I made bushfire maps from satellite data, and found a glaring gap in Australia’s preparedness



Image courtesy of Greg Harvie, Author provided

Wallace Boone Law, University of Adelaide

On the night of January 9 2020, my wife and I secured our Kangaroo Island home and anxiously monitored the South Australian Country Fire Service (CFS) website for bushfire advice.

After many horrific weeks of bushfires, the winds had again shifted, and the fire front began a slow, nightmarish march eastward into the island’s central farmlands. Official warnings advised that the entire island was potentially under threat.

Landsat-8 false colour image of southwest Kangaroo Island, showing active bushfires on January 9, 2020.
Landsat-8, Author provided

As my good neighbours and volunteer firefighters headed off to battle the flames elsewhere on the island, I desperately wanted to find a way to help. With no firefighting training, I felt I physically had little to offer. But I reasoned that my skills and training in remote sensing and spatial science could potentially turn satellite information into useful maps to track the fires, in more detail than those provided by the Country Fire Service and Geoscience Australia.




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‘This crisis has been unfolding for years’: 4 photos of Australia from space, before and after the bushfires


While I was ultimately successful, it wasn’t quite as straightforward as I thought. And what I learned about access to good-quality and up-to-date satellite bushfire information surprised me.

Free satellite imagery is abundant; useful information is not

In principle, there are many good sources of free satellite imagery. But selecting, sourcing, understanding and processing a multilayered satellite image into an accurate burnt area map takes technical know-how that is beyond the reach of the people who need it the most.

We are fortunate to live in a time where satellite images are constantly uploaded to the web, often within hours of acquisition. There are many reputable sources for this information, including NASA Worldview, USGS Earth Explorer, USGS LandLook Viewer, and the Sentinel EO Browser.

These websites are gateways to the world of “big satellite data”, and I quickly found myself on a steep learning curve to efficiently navigate them and find recent imagery.

Once downloaded, the next hurdle I faced was how to process a data-rich satellite image into a meaningful and accurate map of the bushfire area. I scoured the internet for “how to” blogs, academic articles, spatial algorithms, and processing codes; these too are the products of much intellectual investment by global scientists, openly and freely available.

As a spatial scientist, I naturally found all this fascinating. But as a resident of an island under assault from bushfires, I also found it frustratingly time-consuming. I crashed my computer testing algorithms. I maxed out my hard drive. I spent hours on possibilities that turned out to be dead ends.

True colour satellite imagery is often the most accessible and easily understood, but it often lacks sufficient detail to clearly identify burnt areas. In this Sentinel-2 true colour image, approximately 210,000 hectares are burnt, but bushfire-impacted areas are barely visible without advanced image processing.
Sentinel-2, Author provided

Maps help to fight fires and recover from them

In the end, I produced burnt area maps from Sentinel and Landsat satellite images captured during the fires. I learned that this kind of information can indeed help firefighting and ecological recovery efforts, both during and after bushfires.

Initially I gave the maps to a group of farming friends who had been fighting fires around their properties for weeks. They told me the maps helped save time in assessing which areas had already burned, allowing them to focus on defending unburnt areas, and to make decisions on where to move livestock and install firebreaks.

The positive feedback inspired me to customise my processing techniques, so I could provide updates more quickly when new satellite images became available.

I embedded appropriate safety disclaimers into the maps and released them on Twitter and Spatial Points, a blog site managed by my research group at the University of Adelaide.

Within hours, I received messages that the maps were being used for ecological recovery efforts. The maps successfully highlighted remaining patches of habitat where endangered and vulnerable species had found refuge. Several government agencies even contacted me for burnt area information, which I’m told was used to assess infrastructure damage and habitat loss.

Processed Sentinel-2 satellite image. Red areas suggest burnt vegetation. Variation in red hues are caused by dominant vegetation type and soils.
Sentinel-2/W. Boone Law, Author provided

National knowledge gap

My experience shows there is a swag of free and regularly updated satellite imagery available, which when interpreted and presented appropriately can potentially be hugely helpful to firefighting and recovery efforts.

However, I am concerned that neither the general public nor decision-makers seem fully aware of the range of satellite information on offer. Nor is there a good understanding of the advanced technical skills needed to access and process imagery into useful map data.




Read more:
Yes, the Australian bush is recovering from bushfires – but it may never be the same


This leads me to wonder whether I have stumbled upon a glaring knowledge gap in Australia’s bushfire preparedness.

How can we overcome this technological and information bottleneck? I don’t propose to have all the answers, but I do believe it would be sensible for governments, industry and research agencies to invest in the kind of capabilities that I developed while trying to protect my own local community.

