WAEC SSCE - Geography - 2003 (Essay)

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(a)(i) Enlarging square ABCD to twice its size

Divide the original square ABCD into a grid of equal small squares. Draw a new square whose sides are twice as long, giving an outline of \(18\,\text{cm}\) by \(18\,\text{cm}\), and rule the same grid on it so that each small square is doubled in side. Copy the detail from each small square of the original into the corresponding enlarged square, keeping the same relative positions.

(a)(ii) New scale

(b) On the enlarged outline, mark and name, using the correct conventional signs: (i) the two main roads; (ii) the settlement of Egbe; (iii) a spot height.

(c) From the contour lines, identify the land lying below 1000 ft and shade that area evenly.

(d) Three man-made features along the minor road between Oda Pete and Ogga

• The settlement of Omi.
• The school at Oda Pete.
• Footpaths and farmlands (a minor road junction is also present).

(e) Influence of relief on the location of settlements

• There are no settlements on the hilly areas because of the difficulty of building and movement.
• Settlements are located in the pass between two highland areas, for example between Ogbe and Egbe, and in the lowland areas.
• There is no settlement on the crest of the north-south ridge because of its ruggedness.
• Settlements are located on the gentle slopes, for example Oda Pete, Omi and Ogga.

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(a) Crude-oil-producing areas and towns in Africa

• Nigeria: Niger Delta; town: Port Harcourt.
• Algeria: Hassi Messaoud area in the Sahara; town: Hassi Messaoud.
• Libya: Sirte Basin; town: Marsa el Brega.

(b) Economic importance of crude oil to Nigeria

1. Crude oil is a major foreign-exchange earner. Exporting oil brings money into Nigeria from other countries.
2. It provides substantial revenue to the government through oil sales, taxes and royalties. This money can be used for public services and development projects.
3. It creates employment in exploration, drilling, refining, transport, marketing and related services. It also supplies energy and raw materials for industries such as petrochemical and plastics industries.

(c) Problems facing crude-oil production in Nigeria

1. Oil spillage and environmental pollution: leaks from wells, pipelines or tankers pollute land and water, damaging farmland, fishing grounds and settlements in the Niger Delta.
2. Vandalism, sabotage and conflict: damage to pipelines and conflict between local communities and oil companies can interrupt production and cause further spills.
3. Fluctuating world oil prices: when the world price of crude oil falls, oil exports earn less income, making production and government planning less secure.

Examination reminder: For the map question, place each oil area in the correct country and label both the producing area and a town clearly. For the written parts, give three separate, explained points rather than repeating the same idea as “income,” “revenue” and “money.”

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(a) Four types of atmospheric resources

• Sunlight (solar energy / insolation).
• Wind (moving air).
• Rainfall / water vapour (moisture).
• Air itself (its gases, chiefly oxygen, carbon dioxide and nitrogen).

(b) Usefulness of any two of the resources

1. Sunlight (solar energy):

• It provides light and warmth that make the earth habitable and drive the weather.
• It is essential for photosynthesis, by which green plants make food, so it is the basis of all agriculture and food chains.
• It is harnessed as solar energy for heating, drying crops, and generating electricity through solar panels.

2. Wind (moving air):

• It is used to generate power through windmills and wind turbines for pumping water and producing electricity.
• It drives sailing vessels and aids ventilation and the drying of crops and clothes.
• It aids pollination and seed dispersal of plants and transports moisture that brings rainfall.

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(a) Climate regions and towns in Africa

(b)(i) The vegetation associated with the tropical continental climate is tropical grassland, also called savanna.

(b)(ii) Savanna vegetation is adapted to the long hot dry season in the following ways:

• Many plants grow long tap roots or deep, durable root systems that reach water deep below the ground during the dry season.
• Some plants develop fleshy stems which store water for use when rainfall is scarce.
• Trees may have thick bark or thick leaves, helping to reduce water loss and protect the plant in hot, dry conditions.
• Leaves may be small, leathery or needle-shaped, giving a smaller surface area and reducing transpiration.

