Transcript
WEBVTT
00:00:00.059 --> 00:00:11.131
With this result, when a fire starts with 34% chance of a dire evacuation, 34% chance of tragedy, you cannot just rely on fire suppression.
00:00:11.131 --> 00:00:12.605
That age has passed.
00:00:12.605 --> 00:00:14.627
You need to look at so much more.
00:00:14.627 --> 00:00:19.033
You need to look at community resilience, you need to look at the fuel condition.
00:00:19.033 --> 00:00:24.632
How did the fire spread at a peak rate of spread of 130 meters a minute?
00:00:24.632 --> 00:00:28.373
This should have been a chance to show that everything went.
00:00:28.373 --> 00:00:40.671
Every layer of fire protection that exists went wrong in Mati and it was the time to assign responsibility when it should have been assigned, to show that there are so many more ways of fighting a fire short term, long term, whatever.
00:00:40.671 --> 00:00:49.298
And with this trigger boundary methodology methodology we want to show that suppressing a fire is not the only option hello everybody, welcome to the fire science show.
00:00:49.499 --> 00:00:56.148
I could record this intro a hundred times, but I don't think I would ever go close to how nick has introduced you into the subject.
00:00:56.148 --> 00:00:57.332
You don't know what it is yet.
00:00:57.332 --> 00:01:02.045
You may guess we're somewhere between engineering and wildfires, and that is true.
00:01:02.045 --> 00:01:17.801
In this episode we will be talking about wildfire preparedness and actually an engineering methodology that was developed in a project called Woonity, a very big project that we will be talking about and this part on imperial legend and under supervision of Guillermo Reyn.
00:01:17.801 --> 00:01:31.355
This is called the trigger boundaries and it's a very nice way to assess when communities should evacuate, when they should leave, when is the last moment they can safely evacuate from a wildfire that is approaching them.
00:01:31.355 --> 00:01:48.287
My guests today are two PhD students from Imperial Well, dr Harry Mitchell you've heard him before in the podcast on the smoldering of timber, and Harry's done a lot of work on trigger boundaries as well and my second guest, nick Algaropouloulos, who you've just heard seconds ago.
00:01:48.287 --> 00:01:52.621
He has a really powerful story behind him doing this job.
00:01:52.621 --> 00:01:55.888
He has firsthand experience with wildfires.
00:01:55.888 --> 00:02:02.400
He's very charismatic and has done a lot of research to take the very first simple model they came up with into a probabilistic simulator.
00:02:02.400 --> 00:02:11.787
So if you're hesitant to stay with us because this is wildfires and you don't do wildfires, oh boy, it's totally worth it, and I'm sure many of us will be doing wildfires in the future.
00:02:11.787 --> 00:02:17.466
Here we are given a tool that we can work with and, as engineers, we have to appreciate that.
00:02:17.466 --> 00:02:20.393
So let's spin the intro and jump into the episode.
00:02:31.640 --> 00:02:32.822
Episode.
00:02:32.822 --> 00:02:34.903
Welcome to the Firesize Show.
00:02:34.903 --> 00:02:43.072
My name is Wojciech Wigrzyński and I will be your host.
00:02:43.072 --> 00:02:48.757
This podcast is brought to you in collaboration with OFR Consultants.
00:02:49.300 --> 00:02:51.618
Ofr is the UK's leading fire risk consultancy.
00:02:51.618 --> 00:03:02.532
Its globally established team has developed a reputation for preeminent fire engineering expertise, with colleagues working across the world to help protect people, property and environment.
00:03:02.532 --> 00:03:18.343
Established in the UK in 2016 as a startup business of two highly experienced fire engineering consultants, the business has grown phenomenally in just seven years, with offices across the country in seven locations, from Edinburgh to Bath, and now employing more than a hundred professionals.
00:03:18.343 --> 00:03:30.002
Colleagues are on a mission to continually explore the challenges that fire creates for clients and society, applying the best research experience and diligence for effective, tailored FHIR safety solutions.
00:03:30.002 --> 00:04:00.554
In 2024, ofr will grow its team once more and is always keen to hear from industry professionals who would like to collaborate on FHIR safety futures this year, get in touch at ofrconsultantsc om.
