possible controlling factors, depicted in a series of thematic maps. The degree of control exerted by each factor, such as geology or elevation, is evaluated. The thematic maps are then reclassified in terms of landslide susceptibility and combined to produce the final hazard map.
This report is aimed at people and organisations in Jamaica that are concerned with, or affected by, landslides. It discusses local issues that affect the development of landslide hazard preparedness strategies in individual countries. The accompanying map is a first attempt at mapping the regional landslide hazard in this part of Jamaica.