Tag Archives: wind

A Bushfire A.B.C

I wasn’t going to write a bushfire post this year [2019] because I thought there was no need, not with the devastating fires in NSW and QLD to focus everyone’s thoughts. But I’ve just been on Twitter and seen some of the misconceptions about bushfires.

So…here are some basics:

Fire needs just two things to burn: fuel and oxygen. However the size of that fire depends on many things:

  • Dry fuel – makes a fire burn harder and faster. Fuel is made of up dry grass, leaves, small twigs and fallen branches that build up on the ground over time.
  • Low humidity – i.e. moisture in the air and soil – makes a fire burn harder and faster.
  • Strong winds – provide the oxygen to make a fire burn harder and faster. They also transport embers ahead of the main fire.
  • Embers – land on dry fuel and start spot fires.
  • Spot fires act like pre-ignition for the main fire.

So far, these conditions could apply to any fire, in any country of the world. In Australia though, things are a little different. As well as all of the above, we also have to contend with native vegetation that evolved with fire. Some native plants developed ways to keep the species going after a fire. In fact, the seeds of many of our natives need fire to germinate.

In a nutshell, most Australian natives evolved to burn. This includes gum trees [eucalypts].

  • Gum leaves contain eucalyptus oils.
  • When these oils heat up enough, they turn into a volatile gas.
  • Add a spark and this gas goes ‘boom’. It’s an accelerant – like throwing petrol onto a camp fire.
  • Lightning strikes from ‘dry storms’ provide the spark that starts hundreds of fires every year.

So let’s look at a couple of what-ifs. Let’s say a lightning strike starts a fire. If the humidity is high and the fuel is wet – e.g. winter – the fire doesn’t go very far.

But this is what happens in summer:

  • Lightning [or human stupidity via an angle grinder creating a spark, an over-heated car starting to burn, a camp-fire left unattended, blah blah blah] starts a fire in grassland.
  • The grass fire spreads into scrub land.
  • The scrub land fire spreads into native forest.
  • The scrub at the base of the gum trees burns hotter and hotter.
  • The eucalyptus oil in the gum leaves heats up.
  • The volatile oil in the gum leaves becomes a gas and suddenly the whole tree is on fire.
  • As more and more trees burn, and the wind pushes the embers and superheated air ahead of it, the conditions for a ‘crown fire’ emerge.

A crown fire is when the fire jumps from tree top to tree top. This is a fire that nothing can stop – no amount of water bombers, no amount of fire fighters, no amount of chemical retardants. In fact, water bombers can’t even get near this kind of fire because it creates its own weather, crazy weather that makes flying virtually impossible.

In 2009, south eastern Australia was in the grip of the Millenium drought and an El Nino weather event. For those who don’t know, during an El Nino period, south eastern Australia goes through an extended ‘dry’ spell with much less rain than normal.

In February 2009, an extended heatwave of 40+ degree temperatures, extremely low humidity, high fuel loads and a ferocious north wind [bringing even more heat from the Centre] combined to create Black Saturday, the worst bushfire event in modern Australian history. 173 people died.

Now, ten short years later, NSW is likely to have another perfect storm of fire conditions…tomorrow…at the very beginning of summer…with the worst of the fire season still to come.

I’ll be honest, I’m scared. Conditions here in Victoria are cool and wet, for now, but the worst is yet to come. How will Warrandyte fare once the grass browns off and the damp fuel load turns into dry kindling? And even if we squeak through this fire season, what about next year and the one after that?

Some years ago I attend a Climate Change rally in Melbourne, and one of the speakers [from the CFA*] said something I’ll never forget. He said words to the effect that there are no climate change deniers at the end of a fire hose.

Climate Change is not causing bushfires, it’s making them bigger and more frequent. Exactly as the climate scientists predict.

Climate Change is also extending the length of the fire season. When I was a kid, January and February were the bad months. In years to come, fire season may extend from the beginning of Spring [September] through to the end of Autumn [May].

Three people have died in NSW already. How many more have to die before we stop ‘praying’ and start doing something useful?

