WAEC SSCE - Geography - 1992

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The large diurnal ranges of temperature in tropical deserts occur mainly because of the absence of cloud cover. In tropical deserts, the sky is usually clear, allowing sunlight to penetrate directly to the ground and heat it up during the day. At night, the clear sky also allows the heat to radiate back into space, leading to a rapid drop in temperature. This temperature difference between day and night can be significant, often reaching 20-30°C or more, which is what we refer to as a large diurnal range of temperature. The other options given are not the primary causes of large diurnal temperature ranges in tropical deserts. While scarcity of water and absence of highlands may contribute to temperature variations, they are not the main drivers of diurnal temperature changes. Prevalence of strong winds may cause variations in temperature, but it is not the primary cause of large diurnal ranges. Similarly, the absence of tradition is not a factor that affects temperature in tropical deserts.

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The greatest threat to the survival of ECOWAS is the inability to implement agreed policies. ECOWAS, or the Economic Community of West African States, is a regional organization that aims to promote economic integration and cooperation among its member states. However, the success of this organization relies heavily on its ability to implement policies and agreements that benefit its member states. If policies are not implemented, then the goals of the organization cannot be achieved, and member states may become frustrated and disillusioned with the organization. This could lead to a lack of trust and cooperation among member states and ultimately threaten the survival of ECOWAS. The other options listed, such as different languages spoken and different monetary systems in use, may present challenges to achieving economic integration, but they are not the greatest threat to the survival of ECOWAS.

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An eclipse of the moon occurs when the earth comes between the moon and the sun. During a lunar eclipse, the Earth blocks the sun's light from directly reaching the moon. Instead, the Earth's shadow falls on the moon, causing it to appear reddish-brown or orange in color. This happens because some of the sunlight passing through the Earth's atmosphere is scattered and refracted, so that longer-wavelength light (like red and orange) is more likely to reach the moon.

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The major effect of drought in Nigeria is population migration. Drought is a natural disaster that results from prolonged periods of low rainfall, which can cause crops to fail and water sources to dry up. In Nigeria, many people depend on agriculture for their livelihoods, so when there is a drought, it can lead to food shortages and economic hardship. As a result, many people are forced to migrate to other areas in search of food and water. This can lead to overcrowding in cities and other areas, as well as social and economic problems. In addition, drought can also have other effects, such as increased temperatures and dust storms, which can exacerbate health problems and damage infrastructure.

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The option that does not contribute to the high cost of building and maintaining roads in West Africa is the infertility of some lands. Infertility means the land is unable to produce crops or plants, but this does not necessarily affect the construction and maintenance of roads. On the other hand, the swampy coastal areas, numerous rivers to be crossed, mountainous nature of some regions, and torrential downpour are all factors that contribute to the high cost of building and maintaining roads in West Africa. For instance, building roads in swampy coastal areas or regions with numerous rivers would require expensive bridge constructions or land reclamation, which would add to the overall cost. Similarly, constructing roads in mountainous regions would require more resources and effort due to the difficult terrain, while torrential downpour can easily damage roads, leading to higher maintenance costs.

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Venus is the planet that has no natural satellite. Unlike other planets such as Earth and Mars, which have one or two moons, and Jupiter and Saturn, which have dozens of moons, Venus does not have any known natural satellites. The reason for this is still not well understood, but one theory suggests that Venus may have had a moon in the past, but it collided with another object or was ejected from orbit due to gravitational interactions with the sun. However, this theory is still a subject of ongoing research and debate among scientists.

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The most predominant action in the first horizon of a soil profile is eluviation. Eluviation is the process by which water percolates through the soil and carries dissolved minerals and organic matter from the upper layers to the lower layers. This creates a zone of accumulation of nutrients, minerals, and organic matter in the lower layers, which is called the illuvial horizon. The first horizon of the soil profile is also known as the A horizon, which is the topsoil layer that contains the most organic matter and is the most fertile. Therefore, the process of eluviation plays a significant role in determining the fertility of the soil in the first horizon.

