Scale is the ratio between a distance on a map and the corresponding actual distance on the ground. It can be expressed in three forms:

• Statement scale — "1 cm represents 1 km"
• Representative Fraction (RF) — 1:100,000 (means 1 unit on map = 100,000 of the same units on the ground)
• Linear/Graphic scale — a drawn line divided into measured units

Bearing is the direction from one point to another, measured clockwise from North (0°–360°). Always give as three digits: 045°, 270°, etc.

A contour line joins points of equal height above sea level. The contour interval is the vertical difference between adjacent contour lines.

A cross-profile (cross-section) is a side-view diagram drawn between two points on a map. Steps: (1) place paper along the line, mark where contours cross; (2) plot each mark at its height on graph paper; (3) join the dots to reveal the relief.

A Geographic Information System (GIS) is a computer-based system for capturing, storing, analysing, and displaying geographical data. It links location data (where?) with attribute data (what?).

Sources of GIS data: land surveying, remote sensing, map digitising, map scanning, field investigation, tabular data (census, administrative records).

Uses of GIS: defence and security, agriculture (crop mapping), urban development and planning, transport route planning, census and population mapping, natural disaster management.

Remote sensing is the collection of information about the earth's surface without direct physical contact — using satellites, aircraft cameras, and radar. Data is used to produce imagery for land use, vegetation mapping, environmental monitoring, and disaster assessment.

Vulcanicity refers to all processes by which molten material (magma) reaches the earth's surface or forms underground features.

• Intrusive features (magma cools underground): Batholith, laccolith, dyke, sill, boss
• Extrusive features (lava erupts at surface): Composite/stratified volcano, shield volcano, lava plateau, caldera

Earthquakes are sudden vibrations of the earth's crust caused by movement along faults or volcanic activity. Key terms:

• Focus/Hypocentre — the point underground where the earthquake originates
• Epicentre — the point on the earth's surface directly above the focus
• Seismograph — instrument that records earthquake waves; Richter scale measures magnitude

Denudation is the breaking down and removal of surface material.

Ocean currents are masses of ocean water that flow continuously in fixed paths across the oceans.

Causes of ocean currents: prevailing winds, rotation of the earth (Coriolis effect), differences in water density (temperature and salinity), shape of ocean basins.

Salinity is the amount of dissolved salts in seawater, expressed in parts per thousand (‰). Average ocean salinity is about 35‰. It is higher in enclosed seas and in tropical regions due to high evaporation; lower in polar regions and near river mouths.

Weather is the atmospheric condition of a place at a specific time. Climate is the average weather condition of a place over a long period (at least 30 years).

Elements of weather and climate: temperature, rainfall/precipitation, humidity, sunshine, cloud cover, air pressure, wind speed and direction.

Factors controlling climate: latitude (distance from equator), altitude (temperature falls ~6.5°C per 1,000m rise), ocean currents (warm/cold), prevailing winds, continentality (distance from sea), aspect (direction a slope faces).

Soil is the uppermost layer of the earth's crust, composed of mineral particles, organic matter (humus), water, air, and living organisms.

Factors of soil formation: parent rock (determines mineral content), climate (temperature and rainfall drive weathering), living organisms (plants and animals add organic matter), topography (slope affects drainage), and time.

O — Organic layer: leaf litter, plant remains
A — Topsoil: rich in humus, dark colour, most root activity
B — Subsoil: less organic matter, accumulated minerals
C — Weathered parent rock fragments
R — Solid bedrock (parent material)

Soil erosion — removal of topsoil by wind, water, or human activity. Types: sheet erosion, rill erosion, gully erosion, splash erosion.

Causes: deforestation, overgrazing, poor farming practices, steep slopes, heavy rainfall.

Conservation measures: afforestation/reforestation, contour ploughing, strip cropping, terracing, cover crops, construction of check dams.

Population distribution describes where people live on the earth's surface. Population density = total population ÷ total land area (persons per km²).

Areas of high population density: NE USA, Western Europe, South/East Asia (India, China, Japan), Nile Delta. Areas of low density: deserts, polar regions, dense rainforests, high mountains.

Birth rate = number of live births per 1,000 population per year. Death rate = number of deaths per 1,000 per year. Natural increase rate = birth rate − death rate.

