Hazards: process, phenomenon and human activity

Learn about common hazards, the latest research on risk trends and solutions to reduce their impact.

Hazards are activity that may cause health impacts, property damage, social and economic disruption or environmental degradation.


With these links, you can learn about common hazards and explore their latest additions in the PreventionWeb Knowledge Base.

  • Avalanche
    Snow avalanche, snow slide, glacier avalanche.
  • Cold Wave
    Extreme weather/temperature, cold temperatures, cold spell, cold air outbreak.
  • Cyclone
    Hurricane, tropical storm, tropical cyclone, tropical depression, typhoon.
  • Drought
    Deficiency of precipitation, desertification, pronounced absence of rainfall.
  • Earthquake
    Earth tremor, seism, human-induced earthquake.
  • Epidemic and pandemic
    Epidemic: bubonic plague, cholera, dengue, non-pandemic diseases, typhoid; Pandemic: H1N1, HIV, smallpox, tuberculosis.
  • Flood
    Inundation, flash floods, Glacial Lake Outburst Flood, snowmelt flood, fluvial flood, surface water flooding.
  • Heatwave
    Extreme weather, extreme temperature, high temperatures.
  • Insect infestation
    Pest infestation, Invasion, swarm, outbreak, plague.
  • Landslide
    Mass movement, debris flow, mud flow, mudslide, rockfall, slide, lahar, rock slide and topple.
  • Nuclear, biological, chemical (NBC)
    Biohazard risk, chemical contamination, nuclear radiation risk, radioactive material, gas leaks.
  • Storm surge
    Seawater level rise during storms.
  • Technical disaster
    Explosions, collapses, urban fire, technical (dam, bridge) failure, rail accident, water supply failure, emergency telecommunications failure, outage, malware, ICT-related hazards.
  • Tornado
    Waterspout, land sprout, twister, vortex, whirlwind.
  • Tsunami
    A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake.
  • Volcano
    Lava, ash/tephra fall, molten materials, debris flow/lahars, pyroclastic flows, volcanic rock, volcanic gases.
  • Wildfire
    Bush fire, forest fire, peat fire, grass fire, uncontrolled fire, wildland fire.

Other hazards

PreventionWeb has collection pages on additional hazards, that are not part of the taxonomy, but where you can still find relevant content.

  • Sand and dust storms
    Sand and dust storms usually occur when strong winds lift large amounts of sand and dust from bare, dry soils into the atmosphere.
  • Fall armyworm
    The fall armyworm is an insect that can cause significant damage to crops, especially maize.

Related to this

People bringing sandbags to prevent flooding in Bangkok, Thailand (2011)
The role of hazards
Learn more about what hazards are and their role in PreventionWeb's Understanding Risk section.
Launch of the UNDRR/ISC Hazard Information Profiles: Supplement to UNDRR/ISC Hazard Definition & Classification Review: Technical Report (2020)
Hazard Information Profiles (HIPs)
A description of each of the 302 hazard information profiles (HIPs), developed using a consultative process by scientists and experts across the globe.

Learning from past disasters

Are you interested in how past disasters are informing DRR planning? Do you wish to find more information on notable disasters?

These collections explore the lessons learned from past disasters, what were the risk drivers, impacts and efforts towards building back better.

Image of a destroyed housing development.

Effective disaster risk reduction requires the consideration of not just what has occurred, but of what could occur. Most disasters that could happen have not yet happened.

UNDRR (2013)

Go further with PreventionWeb

Teacher read a book with a class of pre-school children
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.

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