WAEC SSCE - Geography - 2018

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The depletion of petroleum reserves is the factor that is likely to make petroleum drilling unimportant. Petroleum is a finite resource, meaning that once the available reserves have been extracted, there will be no more petroleum to extract. As petroleum is the primary resource extracted through drilling, the depletion of reserves will ultimately lead to a decrease in the importance of petroleum drilling. This could be due to a variety of reasons, including the high demand for petroleum products, declining reserves, or the development of alternative energy sources. While adequate capital, skilled labor, and good management are essential for the success of petroleum drilling, they are not sufficient to make it important if there are no reserves left to extract.

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The climatic data in the table above shows a consistent high temperature with two seasons - a wet season with high rainfall and a dry season with low rainfall. This type of climate is known as a tropical wet and dry climate, also known as a savanna climate. Gao (Mali) is a town located in the Sahelian zone, which experiences a hot desert climate with very little rainfall. The temperature and rainfall data in the table do not match this climate type, so Gao is not the town that experiences the climate represented in the table. Cairo (Egypt) is a town located in the desert, which experiences a hot desert climate with very low rainfall. The temperature in the table is consistent with a hot climate, but the rainfall data does not match the hot desert climate type. Therefore, Cairo is not the town that experiences the climate represented in the table. Warri (Nigeria) is a town located in the Niger Delta region, which experiences a tropical wet and dry climate, consistent with the data in the table. The high temperature and rainfall in the wet season in the table match the characteristics of a tropical wet and dry climate. Therefore, Warri is the town that experiences the climate represented in the table. London (England) is a town located in a temperate climate zone, which experiences mild temperatures and rainfall throughout the year. The high temperature and rainfall in the table do not match this climate type, so London is not the town that experiences the climate represented in the table. In summary, based on the temperature and rainfall data in the table, the town that experiences the type of climate represented is Warri, Nigeria.

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The feature that is associated with river capture is "Wind gap". River capture is a geomorphological process that occurs when a river erodes its channel and captures the drainage of another river or stream. This usually happens when the two rivers flow in close proximity, and one of them has a more rapid rate of erosion than the other. Over time, the faster-eroding river may break through the divide between the two rivers, diverting the water flow from the other river into its own channel. As a result of river capture, a wind gap may be formed in the area where the diverted river previously flowed. A wind gap is a narrow, steep-sided valley or gap in a ridge or mountain range, which was previously occupied by a river or stream. The term "wind gap" comes from the fact that the gap is often occupied by strong winds that blow through the valley or gap. Therefore, "Wind gap" is the feature associated with river capture.

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The core of the Earth is composed primarily of Iron and Nickel, with small amounts of other elements such as Silicon, Sulfur, and Carbon. These elements are found in the Earth's core because they are dense and able to withstand the immense pressure and high temperatures found at the center of the planet. The combination of Iron and Nickel creates an alloy that is even denser and stronger, making it the ideal material for the Earth's core.

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Carbonaceous sedimentary rocks are made from vegetative matter. Carbonaceous sedimentary rocks are a type of rock that contains high levels of carbon, such as coal, shale, and limestone. These rocks are formed from the accumulation and compaction of organic material, which is primarily composed of vegetative matter, such as dead plants and trees. Over time, as layers of dead vegetation accumulate in swamps and wetlands, they are buried under sediment and rock. As more layers accumulate, the weight of the overlying material compresses and heats the layers beneath, causing the organic material to undergo a process of chemical and physical change called diagenesis. This process results in the formation of coal, shale, and other carbonaceous sedimentary rocks. In contrast, sedimentary rocks that are made from the remains of dead animals, such as limestone or chalk, are not considered to be carbonaceous. These rocks form from the accumulation and compaction of shells, bones, and other calcium-rich material produced by marine organisms.

