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.
Disaster risk is widely recognized as the consequence of the interaction between a hazard and the characteristics that make people and places vulnerable and exposed.
What is disaster risk
Disasters are sometimes considered external shocks, but disaster risk results from the complex interaction between development processes that generate conditions of exposure, vulnerability and hazard. Disaster risk is therefore considered as the combination of the severity and frequency of a hazard, the numbers of people and assets exposed to the hazard, and their vulnerability to damage (UNISDR, 2015a). Intensive risk is disaster risk associated with low-probability, high-impact events, whereas extensive risk is associated with high-probability, low-impact events.
There is no such thing as a natural disaster, but disasters often follow natural hazards.
The losses and impacts that characterise disasters usually have much to do with the exposure and vulnerability of people and places as they do with the severity of the hazard event (UNISDR, 2013).
Disaster risk has many characteristics. In order to understand disaster risk, it is essential to understand that it is:
- Forward looking the likelihood of loss of life, destruction and damage in a given period of time
- Dynamic: it can increase or decrease according to our ability to reduce vulnerability
- Invisible: it is comprised of not only the threat of high-impact events, but also the frequent, low-impact events that are often hidden
- Unevenly distributed around the earth: hazards affect different areas, but the pattern of disaster risk reflects the social construction of exposure and vulnerability in different countries
- Emergent and complex: many processes, including climate change and globalized economic development, are creating new, interconnected risks
Disasters threaten development, just as development creates disaster risk.
The key to understanding disaster risk is by recognizing that disasters are an indicator of development failures, meaning that disaster risk is a measure of the sustainability of development. Hazard, vulnerability and exposure are influenced by a number of risk drivers, including poverty and inequality, badly planned and managed urban and regional development, climate change and environmental degradation (UNISDR, 2009a, 2011, 2013 and 2015a).
Understanding disaster risk requires us to not only consider the hazard, our exposure and vulnerability but also society's capacity to protect itself from disasters. The ability of communities, societies and systems to resist, absorb, accommodate, recover from disasters, whilst at the same time improve wellbeing, is known as resilience.