Disaster, Definition of

Disasters are caused by hazards (natural, human-made, or some combination of both) when they intersect with a vulnerable population, causing severe damage or destruction to people, resources, and the surrounding environment. To prepare for and respond to disasters, crisis management must identify potential threats to a group, which includes both considering the hazard that will prompt the disaster and the population it will affect—a wide range of factors. In addition to physical effects such as human deaths and injuries, and damage or destruction of human-made and natural landscapes, disasters may directly or indirectly impact social and political structures, causing economic problems and environmental destruction and loss of life.

Despite these general characteristics, many people and organizations offer various specific definitions of disasters. People often casually use the term disaster interchangeably with related terms like catastrophe, crisis, or emergency. Defining disasters is complicated by the wide range of events that can fall under the term that can be framed by their causes (such as natural hazards) and their effects (widespread devastation, large numbers of a population killed or left homeless).

The disaster itself is often considered to cover a set period of time marked by when a natural hazard's direct effects began and ended or between a human-made hazard's release and cleanup. However, the effects of a disaster and the recovery period after it can last beyond that time, concluding long after the disaster itself is considered to have ended. Moreover, social circumstances and [Page 265]human changes to the environment that can affect a disaster predate the direct effects of the hazard on a population. A disaster is not solely the product of the hazard involved but also emerges from the affected population.

Homes in Henryville, Indiana, lay shattered five days after a series of tornadoes struck southern Indiana on March 2, 2012. Thirteen people died and hundreds were left homeless. President Barack Obama issued a major disaster declaration on March 9, two days after joint preliminary damage assessments were completed in six counties. By definition, a natural disaster is considered to cover a set period of time marked by when the hazard's direct effects begin and end, but the effects of a disaster and the recovery can last far beyond that.