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Natural increase in population means excess of births over deaths. This means that the number of births in a population is greater than the number of deaths in a given period of time, usually a year. Natural increase is an important factor in determining population growth. When there are more births than deaths, the population increases naturally without the need for migration. This can have significant implications for a country's economy and social structure, as a growing population can place pressure on resources and infrastructure. It is important to note that natural increase is just one factor that affects population growth. Migration, both immigration and emigration, can also significantly impact population size. However, when natural increase is positive, it means that the population is growing through the natural process of births and deaths.

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The intensive farming techniques are those which involve a high level of inputs such as labor, capital, and technology to produce high yields per unit of land. Out of the given options, land rotation, crop rotation, mixed farming are all examples of intensive farming techniques. Land rotation involves moving crops from one area of land to another in a planned way to maintain soil fertility, while crop rotation involves the systematic planting of different crops in the same field to prevent soil depletion and control pests. Mixed farming is the practice of combining crop cultivation with the rearing of animals for food and other products. Market gardening, on the other hand, is not an intensive farming technique. It refers to the small-scale production of fruits, vegetables, and flowers for sale in local markets. This practice typically involves lower levels of inputs and is often done on small plots of land close to urban areas. In summary, while land rotation, crop rotation, and mixed farming are all examples of intensive farming techniques, market gardening is not an intensive farming technique.

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The correct term for a community of plants and animals living in harmony within the same physical environment is an ecosystem. An ecosystem refers to a biological community of living organisms (plants, animals, and microbes) in conjunction with their non-living environment (air, water, and soil) and the interactions between them. All the living organisms in an ecosystem depend on each other and their physical environment to survive. For instance, plants provide food and oxygen for animals, while animals help in pollination and seed dispersal for plants. This interconnectedness creates a balance, leading to the coexistence of various species in a harmonious way.

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The annual range of temperature for the station is 2°C. This means that the difference between the highest and lowest temperatures recorded in a year is 2°C. In this case, the highest temperature recorded is 28°C (in August) and the lowest temperature recorded is 26°C (in January, February, March, April, May, October, and November).

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A feature commonly found in the youthful stage of a river is a meander. A meander is a bend or curve in a river that forms as the river erodes the outer bank and deposit sediment on the inner bank. Meanders are characteristic of a youthful river because the river has a lot of energy and is actively eroding and depositing sediment. As the river ages and slows down, the meanders become more pronounced and can eventually lead to the formation of ox-bow lakes. Ox-bow lakes are formed when a meander becomes so pronounced that the river cuts through the narrow strip of land, creating a new channel. The old channel becomes isolated and forms a lake. Levees are mounds of sediment that form along the banks of a river and are used to prevent flooding. Interlocking spurs are ridges of rock or sediment that form along a river and help to control the river's flow.

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In Koppen's classification of climates, "Cs" refers to the "Mediterranean" climate. This climate is characterized by mild, wet winters and hot, dry summers. It is typically found in coastal regions with prevailing westerly winds, such as the Mediterranean Basin, California, and parts of South Africa and Australia. The mild temperatures and ample rainfall in the winter support a diverse range of vegetation, while the dry summers prevent forests from becoming too dense.

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The statement best describes administrative towns. Administrative towns are centers of government and are typically the location of government offices, parliament buildings, and other administrative institutions. They are often the capital city of a country or region and are responsible for the management and implementation of policies and laws. Examples of administrative towns include Washington D.C. in the United States, London in the United Kingdom, and Brasília in Brazil. In summary, administrative towns are places where governments have their headquarters, and they play a significant role in the management of the country or region.

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To find the mean temperature from July to December, we need to add up the temperatures for those months and then divide by the number of months (which is 6 in this case, as we are considering July to December). The sum of temperatures for July to December is: 27 + 28 + 28 + 28 + 27 + 27 = 165 To get the mean temperature, we divide this sum by 6: 165 / 6 = 27.5°C Therefore, the mean temperature from July to December is 27.5°C.

