Hazard Risk and Vulnerability - TCE Geography (Tasmania)
“Hazard risk combines the probability of an event with exposure and vulnerability, so impacts fall unevenly on people and places.”
Risk is the chance that a hazard causes harm. It combines the probability of an event with the exposure of people and assets and their vulnerability, the capacity to anticipate, cope with and recover from it. Because vulnerability varies, the same hazard produces very unequal impacts.
What this dot point is asking
Understanding why hazards harm some people far more than others is central to the unit. The key idea is that risk is not just about the physical event. Risk is commonly expressed as a relationship between the probability or hazard, the exposure of people and assets, and their vulnerability. A high-magnitude event in an unpopulated area carries low risk, while a moderate event in a densely settled, poorly prepared community can be catastrophic. This explains why disasters concentrate harm on the poor and marginalised even when the physical hazard is identical.
Exposure refers to the people, property, infrastructure and environments located where a hazard can affect them. Building on a floodplain, a coastal dune or in the bushland-urban interface increases exposure. Vulnerability is the susceptibility to harm and the limited capacity to cope and recover. It has physical, social, economic and environmental dimensions. Physical vulnerability includes weak buildings and poor infrastructure. Social vulnerability includes age, health, isolation, language and access to information; the very old, the very young and people with disabilities are often most at risk. Economic vulnerability includes poverty and lack of insurance or savings, which slows recovery.
The characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard, including limited capacity to anticipate, cope with, resist and recover from impacts.
The flip side of vulnerability is resilience and adaptive capacity: the resources, knowledge, social connections and institutions that help a community absorb a shock and bounce back. Wealthier, better-organised communities with strong warning systems, building codes and insurance generally have higher resilience. This is why high-income countries often suffer high economic losses but fewer deaths, while low-income countries may suffer fewer dollar losses but far higher death tolls from a comparable event.
Compare two earthquakes of similar magnitude: the 2010 Haiti earthquake killed an estimated hundreds of thousands amid poverty, weak buildings and limited emergency capacity, while a comparable event in a high-income, well-prepared region typically causes far fewer deaths. The difference is vulnerability and resilience, not the physical hazard.
Risk perception also shapes outcomes. People do not respond to objective risk alone but to how they perceive it, which is influenced by experience, culture, trust in authorities, the visibility of the hazard and the perceived benefits of living in a hazardous area. Many Tasmanians choose to live in scenic bushland or coastal settings despite bushfire and erosion risk because they value the lifestyle and may underestimate the danger, especially if no major event has occurred in living memory. Misjudged perception can lead people to ignore warnings or build in dangerous locations.
Tasmania offers clear examples. In the bushland-urban interface around Hobart and in towns such as those affected by past fires, exposure is high where housing meets flammable vegetation, and vulnerability rises for elderly residents, people without vehicles and those on single-access roads. The 2016 floods exposed properties and farmland on floodplains, with recovery shaped by insurance and resources. Coastal communities on low-lying or eroding shores face rising exposure as sea levels rise. Globally, vulnerability patterns explain why cyclones in the Bay of Bengal or earthquakes in poorer regions cause disproportionate harm.
A frequent stimulus is a table of deaths, people affected and economic losses for hazards in different countries. Work it in steps.
Step 1: read the units and cases
Confirm what each column measures (deaths, dollars, magnitude) and which country is high-income and which is low-income.
Step 2: calculate the contrast
Compare like with like. If one quake kills 220,000 and a similar-magnitude event elsewhere kills 60, the death ratio is over to , while economic losses may run the other way.
Step 3: attribute the difference
Assign deaths to vulnerability (building quality, density, poverty, emergency capacity) and dollar losses to the value of exposed assets and insurance, holding magnitude roughly constant.
Step 4: state the geographic point
Conclude that the divergence is produced by human exposure and vulnerability, not by the physical hazard. This evidence-led reasoning is what the marks reward.
Assuming the largest physical events always cause the worst disasters ignores vulnerability. A smaller hazard striking a highly vulnerable, exposed population can be far more deadly than a large one striking a resilient, well-prepared community. Always analyse exposure and vulnerability, not just magnitude.
For assessment, be able to break a scenario into probability, exposure and vulnerability, identify which social and economic groups are most vulnerable and why, and discuss how risk perception influences behaviour. This analysis sets up the evaluation of risk-management strategies, where the goal is to reduce exposure and vulnerability and to build resilience across all groups, not just the well-resourced.
Exam-style questions
Questions in the style of TASC exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Practice8 marksCompare the deaths and economic losses from two earthquakes of similar magnitude that you have studied, one in a high-income and one in a low-income country. Describe the differences, then explain them using the concepts of exposure and vulnerability.Show worked answer →
An 8 mark source-and-explain response needs accurate data description followed by causal explanation.
Describe the data. Quote the figures: the low-income country recorded far higher deaths while the high-income country recorded higher economic losses, despite similar magnitude. State the contrast precisely from the table.
Explain with concepts. Use the relationship that risk combines probability, exposure and vulnerability. Higher death tolls reflect greater social and physical vulnerability (weak buildings, dense settlement, limited emergency capacity, poverty), while higher dollar losses in the wealthy country reflect higher-value exposed assets and insurance coverage.
Markers reward exact use of the table, correct use of exposure and vulnerability, and the insight that the physical hazard was similar, so the difference is human, not geophysical.
Practice12 marksAnalyse why the impacts of a hazard fall unevenly on different groups, and evaluate the view that vulnerability matters more than the size of the physical event. Use specific examples.Show worked answer →
A 12 mark response needs the uneven-impact mechanism, a weighed argument and a judgement.
Uneven impact. Break risk into exposure (who and what is in harm's way) and vulnerability (physical, social, economic capacity to cope). The very old, very young, isolated, poor and uninsured suffer most, as the 2010 Haiti earthquake showed against a comparable event in a prepared, high-income region.
Weigh the view. Concede that magnitude sets an upper limit on potential harm, but argue that for a given event vulnerability and exposure largely determine the human outcome, and that risk perception shapes whether warnings are heeded.
Judgement. Conclude that vulnerability usually matters more than magnitude for human loss, while both interact. Markers reward the risk relationship, named contrasting cases and a clear, justified position.