00:04:00.554 --> 00:04:04.776
We confirmed that Kari has not quit, so that's a good one.
00:04:04.776 --> 00:04:09.387
That was a funny one, and first time in the podcast, nikolas Kalogorapus.
00:04:09.387 --> 00:04:11.189
Hello, nik, good to have you in the podcast.
00:04:11.471 --> 00:04:14.064
Hello, thank you for having me Long time listener so far.
00:04:14.064 --> 00:04:14.768
First time speaker.
00:04:15.099 --> 00:04:16.766
Perhaps not a one-time comer.
00:04:16.766 --> 00:04:18.547
We'll see after this episode.
00:04:18.547 --> 00:04:32.524
Great to have you both, and the topic for today is something that you have been both working on in Imperial for many, many years as a part of collaboration called the WNITI, and that is the trigger boundaries.
00:04:32.524 --> 00:04:57.050
In the general theme of wildfire evacuation, I saw Nick's talk on IFSS and that was really, really interesting and I thought that the concept is quite brilliant and could be applied not just to wildfires but in many places like industrial fire safety or perhaps even in some way moved into the world of buildings, so I'm super happy to have listeners learn about it.
00:04:57.091 --> 00:05:14.339
So let's start with the idea what the trigger boundary is and what's the place of that in fire safety is and what's the place of that in fire safety I guess I'll start so trigger boundaries came about when we were looking into how we can use, you know, engineering mindset and mathematics to improve community fire safety.
00:05:15.079 --> 00:05:29.630
One of the things we found from, I think, professor Tom Kova, his team in the US was they used a methodology where they find an imaginary line around the community, to talk in fire safety terms, where R set equals A set.
00:05:30.220 --> 00:05:34.190
I'll explain for people that you know don't have a trying to approve document B.
00:05:34.190 --> 00:05:44.350
So it's a line where the available time to evacuate, dictated by the progression of the fire, is equal to the required time to evacuate for the whole community.
00:05:44.350 --> 00:05:53.370
So when the fire reaches this imaginary line around the landscape, the population has an exact amount of time to evacuate before the fire reaches them.
00:05:53.370 --> 00:06:00.166
If an evacuation happens before that line, then the entire community will have evacuated before the fire reaches them.
00:06:00.166 --> 00:06:04.038
If an evacuation starts after the fire has crossed this boundary, then there is a chance that people will still be in the community when the fire reaches them.
00:06:04.038 --> 00:06:09.254
If an evacuation starts after the fire has crossed this boundary, then there is a chance that people will still be in the community when the fire reaches them.
00:06:09.254 --> 00:06:13.144
It's a sort of line to mark the last chance of safe evacuation.
00:06:13.605 --> 00:06:17.353
Okay, and at what scale is it determined?
00:06:17.353 --> 00:06:23.146
Is it like for a single house, for a single person, for a town, a region?
00:06:23.848 --> 00:06:31.110
It's determined in a per community basis, essentially depending on the evacuation strategy that someone might have.
00:06:31.110 --> 00:06:41.221
They might decide that the best way to evacuate a community is all at once, or they might decide that they can do they can evacuate a bigger parcel of land in stages.
00:06:41.221 --> 00:06:58.529
We take that minimum parcel of land that has been decided on and, with the help of collaborators like Enrico from Lund, we estimate how long it will take for that community to be evacuated and do the analysis for that scope.
00:06:58.529 --> 00:06:59.291
That scale.
00:07:00.120 --> 00:07:06.800
I think the concept is, at the same time, very simple but very powerful.
00:07:06.800 --> 00:07:15.954
So you basically know that if this line is crossed, there is no more chance for safe evacuation and you risk that someone will get hurt in the fire.
00:07:15.954 --> 00:07:35.211
And you also know that if the fire is 10 kilometers from that line, you perhaps can use other strategies to mitigate or, you know, keep, because, like what people do when the fire comes, they would prepare their households or well-being for the incoming fire and then hopefully they would evacuate.
00:07:35.211 --> 00:07:41.259
So perhaps you have more time to prepare or, in terms of industry, perhaps you don't need to shut down the factory.
00:07:41.259 --> 00:07:46.273
That was also an interesting discussion I just had with Eulalia Planas some weeks ago in the podcast.
