The big idea: A hazard is a natural event that could harm people. The risk it poses depends on who and what is exposed, and how well they can cope - not just the event's size.
The risk equation: Geographers use a simple idea: Risk = Hazard x Vulnerability / Capacity to cope. The same earthquake hits a rich, prepared city far more gently than a poor, unprepared one.
Vulnerability - the key term
- How susceptible people are to harm.
- Driven by economic, social, demographic and political factors.
- Not by the geology alone.
Key terms for hazard risk
- Hazard - a natural event (earthquake, eruption, landslide) that threatens people.
- Risk - the probability of harmful consequences from a hazard.
- Vulnerability - how susceptible a community is to harm from a hazard.
- Capacity to cope - the ability to prepare for, withstand and recover (wealth, governance, planning).
- Exposure - the people and property in the place where the hazard strikes.
- Risk perception - how seriously people judge the threat - which shapes whether they prepare.
Risk is not just the hazard: Two earthquakes of the same magnitude can cause wildly different damage. The difference is vulnerability and capacity to cope - wealth, building codes, governance, density and preparedness - not the size of the shake.
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How this is tested: The figure you read first is usually a comparison chart or table of two named events - their deaths, building damage or a vulnerability index side by side.
What the questions ask
Identify
Identify the more vulnerable place.
Estimate
Estimate a value off the axis or key.
Explain [3]
The marks then come on short Explain [3] parts: how one economic, social, demographic or political factor changes risk.
Name it, then develop it: Always name the factor and develop how it raises or lowers vulnerability.
Read the key first. A higher score means more vulnerable. Which event sits higher on every bar?
Interactive diagram
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Identify the more vulnerable event and estimate how much higher it scores for weak building codes.
Model answer plan
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Same magnitude, very different impacts - why vulnerability matters
| Factor | Haiti 2010 (Mw 7.0) | Christchurch 2011 (Mw 6.3) |
|---|---|---|
| Deaths | ~220,000 | 185 |
| Wealth (development) | Low-income, very poor | High-income, wealthy |
| Buildings | Unreinforced, no enforced codes | Strict, enforced building codes |
| Governance / preparedness | Weak government, little planning | Strong response, drills, insurance |
| Population & density | Dense, fast-growing capital | Lower density, planned city |
| Outcome | Catastrophic - high vulnerability | Serious but survivable - low vulnerability |
Read the contrast, not just one column: When a table compares two events, the marks come from the comparison: a similar magnitude but a huge gap in deaths points straight to vulnerability (wealth, building codes, governance) rather than the hazard itself.
What drives vulnerability
- Economic - wealth funds strong buildings, insurance and recovery; poverty forces people into flimsy homes on risky land.
- Social - education, risk perception, healthcare and community ties shape who survives and recovers.
- Demographic - the elderly and very young struggle to flee or recover; high density raises exposure.
- Political - good governance brings codes, warnings and planning; weak governance leaves people unprotected.
Using the table above, explain how economic conditions changed the impact of two earthquakes of similar magnitude.
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Top marks need named events. Vulnerability is shaped by economic, social, demographic and political factors - and the same hazard can devastate one community while barely touching another.
Vulnerability factors and how they change risk
| Factor | Raises vulnerability | Lowers vulnerability |
|---|---|---|
| Wealth / economy | Poverty - flimsy homes, no insurance | Wealth - strong buildings, insurance, recovery funds |
| Governance / politics | Weak state - no codes or warnings | Strong state - enforced codes, warning systems |
| Age structure | Many elderly / very young - hard to flee | Working-age, mobile population |
| Education / awareness | Low awareness - hazard seen as fate | Drills, education, high risk perception |
| Density | Crowded settlement - high exposure | Lower density, planned land use |
Haiti 2010 - poverty and weak governance: The 2010 Haiti earthquake (Mw 7.0) killed around 220,000 people. A poor economy meant unreinforced housing, weak government meant no enforced building codes, and a dense capital meant huge exposure. Recovery was crippled - many displaced people lived in camps for years because the scale of devastation, weak institutions and lack of funding blocked rebuilding.
Eyjafjallajokull 2010 (Iceland)
- The eruption caused no local deaths.
- A wealthy, prepared state with monitoring and good planning.
Nevado del Ruiz 1985 (Colombia)
- Killed about 23,000 in the town of Armero.
- Warnings were poor and ignored, so a lahar buried a community that could have been evacuated.
Eyjafjallajokull 2010 & Nevado del Ruiz 1985 - capacity matters: Low capacity to cope, not eruption size, drove the disaster.
Explain two reasons why displaced people may be unable to return home for a long time after a major earthquake.
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Suggest one reason why residents might underestimate the risk of a geophysical hazard where they live.
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See the answer broken into clear points, with guidance on how each point earns marks.
Always give the mechanism: Do not just name a factor - explain how it changes vulnerability. Poverty -> flimsy housing + no insurance -> buildings collapse + slow recovery -> higher death toll.
Gender, isolation, and magnitude-frequency
- Gender — where women have less access to warnings, education or the right to leave home, they can be more vulnerable; in many villages hit by the 2004 Indian Ocean tsunami, more women than men died.
- Isolation — remote mountain villages and island communities wait longer for rescue and aid, as many did after the 2015 Nepal earthquake.
- Magnitude and frequency — small events are common, very large ones rare; managers plan for events of a chosen recurrence (for example a once-in-500-year earthquake), and rare giants are hardest to prepare for because people forget the last one.
- Distribution — most earthquakes and volcanoes lie along plate margins such as the Pacific Ring of Fire; mass movements cluster on steep, wet slopes.
Where and when an event strikes
- Time of day — the Kobe earthquake (Japan, 1995) struck at 5:46 am, when most people were asleep in older wooden houses that collapsed, and over 6,000 died. In Sichuan (China, 2008) the 2:28 pm quake caught children in class, and many schools collapsed.
- Urban location — dense cities expose more people and buildings to one event, and fires can spread (Kobe); but they also have hospitals and rescue teams close by.
- Rural location — fewer people are exposed, but homes are often self-built, and aid takes longer to arrive.
- Isolation — after the Gorkha earthquake (Nepal, 2015), landslides cut the mountain roads, so remote villages waited days for help reached only on foot or by helicopter.
How this is tested - the [10] Examine essay: Paper 1 Option D ends with a 10-mark Examine essay, marked on markbands.
The recurring version asks
- Why two events of similar magnitude cause very different human impacts.
- Or how economic vs social factors determine vulnerability.
Top band needs
- Accurate terms.
- A range of developed factors (economic, social, demographic, political).
- Named case studies with data.
- A weighing of relative importance.
- A clear judgement.
Examine why two earthquakes of similar magnitude can produce very different human impacts.
Model answer plan
See the answer broken into clear points, with guidance on how each point earns marks.