The concepts of hazard, risk, vulnerability and resilience; the hazard risk equation; the factors that shape vulnerability; and the role of development and governance.

What this dot point is asking

Eduqas wants you to explain the concepts of hazard, risk, vulnerability and resilience, apply the hazard risk equation, identify the factors that shape vulnerability, and evaluate the role of development and governance in determining impact.

The answer

Hazard, risk, vulnerability and resilience

These concepts let you explain why the same physical event produces different outcomes. A hazard only becomes a disaster where it meets a vulnerable population. Vulnerability captures how exposed and unprotected people are, and resilience captures their ability to bounce back. The relationship is captured by the hazard risk equation, which makes explicit that human factors (vulnerability and capacity to cope) sit alongside the physical hazard in determining risk.

The hazard risk equation

The equation is the analytical heart of the topic. Hold the hazard constant (two magnitude $7$ earthquakes), and the impacts diverge entirely with vulnerability and capacity to cope: a quake under a poor, dense, poorly built, weakly governed city is catastrophic, while the same quake under a wealthy, well-built, well-prepared city causes far less harm. This is why Eduqas wants you to reason with the equation rather than assume that the bigger event is always the worse disaster.

Factors shaping vulnerability and the role of development

The factors that raise vulnerability and lower capacity to cope are largely set by development and governance. Poverty limits building quality, emergency services and the ability to recover; high population density in hazard zones (cities on faults, communities near volcanoes) raises exposure; weak or corrupt governance means poor planning, unenforced building codes and a slow, disorganised response; and low education, weak warning systems and poor risk perception leave people unprepared. Wealthy, well-governed countries can afford resilient buildings, monitoring, drills and rapid response, so they generally suffer fewer deaths (though greater economic losses). Eduqas expects the judgement that development and governance frequently dominate the death toll, while physical factors, especially secondary hazards, set the upper limit on what even a prepared country can withstand.

Examples in context

Example 1. Haiti earthquake (2010). A magnitude $7.0$ shallow quake near densely populated Port-au-Prince, in one of the world's poorest, most weakly governed countries, killed an estimated $200{,}000$ to $300{,}000$ people. High vulnerability (weak buildings, dense poverty, no enforced codes) and low capacity to cope (limited emergency services, weak governance, dependence on slow aid) turned a moderate quake into a catastrophe, with cholera and displacement persisting for years. Haiti is the classic Eduqas case for how low development and poor governance, not magnitude, drive a high death toll, the human side of the risk equation.

Example 2. The contrast with Tohoku, Japan (2011). Japan's magnitude $9.0$ quake, about $1{,}000$ times more powerful, caused far fewer deaths from shaking because low vulnerability (aseismic buildings, drills, codes) and high capacity to cope (wealth, warning systems, organised response) protected the population; the roughly $18{,}000$ deaths came overwhelmingly from the tsunami, a secondary hazard that overwhelmed defences. Pairing Tohoku with Haiti is the standard Eduqas contrast: it shows development reducing primary-hazard deaths while physical secondary hazards set the limit, supporting a balanced judgement that impact is the product of physical and human factors.

Try this

Q1. State the hazard risk equation. [2 marks]

• Cue. Risk equals hazard multiplied by vulnerability divided by capacity to cope.

Q2. Explain why a lower-magnitude earthquake can cause more deaths than a higher-magnitude one. [3 marks]

• Cue. If the lower-magnitude quake strikes a place with high vulnerability (poor buildings, dense poverty) and low capacity to cope (weak governance, limited services), its death toll can far exceed that of a larger quake in a developed, well-prepared country.