Bryce Touchstone
GR8813 Advanced Hazards and Disasters
Mississippi State University; Fall 2011
Emergency Management Methods for Bushfires in Western Australia
Outside of Antarctica, Australia is the driest continent on earth(BOM, 2011). While it is comparable in size to the contiguous United States, it is geographically disadvantaged when it comes to rainfall in a couple of regards: It lacks a major mountain range, and its continental poleward extent is well outside of the Antarctic, which provides little rainfall from orographic effects and quarantines the country from polar air outbreaks, as compared to the United States. Australia relies heavily upon Tropical influences for rainfall in the North, and upon river systems to bring water down to the drier Southern regions.
Fire itself is controlled by the fire triangle of heat, oxygen, and fuel, while the fire environment is controlled by the fire behaviour triangle which consists of weather, topography, and fuels(COMET, 2009). The elements of weather that affect fire behaviour are temperature, relative humidity, wind speed and direction, precipitation, and atmospheric stability(COMET, 2009). Bushfires thrive under hot, dry, windy conditions, with natural ignitions of fuel coming often from lightning. Under a regime of a stalled ridge with surface conditions hot and with relatively high pressure in place, particularly in summer months, bushfires can last for weeks. In the Australian Outback region, oftentimes bushfires are beyond the capabilities of emergency services, and are extinguished only with the arrival of cooler temperatures and rainfall(Smith et al., 2009). Topography can act to both hamper and enhance the fire environment. Dry inland salt lakes can create natural fire breaks, giving bushfires nowhere to spread to, given their lack of vegetation(O’Donnell, 2009). Conversely, fire can spread as much as 2-3 times as fast upslope as it can downslope, so topography can play a very vital role in bushfire management, particularly in mountainous alpine areas(Hasson et al., 2008). Fuels themselves are any form of ground vegetation capable of igniting or spreading a bushfire(DEC, 2011). Some characteristics of fuels to be considered are fuel loading, the compactness of the fuels, fuel size, fuel shape, fuel (vegetation) type, and the horizontal and vertical extent of fuels(DEC, 2011).
The occurrence of bushfires in Australia is mistakenly thought to be primarily in the southern regions. However, research has shown that bushfires occur primarily in savannah landscapes of Tropical Northern Australia, which experiences monsoonal influences(Russell-Smith et al., 2007). The study from Smith et al. utilized both Fire Hot Spot (FHS) and Fire Active Area (FAA) datasets, mapping daily fire activity with use of algorithms and 9-day burnt areas due to the orbital pass of the NOAA-AVHRR platform, respectively. Smith et al. omitted nearly 90% of all individual fires acquired with the FAA method due to the level of error associated with the relatively small size of these fires, however in doing so, found that these fires accounted for less than 3% of the total burnt area. Figure 1 shows the Seasonal (quarterly) distribution of FHS from 2002(Russell-Smith et al., 2007). Figure 2 shoes the frequency of large fires derived from FAA mapping, from 1997-2004(RussellSmith et al., 2007). The circled area represents the 2002-2003 southern Australian bushfires. It should be noted that the FAA data was acquired from 1997-2004 for the entire country, and from 1990-2004 for Western Australia and Northern Territory. For this particular study, only the years 1997-2004 were used.
Figure 1(Smith et al.)
Figure 2(Smith et al.)
An analysis of two separate bodies of researched focussed primarily on climate change implications on bushfire management in the twenty-first century discuss some of the weather-related reasons for Australia’s high degree of susceptibility to bushfires. Hennessy et al. conducted a study using historical weather data from 1974-2003 provided by the Australian Bureau of Meteorology (BOM) to generate climate change scenarios for 2020 and 2050, and to subsequently determine the likelihood of increased risk from bushfires in the twenty-first century. The study concluded that the occurrence of very high and extreme fire weather days could increase from 4-25 percent by 2020 and from 15-70 per cent by 2050 across some regions of SE Australia. It also suggested that elevated fire weather risks in spring, summer, and autumn could encourage more winter prescribed burning in future years, as well as to extend the annual bushfire season(Hennessy et al., 2006).
Hasson et al. looked at potential high-impact fire days by modelling changes to temperature regimes in the twenty-first century under different emissions scenarios, coupled with “strong cold front” days, as research has shown that most high-impact fire weather events in the past 40 years in SE Australia, which experiences summer conditions similar to those found in Western Australia, have been associated with strong cold frontal passage(Hasson et al., 2008) under low- and high-impact scenarios for two twenty-year periods, 2050 and 2090. The results of this research showed an increase in temperature during both twenty-year periods, and under both scenarios. It was a recommendation from this body of work that these scenarios be taken into consideration for future fire management planning.
