Aussie Bush Fires
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@antipodean said in Aussie Bush Fires:
Looks like the Blue Mountains are done for. Gospers is currently out of control and tending towards Kurrajong Heights. The topography will have it roar up the valley and Thursday's forecast is looking dim. Maximum of 43 and winds northwesterly 25 to 40 km/h in the morning. So likely to jump the road and burn unabated until it gets to Warragamba Dam.
All the main towns along the Great Western Highway could be affected.
Not quite done for then, Antipodean, or now.
Daughter No 2 is on the western edge of Katoomba about 1.5 kilometres from the Carrington Hotel (where my son in law managed the bottle shop for 5 or 6 years) and about 1 kilometre north of Cliff Drive near the Three Sisters. Cliff Drive is the northern edge of the Megalong Valley "Ruined Castle fire", she sits above Megalong Creek Valley offshoot. The fire front hasn't got to the ridges there yet.
The Rural Fire Brigade people have the current situation as "The fire has burnt over 9,000 hectares and is being controlled." The Blue Mountains is subject to serious fires each summer, this year is a belter, but the fire blokes have been all over it all my life. The media would do well to wind down the hysteria a good bit - every year it is supposedly unprecedented, longer, faster, higher, more threatening, saturated in cholesterol and exhibiting ADHD.
They have been on "be ready to leave pronto" footing for several weeks now. That means everyone close by all the time, a bag of valuables at the door, and a fast exit east to the CBD main street (concrete and bitumen sanctuary). They cannot contemplate a long distance dash down the Great Western Highway in either direction because it can be closed within minutes if the wind blows in the wrong direction momentarily. They tell me they would be flat out seeing 50 yards ahead anyway.
The family takes it all in their stride (two boys 20 and 17, my grandaughter 15). My daughter works in Katoomba and has a role manning central fire communications through this period. My son, the other two girls and I do a morning ring around each day and I pray for easing of the threat.
I spotted a photo in their local Rural Fire Service collection - several 30 something blokes looking serious and a water truck, could easily be Silver Ferners. Their names are noted, including Farr Gough.
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Crazy stuff, screw being caught up in that..
Australia fires: Holidaymakers flee to water as blaze hits town
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Just to bring this thread up to date a little. Today in NSW there's eight fires currently at emergency level and another
sixseven at "watch and act", all of them are out of control. We're expecting a southerly change which should push the fires to the South of Batesmans Bay towards town:
Then there's 4000 people taking shelter at the water's edge in Mallacoota:
Victoria is burning out of control to the east of Mallacoota to Bairnsdale, north to the Great Dividing Range.
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@antipodean that stuff with the tankers between the fire and the people is surreal. How some of these fireys are still upright given how long they have been fighting fires continuously is nothing short of astounding.
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@mariner4life yep, those people are true legends.
Fark those pics are just insane!!
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yeah the smoke has been drifting for weeks, creating some amazing sunsets...
Just crazy devastating shit over there though, with no respite in sight
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@NTA said in Aussie Bush Fires:
Interesting to think of the fuel load in that way - up to 50% increase in available hazard. Probably contributes to they can't do hazard reductions as often
Without wanting to detract from the actual story, the increase from 10mm diameter to 15mm is a 125% increase in volume, not 50%. So, much worse.
Honestly I don’t know how you guys over there can stand the tension of living with such a thing hanging over you. All I’ve got to worry about is my lawn might go a bit brown.
Best of luck to you all.
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@JC said in Aussie Bush Fires:
Without wanting to detract from the actual story, the increase from 10mm diameter to 15mm is a 125% increase in volume, not 50%. So, much worse.
Got me interested in the maths there.
Assume that you did this: 10mm circle has an area of 78.5 mm sq, 15mm is 176.7 mm sq, so ended up at %125 increase? Multiply by height to get volume of disc.
A 15mm tree is presumably much taller so it gets even worse in terms of volume of fuel. Not sure that girth of a tree has a direct correlation to height but they must be bigger.
Thicker trees will also burn for longer and as he says will generate more heat.
It genuinely is an escalation of the problem -maths aside - and really does suck.
My sister is in a rented apartment as the ceiling cavity in her house caught fire due to a lightning strike in that storm a couple of weeks back. Having escaped the bush fires that went and happened...
