O Level Geography: The Natural Environment — Revision Notes (Cambridge 2217)

Related: Theme 2 study guide

Condensed, exam-focused notes for Theme 2 of Cambridge O Level Geography (2217), 2026 series.

2.1 Earthquakes and volcanoes

• Caused by plate movement at boundaries (diverging, converging, sliding past).
• Earthquakes: stress builds along a fault and releases suddenly; effects include ground shaking, tsunamis, building collapse.
• Volcanoes: magma reaches the surface, typically at converging or diverging boundaries; effects include lava flows, ash fall, pyroclastic flows.
• Management: building codes, early-warning systems, evacuation planning — always separate the physical cause (plate boundary type) from the human response (management).

2.2 Rivers

Course	Dominant process	Typical landform
Upper	Vertical erosion	V-shaped valley, waterfall
Middle	Lateral erosion	Meander
Lower	Deposition	Floodplain, delta

• Flood management: hard engineering (dams, levees, channel straightening) vs soft engineering (floodplain zoning, upstream afforestation) — always state which category a named strategy belongs to.

2.3 Coasts

• Erosion processes: hydraulic action, abrasion, attrition, solution.
• Erosional landforms: headlands and bays, cliffs, wave-cut platforms, caves, arches, stacks (formed where softer rock erodes faster than harder rock).
• Depositional landforms: beaches, spits.
• Coral reefs and mangrove swamps: distinct ecosystems valued for biodiversity and natural coastal protection against erosion/storm surges.

2.4 Weather

• Weather = short-term, day-to-day state of the atmosphere. Climate = long-term average pattern.
• High pressure: generally settled, dry, clear conditions.
• Low pressure: generally cloud, rain, stronger winds.
• Know how weather elements (temperature, rainfall, wind, pressure) are measured.

2.5 Climate and natural vegetation

• Tropical rainforest: high, consistent rainfall and temperature; dense, layered canopy vegetation competing for light. Threat: deforestation.
• Hot desert: very low rainfall, wide diurnal temperature range; vegetation (e.g. cacti) stores water, reduces leaf surface area to limit water loss. Threat: overgrazing, irrigation-driven degradation.
• Always link climate → vegetation adaptation → human impact as one connected chain, not three separate facts.

Exam technique for this theme

Treat this theme as a set of process-then-landform pairs rather than a list of features to memorise in isolation. For both rivers and coasts, always state the formative process (erosion, transportation or deposition) before naming the landform it produces, since Paper questions consistently ask candidates to explain a labelled landform by its process, not simply name it — a landform named without its process earns partial credit at best. Practise sketching and annotating a labelled river long profile and a labelled coastal cross-section from memory, since diagram-based recall is directly examined. For earthquakes and volcanoes, keep the physical cause (plate boundary type) and the human response (hazard management) as two separate mental categories, because exam questions frequently ask for one without the other, and blending them together in an answer costs marks even when both parts are individually correct.

Case study preparation

Every sub-topic in this theme is more securely revised with at least one named, real-world case study attached, since exam questions frequently ask candidates to “describe the impacts of a named earthquake, volcanic eruption, or flood event” rather than only testing generic process knowledge. For each of earthquakes, volcanic eruptions, river flooding, and coastal management, prepare one specific named example with a handful of concrete facts (location, date, scale, and the specific management response used) rather than relying on generic process description alone — a generic answer about “an earthquake” without any named location or date will not access the marks reserved for case-study detail even if the process explanation itself is accurate.

Comparing the two climate zones directly

Because 2.5 is often examined by asking candidates to compare tropical rainforest and hot desert climates and their vegetation rather than describe each separately, practise building direct comparison statements rather than two separate descriptions. For instance: rainforest vegetation forms a dense, multi-layered canopy competing for light in conditions of abundant water, while desert vegetation such as cacti reduces leaf surface area and stores water internally in conditions of severe water scarcity — both adaptations respond to the dominant environmental stress of their climate, but that stress is opposite in each case (excess resource competition versus resource scarcity). Human impact follows the same comparative logic: deforestation removes rainforest’s protective canopy and accelerates soil erosion and biodiversity loss, while overgrazing and irrigation-driven degradation in deserts can trigger desertification of already marginal vegetation cover.

Sketching diagrams from memory

Because this theme is examined partly through labelled diagram recall, practise sketching a river’s long profile and a coastal cross-section entirely from memory, then checking your sketch against the study guide’s version and correcting any missing label. Repeating this until the sketch is accurate without reference builds a genuinely reliable exam skill, since a candidate who can label a diagram when shown one but cannot reproduce it unprompted is more exposed than a candidate who has practised the recall itself.

Self-test

1. Name the three ways plates can interact at a boundary.
2. What is the dominant process and typical landform in a river’s middle course?
3. Name two coastal erosional landforms and one depositional landform.
4. Contrast high-pressure and low-pressure weather characteristics.
5. Give one specific vegetation adaptation for hot desert climates and the stress it responds to.

Answers: 1. Diverging, converging, sliding past (transform). 2. Lateral erosion; meander. 3. Erosional: headland/bay, cliff, wave-cut platform, cave/arch/stack (any two). Depositional: beach or spit. 4. High pressure = settled/dry/clear; low pressure = cloudy/rainy/windy. 5. Reduced leaf surface area (e.g. cacti spines) — responds to water scarcity/heat stress.