I hope with all my heart that the legacy of Black Saturday means that Victorians remember how helpless we all felt, and act accordingly. We’ve been there. We know. The only thing we can control, even a little, is the fuel load. Reducing the fuel load won’t stop a fire from starting, and it won’t stop a fire from spreading, but it may reduce the severity of that fire by stopping it from becoming a crown fire. Harm reduction. The life it saves could be your own.

And Warrandyte? If you haven’t cleared your block yet, what the effing hell are you waiting for? NSW and QLD may be the canaries in the coal mine this year, but make no mistake, we’re in that bloody coal mine too.

To EllaD and the GO in Taylors Arms – stay safe.

Meeks

*CFA – Country Fire Authority, the volunteer fire fighting organisation in Victoria.

 

 


Melbourne – wind direction

Just checked the VicEmergency website and took this screenshot of the wind-direction[s] around Melbourne at the moment:

The little arrows indicate where the wind is coming from, and where it’s going to. The bottom of the picture is ‘south’ so you can see that in the lavender coloured areas down the bottom, wind direction is a steady ‘south easterly’ – i.e. coming from the south and east. In the pale areas, however, the wind is all over the place. Literally.

Why bother with wind direction?

Because you need to know whether a bushfire is being blown towards you or away from you.

To see the wind direction overlay on the VicEmergency map, click the Filter option as shown:

This will open a drop down list. Scroll down the list and click ‘wind direction’. This will display the lavender map at the top of this post.

To get rid of the wind direction overlay, open the Filter menu again and select ‘None’.

If you’re looking at the VicEmergency app on your phone, you have to tap your watch zone first. Once it opens, the Filter option is located up the top on the right-hand side of the screen [next to the ?].

Tap Filter and select the option for wind direction as for the website.

Given how dry and horrible this Spring has been, I think I’ll be keeping that wind direction overlay on at all times.

Stay safe,

Meeks


Micro-grid for Kalbarri in Western Australia!

As exciting as Elon Musk’s bet, and subsequent giant battery may be, there is a hell of a lot more going on in Australia that never gets a mention. Not sexy enough I suppose. Well, I think micro grids, renewables and batteries are very sexy so have a look at this:

This is the proposed plan for a micro grid in Kalibarri, WA. Kalibarri is a rural community which relies on power coming in via the Geraldton Feeder. Just one single source of power. When that power goes down, Kalibarri goes dark. Kind of hard to run homes, not to mention businesses, without power.

But all that will be a thing of the past once the micro grid is up and running. It will include power from the windfarm as well as power contributed by individual homes running solar panels. All that power will charge a 2 MWH [megawatt hour] battery, and the Geraldton Feeder will be there as well. All that equates to power security for a community that has had anything but. On a national level, the Kalibarri micro grid is also an example of what Australia can do in spite of the idiots in Canberra.

You can read the whole story here:

https://westernpower.com.au/about/media/contract-awarded-for-kalbarri-s-renewable-microgrid/

And now a big thank you to Dawn who found out about this development and sent me the URL. Dawn is a Silversmith who loves cheering people up. She would call this a cheeryuppy story and I couldn’t agree more!

Keep smiling, only four more days ’till the weekend. 😀

Meeks


Dear Mr Turnbull – India is leaving us behind

Originally posted on Climate Denial Crock of the Week: India charging ahead on renewables. Vying with China for global leadership in the growth industry of the new century. Meanwhile, Washington looks longingly to the 19th century. Watch for new video on this topic coming very soon. Meanwhile, Denmark has decided to offload oil interests, and…

via As US Dithers, World Charges Ahead to Renewables — Die Erste Eslarner Zeitung – Aus und über Eslarn, sowie die bayerisch-tschechische Region!

India is surging ahead with renewables because the India government recognizes that renewables will be cheaper in the long run than fossil fuels. China is doing the same, and both countries are positioned to become the power houses of industry in the coming decades.

But where does that leave Australia? Fumbling in the dark, that’s where. We could have become world leaders in solar technology, but the lack of political vision and will sent our innovative companies offshore, and now we import the technology from…China.