Problems of rapid population growth (developing countries): food insecurity, pressure on healthcare and education, unemployment, housing shortage, urban overcrowding, environmental degradation.

Problems of slow/declining population (developed countries): ageing population, reduced workforce, high dependency ratio, pressure on pension/healthcare systems.

Factors influencing settlement location: water supply, defence (hilltops, river bends), fertile soil, shelter from wind, route junctions, historical and political factors.

Urban hierarchy: hamlet → village → town → city → conurbation → megalopolis. As settlements grow they provide higher-order functions (banking, hospitals, universities).

Migration is the movement of people from one place to another with the intention of settling.

Factors of industrial location: raw materials (near source reduces cost), power supply, labour (skilled and abundant), transport and communication, capital, market (large population), government policy, water supply.

Modes of transport:

• Road — most flexible, door-to-door; expensive for long distances and bulk goods
• Rail — efficient for bulk goods over long distances; high fixed costs
• Water (inland and sea) — cheapest for bulk goods internationally; slow
• Air — fastest; expensive; best for high-value, perishable or urgent goods
• Pipeline — ideal for oil, gas and water; high initial cost but low running cost

World trade — exchange of goods and services between countries. Reasons for trade: unequal distribution of natural resources, differences in climate, level of technological development, specialisation (comparative advantage).

Problems of world trade for developing countries: unfavourable terms of trade, dependence on few primary exports (price fluctuations), trade protectionism by developed countries, poor transport and infrastructure.

Tourism is the temporary movement of people to destinations outside their normal place of work and residence for leisure, recreation, education, business or health purposes.

Reasons for tourism: leisure and recreation, education, health (spa/medical tourism), business, religious pilgrimage, adventure, visiting friends and relatives.

Tourist centres in Nigeria: Olumo Rock (Abeokuta), Yankari Game Reserve (Bauchi), Osun-Osogbo Sacred Grove, Obudu Cattle Ranch (Cross River), Zuma Rock (Abuja), Lagos Bar Beach, National Museum Lagos, Kano City walls.

Nigeria is located in West Africa between latitudes 4°N and 14°N and longitudes 3°E and 15°E. It has an area of approximately 923,768 km², making it the largest country in West Africa by population.

It is bounded to the north by Niger Republic and Chad, to the west by Benin Republic, to the east by Cameroon, and to the south by the Gulf of Guinea (Atlantic Ocean). It is divided into 36 states and the FCT (Abuja), grouped into six geopolitical zones: North-West, North-East, North-Central, South-West, South-East, South-South.

Major rivers: Niger (longest — enters from NW, flows south to Gulf of Guinea), Benue (major tributary of Niger), Cross River, Sokoto, Kaduna, Anambra, Osun, Ogun.

Problems of agriculture in Nigeria: poor access to credit/finance, inadequate storage facilities, low mechanisation (hoe and cutlass farming), land tenure system, poor rural roads, climate variability, pests and diseases, rural-urban migration of young people.

Problems of industrialisation in Nigeria: inadequate power supply, poor infrastructure, foreign exchange scarcity, dependence on imported raw materials, low technology, political instability, high interest rates.

Major seaports: Lagos (Apapa, Tin Can Island), Port Harcourt (Onne), Calabar. Major airports: Lagos (Murtala Muhammed), Abuja (Nnamdi Azikiwe), Kano (Mallam Aminu Kano), Port Harcourt.

The Economic Community of West African States (ECOWAS) was established on 28 May 1975 in Lagos, Nigeria, by the Treaty of Lagos. It currently has 15 member states:

Headquarters: Abuja, Nigeria. Official languages: English, French, Portuguese.

Rural development aims to improve the quality of life in rural areas through better roads, electricity, water supply, schools and healthcare.

Environmental conservation measures in Nigeria:

• Forest reserves and national parks (Yankari, Cross River National Park, Kainji)
• NESREA (National Environmental Standards and Regulations Enforcement Agency) — regulates pollution
• Environmental Impact Assessment (EIA) required before major projects
• Afforestation and reforestation programs in the Sahel
• Great Green Wall project — belt of trees across the Sahel to stop desertification

You've now covered all major WAEC and JAMB Geography topics. Take the 60-question timed CBT practice to see your score and get a personalised breakdown by section.