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In the Northern Hemisphere, the summer solstice is experienced on June 21st. The summer solstice marks the longest day of the year and the official start of summer in the Northern Hemisphere. This occurs because the Earth's axis is tilted towards the sun, allowing the sun's rays to hit the Northern Hemisphere more directly than at any other time of the year. Conversely, during the winter solstice, which occurs on December 22nd, the Earth's axis is tilted away from the sun, making it the shortest day of the year in the Northern Hemisphere. It's important to note that these dates may vary slightly from year to year, but generally, the summer solstice occurs around June 21st in the Northern Hemisphere.

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Autotrophs, heterotrophs, and decomposers are associated with ecosystems. Autotrophs are organisms that can produce their own food using energy from the sun, such as plants, algae, and some bacteria. Heterotrophs are organisms that cannot produce their own food and must consume other organisms for energy, such as animals and some bacteria. Decomposers are organisms that break down dead organic matter into simpler substances, such as fungi and bacteria. These three types of organisms play important roles in ecosystems. Autotrophs are at the base of the food chain, producing energy that is then consumed by heterotrophs. Decomposers break down dead organic matter, returning nutrients to the soil and allowing them to be used again by autotrophs. Together, these organisms help to maintain the balance of energy and nutrients within an ecosystem. Vegetation, climate, and geology are all important components of an ecosystem, but they are not directly associated with autotrophs, heterotrophs, and decomposers.

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The type of rain mostly experienced within the tropics is convectional rain. This type of rain is formed by convection, which is the transfer of heat and moisture from the ground to the atmosphere. In the tropics, where the air is warm and moist, the heat causes water vapor to rise and condense into clouds. When the clouds become heavy with moisture, they release the water as rain. Convectional rain is common in the tropics due to the warm and moist conditions, making it the most frequently experienced type of rain in this region.

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Relief rainfall is mostly associated with highlands. This means that the type of rainfall known as relief rainfall is most commonly found in areas with high elevations, such as mountains or plateaus. This type of rainfall occurs when moist air is lifted as it moves over high terrain, causing the air to cool and condense into clouds that produce rain. In this way, relief rainfall is a direct result of the physical features of the landscape, and is most commonly found in areas of high elevation.

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The pair of rocks that is not correctly shown is shale → graphite. Shale is a sedimentary rock composed of mud or clay particles that have compacted over time. Graphite, on the other hand, is a mineral that is formed from the metamorphism of carbon-rich rocks such as limestone or shale. While shale can undergo metamorphism to become slate, it does not naturally transform into graphite. Graphite is formed under very specific geological conditions that involve the high temperature and pressure necessary for the carbon in the rock to re-crystallize into the mineral graphite. Therefore, the pair of rocks that is not correctly shown is shale → graphite.

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The characteristic of Wadis that is not correct is "They hold permanent streams". Wadis are usually dry riverbeds or channels that contain water only during the rainy season. They are a common feature in arid and semi-arid regions, especially in the Middle East and North Africa. Wadis are usually characterized by steep craggy walls, which are formed by the erosion of the surrounding rocks and soil over a long period of time. They are often located in areas with low rainfall and are fed by intermittent streams that only flow during the rainy season. Therefore, "They hold permanent streams" is not a characteristic of Wadis.

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The most predominant occupation of most of the population of West African countries is farming. This is because agriculture is the main source of income and employment for many people in the region. The fertile soil and favorable climate conditions in West Africa make it an ideal place for agricultural activities. Farming in West Africa is predominantly done through subsistence farming, which involves growing crops mainly for personal consumption rather than for commercial purposes. However, there is also commercial farming which involves the production of cash crops such as cocoa, coffee, rubber, and palm oil for exportation. Overall, farming is a crucial aspect of West African culture and economy, providing food and income for millions of people in the region.

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Stalactites and stalagmites are associated with limestone rock. Limestone is a sedimentary rock that is composed mainly of calcium carbonate. Stalactites and stalagmites form in caves, where water containing dissolved calcium carbonate drips from the cave ceiling and then deposits the calcium carbonate, creating a growing column that eventually forms a stalactite. The water then drips onto the floor and deposits more calcium carbonate, creating a stalagmite. Over time, these formations can grow to become very large and impressive. Limestone is the most common rock type for the formation of stalactites and stalagmites because it is easily dissolved by water and is abundant in many parts of the world.

