Guinea Current Case Study-Coastal Erosion

Ghana, West Coast Africa

1961 Akosombo Dam was constructed by the Americans

provided HEP and employment

Problem?

Togo, Benin, Keta, Kpeme, Tropicana, Lome all at peril of erosion

This is not aided by the 1300m break water at Lome which traps any sediment carried, leaving Benin and Kpeme to face severe destruction.

How?

Sediment became trapped by the dam and so there was no fresh supply of fluvial sediment entering the Estuary of the Volta Rova.

Guinea Current able of transporting 1.5 MILLION M3 of sediment per year

therefore lack of a supply means the currents erosive power increased along the coast.

So areas such as Togo and Benin etc, are at risk because there is no supply to act as a natural defence

Will cost £1-2 million for 1km sea defence

Countries being affected are unable to generate funds for such a scheme

Ghana will not pay- they are not in best financial position to pay for the damage

American's believe they have created employment and provided electricity so shouldn't have to pay

Causes

The Dam (direct)

Estuary of Volta Rova (indirect)

Guinea Current carries 1.5 million m3 of sediment per year (direct)

Deep Water port @ Lome

Effects

uncovered sandstone but the barrier at Lome affects depostion

Eroding 2000 km of coastline between the ivory coast and Nigeria

Keta has been severly damaged and there is now little left of the place

1300m break water at Lome has trapped sediment

1984 in 24 hours 100m of coastal road was lost- money was spent on redevelopment :(

'78-83 Tropicana-famous for tourism- lost 100m inland- Tourism is the main source of their capital

Kpeme improtant for it phosphourus supplies-accounts for over 1/2 of foreign exchange in Kpeme- is currently being protected by boulders

Benins oil wells are at risk

plans for penerpendicular coastal defence at Kpeme

however fears that Anoeh further along coastline would be at risk which is another £1-2 million