Examination point: Link each adaptation to water shortage in the dry season: roots obtain water, fleshy stems store it, and reduced or protected leaves limit water loss by transpiration.

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(a)(i) Explanation of settlement

A settlement is any place where people live, ranging from a single dwelling to a large city, together with the buildings and structures they use for shelter and other activities. It is a place where human beings have established their homes and carry on their daily life.

(a)(ii) Two major types of settlement

• Rural settlement (villages and hamlets, mainly agricultural).
• Urban settlement (towns and cities, mainly non-agricultural).

(By pattern they may also be grouped as nucleated/compact or dispersed/scattered.)

(b) Four factors that influence the location of settlements

• Water supply: people settle near rivers, springs, lakes and wells (wet-point sites).
• Relief: flat, gently sloping and well-drained land is preferred; steep slopes and flood-prone or marshy ground are avoided (dry-point sites).
• Fertile soil: good farmland attracts settlement because it supports food production.
• Others: availability of minerals, good transport routes, security/defence, and a favourable climate.

(c) Four functions of settlements (with examples)

• Administrative / political function - seat of government, e.g. Abuja.
• Commercial / trading function - major markets and business centres, e.g. Lagos, Onitsha, Kano.
• Industrial / mining function - manufacturing or mining towns, e.g. Warri (oil), Jos (tin mining).
• Educational / religious function - university or religious centres, e.g. Ile-Ife, Mecca, Jerusalem. (Others include port, tourist and residential functions.)

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(a) Five characteristics of manufacturing industries in Tropical Africa

• They are mostly light, consumer-goods and processing industries (food, drinks, textiles, soap) rather than heavy industries.
• Many are agro-based / raw-material based, processing local farm and mineral products for local use or export.
• They are few, small-scale and unevenly distributed, concentrated in a few large towns and ports (e.g. Lagos, Nairobi).
• They rely heavily on imported machinery, spare parts, capital and technical expertise from developed countries.
• They employ relatively low levels of technology and are largely foreign-owned or dependent on foreign investment, producing mainly for the home market.

(b) Five problems facing manufacturing industries in Tropical Africa

• Shortage of capital for establishing and expanding industries.
• Inadequate infrastructure - unreliable electricity, poor roads and water supply raise costs and disrupt production.
• Shortage of skilled manpower and technology, forcing dependence on expensive foreign experts and imported equipment.
• Small home market and low purchasing power of the largely poor population, limiting sales.
• Competition from cheap imported goods, together with shortage of quality raw materials and political instability, which discourage investment.

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(a) Outline map of Nigeria showing cattle rearing and movement

The principal cattle-rearing zone is the Sudan/Sahel savanna belt of northern Nigeria. The map shows Sokoto, Kano and Maiduguri within this zone, and a south-westward arrow indicating movement of cattle from the northern rearing zone to Lagos, a major consuming area.

(b) Problems of cattle rearing in Nigeria

1. Dry-season shortage of pasture and water: rainfall is low and seasonal in the far north; pasture dries up and water sources may fail during the long dry season.
2. Pests and diseases: ticks, tsetse flies and diseases such as trypanosomiasis, rinderpest and foot-and-mouth disease cause illness, deaths and reduced productivity.
3. Poor facilities and management: there are inadequate ranches, grazing reserves, veterinary services, capital, transport and cold-storage facilities. Long trekking also causes weight loss and may lead to clashes with farmers and cattle rustling.

(c) Measures being taken to solve the problems

1. Grazing reserves and ranches are being developed, with improved pasture, fodder cultivation, boreholes, dams and irrigation to provide dry-season water and feed.
2. Veterinary clinics, vaccination programmes, disease surveillance and control of ticks and tsetse flies are being provided. Cross-breeding is also used to obtain healthier and more productive animals.
3. Extension services educate herders on modern animal management, while loans and other financial assistance support ranch development.
4. Feeder roads, cattle trucks and rail transport reduce long-distance trekking. Refrigerated vehicles, abattoirs and cold stores help preserve meat and dairy products.
5. Designated grazing routes and reserves, together with security measures, help reduce farmer-herder conflict and cattle theft.