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The envelope of gases surrounding the Earth's crust is called the atmosphere. The atmosphere is a layer of gases that surrounds the Earth and is held in place by gravity. It is composed of various gases, including nitrogen (78%), oxygen (21%), and other trace gases such as carbon dioxide and helium. The atmosphere plays a crucial role in regulating the Earth's temperature, protecting it from harmful radiation, and providing the air we breathe. It is divided into five layers based on temperature, with the troposphere being the layer closest to the Earth's surface and the exosphere being the outermost layer. The hydrosphere refers to all the water on Earth, including oceans, lakes, rivers, and groundwater. The lithosphere refers to the solid outer layer of the Earth, which includes the crust and uppermost part of the mantle. The barysphere refers to the Earth's core, which is composed of primarily iron and nickel.

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The characteristic of subsistence farming is that it is a type of agriculture in which the produce is mainly for home consumption, meaning that it is not primarily intended for sale or trade. Subsistence farming is typically carried out on a small scale, and it relies heavily on manual labor and simple farming tools. Since it is often done by small farmers who have limited resources, it is not capital-intensive. Therefore, the option that is not a characteristic of subsistence farming is "It is capital intensive."

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The nearest planet to the sun is Mercury. Mercury is the smallest planet in our solar system and is located closest to the sun. It is named after the Roman messenger god, Mercury, and completes one orbit around the sun in just 88 Earth days. Despite being closest to the sun, Mercury is not the hottest planet in our solar system. That distinction belongs to Venus, which has a thick atmosphere that traps heat and creates a greenhouse effect, making it the hottest planet.

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(a) Four modes of transportation

• Road transport (vehicles on roads).
• Rail transport (trains on railways).
• Water transport (ships and boats on seas, rivers and lakes).
• Air transport (aeroplanes and helicopters).
• Pipeline transport (for oil, gas and water).

(b) Four constraints to inland water navigation

• Rapids, waterfalls and cataracts that interrupt navigation.
• Silting and sandbanks that make rivers shallow.
• Seasonal variation in water level: many rivers dry up or become too shallow in the dry season.
• Floating vegetation (e.g. water hyacinth) and other obstacles blocking channels.
• Sharp bends and winding courses that slow large vessels.
• Rocks and submerged obstacles.

(c) Four ways the constraints can be solved

• Dredging the rivers to remove silt and deepen the channel.
• Building dams and locks to regulate water level and by-pass rapids and waterfalls.
• Removing rocks, weeds and obstacles, and clearing floating vegetation such as water hyacinth.
• Straightening and canalising winding sections and cutting canals to link rivers.
• Providing navigation aids (buoys, lights) and regular maintenance of the waterway.

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(a) Characteristic features

(i) Conurbation

• It is formed when several once-separate towns and cities grow and merge into one continuous built-up urban area.
• It has a very large total population and covers a large area with continuous built-up land, e.g. Greater London or the West Midlands.

(ii) Megalopolis

• It is a very large urban region formed by the coalescing of several conurbations and cities into a continuous belt of urban development.
• It has an extremely large population spread over a vast area, with heavy interlinking of transport, e.g. the Boston-to-Washington belt (Boswash) in the USA.

(b) Six functions which settlements perform (with examples)

• Administrative function: centres of government, e.g. Abuja (Nigeria) and Washington (USA) as capitals.
• Commercial/trade function: centres of buying and selling, e.g. Lagos, Kano, Onitsha as trading and market towns.
• Industrial/manufacturing function: centres of factories and processing, e.g. Ikeja/Lagos and Pittsburgh.
• Educational function: centres of learning, e.g. Ibadan and Nsukka as university towns.
• Religious function: centres of worship and pilgrimage, e.g. Mecca, Jerusalem and Ile-Ife.
• Port/route (transport) function: ports and route-focus towns, e.g. Port Harcourt, Apapa and Warri.
• Mining function: towns based on mineral extraction, e.g. Enugu (coal) and Jos (tin).
• Resort/tourist and residential functions, e.g. resort towns and dormitory suburbs.

