Experts target landslides

Map to identify vulnerable areas being prepared

Jamaica Gleaner, 16 August 1998

 

By Janice Ansine, Staff Reporter

Local experts are trying to reduce the devastating effects of landslides on the lives and economy of communities across Jamaica.

So far, a landslide hazard map detailing 2,321 landslides in an area of 554 kilometres in Kingston, St. Andrew and St. Catherine, has been prepared by the Unit for Disaster Studies (UDS) at the University of the West Indies (UWI).

The map, guidelines on how to use it, and other information are being compiled into a disaster reduction manual which should be available next month, Rafi Ahmad, UWI geology lecturer and head of the UDS, told The Sunday Gleaner last week.

"This is a proactive response to landslide hazards and disasters, so that we will know what it is, know the science of it and have a record of the history of it; know what to do and then learn lessons from it and apply the lessons," Mr. Ahmad said.

This type of information, he added, is critical considering Jamaica’s vulnerability to landslides, and will help to identify areas where landslides are most likely to occur. Fitzroy Williams, director of housing in the Ministry of Environment and Housing told The Sunday Gleaner that the information will play a key role in planning housing developments.

Aim

Since the UDS was established four years ago, geologists at the UWI have been conducting research and compiling a database of information. Investigations have already been done on sections of parishes in central Jamaica. It is expected that others will soon be under way, with the overall aim of having detailed information on existing and potential areas for landslides across the island, Mr. Ahmad said.

Information from the UDS reveals that Jamaica’s two cities and many towns are in areas where landslides could occur. This, Mr. Ahmad said, was because for thousands of years, rainfall carried debris, such as dirt and gravel, down mountainsides. This then forms hilly slopes leading down to alluvial fans, which are flatter areas on which communities are gradually formed. These areas can therefore be prone to landslides.

"If we look at all the settlements in Jamaica a lot of slides are all over the place," Mr. Ahmad said. "…All our human settlements—Buff Bay, Orange Bay and Port Antonio, Montego Bay, Savanna-la-Mar, Kingston, all of the areas are located on alluvial fans…So we are in the way of a lot of natural landslides."

But this, Mr. Ahmad added, does not automatically mean that the area cannot be lived in. Hazard mapping is important to help determine the "degree of the relative hazard," he said. Settlements have existed for generations on some of these areas (alluvial fans), therefore there is a need for studies to understand the areas, determine how hazardous a landslide may be, in order to know how to deal with it, he went on.

Landslides are noted as being one of the major natural disasters that affect Jamaica, alongside flooding and hurricanes. Roads were damaged in sections of St. Andrew in January 1993, for example, after an earthquake triggered landslides. And over the years, landslides have caused periodic blockages of the Bog Walk Gorge in St. Catherine following heavy rains.

Frightened

More recently, landslides linked to heavy showers killed a young boy and frightened many residents in Hillside, St. Thomas. Also recently, four people were killed and others injured following a landslide in Portland. Property loss ran into millions of dollars.

But The Sunday Gleaner was unable to receive concrete data on damages and costs associated with landslides in Jamaica over any period of time. According to Paul Saunders, senior director mitigation, planning and research at the Office of Disaster Preparedness and Emergency Management (ODPEM), although landslides occur in Jamaica regularly and cause widespread damage, they are associated with other natural disasters. That makes it difficult to distinguish problems caused by landslides separately.