ACRIS Fire Product Update 2006-2010
Updated information to that provided in
Rangelands 2008 – Taking the pulse
Gary Bastin, ACRIS Management Unit
CSIRO, PO Box 2111, Alice Springs NT 0871
(email: Gary.Bastin@csiro.au)
This project is supported by Ninti One Limited,
through funding from the Australian Government's Caring for ou Country.
1
The views and opinions expressed in this publication are those of the authors and do not
necessarily reflect those of the Australian Government or the Minister for Sustainability,
Environment, Water, Population and Communities.
While reasonable efforts have been made to ensure that the contents of this publication are
factually correct, the Commonwealth does not accept responsibility for the accuracy or
completeness of the contents, and shall not be liable for any loss or damage that may be
occasioned directly or indirectly through the use of, or reliance on, the contents of this
publication.
2
Mapping of fire scars from NOAA AVHRR satellite data by the WA Land Information
Authority (Landgate) allows ACRIS to periodically update the fire record for the rangelands.
This brief report updates the rangelands-wide fire record between 2006 and 2010 and follows
the presentation style used in Rangelands 2008 – Taking the pulse (Bastin et al. 2008) for
reporting fire regime between 1997 and 2005.
Key points
The continued mapping of fire scars from satellite imagery has allowed ACRIS to update the
fire record for 2006 through 2010. A complete fire record for the rangelands now exists
between 1997 and 2010. Fire extent and frequency continue to vary considerably across the
rangelands. Notable differences include:

Fire continues to be widespread and frequent in much of northern Australia when
there is little rain during the dry season. Much of this burning appears to be
uncontrolled, occurring in the late dry season when fires are more extensive and quite
intense. However there is evidence for some northern bioregions that the extent of
cooler fires in the early dry season is increasing. Such burning should mitigate the
extent and severity of hotter fires in the late dry season.

Fire was relatively more extensive in north east Queensland in 2008 and 2009
following high rainfall over the preceding summers. For example, 3.8% and 4.7% of
the Brigalow Belt North and 5.0% and 6.0% of the Desert Uplands bioregions burnt in
2008 and 2009 respectively. Median annual fire extent (between 1997 and 2010) for
the Brigalow Belt North is 0.7% and for the Desert Uplands, 1.9%.

In the semi-arid and arid parts of central Australia, there has been little recent fire
activity. This region last experienced extensive episodic fire, particularly in the
western deserts, following the sequence of wetter years at the start of the most recent
decade.