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(a) Five sources of water pollution

• Industrial waste and effluents discharged into rivers and lakes.
• Domestic sewage and human waste.
• Agricultural chemicals (fertilisers, pesticides and herbicides) washed into water bodies.
• Oil spillage from tankers, pipelines and oil-drilling operations.
• Dumping of refuse and solid waste into water bodies.
• Mining waste and toxic tailings.
• Thermal (hot water) discharge from industries.

(b) Five measures to control water pollution

• Treatment of industrial and domestic waste before it is discharged into rivers, seas or lakes.
• Enforcement of anti-pollution laws and penalties against offenders.
• Proper waste disposal: provide sewage systems and refuse dumps away from water bodies, and discourage dumping of refuse into rivers.
• Controlled use of agricultural chemicals (fertilisers and pesticides) and use of organic manure.
• Prompt clean-up and prevention of oil spillage and regular maintenance of pipelines and tankers.
• Public enlightenment and education on the dangers of water pollution.
• Recycling of waste and building of buffer/vegetation strips along water bodies.

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(a) Three characteristics of manufacturing industries in Tropical Africa

• They are mostly light industries that process agricultural and mineral raw materials (e.g. food processing, textiles, tanning) rather than heavy engineering.
• They are small in scale, with low capital investment and limited output serving mainly local markets.
• They are concentrated in a few large towns, ports and mining areas, leaving rural areas largely without industry.
• They depend heavily on imported machinery, spare parts and technical expertise.
• They are largely labour-intensive rather than highly mechanised.

(b) Three ways manufacturing industries contribute to economic development

• Employment: they provide jobs, reducing unemployment and raising incomes.
• Provision of goods: they supply manufactured goods locally, reducing dependence on imports and saving foreign exchange (import substitution).
• Foreign exchange earnings: export of processed goods brings in foreign currency.
• Government revenue through taxes and duties.
• Development of infrastructure (roads, power, water) and growth of towns around industrial centres.
• They add value to local raw materials and stimulate agriculture and mining.

(c) Four problems facing industrial development in Tropical Africa

• Shortage of capital for investment in machinery and plant.
• Inadequate power supply and unreliable electricity.
• Shortage of skilled labour and management and technical know-how.
• Small home markets due to low incomes and poor purchasing power.
• Poor transport and communication networks.
• Competition from cheaper, better-quality imported goods.
• Political instability and unfavourable government policies.

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(a) Four ocean routes used in world trade

• The North Atlantic route: links Western Europe with North America; the busiest ocean route.
• The Suez Canal (Mediterranean-Red Sea) route: links Europe with East Africa, the Middle East, India and the Far East.
• The Panama Canal route: links the Atlantic and Pacific Oceans, joining eastern North America and Europe with the west coast of America and the Pacific.
• The Cape of Good Hope route: links Europe with West and South Africa and the East via the southern tip of Africa.
• The North Pacific route: links North America (west coast) with East Asia (Japan, China).
• The South Atlantic route: links Europe and North America with South America and West Africa.

(b) Four ways water transportation has contributed to economic development

• It carries bulky and heavy goods (oil, timber, minerals, grain) cheaply over long distances.
• It promotes international trade by linking producing and consuming countries across the world.
• It has led to the growth of port towns and cities and their industries.
• It provides employment for sailors, dockworkers, ship-builders and traders.
• It earns foreign exchange and government revenue through freight charges and port dues.
• It opens up interior regions where rivers and lakes are navigable.