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Wheat is a cereal grain and is typically grown in regions with temperate climates. In Nigeria, wheat is grown mainly in the northern states where the weather is more suitable for its cultivation. Based on this information, the state that is less likely to grow wheat is Rivers, which is located in the southern part of Nigeria and has a tropical climate. Therefore, the answer to the question is Rivers.

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The term used to describe a port that is auxiliary to another port further inland which cannot be reached by very large ships is "a river port". A river port is a port that is located on a river and is used for the loading and unloading of cargo from ships. River ports are usually smaller than seaports and are often used for transporting goods to and from inland areas that are not accessible by large ocean-going vessels. River ports are important for trade and commerce in many parts of the world, as they provide a means of transport for goods and commodities that cannot be easily transported over land.

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Winds in anticyclones differ from winds in cyclones mainly because they blow outwards. Anticyclones are high-pressure systems characterized by sinking air. The sinking air warms and dries, resulting in the formation of clear skies and dry weather conditions. Because of the high-pressure area, winds tend to flow outward and away from the center, resulting in a clockwise direction in the Northern Hemisphere and an anticlockwise direction in the Southern Hemisphere. In contrast, cyclones are low-pressure systems characterized by rising air. The rising air cools and condenses, resulting in cloud formation and often leading to precipitation. As a result, winds tend to flow inwards and towards the center of the system in a counterclockwise direction in the Northern Hemisphere and a clockwise direction in the Southern Hemisphere.

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Plants that manufacture food from simple inorganic substances are called autotrophs. Autotrophs are organisms that can produce their own food using energy from the sun or from chemical reactions. In the case of plants, they use a process called photosynthesis to convert carbon dioxide and water into glucose (a type of sugar) and oxygen. During photosynthesis, plants capture the energy from the sun and use it to power chemical reactions that convert carbon dioxide and water into glucose. This process takes place in specialized structures called chloroplasts, which are found in the leaves of the plant. Chlorophyll, a pigment found in the chloroplasts, is responsible for capturing the energy from the sun and using it to power photosynthesis. Autotrophs are also known as producers because they are the base of the food chain in most ecosystems. Other organisms, such as animals and some microbes, cannot produce their own food and rely on autotrophs (or other heterotrophs) for their energy needs. Therefore, the correct option is autotrophs.

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Most imports to Nigeria are consumer goods. This includes a wide range of products such as electronics, household appliances, clothing, and food items that are intended for personal or household use. Nigeria is a developing country and while it has a large agricultural and industrial sector, it still relies heavily on imports to meet its domestic demand for consumer goods. While Nigeria does import raw materials, primary products, pharmaceuticals, and perishables, these items do not make up the bulk of its imports. Raw materials and primary products are typically imported for use in Nigeria's manufacturing and industrial sectors. Pharmaceuticals are imported to meet the country's healthcare needs. Perishables, such as fruits and vegetables, are also imported to supplement domestic production, but they do not make up the majority of Nigeria's imports.

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Out of the resources listed, only one resource is renewable, which is hydro-electricity. Petroleum, peat, coal, and natural gas are all non-renewable resources, which means that they cannot be replenished once they are used up. These resources take millions of years to form, and the rate at which they are consumed is much faster than the rate at which they are produced. On the other hand, hydro-electricity is generated using the kinetic energy of flowing water, which is a renewable source of energy as long as the water source remains available. The water that drives the turbines is replenished by natural processes such as precipitation and the water cycle, making it a sustainable source of energy.

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The correct arrangement representing an increasing size of settlements is: Hamlet, village, town, conurbation. A hamlet is a small settlement that usually has only a few houses, while a village is larger than a hamlet but smaller than a town. A town is larger than a village, and a conurbation is the largest settlement, comprising of several towns and cities that have grown and merged together. Therefore, as we move from a hamlet to a village, then to a town, and finally to a conurbation, the size and population of the settlement increase. Hence, the above-mentioned arrangement represents an increasing size of settlements.

