(a) Draw a sketch map of Africa and on it mark and... | WAEC SSCE - Geography - 1989 (Essay)

Question 1 Report

(a) Draw a sketch map of Africa and on it mark and name the following dams:
(i) Kariba
(ii) Aswan
(iii) Cabora Bassa
(iv) Akosombo
(v) Owen

(b) With reference to specific examples in Africa, discuss the importance of hydro-electric power projects to the economy

Answer

The outline of the continent is drawn and each dam is marked with a solid dot (●) at its correct position on the river named, then labelled:

Aswan Dam – on the River Nile in southern Egypt (north-east Africa).
Owen Falls Dam – on the River Nile where it leaves Lake Victoria, at Jinja in Uganda (East Africa).
Akosombo Dam – on the River Volta in Ghana (West Africa).
Kariba Dam – on the River Zambezi, on the Zambia–Zimbabwe border (south-central Africa).
Cabora Bassa Dam – on the River Zambezi in Mozambique (southern Africa).

With reference to specific African examples:

Provision of electricity for industry: cheap, reliable power drives manufacturing, e.g. the Akosombo Dam on the Volta supplies the VALCO aluminium smelter at Tema in Ghana, so bauxite can be refined locally.
Domestic and urban power supply: HEP lights homes, offices, schools and hospitals, raising the standard of living, e.g. Owen Falls (Nalubaale) supplies much of Uganda and exports power to Kenya.
Irrigation and water supply: the reservoirs store water for farmland, e.g. Lake Nasser behind the Aswan High Dam irrigates the Nile valley and permits double-cropping.
Flood control: the dams regulate river flow and reduce destructive downstream flooding, e.g. Aswan on the Nile and Cabora Bassa on the Zambezi.
Fishing: the large artificial lakes support commercial fisheries, e.g. Lake Volta and Lake Kariba, providing food and income.
Tourism and recreation: the lakes and dam walls attract visitors, generating revenue, e.g. Lake Kariba resorts.
Water transport (navigation): the calm reservoirs serve as inland waterways, e.g. boat services on Lake Volta linking northern and southern Ghana.
Employment and revenue: construction and operation create jobs and the sale of power earns government revenue.

High cost of construction: dams need enormous capital that poor countries lack, forcing reliance on foreign loans and aid.
Seasonal variation in river flow / water shortage: reduced discharge in the long dry season lowers the water level and disrupts power output.
Silting of reservoirs: sediment carried by rivers fills the reservoir, reducing storage capacity and shortening the dam’s life.
High cost of resettlement: flooding large areas displaces people (e.g. over 80,000 resettled for Lake Volta), which is costly and socially disruptive.
Shortage of skilled labour and technical expertise for building, running and maintaining the plant.
Mechanical failure and poor maintenance of turbines and equipment interrupt supply.
Low or scattered demand: a small, dispersed population makes projects uneconomic and long transmission lines expensive.
Water-borne diseases: the still reservoir water breeds bilharzia (schistosomiasis) and mosquitoes (malaria).
High evaporation losses from the reservoirs in the hot tropical climate reduce the volume of water available.

Answer Details

The outline of the continent is drawn and each dam is marked with a solid dot (●) at its correct position on the river named, then labelled:

Aswan Dam – on the River Nile in southern Egypt (north-east Africa).
Owen Falls Dam – on the River Nile where it leaves Lake Victoria, at Jinja in Uganda (East Africa).
Akosombo Dam – on the River Volta in Ghana (West Africa).
Kariba Dam – on the River Zambezi, on the Zambia–Zimbabwe border (south-central Africa).
Cabora Bassa Dam – on the River Zambezi in Mozambique (southern Africa).

With reference to specific African examples:

Provision of electricity for industry: cheap, reliable power drives manufacturing, e.g. the Akosombo Dam on the Volta supplies the VALCO aluminium smelter at Tema in Ghana, so bauxite can be refined locally.
Domestic and urban power supply: HEP lights homes, offices, schools and hospitals, raising the standard of living, e.g. Owen Falls (Nalubaale) supplies much of Uganda and exports power to Kenya.
Irrigation and water supply: the reservoirs store water for farmland, e.g. Lake Nasser behind the Aswan High Dam irrigates the Nile valley and permits double-cropping.
Flood control: the dams regulate river flow and reduce destructive downstream flooding, e.g. Aswan on the Nile and Cabora Bassa on the Zambezi.
Fishing: the large artificial lakes support commercial fisheries, e.g. Lake Volta and Lake Kariba, providing food and income.
Tourism and recreation: the lakes and dam walls attract visitors, generating revenue, e.g. Lake Kariba resorts.
Water transport (navigation): the calm reservoirs serve as inland waterways, e.g. boat services on Lake Volta linking northern and southern Ghana.
Employment and revenue: construction and operation create jobs and the sale of power earns government revenue.

High cost of construction: dams need enormous capital that poor countries lack, forcing reliance on foreign loans and aid.
Seasonal variation in river flow / water shortage: reduced discharge in the long dry season lowers the water level and disrupts power output.
Silting of reservoirs: sediment carried by rivers fills the reservoir, reducing storage capacity and shortening the dam’s life.
High cost of resettlement: flooding large areas displaces people (e.g. over 80,000 resettled for Lake Volta), which is costly and socially disruptive.
Shortage of skilled labour and technical expertise for building, running and maintaining the plant.
Mechanical failure and poor maintenance of turbines and equipment interrupt supply.
Low or scattered demand: a small, dispersed population makes projects uneconomic and long transmission lines expensive.
Water-borne diseases: the still reservoir water breeds bilharzia (schistosomiasis) and mosquitoes (malaria).
High evaporation losses from the reservoirs in the hot tropical climate reduce the volume of water available.