OxfordAQA IGCSE Geography: Living with the Physical Environment — Revision Notes

Condensed for the final weeks. For the full explanation, use the Living with the Physical Environment study guide.

Tectonic hazards

Plate margins — learn the movement, the landform and an example together:

Margin	Movement	Result
Constructive (divergent)	Plates move apart	Mid-ocean ridges, shield volcanoes, mild earthquakes — Mid-Atlantic Ridge
Destructive (convergent)	Oceanic subducts under continental	Deep trenches, composite volcanoes, violent earthquakes — Nazca/South American
Collision	Two continental plates meet	Fold mountains, strong earthquakes, no volcanoes — Himalayas
Conservative (transform)	Plates slide past	Powerful earthquakes, no volcanoes — San Andreas Fault

Collision and conservative margins produce no volcanic activity because no crust is being destroyed or created. That is a frequent question.

Why people live in hazardous areas: fertile volcanic soils, geothermal energy, mineral deposits, tourism, family and cultural ties, employment, and the perception that a major event is unlikely in their lifetime.

Primary and secondary effects

• Primary — caused directly by the hazard: buildings collapse, people killed by falling debris, roads cracked.
• Secondary — caused by the primary effects: fires from ruptured gas mains, disease from contaminated water, homelessness, unemployment, tsunamis.

A question asking for secondary effects wants consequences of consequences. Listing primary effects is the standard way to lose the marks.

Responses

Immediate — search and rescue, emergency shelter, medical treatment, restoring water and power, foreign aid. Long-term — rebuilding to improved standards, repairing infrastructure, improving monitoring and warning, economic recovery.

Why LICs suffer greater impacts than HICs: weaker building regulations and enforcement, less monitoring and warning technology, poorer emergency services, less money for preparation and recovery, denser informal settlements, and slower economic recovery. The hazard is the same; the vulnerability differs.

Reducing risk — the four Ps

	Meaning
Prediction	Monitoring seismometers, gas emissions, ground deformation
Protection	Earthquake-resistant buildings, sea walls, lava diversion
Preparation	Drills, education, emergency supplies, evacuation plans
Planning	Land-use zoning that avoids the highest-risk areas

Earthquakes cannot be reliably predicted; volcanic eruptions often can, from monitoring data. That contrast is frequently examined.

Weather hazards

Tropical storms require sea temperatures above 27 °C, ocean depth of at least 60 m, low wind shear, and a location roughly 5–30° from the equator (some Coriolis effect is needed to generate rotation, so storms do not form on the equator itself).

Structure: a calm, clear, low-pressure eye at the centre, surrounded by the eyewall where the most intense winds and rainfall occur, then spiralling rainbands.

Storms weaken over land because they lose the warm ocean water that supplies energy through evaporation, and friction slows them.

Climate change is expected to increase storm intensity and extend the areas affected, as more of the ocean exceeds 27 °C — the evidence for a change in overall frequency is less clear, and saying so shows judgement.

Climate change

Natural causes: orbital (Milankovitch) cycles, solar output variation, volcanic eruptions injecting ash and aerosols. Human causes: burning fossil fuels, deforestation, agriculture (methane from livestock and rice), industry and cement production.

The enhanced greenhouse effect is the mechanism: greenhouse gases absorb and re-radiate outgoing longwave radiation, and higher concentrations trap more heat.

• Mitigation — reducing the causes: renewable energy, afforestation, carbon capture, international agreements.
• Adaptation — coping with the effects: flood defences, drought-resistant crops, changing agricultural patterns, managed retreat.

Marks are commonly lost by putting a strategy in the wrong category. Planting trees is mitigation; building a sea wall is adaptation.

Ecosystems

Producers → primary consumers → secondary consumers, linked by food chains and webs, with decomposers returning nutrients to the soil.

Tropical rainforest — hot and wet year-round, so growth is continuous and biodiversity is extremely high. Adaptations: buttress roots for stability in thin soils, drip tips to shed heavy rain, lianas and epiphytes to reach light, and a dense canopy. Nutrients are held in the biomass, not the soil — which is why cleared land becomes infertile within a few years.

Hot desert — very low, unreliable rainfall and a large diurnal temperature range. Adaptations: deep or wide-spreading roots, water storage in stems, waxy or spiny leaves reducing transpiration, and nocturnal animal behaviour.

Causes of deforestation: logging, cattle ranching, commercial farming, mineral extraction, road building, hydroelectric schemes, population pressure. Impacts: biodiversity loss, soil erosion, disrupted water cycle, reduced carbon storage, displacement of indigenous people — but also employment, exports and development. A strong answer acknowledges both, then judges.

Exam traps

• Giving primary effects when asked for secondary.
• Saying volcanoes occur at collision or conservative margins.
• Confusing mitigation with adaptation.
• Claiming earthquakes can be predicted.
• Saying rainforest soils are fertile — nutrients are in the biomass.
• Writing generic answers without named places, dates and figures. Case study detail is where the top band lives.

Self-test

1. Which two plate margins have no volcanic activity, and why?
2. Distinguish primary from secondary effects with one example of each.
3. Give three reasons LICs suffer greater impacts than HICs.
4. State three conditions required for a tropical storm to form.
5. Classify as mitigation or adaptation: afforestation, sea walls, drought-resistant crops, carbon capture.

Answers: 1. Collision and conservative — no crust is created or destroyed at either, so there is no magma generation. 2. Primary is caused directly by the hazard, such as buildings collapsing; secondary results from the primary effects, such as fires from ruptured gas mains. 3. Weaker building regulations, less monitoring and warning technology, poorer emergency services, less money for recovery, denser informal settlements — any three. 4. Sea temperature above 27 °C, ocean depth of at least 60 m, low wind shear, and a location 5–30° from the equator — any three. 5. Afforestation and carbon capture are mitigation; sea walls and drought-resistant crops are adaptation.