Out of control, contained, safe? Here’s what each bushfire status actually means



We’re used to images of firefighters with hoses, but more of the firefighting effort goes to clearing vegetation than spraying with water.
Dean Lewins/AAP

Thomas Duff, University of Melbourne

In this record-breaking bushfire season, notifications from emergency managers have become a familiar feature of Australian life. Terms like “out of control” and “contained” are regularly heard as descriptions of the status of fires, but what do they actually mean?

These terms vary slightly between Australian states and territory, but as similar firefighting strategies are used Australia-wide, the meanings are comparable.

The status of a fire is a description of the stage of the firefighting effort, not the nature of the fire or its likelihood of being a threat. This means that to understand what actions to take when an active fire is nearby, it’s important to follow the advice of your local fire and emergency information sources.




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‘Going’ or ‘out of control’

A fire described as “going” or “out of control” is one where parts of its perimeter are burning and have the potential to spread into unburnt areas.

The perimeter is the focus as it is where unburnt fine fuels (consisting of the litter on the forest floor, shrubs and bark) are being ignited and burning rapidly. The flames of these subside quickly, so the majority of a fire’s interior consists of blackened area where only heavy fuels such as logs and branches continue to burn.

A fire will be given the status “going” when it is first detected or reported to emergency authorities. The status may also be used for fires that were controlled and subsequently breakaway (escape control).

“Going” fires will typically be the subject of concentrated firefighting effort to prevent growth and minimise the impacts to things of value (i.e. lives, property, infrastructure and ecosystem services). However the term is inclusive of all fires that are able to spread, so encompasses everything from shrubs burning under a tree hit by lighting to intense firestorms.

Contained or “being controlled’

A “contained” fire is one with a complete containment line around its perimeter. “Being controlled” will have a complete or near-complete containment line. Containment lines (also called control lines or firelines) are the main way to stop bushfires spreading.

While our images of firefighters involve hoses spraying water against the flames, water is, in fact, inefficient because of the vast amounts needed to douse the large amounts of burning vegetation and the difficulty of maintaining supply in rugged terrain.

Instead, to stop fires spreading, firefighters create containment lines where all fuels are removed in bands adjacent to the fire’s perimeter. This prevents the fire reaching unburnt vegetation, starving the flames of new material to burn.

So how are containment lines created? Typically, with heavy machinery (often bulldozers), which scrape away all burnable material around the edge of the fire so nothing but mineral soil remains. In rugged terrain, this may be done by hand, by specialist crews using tools such as rakehoes and chainsaws.

Where there are existing areas of low fuel in the landscape, such as roads, bodies of water or previously burnt areas, firefighters may also include these as part of their containment strategy.

The containment line is built next to the burning fire edge, so the more intense or erratic a fire is, the more difficult and dangerous it is for crews to work.




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It’s not safe to construct a line where fires are spreading rapidly, producing many embers, behaving erratically, have deep flames or are exhibiting firestorm-type behaviours (where the fire is so intense it can generate extreme winds and even lightning).

At such times firefighters will either move to parts of the fire where behaviour is less intense (typically where the wind is pushing the flames away from unburnt fuel), apply indirect firefighting methods such as backburning (burning areas in front of the advancing fire) or retreat and focus on protecting life and property.

The exceptionally hot, dry and windy conditions of the 2019/20 fire season have resulted in many rapidly expanding bushfires that have overwhelmed the capacity of firefighters to build containment lines.

As a fire is being contained, crews will be assigned to patrol the already constructed parts of the line to prevent escapes. The burning-out of unburnt fuels within the containment lines may be done to reduce the chance this ignites and causes issues at a future date.

Under control, or ‘patrol’

A fire that’s “under control” has a full containment line around it, and there has been a degree of consolidation so fire escaping outside the lines is unlikely.

This consolidation is called “mopping up” or “blacking out”, and consists of crews working along the edge of the fire to extinguish or stabilise any burning material in the fire area within a set distance of the line.

Fire elevates the risk of trees falling, so at this stage there may also be work to identify and treat dangerous trees.

After line consolidation is complete, routine patrols to prevent escapes will continue for days to weeks until the fire is deemed safe.




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Safe

The final status applied to bushfires is “safe”. This is where deemed that no sources of ignition within containment lines have the potential to cause escapes.

Once a fire is declared safe, it’s assumed no longer necessary to maintain patrols and the fire can be left alone.

After the fire season it’s common for management agencies to rehabilitate the containment lines, to restore the site to its prior condition to protect biodiversity values and water quality.