00:07:46.273 --> 00:07:50.011
So a very simple but yet a very interesting concept.
00:07:50.011 --> 00:07:54.129
What does it mean that the fire crosses the line?
00:07:54.129 --> 00:07:56.148
Like what exactly crosses the line?
00:07:56.148 --> 00:07:59.269
The flames, the smoke, the firebrands?
00:07:59.882 --> 00:08:02.108
So this is actually a really interesting point.
00:08:02.108 --> 00:08:07.343
This is actually a really interesting point.
00:08:07.343 --> 00:08:12.720
So the purpose of the trigger boundary is that it gives adequate time before the quote-unquote fire reach the front of the fire, reaches the community.
00:08:12.720 --> 00:08:21.853
But that isn't necessarily when things will become untenable for the community itself.
00:08:21.853 --> 00:08:34.745
So at the moment, just because it's what is available in terms of modeling capabilities, the trigger time itself is defined by the where the actual wildfire spread front reaches the trigger boundary.
00:08:34.745 --> 00:08:42.628
But I suppose there would need to be other considerations in reality as well, like when do firebrands pass the trigger boundary?
00:08:42.628 --> 00:08:45.432
When does smoke pass the trigger boundary as well?
00:08:45.432 --> 00:08:55.082
Because, as we're seeing in the larger woundity project, smoke is quite a big consideration in the capacity of a community to evacuate.
00:08:55.082 --> 00:09:04.629
You know, if people driving through smoke where they can barely see in front of themselves, then that's seriously going to impede their capacity to evacuate.
00:09:04.629 --> 00:09:10.830
So there are other considerations that need to come into it when we're getting into more complex models.
00:09:11.139 --> 00:09:14.471
We know that the smoke will affect the evacuation, definitely.
00:09:14.471 --> 00:09:19.493
But in terms of the simplest, visibility affects evacuation speed.
00:09:19.493 --> 00:09:21.466
There's a paper by Rico Ronchi on that.
00:09:21.466 --> 00:09:35.647
There's also the concept of is it safer for people to evacuate or is it safer to stay in place if there is a lot of smoke outside and if their building and community preparation is that that allows them to stay in place?
00:09:35.647 --> 00:09:36.408
All right.
00:09:36.408 --> 00:09:39.361
Now we have some modeling to deal with smoke.
00:09:39.361 --> 00:09:43.009
It can be implemented in the three-year boundary methodology.
00:09:43.009 --> 00:09:46.254
It's not implemented in the models we have so far.
00:09:46.254 --> 00:10:03.190
It of course depends on what fuel might be burning, how the wind might be, if there's a lot of smoldering, because we've seen that the flaming part of the fire produces a lot of smoke but it's very hot and goes up, whereas the smoldering part of the water produces colder smoke, which is what ends up going into the communities.
00:10:03.190 --> 00:10:11.311
So there's a lot of interconnectivity at play that can come into the methodology and the framework of trigger boundaries.
00:10:11.311 --> 00:10:15.427
But to select models that can do everything at once is a bit tricky.
00:10:15.787 --> 00:10:21.067
There's so many components that must go into that first, like two separate trees of modeling.
00:10:21.067 --> 00:10:22.511
First the modeling, the evacuation.
00:10:22.511 --> 00:10:35.931
So you need to know how much time actually people need to escape and all the possible scenarios in which the wildfire approaches the community, which will be dictated by the direction of wind, the speed of wind, if it's slow or not.
00:10:35.931 --> 00:10:38.061
Uh, how dry is the fuel?
00:10:38.061 --> 00:10:38.923
How much the fuel is?
00:10:38.923 --> 00:10:40.908
There must be so much, so much into it.
00:10:40.908 --> 00:10:44.106
We'll we'll try to dig into that.
00:10:44.106 --> 00:10:51.009
But first I need to also understand what's the point of doing this extremely complex modeling task.
00:10:51.009 --> 00:10:55.847
How do you see this, perhaps affecting the safety of communities?
00:10:55.847 --> 00:10:59.748
Or what's the rationale behind developing this complex methodology?
00:11:00.559 --> 00:11:06.090
The overall aim of it is to inform safer and more reliable evacuations.