As Australia faces a future of more frequent and extreme bushfires, there will doubtless be many people who would be glad of this kind of information when they need it most.The Conversation

Wallace Boone Law, PhD Candidate, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Yes, the Australian bush is recovering from bushfires – but it may never be the same


Grant Williamson, University of Tasmania; Gabi Mocatta, University of Tasmania; Rebecca Harris, University of Tasmania, and Tomas Remenyi, University of Tasmania

As bushfires in New South Wales are finally contained, attention is turning to nature’s recovery. Green shoots are sprouting and animals are returning. But we must accept that in some cases, the bush may never return to its former state.

We’ve all read the devastating figures of destruction this fire season. More than 11 million hectares of land burned across the country over a period of about six months. There is some evidence more than one billion animals perished.

We can take some heart in the regenerative power of the Australian bush.
However, when we read of “recovery” in the media, we feel we must clarify what that might actually look like.

While Australia’s environment has evolved to adapt to fire, our research shows we can no longer assume it will recover completely.




Read more:
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A fiery future

We are scientists and social science researchers who work in transdisciplinary climate change projects, liaising with park rangers, farmers, policymakers, emergency services and local government.

Our work involves scoping future challenges in land management and developing a range of plausible future climate scenarios for south-east Australia.

Our experience told us something like this catastrophic climatic event was possible, but as researchers we weren’t prepared to see such an inferno this summer.

Although fires are natural in Australia, they’re now occurring at an unprecedented frequency and intensity in areas that, historically, did not burn. This new regime does not allow the effective recovery of natural systems to their pre-fire state.

Alpine ash to ashes

Fires in alpine ash forests (Eucalyptus delegatensis) are a good example of this.

Along with some eucalyptus trees, Australian flowering grass trees (Xanthorrhoea) are pyrophytic plants – which means they are adapted to survive in fire-prone habitats.
Natalie Maguire / Flickr, CC BY-SA

Unlike many eucalypt species which can re-sprout after fire, this species’ only means of recovery is through germination via a seed bank in the canopy, and rapid germination and growth of seedlings after fire.

Multiple fires in quick succession kill seedlings before they reach maturity, disrupting the tree’s reproductive cycle and leading to local extinction of the species in the landscape.

Alpine ash forests have endured repeated fires in recent years. In 2013, a blaze in Victoria burnt more than 31,000 hectares of the Alpine National Park.




Read more:
Ash to ashes – what could the 2013 fires mean for the future of our forests?


Vast areas have been burnt again in this season’s fires in the same places. Research reveals climate change is increasing the frequency and intensity of fires in the Australian Alps.

This ecosystem will not recover. It will instead transition into a new, different ecosystem, and many species which evolved to live in the original habitat, such as the alpine ash, will no longer be supported. They will be replaced by other vegetation types, such as other eucalyptus woodland, shrubland or grassland.

No more refuge

To further illustrate this point, take the Tasmanian pencil pine Athrotaxis cupressoides.

This slow-growing conifer native to Tasmania can live for up to 1,000 years. They are found in Tasmania’s highlands and sub-alpine regions – historically a Tolkien-esque landscape of moss and emerald green cushion plants, studded with thousands of tiny mountain lakes, called tarns.

But large fires across Tasmania’s pencil pine habitat in recent years, including those in 2016, reduced hundreds of isolated pencil pine communities to blackened skeletons. The stands of trees that remain are struggling to survive in a drying and warming climate.

Pencil pines, widely found in Tasmania, are not fire-adapted and are killed by bushfires.
David Bowman

All this is occurring in areas that historically did not experience fire, which allowed a suite of ancient, fire-sensitive species to persist.

As climate change worsens, the pencil pine will be restricted to even smaller areas. Higher temperatures and increased fuel loads increase the likelihood of destruction by fire. Areas where pencil pines have historically been protected will diminish in number and size.

Irreplaceable loss

In these cases and many others, animal species relying on these trees and their ecosystems are profoundly affected.

Well before the latest fires, Australia had an abysmal record on vertebrate extinctions. This summer’s fires have brought some animal species, including the Kangaroo Island dunnart, closer to extinction.




Read more:
Australia’s bushfires could drive more than 700 animal species to extinction. Check the numbers for yourself


Future fire seasons will not be normal events, or even some kind of stable “new normal”, to which humans and nature will readily adapt. We’re seeing a trajectory of change in which our climate will shift faster than most living things can tolerate.

The Australian environment evolved with fire and in past conditions, could recover from fire. However climate change has altered the rules irrevocably.

We can no longer rest assured that nature will bounce back, and that knowledge should be a wake-up call for the world.The Conversation

Grant Williamson, Research Fellow in Environmental Science, University of Tasmania; Gabi Mocatta, Research Fellow in Climate Change Communication, University of Tasmania; Rebecca Harris, Climate Research Fellow, University of Tasmania, and Tomas Remenyi, Climate Research Fellow, Climate Futures Programme, University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Here are 5 practical ways trees can help us survive climate change



Shutterstock

Gregory Moore, University of Melbourne

As the brutal reality of climate change dawned this summer, you may have asked yourself a hard question: am I well-prepared to live in a warmer world?