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Traversing

Traversing is a surveying method in which a series of connected straight lines is measured. For each line, the surveyor records its length and its bearing (direction measured clockwise from north). These measurements are then plotted to scale to show the route or boundary.

Plotting the traverse (scale: 1 cm represents 50 m)

Divide each ground length by 50 to obtain the plotted length. Starting at A, draw AB as 2.0 cm on a bearing of \(70^\circ\). From B, draw BC as 7.0 cm on a bearing of \(120^\circ\). Continue with CD, 2.4 cm on a bearing of \(85^\circ\), and DE, 1.5 cm on a bearing of \(55^\circ\).

Distance between A and E along the traverse line

The words “along the traverse line” mean the total distance travelled from A to E through B, C and D, not the straight-line distance from A to E.

\[AE = AB + BC + CD + DE\]

\[AE = 100 + 350 + 120 + 75 = 645\text{ m}\]

Therefore, the distance from A to E along the traverse is 645 m.

The straight-line distance between A and E would be a different measurement. It can be found from the completed scale drawing or by resolving bearings, and is approximately \(585\text{ m}\); however, this is not what “along the traverse line” asks for. In an examination, add the lengths of all traverse legs whenever the question asks for distance along the route.

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(a) Two differences between the Greek and Koppen systems

(b) Four major features of Koppen's system

• It uses quantitative data - fixed values of temperature and rainfall to define each type.
• It uses a system of letter symbols (A, B, C, D, E, plus small letters) for the main groups and sub-groups.
• It links each climate with its natural vegetation.
• It recognises five main climatic groups: A (tropical rainy), B (dry), C (warm temperate), D (cold temperate) and E (polar).

(c) Four features of the Tropical Rainforest (Equatorial, Af) climate

• High and uniform temperatures throughout the year, averaging about \(27^\circ\text{C}\), with a very small annual range (about \(2-3^\circ\text{C}\)).
• Heavy rainfall all year round, over 1500-2000 mm, with no real dry season (every month exceeds 60 mm).
• High relative humidity (often above 80 per cent) and heavy convectional rainfall, usually in the afternoons.
• Double rainfall maxima associated with the twice-yearly overhead sun, and generally still, calm air (the doldrums) with dense evergreen forest.

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(a) Fishing areas and towns in Nigeria

The map shows two inland fishing areas: the Lake Chad basin, with Baga as an important town, and the River Niger–Benue floodplain, with Lokoja. The Lagos offshore waters in the Gulf of Guinea are shown as an off-shore fishing area, with Lagos as the town.

(b)(i) Three methods of fishing in Nigeria

• Fishing with nets, such as cast nets, gill nets or seine nets.
• Fishing with hooks and lines.
• Using traps or baskets.

(b)(ii) Four types of fish caught

• Tilapia
• Catfish (mudfish)
• Mackerel
• Croaker

(c) Three benefits of fishing to the Nigerian economy

• It supplies protein-rich food for the population.
• It provides employment and income for fishermen, fish processors, traders and transporters.
• It provides raw materials for fish-processing industries and generates government revenue and trade.

Examination reminder: On a map question, place each fishing area in its correct broad location, then add the required town beside it. For inland fishing, choose rivers, floodplains or lakes; for off-shore fishing, place the area in the Atlantic coastal waters.

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(a) What are sedimentary rocks?

Sedimentary rocks are rocks formed from the accumulation, compaction and cementation (lithification) of sediments, that is, particles of older rocks, mineral matter or the remains of plants and animals, usually deposited in layers or strata by water, wind or ice.

(b) Three classes according to mode of formation

• Mechanically-formed (clastic) sedimentary rocks - e.g. sandstone, conglomerate, shale.
• Chemically-formed sedimentary rocks - e.g. rock salt, gypsum, some limestones.
• Organically-formed (biogenic) sedimentary rocks - e.g. coal, chalk, coral limestone.