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The form of subsistence farming that is not commonly practiced in West Africa is plantation agriculture. Plantation agriculture is a form of commercial farming where large tracts of land are cultivated with a single crop, usually for export purposes. This is not a typical form of subsistence farming because it requires significant financial investment, expertise, and technology to set up and maintain. On the other hand, mixed farming, rotational bush fallowing, permanent cultivation, and pastoral nomadism are common forms of subsistence farming in West Africa. Mixed farming involves cultivating different crops and raising animals on the same piece of land, while rotational bush fallowing involves moving from one plot of land to another in order to allow the soil to regenerate. Permanent cultivation involves farming a plot of land continuously for a long period of time without letting it lie fallow, and pastoral nomadism involves moving herds of animals from place to place in search of grazing land.

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A high population density means that there is a large number of people in a particular area, usually measured as the number of persons per unit area. This means that the population in that area is dense, or crowded. Population density is an important factor in understanding the level of pressure that the population is placing on the available natural resources, the level of urbanization, the level of pollution, and the overall quality of life of the population. Therefore, option B - "persons per unit area" - is the correct answer.

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Port Harcourt is a typical example of a "terminal town". A terminal town is a city or town that serves as a transportation hub or terminal for a region, connecting it to other areas through various modes of transportation such as roads, railways, and ports. In the case of Port Harcourt, it is a major port city in Nigeria, located on the Bonny River and the Gulf of Guinea. It serves as a hub for the transportation of goods and people in the region, connecting the surrounding areas to other parts of the country and the world through its port, airport, and road network. Port Harcourt is also home to several major oil companies and industries, which rely on its transportation infrastructure to export their products to other parts of the world. Therefore, as a terminal town, Port Harcourt plays a crucial role in the economic development of the region and the country as a whole.

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A catchment area is the area of land where all the rainwater or snowmelt that falls within that area flows to a common point, usually a river, lake or ocean. This water is collected by the land and runs off into waterways, where it can be used for drinking, irrigation, or other purposes. Essentially, it's the area of land through which a river flows and collects water from.

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The standard railway gauge is 143cm. The railway gauge is the distance between the inner sides of the two parallel rails that make up a railway track. The standard gauge of 143cm was adopted as an international standard because it provides a good balance between stability and flexibility for trains. A wider gauge provides greater stability but makes the track more expensive to build, while a narrower gauge is cheaper but less stable, which can cause derailments. The 143cm gauge is used in many countries around the world, including the United States, Canada, Australia, and most of Europe, among others.

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Hydro-electricity is a renewable resource. This is because it is generated from the energy of moving water, which is constantly replenished by rainfall and the water cycle. The water flows through a turbine to generate electricity, and the process can be repeated indefinitely as long as there is water flowing through the system. On the other hand, petroleum, coal, natural gas, and peat are all non-renewable resources. They are formed over millions of years from the remains of dead plants and animals, and once they are extracted and burned, they cannot be replaced. As a result, they will eventually run out and are not sustainable in the long term.

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Ways in which poor transportation can limit the economic development of a country (for example Nigeria):

Transport is the means by which people, raw materials and goods are moved from place to place. Where it is poor (few, badly maintained roads, limited rail, few navigable rivers, high costs), development is held back in the following ways:

• Restricted movement of goods and raw materials: factories cannot obtain raw materials cheaply or distribute their finished goods easily, so industries are discouraged and remain small.
• Discouragement of agriculture: farmers in remote areas cannot move their produce to market before it spoils, so they produce little for sale; farm produce rots and prices are unstable.
• High cost of goods and services: where transport is difficult, the cost of moving goods is high, which raises the prices of goods and lowers people's real income.
• Isolation of regions and uneven development: areas without good transport are cut off, so investment, trade and social services concentrate in the few accessible places, leaving other regions backward.
• Hindrance to trade (internal and external): poor links to ports, markets and neighbouring countries reduce the volume of trade and foreign exchange earnings.
• Discouragement of investment and industry: investors avoid areas that are hard to reach, so new industries and businesses are not established there.
• Limited exploitation of resources: minerals, forests and other resources in inaccessible areas cannot be developed because they cannot be moved out economically.
• Slow movement of labour and reduced tourism: workers cannot easily reach places of work, and tourists are put off by difficult travel, so both the labour market and the tourist industry suffer.

