Why is one desert hot and a rainforest wet, and why are some mountains so high? Learn how location, climate and landforms connect, with map skills and worked examples.
Why is the Sahara hot and dry while the Amazon basin is hot and wet? Why are the Himalayas so high, and why do some rivers end in wide, fan-shaped deltas? Why do most people live in a few parts of the world? Geography answers questions like these by linking three big ideas: where things are (regions and maps), what the weather is usually like there (climate), and what the land looks like (landforms). This guide builds those three ideas step by step, with worked examples, so that you can read a map, a climate graph and a landscape with confidence.
Position on Earth is described with latitude and longitude, and maps use scales and symbols. Climate is the average weather over many years, shaped by latitude, altitude, distance from the sea, ocean currents and winds. Landforms are made by forces inside the Earth (plate movements, volcanoes) and outside it (rivers, ice, waves and wind). Together, climate and landforms influence where people live and how they use the land.
Geography is the study of the Earth's surface, its features, and the relationships between people and their environment. It has two main branches. Physical geography studies natural features and processes: climate, mountains, rivers, oceans and ecosystems. Human geography studies people: where they live, how they use land, and how they build towns, farms and trade routes. The two are closely linked, because the natural world shapes human life and human activity changes the natural world.
Earth's surface is about 71% water and 29% land. The land is divided by convention into seven continents, and the water is divided into five oceans, as shown in our article Continents and Oceans.
To describe any position on Earth, geographers draw an imaginary grid of lines on the globe.
| Latitude | Longitude | |
|---|---|---|
| Direction | Lines run east to west, measured north or south | Lines run from pole to pole, measured east or west |
| Starting line (0°) | The Equator | The Prime Meridian, through Greenwich in London |
| Range | 0° to 90° north and south | 0° to 180° east and west |
| Also called | Parallels | Meridians |
Some lines of latitude have special names: the Tropic of Cancer (about 23.5° N), the Tropic of Capricorn (about 23.5° S), the Arctic Circle (about 66.5° N) and the Antarctic Circle (about 66.5° S). The area between the two tropics is called the tropics. The Equator divides the Earth into the Northern and Southern Hemispheres, and the Prime Meridian and the 180° line divide it into the Eastern and Western Hemispheres.
Distance. One degree of latitude is about 111 km on the ground. Two places 10° of latitude apart on the same meridian are about 10 × 111 = 1,110 km apart.
Time. The Earth turns through 360° in 24 hours, so it turns 15° every hour (360 ÷ 24 = 15). Two places 45° of longitude apart differ in local time by 45 ÷ 15 = 3 hours, and the place further east is ahead.
A map is a flat picture of part of the Earth. To use it, you need four basic tools.
A map has the scale 1 : 50,000. Two villages are 4.5 cm apart on the map. What is the real distance?
4.5 cm × 50,000 = 225,000 cm. Convert: 225,000 cm ÷ 100 = 2,250 m, and 2,250 m ÷ 1,000 = 2.25 km.
Contour lines are lines on a map that join places of equal height above sea level. Where contour lines are close together, the ground is steep. Where they are far apart, the ground is gentle. Closed circles of contour lines show a hill or a peak.
A region is an area that shares a common feature that sets it apart from other areas. Geographers define regions in different ways:
| Type of region | Defined by | Example |
|---|---|---|
| Formal | A shared, measurable feature | A climate zone, or an area where one language is spoken |
| Functional | Links to a central point | The area served by one city's transport and shops |
| Perceptual | What people feel or believe about a place | "The Mediterranean" as a holiday region |
The seven continents are the largest land divisions. Their approximate shares of Earth's land are: Asia about 30%, Africa about 20%, North America about 16%, South America about 12%, Antarctica about 9%, Europe about 7% and Oceania about 6%. Asia is the largest and has more than half of the world's people. Each continent can be divided into smaller regions, and the names and boundaries of some regions differ between sources, so always check how a book or an examiner uses a term. For countries and their capitals, see Countries and Capitals.
Weather is the state of the atmosphere at a particular place and time: today's temperature, rain or wind. Climate is the usual pattern of weather in a place, calculated from measurements over a long period, usually at least 30 years. A useful saying is: "climate is what you expect, weather is what you get". Our article Weather and Climate: How the Atmosphere Works explains the atmosphere in more depth.
| Factor | How it works |
|---|---|
| Latitude | Near the Equator the Sun's rays strike more directly and heat a small area strongly, so it is warm. Near the poles the rays are spread over a larger area at a low angle, so it is cold |
| Altitude (height) | The air gets thinner and colder with height. The temperature falls by about 6.5°C for every 1,000 m |
| Distance from the sea | Water heats and cools slowly, so coasts have milder temperatures. Places far inland have hotter summers and colder winters |
| Ocean currents | Warm currents bring warmth to coasts and cold currents cool them |
| Prevailing winds | Winds from the sea bring moisture and rain, and winds from large land areas are usually dry |
| Relief (mountains) | Air forced to rise over mountains cools and drops its rain on the windward side |
A town at sea level has an average temperature of 30°C. What is the temperature at a mountain village 3,000 m higher, in the same area?
