Thread by @callapilla

The #BushfireRC is back on for the next few days, focusing on hazard reduction burns.

There are ELEVEN witnesses listed for today. They'll appear in panels.

On the list are: Emma Campbell and Dr Steve Read from the federal agriculture department; Associate professor Kevin Tolhurst from Uni Melb, Prof Ross Bradstock from Wollongong uni, Prof David Bowman from Uni Tas...

... then @FFMVic_Chief, CFA deputy chief bushfire officer Alen Slijepcevic, NPWS exec director Mike Williams, Brett Loughlin from the CFS, QFES deputy commissioner Michael Wassing, and Queensland parks and wildlife service exec director Leigh Harris.

The royal commission hearing has begun. Senior counsel assisting Dominique Hogan-Doran runs through the issues that will be examined in the hazard reduction block. Including the effect of grazing.

(If we go back to cattle in the high country over this I will throw something.)

Hogan-Doran says the evidence suggests the majority of property loss occurs in weather-dominated fires, when the FDI is over 50. But when conditions ease, mitigation measures like fuel reduction are more important.

"Even at the extreme, if there is no fuel there can be no fire."

The RC has received 1,735 submissions since 2 March, and yesterday it published 1,000 of them on its website.

1,302 of those submissions were from individuals, 48% of whom reported being affected by the 2019-2020 bushfire season. 45% lived in a bushfire affected area, 22% evacuated, 7% were firefighters, 22% suffered a personal or financial loss.

The commission has to date received 98 responses to notices to produce documents, 214 responses to requests for information.

So far, that totals 26,257 documents, with a combined more than 300,000 pages.

Here's a map showing where the submissions were received from.

Syntax, what is it.

Alright. First witnesses up are Emma Campbell, acting first assistant secretary in the federal department of agriculture, water, and environment, and Dr Steve Read, assistant secretary of same.

Leading this evidence is counsel assisting Jesmini Ambikapathy.

She asks Read to describe the purpose of the state of the forest report 2018.

He says the purpose of the report is to describe the state of the forest.

Read says in the 2019-2020 bushfires in southeastern Australia, 10.3m hectares were burned of which 8.5m ha was forest. So, that's 82% of the burned area.

No distinction drawn in this question between public and private forests — Q just seems to be forested areas vs not.

Here's a map of all forested areas in Australia from the 2018 state of the forest report. Pink bits are commercial plantation, green are native forests.

A good time to remind followers that this thread is a combo of reporting and commentary on the #bushfireRC so if I say something like "man Australia really does have fuck all trees" that's me speaking, not anyone in the royal commission.

Read says forest in Australia is defined as trees upwards of 2m with crown cover of at least 20%.

Closed forest - rainforest, cool climate rainforest
Woodland forest - 20-50% crown cover
Open forest - regular eucalyptus forest

All these maps are available on the ABARES website.

This next map breaks down forests by their main species type, and the scale is down to 1ha.

This map is forest by tenure.

Purple is private forest, yellow is other crown land, blue is leasehold, light green is multiple use public forest (state forest), green is nature conservation reserve.

Private forest here is just forest on land held by private tenure.

And this is a map of the Indigenous forest estate. Maroon is Indigenous owned and managed, blue is Indigenous managed, green is Indigenous co-managed, yellow is other special rights.

This is forest area by number of fires, 2011-12 to 2015-16.

Darker colour = more fires.

You'll see that northern Australia burns HEAPS more frequently.

Read says it takes TWELVE TO EIGHTEEN MONTHS to get fire data from states and territories to make that fire map.

That is.... clearly too long.

He says it takes that long because they are combining multiple data sources to get the highest possible level of accuracy.

Which is good. BUT SO SLOW.

Ok. So this map is forest burns from 2011-12 to 2015-16 by planned or unplanned. Brown is both planned and unplanned, orange is unplanned, yellow is planned.

Read clearly knows his subject very well and is, ah, keen to show that knowledge.

(You have got 11 witnesses today how are you getting through this)

A bar chart.

Back after the morning break. We've got Associate professor Kevin Tolhurst, Professor Rod Bradstock and Professor David Bowman.

Bowman says the key factors that determine the behaviour of fire are the availability of fuel and an ignition.