00:11:06.090 --> 00:11:13.013
So around 2% to 3% of wildfires in the northern US, for example, spread into urban areas.
00:11:13.013 --> 00:11:21.408
And when a wildfire spreads into an urban area, stay put isn't always going to be the most effective method of defending the population.
00:11:21.408 --> 00:11:38.610
There will become a critical point where you might need to evacuate, but currently there aren't many resources or tools beyond firefighter intuition that define when is the time where we actually need to call an evacuation.
00:11:38.610 --> 00:11:44.205
So there's a lot of obviously there's a lot of research into wildfire spread modeling.
00:11:44.666 --> 00:11:50.695
So semi-empirical models like Farsight and Flammat and Prometheus, and the list goes on and on and on.
00:11:50.695 --> 00:11:55.030
And then there's a mountain of research into evacuation modeling as well.
00:11:55.030 --> 00:12:05.980
But the interaction and how to couple and interpret both of those phenomena together is heavily understudied and undercharacterized.
00:12:05.980 --> 00:12:26.393
So essentially, the point of trigger boundaries is to sort of bridge that gap, to try and understand okay, when do we need to evacuate people so that they don't end up evacuating into or towards the fire, or before, how do we evacuate them before fire starts to impede the evacuation route?
00:12:26.393 --> 00:12:26.874
Also?
00:12:27.221 --> 00:12:43.885
the delayed evacuation, especially if you have limited capacity to escape, like if you're in a alpine village with just one road, or I think, nick, you are showing an example from greece of matty fire, where it was also impeded.
00:12:43.885 --> 00:12:48.214
If the evacuation is delayed, it's obvious that the consequences will be there.
00:12:48.214 --> 00:12:51.791
But I would love to understand, like, what could be the consequences?
00:12:51.791 --> 00:12:59.628
Like how does it look when the evacuation is started, after those, let's say, trigger boundaries which were not known are crossed?
00:13:00.080 --> 00:13:02.822
Yeah, this is unfortunate, talking about any.
00:13:02.822 --> 00:13:06.052
You know, delayed evacuation in a wildfire is not a pleasant story.
00:13:06.052 --> 00:13:13.779
In my case, I have family in Matti, which was subject to the Matti fire of 2018, with 104 people dead.
00:13:13.779 --> 00:13:20.504
Thankfully, everyone from my family is safe, but, you know, the house next to us is gone A few hours after that.
00:13:20.504 --> 00:13:21.086
It's gone.
00:13:21.086 --> 00:13:30.004
Thankfully, not many people that we knew that were victims of the fire, but some people adjacent to us on the buildings opposite us did not make it.
00:13:30.004 --> 00:13:33.850
So we've seen the worst that can happen in a delayed evacuation.
00:13:33.850 --> 00:13:56.823
The worst thing that can happen is that people might just not know what is going on In Matti, in that area, as I was like I grew up there Even since you, even since I was eight or nine I was used to seeing the sky turn orange, the firefighting helicopters coming down to the seaside to pick up water, so people were used to seeing smoke.
00:13:57.225 --> 00:14:13.251
And when there's smoke over your area, maybe you don't believe that it's a fire that's headed to your place, and in the case of Malta, so many things went wrong that people realized that they were in danger when trees next to them started catching fire because of firebrands.
00:14:13.251 --> 00:14:18.111
So the worst thing that can happen in delayed evacuation is that people don't know that they're in danger.
00:14:18.111 --> 00:14:36.172
And if you don't know you're in danger, you haven't made evacuation plans, and the architecture of the community such that most buildings have wooden roofs, which means that you cannot make it a safe place to stay in place and avoid for it to pass, then your only option is to try and evacuate.
00:14:36.172 --> 00:14:53.143
And if the road network is subpar and there is no coordination for evacuating cars, what can happen is a blockage, when either a car breaks down or there is too much traffic for the road network to handle, not the moment one person decides to abandon their car and go somewhere else.
00:14:53.143 --> 00:14:54.706
In the case of Mati, run to the beach.
00:14:54.706 --> 00:14:55.828
That's it.
00:14:55.828 --> 00:15:00.750
The entire ingress route is blocked off, and in Mati there was only a north and south route.
00:15:00.789 --> 00:15:01.110
Anyway.
