WAEC SSCE - Geography - 1998 (Essay)

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(a) Ocean currents along the coast of Africa

• Canary Current (cold) - north-west coast
• Benguela Current (cold) - south-west coast
• Guinea Current (warm) - Gulf of Guinea, West Africa
• Mozambique/Agulhas Current (warm) - south-east coast

(Other acceptable currents: the cold Somali Current and the warm Somali Current during the monsoon reversal.)

(b) Effects of the two types of currents on the climate of Africa

Warm currents (e.g. the Mozambique/Agulhas Current):

• Raise the temperature of the coastal areas they wash, giving warmer conditions.
• Warm the air above them so it can hold more moisture, bringing rainfall to the adjacent coast (the south-east coast of Africa is well watered).

Cold currents (e.g. the Benguela and Canary Currents):

• Lower the temperature of the coastal areas, giving cool conditions.
• Cool the air above them so little moisture is released; this produces dryness and coastal deserts (the Namib Desert beside the Benguela Current and the aridity of the north-west coast beside the Canary Current). Cold currents also cause coastal fogs.

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(a) Explanation of atmospheric resources

Atmospheric resources are the useful materials and forms of energy provided by the atmosphere (the envelope of air surrounding the earth) which man can harness for his benefit. They include the gases of the air (oxygen, carbon dioxide, nitrogen), sunlight (solar energy), wind and precipitation (rainfall/moisture). They are largely free, renewable and available everywhere.

(b) Six uses of atmospheric resources (with examples)

• Sunlight for photosynthesis and solar power: Solar energy enables green plants to make food and is trapped by solar panels to generate electricity and to dry crops and clothes.
• Oxygen for respiration: Humans and animals breathe in oxygen to stay alive, and it is needed for combustion (burning of fuels).
• Carbon dioxide for plant growth: Green plants use carbon dioxide from the air during photosynthesis to manufacture their food.
• Nitrogen for soil fertility and industry: Nitrogen is fixed into the soil by lightning and bacteria to enrich it, and is used in making fertilizers and other chemicals.
• Wind as a source of power and transport: Wind drives windmills and wind turbines to pump water and generate electricity, and moves sailing boats; it also aids pollination and seed dispersal.
• Rainfall / moisture (water supply): Precipitation supplies water for drinking, farming (rain-fed agriculture and irrigation), rivers and hydro-electric power generation.

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(a) Four ways air transportation differs from water transportation

(b) Three major contributions of transportation to national development

• It moves raw materials to industries and finished goods to markets, boosting industry and trade.
• It opens up remote areas, encouraging farming, mining and even settlement of new regions.
• It promotes national unity and administration by linking different parts of the country and easing movement of people.
• It creates employment and generates revenue for the government.

(c) Three problems of water transportation in Tropical Africa

• Many rivers are interrupted by rapids and waterfalls, making them non-navigable for long stretches.
• Seasonal variation in water level: rivers become too shallow in the dry season and flood in the wet season.
• Silting and floating vegetation (water hyacinth) block channels and harbours.
• Few natural deep harbours, and inadequate modern port facilities and dredging.

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(a) Ways highlands promote economic development in the North Central Highlands (Jos Plateau region)

1. Mining: the highlands contain tin, columbite and other solid minerals whose extraction earns revenue and provides employment.
2. Cool, healthy climate: the higher altitude gives lower temperatures that attract settlement, tourism and resorts (e.g. Jos).
3. Temperate crop farming: the cool climate favours market gardening of vegetables, potatoes and fruits (Irish potatoes, cabbage).
4. Hydro-electric power and water supply: highland rivers provide sites for dams, water reservoirs and power generation.
5. Tourism and grazing: scenic landscapes attract tourists, while highland grasslands support livestock rearing.

(b) Characteristics of highlands that hinder development

1. Steep slopes and rugged relief make construction of roads, railways and buildings difficult and costly.
2. Thin, poor and easily eroded soils on the slopes limit large-scale crop farming.
3. Difficult accessibility isolates settlements and raises transport costs.
4. Rapids and waterfalls on highland rivers interrupt navigation.
5. Cold and misty weather at times, and the danger of soil erosion and landslides, discourage some activities.