In the most simplistic sense: more available fuel equals a more intense fire.

Tolhurst is describing different layers of fuel. Each different kind of fuel behaves a different way, so the different layers of fuel are used to predict fire behaviour.

Layers are surface fuel, near surface, elevated, bark fuel, canopy.

The bigger the fire, the more layers are involved. And it works upward: cool burn fires are surface and near surface only; big bushfires go into the canopy.

He's also describing coarse vs fine fuels. Coarse fuels are anything bigger than 6mm in diameter.

Tolhurst says woody material takes longer to ignite but has "an enormous amount of stored chemical energy... then all of that heat is contributing to the plume rise and how high the plume gets".

The hotter the fuel the higher the plume, the higher the plume the hotter the fire.

A high smoke plume draws in wind, often drier, stronger wind from high in the atmosphere.

"We can get strong fire induced winds, the winds can be as strong as cyclones effectively, so the fire starts to create some of its own local weather conditions".

Fuel is considered more flamable if it's very fine (i.e. dry grasses), has strong horizontal and vertical integrity (so the fire can climb up the trees; like when fire goes up a slope) and just the general mass of fuel.

Bradstock says the aim of hazard reduction is to "ameliorate the behaviour of a subsequent unplanned fire through not only reducing the mass or loading of fuel, but also tinkering with those discontinuities (by interrupting the vertical to horizontal integrity of fuel).

Tolhurst says "it's not the fuel that's the hazard per se."

You're trying to reduce the amount of radiation, embers, and convective heat generated.

"Sometimes the fuel is considered a hazard but unless the fuel is actually burning it's not a hazard."

Bowman says there is a risk that by modifying an environment by doing fuel reduction you could create a "wrong feedback" and create a "perverse outcome."

Bowman: "Inappropriate management could drive a system to become more combustible because for instance there is more fine fuel mass such as grass... All things in ecology have feedbacks, that's why fire management is so complicated because it's not simply turning off switches."

Bradstock says one of the primary motivations for fuel reduction is to "increase the potential for active suppression of the fire".

A secondary consideration is by reducing the rate of spread of fires. Different management may be used for each.

Tolhurst: you need to make an assessment on the value of hazard reduction across a landscape and across a long period of time. "So often the assessment of the effectiveness of hazard reduction... will be assessed more or less as an immediate impact."

He adds that "some burning practices may be counterproductive in the longer term because they've changed the structure or the species composition of the site."

He says the objectives should be based on the broader landscape - at least a river catchment area, about 100,000ha.

Tolhurst: "And we need to be talking about a longer time frame, so we might need to be talking about say a 30 year time frame not just what might be in the plan for five years. We need to be looking at the longer term implications of the hazard reduction."

"It's not just an operation to be viewed on a 12 monthly basis, or even a three to five year basis."

Bowman says one of the reasons for wanting to change fire behaviour through fuel management is it makes it slightly easier to predict what it's likely to do.

If it gets into the atmosphere, the fire becomes "dominant" in the landscape.

Bowman: "It's creating its own wether systems, its own behaviours, and those situations are outside the capacity of science to really predict. They're very scary."

Bowman says pyrocumulonimbus events were considered "bushfire oddities" before this season. They only really know of one in Tasmania, for example, the 2013 Dunalley fires.

"Unfortunately this last summer... there was a near doubling of the record of these events."

Bowman: "Something happened this last summer which is truly extraordinary because what we would call statistically a black swan event, we saw a flock of black swans. That just shouldn't have happened."

Tolhurst worked on the Phoenix Rapid Fire prediction model that he says "actually model these fires quite well."

The phonenix model was within 9% of the spread of the Dunalley fire.

He says firestorms can be well predicted provided the imputs are put in correctly.

Tolhurst said the issue isn't the predictive tools, but firefighter training.

"A lot of the training that we do for firefighters still talks about surface fuels and watch out for pyro convective activity. Well, we can do much more than watch out for pyro convective activity."

Bowman disagrees that you can actually predict where they are going to happen.

"The idea of pinpointing these events is not true, and importantly fire behaviour models break down when they're confronted by these events" because they generate their own weather.