Thus poor transportation slows down agriculture, industry, trade, and the even spread of development, keeping the country's economy weak.

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(a) Meaning of environmental resource:

An environmental resource is any material or feature of the natural environment that is useful and of value to man in satisfying his needs. It includes both natural (physical) resources such as water, soil, minerals, forests, air, wildlife and sunlight, and it becomes a resource only when man has the knowledge and ability to make use of it. Environmental resources may be renewable (water, forests, wind) or non-renewable (minerals, crude oil).

(b) Importance of water as an environmental resource (with examples):

• Domestic use: water is needed for drinking, cooking, washing and other household activities.
• Agriculture: water is used for irrigation of crops and for watering livestock, for example irrigation in the Sokoto and Chad basins.
• Industry: factories use water for processing, cooling and cleaning, for example in breweries and textile mills.
• Generation of electricity: fast-flowing or dammed rivers produce hydro-electric power, for example the Kainji Dam on the Niger.
• Transport and fishing: rivers, lakes and seas serve as cheap waterways for boats and support fishing, for example on the River Niger and Lake Chad.
• Tourism and recreation: waterfalls, beaches and lakes attract tourists and provide recreation.

(c) Three sources of water:

• Rainfall collected directly or in reservoirs.
• Surface water from rivers, streams, lakes and ponds.
• Underground water obtained from wells, boreholes and springs.

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(a) Relationship between rainfall and agricultural practices

(i) Tropical continental region of Nigeria (Guinea and Sudan savanna, the north)

• Rainfall is moderate to low (about 500 to 1000 mm) and highly seasonal, with a long dry season, so farming is limited mainly to the short wet season.
• The single, short rainy season permits only one cropping season per year, and drought-tolerant crops such as guinea corn (sorghum), millet, groundnut and cotton are grown.
• Where the dry season is severe, farmers depend on irrigation (for example rice and vegetables) to supplement rainfall.
• The grassland cover supports extensive livestock rearing (cattle, sheep and goats).

(ii) Sub-equatorial region of Nigeria (the south)

• Rainfall is heavy (over 2000 mm) and well distributed over most of the year, giving a long growing season.
• The abundant, double-maxima rainfall allows two cropping seasons and the cultivation of moisture-loving crops such as oil palm, cocoa, rubber, yam, cassava and plantain.
• Rainfall reliability makes rain-fed farming the norm, with little need for irrigation.
• The very heavy rainfall can cause leaching and soil erosion, so tree/perennial crops that protect the soil are favoured.

(b) Five ways agriculture contributes to the economy of Nigeria

• Provision of food: It supplies food for the rapidly growing population.
• Employment: It employs a large proportion of the working population, especially in rural areas.
• Raw materials for industry: It supplies materials such as cotton, oil palm and rubber to agro-based industries.
• Foreign exchange: Export crops such as cocoa and rubber earn foreign currency.
• Government revenue: Taxes and duties on agricultural produce provide revenue to government.
• Source of income: It provides income and improved living standards for farmers.

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Two vegetation types chosen: (a) Equatorial and (b) Tropical continental (savanna).

(a) Equatorial (tropical rain-forest) vegetation

(i) Vegetation characteristics:

• Tall, dense, evergreen forest arranged in three storeys (emergents, canopy, under-storey), with trees reaching 40 metres or more.
• Broad-leaved hardwoods (mahogany, iroko, ebony) with buttress roots; leaves have drip-tips.
• Great variety of species mixed together, with abundant lianas (climbers), epiphytes and a dark, bare forest floor.

(ii) How climate has influenced it: the constant high temperatures (about \(27^\circ C\)) and heavy, year-round rainfall (over \(2000\ mm\)) with no dry season allow continuous, rapid plant growth, so the forest stays green all year. Competition for light makes the trees grow tall in layers, the heavy rain produces drip-tips and buttress roots, and the warm damp conditions support a huge variety of species.

