Coastal change: it's implications for Eastern Africa

Abstract

The coastal region of East Africa and the Western Indian Ocean encompasses the coastlines of four mainland countries extending from Somalia in the Horn of Africa through Kenya and Tanzania to Mozambique in the south, as well as five island nations, including the Seychelles,' the Comoros, the Mauritius, Reunion and Madagascar (Fig. 1). Together, these countries have 12,000 kilornctr cs of coastline and a rapidty growing population of about 55 million (UNEP, 1988, 1989; Granlund, 1994). The coastline of East Africa is an area of great physical beauty, rich in living resources. Palm-fringed beaches of white coral sand lead down to tranquil lagoons, enclosed by spectacular coral reefs with their wealth of eolourful fish, shells and coral. The coastline has vast Mangrove forests, high cliffs, wide stretches of sand dunes and numerous offshore and oceanic islands (UNEP, 1989). Along the shorelines of East Africa and the Island states of the Western Indian Ocean, however: coastal change is a common problem damaging or threatening tourism and communication infrastructure. Coastal change as it occurs in the' region, is usually caused by natural changes in the prevailing condition of sedimentation along the shore, or as a result of human interference with coastal sedimentation systems. The usual causes of coastal change in the region include coastal erosion, sediment accretion and coastal reclamation. The latter is commonly carried out in the Island States where land is at a premium. This usually involves filling of wetlands and other, lowlands to create new land area for construction. In the Seychelles, for example, this .method was used to reclaim large areas where the airport and Port Victoria are built (Odada, 1993). In many countries of the region, the rate of coastal erosion, or in the case of Malindi in Kenya, of sediment accretion and the resulting environmental degradation and economic loss in on such a scale alarming.