00:15:01.110 --> 00:15:02.501
That can happen.
00:15:02.501 --> 00:15:05.788
Some people decide to stay in their cars because the smoke is way too dense.
00:15:05.788 --> 00:15:08.953
Some people go to the beach, but the smoke is still way too dense.
00:15:08.953 --> 00:15:15.416
So, yeah, delaying an evacuation can lead to tragedy, and most often does.
00:15:15.416 --> 00:15:24.903
We refer to such phenomena as dire evacuations, when people attempt to evacuate without enough time to do so safely, and we see it time and time again.
00:15:24.903 --> 00:15:38.130
We saw it in 2018 in Mati, in the Camp Fire, in 2023 in the La Jaina Fire in Portugal, in the Pedro Gao Fire, in individual cases, in the Black Saturday fires in Australia.
00:15:38.130 --> 00:15:40.028
It happens time and time and time again.
00:15:40.028 --> 00:15:54.254
Circumstances are such that an evacuation either occurs or has to occur when there's not enough time to do so safely, either because of the strength of the winds, the dryness of the fuel or just the delayed process of starting the evacuation.
00:15:54.799 --> 00:15:57.168
You've wrote something that resonates very strongly with me.
00:15:57.168 --> 00:16:03.552
That's that for laymen it's very difficult to tell how dangerous is the fire.
00:16:03.552 --> 00:16:06.087
It's related to risk perception of fires.
00:16:06.087 --> 00:16:27.846
There has been a lot of research on that and even you know, I'm, with my limited experience with fire scientists visiting my, my laboratory, technically, people who are extremely well educated in in terms of fire sometimes seeing those you know, 10 megawatts fire out of nothing feels really scary and you've been to cold dreads and stuff.
00:16:27.846 --> 00:16:29.311
You know how a big fire is.
00:16:30.341 --> 00:16:42.509
And even if you're ready for it, it's still surprising sometimes, and if you're a layman, especially if you've seen those images of orange sky, the orange sky will not be oranger because it's more dangerous.
00:16:42.509 --> 00:16:50.173
Right, it's different things that indicate that you're in danger or not, and as a layman, there's absolutely no chance you can tell.
00:16:50.173 --> 00:16:56.528
There's no way out of your experience you'll be able to just say, oh yeah, this time it's really bad.
00:16:56.528 --> 00:17:13.426
Perhaps in some indigenous communities where this knowledge was passed from generation to generation and they just lived in an area that has burned every three years, perhaps they've built a community intuition, but it's not something we should trust on when designing an evacuation process, right?
00:17:13.426 --> 00:17:18.981
So I guess here the winity and furthermore, the trigger boundaries come in.
00:17:18.981 --> 00:17:22.365
The first iteration of that was called the PERIL model.
00:17:22.365 --> 00:17:23.898
Am I correct, harry?
00:17:24.781 --> 00:17:25.836
Yeah, absolutely so.
00:17:25.836 --> 00:17:30.326
It was the Population Evacuation Trigger Algorithm.
00:17:30.326 --> 00:17:36.304
Okay, the acronym doesn't quite line up, but we'll glaze over that Close enough For a pre-chat GPT times?
00:17:36.324 --> 00:17:36.904
we'll glaze over that.
00:17:36.904 --> 00:17:38.067
Close enough For a pre-ChatGPT times?
00:17:38.067 --> 00:17:41.616
I would say that that's close enough, you could probably get closer.
00:17:41.636 --> 00:18:10.919
I think ChatGPT would have got relatively close to that, though I'm happy with that, but yeah, so basically the idea of Peril was to introduce a simple, robust trigger boundary model to the Woonity engine, which essentially for those who don't know is essentially a software package that's being developed, led by the Fire Protection Research Foundation at the NFPA, along with a few of us at Imperial, lund, movement Strategies, nrc and RMIT.
00:18:11.319 --> 00:18:23.268
But basically the idea is that Peril could take one data from a wildfire spread scenario and an evacuation scenario and then develop a trigger boundary around the community from that.
00:18:23.268 --> 00:18:30.067
And also nice thing about it as well is that it doesn't necessarily have to be a model or it.
00:18:30.067 --> 00:18:31.635
It can actually.
