Sunday, October 19, 2014

Defining defensible space around homes - based on 2000 bushfire-threatened houses

There's a new paper published in The International Journal of Wildland Fire October about the importance of defensible space around houses. It has some good tips on preparing at the macro scale for bushfires. Unfortunately it costs $25 to get the full text.  Let me know if you have a pdf copy you are willing to share.

Here's part of the abstract:

"Although state and local governments publish specific guidelines and requirements, there is little empirical evidence to suggest how much vegetation modification is needed to provide significant benefits. We analysed the role of defensible space by mapping and measuring a suite of variables on modern pre-fire aerial photography for 1000 destroyed and 1000 surviving structures for all fires where homes burned from 2001 to 2010 in San Diego County, CA, USA. Structures were more likely to survive a fire with defensible space immediately adjacent to them. The most effective treatment distance varied between 5 and 20 m (16–58 ft) from the structure, but distances larger than 30 m (100 ft) did not provide additional protection, even for structures located on steep slopes. The most effective actions were reducing woody cover up to 40% immediately adjacent to structures and ensuring that vegetation does not overhang or touch the structure."

This is the kind of science-based information that we need for making our bushfire preparations maximally effective.  Interesting to note that distances larger than 30m did not provide additional protection, even for structures located on steep slopes, though I guess that could be interpreted to mean that if it was going to burn anyway because of the location on a steep slope, then creating a defensible space out beyond 30m wasn't going to change that.

The Abstract and pdf download can be found here:  http://www.publish.csiro.au/nid/114/paper/WF13158.htm

The citation for the report is:

Syphard, A. D., Brennan, T. J., & Keeley, J. E. (2014). The role of defensible space for residential structure protection during wildfires. International Journal of Wildland Fire. Retrieved from http://dx.doi.org/10.1071/WF13158.

You can find more tips on bushfire preparation at Ignite Change.




Saturday, October 11, 2014

Another citizen bushfire blog

I was contacted today by the owner of the Ignite Change: Bushfire Awareness blog.

Ignite Change is a social initiative to encourage all Australians to be more cautious in their actions this bushfire season because more than 50% of bushfires are caused through reckless human activity.

You can see the blog author's very personal story of loss in the Merimbula fires two years ago here.

It's great to see another blog raising bushfire awareness.  Please have a look at it, and leave a comment if you feel inspired by this effort.

Friday, August 15, 2014

A worsening fire outlook and a 50% chance of an El Nino developing in September

It looks more and more like we are heading into a bad bushfire season.

In our end of the Helidon Hills (Vinegar Hill locality, 5km north of Gatton in the edge of teh Hills) it has been the driest January to June period of the last seven years (we've only been keeping records that long).

In the three months to the end of June we had only 77mm, and in July we had only 2mm.  Quite a few mature trees are showing patches of dead leaves.

In fact the southern two-thirds of Queensland has experienced an extended period of drier than normal conditions according to the 2014 North Australia Bushfire Seasonal Outlook (this link opens a pdf of the report from the Bushfire & Natural Hazards CRC).

According to the Bushfire Seasonal Outlook "Most climate models surveyed by the Bureau of Meteorology along with recent observations continue to indicate El Niño is likely (70 per cent chance) to develop later this year." - suggesting a dry summer and high bushfire risk.
Chances of exceeding the Mean Maximum Temperature [Bushfire Seasonal Outlook Report]
As of the end of July the areas of Above Normal Bushfire Potential for the 2014/20 bushfire season had already been assessed for northern and central Queensland with fairly large areas being rated as having above normal potential.  Regions of South East and  Western Queensland south of latitude  S25º were scheduled to be assessed during the Southern Australia Bushfire Season workshop in August.

 I'm not sure whether or not that assessment has yet been released, but the ABC has published an article this week which predicts that Queensland could be in for one of its worst bushfire seasons in five years.  Here's some of what they said:

"The Bushfire and Natural Hazards Cooperative Research Centre has shown a 50 per cent chance of El Nino weather patterns starting in September, which could potentially see increased fire danger periods, increased fire incidents and an extended fire season. During the last El Nino weather event in 2009, there were 16,000 vegetation fires - a 30 per cent increase compared to the 12,5000 fires seen in an average season. The prediction came as the state launched its official bushfire season today - about three weeks earlier than usual.

 "This weather pattern would mean above average temperatures and below average winter/spring rainfall which would result in increased grass and forest fuel loads," Mr Johnson said. He said people in high danger areas need to have an emergency plan in place. Currently, more than 60 per cent of the state is drought declared, and very dry and hot conditions are creating ideal conditions for fire. Since April, more than 4,900 hazard reduction burns covering in excess of 421,000 hectares have been performed."

Read the whole article here.  I'll keep an eye out for the Above Normal Bushfire Potential for southern Queensland and will post a summary here when I see it.

A couple of days ago I posted an article on our blog about living with and understanding fire risk.  Some time in the next few weeks I'll post something there on our strategy for preparing with and dealing with fire - we are in the process of concurrently updating our strategy and putting it into effect.

Tuesday, August 12, 2014

Smoke at Postman Ridge - afternoon 12 August 2014


 Afternoon 12 August 2014 - Postmans Ridge / Helidon Spa / Withcott ARea

[source: http://emergencyqld.info/#]

Just to let you know that the smoke in the Helidon Spa / Postmans Ridge area is from a fire on Connoles Road, Postmans Ridge.  There are several fire crews in attendance.

NOTE: the screenshot below MAY NOT indicate the precise location of the fire.

From some viewpoints this looks like the smoke is coming from the Hills in the Helidon area.


Seventeen Mile Road / Wallers Road / Mt Cross Alice Creek Area

 There may still be smoke coming from the above area which was the site of a planned burn by QPWS last week.  QPWS were still in attendance yesterday and smoke was visible from the area from many locations.

A permitted burn near this, at the junction of Wallers/Logan Road and Seventeen Mile Road which was lit up on Saturday afternoon may still be contributing smoke in the vicinity.





when it comes to bushfires, we are all neighbours





Friday, April 11, 2014

Some statistics on this Smokespotter website

I just had to go into the "back" of the website to check on something and noticed the stats counter for the site.

This Helidon Hills Smokespotters website has been online for just over 18 months (since September 2012).  In that time there have been 4,509 hits on the site - not bad considering that this is a site serving a relatively small area - maybe 350 square kilometres - with a very low population level (due to the fact that around 9,000 ha is National Park and the remainder is largely rugged country with relatively large properties).

Clearly the site serves a need, but more than that, it shows that the Smokespotter Group serves a need within the larger community.

Personally I think that another statistic is worth mentioning.  Over the last 12 months there have been very few reports of smoke in the Helidon Hills.  This period includes one of the driest winters and early summers on record, with very high fire danger levels - and during that period there were only a few smoke sightings reported, and these were either outside our area or were of very short duration suggesting a permitted (or at least closely controlled) burn.  I think there were probably two reasons for this - first, the community in general took the fire risk very seriously and, second, the presence and effectiveness of the Smokespotter Group have become more widely known and this may have deterred some who could previously have risked burning off on the assumption that they would never get caught.