Bowman says more work should be done to learn from/analyse case studies like Dunalley so people actually understand the modelling.

Tolhurst says the benefits of fuel reduction burns diminish over time, and when you get to 10-11 years there's very little difference.

Tolhurst: "In five, 10 years time you may actually end up with a worse fuel arrangements if the way in which the regeneration occurs brings back more flammable species or a greater level of continuity. So you may have had a short-term gain for a long-term loss."

Bowman says some landscapes are not amenable to prescribed burning because they have the wrong fuel structure or fuel type. That often includes tall wet forests, even though in dangerous fire weather they can burn "terribly intensely".

"There are different vegetation types that you simply can't burn safely".

Tall wet forests are a particular issue, because they either don't burn at all, or they dry out and they burn in such a way as to be too dangerous for a prescribed burn.

Bradstock says that the worse the fire conditions, the less effective the fuel reduction.

In catastrophic conditions - something has to have been burned a year before for that fuel reduction to have a chance of slowing the fire. In more benign wether, it's 5-10 years.

Tolhurst says that prescribed burning decisions have to be assessed at a landscape level, "and I don't think we do that very well".

In the 2003 Vic fires, he says, prescribed burns were effective in changing the pattern of the fire in the landscape but not reducing the size.

That's alluding toward steering fire away from certain critical areas.

Bowman says "we should be treating all our fuel management approaches as giant experiments that we're still evaluating. We certainly don't have the answers."

But he says there are some case studies showing the benefit of some "fuel treatments".

He says that the effectiveness is based on the landscape and the environment - what works in a tropical savanna will not work in a forest in Tasmania.

"So this is one of the challenges for a national perspective. It's heavily contingent on where you are."

Bradstock says its' possible to examine the direct relationship between (hazard reduction) treatment patterns and practices and actual asset loss. "And there are examples of that in the literature."

Bradstock seems to have a slightly different opinion to Tolhurst and Bowman.

Bowman says you get a "much better benefit if you concentrate your fuel management around where your assets are".

Except doing that is more expensive that shooting blaze balls out of helicopters to clear large areas.

He says there needs to be an economic assessment too.

Bowman says there needs to be a "hard nosed economic analysis, where we look at the trade-offs and we have a... clearly stated budget, and that the government can't be expected to have an infinite budget."

"What happens in an emergency fire fighting modality is the behaviour... the resources are unlimited for the emergency. We have to move away from that to say that we're trying to optimise within available resources for fuel management."

Tolhurst says that asset protection burns are effective but they don't deal with the enviro cost of "the scale the fires that can get to in the back country."

"We have to deal with this increasing occurrence of those large landscape-scale fires in terms of the impact they have. We can't just put up a small barrier."

"Part of the climate change scenario is that there's going to be more fire in the landscape because there's more fuel in the landscape with the changing vegetation as a result of reduced rainfall and higher temps. Fire has to be part of this solution cross the broader landscape."

Commissioner MacIntosh says one of the objectives of fuel reduction is to facilitate suppression and improve the effectiveness of other mitigation measures like building regulations.

Everyone agrees.

He says another objective is to reduce the spread/severity to protect and conserve enviro values.

Bradhurst says that some biota are sensitive to fires, like koalas, "but there are other biota which are quite complicated with higher intensity fires".

Bradstock says that fuel reduction close to built assets is "more expensive than treating areas further away in the landscape. However despite that expense, it is more cost effective in terms of risk reduction."

BUT, Bowman adds, there's a greater smoke hazard.

Tolhurst says prescrined burning should not just be done to protect human life and property, it should also be done to protect other things "we value" (aka koalas).

Tolhurst: "I think there's strong evidence to suggest that we need more fire in the landscape and one of the paradoxes of effective fire suppression is that we're removing wildfires from the landscape.. that almost puts an onus on us then to replace those wild fires."

He is arguing that by suppressing naturally occurring fires, such as by lightning, "we're reducing the amount of fire in the landscape until we get these catastrophic events like we have just seen, and the impact then is horrendous."

Bowman suggests that it would be possible to allow some naturally-ignited fires to burn if they are "understood to be safe enough to allow to burn".