Fall = 6.5 × 3 = 19.5°C. New temperature = 30 − 19.5 = 10.5°C.
One striking effect of mountains is the rain shadow. Moist wind from the sea rises over the mountains, cools, and drops its water as rain or snow on the windward side. By the time the air crosses the top, it is dry, and as it sinks on the far side it warms and takes up moisture rather than giving it. The land beyond the mountains may therefore be a dry area or even a desert.
| Zone | Where and features | Typical vegetation |
|---|---|---|
| Tropical | Near the Equator: hot all year, with heavy rain in at least part of the year | Rainforest, and savanna grassland where there is a dry season |
| Dry (arid and semi-arid) | Often near 30° N and S, where sinking dry air prevents rain, and in rain shadows: very little rain, large day-night temperature range | Desert, scrub and sparse grass |
| Temperate | Mid-latitudes: mild with four seasons; some areas have dry summers (Mediterranean) and others have rain all year | Deciduous forest, evergreen woodland, grassland |
| Continental | Large land areas at mid and high latitudes: hot summers and very cold winters | Grassland, and cold-climate coniferous forest (taiga) |
| Polar | Near the poles and on high mountains: cold all year, with little precipitation | Tundra, and ice with almost no plants |
Plants and animals adapt to their climate, and large natural regions with similar climate and life are called biomes. Our article on Ecosystems and Biodiversity describes how living things fit into them. Note that Antarctica, though covered by ice, is technically the largest desert in the world, because a desert is defined by very low precipitation, not by heat. The Sahara is the largest hot desert.
A climate graph shows the average monthly temperature as a line and the average monthly rainfall as bars. Study the data below for an imaginary town, Town X.
| Month | Temp (°C) | Rain (mm) |
|---|---|---|
| January | 5 | 55 |
| February | 6 | 45 |
| March | 9 | 50 |
| April | 12 | 48 |
| May | 16 | 52 |
| June | 19 | 50 |
| July | 21 | 42 |
| August | 21 | 50 |
| September | 18 | 55 |
| October | 13 | 65 |
| November | 8 | 68 |
| December | 5 | 60 |
Temperature range = highest − lowest = 21 − 5 = 16°C.
Mean annual temperature = total ÷ 12 = 153 ÷ 12 = 12.75°C.
Total annual rainfall = 640 mm. The wettest month is November (68 mm) and the driest is July (42 mm).
Description: Town X has mild summers and cool winters, with rain in every month and no dry season. This pattern matches a temperate climate with year-round rain.
When you describe a climate in an exam, mention the overall pattern, the highest and lowest temperatures, the temperature range, the total rainfall and any seasonal pattern, using figures from the graph. Our article The Water Cycle and Earth's Water Systems explains where rain comes from.
A landform is a natural feature of the Earth's surface, such as a mountain, valley, plain or beach. Landforms are made by two kinds of forces. Internal forces act inside the Earth, such as the movement of tectonic plates and volcanoes, and they build up the land. External forces act on the surface, such as water, ice, wind and waves, and they wear down and reshape it. Three processes do the shaping: erosion (wearing away rock), transport (carrying the material away) and deposition (dropping it somewhere new).
The Earth's outer layer is broken into large pieces called tectonic plates, which move slowly, by a few centimetres a year. Where they meet, dramatic landforms appear. (See our article Earth's Structure: Layers, Plates and Earthquakes.)
| Landform | How it forms | Example |
|---|---|---|
| Fold mountains | Two plates collide and the rock between them is squeezed and folded upwards | The Himalayas, the Alps |
| Volcanoes | Molten rock (magma) reaches the surface and builds a cone-shaped mountain over many eruptions | Mount Fuji, and many peaks in the Andes |
| Rift valleys | Plates pull apart and a block of land sinks between two faults | The East African Rift |
| Block mountains | Blocks of rock are pushed up between faults | The Sierra Nevada |
| Plateaus | Large, high, flat areas, often lifted by internal forces | The Tibetan Plateau |
Earthquakes and volcanic eruptions happen mostly along plate boundaries. You can read about their effects in Natural Disasters: Earthquakes, Volcanoes and Hurricanes.
