44th Annual Meeting – General Session, May 15, “When disaster mitigation is a priority: Evidence from risk analysis of rare events” by Irene Karsten and Stefan Michalski

In this talk, Irene Karsten presented a method that CCI has established to quantitatively evaluate risk assessment for an institution. CCI has been using this method, called the ABC method, to conduct risk assessment for heritage institutions. The probability of a certain incident is estimated by answering the following questions:

  1. How often will the event occur?
  2. How much value will be lost?
  3. How much of the heritage asset will be affected?

A score of 5 points is generated for A, B, and C, for a total magnitude risk out of 15 points. A total of 5 points or lower is considered negligible risk and 15 points is catastrophic and unacceptable.

Score Risk Loss to collection
5 or lower Negligible  
9 or lower Medium to negligible Damage takes millennia. May agree that level of care is adequate and improvements possible but wait till higher risks are reduced.
10-11 Medium – high Maybe negotiable. Standard of care may be okay but improvements highly recommended
12-13 High Lost in 100 years, may be unacceptable
15 Catastrophic Unacceptable. All value lost in decades. Such risks are rare.

In this talk, Karsten is paying particularly attention to level 10-13 risks. Also, this is a logarithmic scale, which allows the authors to graph a lot of risks on each graph and compare them easily. Karsten went through a number of examples, including two historic houses, art gallery, provincial archives, and science and technology museum, highlighting the various risks and how they were evaluated. For all five institutions, disaster risks in high or extreme categories were fire. CCI did not just assess the risks, but also looked at mitigation of risk. For fire, CCI recommends an automatic fire suppression system. This does not eliminate fire risk but substantially reduces the risk of spread. In terms of cost-effectiveness, options that reduce large risks tend to have a better cost-effectiveness, too. When assessing if your collection is at a serious risk of loss, it has to impact storage.
Karsten then went through five types of weather disasters and explained how an institution would be assessed to be at an extreme or high risk for that threat.
For a flood, an institution is at extreme risk if storage is below flood grade or even below grade near the old water main or faulty storm sewers. An institution is at high risk if it is on grade on a flood plain or below grade.
For a fire, an institution is at extreme or high risk if it is a combustible building structure, there is lack of compartmentation, the region is at risk of wild fire, or there is a lack of automatic fire suppression. 1 in 5 fires is expected to spread to the whole structure.
For an earthquake, an institution is at extreme risk if the building is lacking seismic protection and there is a risk of violent earthquakes (7 or higher on the Richter scale). An institution is at high risk if storage is lacking seismic protection and there is a risk of very strong to violent earthquakes (6.5 or higher on the Richter scale).
For a tornado, an extreme risk is EF4 or EF5 tornados in US and high risk of EF4-5 in Canada, depending on the frequency of tornados in the area.
For a hurricane, an extreme risk is if the building is in a region at risk of major hurricanes (category 3-5) and the building is not designed to resist high winds. In Canada, only category 2 hurricanes really occur, and the damage is rarely extensive to be high or extreme risk.