Assessing the Risk

By Barry Bouwsema

The past decade has brought the issue of disasters to the forefront with numerous unfortunate events occurring. Following any major disaster, the topic of disaster preparedness becomes a topic of discussion and/or debate. The process of disaster planning follows an established procedure to ensure preparedness.

Preparing for a disaster begins with a comprehensive risk analysis. This analysis provides planners with information about the types of emergencies that may occur and the potential consequences. Following an in-depth analysis, planners are able to determine what steps will be necessary to prevent the possible hazard and how to respond if an incident occurs.

The five steps to risk analysis include:

  1. Identify the hazard: the kinds of emergencies that have occurred or can occur in your jurisdiction.
  2. Profile the hazard and the potential consequences: review historical and predictive information on each hazard, and estimate the potential impact for your community.
  3. Compare the risks: through qualitative and quantitative analysis, determine the relative threat posed by the individual hazards; then, decide which hazards warrant special attention in the planning process.
  4. Create a disaster response: develop a planned response for the hazards identified (those that exceed the established threshold).
  5. Test the plan through table top exercises, functional exercises, or live disaster drills.

Risk analysis begins by identifying and listing the possible hazards present in your community or at your event. Identifying the hazards must also include considering the possibility of a second hazard, for example the loss of power or wide spread fires following a hurricane. A typical risk analysis will include such items as: avalanche, bomb threat , drought , earthquake, epidemic, fire, flood, hazardous material spill, hurricane, landslide, loss of utilities, structural collapse, terrorist activity, tornados, weapons of mass destruction, wildfires; and the list goes on and on. Any event or situation in your community that would have a major impact, if a disaster occurred, should be considered and included in the risk analysis. (FEMA, 2000, pg. 14 – 16).

After creating a list of possible risks, the characteristics of each hazard must be profiled to determine the consequences of the risk. Characteristics to identify include:

  • Frequency of occurrence: both historical and predicted;
  • Magnitude and intensity: the projected severity of the hazards occurrence;
  • Location: especially if the hazard is associated with a specific facility;
  • Duration: the length of time the hazard is expected to last;
  • Spatial extent: the geographical area expected to suffer the impact of the hazard;
  • Seasonal pattern: the time of the year that the hazard threat exists; and
  • Availability of warning and speed of onset: the amount of time projected between the first warning and the actual occurrence of the hazard.

It may not be possible to address every possible hazard that has been identified as the list could be extremely lengthy. Therefore, it is necessary to rank the possible hazards according to likelihood (extremely unlikely to highly likely) and impact (negligible to disastrous). Event impact, community impact, and participant impact are each rated on the impact risk score of one to 1000, and then added together to give a total impact numerical value. The total impact score is then multiplied by the likelihood of the event, ranging in value from one to 20; this will give a final value or total risk score (see Table 1). By this method, the most significant hazard or threat can be dealt with in order of priority. The total risk score is then applied to a quantitative assessment of residual risk (see Table 2). The risk is then determined to be negligible, acceptable, marginally acceptable, undesirable, or intolerable. The established level of acceptability will determine if a disaster response procedure will be developed for the specific hazard. This is one of several models available for assessing risk.

Table 1 – Inherent Risk Score

Impact Negligible – 1 Marginal – 5 Moderate – 10 Substantial – 50 Severe – 100 Disastrous – 1000
Likelihood Extremely Unlikely – 1 Very Unlikely – 2 Unlikely – 5 Somewhat Likely – 10 Likely – 15 Highly Likely – 20
Event Impact Community Impact Participant Impact Total Impact Likelihood Total Risk Score

Step 1: Event Impact + Community Impact + Participant Impact = Total Impact
Step 2: Total Impact x Likelihood = Total Risk Score
Step 3: Apply the total risk score to the quantitative assessment of residual risk to determine a
response category

Table 2 – Quantitative Assessment of Residual Risk

Response Category Negligible

Less than 10

10 – 49
Marginally Acceptable

50 – 499

500 – 1999

Over 1999

Creating a disaster plan is a response to quantitative assessment of residual risk. Identified hazards that are likely and have a significant impact must be addressed in the disaster plan. By having an established strategy for the mitigation of the hazard, if it occurs, a preferred outcome will hopefully be achieved. Emergency planning must be viewed as a process rather than an end product. The process of planning involves the sharing of information, educating stakeholders, addressing concerns, and refining the communication process. Disaster preparedness planning is most effective when it is viewed as a continuous process.

For the identified high risk situations, scenarios that work through the hazard and the expected response should be developed. Table top exercises and mock disasters take the proposed plan off the shelf and give it the opportunity of application. The performance of the plan and the responders can thereby be tested and evaluated. Any areas identified that require clarification or modification can be addressed. Testing the plan through an exercise validates the document. Perhaps the greatest value of an exercise is having the different agencies operating together prior to a real emergency situation.

Preparing for the disaster that could happen within your jurisdiction begins with a comprehensive risk analysis and ends with practicing the plan. Being prepared for the worst allows planners to have responders and needed supplies on hand if and when a disaster occurs.

Reference: FEMA. 2000. Special Events Contingency Planning Manual.

Barry Bouwsema is a company officer for Strathcona County Emergency Services, Sherwood Park, Alberta. He has been in the fire service for 20 years, and is a graduate of Athabasca University with a bachelor’s degree in General Studies. Bouswema lectures paramedic students at the Northern Alberta Institute of Technology and teaches firefighters (NFPA 1001) at the Emergency Services Academy.

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