00:18:31.635 --> 00:18:35.220
Peril can actually be supported by data like actual experimental data.
00:18:35.220 --> 00:18:59.065
So, for example, one part of the Woonity project was that our team ran an evacuation drill in a WooWee community called Roxburgh Park, essentially just asking I think it was, I can't remember maybe like 10% of the community to evacuate once evacuation notice was given, and from that we got an approximation of the required evacuation time.
00:18:59.065 --> 00:19:05.714
So, for example, that data could be inputted into Peril and use that to support developing a trigger boundary.
00:19:06.155 --> 00:19:10.207
But there's like infinite ways the fire can grow and spread right.
00:19:10.207 --> 00:19:14.747
If you have no wind, it's going to spread very slowly.
00:19:14.747 --> 00:19:19.266
If there's a strong wind, it's going to be a completely different outcome.
00:19:19.266 --> 00:19:23.747
If it's going uphill, it's going to be different than if it's coming to your village from downhill.
00:19:23.747 --> 00:19:27.095
So how does the model take it into account?
00:19:27.095 --> 00:19:35.808
You perform countless amounts of fire spread simulations and then fuel in and compare that with your evacuation simulation.
00:19:35.808 --> 00:19:36.309
How does it work.
00:19:36.775 --> 00:19:46.844
So the first iteration of the model, the AeroAlp, only took into account a single run of both an evacuation and a wildfire simulation model.
00:19:46.844 --> 00:19:53.048
So you could say it's like a scenario-based trigger boundary Absolutely.
00:19:53.048 --> 00:20:13.442
So you take one case of okay, for example, we had a UK case study called Swinley Forest, which was a wildfire that happened I think in the early 2000s, which was modeled heavily by Tom Smith and the University of Greenwich, where basically they took burn data and then calibrated a wildfire spread model to that.
00:20:13.442 --> 00:20:34.743
So you can take a single scenario and then do it like that or, as nick then developed into the next iteration of the model, you can take multiple evacuation scenarios or multiple wildfire spread scenarios and develop something that's a bit more generic, rather a bit more one-fits-all in terms of what a community could see.
00:20:34.743 --> 00:20:39.290
Because, as we're getting sort of this, climate change is impacting things more and more.
00:20:39.290 --> 00:20:46.887
We are seeing more extreme wildfire spread scenarios, which will obviously make things much more complicated when it comes to evacuation.
00:20:47.494 --> 00:20:48.038
Before I leave.
00:20:48.038 --> 00:20:54.506
Nick, I'll follow up on this earlier because I think on this simpler case it's easier to clear out some ideas.
00:20:54.506 --> 00:20:58.443
So, is the trigger boundary a single number?
00:20:58.443 --> 00:20:59.467
Is it a spectrum?
00:20:59.467 --> 00:21:11.865
Do you put any safety margin in that or you just say, okay, like 17 minutes is the trigger boundary and it's up to you to decide whether you like to evacuate 30 minutes or 10 minutes before.
00:21:12.335 --> 00:21:18.407
So in the first iteration, peril, there was a safety factor implemented in it, but not natively.
00:21:18.407 --> 00:21:27.942
For example, if you wanted to model a specific fire and a specific community evacuation, you could put a safety factor on the community evacuation time.
00:21:27.942 --> 00:21:29.059
That's how you would apply it.
00:21:29.059 --> 00:22:05.433
After that the story goes I joined the Haze Lab and one of my first tasks was to take the work of Harry and try to integrate it into the wider Woonity project, university of Melbourne Movement Strategies, funded by NIST and managed by the National Fire Protection Association in the US, where we are the first to attempt a unified coupled wildfire evacuation model.
00:22:05.433 --> 00:22:25.258
So the first platform, let's say that encompasses both wildfire simulations, pedestrian evacuation simulation and vehicular evacuation simulation, because when you have there's a lot of models that do the three independently, we're the first ones to try and do so in a unified content, and one of the great outcomes of such research is trigger boundaries.
00:22:25.258 --> 00:22:31.678
So when I joined I was tasked with trying to do, you know, the nitty-gritty coding stuff to go from R development to Unity.
00:22:31.678 --> 00:22:42.415
And as I was doing it, enrico asked what would happen if I wanted to test out a fire coming, you know, both from the north starting there and from the south, starting there.
