Climatic and human influences on water resources in low atolls

Low, small islands have water supply problems amongst the most critical in the world. Fresh groundwater, the major source of water in many atolls, is vulnerable to natural and human-induced changes. Storm surges, droughts and over-extraction cause seawater intrusion. Settlements and agricultural activities can rapidly pollute shallow groundwaters. Limited land areas restrict freshwater quantities, which are especially vulnerable during frequent ENSO-related droughts. Demand for freshwater is increasing due to population growth and urbanisation. Water use for traditional crops often competes with water supplies for communities. This paper analyses the impact of frequent severe droughts on the quality and quantity of fresh groundwater in a low, atoll, Tarawa, in the Republic of Kiribati. We also examine the impacts of groundwater harvesting on traditional subsistence crops such as coconuts and of landuse on water quality. Strategies for reducing risks from climate variations and human impacts and increasing resilience are discussed.