The status of a fire can change – even fires thought to be safe occasionally break away when hot and windy weather returns. Regardless of whether there are known fires in your area, it is important to have a bushfire survival plan and to pay attention to the advice of your local fire and emergency information sourcesThe Conversation

Thomas Duff, Postdoctoral Fellow, Forest and Ecosystem Science, University of Melbourne

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

Explainer: why the rock art of Murujuga deserves World Heritage status



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Detail of a fish (likely black bream) on Enderby Island.
Photo Vic Anderson

Jo McDonald, University of Western Australia

The West Australian government has committed to pursuing a World Heritage listing for the rock art of Murujuga. Murujuga is the Aboriginal name for the Dampier Archipelago and the Burrup Peninsula in north west WA and is home to at least a million individual works of art.

Australia has some of the world’s richest and most diverse rock art. While rock art is found all around the globe, Australia is relatively unique because here there are still cultural connections between rock art and the people who created it.

At present, Australia has only three cultural World Heritage sites (of which only one – Kakadu – is listed for rock art). In contrast, France has over 30 World Heritage-listed rock art sites.

I and my colleague Peter Veth have argued that Murujuga rock art meets three criteria for outstanding universal value: because of the creative genius and skill of the artwork; the extraordinarily old and continuous engraving tradition; and the combined cultural landscapes of the area, including quarries, living sites, and shell middens.

These illustrate significant transitions in human history in the face of major changes in sea level and surrounding environment.

The boulders of Murujuga are home to more than a million works of rock art.
Shutterstock.com

Animals no longer found

When people first started using this landscape 50,000 years ago, it was located around 100 km from the coast. It was wetter and warmer than it is now – and the archaeological record of the coastal plain at this time demonstrates an entire group of animals no longer found in this part of Australia. Murujuga’s artists painted some of these animals, such as crocodiles.

Then, during the last ice age (between 30,000 and 18,000 years ago), the coastline was even further away (160 km). People were were living in the Murujuga Ranges at this time. There are a number of paintings of animals that are now extinct, such as thylacines and a fat-tailed species of kangaroo, which testify to the changing environment.

Speared fat-tailed kangaroo positioned on irregular boulder; Dolphin Island.
Photo J. McDonald.

Then, as the ice caps melted and the sea level rose, people became more concentrated on the new coastal landscape. Recent studies across the archipelago have demonstrated the scientific significance of the outer and inner islands of this cultural land and seascape.

Dugong, turtles and fish

Around 8,000 years ago, people began to construct houses. Art production at this time was in full swing. The most recent rock art includes dugong, turtles, fish as well as the small rock wallabies and quolls that now live on the islands.

Fish depiction (likely black bream), Enderby Island.
Photo Sarah de Koning.

As well as houses there are myriad stone arrangements, standing stones and terraces. This is a monumental hunter-gatherer-fisherperson landscape, which rivals the period in Europe when people were constructing stone monuments such as Stonehenge (except in Europe this occurred thousands of years later).

The artworks in Murujuga were made on the rocks using stone tools. Together they show how people have been living in the region for thousands of years, first as hunter-gatherers, and later with a focus on fishing.

Contemporary traditons

This rock art is still associated with contemporary traditions, ideas, and belief systems of traditional custodians. It is the widely-held belief that many Murujuga engravings represent and embody ancestral beings (Marga), while some of the standing stones are thalu sites, critical for the regeneration of key species such as a range of fish, birds and kangaroo, and even sandflies.

Five local Aboriginal groups hold native title in lands next to the archipelago – the Ngarluma, Yindjibarndi, Yaburara, Mardudhunera and Wong-gg-tt-too. Together, they are represented by Murujuga Aboriginal Corporation, which jointly manages Murujuga National Park with the WA state government. The peninsula and the islands are also listed as having National Heritage values. This listing excludes parts of the peninsula that have been previously damaged by industry.

Pelican, Murujuga.
Photo Sarah de Koning.



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National Heritage listing paves the way for Murujuga to become a World Heritage site. Recently, traditional custodians and others came together for a summit in Karratha and concluded resoundingly that World Heritage listing would be appropriate for Murujuga, and that it would help protect this extraordinary place.

Author Tim Winton also joined the push for World Heritage status.

Yesterday’s announcement is a significant moment for WA – which doesn’t have any Aboriginal cultural sites listed as World Heritage. And for the traditional custodians, it is the next step in their quest for recognition and greater protection of this place’s special significance.

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The Conversation

Placing Murujuga on the Tentative List is the beginning of the formal process to achieve World Heritage status. This will still take several years, but as the CEO of the Murujuga Aboriginal Corporation, Peter Jeffries, said yesterday, the traditional owners are now driving the process.

Jo McDonald, Director, Centre for Rock Art Research + Management, University of Western Australia

This article was originally published on The Conversation. Read the original article.

Is UNESCO World Heritage status for cultural sites killing the things it loves?



