25 November 2007

Australian Bushfire Activity: 7-16 Nov 2007

Below is the latest 10-day hotspot composite for Australia from the NASA MODIS Rapid Response Global Fire Mapper website. The hotspots were compiled over the period from 7-16 November 2007.

Over the period, the major focus of fire activity in Australia remains in the northern portion of the continent, primarily NT and QLD. Comparing to previous maps, a distinct reduction in fire activity over the Top End is noted.

In QLD, many of these fires were reported in the last national update, particularly those in the Gulf and central portions of the state. Most of the fire noted in that region went out shortly after the date of the last report (which was 2 days into the current period). The fire activity on the western side of Cape York also continued, although the level of activity is gradually decreasing. Southeastern portions of the Peninsula, near Cooktown, continued to burn.

As before, the central coastal and southeastern regions of the states continued to see isolated hotspots, but no major fires have been reported or identified.

The Gulf country regions of both QLD and NT remained quite active, particularly on the NT side of the border. There are two main areas in NT near the coast -- one about 40 km NW of Booraloola, the other about 100 km to east of the town. These fires were roughly 60 000 to 100 000 ha in size. Fires also continued in eastern Arnhem Land, near the coast.

Across a broad swath of the western Top End, extending inland into central NT, some significant rain was observed early in the month. This has helped damp down the fire activity in those regions. Still, lightning did likely initiate some storms in Central NT, near Yuendumu, as discussed in this post.

Over in WA, significant fires continued to burn in west Kimberley, 100 km (or so) to the east of Derby. In the northern reaches of the Great Sandy Desert, a large fire burnt for most of the period, encompassing on the order of 500 000 ha. Several other large fires were noted to the east of this regions, out towards the general vicinity of Halls Creek and towards the NT border. The largest of these fires were on the order of 50 000 to 80 000 ha of area burnt.

The Pilbara region of WA also saw some bushfire activity during this period. This was widely scattered throughout the region. While widely scattered, some of these fires did affects areas on the order of perhaps 20 000 to 40 000 ha. Similarly in the southern deseret regions of WA, north of the Nullarbor and east of Laverton.

In the southwestern part of the state, multiple hotspots are seen in the forests of the region. One fire, in the Jarrah forest near Collie, was believed to have been deliberately lit. Others may be controlled burns, although in some cases these are wildfires likely wildfires.

Tasmania also saw some significant wildfire activity during this period. Several widely spaced hotspots are visible in the composite. Several difficult to control fires were reported on the Tasmanian West Coast, near Strahan and Zeehan. Arson is suspected in these fires.

A few scattered hotspots are noted in NSW, especially the NE corner and VIC. Interestingly, the greatest density of hotspots in both states are over Sydney and Melbourne. These are obviously spurious hotspots, die to some other cause. There have been no bushfires within the city limits of either town during this period. I actually did notices the Sydney example when scanning MODIS imagery...They all occurred in one overpass, suggesting they are not individual house fires or some such occurring over the entire period. There are many known errors associated with the hotspot detection. See the FAQ on the NAFI page for a start...

A Word on Size Estimates

Earlier, while looking at at some of the size calculations, I noticed a few discrepancies between areas I computed earlier using the spot information in NAFI and the later fire scar information. Namely, the fire scar estimates seemed to be lower, by perhaps as much as 25% lower. I don't fully understand the source of this difference-- for example,it could be the large symbols covering too much area or parts of the automatic fire scar mapper missing some burnt areas or just general sloppiness/imprecision on my part. There are differences in the resolution of the data used to compute the two different things, with higher resolution data in the fire scars. Whatever the cause, it provides some sort of useful bound on the accuracy of the estimates (say +/- 20% or so in the worse case). I always use agency estimates when available, and compare with other published sources when I can. This is probably not a major issue for most of you, but it should be kept in mind

21 November 2007

Southeast bushfires update

In TAS, the South West Conservation Area fire has grown during the day, having now burnt 2 400 ha. Smoke from the fires affected Hobart today, as seen in the photo. Rain and cooler conditions are expected overnight and tomorrow, hopefully allowing firefighters to gain control over the blaze.

The Little Desert in western VIC are now burning within containment lines. It has burnt 15 990 ha. The Lascelles-Wathe fire is still listed as 'Going' with 4 000 ha burnt. Conditions tomorrow are expected to be cooler, but winds are forecast to remain strong. Moderate to High fire dangers remain.

A fire in the Riverland region of SA, the Bruno Bay fire, has been burning for a few days. It has burnt more than 900 ha and has now been brought under control. The earlier expected threat to nearby towns did not materialize today, and the danger has likely passed.

The Prill Park-Euston bushfire in southern NSW has also been contained.

