By Dr Richard Thornton, Research
Director, Bushfire CRC
The Victorian bushfires of 7 February 2009
resulted in major loss of life, property, and other assets. The
questions and issues that quickly emerged will be the subject of
debate, in Australia and internationally, for years to
come.
In
developing directions for the future, the Victorian fire and
land management agencies believed it was vital that decisions
were based on solid evidence of what happened and why. To do
this thoroughly, a major research effort was required to
establish an authoritative and independent set of data for the
Australian and international fire community.
Less than 48 hours after the devastating
bushfires, the Bushfire CRC was asked to establish a Research Taskforce to undertake
the biggest data collection and analysis program ever undertaken in
the aftermath of a bushfire disaster in Australia, and quite
probably anywhere.
Almost every day over a period of nearly two and
half months, the Bushfire CRC placed teams of up to 50 researchers
from across Australia, New Zealand and the United States in the
field. This amounted to more than 2000 staff days of extensive data
collection and analysis, working in the aftermath of the disaster
alongside fire fighters, police, community workers and residents
across the fire affected areas.
The Taskforce looked at more than 1300 homes,
interviewed more than 600 residents, and took over 21,000
photographs.
This was not the only data collected in this
period and much of this supplementary data will have information
that could add further depth to the analysis. Specifically, this
Taskforce has not considered observational logs of fire service
personnel or material collected by other agencies (most notably
police fatality information and the Rapid Impact Assessment
facilitated by the Office of the Emergency Services Commissioner on
behalf of the response agencies) or the detailed (post-event)
weather reports of by the Bureau of Meteorology.
There is also a wealth of information available
on various web pages, both on media and public sites, that provide
first-hand reports and visual images (video and photographs) of
fire behaviour and impacts across a variety of locations that can
be interrogated in future work.
The imperative for the Research Taskforce was to
collect time-critical data that would rapidly degrade due to the
weather, site clearance or other types of interference.
This data addresses a range of questions
relating to fire behaviour, human behaviour, and house survival or
destruction.
In broad terms, the research focussed on:
-
the fire behaviour observations across the
major Victorian fires
-
the human behavioural factors that impacted
upon the patterns of property or life loss or saves during these
fires
-
the building and land-use planning factors in
select areas that contributed to the pattern of property or life
loss (or saves) during these fires
-
the way in which these factors worked
collectively to impact on the pattern of loss of life and
property.
All aspects of the work considered the question: Was
the impact of the fires of 7 February 2009 consistent with
established knowledge or was this a result of previously
unidentified behaviours or factors?
An interim report was submitted to
the 2009 the Victorian Agencies and subsequently the Victorian
Bushfires Royal Commission in June. This report of around 700 pages
outlines the data collected across various areas that were burnt,
as well as drawing some preliminary conclusions and findings from
this data.
Some of these preliminary findings related to
specific fires, others were more general across all the fires. Some
of the more general findings include:
Fire behaviour
-
Spotting ahead of the main fire front played a
significant part in the forward rate of spread of all the fires.
Evidence was found of some spotting reaching more than 30kms from
the main fire.
-
The current fire behaviour meters
under-predicted the forward rate of fire spread seen on the
day.
-
The 1939 Black Friday fires provide the
closest set of conditions for comparison with 7 February 2009.
(Those fires burnt almost 2 million hectares with the loss of 71
lives.
Human Behaviour
Planning and preparedness:
-
Many residents were not prepared for the
severity of the 7 February bushfires.
-
A considerable amount of last-minute planning
and preparation took place on the day.
-
There are many examples of ‘weak
links’ in people’s planning and preparation that
affected their ability to implement their fire plan.
Information and Warnings:
-
Fire agencies and local councils had been only
modestly successful in informing members of at-risk communities
about effective preparation and planning for bushfires.
-
Predictions in the preceding week were that
Saturday 7 February was to be a day of unprecedented fire danger.
There was only modest awareness of the implications of this within
the community.
Intentions and
actions:
-
A significant number
of residents intended to wait and see what the bushfires were like
before deciding whether to stay or go. These residents wanted to
stay and defend their homes and properties, but were not fully
committed or confident in their ability to do so in all
conditions.
-
Less than half of the
households in the initial sample reported that a household member
stayed to defend. Some of those who intended to stay and defend
left because of the severe conditions.
-
More than half of the
households in the initial sample reported that a household member
left because of the fires. There appear to have been many late
evacuations.
-
A very small number
of interviewees took no defensive action and sheltered throughout
the fire.
Emerging issues and themes:
- Many community members regard
public buildings, ovals and emergency services facilities as safe
places of refuge during a bushfire.
- Some of those who stayed to defend
their homes and properties reported a range of factors that
influenced their capacity to defend their homes. These included
heat exhaustion, dehydration, breathing difficulties, and eye
irritation. A range of pre-existing medical conditions, such as
asthma and arthritis, also inhibited some people’s capacities
to defend their homes.
- Anecdotal evidence suggests that
many of those who sheltered passively inside their homes may have
done so in bathrooms.
Building and
Planning
-
Active defence of structures has a
major influence on house survival.
-
Building quality, detail and
possibly house age appear to be factors in determining the
likelihood of house loss.
-
Brick houses performed
significantly better than mud brick and light-weight construction
clad with timber or cellulose cement sheet.
-
The potential for wind damage of
structures should be a key factor in future building standards
consideration for bushfire-prone areas.
-
House loss has occurred at
distances greater than 380m from continuous bush.
-
Metal and concrete water tanks are
more effective in maintaining an effective water supply for house
defence than polyethylene or fibreglass tanks.
-
Careful design of piping and pump
location are required to maximise the chance of maintaining an
effective water supply throughout to fire event.
-
Mains water pressure and mains
electricity cannot be relied upon during a fire event.
-
Vegetation overhanging or
immediately adjacent to a house is a key factor in house
loss.
It
was due to the foresight of the leaders of the Victorian
agencies in initiating this work that have ensured the
learnings from this event were captured in the hope that this
will help us all better understand such events into the
future.
The next stage is to undertake a thorough
scientific analysis of the data. This requires agreement on the
research questions for which knowledge is sought and on
stakeholders who wish to be involved.
The Bushfire CRC is actively
encouraging international collaborations to increase the research
effort and to share the new knowledge globally.
More details on the 2009 Research Taskforce can
be found here.
(This article first appeared in
the Spring 2009 issue of Fire Australia magazine.)