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Tourists take a photo of sunrise at Angkor Wat in 2016.
Shutterstock

Jo Caust, University of Melbourne

Hoi An is a beautiful coastal town in central Vietnam that escaped the devastation of the American War. In 1999, it was listed as a UNESCO World Heritage site because of the charm of its original architecture, river location, and continuity of cultural practices. UNESCO recognition has made it a major cultural tourism destination. In 2017, 3.22 million people visited, an increase of 22% on the previous year.

Authorities have introduced a ticketing system for visitors, but its purpose is to raise revenue and record tourist numbers rather than control them. The streets are relatively narrow. With the influx of mass tourism, some streets are impossible to walk in and the town has turned into an “ersatz” version of itself with all buildings turned into cafes and shops to service tourist needs. Many large tourist buses park for much of the day on the edges of the old town, to disembark and collect passengers, making an ugly impression as you enter.

Tourists on the Japanese Bridge in Hoi An.
Suree Pritchard/AAP

The local Vietnamese have been forced to move from the town’s centre to live on the outskirts. Ironically, while it is an important cultural tourism destination for its buildings, the culture of Hoi An has changed completely due to mass tourism. From once being a lively trading community, it is becoming a theme park.

In Cambodia, meanwhile, Angkor Wat is a major international cultural heritage site. It received UNESCO recognition in 1992. From 2004-14 visitor numbers to Angkor Wat increased by more than 300%. While the local authorities have introduced a visitors’ ticket to ostensibly control numbers (and bring in revenue), there are challenges from “wear and tear” as visitors touch structures and walk on ancient paths.




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The major challenge for Angkor Wat, however, is uncontrolled tourist development around the site. For instance, the construction of large hotels and the illicit tapping of groundwater have affected the water table beneath the temples, which in turn affects their stability.

Tourists at Angkor Wat in 2017.
Mak Remissa/AAP

While continuing to preserve the temples is not easy, the far greater problem is the lack of planning around the site, which has been left to the whims of the marketplace. Ultimately this unplanned development has the potential to destroy Angkor Wat itself.

The impact of mass tourism anywhere can be overwhelming, but it is compounded in communities in developing countries with less economic resources to undertake adequate protection or planning. The town of Luang Prabang in Laos faces similar issues to Hoi An. The local community is now mostly living outside the old town, which again has been given over to tourists and their needs.




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Other UNESCO World Heritage sites around the world are battling similar problems in dealing with mass tourism. The number of people travelling by air internationally has increased by an average of around 7% a year since 2009. This growth is expected to continue at a similar rate.

A river boat moors at the entrance to the Pak Ou Caves near Luang Prabang, Laos.
Stephen Johnson/AAP

As far back as 1972, UNESCO adopted the Convention for the Protection of the World Cultural and Natural Heritage. Two more conventions, adopted in 2003 and in 2005, further protect Intangible Cultural Heritage and the Diversity of Cultural Expression. The intent of these was to draw attention to cultural sites and practices to ensure their ongoing protection and longevity.

Achieving UNESCO status is an internationally competitive process. Nations want this recognition because they can promote a place or practice as a unique cultural tourism attraction.

Communities and nations do have obligations when they receive UNESCO recognition. They are expected to undertake various measures to protect the site or practice and ensure proper planning occurs. But while more attention may be applied to restoration or reduction of unsympathetic behaviour (for example, at Angkor Wat the authorities have introduced rules about appropriate clothing to be worn by visitors), the broader implications of increased visitation may not have been considered.




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Encouraging tourism as a means to improve the economic situation of communities can, in fact, destroy their uniqueness and cultural value. With the continuing increase in tourism, the situation will inevitably worsen.

The focus is at present on earning money from the site/practices, not preserving them. Mass tourism can damage sites irreversibly. Communities and countries have some hard choices to make.

Hoi An streetscape: most locals have been priced out of the centre of town and now live on the outskirts.
Suree Pritchard/AAP

With colleague Dr Mariana Vecco, I recently published a research article about these issues. Some of our recommendations for vulnerable sites include:

  • introducing control of visitor numbers as a matter of urgency
  • tighter planning controls on adjacent development
  • querying the use of sites for any tourist activities
  • auditing sites for damage already incurred.

All of this should occur if UNESCO status is to be continued. However, there is also a bigger conversation we need to have – should tourists visit vulnerable sites and practices?

The ConversationHoi An is still a beautiful town but the presence of “wall to wall” tourists mars it. Sadly, as long as UNESCO status is used more as a marketing device than a route to preservation, the situation will continue to deteriorate.

Jo Caust, Associate Professor and Principal Fellow (Hon), University of Melbourne

This article was originally published on The Conversation. Read the original article.

Australian Acacias Infesting South Africa


The link below is to an article that reports on the ‘pest’ status of Australian wattles in South Africa.

For more visit:
http://www.australiangeographic.com.au/journal/is-wattle-damaging-south-africas-water-supply.htm