Disasters from A to Z

Source(s): PreventionWeb
Man planting mangroves in the water in Indonesia.

Disaster risk reduction explained: explore some key terms and concepts.

Affected people

People who are affected, either directly or indirectly, by a hazardous event. Directly affected are those who have suffered injury, illness or other health effects. Indirectly affected are people who have suffered consequences, other than or in addition to direct effects (UNDRR, 2017). 

In 2021, 103.5 million people in total were affected by disasters (CRED, 2021). While absolute economic losses are concentrated in high-income countries, the human cost of disasters falls overwhelmingly on low and middle-income countries.

Build Back Better

The use of the recovery, rehabilitation and reconstruction phases after a disaster to increase the resilience of nations and communities through integrating disaster risk reduction measures, into the restoration of physical infrastructure and societal systems, and into the revitalization of livelihoods, economies and the environment (UNDRR, 2017). 

Build back better has become a powerful term used by stakeholders to embody various disaster recovery projects. It’s important to ask ourselves, what the term means in each case, and what the recovery priorities are.

Critical infrastructure

The physical structures, facilities, networks and other assets which provide services that are essential to the social and economic functioning of a community or society (UNDRR, 2017). 

Day-to-day life depends on infrastructure and its services, including supply-chains, electricity, water and sanitation, and information networks. In the face increasing extreme weather events, these systems are under increasing threat. The Principles for Resilient Infrastructure developed by UNDRR (2022) are guidelines aiming to raise awareness and set an understanding of what constitutes “resilient infrastructure”.


A serious disruption of the functioning of a community or a society at any scale due to hazardous events interacting with conditions of exposure, vulnerability and capacity, leading to one or more of the following: human, material, economic and environmental losses and impacts (UNDRR, 2017). 

It’s important to remember that disasters are not natural, they result from human choices.

Early warning

An integrated system of hazard monitoring, forecasting and prediction, disaster risk assessment, communication and preparedness activities systems and processes that enables individuals, communities, governments, businesses and others to take timely action to reduce disaster risks in advance of hazardous events (UNDRR, 2017). 

Multi-hazard early warning systems address several hazards that may occur alone, simultaneously, or cascadingly. A recent report (2022) warns that half of the countries globally are not protected by multi-hazard early warning systems.

Forecast-based financing

Funding that is secured well in advance, along with a response plan that is activated by predetermined triggers. Once the trigger threshold is reached, the funding is immediately available and the assistance activities can begin, without delay. This means that obstacles to reaching a quick decision can be avoided during the critical early stages of the crisis. Forecast-based financing (FbF) is used in anticipatory action which is a pre-emptive humanitarian intervention to prevent loss of lives and livelihoods.

Gender inequality

Gender inequalities, which exist in every society, result in gender-differentiated disaster impacts. The specific needs and risks faced by women and girls, including those related to sexual and reproductive health, gender-based violence, and unpaid care and subsistence work are rarely prioritized in disaster risk reduction, and women are inadequately represented in disaster risk reduction leadership and decision making.


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 (UNDRR, 2017). Hazards are often categorized by whether they are natural (sometimes termed physical) or technological (sometimes called man-made or human-induced). The term 'peril' is sometimes used instead of hazard, particularly in the insurance industry.

Indigenous knowledge

Indigenous peoples’ understanding of disaster risk  taps into a wealth of traditional knowledge and folklore reaching back many generations. Across the world, local and national governments have begun to realise the benefits of incorporating indigenous knowledge and traditional techniques into their disaster risk reduction and resilience strategies, while indigenous communities benefit from incorporating modern science and technology into their customary approaches.


Total economic impact from disasters that consists of direct economic loss and indirect economic loss (UNDRR, 2017). Traditionally, the recording of disaster losses and damages starts at the impact level by the national disaster risk management offices. Recent progress in strengthening the data ecosystem for tracking hazardous events and disaster losses and damages points to the need to harness the comparative advantage of organisations to inform a range of services. We cannot reduce risk effectively if we cannot measure disaster losses.


Coastal ecosystems such as mangrove trees can act as natural barriers to waves and storm surges and reduce flood damages to people and property. Mangroves’ roots intertwine to form a dense thicket above water that breaks waves and helps blunt the force of an incoming wave’s energy. According to a report, mangroves are potentially providing a coastal protection (adaptation) service to at least 5.3 million people, such as in this community in Indonesia.

Nature-based Solutions

Nature-based Solutions are actions to protect, sustainable manage, and restore natural or modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits (IUCN). The reduction of the capacity of the environment to meet social and ecological objectives and needs is described as environmental degradation. This degradation and the associated decline of ecosystems and their invaluable services (the benefits we obtain) are driving disaster risk.


The knowledge and capacities developed by governments, response and recovery organizations, communities and individuals to effectively anticipate, respond to and recover from the impacts of likely, imminent or current disasters (UNDRR, 2017). A preparedness plan establishes arrangements in advance to enable timely, effective and appropriate responses to specific potential hazardous events or emerging disaster situations that might threaten society or the environment. 


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 (UNDRR, 2017).

Systemic risk

Systemic risk is associated with cascading impacts that spread within and across systems and sectors (e.g. ecosystems, health, infrastructure and the food sector) via the movements of people, goods, capital and information within and across boundaries (e.g. regions, countries and continents). The spread of these impacts can lead to potentially existential consequences and system collapse across a range of time horizons.

Transboundary risks

Greater connectivity between countries means that disaster impacts in one country can affect other parts of the world via at least four types of risk ‘pathways’: biophysical, trade, people and financial. Similarly, adaptation measures in one part of the world can have positive or negative effects elsewhere – for example by affecting supply chains or diverting international watercourses for irrigation.

Underlying risk drivers

Processes or conditions, often development-related, that influence the level of disaster risk by increasing levels of exposure and vulnerability or reducing capacity (UNDRR, 2017).

These include poverty and inequality, climate change and variability, unplanned and rapid urbanization, weak governance, and the lack of disaster risk considerations in land management and environmental and natural resource management.


The conditions 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 (UNDRR, 2017). Vulnerability is the human dimension of disasters and is the result of the range of economic, social, cultural, institutional, political and psychological factors that shape people’s lives and the environment that they live in.


The occurrence of zoonoses – diseases naturally transmitted between animals and humans – is influenced by a range of factors. These include the climate, population expansion, agro-ecological changes and increases in the intensity of interactions between animals and people in both agricultural settings and the natural settings of wildlife. Recognising the frequent origins of human infectious diseases, and how they are transmitted to humans in the first place, One Health approaches consider interactions at the human-animal-environment interface as integral to positive health outcomes. 

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