12ial-Hazards-Distrbution Human Factors

​Global Hazard Distribution: Human Factors and Global Risk

By Aimee Cooper

​Human Factors in Global Hazard Distribution

​Physical exposure explains where hazards occur, but human geography determines how damaging they become.

​Lesson Objectives

​By the end of this lesson you should be able to:

Explain how development, population density, accessibility and governance shape disaster impact.

Describe global patterns shown by the World Risk Index.


Evaluate why countries with similar hazard exposure experience different outcomes.

Open Ended

1 Which plate boundary produces deep quakes?
2 Where are most cyclones found?
3 Give one region of persistent drought.
4 Name one multi-hazard zone.
5 Why are some areas largely hazard-free?

​Transition

​Physical processes dictate where hazards originate, yet the toll they exact depends on people: where they live, how they build, and how governments prepare. Two events of similar magnitude can yield dramatically different losses because of these social and economic contrasts.

​Level of Development

​The level of development is the strongest determinant of vulnerability.

In high-income nations, strict building codes, comprehensive insurance and resilient infrastructure absorb shocks.

Japan’s 2011 Tōhoku earthquake and tsunami caused over US $200 billion in losses but fewer than 20 000 deaths—remarkably low given the scale—because of robust engineering and efficient emergency systems.

In contrast, Haiti’s 2010 quake of comparable magnitude destroyed much of Port-au-Prince and killed more than 200 000 people. Weak construction, overcrowding, limited medical care and scarce financial reserves magnified losses.

Open Ended

What do you think this cartograph shows?

​Economic Loss and GDP Proportion

​Disasters often cost the most in absolute terms in rich countries but the most proportionally in poor ones. A $10 billion storm represents under 1 % of US GDP but can exceed 5 % of GDP for nations such as Mozambique or Nepal. High-income states can replace assets and insure losses; low-income states may lose decades of investment.

​Population Density

​Population density dictates the scale of exposure. Cities like Manila, Dhaka and Tokyo concentrate millions within zones of recurring hazard. High density magnifies potential casualties, yet dense, well-planned cities can also speed recovery through efficient transport and communication networks. Therefore density alone does not create risk—its effect depends on planning and governance.

Open Ended

Which factor converts high exposure into high risk in many megacities?

Open Ended

Identify three collision zones where dense populations coincide with multiple hazards (e.g. Philippines, California, Bangladesh).
For each, explain briefly why people remain in these locations despite repeated danger.

​Accessibility and Isolation

​Accessibility controls how quickly aid arrives and markets recover. Regions with airports, ports and good roads—such as coastal Japan or Florida—receive relief within hours. Remote or mountainous areas—like Nepal in 2015 or inland Papua New Guinea—can be cut off for days. Isolation multiplies secondary impacts such as disease, food shortage and displacement.

Open Ended

List two benefits of high accessibility and two disadvantages of isolation. Rank them in importance for survival within the first 72 hours after impact.

​Governance and Institutions

​Governance refers to how effectively governments, institutions and civil society manage risk.

Strong governance enforces building regulations, funds early-warning systems and coordinates relief.


Weak governance allows corruption, unsafe construction and poor communication.

Compare the 1999 Izmit (Turkey) earthquake—where corruption in the construction industry amplified losses—with California’s similar-magnitude events that caused far fewer deaths. Governance can be decisive even when income is similar.

Open Ended

If identical quakes struck Tokyo and Port-au-Prince tomorrow, which earlier decisions would determine the difference in casualties?

​Interplay of Human Factors

​Development, density, accessibility and governance rarely operate separately. They interact to produce each country’s unique risk profile. For example, the Philippines combines rapid population growth, urban poverty and exposure to numerous hazards but partly offsets this through strong community-based preparedness. In contrast, small island states such as Vanuatu have limited governance capacity and high exposure but low absolute population.

​The World Risk Index (WRI)

​The WRI integrates exposure, susceptibility, coping capacity and adaptive capacity into a single percentage score.

High values indicate countries where hazards coincide with vulnerability and low resilience.


The 2023 index ranks Vanuatu, Philippines, and Tonga among the highest-risk nations; Qatar, Finland, and Iceland among the lowest. Interpretation points: Southeast Asia and Central America contain many countries with both high hazard frequency and low coping capacity. Northern Europe and North America show high exposure but strong resilience.

Open Ended

Using an online WRI map, pick one high-risk and one low-risk country. Write a short paragraph explaining why each scores as it does.

​The global pattern reflects both physical and human geography.

High Risk: tropical and sub-tropical coastal nations—Philippines, Bangladesh, Madagascar—where hazard frequency, poverty and weak infrastructure coincide.

Medium Risk: emerging economies like Mexico and China—improving governance reduces deaths but exposure remains high.

Low Risk: wealthy temperate states—UK, Canada, Australia—face fewer hazards and possess strong response capacity.

​Regional Patterns on the WRI Map

Open Ended

Which combination creates the highest WRI score?

​Analysing Risk Inequality

​The WRI demonstrates global inequality in risk: the poorest 40 % of the world’s population account for more than 90 % of disaster-related deaths.

This disparity stems less from hazard occurrence than from social and political context.

Unequal access to safe housing, education and healthcare perpetuates vulnerability, while wealthy nations externalise much of their risk through insurance and global supply networks.

​Risk = Hazard × Vulnerability ÷ Capacity to Cope.

Open Ended

Using this table, explain in 6 marks how human factors cause contrasting impacts from similar hazards.

Open Ended

1 Which human factor most reduces vulnerability?

2 Give one reason densely populated cities remain at risk.

3 Name two countries with highest WRI scores.

4 Why can isolated areas suffer high secondary losses?

5 Explain why rich countries often record higher economic losses but lower human losses.

Open Ended

“Using examples, explain how human factors influence the impact of natural hazards.” (10 marks)
Plan two paragraphs:
1 Development + Governance (Japan vs Haiti).
2 Density + Accessibility (Philippines vs Nepal).
Mark using AO1/AO2 criteria.

​Lesson Objectives

​By the end of this lesson you should be able to:

Explain how development, population density, accessibility and governance shape disaster impact.

Describe global patterns shown by the World Risk Index.


Evaluate why countries with similar hazard exposure experience different outcomes.

​Create a 300-word report explaining how the World Risk Index combines physical and human data to represent global inequality in hazard risk.