There are many ways we can ready ourselves for climate change. I’m an urban forestry scientist, and since the 1980s I’ve been preparing students to work with trees as the planet warms.

In Australia, trees and urban ecosystems must be at the heart of our climate change response.

Governments have a big role to play – but here are five actions everyday Australians can take as well.




Read more:
Go native: why we need ‘wildlife allotments’ to bring species back to the ‘burbs


1. Plant trees to cool your home

At the current rate of warming, the number of days above 40℃ in cities including Melbourne and Brisbane, will double by 2050 – even if we manage to limit future temperature rises to 2℃.

Trees can help cool your home. Two medium-sized trees (8-10m tall) to the north or northwest of a house can lower the temperature inside by several degrees, saving you hundreds of dollars in power costs each year.

Trees can cool your home by several degrees.
Shutterstock

Green roofs and walls can reduce urban temperatures, but are costly to install and maintain. Climbing plants, such as vines on a pergola, can provide great shade, too.

Trees also suck up carbon dioxide and extend the life of the paint on your external walls.

2. Keep your street trees alive

Climate change poses a real threat to many street trees. But it’s in everyone’s interests to keep trees on your nature strip alive.

Adequate tree canopy cover is the least costly, most sustainable way of cooling our cities. Trees cool the surrounding air when their leaves transpire and the water evaporates. Shade from trees can also triple the lifespan of bitumen, which can save governments millions each year in road resurfacing.

Tree roots also soak up water after storms, which will become more extreme in a warming climate. In fact, estimates suggest trees can hold up to 40% of the rainwater that hits them.

But tree canopy cover is declining in Australia. In Melbourne, for instance, it falls by 1-1.5% annually, mainly due to tree removals on private land.

Governments are removing trees from public and private land at the time we need them most.
Shutterstock

This shows state laws fail to recognise the value of trees, and we’re losing them when we need them most.

Infrastructure works such as level crossing removals have removed trees in places such as the Gandolfo Gardens in Melbourne’s inner north, despite community and political opposition. Some of these trees were more than a century old.

So what can you do to help? Ask your local council if they keep a register of important trees of your suburb, and whether those trees are protected by local planning schemes. Depending on the council, you can even nominate a tree for protection and significant status.

But once a development has been approved, it’s usually too late to save even special trees.

3. Green our rural areas

Outside cities, we must preserve remnant vegetation and revegetate less productive agricultural land. This will provide shade and moderate increasingly strong winds, caused by climate change.

Planting along creeks can lower water temperatures, which keeps sensitive native fish healthy and reduces riverbank erosion.

Strategically planting windbreaks and preserving roadside vegetation are good ways to improve rural canopy cover. This can also increase farm production, reduce stock losses and prevent erosion.

To help, work with groups like Landcare and Greening Australia to vegetate roadsides and river banks.

4. Make plants part of your bushfire plan

Climate change is bringing earlier fire seasons and more intense, frequent fires. Fires will occur where they hadn’t in the past, such as suburban areas. We saw this in the Melbourne suburbs of Bundoora, Mill Park, Plenty and Greensborough in December last year.

It’s important to have a fire-smart garden. It might seem counter-intuitive to plant trees around the house to fortify your fire defences, but some plants actually help reduce the spread of fire – through their less flammable leaves and summer green foliage – and screen your house from embers.




Read more:
Low flammability plants could help our homes survive bushfires


Depending on where you live, suitable trees to plant include crepe myrtle, the hybrid flame tree, Persian ironwood, some fruit trees and even some native eucalypts.

Gardens play a role in mitigating fire risk to your home.
Shutterstock

If you’re in a bushfire-prone area, landscape your garden by strategically planting trees, making sure their canopies don’t overhang the house. Also ensure shrubs do not grow under trees, as they might feed fire up into the canopy.

And in bad fire conditions, rake your garden to put distance between fuel and your home.




Read more:
Keeping the city cool isn’t just about tree cover – it calls for a commons-based climate response


5. What if my trees fall during storms?

The fear of a whole tree falling over during storms, or shedding large limbs, is understandable. Human injury or death from trees is extremely rare, but tragedies do occur.

Make sure your trees are healthy, and their root systems are not disturbed when utility services such as plumbing, gas supplies and communication cables are installed.

Coping with a warming world

Urban trees are not just ornaments, but vital infrastructure. They make cities liveable and sustainable and they allow citizens to live healthier and longer lives.

For centuries these silent witnesses to urban development have been helping our environment. Urban ecosystems depend on a healthy urban forest for their survival, and so do we.The Conversation

Gregory Moore, Doctor of Botany, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.