(b) Tropical continental (savanna) vegetation

(i) Vegetation characteristics:

• Tall, coarse grasses (often 1 to 3 metres) with scattered, short deciduous trees, giving a parkland appearance.
• Trees are drought- and fire-resistant, with thick bark, umbrella-shaped crowns, small leaves and deep roots (acacia, baobab, shea).
• Grass turns green in the wet season and dries brown in the dry season; trees become fewer and shorter towards the desert margin.

(ii) How climate has influenced it: the savanna has a marked wet and dry season. During the long dry season plants must survive drought, so trees shed their leaves, develop thick fire-resistant bark and long roots, and store water (baobab), while the grasses dry up and survive as roots and seeds. The seasonal, moderate rainfall (about \(750\ mm\) to \(1000\ mm\)) is enough for grass and scattered trees but not for continuous forest.

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(a)(i) Two local craft industries and one important town for each

• Leather working - Kano.
• Cloth weaving / dyeing (adire, aso-oke) - Iseyin/Abeokuta (also Akwete weaving at Akwete).

(Others: pottery - Ilorin; wood carving - Awka; brass/bronze - Benin; mat making - Ikot Ekpene.)

(a)(ii) Two manufacturing industries and one important town for each

• Cement manufacturing - Ewekoro (also Sokoto, Obajana).
• Textile manufacturing - Kaduna (also Lagos, Aba).

(Others: vehicle assembly - Lagos/Kaduna; petroleum refining - Port Harcourt/Warri; brewing - Lagos.)

(b) Four problems facing local craft industries (with examples)

• Competition from cheaper factory-made goods: Imported and factory textiles undersell hand-woven aso-oke and adire, reducing demand for the local product.
• Shortage of capital and credit: Craftsmen such as Ilorin potters and Awka carvers lack funds to buy better tools and expand.
• Use of crude, outdated tools: Kano leather workers and local dyers rely on simple hand tools, so output is slow and quality varies.
• Poor marketing and finance/scarcity of raw materials: Weak organisation, poor roads and rising cost of raw materials (hides, cotton, clay) limit sales and profit; young people also prefer white-collar jobs, so skills are being lost.

(c) Three ways the problems are being solved

• Provision of loans and grants: Government and banks give soft loans and support through agencies (e.g. SMEDAN, Bank of Industry) to fund craftsmen.
• Training and cooperative organisation: Craft centres and cooperatives train workers, improve tools and skills, and market the goods jointly.
• Promotion and protection of local crafts: Trade fairs, exhibitions and encouragement of patronage (including some restriction on cheap imports) expand the market for local products.

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Comparison of irrigation agriculture in the Nile Basin and the Niger Basin

In summary, irrigation is more essential, more extensive and more highly developed in the Nile Basin because of its desert setting, whereas in the Niger Basin irrigation is more localised and needed chiefly in the drier northern and inland-delta sections, since the southern parts receive enough rain.

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(a) (i) One sea route linking Nigeria with Europe

The Cape Route (round the Cape of Good Hope) is one such route. A more direct alternative is the route through the Gulf of Guinea, across the Atlantic Ocean to the English Channel and the ports of north-western Europe. (Either the Cape Route or the trans-Atlantic Gulf of Guinea route is acceptable.)

(ii) Two European countries that trade with Nigeria using the route

• United Kingdom
• Netherlands (others acceptable: France, Germany, Spain, Italy)

(b) Four products carried along the route

• From Nigeria: crude petroleum, cocoa, and rubber.
• To Nigeria: manufactured goods such as machinery and vehicles.

(c) Five ways international trade is important to Nigeria

• Foreign exchange earnings: The export of crude oil, cocoa and other goods earns foreign currency used to finance development.
• Government revenue: Import and export duties provide substantial revenue to the government.
• Supply of goods not produced locally: Trade makes available machinery, vehicles and manufactured goods that Nigeria does not produce in sufficient quantity.
• Employment: Trade-related activities in ports, shipping, banking and haulage provide jobs for many people.
• Promotion of international relations: Trade fosters friendly and cooperative relations between Nigeria and her trading partners.
• Market for surplus: It provides an outlet for Nigeria's surplus agricultural and mineral products.

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(a) On an outline map of Africa, locate, name and label the following mining areas, towns and ports of export.