Bradstock disagrees with the suggestion that all naturally-occurring fires are put out. He gives the example of the fire this summer in the Wollemi National Park, "possibly the largest forest fire in recorded history".

It wasn't put out.

He also says that firefighting agencies have a mandated responsibility to protect life and property.

"When you've got limited budgets and limited opportunities, people will be brutally exposed if they do not prioritise treatments in a cost-effective way to mitigate risk"

Bowman said the interaction between fire and drought can cause the landscape to change "because the capacity for the landscapes to support the current vegetation is not going to be possible under the emerging climate".

We're starting to see that in the Alps, with the snowgums.

Bowman says it's the "vegetation equivalent of an ice sheet breaking up as the climate is becoming more fire prone, drier, the old vegetation types are going to not just slowly change and migrate, but be burned up. This is a very concerning idea."

Tolhurst goes back to the ability to control fires. 99% of fires in Vic are now kept below 10ha, but 20 years ago, only 95% of fires were kept below 10ha.

And that's the lunch break.

There are six witnesses to hear from after lunch. Resuming 2.15pm.

Alright, we're back.

Bunch of witnesses up now. It's @FFMVic_Chief, CFA deputy chief officer Alen Slijepcevic, Mike Williams from National Parks and Wildlife, Brett Loughlin from the SA CFS, Michael Wassing from QFES, and Leigh Harris from QPWS.

If you're playing along at home: that's the remaining 6 witnesses on the list for today.

Counsel assisting Andrew Tokley is leading the evidence this afternoon.

I don't have any favourites among the many counsels assisting, except for Dominique Hogan-Doran because she follows me on twitter. (Hi, @DHoganDoranSC!)

Anyway. Michael Wassing, the deputy commissioner of QFES, has been talking.

Toking is asking everyone to provide an overview of the "objectives and priorities of bushfire hazard reduction activities" undertaken in their various jurisdictions.

Wassing says the priorities are the protection of life, property and the environment. In that order, I presume.

Wassing says they often have hazard reduction objectives that are not able to be achieved, so they carry "residual risk, if you will, into our operational setting."

For example hazard reduction burning may not be carried out because the fuel is needed for agricultural purposes.

We've taken a deep-dive into public servant speech.

.@FFMVic_Chief says Victoria was the "first jurisdiction in the world to link our fuel management program to an outcome of risk."

That is, linking it to a risk to life not just the number of hectares.

Hardman says they have a risk target of 70% of the maximum possible bushfire risk. That target aims to reduce the impact of fire in the landscape by almost a third.

They calculate bushfire risk using computer modelling, mainly the phoenix rapid fire modelling system. They simulate 11,500 fires across all of Victoria, and 40km over the border into NSW and SA.

He says fuel management is just one form of risk mitigation.

Once they do the risk assessment they consult with the CFA, other emergency service partners, and key groups like tourism, vignerons, beekeepers etc that are affected by smoke.

That all becomes a regional strategic bushfire management plan, which are redone every 5 years.

Slijepcevic, who has an excellent accent, says the strategic objective of all bushfire activities in Victoria is to "reduce the impact and consequences of bushfires on human lives, on communities, essential and community infrastructure, the economy and his environment."

"The principle around the protection of human life, which includes the lives of all community members and emergency services personnel, takes priority over all other considerations in bushfire management."

I am probably not going to exhaustively tweet the responses to these questions because they're all quite similar.

Brett Loughlin from the CFS says that in addition to protecting life and property, in South Australia they have identified 80,000 environmental assets for protection.

Chief commissioner Mark Binskin asks if there are competing priorities for assets — if there's a reducing window for prescribed burns, etc — who makes the call on what gets saved?

Wassing says the risk "can be escalated."

Binskin askes Wassing if the community is told what the residual risk is at the start of the season.

Wassing says residual risk is "considered in operational planning" and informs local area plans, so the community is told in that way.

Binskin asks Hardman how Vic communicates residual risk at the start of the fire season.

Hardman says they produce an annual fuel management report, which breaks the risk down into each region.

Binskin points Hardman to the Safer Together pamphlet from 2015, which has this map breaking down the bushfire risk landscape.

(I don't really understand what these risks are a percentage of?)

The statewide aim is 70%. Binskin asks if there were any regions were they could not get the residual risk to 70% or below.