19 November 2007

VIC, TAS bushfires: 19 Nov

As expected, fire activity was widespread throughout Victoria and Tasmania today. Maximum temperatures were above average across much of the region and fire danger ratings climbed into the very high to extreme range across much of the area, including northern SA, western VIC , southern NSW and Tasmania. Several media reports were made.

Seven fires are burning out of control across Victoria as temperatures soar into the high 30's.

As of this evening (19th), the two main fires listed yesterday remain uncontrolled. The DSE indicates that both have essentially doubled in size today, with the Little Desert fire now at 15 000 ha and the Lascelles-Wathe is at 4000 ha. The Prill Park-Euston fire just across the border in NSW is reported as 'Being Controlled”, with a size of 1500 ha being reported. A small bushfire was also reported in northern VIC, near Shepparton.

In Tasmania's south-west conservation area the Adamsfield walking track is being threatened by another bushfire.

Fire officers are blaming a lightning strike for the 340 hectare fire in button grass moorland, about 30 kilometres west of Maydena.

At Cradle Mountain, Parks and Wildlife crews are monitoring a blaze at Middlesex Plains on Cradle Mountain Road.

That fire has consumed 235 hectares but crews say there is no threat to life or property.

The South West fire and Cradle Mountain fire are listed as 'going' tonight on the Tasmania Fire Service website. Several others are listed, but they are contained or being patrolled. The image is from that site and shows the area burnt (500 ha) in the South West fire.

Fire weather conditions are expected to be very high to extreme across much of the regions tomorrow, as well, with temperatures in the 30s and gusty, northerly winds ahead of a frontal passage in the afternoon.

Weekend Victoria fires; threat continues

Multiple fires reported in western VIC and SA today area over the past two days. Fire conditions have been in the very high to extreme, and fire bans have been issued for portions of SA.

In Victoria, 20 bushfires were sparked on Saturday. Including several in small fires in Gippsland (eastern VIC) which remain listed as 'Going' as of Sunday night (DSE webpage) and one near the main water catchment for Melbourne which required water-bombing.

The largest fires were (and are) in the western portion of the state. These are seen in the MODIS 'Australia5' subset image from the Aqua satellite, captured this afternoon around 1445 LT. Sizes are current as of 2000 LT as gathered from the DSE Fires Today website. Two hotspot areas are seen; the southern-most one is the 'Salt Lake Track' fire in the Little Desert National Park. It has burnt 7000 ha and is not under control at this time. The most northerly Victorian fire is the Lascelles-Wathe fire, which has burnt 2000 ha and also remains uncontrolled.

The fire in NSW is listed as the 'Prill Park Euston' fire on the Current Incidents page of the NSW RFS. No size information is given, but the fire is listed as going. (but that update is fairly old...)

Tomorrow (the 19th) will likely be another big fire day across much of the region. Fire weather warnings (and fire ban in some cases) are in effect for southern NSW, northern SA and the Flinders Ranges, eastern Tasmania and western VIC. Temperatures are also high in other areas (37 C in Melbourne!), and fire danger should be enhanced (although no warnings are in effect).

15 November 2007

New central NT fires

Over the past week or so, a new round of large fires has cropped up in central portions of NT. Some imagery showing the time evolution of some of these fires is shown below. These images are cut from the NASA MODIS subsets on the day indicated. The pixel size is 1 km, and the image is 500 x 325 pixels. The area extracted is identical in each image.

In the western portions of the territory, about 70 km NW of Lajamanu, a rapidly burning fire is underway. Reviewing MODIS imagery suggests this fire started on 11 November, when a few isolated hotspots were seen. On the 12th, the Terra satellite passed over at 0145 UTC (1115 local time) with only a few hotspots detected. By the time of the Aqua overpass approximately 3 hours later, the fire had undergone a massive expansion. The NAFI map and imagery from earlier today suggested continued expansion towards the SW and on the northern portions. The total are affected to date is about 180 000 ha. Conditions today were not as severe as past days, although fire danger ratings were generally in the high to very high category.

More centrally located, to the north of Elliott and west of Daly Waters, two broad areas of fire are noted in the current image, a large L-shaped one to the east and a smaller area to the west. The eastern area was initially two separate fires which have since merged their burnt areas. This duo of fires was initially detected on 7 Nov, as well as an additional one south of the duo, closer to Elliott. The image from that day shows some prominent smoke plumes streaming off to the west. particularly the northernmost one. The fire closer to Elliott also shows a plume, but it went out over the next day.

The western most was initially spotted on the 8th. By the 9th, this fire had become well established. Areas of the three fires on the 9th were: eastern – 26 000 ha; central – 100 000 ha; eastern – 70 000 ha.

