Topic 5: Hazard description
Overview
This topic continues on from the identification of hazards in Topic 4 and examines how we describe the hazards that we have chosen for full analysis. When we describe hazards, we consider all of the features of the hazards that may have a bearing on emergency management. However, one thing that is not described is the effects or consequences of a hazard, as this requires an understanding of the community and environment.
If you read the section 'Identify risks' in the Emergency Risk Management Applications Guide (EMA, 2000, pp 10 - 15) you will see that we not only have to identify and describe the hazards, but we also have to comprehensively describe the community and environment and from those descriptions scope the community's and environmental vulnerability before we can identify the risks.
OK, on with our discussion relating to hazard description. As an example of a hazard, we will take flood to illustrate the ways in which hazards can be described. In doing so we will identify some key characteristics which can serve as principles for hazard description. We then look at other hazards to see if the characteristics typified by flood are equally appropriate.
The data to describe hazards can be used to construct what are known as hazard or risk maps. As you will see in a later section dealing with hazard and risk mapping , these maps can be used to display information graphically in ways that are of great value and use to emergency managers.
Finally, we overview briefly the use of geographic information systems (GIS) or spatial information systems (SIS)-computer-based programs that can greatly facilitate the collation and analysis of data for use in hazard and risk mapping.
Learning outcomes
After completing the work for this topic, you should be able to:
- list some characteristics that may be used to describe hazards;
- explain what these characteristics mean, and give examples of their use;
- describe a hazard using these characteristics;
- describe the value of hazard and risk mapping to risk assessment.