A natural hazard is a natural process and event that is a threat to human life and property surrounding. The process and events that occur are not a hazard themselves, but they become a hazard because of human use of land. Severe weather and climate events, floods, and wildfires are all examples of natural hazards.

A disaster is a hazardous event that occurs over a short time span and happens within a defined area. A disaster is different from a natural hazard because for an event to be considered a disaster it has to meet a certain criteria. A disaster has to kill 10 or more people, 100 or more are affected by the event, emergency state is declared, and international assistance is requested. If any of these four occur, it is then considered a disaster. A disaster can be floods, tsunamis, volcanic eruptions and earthquakes. An example is the Indian Ocean earthquake and Tsunami that occurred in 2004.

A catastrophe is an event that causes great damage, requires a lot of money, and a long time to recover. It is bigger than a natural hazard and a disaster. A catastrophe affects the life of millions of people around the world. An example is Hurricane Katrina in 2005, happened 10 years ago and recovery still continues in some parts of New Orleans.