FDI's

[misterteddy]

So for me the question is, what is the FDI for?

Short answer is to have some sort of quantifying system so as to be able to describe
an expected level of fire behaviour simply, without having to detail the science and
data used to calculate it.  GFDI & FFDI numbers mean something to people in the
business of managing & fighting fires.

As Mr.Teddy also quite rightly points out, as fuel loads vary wildly across a district,
the actual FDI in specific locations also varies wildly.  An over-grazed paddock will have a far lower FDI than the standing wheat crop or the scrub either side of it.  FDI
numbers are meaningful at specific locations, not so meaningful across whole districts
unless they are all very big or very small.

So different organisations use FDIs to nominate risk levels & trigger points relevant
to them.

For example, ETSA set 3 levels of risk regarding their infrastructure - see
http://sacfs.org/publications/Operations_Management_Guidelines_Third_Edition_Nov2004.pdf page 77

Most fire services use 5 descriptive levels of fire behaviour & risk for general public
consumption.  Loosely describe the likelihood of an ignition escaping out of control. Low (0-20), moderate(20-30), high(30-40), v.high(40-50) & extreme(>50).  The system is
stating that fire fighters are very unlikely to be able to control any fire when the
FDI is greater than 50.  Sometimes we get lucky.  Sometimes we don't.

As with any gross simplification, it has short-comings. The cut-offs between each level are arbitrary.  As Mr Teddy quite rightly points out, there is sod-all difference in
fire behaviour between FDI of 49 & 50, but one is oficially "Very High", the other
is "Extreme".

But we need to have a quantifiable trigger-point, above which certain behaviours are demanded of the public, and penalties can be enforced for non-compliance.

Al, absolutely agree all, great executive summary

[Alan J]

Thankyou Mr.T

For my part I have re-thunk Reply #32.
It is probably better not to mention FDIs to the Great Unwashed.
Would only confuse them with data. [1]

Further, I think that most of the public think that the 5 Level "Fire Danger"
scale means "probability of a fire occurring".  That's how it comes across on
the nightly weather forecast & other media.  I think that is an unhelpful
interpretation. The more "very high" or "extreme" days occur without a fire
occurring -to them-, the more complacent people become.

From what I have read, "Fire Danger" was a term chosen 50 or more years ago.
Its users & target audience were people who mostly also knew it referred to fire
behaviour rather than probability of fire occurring.

I think the target audience has changed in half a century, and therefore its
name needs to change.

I have a gut feeling that if we were to re-educate the public that low/moderate/
high/etc describes likely "Fire Behaviour" or "Fire Escape Risk", it would
improve the way many people think & go about their fire season preparations.

Does this match other peoples' observations?


[1] don't know who coined this expression:
"Data isn't information.  Information isn't knowledge.  Knowledge isn't wisdom."

But I like it.