(c) Four ways of improving transportation on inland waterways

• Dredging of rivers and channels to remove silt and deepen them for larger vessels.
• Removal of obstacles such as rocks, sandbanks and floating weeds (e.g. water hyacinth).
• Construction of dams and locks to regulate water level and bypass rapids and waterfalls.
• Canalisation and straightening of winding rivers, and linking rivers by canals.
• Provision of modern port facilities, jetties, warehouses and navigation aids (buoys, lights).
• Regular maintenance and use of modern, powered vessels.

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(a) Two advantages of industrialisation in Nigeria

• It creates employment, reducing unemployment and raising incomes.
• It promotes import substitution and earns foreign exchange, so the country depends less on imported goods.
• It adds value to local raw materials and provides government revenue through taxes.

(b) Four problems that retard industrialisation in Nigeria

• Inadequate and unreliable power supply, forcing firms to run costly generators.
• Shortage of capital for investment and high interest rates on loans.
• Shortage of skilled labour and technical manpower.
• Poor transport and infrastructure, raising production costs.
• Competition from cheaper imported goods and dumping.
• Over-dependence on imported machinery and raw materials.
• Political instability and unfavourable government policies.

(c) Four ways the problems could be solved

• Improve and stabilise power supply by investing in and diversifying electricity generation.
• Provide capital through cheap loans, incentives and encouragement of local and foreign investment.
• Train skilled manpower through technical and vocational education.
• Develop transport and infrastructure (roads, rail, ports).
• Protect local industries from unfair imports through tariffs and patronage of made-in-Nigeria goods.
• Develop local raw materials to reduce dependence on imports, and maintain political stability with consistent policies.

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(a) Sketch map of Nigeria showing selected manufacturing centres

An outline of Nigeria is drawn below. One important area is located and named for each of the three products required:

• Cement: Sagamu / Ewekoro (Ogun State, south-west), which lies on the limestone belt used for cement production.
• Cocoa products: Ibadan (Oyo State, south-west), a processing centre in the cocoa-growing belt.
• Flour: Kano (Kano State, north), a major flour-milling centre serving the northern grain area.

(b) Three benefits of large-scale manufacturing industries in Nigeria

1. Provision of employment: they absorb a large labour force, thereby reducing unemployment and raising incomes of workers.
2. Revenue generation: they yield revenue to government through company taxes, duties and levies, which finance public services.
3. Foreign-exchange earning and conservation: by exporting finished goods they earn foreign exchange, and by producing locally (import substitution) they conserve the foreign exchange that would have been spent on imports.

Other benefits include the development of social amenities and infrastructure, stimulation of other sectors of the economy (agriculture, mining, transport), growth of towns, and diversification of the economy.

(c) Three advantages of large-scale over small-scale manufacturing industries

1. Lower unit cost of production: large-scale firms enjoy economies of scale, so the cost of producing each unit is lower than in small-scale firms.
2. Greater access to capital: large firms can readily procure funds and credit from financial institutions and attract investment, which small firms cannot easily obtain.
3. Ability to engage in research and use advanced technology: large-scale industries can afford modern machinery and fund research, giving higher productivity and better-quality output.

Additional advantages include more efficient operation and advertisement, higher skill acquisition and manpower development, provision of welfare facilities, and a greater ability to absorb business risks.

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(a) Sketch map of Nigeria

The sketch map below shows the outline of Nigeria with the required features named: the River Niger entering from the north-west and the River Benue entering from the north-east, meeting at their confluence at Lokoja before flowing south to the Niger Delta; the Kainji Dam on the River Niger in the north-west; and Abuja, the Federal Capital, near the centre of the country.

(b) Three factors which favour the development of hydro-electric power (HEP) projects in Nigeria

1. Presence of rapids, waterfalls and a steep gradient. Along the River Niger at sites such as Kainji and Jebba, and along tributaries near Shiroro on the Kaduna River, the land drops sharply. This provides a good \(head\) of water so that fast-falling water can spin the turbines with force.
2. Large and permanent volume of water in the rivers, fed by abundant rainfall. The Niger, the Benue and their tributaries carry a high, reliable volume of water all year round because the country receives heavy seasonal rainfall. A steady supply of water is needed to keep the turbines running continuously.
3. Availability of strong bedrock at suitable dam sites. Narrow valleys with firm, impermeable rock foundations (as at Kainji) allow engineers to build strong dams that can hold back a large reservoir safely without water leaking through the base.