A very different body of research looked at the effects of topography, vegetation type, fuel age, and social factors as varying effects on the fire environment of South Western Australia(O’Donnell, 2009). The study showed that fuel frequency decreased in wooded regions as compared to mallee and shrub land vegetation, with an increased probability of fire occurrence with increased fuel age. There was also a relationship found between extensive fire activity (> 100,000Ha) and rainfall regimes; it was found these extensive fire activity periods were associated with below-average rainfall, and also that they were preceded by a year of above-average rainfall and low temperatures(O’Donnell 2009). This indicates an occurrence of building and subsequent drying of large amounts of fuel, leading to greater fuel loads and environments more conducive to bushfires.
When dealing with the description of, management of, or discussion of a fire regime, it is necessary to distinguish an actual bushfire, or wildfire, from a planned and managed prescribed burn. A bushfire is an unplanned fire, while a prescribed burn, as defined by the Department of Environment and Conservation under the government of Western Australia, is “the controlled application of fire under specified environmental conditions to a predetermined area…”(DEC, 2011). With regards to emergency management for bushfires in Western Australia, the approach has seen changes in recent years, including this year. There are multiple agencies with varied, and sometimes varied roles with regards to bushfire emergency management. The state is divided into regions, and those regions into districts, each with a regional fire coordinator (RFC) and district fire coordinator (DFC), respectively, responsible for the fire management activities of their respective regions or districts (Figure 3).
Figure 3(Bryce Touchstone, Department of Environment and Conservation, Fire Management Services).
The primary method of bushfire mitigation is with an extensive, cross-regional prescribed burn plan, organized and overseen by the Department of Environment and Conservation (DEC), and carried out and reported on by the responsible RFC and DFC. The Fire Management Services (FMS) branch of DEC delivers extensive GIS services, specifically mapping products, to field personnel with regards to fuel age, planned versus carried out prescribed burn, burn area, etc. to assist with each region’s seasonal prescribed burn plan. The BOM issues seasonal climate outlooks, and specific bushfire outlooks, as well as daily bushfire conditions and warnings in the event of potential bushfire activity. This information coupled with that provided by DEC is utilized on a daily basis by RFC’s, DFC’s, and field personnel to determine what, if any, prescribed burn activities will take place on that day.
The Fire and Emergency Services Authority of Western Australia (FESA) is the primary agency within Western Australia that handles the preparation and response phases of bushfire emergency management state-wide. FESA has published ‘Prepare. Act. Survive’, a comprehensive guide to ‘preparing for and surviving the bushfire season(FESA, 2011), which includes information on their three-step bushfire readiness scheme, prepare, act, and survive, and several, but equally important checklists including Important Contacts, Preparing Your Survival Kit, Preparing Your Property, Total Fire Bans Fact Sheet, Leaving For a Safer Place, Preparing to Actively Defend, and Planning to Actively Defend(FESA, 2011).
The government has a policy of either evacuate or ‘Stay and Defend’ with regards to bushfires. FESA and DEC both issue information regarding home preparation for ‘Stay and Defend’ scenarios, and FESA published a document on methods of preparing a home for ‘Stay and Defend’, among which are fire breaks around the perimeter of the residence, a vegetation-free buffer within the residence, and specific fire ember-resistant air conditioner units(FESA, 2011). FESA is also the primary agency responsible for emergency response to cyclones, storms, floods, earthquakes, tsunamis, hazardous materials, and search and rescue incidents; as such, they have a number of warning and information dissemination systems, including the Standard Emergency Warning Signal (SEWS), a distinctive siren sound used to alert the target community of relevant safety information regarding a current disaster or emergency, and StateAlert, an automatic, web-driven service which delivers automatic emergency- and disaster-related information directly to landlines and registered mobile phones.
The BOM issues a range of bushfire risk warnings within the framework of the Fire Danger Rating(FESA, 2011). Bushfire danger ratings range from Low-Moderate, High, and Very High, to Severe, Extreme, and Catastrophic. From this and other information, FESA issues a Bushfire Warning, which operates within a framework of Advice, Watch and Act, Emergency Warning, and All Clear(FESA, 2011). It should be noted that ‘Stay and Defend’ is not advised for Fire Danger Ratings above Severe, as homes are not capable of being built to withstand bushfires in these conditions. FESA is also primarily responsible for managing Total Fire Bans, as well as partnering with DEC in advising remote farmers and northern property owners of properties of substantial size on prescribed burn and winter burn activities. Prescribed burn and winter burn is allowed to be carried out privately within certain restrictions, which include all private parties first consulting with their local council or shire and remaining vigilant of the fire environment and its capabilities during the week of the planned burn.
