JAMAICA: Hazards related to landslides are a major societal and environmental concern to Jamaica in general and the Kingston Metropolitan Area (KMA), in particular, which is the main centre of the economic and industrial activity of the country.
Recurrent landslide damage in KMA, caused specially by frequent rainstorms, should be a growing concern to
. . . (a) the policymakers and planning agencies,
. . . (b) Ministries of the government dealing with:
............... agriculture, transport, construction, housing and environment, health, security,
. . . (c) Parish councils,
. . . (d) Public utilities including water,
. . . (e) Electricity and Telecommunications,
. . . (f) Farmers,
. . . (g)Tourism interests, - and the
. . . (h) General public.
It has been estimated that throughout the Caribbean some US$15m is spent annually to repair the landslide damage to roads (DeGraff et al., 1989).
Geological instabilities prevail over large sections of KMA. Many residential areas and infrastructure in KMA are located on large ancient landslides, and it is a common observation that new landslides have occurred on slopes that had previously failed.
However, the real-world situation is that such small island states as Jamaica, have a limited land area which in spite of its natural constraints, must be utilized to meet the needs of their peoples.
The land area of Jamaica is some 11,000 km2, with about 80% of the slopes being above 200 , and a population density of 219 persons/km².
In KMA, which represents some 5% of the islands total area, the average population density is about 1264 persons / km² and it hosts some 57% (approx. 700,000 persons) of Jamaica's total urban population.
In this scenario the management of landslide hazard is especially important, and is also difficult and challenging.
The answers lie in learning from the past examples of landslides that have occurred in KMA for thousand of years, in finding out why these landslides occurred and what was the direct and indirect damage they caused.
Examples of some of these events have been presented with the aim of making planners, decision-makers, engineers, and public aware of the geological sensitivity of the terrain.
Much of the landslide damage during the last 40 years appears to have occurred on slopes that have been modified for human use.
The present-day landslide hazard is therefore symptomatic of changing landuse.
" If human activities can cause or aggravate the destructive effects of landslides, they can also be used to eliminate or reduce them".
It is important that strategies be formulated and implemented to
(a) reduce losses from landslides, and
(b) restrict development in more dangerous areas that are prone to landsliding.
Pro-active strategies of loss-reduction should be implemented in the planning stages of all new development projects.
A SUCCESSFUL LANDSLIDE LOSS REDUCTION PROGRAMME IS POSSIBLE ONLY THROUGH THE ACTIVE PARTICIPATION AND COOPERATION OF BOTH THE CITIZENS AND THE ELECTED AND APPOINTED OFFICIALS OF THE GOVERNMENT.
The very first step in loss-reduction is the availability of landslide susceptibility maps.