Fire was generally minimal and infrequent across most of the southern rangelands.
Fire extent
Northern bioregions continued to have much of their area burnt in each of the calendar years
2006-2009 (Figure 1) with fire extent considerably reduced in 2010. This reduced fire
incidence in 2010 was probably due to rainfall persisting into the early dry season (April and
May) and the following wet season starting early (limited rainfall between July and
September with amounts increasing in October and November, Figure 2).
In those recent years when fire was more extensive (2006-2009), the Pine Creek bioregion
had the largest proportional area burnt in each year (average 55.7% of bioregion area burnt
each year). Between 39% and 43% of the Victoria Bonaparte, Central Arnhem, Northern
Kimberley and Daly Basin bioregions burnt on average each year between 2006 and 2009.
There was a similar pattern of annual fire extent at sub-IBRA resolution: fire was less
extensive in 2010 compared with the four preceding years. Averaging fire extent across this
period (2006-2009), fire was most extensive in the Northern Holroyd Plain subregion of the
Cape York Peninsular IBRA (61.5% area burnt each year) followed by the Pine Creek IBRA,
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Victoria Bonaparte P2 sub-IBRA and Weipa Plateau (Cape York Peninsular) (51% to 56% of
sub-IBRA area burnt, on average, each year). Maps of annual fire extent by sub-IBRA are
shown in Appendix 1.
Figure 2. Spatially averaged monthly rainfall for the northern fire-intensity region (see map
included with Box 1 for region extent). Rainfall is shown for 2010 and the long-term median
(1890-2010).
Data: Bureau of Meteorology. Graphs: the ACRIS-MU.
4
no data
60
45
bioregion not burnt
>60% of
bioregion burnt
30
15
0
1% or more of
bioregion burnt
Figure 1. Fire extent shown as the percentage area of bioregions burnt between 2006 and 2010.
Corresponding maps of percentage area burnt between 1997 and 2005 are at page 72 of Rangelands 2008 –
Taking the pulse.
Data: WA Landgate. Maps: ACRIS-MU.
5
Box 1: Monitoring fire scars in the rangelands
The extent of fire scars has been mapped on a monthly basis using satellite imagery covering
most of Australia’s rangelands. These satellite data are acquired by the WA Land
Information Authority (Landgate) and provide a course national overview of fire using
NOAA AVHRR (1.1 km x 1.1 km). This technology is less sensitive to small scale or patchy
burns, and results from some prescribed or ‘cool’ burns at this scale may not be detected
given its coarseness.
Landgate has provided updated statistics on the monthly and annual extent of fire scars in
each rangeland bioregion, by sub-IBRA region, for each year since 1997. Fire frequency is a
spatial averaging of the number of times an area (pixels in a satellite image) burnt over the 14
years between 1997 and 2010 (see Box 2 for example calculations).
At the regional scale, fire data were highly reliable based on ground checks, acknowledging
the difficulties in mapping small fires with the coarse resolution of the AVHRR data. Also,
‘cooler’ burns may be difficult to detect, particularly where there was tree cover and the
crown was not burnt (e.g. woodlands). For regional reporting, these limitations in mapping
fire scars are less critical than for local evaluations.
Fire intensities were evaluated as being hot or cool depending on the month in which a fire
occurred in northern versus central and southern rangeland regions (below map), where:
Regional Grouping
Northern
Central & Southern
Fire Intensity
Months
Hot
August to December
Cool
January to July
Hot
December to March
Cool
April to November
Geographic grouping of bioregions for categorising fire intensity
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Fire intensity
Fire intensity was defined for Rangelands 2008 – Taking the pulse by month of burn (details
in Box 1). The most recent data are included for the four example bioregions used in that
report to illustrate differences in fire intensities across Australia’s rangelands (Figure 3).
Regional fire intensities since 2005 for the four bioregions lie within the range that had
operated over the preceding nine years (i.e. 1997-2005).

‘Hot’ (i.e. late dry season) fires were extensive in the Central Kimberley bioregion
between 2006 and 2009 relative to the 1997-2005 fire regime with very little fire in
the latter part of 2010 due to increased rainfall. The area burnt by cooler fires was
relatively stable between 2007 and 2010 with ~10% of bioregion area burnt each
year.

Hot fires continued to predominate in the Central Arnhem bioregion in 2006 and
2007 but the proportional area burnt by cooler early-dry-season fires increased
appreciably in 2008 and 2009.

For the Desert Uplands (north east Queensland), there was a spike in the extent of
hot fires in 2008 and 2009. Presumably, this was due to wet season rainfall being
much above average during the preceding two summers thereby increasing fuel
loads.