Hardman says that the residual risk in peri-urban forested areas like the Dandenongs may by higher, around 80%. The STATEWIDE AGGREGATE target is 70%.

Same Q to SA.

Loughlan says all the bushfire management area plans are publicly available through the CFS website, and you can zoom down to see the risk rating for individual properties.

He says they don't lower risk ratings, so don't publish residual risk.

Loughlan: "There is always going to be levels or residual risk to assets... there is every chance that under the wrong type of weather conditions... those [hazard reduction] treatments may not provide a level of effectiveness."

That is "to acknowledge always going to be a level of residual risk in assets that are identified has being at risk... it highlights to the community that in those areas there is a real importance in individual property protection and planning."

Binskin: How do you then state the outcomes of your hazard reduction activities?

Loughlan: we report to the community on activities that are undertaken but are clear to tell people that just because a hazard reduction burn has been undertaken it doesn't mean there's no risk.s

Loughlan: "If we use that last example of an asset protection zone mechanically maintained along a row of homes (read: mowing) whilst that might reduce direct flame contact, those assets are still at risk from ember impact."

Commissioner Bennett is very interested in predictive modelling. She asks Victoria if they did any simulations that predicted the 2019-20 bushfires.

Hardman says once a fire is ignited, they use their modelling to predict the worst case scenario and based firefighting on that.

Hardman says the 11,500 bushfire simulations they do in a 5km grid across Victoria is based on the "worst case scenario" in an FDI of 130, which is Black Saturday conditions.

It means they have a "really good idea...exactly where our risk profiles will be".

"We had this extreme underlying dryness, the fuel moisture was around 1% in the top 1m of soil. That meant heavy fuels would be available to burn... we knew we were going to have really dramatic fire behaviour. We were very well prepared for the extent and severity of the fires."

Tokely is now asking all states to outline their hazard reduction activities and methods.

Gremlins in the feed. We've lost contact.

The feed has been back for a little bit now.

They are talking about reducing roadside vegetation. Namely, whose responsibility it is.

Apparently the answer is "it depends".

Tokley now asks all states if having national coordination and information-sharing would help them plan and manage bushfire mitigation.

SA up first. They say that the data used to plan bushfires is held by the states.

Loughlin said they are "seriously concerned" about the changing climate. The 2019-2020 summer saw SA record five separate catastrophic bushfire days - that's a record.

He said they're facing "less opportunities for prescribed burnings and more frequent fire weather days."

Loughlin says that according ot UN climate modelling the number of extreme or catastrophic fire danger days in the Mount Lofty Ranges could go from 26 per year to nearly 40 by 2070.

That is a lot! But also 26 now is a lot a lot.

Slijepcevic says that Victoria believes there should be a long term national bushfire science strategy that focuses on the way bushfires behave and the impact on communities, critical infrastructure, etc.

That would include the impact of climate change.

He said there should also be national collaboration on bushfire simulators, esp. making sure they're couple with atmosphere simulators because "over the last couple of years, most of the fires that caused damage in Victoria were really... atmosphere driven events."

Victoria would also like to see more investment in improving the Australian fire danger rating system, landscape dryness modelling, fuel availability monitoring, etc.

They said they have a good relationship with BOM but it would be good for BOM to further develop its systems.

The current FDI model used by BOM was developed in conjunction with DELWP in Victoria so they're having to modify it as they roll it out nationally.

Geoscience Australia could help by managing national datasets, to improve vegetation monitoring.

Hardman says the residual risk score used in Victoria is focused on house loss - it shows the potential loss of houses in he fire footprint. They use that as a proxy for loss of life.

SA doesn't have that kind of modelling, it provides a qualitative assessment of different risk processes. They're currently trialling using more simulations in their mitigation planning.

QLD uses the phoenix, sabre and catalyst systems for "seasonal outlook prognosis" and for producing a six of 7 day outlook during the season, to inform operations.

Decision making is a mix of predictive modelling and qualitative assessments and local knowledge, Harris says.

And that's it until 10am tomorrow.

Eleven more witnesses on the list for then, more state enviro department/firefighting agency people. Full list here: naturaldisaster.royalcommission.gov.au/news-and-media…