Prior to February 2011, FESA was an independent agency, outside of government control. In February 2011 a devastating bushfire in the Perth Hills of Western Australia, while claiming no lives, destroyed more than 70 homes. As a result, on 23 February, WA Premier Colin Barnett ordered a review of the incident, and the inter-agency response, and a subsequent delivery of the report of findings and recommendations. This task was assigned to former Federal Police Chief Mick Keelty. The inquiry involved over 50 hearing with more than 100 witnesses over a period of 2 months, at local Kelmscott, Roleystone, and Armadale civic centers, among over venues. The report, titled ‘A Shared Responsibility: The Report of the Perth Hills Bushfire February 2011 Review’, was submitted in August 2011, and noted multiple deficiencies on the part of FESA in working alongside DEC and volunteer fire fighters, and a lack of information sharing. It also found that evidence provided by FESA was in many instances an attempt to hide FESA shortcomings. Among the results of the report were 55 recommendations, among which were better inter-agency operations and communications, and that FESA’s board be disbanded and FESA itself be brought under government control. FESA’s board was disbanded, its chief executive sacked, and FESA itself was later made into a government agency.
It is worth noting one final update just prior to the writing of this paper. On 23 November, 2011, dormant prescribed burns in the Margaret River jumped control lines under catastrophic fire weather conditions, creating a bushfire that destroyed over 30 homes. Also across the southern region in the subsequent four days, 24-27 November, four other bushfires burned over 100,000Ha of land. It was found that the government had only 9 of the 55 recommendations from the Keelty Report had been implemented prior to the 2011 summer bushfire season. Having been part of the response to those incidents firsthand, as a member of DEC Fire Management Services, the relationship between DEC and FESA was, and will continue to be tested; this is a situation that will no doubt require effort on the part of all parties involved.
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References
Bureau of Meteorology, cited 2011: Living with Drought.
[http://www.bom.gov.au/climate/drought/livedrought.shtml].
Department of Environment and Conservation, cited 2011: Prescribed burning.
[http://www.dec.wa.gov.au/content/category/49/865/2073/].
Department of Environment and Conservation, cited 2011: Wildfires.
[http://www.dec.wa.gov.au/content/category/49/866/2073/].
Fire and Emergency Services Authority of Western Australia, cited 2011: Your Guide to Preparing For and Surviving the Bushfire Season.
[http://www.fesa.wa.gov.au/safetyinformation/fire/bushfire/BushfireManualsandGuides/FESA_Bushfire-Prepare_Act_Survive_Booklet.pdf].
Fire and Emergency Services Authority of Western Australia, cited 2011: The Homeowner’s Bush Fire Survival Manual.
[http://www.fesa.wa.gov.au/safetyinformation/fire/bushfire/BushfireManualsandGuides/FESA_Bushfire-Homeowners_Survival_Manual.pdf].
Fire and Emergency Services Authority of Western Australia, cited 2011: Fire Danger Rating and What It Means To You.
[http://www.fesa.wa.gov.au/safetyinformation/fire/bushfire/BushfireFactsheets/FESA_Bushfire_Factsheet-Fire_danger_ratings.pdf].
Fire and Emergency Services Authority of Western Australia, cited 2011: Bushfire Warnings: What Should You Do? Survive.
[http://www.fesa.wa.gov.au/safetyinformation/fire/bushfire/BushfireManualsandGuides/FESA_Bushfire-Prepare_Act_Survive_Booklet.pdf].
Hasson, A.E.A., Mills, G.A., Timbal, B., Walsh, K., 2008: Assessing the impact of climate change on extreme fire weather in southeast Australia. CAWCR Technical Report No. 007, 86 pp.
Hennessy, K., Lucas, C., Nicholls, N., Bathols, J., Suppiah, R., Ricketts, J., 2006: Climate change impacts on fire-weather in south-east Australia. CSIRO & BOM, Libraries Australia ID: 40171855, 91 pp.
Keelty, R., 2011: A Shared Responsibility: The Report of the Perth Hills Bushfire February 2011 Review. Special Inquiry pursuant to s24H(2) of Public Sector Management Act 1994, 211 pp.
MetEd Comet Module, cited 2009: S-290 Unit 1: The Fire Environment.
[http://www.meted.ucar.edu/fire/s290/unit1/navmenu.php?page=2.0.0].
O’Donnell, A., 2009: Historical Patterns of Bushfire in Southern Western Australia. Fire Note, Issue 48, 1-2.
Russell-Smith, J., Yates, C.P., Whitehead, P.J., Smith, R., Craig, R., Allan, G.E., Thackway, R., Frakes, I., Cridland, S., Meyer, M.C.P., Gill, A.M., 2007: Bushfires ‘down under’: patterns and implications of contemporary Australian landscape burning. Int’l. Jnl. of Wildland Fire, 16, 361-377.
Smith, K., Petley, D., 2009: Biophysical Hazards. Environmental Hazards Assessing risk and reducing disaster, Routledge, 221-230.