00:22:42.415 --> 00:22:50.039
What if I want a boundary for those two fires and for a third fire that you know happened on a low moisture content day.
00:22:50.039 --> 00:22:52.644
That expanded to what if we test 10,000 fires?
00:22:54.028 --> 00:23:03.875
By the end we realized that instead of studying single scenarios with a specific fire ignition point with quite a drastic evacuation, what if we try and do it probabilistically?
00:23:03.875 --> 00:23:10.523
The way I explained this in presentation is imagine if we had to evacuate this room right now.
00:23:10.523 --> 00:23:14.882
I could time you and take a very specific amount of time to evacuate this left theater.
00:23:14.882 --> 00:23:15.743
But what if I needed to know how specific amount of time to evaluate this lecture?
00:23:15.743 --> 00:23:23.888
But what if I needed to know how long it will take to evaluate this room tomorrow or with another class or in a year from now?
00:23:23.888 --> 00:23:30.023
At that point you can't have a precise number, but what you can do is you can have a range of possible numbers.
00:23:30.023 --> 00:23:42.061
It might be slow, it might be fast, it might be a slow day after lunch, it might be a day where it's only first year undergraduates, so they're very speedy to go, so on.
00:23:42.061 --> 00:23:44.250
We took trigger boundaries to the same direction, so we can model a single fire and a single evacuation.
00:23:44.250 --> 00:23:52.880
But what if we want to study what will happen on any possible fire that might threaten this community for any realistic evacuation time.
00:23:53.482 --> 00:24:01.722
What we're doing now is we are stimulating single fires again, yes, but we're doing so in an assembled fashion as you described.
00:24:01.722 --> 00:24:05.621
We're doing hundreds of simulations until convergence is achieved.
00:24:05.621 --> 00:24:06.384
What does that mean?
00:24:06.384 --> 00:24:07.559
I'll leave it as a question mark.
00:24:07.619 --> 00:24:36.929
But until we're satisfied with the result, we run individual peri-studies and bundle them all together in the end, by the end, instead of the fictional line that we were talking about before, where it evaluated before the parity line, you say if after there's a bit of a problem, now we have this sort of band, I'd say, around the community, by that evaluation, completely outside of the band, you have a 100% chance of evacuating on time.
00:24:37.335 --> 00:24:41.255
100% chance when it comes to the model input parameter you selected.
00:24:41.255 --> 00:24:52.185
And as you delay your evacuation and the fire progresses towards the community and into this band, your probability of evacuating safely decreases.
00:24:52.185 --> 00:24:56.432
You might delay your evacuation by a bit and you might decrease it so that now you have an 80% chance of evacuating safely decreases.
00:24:56.432 --> 00:25:00.405
You might delay your evacuation by a bit and you might decrease it so that now you have an 80% chance of evacuating safely.
00:25:00.405 --> 00:25:04.118
You might delay it more and now you have a 40% chance of evacuating safely.
00:25:04.118 --> 00:25:11.118
This percentage the way we do it now comes from doing repeat simulations based on the historic wind.
00:25:11.118 --> 00:25:23.423
So we would look at the weather station data for the last 20 years, find what's the average daily maximum wind, that's the average daily minimum humidity, and how does that vary within a month?
00:25:23.674 --> 00:25:29.742
But the percentage is related to all fires that can expect, so it's not like you have a 40% chance.
00:25:29.742 --> 00:25:36.784
It's that in 40% of fires you would escape and in 60% fires you would escape and in 60% fires you would not.
00:25:36.784 --> 00:25:42.625
Based on your inputs, because for every single fire the trigger boundary will be in some different place, right?
00:25:43.287 --> 00:26:03.862
Yes, the percent chance tries to relay the fact that, based on historic wind, if you start an evacuation when the fire is at this point, the wind temperature, humidity, fuel moisture content is such that on the 60th decile of wind you will not have enough time and on the 40th decile you'll have time.
00:26:03.862 --> 00:26:08.605
But it's not just wind, it's all those parameters that dictate fire behavior bundled together.