On the 11th, the two western areas began to merge and moved toward the north, creating the L shape. This tendency continued on the 12th, with the northern extent of the L and the western fire showing distinct smoke plumes. On the 13th, the region was covered by clouds in one image and out of the satellite swath in the other. The image from the 14th is partially obscured by clouds, expecially the western fire. Hence, its status is not clear, although there are a few detected hotspots in the vicinity. It's affected area is roughly 140 000 ha. The eastern 'L' fire continues to burn along a long eastern flank. It's total affected area is on the order of 400 000+ ha.

11 November 2007

Australian Bushfire Activity: 28 Oct - 6 Nov 2007

Below is the latest 10-day composite hotspot image for Australia from the NASA MODIS Rapid Response Global Fire Maps. The dates of the composite from 28 October through 6 November 2007.

During this period, fire activity is focused in the northern portion of the continent, particularly in QLD, from the Cape York Peninsula and into the Gulf Country regions of the state. Although numerous fires are burning, no reports of Significant Fire Activity of have been made on the QFRS web site...

The fire level of fire activity on Cape York is about the same as noted in the previous composite. These are generally relatively separate fires rather than a huge organized burning area. A broad range of activity is seen from Auruku down south towards Kowanyama. Similarly, the broad area abour 150 km WNW of Cooktown is also two or three smaller fires. These were also reported in the last update.

New fires are seen further south in Queensland, toward the Gulf Country and Central Queensland regions, east of Normanton and in the vicinity of Croydon. There aqre several individual areas of fire, some quite large. Using archived MODIS imagery from the NASA Rapid Repsonse, the fires in this vicinity appear to have originated around the 30 October. There is evidence of convection in the vicinity on this day, so lightning is a possible ignition source of these fires. On Friday, 9 October (after the period of the composite...), sizes of some of the fires in this vicinity as estimated using the NAFI website were:

  • croydon south 428 000 ha
  • croydon west 62 000 ha
  • miranda downs 220 000 ha
  • strathmore 60 000 ha
  • strathmore east 70 000 ha
  • highbury south 165 000 ha
  • waitan 75 000 ha

In the remainder of eastern Queensland, isolated hotspots are observed. No major fire activity is indicated.

In the region of the Gulf straddling the NT/QLD border, the very large fires noted in the last composite have been extinguished. Several smaller areas, near the coast have started during the composite period, and have continued afterwards. Four main areas were seen, ranging in size from 25 000 to 125 000 ha.

Fire activity also continues in much of the NT as well, but is considerably diminished in many areas. Much of the western NT and eastern Kimberley, extending south in the NW SA received an early bout of heavy rainfall, with well above normal totals being seen (which is actually pretty easy to do, as it normally doesn't rain at all...). Eastern portions of Arnhem Land remain active. One large area of 170 000 ha is seen, as well as numerous smaller areas. In the central portions of NT, the 'fast-moving' fire near Rabbit Flat stands out quite prominently (This is how I noticed it...).

There continues to be several large fires burning in west Kimberley. Many of the smaller fires in the east are no longer burning, like due to the precipitation. The remainder of WA is also reasonably quiescent, a few isolated hotspots in the Pilbara, and a few (likely agricultural/ prescribed fires) noted in the forested areas of the SW.

In SA, a contiguous region of hotspots is noted in a very remote region to the NE of the Nullarbor, probably close to the railway. It appears to have occurred on the 28th and 29th of October. Little of interest (other than the hotspots...) is visible in the imagery from those days – no smoke, etc.

The remainder of the country is quiet. Much of the SE has seen significant precipitation during this at least part of this period, likely dampening fire activity for at least a few weeks. The fires note previously in Tasmania, associated with the 'October bump' are out. No major incidents have been reported in NSW since the middle of October, and no incidents are currently listed on the NSW Rural Fire service website. There are a few widely scattered hotspots in the SE; these are likely controlled burns or other short-lived phenomena.

10 November 2007

A fast-moving NT fire

An large and very quick-burning bushfire was seen in late-October in eastern NT. The NAFI website does not record this fire in the real-time fire scar mapper. The fire occurred in a very remote area, about midway between Lajamanu and Yuendumu, roughly 100 km SSE of the AWS at Rabbit Flat. As a very rough estimate,made by estimating the position and shape of the burnt area in NAFI from the satellite imagery, the total area burnt was on 100 000 – 150 000 ha. All told, the fire only burned for 3-4 days and overwhelming majority of the spread of the fire occurred in a roughly 24-h period.

I didn't actually catch this in real-time, as I was still traveling when it occurred. Rather, I have had to track the all the information down approximately two weeks later. AS it is in such a remote area, there are no media reports to work off of.

Below is a set of daily images culled from the “Australia2” MODIS subset image archives. I have excerpted the small area around the fire. The area shown in the various images is the same in all of them. The pixel size is 1 km and the image size is 520 x 240 pixels. The odd-shaped white spot in the southwest corner is Lake Mackay, which straddles the WA/NT border. For a scale, the longest length of the lake, along the diagonal, is about 100 km. The images speak for themselves; I will only add a few comments.