Use different symbols or colours for copper, gold and iron ore on the map. Mark the mining areas, dot and name the towns, and mark the ports on the coast. Add a suitable key.

(b) Four ways in which copper is important to Zambia are:

(i) Copper provides foreign exchange

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(a) Outline map of West Africa: January conditions

• (i) ITCZ in January: draw the Inter-Tropical Convergence Zone lying to the south, roughly along or just off the Guinea coast (about 5°N over the ocean).
• (ii) Low pressure belt in January: mark it over the equatorial south, close to the ITCZ near the coast, where the sun is nearly overhead.
• (iii) High pressure belt in January: mark it over the Sahara in the north (the sub-tropical high over North Africa).
• (iv) Tropical Continental air mass (cT): show it as the dry, dusty Harmattan blowing from the north-east (Sahara) toward the south-west, with an arrow.
• (v) Guinea current: a warm current flowing eastward along the Guinea coast; (vi) Canary current: a cool current flowing south-westward along the north-west coast (Mauritania/Senegal).

(b) Relationship between pressure belts and rainfall distribution

• The rain-bearing belt follows the low pressure (ITCZ): Rainfall is heaviest where the ITCZ and the low pressure lie, because moist maritime Tropical (mT) south-west monsoon air converges and rises there, cooling to give rain.
• High pressure means dry weather: Under the sub-tropical high, air is subsiding (sinking) and the dry continental Tropical (cT) Harmattan blows out; this area (the north/Sahara) is dry, so rainfall decreases northward.
• The belts migrate with the overhead sun: In July the low pressure and ITCZ move far north, bringing the rainy season to most of West Africa; in January they move south, so only the coast gets some rain while the interior is dry. Hence rainfall is highest and longest near the coast and decreases toward the interior, following the seasonal shift of the pressure belts.

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(a) Outline map of Nigeria: transport features

• (i) Two international airports: Murtala Muhammed (Lagos) in the south-west and Nnamdi Azikiwe (Abuja) in the centre. (Others: Port Harcourt, Kano.)
• (ii) Two domestic airports: Ibadan in the south-west and Ilorin in the middle belt. (Others: Maiduguri, Yola, Benin.)
• (iii) Two seaports: Lagos (Apapa/Tin Can) in the south-west and Port Harcourt in the south-south. (Others: Warri, Calabar.)
• (iv) Two river ports: Onitsha on the River Niger and Lokoja at the Niger-Benue confluence. (Others: Baro, Yola on the Benue.)

Mark each with a small symbol (aircraft for airports, anchor for ports) in its correct position and label it.

(b) Four problems facing river transportation in Nigeria

• Seasonal variation in water level: Rivers are shallow in the dry season, so large boats cannot navigate for part of the year.
• Silting and sand bars: Deposition of silt and sand blocks channels and reduces depth, making navigation difficult.
• Rapids, waterfalls and rocky obstacles: Sudden falls and rocks interrupt the courses of many rivers, so goods must be off-loaded and moved by land.
• Floating vegetation and few modern facilities: Water hyacinth and weeds clog channels, while poor port facilities, dredging and jetties limit efficiency.

(c) How the problems are being solved

• Dredging: Rivers such as the Lower Niger are dredged to deepen channels and remove silt and sand bars for year-round use.
• Construction of dams: Dams (e.g. Kainji) regulate the flow so that a steady depth of water is maintained downstream.
• Clearing of vegetation and obstacles: Water hyacinth and rocks are removed and channels are marked to guide craft.
• Provision of modern port facilities: Building and equipping river ports (Onitsha, Lokoja, Baro) with jetties and cargo-handling equipment improves the service.

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(a) Difference between deflation and abrasion:

Deflation is the lifting and blowing away of loose, dry, fine material (dust, sand and silt) from the desert surface by the wind, so that the surface is lowered. Abrasion (corrasion) is the wearing away of rock surfaces by the wind using its load of sand grains as tools, rather like a natural sand-blasting; here the wind actively cuts and grinds solid rock. In short, deflation removes already-loose material, while abrasion erodes solid rock by rubbing sand against it.

