Section 1: Introduction — Disasters and Disaster Management

Scenario: A train has just derailed in your community. At least one of the train cars has exploded and emergency responders are on their way to the scene of the disaster.

In this section, we will explore how an incident, like a train derailment, can escalate into a disaster situation.

Close-up of the wheels of a train engine that has left the rails

How Events Become Disasters

Hazards, incidents, accidents, catastrophes... There are many terms in the lexicon of disaster management. At the end of this course, we provide some recognized glossaries of disaster terminology from government agencies and research centers. For the purposes of this course, it is important for us to define what we mean when we talk about a "disaster."

We can consider disasters to be part of a chain of escalating incidents, starting with hazards and becoming more serious in the scope of the population impacted and the scale of response required. To help illustrate this chain of escalating incidents, we will use the example of a train accident. Click the left and right arrows to scroll through the scenario below.


Disasters Defined

Disaster: 1. A serious disruption of the functioning of a community or a society causing widespread human, material, economic or environmental losses which exceed the ability of the affected community or society to cope using its own resources (ISDR). 2. Situation or event, which overwhelms local capacity, necessitating a request to national or international level for external assistance (CRED).


World Health Organization:

The definition captures the clear distinction between a disaster and an emergency or an event. Disasters disrupt the functioning of society. They cause widespread losses that exceed the capacity of the affected society to cope using its own resources.

Disaster Types

Under the broad category of "disaster," there are many different types, including:

  • Bioterrorism
  • Chemical emergencies
  • Fires and wildfires
  • Geological hazards
  • Radiation emergencies
  • Weather and storms
  • Public health emergencies including infectious diseases: pandemic, epidemic and disaster-related outbreaks

Public Health Emergencies

The Secretary of the Department of Health and Human Services (HHS) may, under section 319 of the Public Health Service (PHS) Act, determine that: a) a disease or disorder presents a public health emergency (PHE); or b) that a public health emergency, including significant outbreaks of infectious disease or bioterrorist attacks, otherwise exists (view source). The PHS Act continues to be updated and amended. In March 2013 Congress passed and the President signed the Pandemic and All-Hazards Preparedness Reauthorization Act (PAHPRA).

This list shows the variety of disasters that can cause great damage, destruction, and human suffering. Disasters can be caused by naturally occurring events like severe weather and storms, or man-made acts of terrorism, or accidental chemical or radiation emergencies.





While it is important to consider specific disaster types when providing disaster information services, an important concept in managing disasters and emergencies is "All-Hazards." A common set of activities, such as protecting lives and minimizing disruptions to societies, applies to all hazards, whether they are natural or man-made.

All-Hazards: Describing an incident, natural or man-made, that warrants action to protect life, property, environment, and public health or safety, and to minimize disruptions to government, social, or economic activities.


All-Hazards definition from:

For the purposes of the course, we will be talking generally about all-hazards when we speak of disasters, unless we name a particular disaster type.

Four illustrations; the first is a triangle enclosing an explosion; the second is a funnel representing a tornado; third is an errupting volcano; last is a house and car covered in flood waters


Disaster and Emergency Management

All-hazards disaster and emergency management can be understood as a three-phase model of preparedness, response, and recovery activities. These three phases are part of an ongoing cycle. When we are not responding to or recovering from disasters, we are planning for future events and emergencies.

Circle diagram of the disaster management cycle, with three shaded areas representing the three phases. The preparedness phase is the longest and covers from about the 12:00 position to just past the 8:00 position. The response phase is the shortest, and is from about the 8:30 position until the 9:00 position. Finally, the recovery phase represents from about the 9:00 position to the 12:00 position, completing the cycle.


As the response phase is typically the most high profile in any disaster, there is a common misconception that all disaster and emergency management activities occur during this phase. But it is during the longer preparedness and recovery phases in disaster management that a wide variety of activities also occur. For example, emergency responder training, disaster research, and community outreach are most likely to happen during the preparedness phase. Activities such as the organization of donations, data collection on displaced individuals, and allocation of assistance resources occur during the response as well as the recovery phase.

Disaster information specialists are needed during all disaster and emergency management phases, but it is during the preparedness and recovery phases where their skills finding, assessing, and disseminating critical disaster health information are most likely to be utilized.


Key Points

In this section, we covered the following main points:

  • Disaster and emergency management is a cycle of ongoing activities.
  • Disaster health information is needed during all phases.