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(a) Sketch map of Nigeria showing Rivers Kaduna, Cross and Ogun and their source areas

Key: ★ indicates the source area of each river. The rivers are shown by thick blue lines and labelled clearly.

(b) Characteristics of rivers in Nigeria

1. Many rivers have rapids and waterfalls, especially in their upper courses where they flow across highlands.
2. They have a seasonal regime: water level is high in the rainy season and low in the dry season.
3. Most rivers are short and swift-flowing, particularly those flowing from the eastern highlands to the coast.
4. Many have shallow channels and experience deposition, silting and the growth of water weeds in parts of their courses.

(c) Economic importance of rivers in Nigeria

1. They provide water for irrigation, especially for dry-season farming.
2. They are used for fishing and support fish processing and trade.
3. Navigable sections provide water transport for people and goods.
4. They provide sites for hydro-electric power generation, for example at Kainji, Jebba and Shiroro.

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The stem's "sorest" region is read as the forest region. The table below distinguishes agriculture in the forest and savanna regions of Nigeria.

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Explanatory notes (any two)

(a) Flood plain

A flood plain is the flat, low-lying land bordering a river on either side in its lower course, which is regularly covered with water when the river overflows its banks during floods. It is built up of fine sediment (alluvium) dropped by the river each time it floods, so it is very fertile. It is formed by the deposition of alluvium and the lateral (sideways) swinging of meanders, which widens the valley floor. Features found on it include levees, meanders, ox-bow lakes and marshes. Flood plains are valuable for farming (e.g. rice) and settlement. (Diagram: a river winding across a broad flat plain with levees and an ox-bow lake.)

(b) Hydrological cycle

The hydrological (water) cycle is the continuous circulation of water between the sea, the atmosphere and the land. Water evaporates from oceans, seas, rivers and lakes (and transpires from plants) to form water vapour. The vapour rises, cools and condenses to form clouds. The moisture falls back to the earth as precipitation (rain, snow, hail). Some water flows over the surface as run-off into rivers that return it to the sea, some sinks into the ground as infiltration/ground water, and the cycle repeats endlessly. The total amount of water on earth stays the same. (Diagram: sea, arrows for evaporation up, condensation to cloud, precipitation, run-off and infiltration back to sea.)

(c) River erosion

River erosion is the wearing away and removal of the bed and banks of a river channel by the moving water and its load. It takes place in four main ways: corrasion (abrasion) - the load rubs and grinds against the bed and banks; hydraulic action - the sheer force of moving water dislodges loose material; corrosion (solution) - the water dissolves soluble rocks such as limestone; and attrition - the load particles knock against one another and break into smaller pieces. Erosion may act vertically (deepening the valley, chiefly in the upper course) or laterally (widening it). It produces features such as V-shaped valleys, gorges, waterfalls, potholes and rapids. (Diagram: a V-shaped valley in the upper course with a waterfall.)

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(a) Map of Nigeria showing solid-mineral-mining towns and refinery towns

Key: ● Solid-mineral-mining town; ▲ Refinery town.

• Jos: tin and columbite
• Enugu: coal
• Itakpe: iron ore
• Refinery towns: Kaduna, Warri and Port Harcourt

(b) Contributions of solid minerals to the economy of Nigeria

1. They provide revenue to government through taxes, royalties, licence fees and export duties.
2. They earn foreign exchange when minerals are exported.
3. They provide employment and income for miners, transporters and workers in allied industries.
4. They supply raw materials to industries, for example iron ore for steel, limestone for cement and coal for industrial use.
5. They promote the development of roads, railways, electricity and other infrastructure in mining areas.
6. They encourage the growth of towns and trading activities around mining centres.

