Why did the Australian wildfires last for months? An in-depth analysis of the fire cycle and countermeasures

Hello everyone, I am the assistant of Australian Encyclopedia. Recently, some friends asked me aboutAustralia bushfire durationNow I will summarize the relevant issues and hope it will be helpful to those who want to know more.

1. The spatial and temporal dimensions of the Australian bushfires

The "Black Summer" bushfires that broke out in Australia in the summer of 2019-2020 lasted for240 days, the burned area reached 247,000 square kilometers, equivalent to the entire land area of the United Kingdom. This century's fire has forced us to face up to the cyclical characteristics of Australian fires:

• Natural fire cycle:The natural regeneration cycle of eucalyptus forest ecosystem is 30-100 years
• Annual fire season:The dry season from October to April of the following year constitutes the basic fire danger period
• Extreme Weather Windows:The triple superposition of temperature exceeding 45℃, relative humidity below 15%, and wind speed exceeding 60km/h

2. The fundamental cause of the fire

2.1 The "powder keg" of geography and climate

About 70% of the Australian continent has an arid/semi-arid climate, with an average annual rainfall of less than 600 mm. The southeastern Mediterranean climate zone and the tropical monsoon zone form a uniqueFire corridor, the accumulation of fuel in the dry season can reach 40 tons/hectare.

2.2 Biofuels accumulation paradox

Eucalyptus contains up to 4.5% of oil, and its fallen bark can form10-15 cm thick combustible layerParadoxically, moderate burning promotes the cracking of eucalyptus seed pods, but excessive fire prevention leads to excessive fuel accumulation.

2.3 Climate Change Amplifier

The latest CSIRO research shows that Australia's fire weather index has risen by 20% since 1950, and the number of extreme fire days has increased by 56%. 2019 was the hottest (average temperature +1.52℃) and driest (rainfall -40%) year on record.

3. The technological matrix of modern firefighting

IV. Important issues related to wildfires

4.1 Why is it so difficult to completely eradicate?

Underground fires can spread along the root system of trees to a depth of up to 1.5 meters, and may reignite even after the surface fire is extinguished.The underground fire broke through the surface after lurking for 28 dayscase.

4.2 How do animals survive the disaster?

Koalas climb wet branches at the top of trees, kangaroos can hop through fires in a row, and echidnas hibernate in burrows. But research shows there are still3 billion animalsDirectly affected by the fire.

4.3 How far-reaching are the effects of smog?

Sydney's PM2.5 concentration once reached 734μg/m³ (safety value 25μg/m³), and smoke circulation caused New Zealand glaciers to appearBrown-red ash deposits, and even drifted to South America 12,000 kilometers away.

V. Ecological wisdom in post-disaster reconstruction

Blue Mountains RegionThree-level repair strategy:

1. Emergency Stabilisation: Erosion control within 6 months
2. Medium-term rehabilitation: achieve vegetation coverage in 3 years
3. Long-term Restoration: 30 years of ecosystem reconstruction

Thank you for your reading. I hope this article can help you understandAustralia bushfire durationIn the face of climate change challenges, we need to scientifically understand the laws of fire, respect the power of nature, and make good use of technology. Welcome to follow our special series to get more knowledge about Australian ecological protection.