Natural

Climatic

cyclone
desertification
drought
fire – brush, forest, wild
floods
heat
hurricanes
ice / snow
tornadoes
typhoons
winds

Geophysical

avalanche
debris flows
earthquakes
landslides
liquefaction
rock falls
tsunamis
volcanoes

Biological

epidemics
pest infestation
animals (rodents, birds)

Human Made

Technological

chemical / hazardous material deforestation
environmental pollution
industrial fires
nuclear accident
power failure
transportation accident

Human Fault

chemical / hazardous material
environmental pollution
industrial fires
nuclear accident
power failure
transportation accident

Hostile Action

chemical / hazardous material
civil disobedience
industrial fires
nuclear accident
power failure
transportation accident
war