(c) Problems facing the mining of solid minerals in Nigeria

1. Inadequate capital for exploration and large-scale mechanised mining.
2. Low level of technology and shortage of modern mining equipment.
3. Inadequate skilled manpower, such as geologists, engineers and technicians.
4. Poor infrastructure, especially transport routes and electricity supply.
5. Illegal mining and illegal transactions in minerals.
6. Depletion or exhaustion of some mineral deposits.

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(a) Four ways in which urban settlements differ from one another

• Function: Settlements differ by their dominant role, for example industrial towns (Kano), administrative/capital cities (Abuja), commercial towns (Lagos), mining towns (Enugu) and port towns (Port Harcourt).
• Size of population: Some are large metropolitan cities of several million (Lagos) while others are small towns of a few thousand.
• Age and origin: Some are ancient, indigenous towns (Ibadan, Benin) while others are modern planned cities (Abuja).
• Site and situation/layout: Some have a planned grid layout with good facilities; others have grown haphazardly with a mixture of unplanned quarters.
• Level of development/infrastructure: Cities differ in the quality of roads, electricity, water and services they provide.

(b) Four ways in which rural settlements depend on urban settlements

• Market for produce: Rural areas sell their farm produce (food crops, livestock) to the urban centres.
• Supply of manufactured goods: Villagers obtain clothing, tools, fertilisers, machinery and other processed goods from the towns.
• Higher social services: Rural dwellers travel to towns for secondary/tertiary education, specialist hospitals, banking and administration.
• Employment and income: Urban centres provide jobs for rural migrants who often send money home (remittances).
• Processing and storage: Farm produce is processed and stored in urban factories and warehouses before final sale.

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(a) Shape of the earth

The earth is spherical (round) in shape, but not a perfect sphere. It is slightly flattened at the two poles and bulges at the equator; this true shape is described as an oblate spheroid (geoid).

(b) Four proofs that the earth is spherical

• Circumnavigation: Travellers and ships (from Magellan's voyage onward) who set out in one direction and keep going eventually return to their starting point without turning back, which is only possible on a round body. (Diagram: an arrow going right round a circle back to the start.)
• Ship on the horizon: As a ship approaches from over the sea, the top of its mast is seen first and then the hull; as it sails away the hull disappears before the mast. This is caused by the curvature of the earth's surface. (Diagram: ships at different points on a curved sea surface.)
• Circular shadow during a lunar eclipse: The shadow the earth casts on the moon during a lunar eclipse is always circular, and only a sphere casts a circular shadow in every position. (Diagram: sun, round earth and its round shadow falling on the moon.)
• The widening horizon / view from a height: The higher an observer climbs (a hill, an aircraft), the wider the circular horizon they can see, which shows the surface is curved. Photographs taken from space and aircraft also show the earth as a sphere. (Diagram: an observer at increasing heights with an expanding circular horizon.)

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(a)(i) Annual temperature range

Range = highest − lowest = \(23^{\circ}\text{C} - 12^{\circ}\text{C} = 11^{\circ}\text{C}\).

(a)(ii) Mean monthly temperature

Sum of temperatures \(= 23+22+20+17+15+12+13+16+17+19+20+22 = 216\). \[\text{Mean} = \frac{216}{12} = 18^{\circ}\text{C}.\]

(a)(iii) Total annual rainfall

\(200+180+120+45+8+0+0+0+5+35+100+160 = 853\ \text{mm}\).

(b)(i) Climatic region

The station lies in a Tropical wet-and-dry (Tropical Continental / Savanna) region.

(b)(ii) Two supporting reasons

• There is a marked single rainy season in the high-sun months (November to March, peaking at 200 mm in January) and a pronounced dry season with three completely rainless months (June, July, August), which is the classic savanna wet-and-dry rhythm.
• Temperatures are warm throughout the year (mean 18°C, all months above 12°C) with a fairly small range (11°C) and a high annual rainfall total (853 mm), all typical of the tropical continental belt.

(c) Hemisphere

The highest temperatures occur in December to February and the lowest in June to July, so the warm summer season falls in December to February. This places the station in the Southern Hemisphere.

