Reducing groundwater vulnerability in Carbonate Island countries in the Pacific

Abstract

In the Pacifi c Ocean alone, there are about 1,000 populated, tropical and sub-tropical small islands. In many of these small island countries, because of the high permeability of their soils and regoliths, surface water is scarce or absent and groundwater is the main source of freshwater. The small land areas of these islands, typically of order 1 to 10 km2, coupled with rising per capita water consumption mean that the amount of freshwater available to island communities is often limited, particularly in the frequent El Niñ o-Southern Oscillation (ENSO)-related droughts that occur in the central and western Pacifi c. In addition, increasing population growth means that urban densities are often high, with some population densities exceeding 12,000 people/km2. Because of these densities and the added burden of domestic animals, particularly pigs, the quality of shallow groundwater is at risk of being polluted, as evidenced by high rates of deaths and diseases due to water-borne diseases in small island countries (WHO 2004).