(b) One landform produced by each process, with examples:

• Landform of deflation - a deflation hollow (blowout): where the wind repeatedly scoops away the loose sand, a shallow, saucer-shaped depression is formed. If the hollow is deepened until it reaches the water table, an oasis may develop. The Qattara Depression in Egypt is a large example.
• Landform of abrasion - a rock pedestal (mushroom rock, or zeugen/yardang): because the sand load is concentrated near the ground, the base of an upstanding rock is undercut faster than its top, leaving a mushroom-shaped rock with a narrow stem and broad cap, as seen in the Sahara.

(c) Two reasons why wind erosion is more active in arid than in humid regions:

• Scanty vegetation cover: deserts have little or no plant cover to bind the soil or shield the surface, so the wind can pick up and move material freely; in humid regions dense vegetation protects and holds the soil.
• Dry, loose surface material: the ground in arid areas is dry, so the fine particles are loose and easily lifted; in humid regions moisture binds the particles together and makes them heavy, so the wind cannot move them (strong steady winds in deserts also aid erosion).

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(a)(i) The Equinoxes:

An equinox occurs twice a year, on about 21 March (spring/vernal equinox) and 23 September (autumn equinox). At these times the sun is directly overhead at the Equator (the sun's vertical rays fall on \(0^\circ\) latitude). Because the circle of illumination passes through both poles, day and night are equal in length (12 hours each) all over the world. The word equinox means "equal night". Neither the North nor the South Pole is tilted towards the sun.

(a)(ii) Great circles:

A great circle is any circle drawn on the globe whose plane passes through the centre of the Earth, dividing the globe into two equal halves (hemispheres). It is the largest circle that can be drawn on the Earth's surface. The Equator is a great circle, and every pair of opposite meridians of longitude together forms a great circle. The parallels of latitude other than the Equator are small circles, because their planes do not pass through the centre of the Earth. The shortest distance between any two points on the globe lies along the arc of a great circle, which is why aircraft and ships follow great-circle routes.

(b) Why twilight lasts longer at the Arctic Circle than at the Equator:

Twilight is the period of half-light before sunrise and after sunset, caused by the atmosphere scattering the sun's rays while the sun is still below the horizon. Its length depends on the angle at which the sun sinks below the horizon. At the Equator the sun's daily path is almost vertical (perpendicular) to the horizon, so the sun drops quickly and steeply below the horizon, passing through the twilight zone in a short time; twilight is therefore brief. Near the Arctic Circle the sun moves in a path that is greatly slanted (oblique) to the horizon; it sinks very gradually and travels a long, shallow path just below the horizon, so its rays continue to light the sky for a much longer period. Hence twilight lasts far longer in high latitudes than at the Equator.

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(a) Outline map of Nigeria: relief and drainage features

• (i) Jos Plateau - central Nigeria; Idanre Hills - south-west (near Akure).
• (ii) River Ogun - flows south-west into the Lagos lagoon; River Cross - south-east, into the Atlantic near Calabar; River Hadejia - north-east, draining toward the Lake Chad basin.
• (iii) Lake Chad - far north-east corner; Lake Kainji (artificial) - west-central, on the River Niger.
• (iv) Niger Delta - fan of creeks and swamps where the Niger reaches the sea in the south-south.

Show rivers as lines with arrows toward their mouths, lakes as shaded patches, and highlands by shading; add a key.

(b)(i) Four physical features of the Niger Delta

• Low, flat and swampy land lying near sea level.
• Network of distributaries and creeks as the Niger splits before entering the sea.
• Mangrove and freshwater swamp forest with muddy, waterlogged soils.
• Sand bars, beach ridges and lagoons along the seaward edge, deposited by the river and the sea.

(b)(ii) Four physical features of the North Central Plateau (Jos Plateau)

• High, upland surface rising above the surrounding plains (around 1200-1800 m).
• Cool climate because of the altitude, cooler than the lowlands around it.
• Volcanic hills, cones and older granite rocks giving a rugged surface.
• Source of many rivers (a water divide) with steep edges/escarpments and tin-bearing rocks.