(c) Description of one class - Mechanically-formed sedimentary rocks

These are formed from fragments (detritus) of pre-existing rocks that have been broken down by weathering and erosion. The particles are transported by rivers, wind or ice and deposited in layers. Over time the weight of overlying material compacts them and mineral cement binds the grains together. They are classified by grain size: coarse (gravel forming conglomerate), medium (sand forming sandstone) and fine (mud and clay forming shale). They are typically arranged in visible strata (bedding planes).

(d) Four ways sedimentary rocks are important to man

• They are the main source of fossil fuels - coal, crude oil and natural gas.
• They yield valuable minerals and building materials such as limestone (for cement), sandstone, clay, gypsum and rock salt.
• They form fertile soils and often contain underground water (aquifers) used for water supply and agriculture.
• They preserve fossils that help geologists in the study of earth history and in the search for petroleum and other resources.

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(a) Outline map of Africa

(b) Position and size of Africa in relation to other continents

Position

• Africa lies almost centrally between the other continents and is almost bisected by the Equator into Northern and Southern Africa.
• It lies approximately between latitudes 37°N and 35°S, and longitudes 15°W and 51°E. The meridian of about 20°E nearly divides it into eastern and western parts.
• It is bounded to the north by the Mediterranean Sea, which separates it from Europe.
• To the north-east it is bounded by the Red Sea and Gulf of Aden, which separate it from Asia. Africa is connected to Asia at the Isthmus of Suez.
• It is bounded by the Atlantic Ocean to the west and by the Indian Ocean to the east and south-east.
• It is the most tropical continent because about three-quarters of its land area lies between the Tropics of Cancer and Capricorn.

Size

• Africa is the second-largest continent after Asia.
• It has an area of about 30 to 31 million km², approximately one-fifth of the world’s land surface.
• It is about two-thirds the size of Asia and is larger than Europe, North America, South America and Australia.
• It extends for about 8,000 km from north to south and about 7,000 km from east to west.

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(a)(i) Definition of drought

Drought is a long, continuous period of abnormally dry weather, marked by a serious shortage of rainfall well below the normal amount for an area, leading to acute scarcity of water for plants, animals and human beings.

(a)(ii) Two areas affected by drought

• The Sahel region of West Africa (e.g. northern Nigeria, Niger, Chad, Mali).
• The Horn of Africa / East Africa (e.g. Ethiopia, Somalia, Kenya).

(b) Three effects of drought

• Crop failure and famine: Lack of rain causes crops to wither and die, leading to food shortage, hunger and even death.
• Death of livestock and loss of grazing: Pasture and water dry up, so animals die, ruining the pastoralists' livelihood.
• Water shortage and desertification: Rivers, wells and reservoirs dry up, the land becomes bare, soil erosion increases and the desert advances (desertification), forcing migration of people and animals.

(c) Three ways drought can be reduced

• Afforestation and control of desertification by planting trees and shelter belts to check wind erosion and improve rainfall.
• Construction of dams, boreholes and irrigation schemes to store water and provide it during dry periods.
• Water conservation and good land-management practices such as controlled grazing, mulching and prevention of bush burning, together with cloud seeding and public enlightenment.

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(a) Explanation of salinity

Salinity is the degree of saltiness of sea or ocean water, that is, the total amount of dissolved mineral salts (chiefly sodium chloride) present in a given quantity of water. It is usually expressed in grams of salt per 1000 grams of water (parts per thousand, \(\text{ppt or } ‰\)). The average salinity of the oceans is about \(35‰\) (35 grams per 1000 grams of water).

(b) Three factors causing variations in salinity

• Rate of evaporation: Where evaporation is high (hot, dry tropical and enclosed seas), water is removed but salt is left behind, so salinity is high (e.g. the Red Sea and the Dead Sea). Where evaporation is low, salinity is lower.
• Amount of fresh water added: Heavy rainfall, the inflow of large rivers, and the melting of ice add fresh water and dilute the salt, lowering salinity. Areas near river mouths and the equator therefore have lower salinity.
• Movement and mixing of water: Ocean currents and the free movement of water in the open sea mix and even out salinity, while enclosed and land-locked seas with little exchange develop extreme (high or low) salinity.