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Characteristics and mode of formation (any two)

(a) Yardang

Characteristics: A yardang is a long, narrow, streamlined ridge of hard rock separated by grooves or troughs, found in hot deserts. The ridges run parallel to the direction of the prevailing wind and have a steep, blunt front facing the wind and a tapering tail. They may be several metres high.

Mode of formation: Yardangs are formed by wind erosion (abrasion and deflation). In a desert where soft and hard rocks lie side by side in bands parallel to the wind, the wind, armed with sand, wears away the softer bands into grooves, leaving the harder bands standing up as ridges. Abrasion is strongest near the ground, undercutting the ridges. (Diagram: parallel ridges and grooves aligned with the wind arrow.)

(b) Crater

Characteristics: A crater is a roughly circular, funnel-shaped or basin-shaped depression at the top (summit) of a volcano, surrounding the vent. It has steep inner walls and may hold water to form a crater lake. A very large crater formed by collapse or violent explosion is called a caldera.

Mode of formation: A crater is formed during volcanic eruption. As lava, ash and gases are blown out through the vent, material piles up around the opening, and the funnel-shaped mouth left at the top of the cone is the crater. Collapse of the summit into the emptied magma chamber, or a violent explosion, may enlarge it into a caldera. (Diagram: a volcanic cone with a bowl-shaped crater and central vent.)

(c) Block mountain (horst)

Characteristics: A block mountain is an upstanding block of land with steep fault sides and a fairly level top, bounded by roughly parallel faults. Examples include the Ruwenzori and the Vosges.

Mode of formation: It is formed by faulting. When the crust is subjected to tension or compression, cracks (faults) develop, and a middle block is left standing higher either because it is uplifted or because the blocks on either side subside (sink). The raised block is the block mountain (horst); a sunken block between faults gives a rift valley. (Diagram: a central up-thrown block standing above two down-thrown blocks bounded by faults.)

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(a) Location of vegetation belts and towns on an outline map of Africa

The Veldt is the warm-temperate grassland in the interior of South Africa; Johannesburg is a major town there. Mediterranean forest occurs in the north-western Atlas region and around the south-western Cape; Cape Town is within the Cape belt. The tropical grassland (savanna) forms broad belts north and south of the equatorial forest; Kano is a major town in the northern savanna belt.

(b) Characteristics of tropical grassland (savanna) vegetation

• It is dominated by grasses, commonly about \(2\) m high in wetter areas. The grasses are taller where rainfall is higher and become shorter and more sparse towards drier areas.
• The grasses are green and fresh in the rainy season, but become yellow or brown in the long dry season.
• Trees are scattered rather than forming a continuous forest. Typical trees include acacia, shea butter, locust bean and silk-cotton.
• Many trees are deciduous, shedding their leaves in the dry season to reduce water loss.
• Trees have drought-resistant features such as long tap-roots, thick bark and small leaves. Towards the driest margins, thorny bushes and scrub become more common.

(c) Importance of tropical grassland vegetation to people

• The grasses provide pasture for livestock such as cattle, goats and sheep.
• The relatively open vegetation makes land easier to clear and cultivate. Crops such as millet, guinea corn and groundnuts can be grown.
• Trees supply fuelwood, timber, fruits and useful products such as gum.
• The savanna supports wildlife, providing opportunities for game reserves and tourism.

Examination reminder: Link each savanna characteristic to the seasonal rainfall pattern: a wet season produces green, taller grass, while a long dry season leads to brown grass, deciduous trees and drought-resistant plant adaptations.

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(a) Why irrigation agriculture is more important in the Nile Basin than in the Niger Basin

1. Aridity of the surrounding land: the Nile flows through the Sahara and Egyptian desert where rainfall is almost nil, so crops depend entirely on irrigation, whereas the lower Niger Basin has enough rainfall for rain-fed farming.
2. Regular, predictable flood and flow: the Nile has a steady regime fed by equatorial and Ethiopian sources, and dams such as the Aswan give a controlled year-round water supply for irrigation.
3. Dense population and long history of irrigation: the Nile valley has ancient, well-developed irrigation systems and canals supporting a large farming population that has always relied on the river.

