Key Terms

📖 Key Terms

Natural hazard — A naturally occurring physical event (such as an earthquake, volcanic eruption, tropical storm, or flood) that poses a threat to human life, property, or livelihoods. The event only becomes a hazard when people are at risk; an identical event in an uninhabited area is a natural phenomenon, not a hazard.

Natural disaster — An event that occurs when a natural hazard strikes a vulnerable human population and causes significant loss of life, damage to property, or disruption to society that exceeds the local community's capacity to cope without outside assistance.

Risk — The probability that a natural hazard will cause harm to a specific community. Measured by the formula: Risk = Hazard × Vulnerability ÷ Capacity to Cope. High-risk environments combine a powerful hazard with a highly vulnerable, poorly prepared population.

Vulnerability — How susceptible a population is to the negative effects of a natural hazard. Determined by poverty, building quality, governance, access to healthcare, education level, and geographical accessibility. High vulnerability explains why the same physical event causes far more deaths in a LIC than in a HIC.

Resilience — The ability of a community or society to anticipate, absorb, accommodate, and recover from a natural hazard event with minimum disruption. Built through investment in preparedness, strong institutions, diverse economies, and learning from past disasters.

Tectonic hazard — A natural hazard caused by movement of tectonic plates. Includes earthquakes, volcanic eruptions, and tsunamis. Concentrated along plate boundaries and at volcanic hotspots. The Ring of Fire (around the Pacific Ocean) contains 75% of the world's active volcanoes and generates around 90% of the world's earthquakes.

Atmospheric hazard — A natural hazard caused by extreme atmospheric conditions. Includes tropical storms (hurricanes, typhoons, cyclones), tornadoes, droughts, extreme heat, and extreme cold. Becoming more frequent and intense due to climate change.

Coping capacity — The ability of a community, government, or society to manage the impacts of a natural hazard using available resources, skills, and institutions. High coping capacity (characteristic of HICs) dramatically reduces disaster mortality even when hazard magnitude is large.

Disaster Risk Reduction (DRR) — The systematic approach to identifying, assessing, and reducing hazard risks through preparedness, improved governance, resilient infrastructure, and community education. The international framework for DRR is the Sendai Framework (2015–2030), adopted by 187 UN member states.

Sendai Framework — The international agreement (adopted March 2015, Sendai, Japan) guiding global disaster risk reduction efforts to 2030. Four priorities: understanding risk, strengthening governance, investing in resilience, and enhancing preparedness. Its central target is to substantially reduce disaster mortality and the number of affected people by 2030.