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 (UNISDR, 2016).
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.
Avalanche, Cold Wave, Cyclone,Drought, Earthquake,Epidemic & Pandemic, Flood, Heat Wave, Insect Infestation, Land Slide, NBC - Nuclear, Biological, Chemical, Storm Surge, Technical Disaster, Tornado, Tsunami, Volcano, Wild Fire.
Natural hazard events can be characterized by their magnitude or intensity, speed of onset, duration, and the area they cover.
Essential steps in hazard assessment are identifying the relevant hazard(s) and the collection of hazard-related data. Once the hazards are defined, the next step often involves obtaining a variety of hazard-related data. The most essential data define the date, geographical location and extent, and maximum intensity of historical events.
The adverse impacts of hazards, in particular natural hazards, often cannot be prevented fully, but their scale or severity can be substantially lessened by various strategies and actions.
Risk is a forward looking concept, so disaster risk can be understood as the likelihood (or probability) of loss of life, injury or destruction and damage from a disaster in a given period of time (adapted from UNISDR, 2015a).
A dangerous event that may cause loss of life, injury or other health impacts, as well as damage and loss to property, infrastructure, livelihoods and services, social and economic disruption and, or environmental damage is known as a hazard (UNISDR, 2009b).
The presence and number of people, property, livelihoods, systems or other elements in hazard areas (and so thereby subject to potential losses) is known as exposure (UNISDR, 2009b and IPCC, 2012).
The name given to the set of characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard is vulnerability.
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 is both a driver and consequence of disasters, reducing the capacity of the environment to meet social and ecological needs.
Globalized economic development can lead to increased exposure of assets in hazard-prone areas, leading to further increases in intensive risk if not managed.
Poverty is both a driver and consequence of disasters, and the processes that further disaster risk related poverty are permeated with inequality.
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.
Capacity refers to all the strengths, attributes and resources available within a community, organization or society that can be used to achieve agreed goals.
Deterministic risk considers the impact of a single risk scenario, whereas probabilistic risk considers all possible scenarios, their likelihood and associated impacts.
Direct disaster losses refer to the number of people killed and the damage to buildings, infrastructure and natural resources. Indirect disaster losses include declines in output or revenue and generally arise from disruptions to the flow of goods and services.
DRR is the policy objective of anticipating and reducing risk. Although often used interchangeably with DRR, DRM can be thought of as DRR implementation, since it describes the actions that aim to achieve the objective of reducing risk.
Extensive risk is used to describe the risk of low-severity, high-frequency disasters, mainly but not exclusively associated with highly localized hazards. Intensive risk is used to describe the risk of high-severity, mid to low-frequency disasters, mainly associated with major hazards.
Resilience refers to the ability of a system, community or society exposed to hazards to resist, absorb, accommodate to and recover from the effects of a hazard in a timely and efficient manner.