There has been minimal fire activity in the Burt Plain bioregion (southern NT) in
recent years.
Fire frequency
For each rangeland bioregion, fire frequency was calculated as the number of times each area
burnt between 1997 and 2010 (see Box 2 for example calculations). These data were log10
transformed to improve the information content of mapped fire frequency (Figure 4). As
reported in Rangelands 2008 – Taking the pulse, the northern rangelands continued to burn
most frequently and those in southern areas infrequently. For example, the Pine Creek and
Daly Basin bioregions (both northern NT) had the highest fire frequencies (log10 transformed
values = 0.871 and 0.806 respectively). Several bioregions in the southern rangelands had a
nil or very low fire frequency over the 1997-2010 period.
Fire frequency changes with the length of the reporting period so values for some bioregions
in the 1997-2005 period (reported in Rangelands 2008 – Taking the pulse) are different to
those for 1997-2010 (Appendix 2).
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70
70
cool burn
hot burn
60
60
50
50
% bioregion burnt
% bioregion burnt
cool burn
hot burn
40
30
40
30
20
20
10
10
0
0
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
1997
1998
Central Arnhem bioregion
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2008
2009
2010
Central Kimberley bioregion
30
10
cool burn
hot burn
9
cool burn
hot burn
8
25
% bioregion burnt
% bioregion burnt
7
6
5
4
20
15
10
3
2
5
1
0
0
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Desert Uplands bioregion
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
Burt Plain bioregion
Figure 3. Percentage area of selected bioregions burnt by ‘hot’ and ‘cool’ fires in the period
1997-2010.
Data: WA Landgate. Graphs: the ACRIS-MU.
Figure 4. Fire
frequency for
bioregions burnt
between 1997 and
2010. Note that
mean fire frequency
values for each
bioregion are
mapped as log10.
Data: WA Landgate.
Maps: the ACRISMU.
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Box 2. Fire frequency in the rangelands
Fire frequencies over the 1997 to 2010 period for each rangeland bioregion were calculated
using the following diagrams supplied by the WA Land Information Authority (Landgate).
Assume that a 3 by 3 array of pixels and lines (below table) represents the area extending
across a region. Burnt pixels were represented by the value “1” and unburnt pixels by “0”.
In the year 1999, two thirds of the array was burnt and in 2000, a little more than one third
was burnt. The fire frequency across the two years is calculated by summing pixel values.
Year 1999
Year 2000
Fire Frequency
0
1
1
0
0
0
0
1
1
0
1
1
0
1
1
0
2
2
0
1
1
0
1
1
0
2
2
Two examples of calculating fire frequencies are presented.
In Example 1, the region is represented by four pixels within the solid line.
0
1
1
0
2
2
0
2
2
The average fire frequency for this example region is (2+2+2+2)/4 = 2.0
In Example 2, the region is represented by six pixels.
0
1
1
0
2
2
0
2
2
The average fire frequency for this region is (0+0+2+2+2+2)/6 = 1.3
The spatially-averaged fire frequency data for bioregions have a large and skewed range.
Average fire frequency is relatively high in the north and very low in the south. To improve
mapping detail, these data have been log10 transformed by the ACRIS-MU (Figure 4).
9
Reference
Bastin, G. & the ACRIS Management Committee (2008). Rangelands 2008 – Taking the
Pulse. Published on behalf of the ACRIS Management Committee by the National Land
and Water Resources Audit, Canberra. Available at:
http://www.environment.gov.au/land/rangelands/acris/index.html
10
Appendix 1: Fire extent by sub-IBRA
Maps of the percentage area of each rangeland sub-IBRA burnt annually between 1997 and 2010 are
shown below and on the following page.
11
no data
60
45
bioregion not burnt
>60% of
bioregion burnt
30
15
0
1% or more of
bioregion burnt
Appendix 1. Fire extent shown as the percentage of sub-IBRA area burnt between 1997 and 2010.
Data: WA Landgate. Maps: ACRIS-MU.
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Appendix 2: Change in fire frequency by bioregion for two reporting periods
Fire frequency changes with the length of the reporting period so values for some bioregions in the 1997-2005 period (reported in Rangelands 2008 –
Taking the pulse) are different to those for 1997-2010.
IBRA
Arnhem Coast
Arnhem Plateau
Brigalow Belt North
Brigalow Belt South
Broken Hill Complex
Burt Plain
Cape York Peninsula
Carnarvon
Central Arnhem
Frequency
1997-2010
4.895
3.921
1.164
1.114
1.020
1.225
4.453
1.060
5.411
Frequency
1997-2005
3.247
2.66
1.096
1.018
1.033
1.071
2.812
1.052
3.787
Difference
Comments
1.648
1.261
0.068
0.096
-0.013
0.154
1.641
0.008
1.624
substantial increase with continuing extensive fire between 2006 & 2009
