A3.1 Landforms of the world
Earth's surface follows patterns: landforms built and worn by tectonic forces, weathering, erosion, and glaciation; river systems and drainage basins moving water to lakes and oceans; climate regions shaped by latitude, currents, winds, and elevation; and vegetation belts from tundra to rainforest. Natural processes and human activities keep changing all of them.
Example
Name the landform: high like a range, flat like a plain; the Andes and Himalayas; the Prairies.
- A plateau — high like a range, flat like a plain.
- Mountains that sit along the boundaries where tectonic plates meet.
- Plains — wide, level land with deep soil.
A3.2 Processes that shape landforms
Example
Name the process behind a river canyon and the Canadian Shield's scoured rock.
- Canyon: erosion by moving water — not deposition, glaciation or tectonics.
- Shield: massive sheets of moving ice scouring the surface in the last ice age.
Example
Name the process behind a strip mine's terraces, and tell weathering from erosion.
- Strip mine: a human activity that reshapes the land in years instead of ages. Weathering breaks rock where it stands; erosion carries it away.
A3.3 Topographic maps and cross-sections
Example
Read the figure: what does a contour line join, and what do crowded lines mean?
- A contour joins points that share the same elevation above sea level.
- Crowded contours mean a steep slope where the height changes quickly; spread-out ones mean gentle ground.
Example
Read the figure: what shape does the line from A to B cross?
- From A to B the labels read 100, 200, 300, then 300, 200, 100 metres: a single hill that rises to one high point and comes back down — that is the cross-section.
A3.4 Bodies of water and drainage basins
Example
Explain a drainage basin and describe a river system's shape.
- A drainage basin is all the land whose water drains into the same river system.
- A river system is a branching pattern of tributaries feeding a main channel.
Example
Say what sets the Great Lakes apart.
- The Great Lakes hold about one-fifth of the world's fresh surface water — their water is fresh rather than salty.
A3.5 Processes in water systems
Example
Explain what happens when a dam is built and when a glacier feeding a river shrinks.
- Dam: water backs up and floods the valley to form a reservoir.
- Glacier: the river's summer flow declines as the stored ice runs out.
Example
Explain what happens when a town over-pumps its aquifer.
- Aquifer: the underground level falls and nearby wells begin to run dry. The water cycle keeps moving water between sea, air and land; river action carves and deposits along the way.
A3.6 Climate regions
Example
Name the climate region: hot and wet all year near the equator; Winnipeg's big seasonal swings; the Sahara and central Australia.
- Tropical.
- Continental — being far inland produces big seasonal swings.
- Dry: more moisture evaporates than falls as precipitation. Deserts can even be cold.
A3.7 What shapes climate
Example
Explain why the tropics are warm and why Vancouver's winters are milder than Winnipeg's.
- Latitude: sunlight strikes the tropics more directly, concentrating its energy.
- Vancouver: the nearby ocean stores heat and softens the coastal seasons.
Example
Explain how greenhouse gases change climate.
- The gases trap extra heat, warming averages and shifting rain and storms. Elevation cools; ocean currents and prevailing winds carry warmth or cold along coasts.
A3.8 Climate graphs
Example
Read the figure: what do the line and the bars show?
- The line tracks monthly temperature; the bars show monthly precipitation.
- The line stays high all year; the bars are near zero except for a brief burst.
Example
Read the figure: what kind of place is this?
- It is a hot, dry region with only a brief wet season — Khartoum's graph. A graph that is warm and wet in every month would be near the equator, in a tropical region.
A3.9 Natural vegetation regions
Example
Name the vegetation region and its reason: Earth's largest forest belt; no trees in the far north.
- The boreal forest — it rings the high northern continents; Earth's largest forest belt.
- Tundra: the growing season is too short and deeper ground stays frozen.
Example
Name the vegetation region and its reason: grass but no forest on the prairie.
- Grasslands: they receive enough moisture for grass but too little for forests.
A3.10 What shapes vegetation regions
Example
Explain the risk of monoculture and why zebra mussels spread.
- Monoculture: the soil wears out and one pest or disease can wipe out everything.
- Zebra mussels: an introduced species multiplies unchecked because its natural enemies were left behind.
Example
Explain what clearing a slope does to its soil.
- Clearing: the nutrient layer new plants need to take root washes away. Climate and soil together decide what grows.
A3.11 How the parts interact
Example
Explain a rain shadow and why desert plants look the way they do.
- Rain shadow: air rises and drops moisture on one side of a range, then descends dry on the other.
- Desert plants: the climate's scarce moisture shapes what grows and how it grows.
Example
Explain why landform, soil and plants are one system.
- Landform, soil, and plant life work as one connected system — change one and the others shift.
Summary
- Mountains, plateaus, plains — made by plates, water, ice and people.
- Contours join equal heights; crowded means steep.
- Basins drain to one river; the Great Lakes are fresh.
- Dams, shrinking glaciers and pumping change water systems.
- Tropical, continental, dry — set by latitude, oceans, winds, elevation.
- Boreal, tundra, grassland — set by growing season and moisture.
- Rain shadows; one connected system.