00:26:09.095 --> 00:26:39.604
It's really interesting because, at one hand, it's a scenario-based tool which tells you the location of the boundary in a single scenario, and what you're doing here is an extremely difficult task and I know that because we were doing similar things with winds and fire to just create a number, one output out of hundreds of possible scenarios, each with a very, very small probability, because the probability of each individual wind is very low.
00:26:39.604 --> 00:26:43.425
There's like 2% of Western wind with five meters per second.
00:26:43.425 --> 00:26:54.005
These are very low probabilities, right, but the fun part about wind is that, even though it's a collection of low probability events like each wind has its very low probability, you always have one.
00:26:54.005 --> 00:27:00.939
So, like the probability you will have one of them is 100 percent, because that's the windrows, that's all the historical wind, very, very interesting.
00:27:00.939 --> 00:27:08.384
One more thing that I need to clear so you said it was the first coupled approach Is the coupling bi-directional?
00:27:08.384 --> 00:27:15.040
Does it mean that your fire simulation influences the evacuation simulation?
00:27:15.040 --> 00:27:17.688
Do people move differently in different fire scenarios?
00:27:17.688 --> 00:27:20.323
Like you block roads and stuff like that?
00:27:20.916 --> 00:27:26.744
As far as I know last time we talked with the team, parts of fire do increase the evacuation.
00:27:26.744 --> 00:27:34.261
So the fire progressing might block off a road and make it inaccessible will change the evacuation dynamics.
00:27:34.261 --> 00:27:36.003
The fire will produce smoke of some visibility.
00:27:36.003 --> 00:27:36.868
That will change the evacuation dynamics.
00:27:36.868 --> 00:27:37.835
The fire will produce smoke of some visibility.
00:27:37.835 --> 00:27:39.942
That will affect the evacuation speed.
00:27:39.942 --> 00:27:44.605
There is no difference from the evacuation model to the fire model.
00:27:44.605 --> 00:28:06.184
I don't know how that happened, but one important thing to mention is that as of now we can but do not model firefighter intervention, because we want to model the worst case scenario, the worst case conditions, because we know that the fire will spread but we do not know that firefighting actually will happen like in Máté.
00:28:06.204 --> 00:28:08.906
This model- to some extent show the weak spots of the community.
00:28:08.906 --> 00:28:29.542
Like you know that if the fire is approaching from the west and your biggest road will be very soon cut off, you suddenly have the trigger boundary way, way further away than if it's approaching, let's say, from the south, when it's not going to cut your evacuation.
00:28:29.542 --> 00:28:31.742
Does the model show that Exactly that?
00:28:31.863 --> 00:28:36.646
Yeah, we can take the result of the trigger boundary model, which usually is a map.
00:28:36.646 --> 00:29:01.007
If we produce a map centered with a community and draw a line or a boundary around it, we can then use that as evidence-based decision making and say that if you have a fire coming from the west, your trigger boundary extends so far out because your main means of egress might be compromised, because it is dry shrubbery, which means that the fire is going to come in extremely quickly.
00:29:01.007 --> 00:29:19.964
Now you have a visual indication of your weakest points of entry from the fire and you can have a discussion with the community, with managers, with landscapers, of we need to do something about this direction, because this is a very high fire and truth direction.
00:29:19.964 --> 00:29:22.140
This is something that we take pride in.
00:29:22.140 --> 00:29:31.888
The model that we now have, we have produced a way of having numbers and evidence-based decision-making for community resilience.
00:29:32.734 --> 00:29:44.961
But still, I'm still wondering to what extent you could just run a parallel simulation while having a fire, because I'm not sure to what extent the wildfire modeling is used during wildfire events.
00:29:44.961 --> 00:29:59.902
But seeing the amount of development and interest in this area and knowing that there are a lot of tools to, for example, take the real-time wind data and put them into wildfire models, you perhaps could run it on the side to take decisions.
00:29:59.902 --> 00:30:06.246
Is this also something you have expected out of this software or it's just fully preparedness?
00:30:06.286 --> 00:30:06.666
based.
00:30:06.666 --> 00:30:14.402
Considering the computational time that it takes to develop a trigger boundary, I think it's something that is feasible, feasible.
00:30:14.402 --> 00:30:26.604
I think the only thing that is worth highlighting is that your trigger boundary is only going to be as reliable or accurate as the wildfire spread and the evacuation model and or data itself.