Understanding disaster risk:
foundational concepts and principles

Explore the encyclopedia of disaster risk reduction

Reading the materials in this section, you will learn to understand the concept of disaster risk, risk assessment, management strategies, and the importance of collaboration among stakeholders for effective disaster risk reduction.

Why reducing risk matters

Saving lives, protecting infrastructure, safeguarding economies, preserving the environment and building resilience.

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Disaster losses and statistics
While absolute economic losses are concentrated in high-income countries, the human cost of disasters falls overwhelmingly on low and middle-income countries.
Disaster risk solutions
Concrete innovations, inventions, and strategies are reducing the impacts of disasters worldwide. These practical case studies and proven strategies address various aspects of disaster risk.
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The business case for DRR
Investing in disaster risk reduction (DRR) saves lives and money and future-proofs our development gains.

Components of risk

Disaster risk is the consequence of the interaction between a hazard and the characteristics that make people and places vulnerable and exposed.

  • Disaster Risk
    Disaster risk is expressed as the likelihood of loss of life, injury or destruction and damage from a disaster in a given period of time.
  • Hazard
    A hazard is a process, phenomenon or human activity that may cause loss of life, injury or other health impacts, property damage, social and economic disruption or environmental degradation. Hazards may be natural, anthropogenic or socionatural in origin.
  • Vulnerability
    The characteristics determined by physical, social, economic and environmental factors or processes which increase the susceptibility of an individual, a community, assets or systems to the impacts of hazards.
  • Exposure
    The situation of people, infrastructure, housing, production capacities and other tangible human assets located in hazard-prone areas.
Disaster myths
Seven myths debunked
In times of disaster, myths and misinformation can spread like wildfire. To help you keep your head above the floodwaters of myth and misconception, the PreventionWeb editors have put together a life-raft of truths.

Risk drivers

Risk is influenced by the decisions we make. From climate change to poor urban planning, it is critical to understand and address risk drivers to curb disaster risk.

  • Climate change
    Climate change can increase disaster risk in a variety of ways - by altering the frequency and intensity of hazard events, affecting vulnerability to hazards, and changing exposure patterns.
  • Environmental degradation
    Environmental degradation is both a driver and consequence of disasters, reducing the capacity of the environment to meet social and ecological needs.
  • Globalized economic development
    This has increased vulnerability to disasters in some cases, whilst increasing exposure to hazards in others as more (and often more valuable) assets are developed in hazard-prone areas.
  • Poverty and inequality
    Poverty is both a driver and consequence of disasters, and the processes that further disaster risk related poverty are permeated with inequality.
  • Poorly planned urban development
    Whether or not disaster risk is factored into investment decisions in urban development will have a decisive influence on the future of disaster risk reduction.
  • Weak governance
    Investment environments in which public sector actors do not assume their roles and responsibilities.

Key concepts

From deterministic and probabilistic risk to intensive and extensive risk, explore key concepts in disaster risk reduction.

  • Anticipatory action
    Anticipatory action allows humanitarians and affected communities to make informed decisions ahead of a humanitarian crisis – saving time and money; preventing displacement, disease, loss of livelihood; and preserving the dignity of those affected.
  • Capacity
    Capacity refers to all the strengths, attributes and resources available within a community, organization or society to manage and reduce disaster risks and strengthen resilience.
  • Conducting simulation exercises
    Simulation exercises help prepare communities and allow for stress testing plans and systems for effective response. Systems, emergency procedures, contingency plans, response mechanisms, and equipment are tested in these exercises.
  • Deterministic and probabilistic risk
    Deterministic risk considers the impact of a single risk scenario, whereas probabilistic risk considers all possible scenarios, their likelihood and associated impacts.
  • Direct and indirect losses
    Losses (the result of being deprived of something) are a measure (quantified or not) of the damage or destruction caused by a disaster. The impact of a disaster can, however, be much farther reaching.
  • Disaster risk reduction and disaster risk management
    The policy objective of anticipating and reducing risk is called disaster risk reduction (DRR). Although often used interchangeably with DRR, disaster risk management (DRM) can be thought of as the implementation of DRR, since it describes the actions that aim to achieve the objective of reducing risk.
  • Intensive and extensive risk
    Extensive risk is used to describe the risk associated with low-severity, high-frequency events, mainly but not exclusively associated with highly localized hazards. Intensive risk is used to describe the risk associated to high-severity, mid to low-frequency events, mainly associated with major hazards.
  • Resilience
    In the context of disaster risk, the ability of a system, community or society exposed to hazards to resist, absorb, accommodate, adapt to, transform and recover from the effects of a hazard in a timely and efficient manner, including the preservation and restoration of its essential basic structures and functions through risk management.
  • Scaling up DRR in humanitarian action
    Scaling up disaster risk reduction (DRR) in humanitarian and fragile contexts is critical as it complements emergency response with a focus on reducing exposure and vulnerability. DRR integration also helps to ensure that no one is left behind, as marginalization and social inequalities reinforce vulnerable populations’ exposure to disasters.
  • Sovereign risk
    If the potential occurrence of a disaster is not taken into account in the government's budget and a disaster occurs, this could entail a deficit for the country, and impact negatively on the country’s creditworthiness. A sovereign risk financing strategy aims at strengthening the capacity of the government to respond after a disaster event while protecting its fiscal balance.
  • Systemic risk
    Systemic risks involve: multiple communities, cities, regions, or countries; risks that are interconnected; effects that move from one system or network to another and are uncertain or unpredictable; and they have potentially devastating outcomes – like the collapse of entire systems and threats to society as a whole.

Risk Media hub

A toolkit for news media professionals reporting on disasters and resilience.

The toolkit provides an array of resources to help journalists tell the other side of the disaster story and raise critical questions to help societies become more resilient.

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The DRR Glossary

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Terminology on Disaster Risk Reduction
The Open-ended intergovernmental expert working group on indicators and terminology relating to disaster risk reduction was established by the General Assembly in its resolution 69/284 for the development of a set of possible indicators to measure global progress in the implementation of the Sendai Framework for Disaster Risk Reduction 2015-2030.

Engage in DRR

Knowledge base
With more than 75,000 news items, publications and other updates explore daily updates on what's happening in disaster risk and resilience.

Implementing the Sendai Framework
What is the Sendai Framework?
A global blueprint aiming to substantially reduce disaster risk and losses in lives, livelihoods, and health, while also enhancing resilience and promoting sustainable development.

Hazards do not have to turn into disasters.

To break the vicious cycle of "Disaster, respond, recover, repeat.", we need a better understanding of disaster risk, in all its dimensions.

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