25 October – no fire apparent

26 October – fire begins. Terra image (not shown) is clear, shows small
hotspots. Aqua has clouds, pyrocumulus suggested rising from location of hotspot. Also a small hotspot to SE is seen on the Terra image.

27 October – some small fire spread. Two sets of hotspots in Terra image (not shown). In Aqua image, the eastern hotspot is obscured by pyrocumulus and smoke.

28 October – fire explodes. Huge smoke plume extending to the ESE. The fire to the SE also expands, but not to the extent of the northern area.

29 October – still some hotspots, but no expansion of area. Aqua image (not shown) suggests plume is now traveling to the NW (i.e. From the SE). Terra image shows full extent of fire. Terra image time uncertain, as fire region is between two swaths of data.

30 October (no image)– extensive clouds, but no hotspots or smoke are apparent in breaks. Fire apparently out.


The blowup of the fire between the 27th and 28th was apparently associated with the passage of a deep low in the Bight. Surface charts suggest W to NW winds, which gradually increased from the 26th to the 28th, peaking on the last day. Maximum temperatures were above 40C at both Lajamanu and Rabbit Flat, 2-4 degrees above normal. Fire dangers were approaching extreme (at a minimum!) with fully cured grass and a even a moderate wind. Quite possibly a fire ban was issued for the region. There was one ongoing in SA that day...The fires were possibly started by lightning. The satellite imagery for both the 25th and 26th (archived here) does show some suggestion on convective activity in the general vicinity. Yuendumu reported 20 mm of rain in the 24 hrs to 9am on the 26th, likely of convective origin.

02 November 2007

Australian Bushfire Activity: 18-27 Oct 2007

Below is the latest 10-day composite of hotspots from Australia as presented as the NASA MODIS Rapid Response map. The image identifies all hotspots detected over the 10 days in question by the MODIS instruments on board the NASA Terra and Aqua satellites. The dates of the image are 18 through 27 October.

The main focus of fire activity during this period remained in the NT. The Tanami Desert fires remained visible in the latest image, although it largely appears to be out at this time, with only a few hotspots remaining. The main region of this complex area of fires burnt over 6.5 million hectares (although this is not continuous, somewhat spotty in regions).

The fires in the Gulf regions of NT, earlier reported (several weeks ago) as flaring up, are also seen in the image. Two large areas of fire are seen in the image. The first is 100-200 km south of Ngukurr in the SE Top End, which has affected about 2.5 to 3 million ha of land. The second is about 200 km NNW of Camooweal, on the QLD-NT border. It has affected about 1 million ha. Both fires show recent hotspot activity at this time, although not as intense as before. The NASA Earth Observatory Natural Hazards site presented a MODIS “721” image of the fires here.

Several other large regions of hotspots are noted in SW NT, west of Katherine and through out Arnhem Land.

The Kimberley region of WA, particularly the western portion, also show some large contiguous areas of hotspots. These fires have been burning for quite some time. Elsewhere, a large reward was offered for information on the deliberately lit fires near Kununurra which took more than a week to control.

In the Pilbara, several somewhat isolated areas of fire are noted south of Port Hedland. Further inland, about 100 km SE of Telfer Mining Centre, an area of hotspots encompassing ~200 000 ha is seen.

In the forested regions of SW WA, several hotspots are seen. Unclear what the source of these are, but controlled fuel reduction burns are a likely scenario. Further east, in the broad vicinity of Laverton, WA, a large “ring” of hotspots is seen.

Northern Queensland has also been quite active. Several large areas of fire are noted in the vicinity of Aurukun, along the west coast of the Peninsula. NAFI suggests that this is currently several smaller separate areas/fires, each about 10-50 thousand hectares in size. A large area is also apparent north of Cooktown, although NAFI again suggests that this is several smaller areas which appear merged on the large-scale image. News reports noted fires threatening property were also noted near Cairns and Townsville.

Further south, in south-east QLD, scattered hotspots are seen over a wide area. Fires threatening property were reported near the Gold Coast, in north Brisbane and near Noosa.

This broad region of scattered hotspots extends down into NSW, particularly in the forested areas. These fires are not reported as major incidents, and many may not have even been attended, as suggested by the lack of response (ie. lack of incident names) to some of the more remote fires indicated in this post. Several of the fires noted there (and some that weren't) were also noted in the news, including the Big Badja, a Monaro blaze and the major Mt Kembla fire.

Numerous hotspots are seen in Tasmania, with over 15 bushfires reported in this news article. These fires are due to the so-called October bump, a small (and relatively short lived) rise in fire danger which is typically observed this time of year in TAS. Usually, it decreases again before the onset of the major summer season. This year, many fire are particularly noted in the far SE corner of the state.

Finally, a few widespread hotspots are noted in VIC. These are likely prescribed burns.