(b)(i) Other uses of the River Nile

1. Generation of hydro-electric power (Aswan High Dam).
2. Inland water transport and trade.
3. Fishing for food and income.
4. Domestic and industrial water supply, and tourism.

(b)(ii) Characteristics of the river which limit its usefulness

1. Cataracts and rapids interrupt navigation along parts of its course.
2. Seasonal variation in flow with periods of low water.
3. Heavy silting and sedimentation that clogs canals and reservoirs.
4. Evaporation losses and swampy sections (the Sudd) that waste water and hinder movement.

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(a) Factors which favour lumbering in Nigeria

1. Extensive tropical rain forest in the south with valuable hardwood trees such as mahogany, iroko, obeche and opepe.
2. Heavy rainfall and high temperatures that encourage rapid and continuous tree growth.
3. Rivers and roads that provide means of floating and transporting logs to sawmills and markets.

(b) Contributions of lumbering to the economy

1. Provides timber and wood for building, furniture and construction.
2. Supplies raw materials to saw-milling, plywood, paper and furniture industries.
3. Earns foreign exchange through the export of timber and wood products.
4. Provides employment and income for loggers, sawmill workers and traders.

(c) Problems facing lumbering

1. Mixed forests with valuable trees scattered among many worthless ones, raising the cost of extraction.
2. Dense undergrowth and difficult terrain that make felling and haulage hard.
3. Poor transport facilities from forest to market.
4. Shortage of capital and modern machinery for large-scale logging.
5. Deforestation and slow replacement of trees, plus pests and forest fires, threaten the resource.

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(a) Characteristics of manufacturing industries in Tropical Africa

• They are dominated by light industries such as food processing, textiles, soap and beverage production rather than heavy engineering.
• Most are primary/agro-based processing industries that add value to raw agricultural and mineral products (e.g. palm oil milling, cotton ginning).
• Industries are few, small-scale and unevenly distributed, concentrated in a few large towns, ports and capital cities.
• They rely heavily on imported machinery, spare parts and skilled expertise from outside the region.
• They are largely import-substitution industries producing consumer goods for the local market.

(b) Ways manufacturing industries contribute to economic development

1. Employment generation: they create jobs for skilled and unskilled labour, reducing unemployment.
2. Income and revenue: they raise workers' incomes and provide government revenue through taxes and duties.
3. Foreign exchange: exported manufactured goods earn foreign currency, while local production reduces import bills.
4. Value addition: they process raw materials into finished goods, raising the value of local resources.
5. Infrastructural growth: they stimulate development of roads, power and communication, and encourage growth of allied industries.

(c) Problems facing industrial development

1. Shortage of capital for investment and expansion.
2. Inadequate power supply and poor infrastructure (roads, water, communication).
3. Shortage of skilled manpower and low level of technology.
4. Small home market caused by low purchasing power and poverty.
5. Competition from cheaper, better-quality imported goods, and political instability.

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(a) Four processes of soil formation

• Weathering of parent rock: The breaking down of the underlying rock by physical, chemical and biological weathering produces the mineral particles that form the basis of the soil.
• Addition of organic matter (humification): Dead plants and animals decay and are broken down by micro-organisms to form humus, which is added to the mineral matter and enriches the soil.
• Leaching and eluviation: Rainwater passing down through the soil dissolves and washes soluble minerals and fine material from the upper layers down to the lower layers, helping to develop distinct soil horizons.
• Action of living organisms and climate: Burrowing animals (earthworms, termites), plant roots, and the effects of temperature and rainfall mix the soil, aerate it and speed up the chemical changes that continue soil development over a long time.

(b) Four ways soil is important

• It is the medium for plant growth, supplying anchorage, water and nutrients, and so is the basis of agriculture and food production.
• It provides pasture and grazing land for the rearing of animals.
• It supplies raw materials such as clay for pottery, bricks and building, and holds ground water.
• It supports forests and natural vegetation that provide timber and other products, and it is home to countless organisms that keep the ecosystem going.

