Three prioritisation techniques
The techniques we will examine are:
As you will see, the techniques use different sets of criteria, and in different ways. Two of the models rank hazards/risks/ disasters individually on a numerical basis. The other model is a qualitative method to compare a number of hazards/risks/ disasters simultaneously. Keep these points in mind as you tackle the first reading, which covers the FEMA model and SMAUG prioritisation system. Each of these models for prioritisation were developed to prioritise hazards rather than risks, however the principles involved within each process can easily be adapted to prioritise risks.
The FEMA model and SMAUG prioritisation system
Read
Textbook: Natural Disasters Organisation 1992, Australian emergency manual - Community planning guide,Canberra, Annexes C and D of Chapter 4.
You will notice from the above reading that there is a basic difference between the FEMA model (developed by the US Federal Emergency Management Agency) and the SMAUG prioritisation system. In the FEMA model each hazard or in our case, risk, is rated individually using a number of quantitative parameters, such as history and probability, and individually given a numerical score based on the value of each of these parameters. The SMAUG system, on the other hand, directly compares hazards/ risks using a number of parameters, in a stepwise fashion, and is qualitative in its calculations.
What is the significance of this difference? The FEMA model, because it judges each hazard/ risk individually in a numerical manner, may provide more satisfying results than the SMAUG system if there are some good quality, numerical data on the hazards/ risks in question. The SMAUG system, on the other hand, allows close comparison of each hazard/ risk to the others in the given parameters, and therefore allows a closer examination of the difference between each hazard/ risk in a more holistic sense.
(The SMAUG system was developed by John Lunn & Bevis Dutton from a process taught by Kepner Tregoe.)
The Foster's index
There is a third prioritisation system, called the 'Foster's index '. This was developed by H.D. Foster in the 1970s, and is based upon the stress that may be caused to a given community by an emergency or disaster of a given magnitude. The method was developed in order to compare disasters that have occurred and takes into account the number of fatalities and injured, the amount of damage caused, and the total population affected. It is also possible to use Foster's method to compare the likely effects of hazards/ risks prior to an actual emergency by estimating numbers of fatalities and injuries, damage etc. from a given possible event. Foster's is thus similar to FEMA, in that each hazard, risk or disaster is rated on its own merits, as opposed to being compared to other hazards, risks or disasters in the SMAUG method.
Foster's index uses a formula and table to calculate the total stress caused by a disaster. The formula is:
|
TS |
= |
445a + 280b + cd |
where |
TS |
= |
total stress caused |
|
a |
= |
number of fatalities |
|
b |
= |
number of seriously injured |
|
c |
= |
infrastructure stress value |
|
d |
= |
total population affected |
(Note: this formula applies to disasters in the developed world. The formula for disasters in the developing world has the same form but with different numerical values.)
The infrastructural stress value is taken from the following table, and depends upon the magnitude of the effects of a disaster.
| Event Intensity | Designation | Characteristics | Stress Value |
I |
Very minor |
Instrumental. |
0 |
II |
Minor |
Noticed only by sensitive people. |
2 |
III |
Significant |
Noticed by most people including those indoors. |
5 |
IV |
Moderate |
Everyone fully aware of event. Some inconvenience experienced, including transportation delays. |
10 |
V |
Rather |
Widespread sorrow. Everyone greatly inconvenienced; normal routines disrupted. Minor damage to fittings and unstable objects. Some crop damage. |
17 |
VI |
Pronounced |
Many people disturbed and some frightened. Minor damage to old or poorly constructed buildings. Transportation halted completely. Extensive crop damage. |
25 |
VII |
Very pronounced |
Everyone disturbed; many frightened. Event remembered clearly for many years. Considerable damage to poorly built structures. Crops destroyed. High livestock losses. Most people suffer financial losses. |
65 |
VIII |
Destructive |
Many injured. Some panic. Numerous normal buildings severely damaged. Heavy loss of livestock. |
80 |
IX |
Very destructive |
Widespread initial disorganisation. Area evacuated or left by refugees. Fatalities common. Routeways blocked. Agriculture adversely affected for many years. |
100 |
X |
Disastrous |
Many fatalities. Masonry and frame structures collapse. Hazard-proofed buildings suffer considerable damage. Massive rebuilding necessary. |
145 |
XI |
Very disastrous |
Major international media coverage. Worldwide appeals for aid. Majority of population killed or injured. Wide range of buildings destroyed. Agriculture may never be re-established. |
180 |
XII |
Catastrophic |
Future textbook example. All facilities completely destroyed; often little sign of wreckage. Surface elevation may be altered. Site often abandoned. Rare survivors become life-long curiosities. |
200 |
Source: Foster, H.D. (1976). Assessing disaster magnitude: A social science approach, The Professional Geographer, 28 (3), 244.
It is obvious that Table 8.2 has been based on the Modified Mercalli scale as much as on the expected social stress of an event of a given magnitude. It is also obvious that not all of the characteristics mentioned in each of the possible event intensities are going to be applicable to all hazards, risks or disasters, or indeed to all communities, industries and activities. For example, how does one rate a human epidemic using this table? However, the relative effects of events can lead to a rough assignation of an intensity and thus a stress value. It is also obvious that Foster only intended his method to be used in relation to particularly harmful events-it is unlikely that it would be of much use for relatively minor events. Also, it is difficult to predict the number of deaths and injuries prior to an event, therefore this technique works best as a retrospective tool, and not a predictive tool.
If you are to use the Foster's index for prioritising hazards, a table of the following type may be of use in assisting to calculate the total stress values. Simply plug in the numbers for the various parameters to help you calculate the end total stress value.
| HAZARD | DEATHS (a) |
INJURIES (b) |
STRESS VALUE (c) |
POPULATION (d) | TOTAL STRESS (TS) |
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