Understanding disaster risk: Key concepts
From deterministic and probabilistic risk to intensive and extensive risk, explore key concepts in disaster risk reduction.
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.
Deterministic risk considers the impact of a single risk scenario, whereas probabilistic risk considers all possible scenarios, their likelihood and associated impacts.
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.
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.
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.
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.
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 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.
Compound risk is the risk that two or more hazards or risk drivers interact, either simultaneously or consecutively, producing impacts greater than the sum of individual events, and complicating response and recovery.
Cascading risk is the probability of a chain reaction resulting from a hazard or failure which triggers interconnected impacts that may escalate across systems and sectors.
This is part of the Understanding Disaster Risk section on PreventionWeb, which explains the concept of disaster risk, risk assessment, and management strategies, emphasizing collaboration among stakeholders for effective disaster risk reduction.