Lessons from the Ashes
In regard to fire behavior, spotting ahead of the main fire front played a significant part in the forward rate of spread and the development of all the fires. Evidence was found of some spotting reaching more than 20 kilometers from the main fire. In addition, the current fire behavior meters underpredicted the forward rate of fire spread seen on the day.
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As for human behavior, there were many examples of weak links in people's planning and preparation that affected their ability to implement their household fire plan. Despite the efforts of agencies and politicians in the days before the fires, many residents were not prepared for the severity of the Feb. 7 bushfires. A considerable amount of last-minute planning and preparation took place on the day.
Prior to the fires, 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 Feb. 7 was to be a day of unprecedented fire danger. There was only modest awareness of the implications of this within the community.
The difference between intentions and actions was studied as well. For example, 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 they were not fully committed or confident in their ability to do so in all conditions.
In fact, fewer than half of the households in the initial sample reported that a household member stayed to defend a property. Some of those who intended to stay and defend a property 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.
The research uncovered several emerging issues and themes:
Many community members regard public buildings, sports grounds and emergency services facilities as safe places of refuge during a bushfire.
Some of those who stayed to defend their properties reported a range of factors that influenced their capacity to defend their homes, including heat exhaustion, dehydration, breathing difficulties and eye irritation. A range of pre-existing medical conditions, such as asthma and arthritis, also inhibited some people.
Anecdotal evidence suggests that many of those who sheltered passively inside their homes may have done so in bathrooms.
The examination of building planning and land-use factors revealed that active defense of structures has a major influence on house survival. In addition, building quality, detail and possibly house age appear to determine the likelihood of house loss. For example, brick houses performed significantly better than mud brick and lightweight construction clad with timber or cellulose cement sheet. The potential for wind damage of structures should be a key factor in future building standards for bushfire-prone areas as well.
Water supply factors also were examined. Metal and concrete water tanks were found to be more effective in maintaining an effective water supply for house defense than polyethylene or fiberglass tanks. Careful design of piping and pump location are required to maximize the chance of maintaining an effective water supply throughout the fire event. Of course, main water pressure and household electricity cannot be relied on.
Finally, vegetation overhanging or immediately adjacent to a house is a key factor in house loss, but house loss has occurred at distances greater than 380 meters from continuous bush.
The task force data have not been the only information collected since February; considerable supplementary data have the capacity to deepen and strengthen the current analysis.
Due to the time frames involved, the task force did not consider the observational logs of fire service personnel or material collected by other agencies, such as police fatality information, the rapid-impact assessment facilitated by the Victorian Office of the Emergency Services Commissioner on behalf of the response agencies or the detailed post-event weather reports by Australia's Bureau of Meteorology. There also is a wealth of information available at various media and public Web sites that provide first-hand reports, video and photographs of fire behavior and effects across multiple locations that can be used in future work.
The foresight of the leaders of the Victorian agencies in initiating the work to date has ensured that vital data from this event were captured. Although it is hoped that this data will help us better understand such events in the future, there currently is no arrangement for a more complete analysis of the data or for the consolidation of this data with that collected by other agencies.
The task now is to consider what further work is required to gather what has been learned and ensure that future policy considerations are based on a comprehensive analysis of recent events. The lessons of a fire of this scale are crucial for all those charged with the responsibility of protecting communities, maintaining the land and allocating resources.
Gary Morgan is the Chief Executive Officer of the Bushfire Cooperative Research Centre and is on the Board of Directors of the International Association of Wildland Fire.
More details can be found in the Executive Summary of the Interim Report of the Victorian Bushfires 2009 Research Taskforce at www.bushfirecrc.com.
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