moderate increase with extensive fire in 2006, 2008 & 2009, less so in 2007
low fire incidence, little change in fire frequency
low fire incidence, little change in fire frequency
low fire incidence, no real change in fire frequency
low fire incidence, small increase in fire frequency
substantial increase with continuing moderately extensive fire in between 2006 & 2009
low fire incidence, no real change in fire frequency
substantial increase with extensive fire in 2007 & 2009 and moderately extensive fire in
2006 & 2008
small increase - continuing extensive fire in between 2006 & 2009
low fire incidence, no real change in fire frequency
low fire incidence, no real change in fire frequency
low fire incidence, no change in fire frequency
low fire incidence, no real change in fire frequency
large increase with continuing extensive fire in 2006, 2007 & 2009; moderately
extensive fire in 2008 & 2010
small to moderate increase with continuing extensive fire between 2006 & 2009
low fire incidence, no real change in fire frequency
substantial increase with extensive fire in 2008 & 2009 and moderately extensive fire in
2006, 2007 & 2010
moderate fire extent in 2007, less so in 2006 and little fire in other years, small increase
in frequency
small increase - fire more extensive in 2008 & 2009
small increase - fire more extensive between 2007 & 2009
low fire incidence, no change in fire frequency
no fire scars mapped until 2009
Central Kimberley
Central Ranges
Channel Country
Cobar Peneplain
Coolgardie
Daly Basin
4.322
1.325
1.093
1.000
1.033
6.397
3.646
1.31
1.091
1
1.011
4.436
0.676
0.015
0.002
0.000
0.022
1.961
Dampierland
Darling Riverine Plains
Darwin Coastal
4.432
1.174
5.154
3.658
1.168
3.56
0.774
0.006
1.594
Davenport Murchison
Ranges
Desert Uplands
Einasleigh Uplands
Finke
Flinders Lofty Block
1.666
1.321
0.345
1.223
1.898
1.030
1.000
1.083
1.541
1.03
0.140
0.356
0.000
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IBRA
Gascoyne
Gawler
Gibson Desert
Great Sandy Desert
Great Victoria Desert
Gulf Coastal
Gulf Fall and Uplands
Gulf Plains
Hampton
Little Sandy Desert
MacDonnell Ranges
Mitchell Grass Downs
Mount Isa Inlier
Mulga Lands
Murchison
Murray Darling
Depression
Northern Kimberley
Nullarbor
Ord Victoria Plain
Pilbara
Pine Creek
Riverina
Simpson Strzelecki
Dunefields
Stony Plains
Sturt Plateau
Tanami
Tiwi Cobourg
Victoria Bonaparte
Yalgoo
Frequency
1997-2010
1.101
1.000
1.318
1.467
1.165
4.110
3.271
2.761
Frequency
1997-2005
1.092
1
1.12
1.37
1.13
2.752
2.314
2.008
Difference
0.009
0.000
0.197
0.098
0.034
1.357
0.957
0.754
Comments
low fire incidence, no real change in fire frequency
very low fire incidence, no change in fire frequency
small increase - some fires in 2006 reducing in latter years
small increase – moderately extensive fire in 2006 reducing in latter years
low fire incidence, little change in fire frequency
moderate increase - extensive fire in 2007 & 2009, less so in 2006, 2008 & 2010
moderate increase - extensive fire in 2007 & 2009, less so in 2006, 2008 & 2010
moderate increase - moderately extensive fire 2006, 2007 & 2009; less so 2008, 2010
no fire record
small increase with some fire in 2006 & 2007
low fire incidence, no change in fire frequency
low fire incidence, little change in fire frequency
small to moderate increase - moderately extensive fire in 2006
low fire incidence, no change in fire frequency
low fire incidence, little change in fire frequency
low fire incidence, no change in fire frequency
1.254
1.014
1.187
1.822
1.054
1.101
1.000
1.16
1.014
1.107
1.337
1.054
1.069
1
0.094
0.000
0.080
0.485
0.000
0.032
0.000
5.614
5.094
0.520
1.014
2.752
1.683
7.429
1.000
1.006
1.091
2.217
1.448
4.917
1
1.005
-0.077
0.535
0.234
2.512
0.000
0.001
previous fire frequency calculated for 1993-2005 - hence a different comparison period.
Extensive fire in 2007 & 2008, moderately extensive in other recent years
low fire incidence, no real change in fire frequency
small increase with moderately extensive fire in 2006, less so in subsequent years
small increase - moderately extensive fire in 2006, reduced fire extent in recent years
large increase with continuing extensive fire in all years
low fire incidence, no change in fire frequency
low fire incidence, no change in fire frequency
1.000
4.059
2.251
3.722
4.868
1.000
1
2.723
1.894
2.403
3.599
1
0.000
1.337
0.357
1.319
1.269
0.000
very low fire incidence, no change in fire frequency
moderate increase with extensive fires in 2006, 2007 & 2009
small increase with moderately extensive fire in 2006 & 2007, reduced fire extent since
moderate increase with continuing moderately extensive fire in all recent years
moderate increase with continuing extensive fire in 2006 to 2009
low fire incidence, no change in fire frequency
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