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@Snowy said in Aussie Bush Fires:
@JC said in Aussie Bush Fires:
Without wanting to detract from the actual story, the increase from 10mm diameter to 15mm is a 125% increase in volume, not 50%. So, much worse.
Got me interested in the maths there.
Assume that you did this: 10mm circle has an area of 78.5 mm sq, 15mm is 176.7 mm sq, so ended up at %125 increase? Multiply by height to get volume of disc.
A 15mm tree is presumably much taller so it gets even worse in terms of volume of fuel. Not sure that girth of a tree has a direct correlation to height but they must be bigger.
Yep.
Thicker trees will also burn for longer and as he says will generate more heat.
It genuinely is an escalation of the problem -maths aside - and really does suck.
My sister is in a rented apartment as the ceiling cavity in her house caught fire due to a lightning strike in that storm a couple of weeks back. Having escaped the bush fires that went and happened...
That’s bizarre. For me it’s easier to picture if I imagine Mother Nature wearing a big black No11 jersey and everybody else wearing white ones with No15 on the back.
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I've mentioned this before, but if people want to live amongst the forests in this country and don't want their homes destroyed, they should build them according to the relevant standard (AS 3959) :
AS 3959 divides bushfire prone areas into six bushfire attack levels (BAL), based on the severity of the building’s potential exposure to ember attack, radiant heat and direct flame contact:
- BAL-LOW - There is insufficient risk to warrant specific construction requirements.
- BAL-12.5 - Ember attack.
- BAL-19 - Increasing levels of ember attack and burning debris ignited by windborne embers, together with increasing heat flux up to 19kw/m2
- BAL-29 - Increasing levels of ember attack and burning debris ignited by windborne embers, together with increasing heat flux up to 29kw/m2
- BAL-40 - Increasing levels of ember attack and burning debris ignited by windborne embers, together with increasing heat flux up to 40kw/m2 and with the increased likelihood of exposure to flames.
- BAL-FZ - Direct exposure to flames from fire, in addition to heat flux and ember attack.
An acquaintance built a new home in the Blue Mountains and making it as fire proof as possible cost an extra $600K.
That way you hope you're unlikely to come home to this:
I expect insurance agencies will take care of this problem anyway by making it impossible unless they meet the design standard.
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@antipodean I wonder if the ratings will change based on the increased severity of the recent fires? So say a house was in a BAL-29 zone it is now a BAL-40, do people then need to continually upgrade their homes as the climate changes?
You also have to think how many thousands of homes are in these zones that were built prior to the standards or knowledge, should all of these people tear down and rebuild? It really is a tricky situation but I agree Insurance will likely dictate this moving forward.
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Interestingly I purchased the property I now live in just over a year ago. I cannot recall being asked by banks or insurance companies what standard the dwelling was or what risk level the property is. I am now feeling very naive as I am pretty close to the bush. The dwelling is steel frames and colourbond external but again I have no idea what standard it is.
I am thinking that perhaps all houses when sold should have the rating displayed and the area where the house is situated has an easy to understand risk rating.
I highly doubt most people would know to be honest.
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@chimoaus said in Aussie Bush Fires:
@antipodean I wonder if the ratings will change based on the increased severity of the recent fires? So say a house was in a BAL-29 zone it is now a BAL-40, do people then need to continually upgrade their homes as the climate changes?
You also have to think how many thousands of homes are in these zones that were built prior to the standards or knowledge, should all of these people tear down and rebuild? It really is a tricky situation but I agree Insurance will likely dictate this moving forward.
I think that it'll be two fold: Councils will dictate new builds and ultimately owners will be advised by insurance companies they won't insure unless it meets a certain standard.
Given recent commission and enquiries, politicians will step in to ensure that insurance companies can't blanket refuse existing builds, they'll just make it prohibitively expensive.
As I used to say about the Richmond - Windsor floods; live on a floodplain, buy a boat...
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@antipodean Looks like I am on the verge from BAL-40 and BAL-FZ. The house is only 5 years old so I assume it was built with that rating in mind. Guess I should probably check.
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@chimoaus said in Aussie Bush Fires:
@antipodean Looks like I am on the verge from BAL-40 and BAL-FZ. The house is only 5 years old so I assume it was built with that rating in mind. Guess I should probably check.
If nothing else, for your own peace of mind.