Coasts Of West Africa example essay topic

International Coastlines: The Care Of West Africa Why is there an erosion problem in West Africa? Most of the West African coast made up of a shallow, sandy coast over which breaking waves crash daily. Long beaches separate the shoreline from the sea. The coast consists of large stretches of sand embankments created by sand blown on shore, which have closed off and separated from the shore a chain of lakes, lagoons and mangrove swamps. These lakes and lagoons are areas of water enclosed by sand bars deposited by longshore drift.

The area is prone to storms, but the fetch some 4000 km to south America- means that high waves easily erode the fines sands of the coastal bed almost permanently. These are driven by almost permanent on-shore winds that blow across the Gulf of Guinea. In both January and July, monsoon winds blow on-shore from the southwest creating a series of waves that establish a year-round current from west to east. Few natural harbours or bays exist in the African continent, and along the coasts of West Africa, harbours built to encourage and support economic expansion have been artificial. This is part of the coastal erosion problem.

Economic development in the 1960's and since has been dependent on the creation of artificial ports such as Tema and Takoradi in Ghana designed to accommodate ships that can reach in-shore by means of dredged channels. The problem is therefore one of rapid erosion of sands. Keta Keta is located on the eastern edge of the Volta River Delta, to the east of a major shoreline sediment delta called Cape St. Paul. Erosion is occurring at Keta because sand moving from west to east by longshore drift - which shifts up to 1 million cubic meters each year - is deposited first at the Cape. This creates a sediment deficit in Keta, where the shoreline is retreating at rates of up to 8 m per year.

Its rate of movement is too slow to save it and adjoining towns from erosion, hence the necessity for the sea defence project. The effect of sustained erosion shown in Figure 9.6 has meant loss of property and the major road between Keta and Togo. Keta is now decimated in size, and the fishing industry has been destroyed. Investigating costal ecosystems In Dorset the natural ecosystem is being disturbed by human activity, though in this case, largely from tourism. The salt marsh ecosystem at Aln mouth Bay in Northumberland, shows how plant and animal communities develop over time along and around estuaries. Many salt marshes have been lost to industrial and port developments, such as those at Teesside and along the Thames estuary.

Studland Health, Dorset Studland Beach stretches for about 6 km southeast from the entrance to Poole Harbour in Dorset. It is owned and managed by the National Trust. Extensive sand dunes have formed at the back of the beach. Although owned by the National Trust, it is managed by English Nature.

In summer it is popular with visitors.