Technical report on coastal erosion in Kiribati: visit to South Tarawa, 22 January - 10 February 1982

Abstract

Coastline movements are recognised as an important hazard on coral atolls by the Kiribati Government. Kiribati is spread over 3 million square kilometres of the Central Pacific and comprises 33 inhabited atolls of the Gilbert, Phoenix and Line Groups. This report concentrates on south Tarawa atoll (Fig. 1). The administrative and commercial centre of Kiribati is on south Tarawa atoll and located in Betio (port and government departments) , Bairiki (seat of Government) , Bikenibeu (main hospital/nurses training school, principal secondary school and sane government departments) and Bonriki (international airport) . The coastline and beaches of south Tarawa atoll are being modified by erosion and accretion. Tarawa, in common with many other atolls has a long coastline per unit area of land and since land areas are in short supply, even small changes in the coastline may be of considerable significance. Population density (Table 1) is high in south Tarawa, especially on Betio (20 per acre); and with limited natural resources, not only the land but also the lagoon and adjacent ocean areas are of prime concern to the Gilbertese people. Thus the consequences of changing sediment transport patterns particularly man—induced erosion that, for example, may result from building causeways, must be determined not only for the coastline but also for fishing and pollution of the lagoon environment.