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Droughts are lasting longer in Australia, particularly in some of our most populated regions, 91ɫ��Ƭ scientists have shown.

 tracking not only the forces that drive drought but the damage it leaves behind has revealed that droughts have lasted longer in Australia in recent decades, especially in areas with the most people and farms.

91ɫ��Ƭ researchers analysed drought trends across Australia between 1911 and 2020 based on rainfall shortages and falling river and dam levels.

Their analysis showed that, since 1971, the time spent under drought conditions has increased across most of Australia, especially in the southeast and southwest, which are densely populated and key breadbaskets.

The increasing dryness was especially felt during winter and spring, which are critical seasons for growing crops like wheat.

Lead author, 91ɫ��Ƭ PhD student Matt Grant, says the trend, which is expected to continue, is especially concerning because the regions where drought is more severe are also some of the most important to Australia’s economy and people’s welfare.

“Across early parts of the last century, it was wetter, but we can see that pattern has reversed since the 70s.

“In recent years, we’ve had this general sense that droughts are lasting longer. Our work puts data behind the intuition and confirms it.

“We expect this trend to continue, which increases water security risks for some of Australia’s major cities and rural towns and puts serious pressure on farming.”

He says it’s not yet possible to say whether these conditions are caused by climate change, because Australia has historically had large variation in rainfall.

“It’s not to say that climate change isn’t influencing drought, it’s that the natural swings in Australia’s climate are so large that it may take longer for a clear signal to emerge from the noise.”

The AI unravelling Australia’s drought secrets

The researchers used AI to find relationships between these conditions and hundreds of official drought records of crop losses and threats to important water reservoirs in the southeast of the country.

Co-author Dr Sanaa Hobeichi, who pioneered an earlier , says the approach helps answer long-standing questions in drought science.

“It wasn’t really understood how closely weather was reflected in actual drought impacts, but we could show they clearly mirror one another,” she says.

“The model links all the steps of a drought, from the first missed rain to documented consequences.”

She says the research also shed new light on some of the less visible drivers of drought.