(Other favourable factors include the high demand and market for electricity from a large population and growing industries, and the availability of capital and skilled labour for construction.)

(c) Three economic benefits of hydro-electric power projects

1. Generation of cheap electricity for industrial use, which promotes industrialisation and the growth of new towns.
2. Supply of electricity for domestic use, improving the standard of living in homes and towns.
3. Provision of water for irrigation from the reservoir, boosting agricultural production and food supply. (Further benefits include revenue generation, flood control, employment of workers, fishing and tourism at the reservoir, and improved inland navigation.)

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(a) Definition of conurbation

A conurbation is a large, continuous built-up urban area formed when several once-separate towns and cities grow outward and merge into one another, so that their boundaries can no longer be clearly distinguished.

(b) One example of a conurbation in two different countries

• United Kingdom: Greater London (or the West Midlands conurbation around Birmingham).
• United States of America: the New York metropolitan conurbation (or Greater Los Angeles).

(Other acceptable examples: Greater Tokyo in Japan; the Ruhr conurbation in Germany.)

(c) Four problems associated with conurbations

• Overcrowding and shortage of housing, leading to slums and high rents.
• Traffic congestion on roads and pressure on transport.
• Environmental pollution (air, water and noise) and waste-disposal problems.
• Pressure on social amenities such as water, electricity, schools and hospitals.
• High crime rates and social vices.
• Unemployment and pressure on job opportunities.

(d) Four solutions to the problems

• Build more housing estates and satellite/new towns to reduce overcrowding.
• Improve and expand the transport system (mass transit, ring roads, flyovers) to ease congestion.
• Provide proper waste-disposal and pollution-control measures and enforce environmental laws.
• Expand and improve social amenities (water, power, schools, hospitals).
• Decentralise industries and administration to other regions to reduce migration into the conurbation.
• Improve security and create employment opportunities.

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

• Size of population: some are small towns, others are large cities or conurbations.
• Function: settlements differ in their main activity, e.g. administrative (capital), industrial, commercial, port, mining, religious or educational towns.
• Site and situation: some are coastal, others inland, on hills, along rivers or at route junctions.
• Morphology (shape/pattern): some are planned with regular street patterns, others grow irregularly; shapes may be linear, nucleated or radial.
• Age and level of development: old traditional towns differ from modern planned cities in infrastructure and layout.

(b) Three factors contributing to high population density in Japan

• Highly developed industry and commerce: Japan is one of the world's leading manufacturing nations, attracting people to industrial cities such as Tokyo, Osaka and Nagoya.
• Limited lowland (plains): because Japan is mountainous, people crowd onto the narrow coastal plains, raising density there.
• Intensive, productive agriculture (especially rice) on the fertile lowlands supports a large population.
• Good fishing grounds and a highly developed fishing industry support many people.
• Well-developed transport and trade and a temperate climate favourable to settlement.

(c) Three problems resulting from high population density in Japan

• Overcrowding and shortage of land for housing, leading to very high land and housing costs.
• Pressure on social amenities such as transport, water and health facilities, causing congestion.
• Environmental pollution (air, water and noise) from dense industry and traffic.
• Reclamation of land from the sea and hills at high cost to create more space.
• Traffic congestion in the large cities.

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(a) Definition of shifting cultivation

Shifting cultivation is a form of farming in which a piece of land (usually cleared by cutting and burning the bush) is cultivated for a few years until its fertility declines, then abandoned; the farmer moves to clear and cultivate a fresh piece of land, often relocating his settlement as well.

(b) The practice of shifting cultivation in Nigeria

(i) Three characteristics

• Land is cleared by the slash-and-burn method (cutting the vegetation and burning it, the ash acting as fertiliser).
• A plot is cultivated for a few years, then abandoned to fallow when fertility falls, and a new plot is opened.
• Simple tools (hoe and cutlass) and family labour are used; farms are small and mixed cropping is common.