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(a) Factors responsible for low volume of trade between Nigeria and other African countries

1. Similarity of products: most African countries produce and export similar primary raw materials (cocoa, coffee, minerals, oil), so they compete rather than trade with one another.
2. Low level of industrialisation: few countries produce the manufactured goods others need, so demand is met from Europe, America and Asia instead.
3. Poor transport and communication links: road, rail and shipping connections between African states are weak, making inter-country movement of goods slow and costly.
4. Different currencies and trade barriers: varying currencies, high tariffs, import duties and border restrictions discourage cross-border trade.
5. Colonial trade orientation: economies were built to trade with former colonial powers rather than with neighbours, a pattern that still persists.

(b) Ways of increasing the volume of trade

1. Industrialisation and product diversification so countries produce different goods that others need.
2. Improving inter-state transport such as the Trans-African highways, rail links and shipping services.
3. Strengthening economic groupings like ECOWAS and the African Continental Free Trade Area to remove tariffs and barriers.
4. Introducing a common currency or convertible payment systems to ease transactions.
5. Establishing common markets and joint ventures, and improving communication and trade information among member states.

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(a) Map of Africa

On an outline map of Africa, locate and name:

• (i) Rivers: the Nile (north-east, flowing to the Mediterranean), the Volta (Ghana, flowing to the Gulf of Guinea) and the Niger (West Africa, flowing to the Gulf of Guinea).
• (ii) Deltas: an inland delta - the inland Niger delta in Mali; and a coastal delta - the Nile delta (or the Niger delta).
• (iii) The Akosombo Dam on the River Volta in Ghana.

(A neat labelled sketch map is required.)

(b) Uses of the Akosombo Dam

1. Generation of hydro-electric power for Ghana and neighbouring countries (and for the Volta aluminium smelter).
2. Creation of Lake Volta, used for inland water transport.
3. Irrigation of farmland and provision of water supply.
4. Fishing on Lake Volta, and tourism/recreation.

(c) Problems facing hydro-electric power generation in Africa

1. Seasonal variation in river flow reduces output in the dry season.
2. Shortage of capital to build and maintain large dams.
3. Silting of reservoirs, high cost of transmission, and low demand in some areas.

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India has one of the most uneven population distributions in the world. Dense clustering occurs in the Ganges plain and along the coasts, while the mountains, deserts and dense forests are sparsely settled.

(a) Factors responsible for the distribution

• Relief: The extensive, low-lying and level Ganges (Indo-Gangetic) plain is easy to cultivate and build on, attracting dense settlement, while the high Himalayas and the Deccan uplands repel population.
• Fertile soils: The rich alluvial soils of the river plains support intensive farming and therefore large rural populations.
• Water supply and rainfall: Areas with reliable monsoon rainfall and river water (Ganges, Brahmaputra) are densely peopled, whereas the arid Thar Desert of the north-west is thinly settled.
• Industrial and commercial development: Cities such as Mumbai, Kolkata, Delhi and Chennai draw people through jobs in industry, trade and services.
• Transport and coastal advantage: Ports and good road/rail networks concentrate people along the coasts and river valleys.
• History and religion: Long-settled river valleys and holy cities along the Ganges have accumulated population over centuries.

(b) Advantages of dense population

• Large supply of cheap labour for agriculture and industry.
• Big internal market that encourages manufacturing and trade.
• Availability of skilled manpower and professionals for development.
• Cheaper provision of social services (schools, hospitals, roads) per person where people are concentrated.
• Strong defence and political influence from a large population.

(c) Problems of dense population

• Pressure on farmland leading to land fragmentation and low output per person.
• Overcrowding, slums and housing shortages in the big cities.
• Unemployment and under-employment.
• Strain on food supply, water, schools, hospitals and other social amenities.
• Environmental problems such as pollution, deforestation and poor sanitation.
• Widening poverty and high rural-urban migration.