All that potential, wasted, because our politicians are ‘scared’ of upsetting the apple cart. So instead of leading, we follow, and in the process, we get left further and further behind.

Ten years ago, the Australia people voted with their wallets when they installed record numbers of rooftop solar panels. But instead of rewarding us, successive governments have tried to slow or stop small scale solar altogether.

And then there’s Adani…taxpayer dollars to fund the hope of short term gain. Pathetic.

Meeks


Food #gardening in mini greenhouses

The weather here in Melbourne is bleak and blustery, but we had a few minutes of sunshine earlier on so I raced out with my trusty phone to take these:

The pictures show the mini greenhouses I bought from Bunnings. They come in a flat pack -shiver- but everything fits together quite easily for a change, including the clear plastic ‘cover’ that fits over the frame. The covers go all the way to the floor [but do not ‘seal’ completely]. Access to the inside is via heavy duty zips.

I was skeptical, at first, but I quickly noticed that the interior of the greenhouses is noticeably warmer than the outside air, and visibility is usually low due to condensation on the plastic. I’m not sure how the plants will go in summer conditions, but at the moment I’m only watering a tiny bit, once every 2 weeks or so.

Wind is a bit of a problem here, but by positioning the mini greenhouses up against the wall, and anchoring them with big, earth filled ‘tubs’ [see below], both structures have survived the north winds we get up here, so far at least.

I don’t usually do product endorsements, but I liked the first mini greenhouse so much, I went back and bought a second one. The original contains some very happy lettuce and continental parsley while the new one contains BokChoy [?] also grown from seed.

If anyone is interested in growing some winter vegetables, here are the salient facts:

Position:

North facing deck, up against the brick wall of the house for both extra warmth and protection from the wind.

Supplier:

Bunnings in Eltham

Form:

Flat pack. No issues with putting it together.

Cost:

I think each mini greenhouse was around $29, so they were very cheap.

Tubs:

I found some ordinary, plastic storage tubs, the kind you can buy at the supermarket, and drilled holes through the bottom of each one. Then I placed the tubs on top of their own lids to catch excess water and provide a ‘well’ of water to draw on.

Cost:

The tubs were on special and again, at roughly $10 per tub, they were much cheaper than an equivalent plant pot. Another important point was that they fit very neatly inside the bottom of each mini greenhouse, thereby acting as a kind of ‘anchor’ against the wind.

I know the tubs won’t last for very long because of the UV etc, but when they disintegrate, I’ll simply buy new ones. In the meantime, I have lovely, lush lettuce almost ready to harvest and some Chinese vegetables coming on. Colour me happy. 😀

cheers

Meeks


Warrandyte swelters… and we all hold our breaths

Temperatures of 41 C [105.8 F] are forecast for today, with strong northwesterly winds pushing south before a cool change tonight.

What does all that mean for us? Very, very high fire danger, that’s what.

As always, it’s the northerly wind that turns an unpleasant day into a dangerous one. Add a dry summer to the mix, and the potential for lightning strikes, and suddenly a dangerous day can quickly become fatal.

Here, in Australia, we are told we are responsible for our own safety during bushfires. We are not forced to evacuate, which can be a good thing if, like me, you have systems in place to protect yourself if all else fails. Unfortunately, not many people are prepared to spend their hard earned cash on fire fighting equipment they may never use.

Those people often say they will leave if a bushfire threatens, but few have any idea of when they should leave. Most stay at home, monitoring the situation and doing a ‘wait and see’.

I can sympathize with that very human reaction. None of us want to leave unless we really have to. Where will we go? What will we do with the animals? The kids? Elderly parents? And beneath it all is something we all know but avoid facing – if we leave, will we have anything to come home to?

That human response is the elephant in the room, and the fatal flaw in the current bushfire strategies. It may give the authorities a legal ‘out’ should something go pear shaped, but it’s of little use to actual residents.

So in case you’re reading this, here are some facts :

The time to leave is either the night before a bad day, or early in the morning – i.e. before there is any danger.

Why? Because once a bushfire does threaten your area, being on the roads is the WORST place to be.

Why?