(c) Three ways oceans are important to man

• They are a major source of food (fish, shellfish and other sea foods) and of minerals such as common salt.
• They serve as cheap highways for transport and trade by ships between countries and continents.
• They influence climate (moderating temperatures and providing moisture for rainfall) and are a source of energy, petroleum and tourism.

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(a) Five ways transportation contributes to economic development

• Movement of goods and raw materials: It carries raw materials to factories and finished goods to markets, keeping industries running.
• Opening up of remote areas: Roads and railways make interior and rural areas accessible, allowing their resources to be exploited and developed.
• Promotion of trade and commerce: It links producers with consumers within the country and abroad, widening the market and encouraging both internal and international trade.
• Creation of employment: The building, operation and servicing of transport systems provide jobs and incomes for many people.
• Encouragement of agriculture and industry: It enables farmers to sell perishable produce quickly, attracts industries to accessible sites, and promotes tourism and the growth of towns.

(b) Five factors that affect transport development

• Relief: Rugged mountains, steep slopes and valleys make road and rail construction difficult and costly, while flat land is easy to develop.
• Climate: Heavy rainfall, floods, snow or fog damage routes and disrupt movement.
• Nature of the land / drainage: Swamps, marshes, deserts and large rivers hinder construction and require costly bridges and drainage.
• Availability of capital and technology: Transport projects are expensive; shortage of funds and technical skill slows their development.
• Level of economic activity and population: Densely populated and economically active areas attract more transport routes, while sparsely settled areas have few. (Government policy also matters.)

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(a) Outline map of Nigeria showing the forest belts, towns and Lake Chad

Key: Mangrove (salt-water swamp) forest: Port Harcourt; Freshwater swamp forest: Warri; Tropical rainforest (high forest): Benin City. Lake Chad is shown at the north-eastern boundary of Nigeria.

(b) Characteristics of the tropical rainforest (high forest)

1. It consists of very tall evergreen broad-leaved trees, commonly reaching about 60 m in height.
2. There is a great variety of tree species rather than pure stands. Important species include iroko, mahogany, obeche and walnut.
3. The vegetation has distinct layers, namely upper, middle and lower storeys. The closed canopy admits little sunlight to the forest floor, so undergrowth is sparse. Buttress roots, lianas, climbers and epiphytes are common.

(c) Importance of the forest belts to Nigeria

1. They provide timber and poles for building, furniture making, paper production and other industries.
2. They supply firewood and charcoal for domestic fuel, as well as useful products such as fruits, nuts, rubber and medicinal herbs.
3. They conserve wildlife and provide sites for tourism; timber exports also earn foreign exchange for Nigeria.

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Explanatory notes (any two)

(a) Rift valley

A rift valley is a long, narrow, steep-sided trough formed when a block of land sinks (subsides) between two roughly parallel faults, or when the land on either side is uplifted. It is produced by tensional (pulling apart) forces in the earth's crust. The sunken block is called a graben. Rift valleys often contain long, deep lakes. The best example is the East African (Great) Rift Valley, which runs from the Red Sea through Ethiopia and Kenya, containing lakes such as Lake Turkana and Lake Malawi.

Diagram: a cross-section showing a central down-thrown block (graben) bounded by two normal faults, with the flanks standing higher.

(b) Horst

A horst is an upstanding block of land bounded by two roughly parallel faults, formed when the middle block is uplifted or when the blocks on either side sink. It is the opposite of a graben and results from either tensional or compressional forces. It appears as a block or fault mountain with steep sides and a fairly flat top. Examples include the Ruwenzori and the Vosges and Black Forest highlands of Europe.

Diagram: a cross-section showing a central up-thrown block standing above two down-thrown blocks on either side.

(c) Volcanic mountain

A volcanic mountain is a mountain built up by the accumulation of lava, ash and other materials ejected through a vent from the interior of the earth during volcanic eruptions. As successive eruptions pile up material around the vent, a cone with a crater at the top is formed. Examples include Mount Cameroon, Kilimanjaro and Mount Fuji.

Diagram: a cone showing the central vent (pipe), a magma chamber below, layers of lava and ash, and a crater at the summit.