A river changes along its path from the source (where it begins) to the mouth (where it meets the sea or a lake). Geographers describe three stages, or courses.
| Course | Features | Main processes |
|---|---|---|
| Upper | Steep, narrow V-shaped valleys, rapids and waterfalls | Strong downward erosion; large rocks carried |
| Middle | Wider valley, gentle slope, bends called meanders | Erosion on the outside of bends, deposition on the inside |
| Lower | Wide, flat floodplain, ox-bow lakes, and a delta at the mouth | Mainly deposition of fine sediment |
Rivers erode in four main ways: hydraulic action (the force of water), abrasion (rocks scraping the bed and banks), attrition (rocks knocking against each other and becoming smaller and rounder) and solution (dissolving of some rocks). A meander can grow until a loop is cut off, and the abandoned loop becomes an ox-bow lake. At the mouth, when a slow river drops its sediment into the sea faster than waves and currents can remove it, a delta forms, such as the Nile Delta. The Grand Canyon shows what a powerful river can do: the Colorado River cut it over millions of years.
| Agent | Landforms | How they form |
|---|---|---|
| Glaciers (moving ice) | U-shaped valleys, corries, fjords | Ice scrapes and widens river valleys into a U shape; a fjord is a glacial valley later flooded by the sea |
| Waves | Cliffs, wave-cut platforms, beaches, spits | Waves erode cliff bases and carry material; where waves lose energy, they deposit sand and shingle |
| Wind | Sand dunes, desert pavements | Wind picks up and drops sand, mainly in dry areas where there is little plant cover |
Where do people live? Geographers find that most people settle where life is easiest: where there is fresh water, flat and fertile land, a mild climate, and resources or trade routes. Many of the earliest large civilisations grew beside great rivers, such as the Nile, the Tigris and Euphrates, the Indus and the Yellow River, because river floods left rich soil and water for crops. Today, more than half of the world's people live in towns and cities, and most of those cities are on coasts, rivers or other flat, accessible land.
Climate is not fixed. Earth's climate has changed many times in the past, but scientific measurements show that the global average temperature has risen by roughly 1.1°C or more since the late 1800s. Scientists explain that greenhouse gases, such as carbon dioxide and methane, trap heat in the atmosphere, a natural effect that keeps Earth warm enough for life. Human activities, especially burning fossil fuels, clearing forests and some farming practices, have increased the amount of these gases, which strengthens the effect.
The consequences include melting glaciers and ice sheets, rising sea levels, more frequent heatwaves, and changing rainfall patterns that can bring both droughts and floods. People respond in two main ways: mitigation (reducing the causes, for example by using cleaner energy and protecting forests) and adaptation (adjusting to the changes, for example building flood defences or growing drought-resistant crops). For reliable, current information, see the sources in Further Reading below.
| Misconception | Correct idea |
|---|---|
| Weather and climate are the same | Weather is short-term; climate is the long-term average |
| Deserts are always hot | A desert is a very dry area; Antarctica is a cold desert |
| Mountains are cold because they are closer to the Sun | They are cold because the air is thinner and holds less heat |
| The seasons happen because Earth is closer to the Sun | They happen because Earth's axis is tilted |
| The Equator is the hottest place everywhere | Many hot deserts lie near 30° N and S, and altitude can make the Equator cool |
| Maps show true shapes and sizes | Flat maps always distort some shapes or sizes |
| Rivers always flow in a straight line to the sea | They bend and form meanders, especially in the middle and lower courses |
| Longitude measures north and south | Latitude measures north and south; longitude measures east and west |
| Term | Meaning |
|---|---|
| Latitude / Longitude | Distance north or south of the Equator / east or west of the Prime Meridian, in degrees |
| Scale | The relationship between a distance on a map and the real distance |
| Contour line | A line on a map joining points of equal height |
| Region | An area that shares a feature that sets it apart from other areas |
| Climate | The usual weather of a place, averaged over many years |
| Rain shadow | A dry area on the sheltered side of a mountain range |
| Biome | A large natural region with a similar climate and living things |
| Landform | A natural feature of the Earth's surface |
| Erosion, transport, deposition | Wearing away, carrying away, and dropping of material |
| Delta | A landform made of sediment deposited where a river meets the sea |
| Greenhouse gas | A gas that traps heat in the atmosphere |
Geography is the science of connections. Latitude helps to explain temperature, mountains help to explain rainfall, rivers explain fertile plains and deltas, and all of them together help to explain where people settle and what they can grow. When you look at a map or a photograph of a landscape, ask three questions: where is this, what is the climate like, and how did the land get this shape? With practice, those three questions will let you read almost any part of the world, even one you have never seen.
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