– Because smoke can make it almost impossible to see where you’re going,

– Because trees can fall across the road, trapping you in your car,

– Because other drivers will be panicking just as much as you, and they can run into you, leaving you both stuck with no shelter.

Or, if you live in a place like Warrandyte, you might find yourself in an almighty traffic jam as every man and his dog tries to cross the bridge over the Yarra at exactly the same time.

If you have ever tried to cross the bridge during peak hour, you will know exactly what I’m talking about. People caught in such a traffic jam would be …in a bad way if the fire came through over the top of them.

So if you are caught unprepared, you are more likely to survive in your house than in your car. In a house, you have a bigger ‘bubble’ around you. In a house, you have multiple points of exit if the house itself begins to burn. In a house, you at least have some chance of getting out in one piece.

But here is where human nature strikes again. Knowing something is not the same as feeling it. You may know that you are safer staying in your house, but will you be able to resist the urge to run? Especially when you know you’ve done nothing, absolutely nothing to make that house less fire prone?

Fear is pernicious, and few of us are immune to it. So if you know you’re not prepared, please don’t wait. Go now. The worst that can happen is that you’ll lose your house, or feel a bit silly when nothing happens. But at least you and the most precious things in your life will still be alive to start again.

stay safe and cool,

Meeks

 

 

 

 


Bushfire danger – burning off on high wind days

Courtesy Shannon Buxton

Courtesy Shannon Buxton

Despite countless examples of bushfires triggered by controlled burns gone wrong – set by professionals, mind you – some dick donkey is burning off today. I can see the smoke rising up through the trees across the valley from my house.

It’s not hot, yet, but there’s a strong north-easterly blowing, and wind is the element that turns an ordinary bushfire into a potential inferno.

Burning off on a windy day is just asking for trouble. Gum leaves burn even when they’re fresh and green.

Unfortunately, today hasn’t been declared a day of Total Fire Ban, so there’s not much I can do about Donkey-Boy across the valley. All I can do is sit, rant, and hope he’s standing next to that fire with a garden hose at the ready.

The thing that worries me most, though, is that Donkey-Boy probably thinks he’s doing the ‘right’ thing. He probably works all week, and only has the weekend for chores, including fire prevention chores. He probably had other chores to do yesterday, when it was warm but windless. So today he’s catching up. Yay.

I don’t know exactly which house belongs to Donkey-Boy because there is a sea of trees between my house and his, but I know the general position. Up on that hillside are a number of brand new houses. I can only assume the residents are also new to Warrandyte. Clearly they know enough to clear up the fuel load on their properties, but they don’t know enough to know when it’s safe to do so.

To be fair, it did rain heavily two days ago, so the chance of a fire going out of control is minimal, but you’d be amazed at how quickly things can dry out in Warrandyte. One day the ground is soft and moist, the next you can hear gum leaves crackling underfoot. The reason is the lack of deep topsoil and the steep terrain. Rain tends to run off before it has a chance to soak deep into the clay subsoil. Ergo, things dry out, fast.

And we have a mono-culture of red box gums.

Let me tell you a story about gums. This story was told to me by my whippersnipper man*. He was working up in the foothills of the Dandenongs a couple of years ago, and he was burning off on a day similar to this one. It was windy and embers floated up in the air. Nothing caught fire at ground level though.

Once the fire was out, my whippersnipper man made sure the coals were safe, packed up and went home. An hour later he received a panicked call from his client : one of the gums was smoking. He raced back and was just in time to stop the whole canopy from going up in flames.

“What on earth happened?” I asked, half wondering if he was pulling my leg. He wasn’t.

Apparently an ember had floated up into the gum tree, landed in a fork and smouldered until it had enough oomph to burn.True story.

So the moral of this post is to do your homework, and not do burning off on windy days.

And in case you’re wondering, there’s still a bit of smoke curling up above the trees, but the wind has died down, and there are rain clouds coming in. Looks like neither Donkey-Boy nor I will have to put our fire plans into action today, for which I am truly thankful.

cheers

Meeks

* For my northern hemisphere friends, whippersnipper = brushcutter.


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