Primarily disasters are triggered by natural hazards or human-induced, or result from a combination of both.
In particular, human-induced factors can greatly aggravate the adverse impacts of a natural disaster.
The widely accepted classification system used by the Disaster Information Management System of DesInventar classifies disasters arising from natural hazards into five major categories
1.GEOPHYSICAL : Geological process or phenomenon
#Earthquake/Mass movement of earth materials :
2. Hydrological : Events caused by deviations in the normal water cycle and/or overflow of
bodies of water caused by wind set-up
3. Meteorological : Events caused by short-lived/small to meso-scale atmospheric processes (in
the spectrum from minutes to days)
Eg : Cyclone, Storm Surge, Tornado, Convective Storm, Extratropical Storm, Wind, Cold Wave, Derecho, Extreme Temperature, Fog, Frost, Freeze, Hail, Heat-wave, Lightning, Heavy Rain, Sand-Storm, Dust-Storm, Snow, Ice, Winter Storm, Blizzard
4. Climatological : Unusual, extreme weather conditions related to long-lived, meso- to macro-scale atmospheric processes ranging from intra-seasonal to multi-decadal (long-term) climate Variability
Eg : Drought, Extreme hot/cold conditions, Forest/Wildfire Fires, Glacial Lake Outburst Subsidence
5. Biological : Exposure to germs and toxic substances
Eg : Epidemics: viral, bacterial, parasitic, fungal, or prion infections
HUMAN INDUCED DISASTERS
The NPDM notes that rise in population, rapid urbanization and industrialization, development within high-risk zones, environmental degradation, and climate change aggravates the vulnerabilities to various kinds of disasters.
Due to inadequate disaster preparedness, communities, and animals are at increased risk from many kinds of human-induced hazards arising from accidents (industrial,road, air, rail, on river or sea, building collapse, fires, mine flooding, oil spills, etc.).
Terrorist activities and secondary incidents add to these risks and call for adequate preparedness and planning.