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(a) Four functions of towns, with a specific example of each:

• Administrative (capital) function: the town is a seat of government, for example Abuja.
• Commercial/trading function: the town is a centre of trade and business, for example Onitsha (or Lagos).
• Industrial (manufacturing) function: the town is a centre of manufacturing, for example Kano (textiles) or Warri (petroleum).
• Educational function: the town is a centre of learning, for example Ibadan or Nsukka (university towns). (Others: mining town - Enugu; religious town - Mecca; port town - Port Harcourt.)

(b) Four ways the initial function of a town can contribute to its growth:

• Attraction of population: the original function (say administration or industry) draws workers and their families, so the population increases.
• Provision of employment and services: the function creates jobs, which in turn attract shops, schools, hospitals and other services, enlarging the town.
• Development of infrastructure: to serve the function, roads, electricity, water and communication are provided, encouraging further settlement and investment.
• Attraction of other functions: the initial function attracts related activities (a capital attracts commerce, banks and industry), so the town grows and diversifies (multiplier effect).

(c) Three ways rural settlements depend on urban settlements:

• Market for produce: villages sell their farm produce and raw materials in the town's markets.
• Source of manufactured goods and services: villagers obtain manufactured goods, and specialised services such as hospitals, banks, secondary schools and administration from the town.
• Employment and income: villagers travel to the town to work and earn wages, some of which they bring back to develop the rural area (also higher-order services like courts and universities).

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None

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(a) Reasons for the relatively low level of industrial development in tropical Africa

• Shortage of capital: Most tropical African countries are poor with low per capita incomes and weak savings, so there is insufficient investment capital to establish and expand heavy industries.
• Inadequate power and energy supply: Electricity generation is irregular and insufficient, and many rural areas are not connected to the national grid, which discourages the siting of factories.
• Low level of technology and few skilled workers: There is a shortage of engineers, technicians and trained managers, and the region depends heavily on imported machinery and expertise.
• Small and low-income domestic market: Widespread poverty means low purchasing power, so demand for manufactured goods is small and cannot support large-scale industry.
• Poor transport and infrastructure: Bad roads, limited railways and inadequate port facilities raise the cost of moving raw materials and finished goods.
• Political instability and unfavourable policies: Frequent changes of government, insecurity and inconsistent economic policies scare away both local and foreign investors.
• Concentration on primary production: Colonial and post-colonial economies were geared toward exporting unprocessed raw materials rather than manufacturing them locally.
• Competition from imported goods: Cheaper and better-quality manufactured goods from industrialised countries out-compete local products.

(b) Five ways the industrial sector has contributed to economic development of the region

• Employment: Industries provide jobs to many people, thereby reducing unemployment and raising incomes.
• Revenue and foreign exchange: Taxes on industries and the export of manufactured goods earn government revenue and foreign currency.
• Provision of goods and reduced imports: Local manufacture of consumer goods reduces dependence on imports and saves foreign exchange.
• Development of infrastructure: The establishment of industries stimulates the building of roads, power supply, water and communication facilities.
• Growth of towns and other sectors: Industries encourage urbanisation and support agriculture (through processing) and mining (through demand for raw materials).

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(a) Sketch map of Nigeria showing population density

On the sketch map below, two areas of low population density and two areas of high population density are located, together with one important town in each area.

(b) Advantages

(i) Three advantages of low population density (taking the Minna / Middle Belt area)

1. Absence of environmental pollution: with few people, industries and vehicles, the air, water and land remain clean and healthy.
2. Availability of comfortable accommodation: land and housing are cheap and spacious, so residents enjoy comfortable, uncongested homes.
3. Absence of traffic congestion: the low number of people and vehicles means free-flowing roads and easy, stress-free movement.

(ii) Three advantages of high population density (taking the Lagos / South-West area)

1. Availability of employment: the large concentration of people supplies abundant labour and creates many job opportunities in industries and services.
2. Presence of heavy commercial activities: the large market of consumers stimulates trade, banking and vigorous buying and selling.
3. Presence of social amenities: the demand of the dense population attracts good roads, electricity, water, schools and hospitals.