(ii) Two benefits

• Burning and long fallow allow the soil to regain its fertility naturally without chemical fertilisers.
• It requires little capital and simple tools, so it is cheap and suitable for poor farmers.

(iii) Four disadvantages

• It requires large areas of land and is wasteful where land is scarce.
• Output is low, producing little surplus for sale or industry.
• Burning destroys soil organisms and exposes the land to erosion and loss of nutrients.
• Constant movement makes it hard to provide permanent infrastructure and to mechanise.
• Deforestation and destruction of vegetation result from repeated clearing and burning.

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(a) Sketch map of Nigeria showing one mining area for each mineral

The map below is an outline of Nigeria on which one producing area is marked and named for each of the three minerals: coal at Enugu (south-east), crude oil in the Niger Delta / Port Harcourt (south-south) and limestone at Ewekoro-Sagamu (south-west).

(b) Process of mining coal in Nigeria

Coal in Nigeria (notably at Enugu) is worked mainly by the underground (adit / drift) method, and where seams lie near the surface by the open-cast method.

Underground (adit) method:

1. The overlying soil and rock (overburden) covering the seam are first removed or a tunnel is driven in.
2. A horizontal or gently sloping tunnel (adit) is cut into the hillside to reach the coal seam.
3. Timber props made from strong tree trunks are built to support the roof of the mine and prevent collapse.
4. Fresh air is pumped into the mine by machines to ventilate it, and water is drained out.
5. Explosives may be used to loosen and aid the excavation of the coal seam.
6. Pick-axes, drills and cutting machines are used to break the coal from the seam.
7. Shovels are used to load the broken coal onto tubs or a conveyor belt.
8. The coal is conveyed out of the mine to the surface, then sorted and graded.
9. It is finally transported by rail or truck to the point of consumption or to the ports for export.

Open-cast method (where the seam is shallow): the overburden is stripped off; explosives are used to break the exposed seam; pick-axes and shovels loosen and load the coal; it is conveyed by rail or truck to the processing plant and then to the point of use or export.

(c) Four problems affecting the mining industry in Nigeria

1. Shortage of capital and investment for exploration, machinery and expansion.
2. Inadequate skilled labour and technical expertise, together with the high cost and scarcity of spare parts.
3. Poor transport, infrastructure and erratic power supply to the mining areas.
4. Insecurity, illegal mining and price fluctuation of minerals on the world market, which discourage steady production.

Detalles de la respuesta

None

Detalles de la respuesta

(a) Three characteristics of subsistence agriculture in Nigeria

• Farming is on a small scale, on tiny scattered plots, to feed the farmer and his family with little or no surplus for sale.
• Simple tools such as the hoe and cutlass are used; there is little or no mechanisation.
• It relies on family labour rather than hired workers.
• Mixed cropping (growing several crops on the same plot) is common, and bush fallowing is used to restore soil fertility.
• Output is low and depends heavily on the weather; few or no chemical fertilisers or improved seeds are used.

(b) Four advantages of subsistence agriculture

• It provides food directly for the farmer and his household, ensuring food security at family level.
• It requires little capital, land and simple tools, so it is affordable to poor rural people.
• Mixed cropping reduces the risk of total crop failure and gives a varied diet.
• It provides employment and occupation for rural families.
• Bush fallowing and mixed cropping help conserve soil fertility and reduce erosion.
• Any small surplus can be sold to earn some income.

(c) Three disadvantages of subsistence agriculture

• Output is low, producing little or no surplus for sale or for feeding the growing urban population.
• It cannot support agro-based industries because raw material supply is small and irregular.
• Use of crude tools and small plots keeps productivity and farmers' incomes low.
• It is difficult to mechanise because of small, scattered fragmented holdings.
• Heavy dependence on the weather makes yields unreliable.