Reducing landslide risk in communities: Evidence from the Eastern Caribbean

Landslide risk reduction measures have been undertaken in a number of vulnerable unplanned communities in the Eastern Caribbean. The communities are located on hillsides which are known to be susceptible to landslides. Physically-based modelling demonstrates that the construction of simple retaining walls, a common practice at the individual household level, is unlikely to be an effective method of landslide risk reduction. A more appropriate approach is shown to be the comprehensive management of all forms of surface water through the construction of a network of drains to capture surface runoff, household roof-water and grey water. With reference to three major rainfall events, evidence is given of landslide risk reduction having been achieved though the implementation of such hillslope drainage measures. This study provides important, rare evidence of the impact of an ‘on-the-ground’, community-based, approach to landslide risk reduction. From a policy point of view, it suggests that a community-based approach to landslide risk reduction may well be applicable to vulnerable communities in the developing world, and indicates how such an approach maybe initiated.

Research highlights
► Rare evidence of effectiveness of community-based landslide risk reduction.
► Scale of landslide mechanisms demands very localised ‘diagnosis’ of the hazard.
► Surface drainage often more effective in reducing landslide risk than retaining walls.
► Community knowledge combined with scientific methods leads to practical solutions.
► Strategic incrementalism approach enables delivery of physical mitigation measures.