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2019-2020 Black Summer Bushfires - Coggle Diagram
2019-2020 Black Summer Bushfires
Key Facts
magnitude- categorised due to intensity. undetermined but predicted to be equated to or over 100,000kW/m^2
duration- unprecedented due to early start, starting in NSW july 2019. Major fires burning from Sep 2019 to Mar 2020, NSW experienced 240 consecutive days of burning.
Probability
Very high, low rainfall, drought
scale of spatial impact- 18 million hectares was burned over the states and territories.
Frequency
NSW Rural Fire Services reported over 11,000 bush or grass fires and 100 bushfires between July 2019 and Mar 2020
Definitions
A natural hazard is an atmospheric, hydrological and geomorphic processes and events in our environment that have the potential to affect people adversely.
A bushfire is a fire that burns in grass, bush or woodland and can threaten life, property and the environment. it is referred to as a wildfire outside of Australia. It is uncontrolled.
causes
natural
rainfall was 40 percent below national average, NSW ( began in mid 2017) and southern Queensland and others were going through droughts
these weather conditions impacted vegetation and fuel loads within forests and grasslands. dry lands made it easier for fires to spread and intensify quickly.
lightning- major ignition source for most bushfires across NSW, Vic and SA.
ember spotting- embers travel up to 40 km ahead of the fire. fire generated thunderstorms produce extreme winds and lightning, sparking more blazes. there were 90 fires by thunderstorms in SE Aus.
anthropogenic
human activities caused a small percentage of fires in NSW,
suspected causes of the fires included powerlines, deliberate, accidental ignition by machinery, back burning on private rural properties and arson.
in ACT and SA reported started by machinery.
impacts
economic
impacts included cost of recovery (re-building businesses), job losses, and the local economy's overall impact. stakeholders include primary producers ( farmers and pastoralists), companies involved in agribusiness and forestry, and the hospitality sector.
major impacts normally occur within rural and semi-rural areas. over 10,000 commercial and rural properties were damaged or destroyed.
8000 facilities and outbuildings in NSW, 892 non- residential buildings in SA
the tourism industry took a direct loss of $1.7 billion which caused a larger drop in the supply chain output. a further $4.5 billion was lost.
job losses - NSW 3171, VIC 1430, QL 1499, SA 516, WA 479, TAS 13, ACT 110, NT 75
environmental
over 450 threatened plant species and 293 threatened animal species occur in the footprint of the bushfires.
major implications on the fauna and flora within the ecosystem, these impacts are no always bad. the intensity was too much it burnt everything in its path.
in NSW 2.7 million hectares/ 37% of its national park were burnt, in VIC, 1.38 million hectares were burnt.
natural environments were affected like wet and dry sclerophyll forests, temperate forests and grassland.
estimated over 1 billion animals including birds, reptiles, terrestrial mammals were killed in NSW and VIC. in SA up to 5000 (estimated) koalas were killed.
434 million (estimated) tonnes of carbon dioxide were emitted from bushfires.
social
national death toll was 34, 9 firefighters (from AUS and USA), 26 deaths in NSW, 5 in VIC and 3 in SA.
over 3000 private properties destroyed and 1200 were damaged. NSW experienced the most property loss.
the fires caused loss in telecommunications, transport and inability to access the essential goods and services.
mental health issues like depression and anxiety increased greatly during the bushfires. nearly half were reported of having PTSD,
a poll from Jan 2020 showed 50% of adults were affected by smoke during the bushfires.
risk management strategies
prescribed burns
it is the intentional, controlled application of fire to vegetation, typically forests, that burn under the canopy to reduce fuel loads. in Aus prescribed bans are usually done every 1-7 years.
reducing fuel loads directly affects the fire behaviour. when a fire enters a pre burnt area, the fire intensity, including flame height and speed, reduces allowing firefighters a better chance to control it
risks
if not managed properly they can get out of control very quickly, creating an ignition source for a bushfire.
only allowed in the correct weather conditions. if too wet, dry or windy it can not be carried out, leaving high fuel loads
create negative social and environmental impacts.
environmentally-
-more frequent fires impact ecological processes, flora and fauna.
increased the amount of land exposed to wind and water erosion.
social- respiratory conditions, cardiovascular conditions, and asthma are caused due to smoke from the prescribed fires.
Overall
Professor James Sharples concluded that the available fuel load makes little to no difference in extreme fire conditions.
in the 2019-2020 Black Summer Bushfires, an area burnt in 2013 to slow fires did not slow or reduce severity and/or size of the fire.
housing adaptations
building a house in a bushfire prone area means several additional designs specifications and construction regulations must be met to reduce the risk of ignition ( amber attacks, radiant heat or fire front)
in recent bushfires these standards have proven to minimise impacts.
downsides/ risks
several other factors can influence the effectiveness- the age of the house, maintanence of protection zones, cost and fire intensity
90% of buildings in bushfire prone areas dont comply with bushfrie construction standards ( built before put in place)
building a new house or renovation to meet standards can add up to 100,00 over,
overall
it is likely the modifications in construction near bushfire prone areas can reduce impacts from fire, there is data limitations that make it difficult to really assess whether the benefits outweigh the costs.
human impacts
social impacts increased by people attempting to defend their properties, not evacuating properly and driving on roads that were too dangerous
lack of education and preparedness impacted the inability to stop the bushfires faster. the scale of fire took everyone by surprise, this lack of knowledge and preparation the losses in the NSW region.
there was weakness in aus bushfire management plans, firefighting resources, personnel and equipment were insufficient to deal with the intensity.
the increasing population in rural and semi-rural areas have the greatest impacts. the increasing sprawl of settlements and tourist areas where morei nfrastructure is built within fire prone environments, intensifies impacts.