Rapid landslide hazard mapping in the Rio Minho watershed, Central Jamaica
Rafi Ahmad ( Unit for Disaster Studies, UWI) and Kevin Northmore ( DFID/British Geological Survey Landslide Hazard Assessment Project)
The north eastern part of Jamaica was subjected to intense rainfall over
two days in early January 1998, a possible manifestation of El Nino. Four people were killed by the resulting
landslides which also caused damage to housing,
infrastructure and agriculture estimated at US $5.6M.
The awareness of landslide hazards in Jamaica, and the need to mitigatetheir effects by incorporating appropriate hazard reduction measures into the planning process, is at last on the increase.
Following closely on the heels of the Kingston Metropolitan Area hazard mapping project, a further landslide hazard study is being undertaken by the University of the West Indies (UWI) in collaboration with the British Geological Survey (BGS) for the Rio Minho watershed area in central Jamaica. Using
assessment techniques developed in landslide-prone areas as far afield
as Papua New Guinea, Fiji and Slovakia, the Rio Minho project is
scheduled for completion by the end of 1999.
A Geographical Information System (GIS) database has been compiled of existing and newly acquired maps, remotely sensed imagery and other
information. The significance to landsliding of each factor theme has been
determined using spatial analysis, and a set of landslide hazard models
produced. Resulting landslide hazard maps will identify areas most
susceptible to slope failure and provide planners and other agencies
with the basic information needed to make sensible planning decisions to
enhance public safety and reduce economic loss.
The fact that over 50% of recent landslides in Jamaica occurred in areas
where slopes had previously failed shows that such maps, based on past
events, can help to predict the likelihood and severity of future
landsliding. This information is fundamental to the
implementation of cost-effective hazard mitigation measures.
An important
aspect of the project is the dissemination of the results through workshops and seminars to make
all interested parties aware of the project outputs. An additional aim is to establish how best the
information can be used by relevant government agencies and private
citizens for future planning and/or implementation of simple but
effective mitigation techniques.